JP2009254206A - Power source control system - Google Patents

Abstract

In a power supply control system, when an abnormality occurs in a cooling system of an inverter, an increase in temperature of a voltage converter is effectively suppressed.
A power supply control system includes a power storage circuit, a voltage converter, an inverter unit, an inverter cooling system, a power supply circuit including a low-voltage operation auxiliary machine, and a control unit. The Control unit 60 acquires the status of the inverter cooling system 40, an inverter cooling system status acquisition module 62 whose state is determined whether normal or abnormal, if the inverter cooling system is abnormal, and W _IN of the power storage device 14 W _OUT and the power storage device W _iN to limit, and W _OUT limiting module 64, in the case of the inverter cooling system 40 is abnormal, is configured to include an auxiliary-output limitation module 66 for limiting the output of the low-voltage operation auxiliary 50 The
[Selection] Figure 1

Description

  The present invention relates to a power supply control system, and more particularly, to a power supply control system that controls the operation of a power supply including a reactor and including a voltage converter that can step up and down between a low voltage and a high voltage.

  Some power supply devices that drive rotating electrical machines are provided with an inverter that is an orthogonal transformation circuit and a converter that performs step-up / step-down between a low voltage and a high voltage. Since these inverters and converters use switching elements to handle large electric power, they generate heat and increase in temperature as they operate. For this purpose, the temperature is monitored, an appropriate cooling system is used, and the output to the load is limited according to the temperature.

  For example, in Patent Document 1, as a vehicle drive system, the temperature of a converter reactor is detected, an annealing process is performed on the detected temperature, and when the cooling water temperature is high, the annealing process coefficient is increased to increase the temperature gradient. Is increased to reflect the temperature change, and it is disclosed to limit the load factor for the torque current based on this temperature.

  Further, in Patent Document 2, in the voltage converter, when an auxiliary machine is connected to the low voltage side of the boost converter, a large current obtained by adding the maximum value of the auxiliary machine current to the maximum value of the battery current at the time of regeneration is obtained. It has been pointed out that an overvoltage occurs because it can be energized. Here, it is disclosed that a maximum allowable current is set in the boost converter, and within that range, a load is limited from a plurality of auxiliary machines having a low necessity.

JP 2006-149064 A JP 2006-288024 A

  When the temperature of the inverter rises when an abnormality occurs in the cooling system of the inverter, for example, the drive output of the rotating electrical machine that is the load or the regenerative power is limited to suppress the operating power of the inverter. Can do. Moreover, when the temperature of the converter which is a voltage converter rises in connection with this, the input / output of the electric power with respect to the secondary battery which is a low voltage electrical storage apparatus can be restrict | limited, and the electric power which flows into a voltage converter can be restrict | limited. .

  By the way, when an auxiliary machine that operates at a low voltage is connected between the low-voltage power storage device and the voltage converter, if the input / output of the power of the low-voltage power storage device is restricted, the power supplied to the auxiliary machine There may be a shortage of operating power. At this time, power is supplied from the high voltage side via the voltage converter to compensate for the insufficient power. That is, the inverter also performs the corresponding operation, and a current also flows through the reactor of the voltage converter. Thus, although the input / output of electric power of the low-voltage power storage device is restricted, the temperature of the inverter also rises and the temperature of the reactor also rises. As described above, in the conventional technique, the temperature rise suppression of the inverter and the voltage converter may be insufficient.

  The objective of this invention is providing the power supply control system which makes it possible to suppress the temperature rise of a voltage converter effectively. Another object is to provide a power supply control system that can effectively suppress the temperature rise of the voltage converter when an abnormality occurs in the cooling system of the inverter.

  A power supply control system according to the present invention includes a reactor, and a voltage converter capable of performing step-up / step-down between a low voltage and a high voltage, and a load and a voltage converter operating with high voltage AC power. Auxiliary equipment output restriction that limits the output of the auxiliary equipment according to the reactor temperature for the auxiliary equipment that is connected and arranged in parallel between the low-voltage power storage device and the voltage converter and operates with low-voltage power And means.

  The power supply control system according to the present invention preferably includes means for acquiring the state of the inverter cooling system, and the auxiliary machine output restricting means further restricts the output of the auxiliary machine according to the state of the inverter cooling system.

  Moreover, the power supply control system according to the present invention preferably includes a power storage device input / output limiting unit that limits input power and output power to the low voltage power storage device in accordance with the temperature of the reactor.

  In the power supply control system according to the present invention, the auxiliary machine is preferably a DC / DC converter or an air compressor.

  With the above configuration, the power supply control system limits the output of the auxiliary machine according to the temperature of the reactor for the auxiliary machine that is connected and arranged in parallel between the low-voltage power storage device and the voltage converter. As a result, for example, when the input / output of the power of the low-voltage power storage device is restricted, the voltage converter is prevented from supplying power to the auxiliary machine, the inverter temperature rise, the voltage converter temperature rise Can be suppressed.

  Also, in the power supply control system, the inverter cooling system status is acquired, and the output of the auxiliary machine is limited according to the acquired inverter cooling system status, so when an abnormality occurs in the inverter cooling system, the voltage converter The temperature rise can be effectively suppressed.

  Further, in the power supply control system, the input power and the output power to the low voltage power storage device are limited according to the temperature of the reactor, so that the temperature rise of the reactor can be suppressed.

  Further, in the power supply control system, since the auxiliary machine is a DC / DC converter or an air compressor, by limiting the output of these auxiliary machines, for example, when an abnormality occurs in the cooling system of the inverter, Even when the power input / output of the voltage storage device is restricted, it is possible to effectively suppress the temperature rise of the voltage converter.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following, a motor / generator mounted on a vehicle will be described as a rotating electrical machine. However, if the vehicle is a vehicle mounted with a power circuit including an inverter and a voltage converter, a hybrid mounted with an engine and the rotating electrical machine. In addition to the vehicle, an electric vehicle not equipped with an engine, a vehicle equipped with a fuel cell, and the like may be used. The rotating electrical machine may be a stationary motor / generator, for example, other than the one mounted on the vehicle. In addition, the rotating electrical machine may simply have a function as a motor, or may simply have a function as a generator. In the following description, control of a power supply circuit including two inverters corresponding to a rotating electric machine will be described. Of course, only one inverter corresponding to one rotating electric machine may be provided. May be provided. The power supply circuit is described as having a power storage device, a system main relay, a voltage converter, a smoothing capacitor, a discharge resistor, and an inverter circuit, but these elements may be omitted as appropriate, and other elements May be added as appropriate. In addition, as auxiliary machines that operate at low voltage, a DC / DC converter, an electric control unit for air conditioning (A / C Electric Control Unit: A / C-ECU), an inverter for air conditioning (A / C inverter), a compressor for air conditioning (COMP) will be described, but other than these, for example, various low-voltage operation motors, ECUs, lamps, various on-vehicle electronic devices such as audio devices, and the like may be used.

  In the following description, a voltage of about 600 V, which is an operating voltage of an inverter that controls the rotating electrical machine, is assumed to be a high voltage, and a voltage of about 200 V to about 300 V, which is a voltage across the power storage device, is assumed to be a low voltage. These voltage values are illustrative examples, and of course other voltage values may be used. An auxiliary machine that operates at a low voltage is a device that operates directly at a voltage of about 200 V to about 300 V, which is the voltage across the power storage device, and further reduces the voltage of about 200 V to about 300 V, For example, it includes various electric devices that operate at a voltage of about 12V. In that sense, an auxiliary machine that operates at a low voltage refers to all devices that operate at a voltage before boosting the voltage converter.

  In the following, similar elements are denoted by the same reference symbols in all the drawings, and redundant description is omitted. In the description in the text, the symbols described before are used as necessary.

  FIG. 1 is a diagram illustrating a configuration of a power supply control system 10 that controls a power supply circuit for a rotating electrical machine or the like mounted on a vehicle. The power supply control system 10 has a function of controlling the operation of each component of the power supply circuit mounted on the vehicle according to the running state of the vehicle. The power supply control system 10 includes a power supply circuit 12 and a control unit 60. In FIG. 1, two rotary electric machines 6 and 8 and an air conditioning compressor 4 are shown, although they are not constituent elements of the power supply control system 10.

  Of the two rotating electrical machines 6 and 8, the first rotating electrical machine (MG1) 6 is, for example, a motor / generator (MG) mounted on a vehicle, and in this case, connected to an engine (not shown). And a three-phase synchronous rotating electric machine having a function of generating electric power by the driving force of the engine. The operation of the first rotating electrical machine 6 is controlled by, for example, a first inverter (MG1 inverter) 36 that operates at a high voltage of about 600V.

  The second rotating electrical machine (MG2) 8 is a motor / generator (MG) mounted on the vehicle, which functions as an electric motor when electric power is supplied and functions as a generator during braking. Electric. The second rotating electrical machine 8 mounted on the vehicle has a function of assisting engine power transmitted to a vehicle axle (not shown) to increase driving force. Similarly to the first rotating electrical machine 6, the second rotating electrical machine 8 is also controlled by a second inverter (MG2 inverter) 38 that operates at a high voltage of about 600 V, for example.

  The air-conditioning compressor (COMP) 4 is a compressor constituting an air-conditioning device mounted on the vehicle. The air conditioning compressor 4 is controlled by an air conditioning inverter (A / C inverter) 58 that operates at a low voltage of about 200V to about 300V, for example.

  The power supply circuit 12 includes a power storage device 14, a system main relay 16, a smoothing capacitor 18 on the power storage device side, a voltage converter 20, a smoothing capacitor 30 on the inverter side, an inverter unit 34, an inverter cooling system 40, and a low-voltage operation auxiliary device 50. Consists of including.

  The power storage device 14 is a chargeable / dischargeable secondary battery. Since the power storage device 14 is disposed on the low voltage side of the voltage converter 20, it can be called a low voltage power storage device. As the power storage device 14, for example, a lithium ion assembled battery, a nickel hydride assembled battery, a capacitor, or the like having a terminal voltage of about 200V to about 300V can be used.

  The system main relay 16 is a high-power interruption device configured to include a high-power relay provided on each of the positive electrode bus and the negative electrode bus of the power storage device 14. The system main relay 16 is connected when the power supply circuit 12 enters the operating state, and is shut off when the power supply circuit 12 finishes operating. As described above, the system main relay 16 can electrically cut off the power storage device 14 from other elements when the power supply circuit 12 is not in operation, so that, for example, the vehicle body of the vehicle can be cut from about 200V. It has a function of safely cutting off from a voltage of about 300 V or a voltage of about 600 V obtained by boosting the voltage.

The smoothing capacitor 18 on the power storage device side provided between the power storage device 14 and the voltage converter 20 is a capacitor having a function of suppressing voltage fluctuation on the low voltage side. Although V _L is illustrated in FIG. 1 as the voltage across the smoothing capacitor 18, this V _L is the voltage on the low voltage side of the voltage converter 20.

  The voltage converter 20 is a step-up / step-down circuit that includes a reactor 22 and two switching elements 24 and 26. The voltage converter 20 is a circuit having a function of boosting a low voltage of about 200 V to about 300 V on the power storage device 14 side to a high voltage of, for example, about 600 V using the energy storage action of the reactor 22. Also called. In addition, the voltage converter 20 has a bidirectional function, and when the power from the first inverter 36 and the second inverter 38 constituting the inverter unit 34 is supplied to the power storage device 14 side as charging power, The high voltage on the side of the first inverter 36 and the second inverter 38 is also lowered to a low voltage suitable for the power storage device 14.

  Reactor 22 is a device that has one end connected to a positive electrode bus on the side of power storage device 14 and the other end connected to a connection point between two switching elements 24 and 26, and can store magnetic energy. The reactor 22 is used as an inductance by winding a coil around a magnetic core and passing a high-frequency signal through the coil. The reactor 22 can be used together with the switching elements 24 and 26 to constitute a step-up / step-down circuit. . When a high frequency signal is passed through the coil, the core and the coil generate heat. For example, the temperature may rise from about 100 ° C. to about 200 ° C.

The temperature sensor 28 disposed in the vicinity of the reactor 22 is a temperature detection element having a function of detecting the temperature θ _{1 of the} reactor 22 and transmitting the detection result to the control unit 60 via an appropriate signal line.

  The two switching elements 24 and 26 are high power switching transistors connected in series with each other and disposed between the positive and negative buses of the inverter unit 34. The connection point between the two switching elements 24 and 26 is connected to the other end of the reactor 22 as described above. As the switching elements 24 and 26, gate-insulated bipolar transistors (IGBT) can be used. In FIG. 1, the switching elements 24 and 26 are shown as n-channel type, but may be p-channel type due to voltage. A diode is connected to each of the two switching elements 24 and 26 in parallel.

  Of the two switching elements 24 and 26, the switching element 24 on one side has a collector terminal connected to the positive electrode bus of the inverter unit 34, an emitter terminal connected to the collector terminal of the switching element 26 on the other side, and a gate terminal. The control terminal is connected to a control signal line from the control unit 60. As described above, the switching terminal 26 on the other side has the collector terminal connected to the emitter terminal of the switching element 24 on one side, the emitter terminal connected to the negative electrode bus common to the power storage device 14 and the inverter unit 34, and the gate terminal The control terminal is connected to a control signal line from the control unit 60.

  The voltage converter 20 performs step-up and step-down operations as follows under the control of the switching elements 24 and 26. In the step-up operation, power is supplied from the inverter unit 34 side to the power storage device 14 side, and in the step-down operation, power is supplied from the power storage device 14 side to the inverter unit 34 side.

In the case of the boosting operation, the switching element 24 is turned off and the switching element 26 is turned on. As a result, the connection with the inverter unit 34 is opened. On the other hand, since the other end of reactor 22 is connected to the negative electrode bus, a current flows from the positive electrode bus of power storage device 14 to negative electrode bus through reactor 22. As described above, since current flows into the reactor 22 from the power storage device 14, energy of (LI ² ) / 2 is accumulated in the reactor 22, where I is the current and L is the impedance of the reactor. As a result, the voltage at the other end of the reactor 22 rises, and when the difference from the voltage on the inverter unit 34 side becomes more than a certain level due to the action of the diode connected in parallel to the switching element 24, the energy of the inverter unit 34 is increased. Flows into the side. As a result, the voltage of the smoothing capacitor 30 on the inverter side gradually increases. In this manner, the voltage between the positive electrode bus and the negative electrode bus of the inverter unit 34 is increased and the voltage is boosted.

  In the case of the step-down operation, the switching element 26 is turned off and the switching element 24 is turned on, contrary to the step-up operation. As a result, the connection between the reactor 22 and the negative electrode bus is opened. On the other hand, since the positive bus of inverter unit 34 is connected to the other end of reactor 22, the energy accumulated in inverter-side smoothing capacitor 30 flows into reactor 22 and enters smoothing capacitor 18 on the side of power storage device 14. Transferred. In this way, the power on the inverter unit 34 side is stepped down and supplied to the power storage device 14 side.

The inverter-side smoothing capacitor 30 provided between the voltage converter 20 and the inverter unit 34 is a capacitor having a function of suppressing voltage fluctuation on the high voltage side. Although V _H is shown in FIG. 1 as the voltage across the smoothing capacitor 30, this V _H is the voltage on the high voltage side of the voltage converter 20. The discharge resistor 32 is a resistance element that is used when the operation of the power supply circuit 12 stops and the electrical energy accumulated in the smoothing capacitor 30 needs to be discharged.

  The inverter unit 34 includes two inverters 36 and 38. The two inverters 36 and 38 both convert high-voltage DC power into AC three-phase drive power and supply it to the rotating electrical machines connected thereto, and conversely, AC three-phase regenerative power from each rotating electrical machine. Is a circuit having a function of converting the power into high-voltage DC charging power. Of the two inverters 36 and 38, the one connected to the first rotating electric machine (MG1) 6 is the second one connected to the first rotating electric machine (MG1 inverter) 36 and the second rotating electric machine (MG2) 8 is the second. Inverter (MG2 inverter) 38.

  The inverters 36 and 38 have the same basic configuration, and include a plurality of switching elements and a plurality of diodes. The switching element is a high-power switching transistor similar to the switching elements 24 and 26 in the voltage converter 20, and an IGBT or the like can be used. Since these switching elements perform high-power switching, they generate heat during operation and the temperature rises.

  The inverter cooling system 40 is a cooling system for cooling the inverter unit 34. In FIG. 1, the voltage converter 20 is also cooled together with the inverter unit 34, but this is a high voltage system from the voltage converter 20 to the inverter unit 34 as one PCU (Power Control Unit). This is because they are often collected and stored in one unit case. In that sense, the inverter cooling system 40 can be said to be a cooling system for a power unit including an inverter.

  The inverter cooling system 40 circulates a coolant such as cooling water along the coolant circulation flow path 44 by the circulation pump 42, carries heat away from the inverters 36 and 38 and the voltage converter 20, and dissipates heat to the outside by an appropriate radiator 46. Cooling system.

The temperature sensor 48 disposed in the vicinity of the refrigerant circulation flow path has a function of detecting the temperature θ ₂ of the coolant that is the refrigerant and transmitting the detection result to the control unit 60 via an appropriate signal line. It is an element.

The low voltage operation auxiliary machine 50 is an electric device or the like that is operated by the voltage V _L on the low voltage side of the voltage converter 20. In FIG. 1, a DC / DC converter 52 that converts low voltage power having V _L to DC power of about 12V and supplies the DC power to a 12V battery 54, and an air conditioning ECU (A / C-ECU) that operates at a voltage of 12V 56 and an air conditioning inverter (A / C inverter) 58 that operates at _VL and controls the operation of the air conditioning compressor (COMP) 4 are shown.

  The control unit 60 is a control circuit having a function of controlling the operation of each element constituting the power supply circuit 12 as a whole. The control unit 60 operates under the instruction of an integrated control unit that controls traveling of the vehicle (not shown). Here, the control unit 60 has a function of performing control to suppress an excessive temperature rise of the inverter unit 34 and the voltage converter 20 particularly when a problem occurs in the inverter cooling system 40. Such a control unit 60 can be configured by a computer suitable for mounting on a vehicle. This may be an independent computer, and the function of the control unit 60 may be included as part of the function of another control device mounted on the vehicle. For example, the function of the control unit 60 may be included in the overall control unit.

The control unit 60 acquires the state of the inverter cooling system 40 and determines whether the state is normal or abnormal, and an input brought into the power storage device 14 when the inverter cooling system is abnormal. When the power storage device W _IN , W _OUT limiting module 64 that limits the power W _IN and the output power W _OUT taken out and the inverter cooling system 40 are abnormal, the output of the low-voltage operation auxiliary device 50 is limited. An auxiliary machine output limiting module 66 is included. Each of these functions is realized by software, and specifically can be realized by executing a power supply control program. Some of these functions may be realized by hardware.

  The operation of the above configuration, in particular, each function of the control unit 60 will be described in detail with reference to FIGS. FIG. 2 is a flowchart showing a processing procedure when there is an abnormality in the inverter cooling system 40, FIG. 3 is a diagram for explaining a state of load factor limitation of the power storage device 14, and FIG. 4 is an output of the low-voltage operation auxiliary machine 50 FIG. 5 is a diagram for explaining the switching of the restriction map, and FIG. 5 is a diagram for explaining the relationship between the load factor of the low-voltage operating auxiliary machine 50 and the temperature of the reactor 22. Each procedure in the flowchart of FIG. 2 corresponds to each processing procedure of the power supply control program.

When the power supply control program is started, the state of the inverter cooling system 40 is acquired (S10). This step is executed by the function of the inverter cooling system state acquisition module 62 of the control unit 60. Specifically, the temperature sensor 48 detects the temperature θ ₂ of the cooling water that is the refrigerant of the inverter cooling system 40, and the control unit 60 acquires the detection result.

Then, it is determined whether the inverter cooling system 40 is normal or abnormal (S12). As a criterion for determining whether the temperature is normal or abnormal, the temperature θ ₂ detected by the temperature sensor 48 is compared with a predetermined threshold temperature, and the state of the inverter cooling system 40 is detected when the detected temperature θ ₂ exceeds the threshold temperature. Can be determined to be abnormal.

When the inverter cooling system 40 is in an abnormal state, the inverters 36 and 38 are abnormally heated due to an overload or the like, and the inverters 36 and 38 are operating normally, but the inverter cooling system 40 is configured. A failure may occur in the element, and the inverter unit 34 may not be cooled normally. In either case, as a result, the temperature of the cooling water that is the refrigerant rises, so that the abnormality of the inverter cooling system 40 can be detected by monitoring the temperature θ ₂ of the temperature sensor 48. In order to detect an abnormality more quickly, it is desirable to directly detect a failure of an element constituting the inverter cooling system 40.

  Therefore, it is desirable to determine the state of the inverter cooling system 40 in consideration of whether the rotation speed of the circulation pump 42 is normal or abnormal, whether the rotation speed of the radiator 46 is normal or abnormal, and the like. For example, the rotational speed information of the circulation pump 42 is transmitted to the control unit 60 through an appropriate signal line, and the rotational speed information is compared with a predetermined threshold rotational speed to determine whether the inverter cooling system 40 is normal or abnormal. I can do it.

If it is determined in S12 that the state of the inverter cooling system 40 is abnormal, next, the input power W _IN brought into the power storage device 14 and the output power W _OUT taken out are limited. (S14). This process is executed by the function of the W _IN and W _OUT limiting module 64 of the power storage device of the control unit 60. When there is no other device that consumes power between the power storage device 14 and the reactor 22 or when there is little power consumption, the reactor 22 is limited by limiting W _IN and W _OUT of the power storage device 14. Can be effectively suppressed, whereby the reactor 22 can be prevented from generating heat and rising in temperature.

The limitation on W _IN and W _OUT of the power storage device 14 can be performed using the load factor limitation map of the power storage device 14 according to the temperature θ _{1 of the} reactor 22. FIG. 3 is a diagram showing the situation. The horizontal axis represents the temperature θ _{1 of the} reactor 22, and the vertical axis represents the normalized amount of W _IN or W _OUT of the power storage device. The normalized value of W _IN or W _OUT is ₁ when the temperature θ _{1 of the} reactor 22 is sufficiently low, and for an arbitrary temperature, the ratio to 1 is shown as the load factor. In FIG. 3, the load factor limiting characteristic when the inverter cooling system 40 is normal is indicated by a solid line, and the load factor limiting characteristic when the inverter cooling system 40 is abnormal is indicated by a broken line.

For the inverter cooling system 40 is normal, the load factor = 1 at low temperature theta ₁ is less than or equal to B ° C. Reactor 22, W _IN or W _OUT limitations of the power storage device is not performed. When the temperature θ _{1 of the} reactor 22 is equal to or higher than B ° C., the load factor of the power storage device is limited to be smaller than 1 as the temperature θ _{1 of the} reactor 22 increases. That is, W _IN and W _OUT are limited to be small.

  When the inverter cooling system 40 is abnormal, the temperature of the reactor 22 at which the load factor of the power storage device 14 begins to be limited is set to a temperature A ° C. which is lower than the normal temperature B ° C. For example, B = 110 ° C. and A = 100 ° C. is set. That is, when the inverter cooling system 40 is determined to be abnormal, the load factor limitation of the power storage device 14 is started at a lower temperature side. As a result, the restriction of the current flowing through the reactor 22 is started on the lower temperature side than in the normal state, and the heat generation and temperature rise of the reactor 22 can be suppressed.

Returning to FIG. 2 again, after S14, the output of the auxiliary machine operating at a low voltage is limited. This restriction is performed by switching an auxiliary machine output restriction map indicating the relationship between the temperature θ ₁ of the reactor 22 and the auxiliary machine output upper limit value (S16). FIG. 4 shows how the auxiliary machine output restriction map is switched. In FIG. 4, an arbitrary parameter other than the temperature of the reactor 22 is taken on the horizontal axis, and an example of the upper limit value of the auxiliary machine output corresponding to the temperature θ _{1 of the} reactor 22 is shown on the vertical axis.

Here, as an example, an auxiliary machine output limit map showing the upper limit value of the auxiliary machine output when the inverter cooling system 40 is normal is shown by a solid line, and the upper limit value of the auxiliary machine output when the inverter cooling system 40 is abnormal is shown. The auxiliary machine output restriction map shown is indicated by a broken line. That is, the auxiliary machine output limit map when the inverter cooling system 40 is normal has an auxiliary machine output upper limit value P ₀ , whereas the auxiliary machine output limit map when the inverter cooling system 40 is abnormal is an auxiliary machine output limit map. The upper limit value of the machine output is set to αP ₀ . α indicates a load factor of the auxiliary machine and is a number of 1 or less. α can be set to a different value depending on the temperature of the reactor 22. In FIG. 4, in order to show that, when the upper limit value of the auxiliary machine output is P ₀ , when θ ₁ = 65 ° C. and θ ₁ = 85 ° C., the upper limit value of the auxiliary machine output becomes 0.5P _0. As a thing.

FIG. 5 is a diagram showing the relationship between the temperature θ ₁ of the reactor 22 and the auxiliary machine load factor α. As shown by the solid line, the auxiliary machine load factor α takes α = 1 when the temperature θ _{1 of the} reactor 22 is a low temperature equal to or lower than the threshold temperature D ° C. When the threshold temperature exceeds D ° C., it takes a value of 1 or less as indicated by the broken line. In FIG. 5, in accordance with the example of FIG. 4, it is assumed that α = 0.5, but of course other values can be set. Thus, α is discontinuously switched from 1 to a small value other than the threshold temperature D ° C.

In FIG. 5, as another method for setting the auxiliary machine load factor α, an example in which the auxiliary load factor α is set to a continuously small value from ₁ in accordance with the temperature θ ₁ of the reactor 22 is indicated by a one-dot chain line. Here, another threshold temperature C ° C. is provided. When the temperature θ _{1 of the} reactor 22 is a low temperature of C ° C. or lower, α = 1, and when the temperature exceeds the threshold temperature D ° C., for example, α = 0.5 Take. And between C degrees C and D degrees C, auxiliary machinery load factor alpha takes the value which changes continuously from alpha = 1 to alpha = 0.5 according to temperature theta _{1 of} reactor 22. In FIG.

Returning to FIG. 2 again, when the auxiliary machine output restriction map is switched according to the temperature θ ₁ of the reactor 22 in S16, the output of each auxiliary machine is restricted according to the switching. In FIG. 2, the output restriction of the DC / DC converter 52 is executed according to the configuration of FIG. 1 (S18), and the output restriction of the air conditioning inverter 58 is executed (S20). For example, in the above example, when it is determined that the state of the inverter cooling system 40 is abnormal and the temperature of the reactor 22 exceeds the threshold temperature D ° C., the output of the DC / DC converter 52 is limited to 50%, and the air conditioning The output of inverter 58 is limited to 50%. Steps S <b> 16, S <b> 18 and S <b> 20 are executed by the function of the auxiliary machine output restriction module 66 of the control unit 60. After the process of S20, the process returns to S10 again, and the above processing procedure is repeated. If the determination is negative in S12, the process returns to S10 in the same manner.

As described above, when it is determined that the state of the inverter cooling system 40 is abnormal, the output of the low-voltage operation auxiliary machine 50 is restricted along with the restriction of W _IN and W _OUT of the power storage device 14 as follows. This is because there are cases. That is, when an abnormality occurs in the inverter cooling system 40, when the temperature of the inverter rises, generally, the drive output of the rotating electrical machines 6 and 8, which are loads, or regenerative power is limited. The operating power of the inverters 36 and 38 can be suppressed. Further, when the temperature of the voltage converter 20 rises accordingly, W _IN and W _OUT that are input / output power to the power storage device 14 can be limited, and the power flowing through the voltage converter 20 can be limited.

However, when the low voltage operation auxiliary machine 50 is connected between the power storage device 14 and the voltage converter 20 as in the configuration described in FIG. 1, if W _IN and W _OUT of the power storage device 14 are limited, It may occur that the power supplied to the low-voltage operating accessory 50 is insufficient for the operating power. At this time, power is supplied from the high-voltage side inverters 36 and 38 via the voltage converter 20 in order to compensate for the insufficient power. That is, the inverters 36 and 38 perform the corresponding operation, and a current also flows through the reactor 22 of the voltage converter 20. As described above, although the W _IN and W _OUT of the power storage device 14 are limited, the temperatures of the inverters 36 and 38 may increase and the temperature of the reactor 22 may also increase.

Therefore, when it is determined that the state of the inverter cooling system 40 is abnormal, W _IN and W _OUT of the power storage device 14 are restricted, and the output of the low-voltage operation auxiliary machine 50 is restricted. Therefore, the temperature rise of the inverters 36 and 38 can also be suppressed. Then, by limiting the output of the low-voltage operation auxiliary machine 50 according to the temperature θ ₁ of the reactor 22, the temperature of the reactor 22 is prevented while preventing the output limit of the low-voltage operation auxiliary machine 50 from becoming excessive. The rise can be suppressed.

It is a figure which shows the structure of the power supply control system of embodiment which concerns on this invention. In embodiment which concerns on this invention, it is a flowchart which shows the process sequence when there is abnormality in an inverter cooling system. In embodiment which concerns on this invention, it is a figure explaining the mode of the load factor restriction | limiting of an electrical storage apparatus. In embodiment which concerns on this invention, it is a figure explaining switching of the output restriction map of a low voltage operation | movement auxiliary machine. In embodiment which concerns on this invention, it is a figure explaining the relationship between the load factor of a low voltage operation | movement auxiliary machine, and the temperature of a reactor.

Explanation of symbols

4 Air-conditioning compressor, 6, 8 Rotating electric machine, 10 Power supply control system, 12 Power supply circuit, 14 Power storage device, 16 System main relay, 18, 30 Smoothing capacitor, 20 Voltage converter, 22 Reactor, 24, 26 Switching element, 28 , 48 Temperature sensor, 32 Discharge resistance, 34 Inverter unit, 36, 38 Inverter, 40 Inverter cooling system, 42 Circulation pump, 44 Refrigerant circulation flow path, 46 Radiator, 50 Low voltage operation auxiliary machine, 52 DC / DC converter, 54 Battery, 56 Air conditioning ECU, 58 Air conditioning inverter, 60 Control unit, 62 Inverter cooling system state acquisition module, 64 Power storage device W _IN , W _OUT limiting module, 66 Auxiliary machine output limiting module

Claims (4)

A voltage converter including a reactor and capable of stepping up and down between a low voltage and a high voltage;
An inverter connected between a load operating with high-voltage AC power and a voltage converter;
Auxiliary machine output limiting means for limiting the output of the auxiliary machine according to the temperature of the reactor, with respect to the auxiliary machine connected in parallel between the low voltage power storage device and the voltage converter, and operating with low voltage power,
A power supply control system comprising: The power supply control system according to claim 1,
Means for acquiring the state of the inverter cooling system;
Auxiliary machine output limiting means
A power supply control system that limits the output of the auxiliary machine according to the state of the inverter cooling system. The power supply control system according to claim 1,
A power supply control system comprising power storage device input / output limiting means for limiting input power and output power to a low voltage power storage device according to a temperature of a reactor. The power supply control system according to claim 1,
The power supply control system, wherein the auxiliary machine is a DC / DC converter or an air compressor.

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