JP6146615B2 - Rotating machine control device - Google Patents

Description

  The present invention relates to a rotating machine control device, and more particularly to a rotating machine control device including an inverter.

  Conventionally, the operation of a rotating machine such as a motor or a generator is controlled using an inverter. The inverter includes a plurality of switching elements. An AC voltage is generated from the DC voltage by switching each element on and off according to a switching signal supplied from the control device. The rotating machine is driven by an AC voltage supplied from an inverter.

  As an inverter control method, a pulse width modulation (PWM) method and a pulse amplitude modulation (PAM) method are known.

  In the PWM method, the amplitude of the pulse signal is fixed. By changing the pulse width of the pulse signal, the switching element in the inverter is switched on and off. When the inverter is driven by the PWM method, the pulse width of the pulse signal becomes narrower as the output of the rotating machine becomes lower. As a result, since the high frequency component contained in the alternating voltage increases, there is a problem that the loss of the rotating machine increases.

  In the PAM system, the pulse width of the pulse signal is fixed. By changing the amplitude of the pulse signal, the switching element in the inverter is switched on and off. However, when the rotating machine is driven at a low output, the amplitude of the pulse signal must be lowered. As a result, since the voltage supplied to the rotating machine is lowered, there is a problem that the current capacity of the inverter is increased and the response of the inverter is lowered.

  Patent Document 1 discloses a control device for a centrifuge motor. This control device uses PWM control to control an inverter connected to a motor. Patent Document 2 discloses a centrifuge. This centrifuge controls the voltage applied to the motor using PWM control.

  However, the techniques disclosed in these documents do not solve the problems of the PWM method and the PAM method described above.

JP-A-9-56187 Japanese Patent No. 3360400

  An object of the present invention is to provide a rotating machine control device capable of suppressing an increase in loss when the rotating machine is driven at a low output and improving responsiveness when driven at a low output.

  The rotating machine control device according to the present invention supplies an inverter, and either the first DC voltage or the second DC voltage lower than the first DC voltage to the inverter, and the first DC voltage Is supplied to the inverter, a switching signal based on a first pulse width modulation method is supplied to the inverter, and a second pulse width modulation method is applied to the inverter when the second DC voltage is supplied to the inverter. And a control device for supplying a switching signal based on the inverter to the inverter. In the first pulse width modulation method, a first pulse signal is used. In the second pulse width modulation method, a second pulse signal having an amplitude smaller than the amplitude of the first pulse signal and a pulse width larger than the pulse width of the first pulse signal is used. The total value of the area of the first pulse signal per cycle of the AC voltage output from the inverter is the same as the total value of the area of the second pulse signal per cycle.

  According to this configuration, when the first DC voltage is supplied to the inverter, the control device generates a switching signal that controls the operation of the inverter using the first pulse signal. On the other hand, when supplying a second DC voltage smaller than the first DC voltage to the inverter, the control device generates a switching signal for controlling the operation of the inverter using the second pulse signal. The amplitude of the second pulse signal is smaller than the amplitude of the first pulse signal, and the pulse width of the second pulse signal is larger than the pulse width of the first pulse signal. The total area value of the first pulse signal is the same as the total area area of the second pulse signal. Note that the total value of the first pulse signal and the total value of the area of the second pulse signal do not have to be completely coincident with each other as long as they are substantially the same. Thereby, the alternating voltage with few high frequency components can be produced | generated using a PWM system. Therefore, an increase in loss when the rotating machine is driven at a low output can be suppressed.

  In addition, when the second DC voltage is supplied to the inverter, the maximum amplitude of the AC output from the inverter is smaller than that when the second DC voltage is supplied to the inverter, and the rotating machine outputs at a low drive. At this time, by making the pulse width of the second pulse signal larger than the pulse width of the first pulse signal, the AC voltage output from the inverter can be made larger than when the conventional PAM method is used. . Therefore, the response when the rotating machine is driven at a low output can be improved.

  In the rotating machine control device, the control device includes a first instruction signal corresponding to a first output of the rotating machine, and a second instruction signal corresponding to a second output smaller than the first output. When the rotating machine is driven with a first output, the switching signal based on the first pulse signal is supplied to the inverter, and the rotating machine is driven with a second output. A control unit that supplies a switching signal based on the second pulse signal to the inverter; and when the first instruction signal is received from the control unit, an input DC voltage is adjusted to the first DC voltage, And a voltage adjustment unit that adjusts the input DC voltage to the second DC voltage when the second instruction signal is received from the control unit.

  According to this configuration, when the rotating machine is driven with the first output, the control device supplies the first DC voltage to the inverter and generates the first switching signal from the first pulse signal. When the rotating machine is driven with a second output smaller than the first output, the control device supplies a second DC voltage lower than the first DC voltage to the inverter, and the first pulse signal A switching signal is generated using a second pulse signal having a pulse width larger than the pulse width of the second pulse signal. Thereby, since the high frequency component contained in an alternating voltage is suppressed, the increase in the eddy current loss which arises when a rotary machine operate | moves with a low output can be suppressed.

  In the rotating machine control device, the control unit holds a relationship diagram indicating a relationship between the torque and the rotation speed of the rotating machine, and is included in the relationship diagram and an output command instructing a driving condition of the rotating machine. The first or second instruction signal is output with reference to the torque value and the rotation speed included in the output command, and the first or second instruction signal is output based on the torque value and the rotation speed included in the output command. 2 pulse signals are generated.

  According to this configuration, the pulse signal used for generating the switching signal can be changed according to the driving condition of the rotating machine. Therefore, even if the driving conditions of the rotating machine change, an increase in loss can be suppressed.

  The engine unit of the present invention includes a rotating machine control device of the present invention, a rotating machine controlled by the rotating machine control device of the present invention, and an engine including a rotating shaft connected to the rotating shaft of the rotating machine.

  According to said structure, when using a rotary machine as a power source with an engine, the increase in the loss when driving a rotary machine with low output can be suppressed.

It is a functional block diagram which shows the structure of a drive device provided with the rotary machine control apparatus which concerns on embodiment of this invention. It is a functional block diagram which shows the structure of the control part shown in FIG. It is a figure which shows the pulse signal which the pulse signal generation part shown in FIG. 2 produces | generates when driving a rotary machine with high output. It is a figure which shows the pulse signal which the pulse signal generation part shown in FIG. 2 produces | generates when driving a rotary machine with low output. It is a graph which shows an example of the relationship diagram which the control part shown in FIG. 1 hold | maintains. It is a flowchart which shows operation | movement of the control part shown in FIG. It is a figure which shows the pulse signal used when driving a rotary machine with high output by the rotary machine control apparatus shown in FIG. It is a figure which shows the pulse signal used when driving a rotary machine with low output by the rotary machine control apparatus shown in FIG. It is a BH curve when a rotary machine is driven with high output by the rotary machine control apparatus shown in FIG. It is a BH curve when a rotary machine is driven with low output by the rotary machine control apparatus shown in FIG. It is a figure which shows the pulse signal used when driving the rotary machine shown in FIG. 1 by the conventional PWM system with low output. It is a BH curve when a rotary machine is driven by low output by the conventional PWM system. It is a graph which shows the modification of the boundary line in the relationship diagram shown in FIG. It is a graph which shows the other modification of the boundary line in the relationship diagram shown in FIG. It is a graph which shows an example at the time of dividing the drive state of a rotary machine into four in the relationship diagram shown in FIG. It is a graph which shows the other example at the time of dividing the drive state of a rotary machine into four in the relationship diagram shown in FIG. It is a graph which shows the other example at the time of dividing the drive state of a rotary machine into four in the relationship diagram shown in FIG. It is a graph which shows the other example at the time of dividing the drive state of a rotary machine into four in the relationship diagram shown in FIG. It is a table which shows the relationship between the rotational speed in the relationship diagram shown to FIG. 14A-FIG. 14D, and a torque. It is a figure which shows one usage example of the rotary machine control apparatus shown in FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

{1. Configuration of rotating machine control device 3}
FIG. 1 is a functional block diagram of a drive device 100 including a rotating machine control device 3 according to the present embodiment. As shown in FIG. 1, the driving device 100 converts an AC voltage Vs supplied from the AC power source 1 into a DC voltage. .) Is generated to drive AC voltage Vd1 or Vd2. Details of the AC voltages Vd1 and Vd2 will be described later.

  The alternating voltages Vs, Vd1, and Vd2 are three-phase alternating currents having a U phase, a V phase, and a W phase, respectively. In FIG. 1, the display of each phase of the AC voltage is omitted. Hereinafter, in the description of the AC voltages Vs, Vd1, and Vd2, no particular mention is made of each phase.

  Hereinafter, the operation of the rotating machine control device 3 when using the rotating machine 200 as a motor will be described, and the description of the operation of the rotating machine control device 3 when using the rotating machine 200 as a generator will be omitted.

  The drive device 100 includes a converter 2 and a rotating machine control device 3.

  Converter 2 rectifies AC voltage Vs supplied from AC power supply 1 to generate DC voltage Vc. Note that the drive device 100 may be configured without the converter 2. In this case, the driving device 100 may be supplied with the DC voltage Vc from a DC power source (not shown) instead of the AC power source 1.

  The rotating machine control device 3 generates the AC voltage Vd1 or Vd2 for rotating the rotating machine 200 under the driving condition specified by the output command 49 from the DC voltage Vc supplied from the converter 2. The rotating machine control device 3 includes a control device 30 and an inverter 34.

{1.1. Configuration of Control Device 30}
Control device 30 generates DC voltage V <b> 1 or V <b> 2 from DC voltage Vc supplied from converter 2. The voltage value of the DC voltage V1 is larger than the voltage value of the DC voltage V2. The control device 30 supplies either the DC voltage V1 or V2 to the inverter 34. Hereinafter, the reference numerals of the DC voltages V1 and V2 are appropriately used as the voltage values of the DC voltages V1 and V2.

  In addition, the control device 30 supplies the inverter 34 with a switching signal 41 based on the first PWM method when the DC voltage V1 is supplied to the inverter 34. The control device 30 supplies the inverter 34 with a switching signal 42 based on the second PWM method when the DC voltage V <b> 2 is supplied to the inverter 34. The first PWM method and the second PWM method will be described later.

  The inverter 34 converts the DC voltage V1 into the AC voltage Vd1 using the switching signal 41 supplied from the control device 30. That is, the AC voltage Vd1 is a voltage supplied to the rotating machine 200 when the rotating machine 200 is driven at a high output. The inverter 34 converts the DC voltage V2 into the AC voltage Vd2 using the switching signal 42 supplied from the control device 30. That is, the AC voltage Vd2 is a voltage supplied to the rotating machine 200 when the rotating machine 200 is driven at a low output.

  The control device 30 includes a control unit 31, a voltage adjustment unit 32, and a capacitor 33.

  Based on the output command 49, the control unit 31 determines whether to drive the rotating machine 200 with high output or low output. When the rotating machine 200 is driven at a high output, the control unit 31 supplies an instruction signal 43 a indicating driving at a high output to the voltage adjusting unit 32 and supplies a switching signal 41 to the inverter 34. When the rotating machine 200 is driven at a low output, the control unit 31 supplies an instruction signal 43b indicating driving at a low output to the voltage adjusting unit 32 and supplies a switching signal 42 to the inverter 34.

  When receiving the instruction signal 43a, the voltage adjustment unit 32 adjusts the DC voltage Vc to the DC voltage V1. On the other hand, when receiving the instruction signal 43b, the voltage adjustment unit 32 adjusts the DC voltage Vc to the DC voltage V2. The voltage adjustment unit 32 is desirably a circuit or a circuit element with a small loss, such as a switching circuit such as a step-up / down circuit.

  The capacitor 33 smoothes the DC voltage V1 or V2 and reduces noise included in the DC voltage V1 or V2. One of the capacitors 33 is connected to the output terminal 32a of the voltage adjusting unit 32, and the other is connected to the output terminal 32b. The DC voltage V1 or V2 is output from the output terminal 32a. The output terminal 32b is grounded.

{1.2. Configuration of control unit 31}
FIG. 2 is a functional block diagram of the control unit 31 shown in FIG. The control unit 31 includes an output determination unit 35, a pulse signal generation unit 36, and a switching signal generation unit 37.

  The output determination unit 35 drives the rotating machine 200 with high output based on the torque command 47 and the rotation speed command 48 included in the output command 49 and a relationship diagram showing the relationship between the torque and the rotation speed of the rotating machine 200. Whether to drive at low output. When the output determination unit 35 determines to drive with high output, the output determination unit 35 supplies the instruction signal 43 a to the voltage adjustment unit 32 and the pulse signal generation unit 36. When the output determination unit 35 determines to drive with low output, the output determination unit 35 supplies the instruction signal 43 b to the voltage adjustment unit 32 and the pulse signal generation unit 36. Details of the relationship diagram will be described later.

  The pulse signal generator 36 generates the pulse signal 51 when the instruction signal 43a is supplied, and generates the pulse signal 52 when the instruction signal 43b is supplied. The pulse signals 51 and 52 are generated based on the torque command 47 and the rotation speed command 48. The pulse signal 51 is a signal based on the first PWM method, and the pulse signal 52 is a signal based on the second PWM method. The difference between the pulse signals 51 and 52 will be described later.

  When the pulse signal 51 is supplied from the pulse signal generation unit 36, the switching signal generation unit 37 generates the switching signal 41 using the pulse signal 51. When the pulse signal 52 is supplied from the pulse signal generator 36, the switching signal generator 37 generates the switching signal 42 using the pulse signal 52. As described above, the first PWM method uses the pulse signal 51, whereas the second PWM method uses the pulse signal 52.

{1.3. Pulse signals 51, 52}
FIG. 3 is a diagram illustrating an example of the pulse signal 51. FIG. 4 is a diagram illustrating an example of the pulse signal 52. 3 and 4, a period T is one cycle of the AC voltages Vd1 and Vd2.

  As shown in FIGS. 3 and 4, the pulse signal 51 has a constant amplitude A1, and the pulse signal 52 has a constant amplitude A2 smaller than the amplitude A1.

  The pulse width of the pulse signal 52 at a certain time is larger than the pulse width of the pulse signal 51 at that time. For example, the pulse width W2 of the pulse signal 52 at time Ta is larger than the pulse width W1 of the pulse signal 51 at time Ta. The pulse width of the pulse signal 52 at an arbitrary time Ta ′ other than the time T is larger than the pulse width of the pulse signal 51 at the time Ta ′.

  The total area of the pulse signal 51 per cycle is the same as the total area of the pulse signal 52 per cycle. That is, the area of the hatched portion of the pulse signal 51 shown in FIG. 3 is equal to the area of the hatched portion of the pulse signal 52 shown in FIG. The area of the hatched portion of the pulse signal 51 is equal to the area of the hatched portion of the pulse signal 52 is a condition when the control device 30 operates ideally. That is, the area of the hatched portion of the pulse signal 51 is the same as the area of the hatched portion of the pulse signal 52 includes not only the case where these areas completely match but also the case where these areas are substantially equal. For example, the area of the hatched portion of the pulse signal 51 and the area of the hatched portion of the pulse signal 52 depend on the characteristics of electronic components such as transistors constituting the control device 30 and the operating environment (temperature change) of the control device 30. The case where it does not correspond completely is considered.

{1.4. Relationship diagram}
FIG. 5 is a graph illustrating an example of the relationship diagram 5 held by the control unit 31. As shown in FIG. 5, the relationship diagram 5 shows the relationship between the torque of the rotating machine 200 and the rotation speed. In the relational diagram 5, a hatched area 56 indicates that the rotating machine 200 is driven at a low output. The plain area 57 indicates that the rotating machine 200 is driven at a high output.

  A boundary line 55 between the region 56 and the region 57 indicates the relationship between the torque and the rotation speed when the rotating machine 200 is driven at the rated output. When the rotating machine 200 is driven at an output larger than the rated output, the rotating machine 200 is in a high output state, and when the rotating machine 200 is driven at a rated output or less, the rotating machine 200 is in a low output state. That is, the output of the rotating machine 200 indicated by the area 56 is smaller than the output of the rotating machine 200 indicated by the area 57.

  The output determination unit 35 determines in which of the regions 56 and 57 the drive position specified by the output command 49 exists. The drive position is a position on the relationship diagram 5 determined by the designated torque value designated by the torque command 47 and the designated rotational speed value designated by the rotational speed command 48. Specifically, the output determination unit 35 determines that the rotating machine 200 is driven at a high output when the drive position is any of the points P1 to P3 in the region 57. On the other hand, when the drive position is any of the points P4 to P6 in the region 56, the output determination unit 35 determines to drive the rotating machine 200 with a low output.

{2. Operation of Rotating Machine Control Device 3}
The operation of the rotating machine control device 3 will be described with reference to FIG. FIG. 6 is a flowchart showing the operation of the control unit 31. Hereinafter, it is assumed that the configuration shown in FIG. 1 is mounted on an automobile.

  As shown in FIG. 6, the control unit 31 acquires an output command 49 from an MPU (Micro Processing Unit, not shown) of the automobile (step S <b> 11). The control unit 31 extracts a designated torque value and a designated rotation speed value from the output command 49.

  The output determination unit 35 refers to the specified torque value, the specified rotation speed value, and the relationship diagram 5 to determine whether the rotating machine 200 is driven at a high output or a low output by the method described above ( Step S12).

  Control part 31 performs Steps S13-S15, when rotating machine 200 is driven with high output (it is Yes at Step S12). On the other hand, when driving the rotating machine 200 with a low output (No in step S12), the control unit 31 executes steps S16 to S18.

{2.1. When driving at high output (steps S13 to S15)}
The output determination unit 35 supplies an instruction signal 43a indicating that the rotating machine 200 is driven at a high output to the voltage adjustment unit 32 and the pulse signal generation unit 36 (step S13). The voltage adjustment unit 32 adjusts the DC voltage Vc to the DC voltage V1 in accordance with the supplied instruction signal 43a and supplies the adjusted DC voltage V1 to the inverter 34.

  The voltage adjustment unit 32 detects the voltage of the DC voltage V <b> 1 and supplies a voltage value 46 to the control unit 31. In addition to the instruction signal 43a, the control unit 31 outputs an instruction signal for instructing the adjustment of the DC voltage V1 to the voltage adjustment unit 32 based on the supplied voltage value 46. This process is the same in step S16 described later.

  In response to the instruction signal 43a, the pulse signal generator 36 generates a pulse signal 51 for driving the rotating machine 200 with high output based on the specified torque value and the specified rotation speed value (step S14). The pulse signal generator 36 supplies the generated pulse signal 51 to the switching signal generator 37.

  FIG. 7 is a diagram illustrating an example of the pulse signal 51. In FIG. 7, in order to show the correspondence between the pulse signal 51 and one cycle of the AC voltage Vd1, the AC voltage Vd1 is shown. As shown in FIG. 7, the amplitude of the pulse signal 51 is constant at A1. The pulse width of the pulse signal 51 per cycle of the AC voltage Vd1 changes according to the drive position determined by the designated torque value and the designated rotation speed value.

  The pulse signal generator 36 receives supply of the current value 44 a and voltage value 44 b of the AC voltage Vd 1 from the inverter 34 and receives supply of the rotation speed 45 from the rotating machine 200. The rotational speed 45 can be detected by providing a sensor such as a resolver or an encoder provided in the rotating machine 200. Alternatively, a change in inductance or induced voltage in the rotating machine 200 may be detected, and the rotation speed 45 may be calculated based on the detection result. The pulse signal generator 36 calculates torque in the rotating machine 200 based on the supplied current value 44a and voltage value 44b. The pulse signal generator 36 adjusts the pulse width of the pulse signal 51 based on the calculated torque and the rotation speed 45 so that the rotating machine 200 rotates under the driving condition specified by the output command 49. This process is the same in step S17 described later.

  The switching signal generator 37 generates a switching signal 41 based on the pulse signal 51 supplied from the pulse signal generator 36 (step S15), and supplies the generated switching signal 41 to the inverter 34.

  The inverter 34 generates an AC voltage Vd1 from the DC voltage V1 supplied from the voltage adjustment unit 32 by switching on / off of the internal switching element based on the supplied switching signal 41. The rotating machine 200 is driven with high output by the generated AC voltage Vd1.

{2.2. When driving at low output (steps S16 to S18)}
The output determination unit 35 supplies an instruction signal 43b indicating that the rotating machine 200 is driven at a low output to the voltage adjustment unit 32 and the pulse signal generation unit 36 (step S16). The voltage adjustment unit 32 adjusts the DC voltage Vc to the DC voltage V2 (V2 <V1) according to the supplied instruction signal 43b, and supplies the adjusted DC voltage V2 to the inverter 34.

  The pulse signal generation unit 36 generates a pulse signal 52 for driving the rotating machine 200 at a low output based on the designated torque value and the designated rotational speed value in accordance with the instruction signal 43b by the same method as in step S14. (Step S17). The pulse signal generation unit 36 supplies the generated pulse signal 52 to the switching signal generation unit 37.

  FIG. 8 is a diagram illustrating an example of the pulse signal 52. Further, in FIG. 8, the AC voltage Vd2 is shown for the same reason as in FIG. As shown in FIG. 8, the amplitude of the pulse signal 52 is constant at A2. The amplitude A2 is smaller than the amplitude A1. Further, the pulse width of the pulse signal 52 per cycle of the AC voltage Vd2 varies depending on the drive position determined by the designated torque value and the designated rotational speed value.

  The switching signal generator 37 generates a switching signal 42 based on the pulse signal 52 supplied from the pulse signal generator 36 (step S18), and supplies the generated switching signal 42 to the inverter 34.

  The inverter 34 generates an AC voltage Vd <b> 2 from the DC voltage V <b> 2 supplied from the voltage adjustment unit 32 by switching on / off of an internal switching element based on the supplied switching signal 42. The rotating machine 200 is driven at a low output by the generated AC voltage Vd2.

  After step S15 or S18, the control unit 31 returns to step S11 and repeats the process shown in FIG. 6 based on the new output command 49.

{3. Loss suppression}
By using the rotating machine control device 3, an increase in loss when the rotating machine 200 is driven at a low output can be suppressed. The reason will be described below.

  Initially, the loss which generate | occur | produces in the rotary machine 200 is demonstrated, referring FIG. FIG. 9 is a graph showing an example of the BH curve of the rotating machine 200 when the rotating machine 200 is driven at a high output by the rotating machine control device 3. As shown in FIG. 9, a plurality of minor loops 61b exist on the hysteresis loop 61a. In FIG. 9, the display of symbols of some minor loops 61b is omitted.

  The hysteresis loop 61a is drawn when the AC voltage Vd1 is an ideal sine wave. In this case, the minor loop 61b does not occur. The area of the hysteresis loop 61a is magnetic energy generated when the rotating machine 200 is driven by the AC voltage Vd1, and corresponds to thermal energy generated by the rotating machine 200.

  The minor loop 61b is generated on the hysteresis loop 61a when the AC voltage Vd1 includes a high frequency component. The AC voltage Vd1 is generated from the DC voltage Vc by switching on and off the switching element in the inverter 34. Accordingly, the AC voltage Vd1 does not actually become an ideal sine wave but includes a high frequency component.

  The high frequency component causes eddy current loss generated in the rotating machine 200. As the high frequency component increases, the eddy current loss also increases. For this reason, it is desirable that the high-frequency component contained in the AC voltage Vd1 is small.

  Next, the BH curve (FIG. 9) when the rotating machine 200 is driven at a high output is compared with the BH curve when the rotary machine 200 is driven at a low output. FIG. 10 is a graph showing an example of the BH curve of the rotating machine 200 when the rotating machine 200 is driven at a low output by the rotating machine control device 3.

  Also in FIG. 10, the minor loop 61b is generated on the hysteresis loop 61a. However, the size of the minor loop 61b shown in FIG. 10 does not change significantly compared to the BH curve shown in FIG. That is, it can be seen that by using the rotating machine control device 3, eddy current loss does not increase even when the rotating machine 200 is driven at a low output.

  FIG. 11 is a diagram showing a pulse signal 53 when the rotating machine 200 is driven at a low output by the conventional PWM method. FIG. 12 is a BH curve when the rotating machine 200 is driven using the pulse signal 53.

  In FIG. 11, the amplitude of the pulse signal 53 is A1. The number of pulse signals 53 per cycle is the same as the number of pulse signals 51 per cycle. The hysteresis loop 61a shown in FIG. 12 is the same as the hysteresis loop 61a shown in FIGS. In the conventional PWM method, the amplitude is constant regardless of the output of the rotating machine 200. Therefore, in order to drive the rotating machine 200 with low output, it is necessary to reduce the pulse width of the pulse signal 53. As the pulse width of the pulse signal 53 decreases, the high frequency component included in the pulse signal 53 increases. As a result, as shown in FIG. 12, the size of the minor loop 61b appearing on the hysteresis loop 61a increases conversely as the pulse width of the pulse signal 53 decreases.

  Therefore, when the rotating machine 200 is driven by the conventional PWM method, the eddy current loss when driving at a low output increases.

  On the other hand, when the rotating machine control device 3 is used, an increase in the size of the minor loop 61b at the time of low output driving can be suppressed. As described above, since the pulse width of the pulse signal 52 is larger than the pulse width of the pulse signal 51, high frequency components included in the AC voltage Vd2 are suppressed. Further, since the DC voltage V2 is smaller than the DC voltage V1, the maximum amplitude of the AC voltage Vd2 is V2, which is smaller than the maximum amplitude (V1) of the AC voltage Vd1. As a result, the amplitude of the high frequency component included in the AC voltage Vd2 is suppressed. Because of these factors, the size of the minor loop 61b is suppressed, so that an increase in loss when driving at a low output can be suppressed.

  Further, by using the rotating machine control device 3, it is possible to improve the responsiveness when the rotating machine 200 is driven at a low output. In the conventional PAM system, when the amplitude of the pulse signal is reduced in order to drive with a low output, there is a problem that the current flowing through the rotating machine 200 increases and the responsiveness decreases. In the present embodiment, when the rotating machine 200 is driven at a low output, the voltage adjustment unit 32 supplies the inverter 34 with a DC voltage V2 that is smaller than the DC voltage V1 that is used when the rotary machine 200 is driven at a high output. However, by making the pulse width of the pulse signal 52 larger than the pulse width of the pulse signal 51, the AC voltage Vd2 can be increased. As a result, the rotating machine control device 3 can make the current capacity at the time of low output driving smaller than that of the conventional PAM system. Therefore, the rotating machine control device 3 can improve the responsiveness when the rotating machine 200 is driven at a low output.

  As described above, the rotating machine control device 3 uses the pulse width of the pulse signal 52 used when the rotating machine 200 is driven at a low output as compared with the pulse width of the pulse signal 51 used when driven at a high output. Also make it bigger. Further, the rotating machine control device 3 makes the amplitude of the pulse signal 52 smaller than the amplitude of the pulse signal 51. By controlling the pulse width and amplitude of the pulse signal 52 as described above, an increase in loss when the rotating machine 200 is driven at a low output can be suppressed. For this reason, the total value of the area of the pulse signal 51 and the total value of the area of the pulse signal 52 do not necessarily match.

{4. Modification of Relationship Diagram 5}
In the above embodiment, an example in which the boundary line 55 between the region 56 indicating that the rotating machine 200 is driven at a low output and the region 57 indicating that the rotating machine 200 is driven at a high output is determined by the rated output of the rotating machine 200 will be described. did. However, the boundary line 55 is not limited to this, and any boundary line 55 may be used as long as it divides an area 56 indicating driving at a low output and an area 57 indicating driving at a high output.

  13A and 13B are diagrams showing a modification of the boundary line in the relationship diagram 5. In FIGS. 13A and 13B, the boundary lines 55a and 55b are indicated by alternate long and short dash lines. The regions 56 and 57 may be separated by a boundary line 55a, or may be separated by a boundary line 55b. The region 56 is a region below the boundary line 55a or 55b, and the region 57 is a region above the boundary line 55a or 55b.

  13A and 13B, the boundary line 55 is shown in order to show the positional relationship between the boundary lines 55, 55a, and 55b. The inflection point Fa of the boundary line 55a exists on the boundary line 55. The boundary lines 55a and 55b coincide with each other in a region larger than the rotational speed Xb of the inflection point Fb on the boundary line 55b.

  In the above-described embodiment, the example in which the driving state of the rotating machine 200 is divided into two stages (low output and high output) based on the specified torque value and the specified rotation speed value has been described. As shown in FIGS. 14A to 14D, the driving state of the rotating machine 200 may be divided into four stages.

  The driving state of the rotating machine 200 is classified into any one of the areas 71 to 74. 14A to 14D, regions 71 and 74 are indicated by hatching, and regions 72 and 73 are indicated by plain color. In FIG. 14A, regions 71 to 74 are separated by boundary lines 55a and 59a. In FIG. 14B, regions 71 to 74 are separated by boundary lines 55a and 59b. In FIG. 14C, regions 71 to 74 are separated by boundary lines 55b and 59a. In FIG. 14D, regions 71 to 74 are separated by boundary lines 55b and 59b.

  The boundary lines 59a and 59b are straight lines parallel to the vertical axis of the relationship diagram 5, and the rotational speed value of the boundary line 59a is smaller than the rotational speed value of the boundary line 59b.

  FIG. 15 is a diagram showing the relationship between the designated torque value and the designated rotational speed value in the regions 71 to 74 shown in FIGS. 14A and 14B. In FIG. 15, whether the torque is high or low is determined by the boundary line 55a or 55b. The high / low rotational speed is determined by the boundary line 59a or 59b.

  The driving state of the rotating machine 200 in the areas 71 to 74 is as follows. The region 71 is a region where the rotational speed is low and the torque is high. For example, when the rotating machine 200 is mounted on a vehicle as a power source, the region 71 corresponds to a case where a stopped vehicle suddenly starts. A region 72 is a region where both the rotational speed and the torque are low, and corresponds to a case where a car travels at a constant speed on a general road. A region 73 is a region where both the rotational speed and the torque are high, and corresponds to a case where a vehicle traveling on a highway further accelerates. A region 74 is a region where the rotational speed is high and the torque is low, and corresponds to a case where the automobile travels at a constant speed on the highway.

  Hereinafter, the operation of the control unit 31 when using any one of the relationship diagrams 5 of FIGS. 14A to 14D will be described.

  The output determination unit 35 determines the output voltage of the inverter 4 based on the drive position determined by the specified torque value and the specified rotation speed value. Specifically, the output determination unit 35 identifies a region where the drive position exists among the regions 71 to 74 and corresponds to the identified region among the output voltages Vr1 to Vr4 of the inverter 4 corresponding to the regions 71 to 74. Select the output voltage.

  The pulse signal generation unit 36 generates a pulse signal corresponding to the output voltage selected by the output determination unit 35. That is, the amplitude and pulse width of the pulse signal generated by the pulse signal generation unit 36 vary depending on the region where the drive position exists.

  Voltage adjusting unit 32 generates a DC voltage corresponding to output voltages Vr <b> 1 to Vr <b> 4 of inverter 4 corresponding to regions 71 to 74. That is, the DC voltage supplied to the inverter 4 changes according to the region where the drive position exists.

  As described above, when the driving state of the rotating machine 200 is divided into four, and the amplitude and pulse width of the pulse signal are changed according to each driving state, the driving state is divided into two stages as in the above embodiment. The pulse width of the pulse signal can be kept relatively large compared to when evaluating. As a result, high-frequency components included in the pulse signal can be suppressed, and an increase in loss when the rotating machine 200 is driven at a low output can be suppressed.

  That is, the rotating machine control device 3 may divide the relationship diagram 5 into two or more regions and change the amplitude and pulse width of the pulse signal according to which region the drive position is present.

  Moreover, you may enable it to change the boundary line which divides the areas 71-74. Specifically, the control unit 31 selects one of the boundary lines 55a and 55b, and selects one of the boundary lines 59a and 59b. The boundary line may be changed according to the usage frequency of each of the areas 71 to 74.

  The control part 31 should just select a boundary line according to the frequency with which a drive position exists in each area | region. For example, it is assumed that the control unit 31 has selected the relationship diagram shown in FIG. 14A. When the number of times that the drive position exists in the region 71 is extremely larger than the number of times that the drive position exists in the region 72, the control unit 31 selects the boundary line 55b and newly uses the relationship diagram 5 shown in FIG. 14C. As a result, the area 72 becomes wider, and the frequency at which the drive position exists in the area 72 increases. Similarly, the control unit 31 may select one of the boundary lines 59a and 59b according to the frequency with which the drive position exists in the region 71 and the region 73.

  Alternatively, the boundary line may be selected according to the motor specifications, the optimum current value (current value that minimizes copper loss), and the like.

{Other variations}
In the above embodiment, the example in which the control unit 31 holds the graph shown in FIG. 5 as the relational diagram 5 has been described, but the present invention is not limited to this. For example, the control unit 31 may hold data indicating the boundary line 55. In this case, the output determination unit 35 may determine whether the drive position is located above or below the boundary line 55 based on the rotational speed of the drive position. When the drive position is located above the boundary line 55, the output determination unit 35 determines to drive the rotating machine 200 with high output. Conversely, when the drive position is located below the boundary line 55, the output determination unit 35 determines to drive the rotating machine 200 with low output.

  Alternatively, the control unit 31 may hold range data indicating the ranges of the regions 56 and 57. In this case, the output determination unit 35 may determine which of the regions 56 and 57 the drive position is included with reference to the range data.

  In the above embodiment, the example in which the capacitor 33 is provided between the voltage adjustment unit 32 and the inverter 34 has been described. However, the present invention is not limited to this. Capacitor 33 may be provided between converter 2 and voltage adjustment unit 32. Thereby, the noise contained in DC voltage Vc can be reduced. Alternatively, the capacitor 33 may be provided between the voltage adjustment unit 32 and the inverter 34, and the capacitor 33 may be provided between the converter 2 and the voltage adjustment unit 32.

  Moreover, you may control the rotary machine attached to the engine using the rotary machine control apparatus 3 demonstrated in the said embodiment. FIG. 16 is a diagram illustrating an example of use of the rotating machine control device 3. An engine unit 500 shown in FIG. 16 is used, for example, as a power source of an automobile, and includes a rotating machine control device 3, a rotating machine 200, and an engine 400.

  The rotating machine 200 is connected to the rotating shaft of the engine 400. The rotating machine 200 supplies power when the engine 400 starts driving. The rotating machine 200 generates power in accordance with the rotation of the rotating shaft of the engine 400, and supplies the generated power to a battery and a load (not shown). The rotating shaft of rotating machine 200 may be indirectly connected to the rotating shaft of engine 400 via a gear or the like. The rotating machine control device 3 controls the rotating machine 200 as in the above embodiment.

  The control unit 31 described in the above embodiment may be individually made into one chip by a semiconductor device such as an LSI, or may be made into one chip so as to include a part or all of the control unit 31. .

  Further, the method of circuit integration is not limited to LSI, and implementation with a dedicated circuit or a general-purpose processor is also possible. An FPGA (Field Programmable Gate Array) that can be programmed after manufacturing the LSI or a reconfigurable processor that can reconfigure the connection and setting of circuit cells inside the LSI may be used.

  Moreover, a part or all of the control unit 31 may be realized by a program. A part or all of the processing of the control unit 31 is performed by a central processing unit (CPU) in the computer. A program for performing each processing is stored in a storage device such as a hard disk or a ROM, and is read out and executed in the ROM or the RAM.

  In addition, each process of the above embodiment may be realized by hardware, or may be realized by software (including a case where it is realized together with an OS (operating system), middleware, or a predetermined library). Further, it may be realized by mixed processing of software and hardware.

  While the embodiments of the present invention have been described above, the above-described embodiments are merely examples for carrying out the present invention. Therefore, the present invention is not limited to the above-described embodiment, and can be implemented by appropriately modifying the above-described embodiment without departing from the spirit thereof.

DESCRIPTION OF SYMBOLS 1 AC power supply 2 Converter 3 Rotating machine control apparatus 31 Control part 32 Voltage adjustment part 33 Capacitor 34 Inverter 35 Output judgment part 36 Pulse signal generation part 37 Switching signal generation part 100 Drive apparatus 200 Motor generator (rotary machine)

Claims (4)

An inverter;
Either one of a first DC voltage and a second DC voltage lower than the first DC voltage is supplied to the inverter, and a first pulse is supplied when the first DC voltage is supplied to the inverter. A control device for supplying a switching signal based on a width modulation method to the inverter and supplying a switching signal based on a second pulse width modulation method to the inverter when the second DC voltage is supplied to the inverter; Prepared,
In the first pulse width modulation method, a first pulse signal is used,
In the second pulse width modulation method, a second pulse signal having an amplitude smaller than the amplitude of the first pulse signal and a pulse width larger than the pulse width of the first pulse signal is used.
The total value of the area of the first pulse signal per cycle of the AC voltage output from the inverter is the same as the total value of the area of the second pulse signal per cycle. . The rotating machine control device according to claim 1,
The controller is
One of a first instruction signal corresponding to the first output of the rotating machine and a second instruction signal corresponding to a second output smaller than the first output is output, and the rotating machine outputs the first instruction signal. When driving with an output of 1, the switching signal based on the first pulse signal is supplied to the inverter, and when the rotating machine is driven with a second output, the switching signal based on the second pulse signal is A control unit for supplying to the inverter;
When the first instruction signal is received from the control unit, the input DC voltage is adjusted to the first DC voltage, and when the second instruction signal is received from the control unit, the input DC voltage is A rotating machine control device comprising: a voltage adjusting unit that adjusts to a second DC voltage. The rotating machine control device according to claim 2,
The control unit holds a relationship diagram showing a relationship between torque and rotation speed of the rotating machine, the relationship diagram, a torque value included in an output command instructing a driving condition of the rotating machine, and the output command The first or second instruction signal is output with reference to the rotational speed included in the output signal, and the first or second pulse signal is generated based on the torque value and the rotational speed included in the output command. Rotating machine control device. The rotating machine control device according to any one of claims 1 to 3,
A rotating machine controlled by the rotating machine control device;
An engine unit including a rotation shaft coupled to a rotation shaft of the rotating machine.

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