JP4772718B2 - Railway vehicle drive system - Google Patents

Description

  The present invention relates to a railway vehicle drive device, and more particularly, to a technology for providing electric power storage means to enable storage of power generation energy during braking, and reusing the stored energy to supply power to the drive device.

  The railway vehicle is characterized by having a lower running resistance than that of an automobile because it travels when iron wheels roll on the rail surface. In particular, in a recent electric railway vehicle, a braking force is obtained by causing the main motor to act as a generator during braking, and at the same time, the electric energy generated by the main motor during braking is returned to the overhead line to be reused as the power running energy of other vehicles. Regenerative brake control is used. The electric railway vehicle equipped with this regenerative brake is capable of traveling with about half the energy consumption compared to an electric railway vehicle not equipped with a regenerative brake, taking advantage of the features of a railway vehicle with low running resistance. This is an energy-saving technique.

  By the way, when a regenerative brake operates in a railway vehicle, a partner that absorbs the regenerated electric power is required. Conventional general railway vehicles return electric power generated by a regenerative brake to an overhead line through a current collector provided in the vehicle, and reuse it as power running power for other vehicles traveling in the same power feeding section as the vehicle. When a plurality of vehicles are traveling in the same power feeding section, there is a high probability that there is another vehicle that is powered at the timing when the regenerative brake of one vehicle operates. On the contrary, when only one vehicle is traveling in the same power feeding section, there is no power running vehicle that absorbs the electric power even if the regenerative brake of the vehicle operates. For this reason, since the regenerative brake current returning to the overhead wire is very small, the DC voltage of the inverter device is increased by the regenerative power. As a result, the allowable voltage of the inverter device is exceeded, the regenerative brake is disabled due to high voltage protection, and thereafter, the regenerative brake does not operate and the vehicle is stopped only by the air brake, so that the energy saving effect by the regenerative brake cannot be obtained.

  Thus, in order to return the regenerative brake power to the overhead line, there is a limitation that a power running vehicle that absorbs the power is necessary. However, if a facility capable of storing regenerative brake power can be provided, the energy saving effect of the regenerative brake can be obtained regardless of the presence of other powering vehicles.

  The position where the power storage device is provided can be mainly in the case of being installed in the ground-side power supply facility or in the case of being installed in the inverter device on the upper side of the vehicle. When there are many vehicles traveling in the same power supply zone, it is possible to realize a lower cost in terms of economies of scale by providing a power storage device in the power supply facility than providing a power storage device in all the vehicles. However, as described above, if the number of vehicles is originally large, there is a high probability that regenerative braking power can be absorbed by other power running vehicles. For this reason, when a power storage device that absorbs regenerative brake power is required, it is considered that there are many cases where the power storage device is selected to be provided in the inverter device on the vehicle upper side.

  For example, Patent Document 1 discloses an example of a vehicle drive control device in which a power storage device that absorbs regenerative power is provided alongside an inverter device on the vehicle upper side. FIG. 9 shows an example of a device configuration in the case where a power storage device that absorbs regenerative power is provided in the inverter device on the vehicle upper side.

  During power running, inverter 105 receives power from power storage device 102 or DC power supply 108 and power storage device 102 and drives motor 106. During regeneration, regenerative power is regenerated to the power storage device 102 or the DC power source 108 and the power storage device 102. When the vehicle stops or coasts, the power storage device 102 is charged by the DC power supply 108 or discharged from the power storage device 102 to the DC power supply 108. The charge / discharge current of power storage device 102 is controlled by switching switching elements 111 and 112. Switching elements 111 and 112 operate at a high switching frequency when the current during charging / discharging of the power storage device is larger than a set current, and operate at a low switching frequency when the current is small. Further, when the power running / regenerative operation is performed only by the power storage device 102, the on / off states of the switching elements 111 and 112 are fixed.

As mentioned above, even when there is no other power-carrying vehicle that absorbs regenerative braking power, it is possible to achieve regenerative braking by absorbing the regenerative braking power with the power storage device mounted on the host vehicle and obtain an energy saving effect. One example is the vehicle drive control device disclosed in Patent Document 1.
JP 2005-278269 A

  By the way, the reason why the regenerative brake cannot be continuously operated is that, in addition to the case where there is no other traveling vehicle mentioned above, the current collector of the vehicle is separated from the overhead line, and the regenerative brake power cannot be physically returned to the overhead line. There is a situation. This is because there is a difference in the natural frequency between the overhead wire and the current collector because the dynamics system is different. For this reason, instantaneous separation due to vibration may occur, which is also referred to as “instant wire interruption” or “pantor separation”. Since the regenerative brake current cannot be returned to the overhead line even by the instantaneous interruption of the overhead wire, the DC voltage of the inverter device increases rapidly at the moment when the instantaneous interruption of the overhead wire occurs, and the regenerative brake expires due to overvoltage protection.

  With respect to the occurrence of the instantaneous interruption of the overhead wire, the regenerative brake expiration can be prevented by providing the power storage device in the inverter on the upper side of the vehicle and absorbing the regenerative brake current. However, when an instantaneous interruption of the overhead wire occurs, the regenerative brake current is instantaneously interrupted, while the regenerative brake current I_regen flowing through the inverter temporarily flows into the filter capacitor, so that the capacitance C causes an immediate action. Does not become zero, and instantaneous occurrence of overhead wire breakage cannot be detected instantaneously. However, as a result, the filter capacitor voltage, that is, the DC voltage V_dc of the inverter device is pushed up. The relationship between the regenerative braking current I_regen and the DC voltage V_dc of the inverter device during the instantaneous interruption of the overhead line can be expressed by the following equation using the capacitance C as the filter capacitor.

I_regen = C ・ (d / dt) V_dc Equation 1
In other words, the instantaneous break of the overhead wire cannot be determined instantaneously from the regenerative brake current I_regen, but the DC voltage V_dc of the inverter device suddenly increases due to the regenerative brake current I_regen when the overhead wire breaks. By obtaining the rate (d / dt) V_dc, it is possible to detect an instantaneous interruption of the overhead line. Specifically, it is possible to detect the occurrence of the instantaneous interruption of the overhead wire when the rate of time change (d / dt) V_dc of the DC voltage of the inverter device exceeds a predetermined value.

  However, in the vehicle drive control device disclosed in Patent Document 1, as shown in the description of the best mode for carrying out the invention, the switching elements 111 and 112 that control charging / discharging of the power storage device are current detectors. 13 is controlled based on information such as the charge / discharge current IS of the power storage device 102 detected at 13 and the load / regenerative current IL flowing through the inverter 105 detected by the current detector 14. It is not disclosed that the control is performed based on the DC section voltage information.

  That is, in the vehicle drive control device of Patent Document 1, when it is sufficient to start charging control of the regenerative brake power with a relatively low response, such as when there is no other power-carrying vehicle that absorbs the regenerative brake power, the charge / discharge current IS Although the regenerative brake can be continued by the charging control by turning on / off the switching element 111 based on the load / regenerative current IL flowing through the inverter 105, the charging control of the regenerative brake power is performed at a high speed when, for example, an overhead wire break occurs. When it is necessary to start the operation, the information on the DC voltage V_dc of the inverter 105 that can instantaneously detect the instantaneous interruption of the overhead wire cannot be obtained, and there is a problem that it is difficult to continue the regenerative braking reliably.

  An object of the present invention is to charge a power storage device that instantaneously absorbs regenerative power based on the rate of change in the voltage detection value of the inverter DC section when the current path from the current collector to the power line is interrupted during regenerative braking. It is an object of the present invention to provide an environment-friendly railcar drive system that starts control and continuously allows regenerative power to be absorbed by a power storage device.

The railway vehicle drive system of the present invention includes a current collecting means for obtaining power from a power line, inverter means for converting DC power based on the power line power to AC power, a capacitor disposed on the DC side of the inverter means, An electric motor driven by the inverter means, a power storage means capable of charging / discharging power, a switch means for adjusting and controlling a current flowing between the DC side of the inverter means and the power storage means, and a voltage of the capacitor And means for detecting
When the instantaneous interruption of the current path from the current collecting means to the power line is detected based on the change rate of the voltage detection value of the capacitor, the switch means selectively controls the increase rate and the recovery rate of the conduction current. Instantaneous power absorption control in which current is passed from the DC side of the inverter means to the power storage means side and regenerative power generated by the electric motor is charged by the power storage means, and after the completion of the instantaneous power absorption control Regenerative power absorption control based on the detected value of the energization current is performed .

  According to the present invention, when the current path from the current collector to the power line during regenerative braking is interrupted, charging that instantaneously absorbs regenerative power with the power storage device based on the rate of change in the voltage detection value of the inverter DC unit It is possible to provide an environment-friendly driving system for a railway vehicle that can start control and can continuously absorb regenerative power by the power storage device.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a diagram showing an apparatus configuration of an embodiment of an electric vehicle drive system according to the present invention.

  The direct current fed from the current collector 1 is input to the inverter device 4 after the fluctuation in the high frequency region is removed by an LC circuit (filter circuit) constituted by the filter reactor 2 and the filter capacitor 3. The inverter device 4 converts the input DC power into three-phase AC power having a variable voltage variable frequency (VVVF), and drives the main motors 5a and 5b. Although the case where two main motors are driven by the inverter device 4 is shown here, the number of main motors driven by the inverter device 4 is not limited. The voltage sensor 6 a detects the DC voltage V_dc across the filter capacitor 3. Current sensors 7a, 7b and 7c detect the current flowing through the three-phase AC power line between inverter device 4 and main motors 5a and 5b for each phase, and input the detected current to the inverter device. The ground point 100 determines the reference potential of this circuit. The switching elements 8 a and 8 b are arranged in series between the high potential side and the low potential side in the DC power unit between the current collector 1 and the grounding point 200 and the inverter device 4. The voltage sensor 6b is disposed between the electric power of the smoothing reactor 11 and the current sensor 7d, and detects a terminal voltage V_btr of the power storage device 12 described later. The voltage sensor 6b is arranged between the power lines of the smoothing reactor 11 and the current sensor 7d. However, even if this is arranged between the power line of the power storage device 12 and the smoothing reactor 11, the voltage V_btr between the terminals of the power storage device 12 is detected. it can.

  The control device 10 receives the regenerative power P_inv of the inverter device 4, the voltage detection value V_dc of the voltage sensor 6a, the voltage detection value V_btr of the voltage sensor 6b, and the current detection value I_btr of the current sensor 7d, and performs switching to the gate amplifiers 9a and 9b. Gate pulse signals GP1 and GP2 for commanding on / off of the elements 8a and 8b are output. The gate amplifiers 9a and 9b receive the gate pulse signals GP1 and GP2 and convert the switching elements 8a and 8b into voltage control signals that can be turned on / off based on the gate pulse signals GP1 and GP2, thereby controlling the switching elements 8a and 8b on / off. . Voltage sensor 6b detects a voltage between terminals of power storage device 12, which will be described later. The current sensor 7d detects a current that is input to and output from the power storage device 12 described later.

  As the power storage device 12, when priority is given to absorption at the time of instantaneous interruption of the overhead wire, application of an electric double layer capacitor device having high performance charge / discharge input / output characteristics per unit area can be considered. However, since it is important to ensure system redundancy in railway vehicles, there may be a demand to realize self-running to a safe retreat location even in a power outage. For this reason, it can be said that it is appropriate to use a lithium ion battery or the like having a high power storage capacity per unit area.

  The charge / discharge control of the power storage device 12 is realized by periodically turning on / off the switching element 8a or 8b. In this charge / discharge control, the smoothing reactor 11 has a force to keep the rate of change of the current flowing through the power storage device 12 within a predetermined value.

  First, control for discharging the electric power of the power storage device 12 by periodically turning on / off the switching element 8b will be described.

  When the aforementioned switching element 8b is turned on for a predetermined time Ton_b, the output terminals of the power storage device 12 are short-circuited, but the smoothing reactor 11 keeps the current increase rate within a certain value and at the same time the current passed during the Ton_b period. Then, the power energy obtained by time-integrating the product of the terminal voltages of the power storage device 12 is stored. After that, when the switching element 8b is turned off for a predetermined time Toft_b, the power energy stored in the smoothing reactor 11 on the DC power unit side passes through the diode part of the switching element 8a and the current collector 1 and the ground point 100. It is discharged to the DC power unit side between the inverter devices 4. At this time, the voltage value V_dc obtained on the DC power side is determined from the ratio of the time Ton_b to turn on the switching element 8b and the time Toft_b to turn off based on the terminal voltage V_btr of the power storage device 12 by the following equation.

V_dc = V_btr × ((Ton_b + Toft_b) / Toft_b) Equation 2
Next, control for charging power to the power storage device 12 by periodically turning on / off the switching element 8a will be described.

  When the aforementioned switching element 8a is turned on for a predetermined time Ton_a, the DC power unit between the grounding point 100 and the inverter device 4 of the current collector 1 and the grounding point 100 and the inverter device 4 described above. When the potential V_dc with respect to the ground point 100 is higher than the inter-terminal voltage of the power storage device 12 (potential with respect to the ground point 100) V_dc (V_dc> V_bc), a current flows from the DC power unit toward the power storage device 12. At this time, the smoothing reactor 11 stores the power energy obtained by time-integrating the product of the current passed during the Ton_a period and the terminal voltage of the power storage device 12 at the same time while keeping the current increase rate within a certain value. When the switching element 8a is turned off only for a predetermined time Toft_a, the power energy stored in the smoothing reactor 11 on the DC power unit side is discharged from the high potential side terminal of the power storage device 12 to the low potential side terminal, and the diode of the switching element 8b The circuit of the circuit which returns to the smoothing reactor 11 through this part is comprised. That is, the discharge current attenuates as the power energy stored in the smoothing reactor 11 is released during a period in which the switching element 8a is off for a predetermined time Toft_a. At this time, the inter-terminal voltage value V_btr obtained by the power storage device 12 is determined from the p ratio of the time Ton_a for turning on the switching element 8a and the time Toft_a for turning off, based on the DC power side V_dc.

V_btr = V_dc x (Ton_a / (Ton_a + Toft_a))
With the above configuration, the time variation rate dV_dc / dt of the DC voltage detection value V_dc of the voltage sensor 6a is calculated by the control device 10, and when dv_dc / dt exceeds a predetermined value, the current detection value I_btr of the current sensor 7d is The switching elements 8a and 8b can be driven by controlling the gate pulse signals GP1 and GP2 output from the gate amplifiers 9a and 9b so as to follow a predetermined charging current command value I_abs_cmb (not shown).

  Further, a charging current command value I_regen_cmb (not shown) that can be charged to the power storage device 12 is calculated by the control device 10 from the regenerative power P_regen of the inverter device 4 and the inter-terminal voltage V_btr of the power storage device 12, and the current sensor 7d The switching elements 8a and 8b can be driven by controlling the gate pulse signals GP1 and GP2 output from the gate amplifiers 9a and 9b so that the current detection value I_btr follows the charging current command value I_regen_cmb.

  As a result, when the current path from the current collector to the power line during regenerative braking is interrupted, charging control that instantly absorbs regenerative power with the power storage device is started based on the rate of change in the voltage detection value of the inverter DC section. In addition, a drive system for an electric vehicle that can continuously absorb regenerative power by the power storage device can be realized.

  FIG. 2 is a block diagram showing a control method in an embodiment of the electric vehicle drive system of the present invention.

  The voltage detection value V_dc of the voltage sensor 6a is input to the change rate calculation unit 51, and the change amount dV_dc / dt of the voltage V_dc within a predetermined period (dt) is calculated.

  The comparator 52a receives dV_dc / dt calculated by the change rate calculation unit and outputs an overhead wire interruption detection flag flg_i_up which is a command for selecting an increase rate and a recovery rate of the charging current at the time of the interruption of the overhead wire. The comparator 52a sets the initial output value “flg_i_up = 0” and outputs “flg_i_up = 1” while the dV_dc / dt value is equal to or higher than the instantaneous overhead wire detection level dV_on. To do. Also. When the output value “flg_i_up = 1” is output and the value of dV_dc / dt becomes less than the overhead wire breakage detection level dV_on, “flg_i_up = 0” is output. The selector 53a selects the charging current increase rate ΔI_up (positive value) or the charging current recovery rate ΔI_down (negative value) in accordance with the overhead wire break detection flag flg_i_up output from the comparator 52a, and sets it as the charging current command value ΔI_a. Output. That is, in the state of “flg_i_up = 1” in which the voltage change rate dV_dc / dt is equal to or higher than the instantaneous voltage break detection on-level dV_on, and the state continues “flg_i_up = 1” It is equal to the current increase rate ΔI_up. In addition, in the state of “flg_i_up = 0” where the voltage change rate dV_dc / dt is less than the instantaneous overhead wire break detection level dV_on and the state continues, the output of the selector 53a is equal to the charging current recovery rate ΔI_down.

  The ethics circuit 54 receives the overhead wire break detection flag flg_i_up output from the comparator 52a and the flg_i_zero output from the comparator 52b described later. The logical sum operation result of flg_i_up and flg_i_zero and flg_i_sum for controlling the integral operation of the charging current increase rate or recovery rate are output. Further, the selector 53 b selects zero output or the charging current change amount ΔI_a according to the output flg_i_sum of the OR circuit 54 and inputs it to the integrator 55. The comparator 52b receives the absorption current command value I_abs_cmb which is the output result of the comparator 55, outputs “flg_i_zero = 0” when I_abs_cmb is less than or equal to zero, and outputs “flg_i_zero = 1” when I_abs_cmd is greater than zero. .

  As a result, the logical sum circuit 54 that inputs flg_i_zero and flg_i_up has a dV_dc / dt that exceeds the overhead wire break detection on-level dV_on and continues that state (that is, when flg_i_up = 1). When the output I_abs_cmb of 55 is larger than zero (that is, when flg_i_zero = 1), “flg_i_sum = 1” is output. At this time, the selector 53b selects the charging current change amount ΔI_a as an output, but in the state of “flg_i_up = 1” due to the action of the selector 53a, the charging increase rate ΔI_a (addition value) is obtained, and “flg_i_up = 0” In the state, it becomes equal to the charge recovery rate ΔI_down (negative value). That is, the addition / subtraction of the output of the integrator 55 is controlled by flg_i_sum and flg_i_up. When “flg_i_up = 1”, the output of the OR circuit 54 is “flg_i_sum = 1”, and the integrator 55 integrates ΔI_up (positive value), so that I_abs_cmb is integrated to a value larger than zero. At this time, the comparator 52b outputs “flg_i_zero = 1” because I_abs_cmb is larger than zero. After that, when “flg_i_up = 0”, the output of the OR circuit 54 is “flg_i_zero = 1”, so that “flg_i_sum = 1” continues. However, since the integrator 55 integrates ΔI_down (negative value), i_abs_cmb Is subtracted. When zero is reached by subtraction of I_abs_cmb, the output of the comparator 52b is “flg_i_zero = 0”, and the output of the OR circuit 54 is “flg_i_sum = 0”. That is, since the output of the selector 53b becomes zero, I_abs_cmb, which is the output of the integrator 55, continues to have a zero value when it reaches zero.

  The low-order selector 56a selects the smaller one of the absorption current command value I_abs_cmb which is the output of the integrator 55 and the maximum charging current (instantaneous value) Imax_btr_ins allowed by the power storage device 12, and sets the limited absorption current command value I_abs_cmb_lmt. Output.

  On the other hand, the flip-flop circuit 102 is a reset priority flip-flop that receives the signal obtained by inverting the brake flag B_flg from the driver's cab with the ethical inverter 103 as a set input, which is an output of the comparator 52a. After the instantaneous interruption of the overhead wire, the storage regeneration valid flag flg_regen for storing the inverter regeneration power in the power storage device 12 is output. That is, in the state of “B_flg = 0”, the reset input of the flip-flop circuit 102 is “1”. Therefore, even if the overhead wire break detection flag flg_i_up is “flg_i_up = 1”, the storage regeneration valid flag flg_regen is not set, = 0 ”. When the state of “B_flg = 1” is set by the brake operation of the cab, the reset input of the flip-flop circuit 102 is “0”, and when the overhead wire break detection flag flg_i_up becomes “flg_i_up = 1”, the power regeneration The valid flag flg_regen is set to “flg_regen = 1”. The multiplier 58 and the divider 59 divide the power storage device voltage I_btr from the inverter regenerative power P_regen to calculate a regenerative current I_regen_0. The selector 53c outputs a regenerative current command I_regen_cmd according to the overhead wire break detection flag flg_i_up, which is the output of the flip-flop circuit 102. That is, when “flg_i_up = 0”, the regenerative current command I_regen_cmd is zero, and when “flg_i_up = 0”, the regenerative current command I_regen_cmd is equal to the above-described regenerative current I_regen_0.

I_regen_cmd = 0 when flg_i_up = 0
When flg_i_up = 1, I_regen_cmd = I_regen_0 (= P_regen / V_btr)
The low order selector 56b is the output of the selector 53c. A smaller value is selected from the regenerative current command I_regen_cmd and the maximum charging current (rated value) Imax_btr_rat allowed by the power storage device 12, and a smaller value is selected from the limited regenerative current command value I_abs_cmd_lmt and the limited regenerative current command value I_regen_cmd_lmt. Select to output the continuous regenerative current command value I_brfree_cmd.

  The subtractor 60 subtracts the power storage device current I_btr from the continuous regenerative current command value I_brfree_cmd, and outputs a continuous regenerative control command ΔI_bfree_cmd. The stabilization controller 62 receives the continuous regenerative control command ΔI_brfree_cmd and outputs a continuous regenerative control operation amount Duty_brfree_man for quickly matching the difference between the above-described continuous regenerative current command value I_brfree_cmd and the power storage device current I_btr. The low level selector 56c and the high level selector 57b determine the lower limit value and the upper limit value of the continuous regeneration operation amount Duty_brfree_man. First, the high level selector 57b selects and outputs a large value of the continuous regeneration control manipulated variable Duty_brfree_man and zero, and the low level selector 56c selects and outputs the output value of the high level selector 57b and one of the smaller values. To do. That is, the continuous regeneration control operation amount Duty_brfree_man is limited to a range from 0 to 1 by the low-order selector 57b, and the limited continuous regeneration control operation amount Duty_brfree_man_lmt is output. The gate pulse calculation unit 61 outputs a step-down chopper gate pulse GP_buck that controls on / off of the switching element 8b based on the limited continuous regenerative operation amount Duty_brfree_man_lmt.

  With the above configuration, the time change rate dV_dc / dt of the DC voltage detection value V_dc of the voltage sensor 6a is calculated by the control device 10, and when dV_dc / dt is exceeded, the current detection value I_btr of the current sensor 7d is set to a predetermined value. The switching elements 8a and 8b can be driven by controlling the gate pulse signals GP1 and GP2 which are the outputs of the gate amplifiers 9a and 9b so as to follow the charging current command value I_abs_cmd.

  Further, the control device 10 calculates a charge command value I_regen_cmd (not shown) that can charge the power storage device 12 from the regenerative power P_regen of the inverter device 4 and the inter-terminal voltage V_btr of the power storage device 12, and the current sensor 7d The switching elements 8a and 8b can be driven by controlling the gate pulse signals GP1 and GP2 which are the outputs of the gate amplifiers 9a and 9b so that the detected current value I_btr follows the charging current command value I_regen_cmd described above.

  As a result, when the current path from the current collector to the power line is interrupted during regenerative braking, charging control that instantly absorbs regenerative power with the power storage device is started based on the rate of change in the detected voltage value of the inverter DC section. In addition, it is possible to realize an electric vehicle drive system that can continuously absorb regenerative power by the power storage device.

  FIG. 3 is a waveform diagram showing a control operation in an embodiment of the electric vehicle drive system of the present invention.

In FIG. 3, the horizontal axis represents elapsed time, and the vertical axis represents the magnitude of each signal.
First, at time t0, the brake plug B_flg is turned on by operating the cab. As a result, the DC part regenerative electric power P_brk rises, so that deceleration starts and the rotor frequency Fr decreases. Assuming that the brake command from the cab is the same, the DC regenerative power P_brk is maximized in a region where the modulation rate of VVVF control is 100% (maximum voltage) and the current characteristics of the motor are not saturated. FIG. 3 shows a state in which the DC portion regenerative power P_brk is maximum between time t1 and t4 (rotor frequency Fr1 to Fr4).

  At normal times, the DC portion regenerative power P_brk generated by the regenerative brake is returned from the current collector 1 to the overhead line so that the vehicle traveling around uses it as power running power. However, if there is an instantaneous interruption of the overhead line that separates the overhead line from the current collector 1 for a very short time, the DC part regenerative power P_brk cannot be absorbed, so the voltage of the DC part rises instantaneously and the regenerative brake is disabled due to the overvoltage protection operation. Occurs. The main object of the present invention is to prevent the regenerative invalidation at the time of the instantaneous interruption of the overhead wire.

  Consider a case where an overhead wire break occurs at time t2 that is intermediate between time t1 and time t4 when the DC unit regenerative power P_brk is maximum, and is restored to t3 after a very short time. The overhead line voltage detection value Es normally indicates that the current collector is in contact with the overhead line, and therefore the voltage value indicates the actual overhead line voltage Es0. The overhead line voltage detection value Es instantaneously becomes zero at the time t2 when the instantaneous interruption occurs, and returns to the original voltage value Es0 again at the time t3 when the interruption is resolved.

  When the overhead wire break occurs, the DC regenerative power P_brk cannot be returned from the current collector 1 to the overhead wire, and the power is charged in the filter capacitor 3. In combination with the filter reactor 2, the filter capacitor 3 serves as a filter circuit that removes the ripple of the overhead wire current. For this reason, the time constant is often set to about 10 ms. On the other hand, the filter reactor 2 also has a function of suppressing the current change rate to a predetermined value in order to protect the substation equipment when an overhead wire short circuit accident occurs. Therefore, the capacitance of the filter capacitor 3 and the inductance value of the filter reactor 2 are in a trade-off relationship, and the capacitance C of the filter capacitor 3 is often about 0.01 (F) in many cases. For example, when the DC regenerative power P_brk = 500kW and Ecf = 1500V, the rate of change of the filter capacitor voltage change rate at the time of instantaneous interruption of the overhead line is dEcf / dt = (P_brk / Ecf) / C = (500 * 1000/1500) /0.01=33333 (V / s). That is, under this assumption, the filter capacitor voltage rises by 33 kV per second when the overhead wire is interrupted.

  Thus, paying attention to the fact that the filter capacitor voltage Ecf, that is, the DC part voltage V_dc rapidly increases when the overhead wire break occurs, when the rate of change dV_dc / dt of the DC part voltage detection value V_dc exceeds a predetermined value, “Instantaneous power absorption control” is performed by determining that an instantaneous interruption of the overhead line has occurred and turning on the instantaneous interruption detection flag flg_itr.

  In “instantaneous power absorption control”, during the period when the instantaneous interruption detection flag flg_itr is on, the step-down chopper manipulated variable I_abs_cmd is increased, and the charging current from the DC unit to the power storage device 12 is allowed to flow instantaneously. As a result, the increase in the filter capacitor voltage Ecf is minimized, and the filter capacitor voltage change rate Ecf decreases. When the filter capacitor voltage change rate Ecf decreases below the predetermined value, the instantaneous interruption detection flag flg_itr is turned off, the step-down chopper manipulated variable I_abs_cmd is reduced to zero, and the instantaneous power absorption control is completed.

  On the other hand, even after the instantaneous power absorption control is completed, the cause of the occurrence of instantaneous overhead wire breakage is not always solved. For this reason, after completion of the instantaneous power absorption control, the process shifts to “regenerative power absorption control” to continue the regenerative braking. In “regenerative power absorption control”, the direct current regenerative power P_brk is just charged to the power storage device 12. The step-down chopper control manipulated variable I_regen_cmd is calculated. By controlling the switching element 8a based on this, the regenerative electric power during the period when the brake flag B_flg is kept on is charged to the power storage device 12 without returning from the power collecting device 1 to the overhead wire. Realizes stable continuous regenerative braking that is not affected by instantaneous interruptions.

  As described above, according to the configuration of the present invention, when the current path from the current collector to the power line is interrupted during regenerative braking, the regenerative power is instantaneously generated based on the rate of change in the voltage detection value of the inverter DC unit. It is possible to realize a drive system for an electric vehicle that starts charging control that is absorbed by the power storage device and that can continuously absorb regenerative power by the power storage device.

  FIG. 4 is a diagram showing a device configuration of the second embodiment in the electric vehicle drive system of the present invention.

  The DC power fed from the current collector 1 is input to the inverter device 4 after the fluctuation in the high frequency region is removed by the LC filtering circuit constituted by the filter reactor 2 and the filter capacitor 3. The inverter device 4 converts the input DC power into three-phase AC power having a variable voltage variable frequency (VVVF), and drives the main motors 5a and 5b. Although the case where two main motors are driven by the inverter device 4 is shown here, the number of main motors driven by the inverter device 4 is not limited. The voltage sensor 6 a detects the DC voltage V_dc across the filter capacitor 3. Current sensors 7a, 7b, and 7c detect the current flowing through the inverter device 4 and the three-phase AC power line between the main motors 5a and 5b for each phase, and input to the inverter device 4. The ground point 100 determines the reference potential of this circuit. The switching elements 8 a and 8 b are arranged in series between the high voltage side and the low voltage side in the DC power unit between the current collector 1 and the ground point 100 and the inverter device 4. The switching element 8c is arranged in series with the brake resistor 13 between the high potential side and the low potential side of the DC power unit between the current collector 1 and the grounding point 100 and the inverter device 4 described above. . The voltage sensor 6b is disposed between the power lines of the smoothing reactor 11 and the current sensor 7d, and detects a terminal voltage V_btr of the power storage device 12 described later. The voltage sensor 6b is arranged between the power line of the smoothing reactor 11 and the current sensor 7d. However, even if it is arranged between the power line of the power storage device 12 and the smoothing reactor 11, the voltage V_btr between the terminals of the power storage device 12 is set. It can be detected.

  The control device 10 receives the regenerative power P_inv of the inverter device 4, the voltage detection value V_dc of the voltage sensor 6a, the voltage detection value V_btr of the voltage sensor 6b, and the current detection value I_btr of the current sensor 7d, and inputs to the gate amplifiers 9a, 9b and 9c. Gate pulse signals GP1, GP2, GP3 for commanding on / off of the switching elements 8a, 8b, 8c are output. The gate amplifiers 9a, 9b, and 9c receive the gate pulse signals GP1, GP2, and GP3 as input, and switch the switching elements 8a, 8b, and 8c to voltage control signals that can be turned on / off based on the gate pulse signals GP1, GP2, and GP3. , 8c are controlled on / off. Voltage sensor 6b detects a voltage between terminals of power storage device 12, which will be described later. The current sensor 7d detects a current that is input to and output from the power storage device 12 described later.

  As the power storage device 12, when priority is given to instantaneous absorption of regenerative power at the time of instantaneous interruption of an overhead wire, application of an electric double layer capacitor device having high-performance charge / discharge input / output characteristics per unit volume can be considered. However, since it is important to ensure system redundancy in a railway vehicle, there may be a demand for realizing self-running to a safe retreat location even in a power failure state. For this reason, it can be said that it is appropriate to use a lithium ion battery or the like having a high storage capacity per unit volume.

  The charge / discharge control of the power storage device 12 is realized by periodically turning on / off the switching element 8a or 8b. In this charge / discharge control, the smoothing reactor 11 has a function of suppressing the rate of change of the current flowing through the power storage device 12 within a predetermined value.

  First, control for discharging the power storage device 12 by turning on / off the switching element 8b will be described.

  When the above-described switching element 8b is turned on for a predetermined time Ton_b, the output terminals of the power storage device 12 are short-circuited. However, the smoothing reactor 11 suppresses the current increase rate within a certain value and simultaneously passes through the period of Ton_b. The power energy obtained by time-integrating the product of the flowing current and the terminal voltage of the power storage device 12 is stored. After that, when the switching element 8b is turned off for a predetermined time Toff_b, the power energy stored in the smoothing reactor 11 on the DC power unit side passes through the diode part of the switching element 8a and the current collector 1 and the grounding point 100 described above. It is discharged to the DC power unit side between the inverter devices 4. At this time, the voltage value V_dc obtained on the DC power side is determined from the ratio of the time Ton_b for turning on the switching element 8b and the time Toff_b for turning off based on the terminal voltage V_btr of the power storage device 12 by the following equation.

V_dc = V_btr × ((Ton_b + Toff_b) / Toff_b) Equation 2
Next, control for charging the power to the power storage device 12 by turning on / off the switching element 8b will be described.

  When the aforementioned switching element 8b is turned on for a predetermined time Ton_a, the potential V_dc of the DC power unit between the current collector 1 and the ground point 100 and the inverter device 4 with respect to the ground point 100 is between the terminals of the power storage device 12. When the voltage (potential with respect to the grounding point 100) is higher than V_bc (V_dc> V_bc), a current flows from the DC power unit toward the power storage device 12. At this time, the smoothing reactor 11 stores the energy obtained by time-integrating the product of the current passed during the Ton_a period and the terminal voltage of the power storage device 12 while keeping the current increase rate within a certain value. Thereafter, when the switching element 8b is turned off for a predetermined time Toff_a, the power energy stored in the smoothing reactor 11 on the DC power unit side is released from the high potential side terminal of the power storage device 12 to the low potential side terminal, and the switching element 8b A circuit that returns to the smoothing reactor 11 through the diode portion is formed. That is, during a period in which the switching element 8a is turned off for a predetermined time Toff_a, the electric energy stored in the smoothing reactor 11 continues to flow into the power storage device 12, and the electric energy stored in the smoothing reactor 11 is released. Accordingly, the charging current decays. At this time, the inter-terminal voltage value V_btr obtained in the power storage device 12 is determined from the ratio of the time Ton_a for turning on the switching element 8a and the time Toff_a for turning off based on the DC power side V_dc by the following equation.

V_btr = V_dc × (Ton_a / (Ton_a + Toff_a)) Equation 3
Further, control (brake chopper control) for instantaneously converting the electric power of the direct current portion from the brake resistor 13 to heat energy by turning on / off the switching element 8c will be described.

  When the aforementioned switching element 8c is turned on for a predetermined time Ton_c, the current collector 1 and the DC power unit between the grounding point 100 and the inverter device 4 are connected via the brake resistor 13 during that period. Therefore, when the ON / OFF of the switching element 8 c is appropriately controlled during the regenerative braking operation of the inverter device 4, part or all of the inverter regenerative power can be consumed by the brake resistor 13. It is discharged to the DC power unit side between the current collector 1 and the grounding point 100 and the inverter device 4. At this time, the conduction current I_brr of the brake resistor 13 is determined from the ratio of the time Ton_c to turn on the switching element 8b and the time Toff_c to turn off based on the regenerative brake current I_inv_regen as follows.

I_r_brk = I_inv_regen × (Ton_c / (Ton_c + Toff_c)) Equation 4
With the above configuration, the time change rate dV_dc / dt of the DC voltage detector V_dc of the voltage sensor 6b is calculated by the control device 10, and when dV_dc / dt exceeds a predetermined value, the current detector I_brr of the current sensor 7e is The switching element 8c can be driven by controlling the gate pulse signal GP3, which is the output of the gate amplifier 9c, so as to follow a predetermined charging current command value I_abs_cmd (not shown).

  Further, a charging current command value I_regen_cmd (not shown) that can charge the power storage device 12 is calculated by the control device 10 from the regenerative power P_inv of the inverter device 4 and the inter-terminal voltage V_btr of the power storage device 12, and the current sensor 7d. Thus, the switching elements 8a and 9b can be driven by controlling the gate pulse signals GP1 and GP2 which are the outputs of the gate amplifiers 9a and 9b so that the current detector I_btr of the current follows the charging current command value I_regen_cmd_b.

  As a result, when the current path from the current collector to the power line is interrupted during regenerative braking, charging control that instantly absorbs regenerative power with the power storage device based on the rate of change in the voltage detection value of the inverter DC section is started. In addition, a drive system for an electric vehicle that can continuously absorb regenerative power by the power storage device can be realized.

  FIG. 5 is a block diagram showing a control method of the second embodiment of the electric vehicle drive system of the present invention.

  The DC part voltage detection value V_dc of the voltage sensor 6a is input to the change rate calculator 51, and the change amount ΔV_dc / Δt of the DC part voltage V_dc within a predetermined period (dt) is calculated. The comparator 52a receives dV_dc / dt calculated by the change rate calculation unit and outputs an overhead wire breakage detection flag flg_i_up which is a command for selecting an increase rate and a recovery rate of the charging current at the time of the wire breakage. The comparator 52a outputs “flg_i_up = 1” while the initial output value “flg_i_up = 0” is maintained when the value of dV_dc / dt is equal to or higher than the instantaneous disconnection detection level dV_on. To do. Further, when the output value “flg_i_up = 1” is output and the value of dV_dc / dt becomes less than the overhead wire breakage detection level dV_on, “flg_i_up = 0” is output. The selector 53a selects the charging current increase rate ΔI_up (positive value) or the charging current recovery rate ΔI_down (negative value) according to the overhead wire break detection flag flg_i_up output from the comparator 52a, and the charging current command value Output as ΔI_a. In other words, in the state of “flg_i_up = 1” where the voltage change rate dV_dc / dt is equal to or higher than the instantaneous voltage interruption detection on-level dV_on and the state continues, the charging current change rate ΔI_a that is the output of the selector 53a is In the state of “flg_i_up = 0” in which the voltage change rate dV_dc / dt is equal to the current increase rate ΔI_up and the voltage change rate dV_dc / dt is less than the overhead wire breakage detection level dV_on and continues that state, the output of the selector 53a is the charging current recovery rate ΔI_down be equivalent to. The OR circuit 54 receives the overhead wire break detection flag flg_i_up output from the comparator 52a and flg_i_zero, which is output from the comparator 52b described later, as an operation result of the OR of flg_i_up and flg_i_zero. Outputs flg_i_sum that controls the integration of the recovery rate. Further, the selector 53 b selects zero output or the charging current change amount ΔI_a according to the output flg_i_sum of the OR circuit 54 and inputs it to the integrator 55. The comparator 52b receives the absorption current command value I_abs_cmd, which is the output result of the integrator 55, and outputs “flg_i_zero = 0” when I_abs_cmd is less than or equal to zero, and outputs “flg_i_zero = 1” when i_abs_cmd is greater than zero. .

  As a result, the logical sum circuit 54 that inputs flg_i_zero and flg_i_up continues when dV_dc / dt exceeds the overhead wire break detection on-level dV_on (that is, when flg_i_up = 1), or When the output i_abs_cmd of the integrator 55 is greater than zero (that is, when flg_i_zero = 1), “flg_i_sum = 1” is output. At this time, the selector 53b selects the charging current change amount ΔI_a as an output, but in the state of “flg_i_up = 1” by the action of the selector 53a, the charging current increase rate ΔI_up (addition value) and “flg_i_up = 0” In the state of “”, the charging current recovery rate ΔI_down (negative value) is equal. That is, the addition / subtraction of the output of the integrator 55 is controlled by flg_i_sum and flg_i_up. When “flg_i_up = 1”, the output of the OR circuit 54 is “flg_i_sum = 1”, and the integrator 55 integrates Δ_up (positive value), so that I_abs_cmd is integrated to a value larger than zero. At this time, the comparator 52b outputs “flg_i_zero = 1” because I_abs_cmd is larger than zero. After that, when “flg_i_up = 0”, the output of the OR circuit 54 is “flg_i_zero = 1”, so that “flg_i_sum = 1” continues. However, since the integrator 55 integrates ΔI_down (negative value), i_abs_cmd Is subtracted. When it reaches zero by subtraction of I_abs_cmd, the output of the comparator 52b becomes “flg_i_zero = 0”, and the output of the OR circuit 54 becomes “flg_i_sum = 0”. That is, since the output of the selector 53b becomes zero, I_abs_cmd, which is the output of the integrator 55, continues to have a zero value when reaching the example. The low-order selector 56a selects the smaller one of the suction current command value I_abs_cmd that is the output of the integrator 55 and the maximum charging current (instantaneous value) Imax_btr_ins allowed by the power storage device 12, and the limited absorption current command value I_abs_lmt Is output.

  The reducer 60a subtracts the brake resistor current I_btr from the continuous regenerative current command value I_abs_lmt, and outputs a continuous regenerative control command ΔI_brfree_cmd_a. The stabilization controller 62a receives the continuous regeneration control command ΔI_brfree_cmd_a as an input, and outputs a continuous regeneration control manipulated variable Duty_brfree_man_a for quickly matching the difference between the above-described continuous regeneration current command value I_brfree_cmd_a and the brake resistor current I_brr. The low level selector 56c and the high level selector 57b determine the lower limit value and the upper limit value of the continuous regeneration control manipulated variable Duty_brfree_man_a. First, the high level selector 57b selects and outputs a continuous regeneration control manipulated variable Duty_brfree_man_a and a large value of zero, and the low level selector 56c selects an output value of the high level selector 57b and a small value of one. Output. That is, the range of the continuous regeneration control operation amount Duty_brfree_man_a is limited from 0 to 1 by the low level selector 56c and the high level selector 57b, and the limited continuous regeneration control operation amount Duty_brfree_man_a_lmt is output. The gate pulse calculation unit 61a controls on / off of the switching element 8a based on the limited continuous regeneration control operation amount Duty_brfree_man_a_lmt. Outputs step-down chopper gate pulse GP_bch.

  On the other hand, the flip-flop circuit 102 is a reset-priority flip-flop that inputs the signal obtained by inverting the brake flag B_flg from the cab with the logic inverter 103 as a set input, which is the output of the comparator 52a. Yes, after the occurrence of the instantaneous interruption of the overhead wire, a power regeneration valid flag flg_regen for storing the inverter regenerative power in the power storage device 12 is output. That is, in the state of “B_flg = 0”, the reset input of the flip-flop circuit 102 is “1”. Therefore, even if the overhead wire break detection flag flg_i_up is “flg_i_up = 1”, the storage regeneration valid flag flg_regen is not set, = 0 ”. When the state of “B_flg = 1” is set by the brake operation of the cab, the reset input of the flip-flop circuit 102 is “0”, and when the overhead wire break detection flag flg_i_up becomes “flg_i_up = 1”, the power regeneration The valid flag flg_regen is set to “flg_regen = 1”. The multiplier 58 and the divider 59 divide the power storage device voltage I_btr from the inverter regenerative power P_regen to calculate a regenerative current I_regen_0. The selector 53c outputs a regenerative current command I_regen_cmd according to the overhead wire break detection flag flg_i_up, which is the output of the flip-flop circuit 102. That is, when “flg_i_up = 0”, the regenerative current command I_regen_cmd is zero, and when “flg_i_up = 1”, the regenerative current command I_regen_cmd is equal to the above-described regenerative current I_regen_0.

I_regen_cmd = 0 when flg_i_up = 0
When flg_i_up = 1, I_regen_cmd = I_regen_0 (= P_regen / V_btr)
The low-order selector 56b selects a smaller value from the regenerative current command I_regen_cmd, which is the output of the selector 53c, and the maximum charging current (rated value) Imax_btr_rat allowed by the power storage device 12, and outputs a limited regenerative current command I_regen_cmd_lmt To do. The high level selector 57a selects a smaller value from the limited absorption current command value I_abs_cmd_lmt and the limited regenerative current command value I_regen_cmd_lmt, and outputs the continuous regenerative current command value I_brfree_cmd.

  The subtractor 60b subtracts the power storage device current I_btr from the continuous regenerative current command value I_brfree_cmd_b and outputs a continuous regenerative control command ΔI_brfree_cmd_b. The stabilization controller 2b receives the continuous regenerative control command ΔI_brfree_cmd_b and outputs a continuous regenerative control operation amount Duty_brfree_man_b for quickly matching the difference between the above-described continuous regenerative current command value I_brfree_cmd_b and the power storage device current I_btr. The low level selector 56d and the high level selector 57c determine the lower limit value and the upper limit value of the continuous regeneration control manipulated variable Duty_brfree_man_b. First, the high level selector 57b selects and outputs a continuous regeneration control manipulated variable Duty_brfree_man_b and a larger value of zero, and the low level selector 56d selects an output value of the high level selector 57c and a smaller value of one. Output. That is, the range of the continuous regeneration control operation amount Duty_brfree_man_b is limited to 0 to 1 by the low level selector 56d and the high level selector 57c, and the limited continuous regeneration control operation amount Duty_brfree_man_lmt is output. The gate pulse calculation unit 61b outputs a step-down chopper gate pulse GP_buck that controls on / off of the switching element 8b based on the limited continuous regeneration control operation amount Duty_brfree_man_lmt.

  With the above configuration, the time change rate dV_dc / dt of the DC voltage detection value V_dc of the voltage sensor 6b is calculated by the control device 10, and when dV_dc / dt exceeds a predetermined value, the current detection value I_brr of the current sensor 7e is calculated. The switching element 8c can be driven by controlling the gate pulse signal GP3, which is the output of the gate amplifier 9c, so as to follow a predetermined charging current command value I_abs_cmd.

  Further, the control device 10 calculates a charging current command value I_regen_cmd that can be charged to the power storage device 12 from the regenerative power P_inv of the inverter device 4 and the inter-terminal voltage V_btr of the power storage device 12, and the current detection value I_btr of the current sensor 7d is calculated. The switching elements 8a and 8b can be driven by controlling the gate pulse signals GP1 and GP2 which are the outputs of the gate amplifiers 9a and 9b so as to follow the above-described charging current command value I_regen_cmd_b.

  As a result, when the current path from the current collector to the power line is interrupted during regenerative braking, charging control that instantly absorbs regenerative power with the power storage device based on the rate of change in the voltage detection value of the inverter DC section is started. In addition, a drive system for an electric vehicle that can continuously absorb regenerative power by the power storage device can be realized.

  FIG. 6 is a waveform diagram showing a control operation of the second embodiment of the electric vehicle drive system of the present invention. In FIG. 6, the horizontal axis represents elapsed time, and the vertical axis represents the magnitude of each signal.

  First, at time t0, the brake flag B_flg is turned on by operating the cab. As a result, the DC part regenerative electric power P_brk rises, so that deceleration starts and the rotor frequency Fr decreases. Assuming that the brake force command from the cab is the same, the DC regenerative power P_brk is maximized in a region where the modulation rate of VVVF control is 100% (maximum voltage) and the current characteristics of the motor are not saturated. FIG. 6 shows a state in which the DC regenerative power P_brk is maximum between time t1 and t4 (rotor frequencies Frl to Fr4).

  At normal times, the DC part regenerative power P_brk generated by the regenerative brake is returned to the overhead line from the current collector 1 to be used as power running power by vehicles traveling around. However, if there is an instantaneous interruption of the overhead line that separates the overhead line from the current collector 1 for a very short time, the DC part regenerative power P_brk cannot be absorbed, so the voltage of the DC part rises instantaneously and the regenerative brake is disabled due to the overvoltage protection operation. Occurs. The main object of the present invention is to prevent the regenerative invalidation at the time of the instantaneous interruption of the overhead wire.

  Now, consider a case where an overhead wire break occurs at a time t2 in which the DC part regenerative power P_brk is maximum between t1 and t4, and the power is restored to t3 after a very short time. The overhead line voltage detection value Es normally indicates the actual overhead line voltage Es0 because the current collector is in contact with the overhead line. The overhead line voltage detection value Es instantaneously becomes zero at the time t2 when the instantaneous interruption occurs, and returns to the original voltage Es0 again at the time t3 when the instantaneous interruption is eliminated.

  When the overhead wire break occurs, the DC part regenerative power P_brk cannot be returned from the current collector 1 to the overhead wire, and the power is charged to the filter capacitor 3. In combination with the filter reactor 2, the filter capacitor 3 serves as a filter circuit that removes the ripple of the overhead wire current. For this reason, the time constant is often set to about 10 ms. On the other hand, the filter reactor 2 also has a function of suppressing the current change rate to a predetermined value in order to protect the substation equipment when an overhead wire short circuit accident occurs. Therefore, the capacitance of the filter capacitor 3 and the inductance value of the filter reactor 2 are in a trade-off relationship, and the capacitance C of the filter capacitor 3 is often about 0.01 (F) in many cases. For example, when the DC regenerative power P_brk = 500 kW and Ecf = 1500 V, the rate of change of the filter capacitor voltage change rate when the overhead wire is instantaneously interrupted is dEcf / dt (P_brk / Ecf) / C = (500 * 1000/1500) / 0.1 = 33333 (V / s). That is, under this assumption, the filter capacitor voltage rises by 33 kV per second when the overhead wire is interrupted.

  Thus, paying attention to the fact that the filter capacitor voltage Ecf, that is, the direct-current voltage V_dc rapidly increases when an overhead wire break occurs, when the rate of change dV_dc / dt of the DC voltage detection value V_dc exceeds a predetermined value, “Instantaneous power absorption control” is performed by determining that an instantaneous interruption of the overhead line has occurred and turning on the instantaneous interruption detection flag flg_itr.

  In the “instantaneous power absorption control”, the brake chopper control operation amount I_brfree_cmd_a is increased and the charging current from the DC unit to the power storage device 12 is allowed to flow instantaneously while the instantaneous interruption detection flag flg_itr is on. As a result, the increase in the filter capacitor voltage Ecf is minimized, and the filter capacitor voltage change rate Ecf decreases. When the filter capacitor voltage change rate Ecf decreases below the predetermined value, the instantaneous interruption detection flag flg_itr is turned off, the brake chopper control operation amount I_brfree_cmd_a is reduced to zero, and the instantaneous power absorption control is completed.

  On the other hand, even after the instantaneous power absorption control is completed, the cause of the occurrence of the instantaneous interruption of the overhead line is not necessarily eliminated. For this reason, after the instantaneous power absorption control is completed, the process proceeds to “regenerative power absorption control” and the regenerative braking is continued. In the “regenerative power absorption control”, the step-down chopper control operation amount I_brfee_cmd_b for charging the power storage device 12 with the DC unit regenerative power P_brk is calculated. By controlling the switching element 8a based on this, the regenerative power during the period when the brake flag B_flg is kept on is charged to the power storage device 12 without returning from the current collector 1 to the overhead wire, thereby Realizes stable continuous regenerative braking that is not affected by instantaneous interruption.

  As described above, according to the configuration of the present invention, when the current path from the current collector to the power line is interrupted during regenerative braking, the regenerative power is instantaneously based on the rate of change in the voltage detection value of the inverter DC unit. Is started to be absorbed by the power storage device, and regenerative power can be continuously absorbed by the power storage device. An electric vehicle drive system can be realized.

  FIG. 7 is a diagram showing a device configuration of the third embodiment in the electric vehicle drive system of the present invention.

  The DC power fed from the current collector 1 is input to the inverter device 4 after the fluctuation in the high frequency region is removed by an LC circuit (filter circuit) composed of the filter reactor 2 and the filter capacitor 3. The inverter device 4 converts the input DC power into three-phase DC power having a variable voltage variable frequency (VVVF), and drives the main motors 5a and 5b. Although the case where two main motors are driven by the inverter device 4 is shown here, the number of main motors driven by the inverter device 4 is not limited. The voltage sensor 6 a detects the DC part voltage V_dc across the filter capacitor 3. Current sensors 7a, 7b, and 7c detect the current flowing through the three-phase AC power line between inverter device 4 and main motors 5a and 5b for each phase, and input the detected current to inverter device 4. The ground point 100 determines the reference potential of this circuit. The switching elements 8a and 8b are arranged in series between the high potential side and the low potential side in the DC power unit between the current collector 1 and the ground point 100 and the inverter device 4 described above. The voltage sensor 6b is disposed between the power line of the smoothing reactor 11 and the current sensor 7d, and detects the inter-terminal voltage V_btr of the power storage device 12. The voltage sensor 6b is arranged between the power line of the smoothing reactor 11 and the current sensor 7d. However, even if it is arranged between the power line of the power storage device 12 and the smoothing reactor 11, the voltage between terminals of the power storage device 12 described later is used. V_btr can be detected.

  The control device 10 receives the regenerative power P_inv of the inverter device 4, the voltage detection value V_dc of the voltage sensor 6a, the voltage detection value V_btr of the voltage sensor 6b, and the current detection value I_btr of the current sensor 7d, and performs switching to the gate amplifiers 9a and 9b. Gate pulse signals GP1 and GP2 for commanding on / off of the elements 8a and 8b are output. The gate amplifiers 9a and 9b receive the gate pulse signals GP1 and GP2 and convert the switching elements 8a and 8b into voltage control signals that can be turned on / off based on the gate pulse signals GP1 and GP2, thereby controlling the switching elements 8a and 8b on / off. . Voltage sensor 6b detects a voltage between terminals of power storage device 12, which will be described later. The current sensor 7d detects a current that is input to and output from the power storage device 12 described later.

  As the power storage device 12, when priority is given to instantaneous absorption of regenerative power at the time of instantaneous interruption of an overhead wire, application of an electric double layer capacitor device having high performance charge / discharge input / output characteristics per unit area can be considered. However, since it is important to ensure system redundancy in a railway vehicle, there may be a demand for realizing self-running to a safe retreat location even in a power failure state. For this reason, it can be said that it is appropriate to use a lithium ion battery or the like having a high power storage capacity per unit area.

  The charge / discharge control of the power storage device 12 is realized by periodically turning on / off the switching element 8a or 8b. In this charge / discharge control, the smoothing reactor 11 has a function of keeping the rate of change of the current flowing through the power storage device 12 within a predetermined value.

  First, control for discharging the electric power of the power storage device 12 by periodically turning on / off the switching element 8b will be described.

  When the above-described switching element 8b is turned on for a predetermined time Ton_b, the output terminals of the power storage device 12 are short-circuited. However, the smoothing reactor 11 keeps the current increase rate within a certain value and at the same time passes through the period Ton_b. Power energy obtained by time-integrating the product of the measured current and the voltage across the terminals of the power storage device 12 is stored. After that, when the switching element 8b is turned off for a predetermined time Toft_b, the power energy stored in the smoothing reactor 11 on the DC power unit side passes through the diode part of the switching element 8a and the current collector 1 and the ground point 100. It is discharged to the DC power unit side between the inverter devices 4. At this time, the voltage value V_dc obtained on the DC power side is determined from the ratio of the time Ton_b to turn on the switching element 8b and the time Toft_b to turn off based on the terminal voltage V_btr of the power storage device 12 by the following equation.

V_dc = V_btr × ((Ton_b + Toft_b) / Toft_b) Equation 2
Next, control for charging power to the power storage device 12 by periodically turning on / off the switching element 8a will be described.

  When the aforementioned switching element 8 a is turned on for a predetermined time Ton_a, the potential V_dc of the DC power unit between the current collector 1 and the ground point 100 and the inverter device 4 with respect to the ground point 100 is between the terminals of the power storage device 12. When the voltage is higher than the voltage (potential with respect to the grounding point 100) V_dc (V_dc> V_bc), a current flows from the direct current unit toward the power storage device 12. At this time, the smoothing reactor 11 stores the power energy obtained by time-integrating the product of the current passed during the Ton_a period and the terminal voltage of the power storage device 12 while keeping the current increase rate within a certain value. Thereafter, when the switching element 8a is turned off for a predetermined time Toft_a, the power energy stored in the smoothing reactor 11 on the direct current portion side is released from the high potential side terminal of the power storage device 12 to the low potential side terminal, and the switching element 8b A circuit that returns to the smoothing reactor 11 through the diode portion is formed. That is, during a period in which the switching element 8a is turned off for a predetermined time Toft_a, the electric energy stored in the smoothing reactor 11 continues to flow through the power storage device 12, and the electric energy stored in the smoothing reactor 11 is released. As the charging current increases, the charging current decays. At this time, the inter-terminal voltage value V_btr obtained in the power storage device 12 is determined from the ratio of the time Ton_a to turn on the switching element 8a and the time Toft_a to turn off based on the DC power side V_dc.

V_btr = V_dc × (Ton_a / (Ton_a + Toft_a)) Equation 3
The auxiliary power supply device 14 is connected in the immediate vicinity of the output terminal of the power storage device 12, and has the power stored in the power storage device 12, the power supplied from the overhead line via the current collector 1, or the power supplied from the inverter device 4. In addition, power is supplied to the vehicle controller power supply and certification air conditioner service equipment. As described above, since the power storage device 12 is charged by the regenerative braking power of the inverter device 14, the auxiliary power supply device 14 is first driven by the power stored in the power storage device 12 while the vehicle is stopped or powered. When the amount of power storage decreases and sufficient power cannot be supplied to the vehicle controller or service device, the power supplied from the overhead line via the current collector 1 by turning on / off the switching element 9a, or The electric power supplied from the inverter device 4 is controlled in accordance with the voltage level of the power storage device 12 and supplied to the auxiliary power supply device 14.

  With the above configuration, the time change rate dV_dc / dt of the DC part voltage detection value V_dc of the voltage sensor 6a is calculated by the control device 10, and when dV_dc / dt exceeds a predetermined value, the current detection value I_btr of the current sensor 7d is calculated. The switching elements 8a and 8b can be driven by controlling the gate pulse signals GP1 and GP2 which are the outputs of the gate amplifiers 9a and 9b so as to follow a predetermined charging current command value I_abs_cmd (not shown).

  Further, a charging current command value I_regen_cmd (not shown) that can charge the power storage device 12 is calculated by the control device 10 from the regenerative power P_regen of the inverter device 4 and the inter-terminal voltage V_btr of the power storage device 12, and the current sensor 7d. The switching elements 8a and 8b can be driven by controlling the gate pulse signals GP1 and GP2 that are the outputs of the gate amplifiers 9a and 9b so that the detected current value I_btr of the current follows the charging current command value I_regen_cmd.

  As a result, when the current path from the current collector to the power line is interrupted during regenerative braking, charging control that instantly absorbs regenerative power with the power storage device based on the rate of change in the voltage detection value of the inverter DC section is started. In addition, it is possible to realize a drive system for an electric vehicle that can continuously absorb regenerative power in the power storage device. In addition, the regenerative power absorbed by the power storage device can be used preferentially for driving the auxiliary power supply that always supplies power to the vehicle controller power supply, lighting and air conditioner service equipment, without operating the switching element. In addition, it is possible to promote the discharge of the power storage device with low loss and to secure a regenerative power absorption margin. In addition, since the auxiliary power supply device can be driven by a stable direct current to which the power storage device is connected, the allowable range of the input voltage fluctuation of the auxiliary power supply device can be set small, and the auxiliary power supply cost can be suppressed.

  FIG. 8 is a diagram showing a device configuration of the fourth embodiment in the electric vehicle drive system of the present invention.

  The DC power fed from the current collector 1 is input to the inverter device 4 after the fluctuation in the high frequency region is removed by the LC filtering circuit constituted by the filter reactor 2 and the filter capacitor 3. The inverter device 4 converts the input DC power into three-phase AC power having a variable voltage variable frequency (VVVF), and drives the main motors 5a and 5b. Although the case where two main motors are driven by the inverter device 4 is shown here, the number of main motors driven by the inverter device 4 is not limited. The voltage sensor 6 a detects the DC part voltage V_dc across the filter capacitor 3. The voltage sensors 7a, 7b, and 7c detect the current flowing through the three-phase AC power line between the inverter device 4 and the main motors 5a and 5b for each phase, and input the detected current to the inverter device 4. The ground point 100 determines the reference potential of this circuit. The switching elements 8a and 8b are arranged in series between the high-potential side and the low-potential side in the DC power unit between the current collector 1 and the ground point 100 and the inverter device 4 described above. The switching element 8c is arranged in series with the brake resistor 13 between the high potential side and the low potential side of the DC power unit between the current collector 1 and the grounding point 100 and the inverter device 4 described above. The voltage sensor 6b is disposed between the power line of the smoothing reactor 11 and the current sensor 7d, and detects the inter-terminal voltage V_btr of the power storage device 12. The voltage sensor 6b is arranged between the power line of the smoothing reactor 11 and the current sensor 7d. However, even if it is arranged between the power line of the power storage device 12 and the smoothing reactor 11, the voltage between terminals of the power storage device 12 described later is used. V_btr can be detected.

  The control device 10 receives the regenerative power P_inv of the inverter device 4, the voltage detection value V_dc of the voltage sensor 6a, the voltage detection value V_btr of the voltage sensor 6b, and the current detection value I_btr of the current sensor 7d, and inputs the gate amplifiers 9a, 9b, 9c. In addition, gate pulse signals GP1, GP2, GP3 for commanding on / off of the switching elements 8a, 8b, 8c are output. The gate amplifiers 9a, 9b, and 9c receive the gate pulse signals GP1, GP2, and GP3 and convert the switching elements 8a and 8b into voltage control signals that can be turned on / off based on the gate pulse signals GP1, GP2, and GP3, and the switching elements 8a, 8b, and 8c. ON / OFF control. Voltage sensor 6b detects a voltage between terminals of power storage device 12, which will be described later. The current sensor 7d detects a current that is input to and output from the power storage device 12 described later.

  As the power storage device 12, when priority is given to instantaneous absorption of regenerative power at the time of instantaneous interruption of an overhead wire, application of an electric double layer capacitor device having high performance charge / discharge input / output characteristics per unit volume can be considered. However, since it is important to ensure system redundancy in a railway vehicle, there may be a demand for realizing self-running to a safe retreat location even in a power failure state. For this reason, it can be said that it is appropriate to configure a lithium ion battery or the like having a high power storage capacity per unit area.

  The charge / discharge control of the power storage device 12 is realized by periodically turning on / off the switching elements 8a and 8b. In this charge / discharge control, the smoothing reactor 11 has a function of keeping the rate of change of the current flowing through the power storage device 12 within a predetermined value.

  First, control for discharging the electric power of the power storage device 12 by turning on / off the switching element 8b will be described.

  When the above-described switching element 8b is turned on for a predetermined time Ton_b, the output terminals of the power storage device 12 are short-circuited, but the smoothing reactor 11 keeps the current increase rate within a constant value and at the same time flows in the Ton_b period. The power energy obtained by time-integrating the product of the terminal voltage of the power storage device 12 of the current thus obtained is stored. After that, when the switching element 8b is turned off for a predetermined time Toft_b, the power energy stored in the smoothing reactor 11 on the DC power unit side passes through the diode part of the switching element 8a, and the current collector 1 and the grounding point 100 and the inverter. It is discharged to the DC power unit side between the devices 4. At this time, the voltage value V_dc obtained on the direct current side is determined from the ratio of the time Ton_b to turn on the switching element 8b and the time Toft_b to turn off based on the terminal voltage V_btr of the power storage device 12 by the following equation.

V_dc = V_btr × ((Ton_b + Toft_b) / Toft_b) Equation 2
Next, control for charging the power storage device 12 by turning on / off the switching element 8a will be described.

  When the aforementioned switching element 8a is turned on for a predetermined time Ton_a, the potential V_dc of the DC power unit between the current collector 1 and the ground point 100 and the inverter device 4 with respect to the ground point 100 becomes the terminal of the power storage device 12. When the voltage is higher than the inter-voltage (potential with respect to the ground point 100) V_dc (V_dc> V_bc), a current flows from the DC power unit toward the power storage device 12. At this time, the smoothing reactor 11 stores the power energy obtained by time-integrating the product of the current passed during the Ton_a period and the terminal voltage of the power storage device 12 while suppressing the current increase rate within a certain value. Thereafter, when the switching element 8a is turned off for a predetermined time Toft_a, the power energy stored in the smoothing reactor 11 on the DC power unit side is released from the high potential side terminal of the power storage device 12 to the low potential side terminal, and the diode of the switching element 8b After that, the circuit returns to the smoothing reactor 11 to form a circuit. That is, as long as the switching element 8a is turned off for a predetermined time Toft_a, the power energy stored in the smoothing reactor 11 continues to flow through the power storage device 12, and the power energy stored in the smoothing reactor 11 is released. The charging current decays. At this time, the inter-terminal voltage value V_btr obtained by the power storage device 12 is determined from the ratio of the time Toft_a for turning on the switching element 8a and the time Toft_a for turning off based on the DC power side V_dc as follows.

V_btr = V_dc × (Ton_a / (Ton_a + Toff_a)) Equation 3
Further, control (brake chopper control) for instantaneously converting the electric power of the direct current portion from the brake resistor 13 to heat energy by turning on / off the switching element 8c will be described.

  When the aforementioned switching element 8c is turned on for a predetermined time Ton_c, the current collector 1 and the DC power unit between the contact point 100 and the inverter device 4 are connected via the brake resistor 13 during that period. Accordingly, when the inverter device 4 is appropriately controlled to turn on / off the switching element 8c during the regenerative brake operation, a part or all of the inverter regenerative power can be consumed by the brake resistor 13. It is discharged to the DC power unit side between the current collector 1 and the contact point 100 and the inverter device 4. At this time, the conduction power I_brr of the brake resistor 13 is determined from the ratio of the time Ton_b for turning on the switching element 8b and the time Toff_b for turning off based on the regenerative brake current I_inv_regen as follows.

I_r_brk = I_inv_regen × (Ton_a / (Ton_a + Toff_a)) Equation 4
The auxiliary power supply device 14 is connected to the output terminal of the power storage device 12, and is based on the power stored in the power storage device 12, the power supplied from the overhead line via the current collector 1, or the power supplied from the inverter device 4. In addition, power is supplied to vehicle controller power supplies, lighting and air conditioner service equipment. As described above, since the power storage device 12 is charged by the regenerative control power of the inverter device 14, the auxiliary power supply device 14 is first driven by the power stored in the power storage device 12 when the vehicle is stopped or powered. . When the amount of power storage decreases and sufficient power cannot be supplied to the vehicle controller or service device, the power supplied from the overhead line via the current collector 1 by turning on / off the switching element 9a, or The electric power supplied from the inverter device 4 is controlled in accordance with the voltage level of the power storage device 12 and supplied to the auxiliary power supply device 14.

  With the above configuration, the time change rate dV_dc / dt of the DC voltage detection value V_dc of the voltage sensor 6b is produced by the control device 10, and when the dV_dc / dt exceeds a predetermined value, the current detection value I_brr of the current sensor 7e is obtained. The switching element 8c can be driven by controlling the gate pulse signal GP3, which is the output of the gate amplifier 9c, so as to follow a predetermined charging current command value I_abs_cmd (not shown).

  Further, a charging current command value I_regen_cmd (not shown) that can charge the power storage device 12 is calculated by the control device 10 from the regenerative power P_inv of the inverter device 4 and the inter-terminal voltage V_btr of the power storage device 12, and the current sensor 7d. The switching elements 8a and 8b can be driven by controlling the gate pulse signals GP1 and GP2 that are the outputs of the gate amplifiers 9a and 9b so that the detected current value I_btr of the current follows the charging current command value I_regen_cmd_b.

  As a result, when the current path from the current collector to the power line is interrupted during regenerative braking, charging control that instantly absorbs regenerative power with the power storage device based on the rate of change in the voltage detection value of the inverter DC section is started. In addition, a drive system for an electric vehicle that can continuously absorb regenerative power by the power storage device can be realized. In addition, the regenerative power absorbed by the power storage device can be used preferentially for driving the auxiliary power supply that always supplies power to the vehicle controller power supply, lighting and air conditioner service equipment, without operating the switching element. In addition, it is possible to promote the discharge of the power storage device with low loss and to secure a regenerative power absorption margin. In addition, since the auxiliary power supply can be driven by a stable DC power supply to which the power storage device is connected, the allowable range of input voltage fluctuation of the auxiliary power supply can be set small, and the cost of the auxiliary power supply can be suppressed.

It is a figure which shows the apparatus structure of the drive system of the electric vehicle of Example 1 of this invention. It is a block diagram which shows the control system of the drive system of the electric vehicle of Example 1 of this invention. It is a wave form diagram which shows control operation of the drive system of the electric vehicle of Example 1 of this invention. It is a figure which shows the apparatus structure of the drive system of the electric vehicle of Example 2 of this invention. It is a block diagram which shows the control system of the drive system of the electric vehicle of Example 2 of this invention. It is a wave form diagram which shows the control action of the drive system of the electric vehicle of Example 2 of this invention. It is a figure which shows the apparatus structure of the drive system of the electric vehicle of Example 3 of this invention. It is a figure which shows the apparatus structure of the drive system of the electric vehicle of Example 4 of this invention. It is an example of an apparatus structure in the case of attaching the electrical storage apparatus which absorbs the regenerative electric power of a prior art example to the inverter apparatus of a vehicle upper side.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Current collector 2 Filter reactor 3 Filter capacitor 4 Inverter device 5 Main motor 6 Voltage sensor 7 Current sensor 8 Switching element 9 Gate amplifier 10 Control device 11 Smoothing reactor 12 Power storage device 13 Brake resistor 14 Auxiliary power supply device 51 Change rate calculation part 52 Comparator 53 Selector 54 OR Circuit 55 Integrator 56 Low Level Selector 57 High Level Selector 58 Multiplier 59 Divider 60 Adder 61 Gate Pulse Operation Unit 62 Stabilization Controller 101 Reactor 102 Power Storage Device 103 Main Switch 104 Smoothing Reactor 105 Inverter 106 Motor 107 Smoothing capacitor 108 DC power supply 110 Overhead wire 111 Switching element 113 Current detector 114 Current detector.

Claims (6)

Current collecting means for obtaining power from the power line;
Inverter means for converting DC power based on the power line power into AC power;
A capacitor disposed on the DC side of the inverter means;
An electric motor driven by the inverter means;
Power storage means capable of charging and discharging power;
Switch means for adjusting and controlling the current flowing between the DC side of the inverter means and the power storage means;
Means for detecting the voltage of the capacitor,
When the instantaneous interruption of the current path from the current collecting means to the power line is detected based on the change rate of the voltage detection value of the capacitor, the switch means selectively controls the increase rate and the recovery rate of the conduction current. Instantaneous power absorption control in which current is passed from the DC side of the inverter means to the power storage means side and regenerative power generated by the electric motor is charged by the power storage means, and after the completion of the instantaneous power absorption control drive system for a railway vehicle, characterized in that performing the regenerative power absorption control based on the detected value of the energizing current. Current collecting means for obtaining power from the power line;
Inverter means for converting DC power based on the power line power into AC power;
A capacitor disposed on the DC side of the inverter means;
An electric motor driven by the inverter means;
Power storage means capable of charging and discharging power;
First switch means for adjusting and controlling a current flowing between the DC side of the inverter means and the power storage means;
Means for detecting the voltage of the capacitor;
Resistance means for discharging power on the DC side of the inverter means;
Second switch means for adjusting and controlling the current flowing through the resistance means;
When a momentary interruption of the current path from the current collector to the power line is detected based on the rate of change of the voltage detection value of the capacitor,
Performing control to control the second switch means to consume the regenerative power generated by the motor by the resistance means;
The first switch means selectively controls the increasing rate and the recovery rate of the flowing current to flow current from the DC side of the inverter means to the power storage means side, and the regenerative power generated by the motor is supplied. drive system for a railway vehicle, characterized in that performing the regenerative power absorption control based on the detected value of the instantaneous power absorbed and control the energizing current after completion of the instantaneous power absorbed controlling charging in the power storage means. Current collecting means for obtaining power from the power line;
First inverter means for converting DC power based on the power line power into AC power;
A capacitor disposed on the DC side of the first inverter means;
An electric motor driven by the first inverter means;
Power storage means capable of charging and discharging power;
Means for detecting the amount of electricity stored in the power storage means;
Switch means for adjusting and controlling the current flowing between the DC side of the first inverter means and the power storage means;
Means for detecting the voltage of the capacitor;
Comprising second inverter means for converting DC power supplied by the power storage means into AC power;
When a momentary interruption of the current path from the current collector to the power line is detected based on the rate of change of the voltage detection value of the capacitor,
The switch means selectively controls the increase rate and recovery rate of the conduction current to flow current from the DC side of the first inverter means to the power storage means side, and the regenerative power generated by the motor is supplied. drive system for a railway vehicle, characterized in that performing the regenerative power absorption control based on the detected value of the instantaneous power absorbed and control the energizing current after completion of the instantaneous power absorbed controlling charging in the power storage means. Current collecting means for obtaining power from the power line;
First inverter means for converting DC power based on the power line power into AC power;
A capacitor disposed on the DC side of the first inverter means;
An electric motor driven by the first inverter means;
Power storage means capable of charging and discharging power;
Means for detecting the amount of electricity stored in the power storage means;
First switch means for adjusting and controlling a current flowing between the DC side of the first inverter means and the power storage means;
Means for detecting the voltage of the capacitor;
Resistance means for discharging electric power on the DC side of the first inverter means;
Second switch means for adjusting and controlling the current flowing through the resistance means;
Comprising second inverter means for converting DC power supplied by the power storage means into AC power;
When a momentary interruption of the current path from the current collector to the power line is detected based on the rate of change of the voltage detection value of the capacitor,
The first switch means is turned on / off by selecting an increase rate and a recovery rate of the conduction current ,
Completion of instantaneous power absorption control and instantaneous power absorption control in which current is passed from the DC side of the first inverter means to the power storage means side and regenerative power generated by the motor is charged by the power storage means after performs the regenerative power absorption control based on the detection value of the energizing current,
A railcar drive system characterized in that the second switch means is controlled so that the regenerative power generated by the electric motor is consumed by the resistance means. The drive system according to claim 1 or claim 3,
Means for detecting a current flowing through the switch means;
The drive system for a railway vehicle, wherein the switch means is controlled so that a detected value of the conduction current matches a predetermined charging current command value . The drive system according to claim 2 or 4 ,
Means for detecting a current flowing through the first switch means;
The railway vehicle drive system, wherein the first switch means is controlled so that a detected value of the conduction current matches a predetermined charging current command value.

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