JP6722058B2 - Power system controller - Google Patents

Description

The present invention relates to a control device for a power supply system including an open/close switch.

In a hybrid vehicle equipped with a traveling motor, an inverter connected to the motor, a main battery connected to the inverter, and an SMR (System Main Relay) electrically connecting or disconnecting the inverter and the main battery, And a capacitor connected between the DC voltage side terminals of the inverter. In such a hybrid vehicle, generally, a precharge relay in which precharge resistors for suppressing inrush current are connected in series and an SMR in which a precharge resistor is not connected are provided in parallel to start a vehicle. At times, the precharge relay is turned on to precharge the capacitor, and then the SMR is turned on to prevent the SMR from being damaged by a large current.

In addition, even in a hybrid vehicle or the like, an auxiliary machine is mounted similarly to a vehicle using only an engine as a drive source, and electric power is supplied to the auxiliary machine from an auxiliary machine battery whose output voltage is lower than that of the main battery. In a hybrid vehicle equipped with such an auxiliary battery, a bidirectional DC/DC converter or a DC/DC converter for converting low voltage to high voltage is provided between the main battery and the auxiliary battery. Sometimes. When such a DC/DC converter is provided, precharging the capacitor using the DC/DC converter can reduce the number of precharge relays. In this case, damage to the SMR can be prevented by setting the main battery voltage as the target voltage in the precharge and turning on the SMR after completing the precharge. However, depending on the detection error of the voltage sensor that detects the voltage and the accuracy of the output voltage of the DC/DC converter, there is a difference between the main battery voltage and the capacitor voltage after the completion of precharge, which causes a large difference when the SMR is turned on. Electric current may flow. In this case, there is a difference in the capacitor voltage immediately before the SMR is turned on and immediately after the SMR is turned on.

Therefore, the control device of the power supply circuit described in Patent Document 1 detects the capacitor voltage immediately before the SMR is turned on after the completion of precharge and the capacitor voltage immediately after the SMR is turned on, and detects the capacitor voltage immediately before and after the SMR. The difference is stored as a correction value. Then, the control device corrects the target voltage in the next precharge with the stored correction value to suppress the difference between the main battery voltage and the capacitor voltage after the completion of precharge. As a result, a large current is suppressed from flowing in the SMR.

JP, 2007-209114, A

The control device described in Patent Document 1 needs to store the correction value until the next precharge. Therefore, it is necessary to add a memory circuit for storing the correction value. Further, when the detection error changes depending on the usage environment such as temperature, there is a possibility that the target voltage cannot be corrected with high accuracy even if the correction is performed based on the correction value updated last time.

In view of the above situation, it is a main object of the present invention to provide a control device for a power supply system that can suppress damage to the open/close switch with simple control while using a general circuit.

A first configuration includes a main power storage device (10), a smoothing capacitor (60), and the smoothing capacitor, and a boosting circuit (50) that boosts a voltage on the main power storage device side and outputs the voltage to the smoothing capacitor side. And a controller (90) for a power supply system, which is applied to a power supply system (80) including: an open/close switch (71, 72) that electrically connects or disconnects the main power storage device and the booster circuit. The power supply system is connected to a connecting portion between the open/close switch and the booster circuit, and outputs a voltage higher than that of the main power storage device before switching the open/close switch from a disconnection state to a connection state; A regulating element that does not regulate the flow of current from the switch side to the smoothing capacitor side and regulates the flow of current from the smoothing capacitor side to the open/close switch side; and Before switching to the connected state, a precharge unit that supplies electric power from the voltage source to the smoothing capacitor to precharge the smoothing capacitor is provided.

According to the first configuration, when the open/close switch is turned off and the smoothing capacitor is precharged, power is supplied from the voltage source to the smoothing capacitor via the regulation element. The voltage source outputs a voltage higher than that of the main power storage device before switching the open/close switch from the disconnection state to the connection state. Therefore, by precharging, the voltage of the smoothing capacitor can be made higher than that of the main power storage device before the switching of the open/close switch from the disconnected state to the connected state. Here, even when the voltage of the smoothing capacitor is set to a voltage higher than that of the main power storage device before the switching of the on/off switch from the disconnection state to the connection state, the discharge from the smoothing capacitor to the on/off switch is suppressed by the regulation element. .. Therefore, both a large current flowing from the main power storage device to the smoothing capacitor and a large current flowing from the smoothing capacitor to the main power storage device can be suppressed, and damage to the open/close switch can be suppressed by simple control. ..

A second configuration includes a main power storage device (10), a sub power storage device (20) having a lower voltage than the main power storage device, a smoothing capacitor (60), and the smoothing capacitor, and a voltage on the main power storage device side. A booster circuit (50) for boosting and outputting the voltage to the smoothing capacitor side, an open/close switch (71, 72) for electrically connecting or disconnecting the main power storage device and the booster circuit, the open/close switch and the booster A power supply system (80) including a DC/DC converter (30) that is connected between a connection portion with a circuit and the sub power storage device, and that converts and outputs a voltage of electric power stored in the sub power storage device. (90) for a power supply system, wherein the booster circuit does not regulate the flow of current from the opening/closing switch side to the smoothing capacitor side, and the smoothing capacitor side to the opening/closing switch side. Has a regulation element that regulates the flow of current to the smoothing capacitor by supplying power from the DC/DC converter to the smoothing capacitor before switching the open/close switch from the disconnection state to the connection state. And a voltage setting unit that sets a target voltage in precharging of the smoothing capacitor to a value higher than the detection voltage of the main power storage device by a predetermined voltage, and a detection voltage of the smoothing capacitor becomes the target voltage. An energizing section that brings the open/close switch into a connected state after it is determined that the switch has arrived.

According to the second configuration, when the open/close switch is turned off and the smoothing capacitor is precharged, the voltage of the electric power stored in the sub power storage device is converted by the DC/DC converter, and the DC/DC converter boosts the voltage. Power is supplied to the smoothing capacitor via the. At this time, the target voltage in the precharge is set to a value higher by a predetermined voltage than the detected voltage of the main power storage device. Then, after it is determined that the detected voltage of the smoothing capacitor has reached the target voltage, the open/close switch is brought into the connected state.

Here, if the deviation between the voltage of the main power storage device and the voltage of the smoothing capacitor after precharging is within the permissible deviation, when the open/close switch is connected, switching from the smoothing capacitor or from the main power storage device is performed. A large current is suppressed from flowing to the switch, and damage to the open/close switch is prevented. However, due to the detection error of the detection voltage of the main power storage device and the detection error of the detection voltage of the smoothing capacitor, it is difficult to keep the above deviation within the allowable deviation. In order to keep the above deviation within the allowable deviation, it is necessary to make the detection error sufficiently small. That is, as compared with the case of using a precharge relay in which the precharge resistance naturally adjusts the voltage, when adjusting the voltage with the detection voltage as a target, a voltage sensor that detects the voltage of the main power storage device or a smoothing capacitor It is desired to make the voltage sensor for detecting the voltage of 1) highly accurate. However, increasing the accuracy of the voltage sensor increases the cost.

In this regard, if the target voltage is set to a value higher than the detection voltage of the main power storage device by a predetermined voltage, and if the detection voltage tends to be lower than the true voltage, the true voltage of the smoothing capacitor is higher than the target voltage. Since it is also low, it is easy to keep the above deviation within the allowable deviation. On the other hand, when the detected voltage tends to be higher than the true voltage, the true voltage of the smoothing capacitor becomes higher than the target voltage, and therefore the deviation is likely to be larger than when it tends to be low. However, the discharge from the smoothing capacitor to the open/close switch is suppressed by the regulating element. Therefore, a relatively large value is allowed for the deviation on the side where the voltage of the smoothing capacitor is high with respect to the voltage of the main power storage device, compared to the deviation on the side where the voltage of the smoothing capacitor is low. Therefore, by setting the target voltage to a value higher by a predetermined voltage than the detection voltage of the main power storage device, even if a detection error occurs on either the higher side or the lower side, the above deviation falls within the allowable deviation. Can be made easier. Moreover, the regulating element is usually provided in the booster circuit. Therefore, damage to the open/close switch can be suppressed by simple control while using a general circuit of the power supply system.

The figure which shows the structure of the power supply system which concerns on this embodiment. The figure which shows the detection error of voltage, an allowable deviation, and the relationship of target voltage. The flowchart which shows the process sequence which implements precharge. The figure which shows the structure of the power supply system which concerns on a modification. The figure which shows the structure of the power supply system which concerns on a modification. The figure which shows the structure of the power supply system which concerns on a modification. The figure which shows the structure of the power supply system which concerns on a modification.

Hereinafter, an embodiment that embodies a control device for a power supply system will be described with reference to the drawings. The power supply system according to the present embodiment is assumed to be a power supply system mounted on a vehicle including a traveling motor such as a hybrid vehicle or an electric vehicle.

First, the configuration of the power supply system according to the present embodiment will be described with reference to FIG. The power supply system 80 according to this embodiment includes a main battery 10, an auxiliary battery 20, a DC/DC converter 30, a booster circuit 50, SMRs 71, 72, and voltage sensors 81, 82, 83. Power supply system 80 is connected to MG1 via first inverter 200 and is connected to MG2 via second inverter 400.

In the power supply system 80, the main battery 10 is connected to the booster circuit 50 via the SMRs 71 and 72, and the smoothing capacitor 60 on the output side of the booster circuit 50 has the first inverter 200 and the second inverter 400 in parallel, respectively. It is connected to the. A DC/DC converter 30 is connected between the connection between the SMRs 71 and 72 and the booster circuit 50 and the auxiliary battery 20. The DC/DC converter 30 is connected in parallel to the filter capacitor 40 on the input side of the booster circuit 50.

The main battery 10 is a high-voltage assembled battery in which a plurality of battery cells are connected in series, and its rated output voltage is, for example, 200 to 300V. As the main battery 10, for example, a lithium ion battery, a nickel hydrogen battery, or the like can be adopted. Main battery 10 exchanges electric power with MG1 and MG2 mainly through first inverter 200 and second inverter 400. The main battery 10 corresponds to the main power storage device.

The auxiliary battery 20 is a low-voltage battery whose rated output voltage is lower than that of the main battery 10, and is, for example, a lead storage battery. Auxiliary battery 20 is connected to load 100 mounted on the vehicle, and mainly supplies power to load 100. The load 100 is an electric device mounted on the vehicle, and is, for example, an ECU, a headlight, an audio, an air conditioner, a power window, or the like. The auxiliary battery 20 corresponds to a sub power storage device.

The DC/DC converter 30 is a circuit that converts the voltage of the electric power stored in the auxiliary battery 20 into a predetermined voltage and outputs the voltage. Specifically, the DC/DC converter 30 boosts the voltage of the electric power stored in the auxiliary battery 20 and supplies the voltage to the smoothing capacitor 60 and the main battery 10, and the electric power stored in the smoothing capacitor 60 and the main battery 10. Is a bidirectional converter for stepping down the voltage of and supplying it to the auxiliary battery 20. Alternatively, DC/DC converter 30 may be a unidirectional converter that boosts the voltage of the electric power stored in auxiliary battery 20 and supplies the voltage to smoothing capacitor 60 or main battery 10.

The booster circuit 50 is a circuit that boosts the voltage of the electric power stored in the main battery 10 or the output voltage of the DC/DC converter 30 to a predetermined voltage and supplies the boosted voltage to the first inverter 200 and the second inverter 400. The booster circuit 50 according to this embodiment is a booster chopper circuit, and includes a filter capacitor 40, a coil 51, switching elements 52 and 53, diodes 54 and 55, and a smoothing capacitor 60. The switching elements 52 and 53 are, for example, IGBTs, and the diodes 54 and 55 are connected to the switching elements 52 and 53 in antiparallel. The diode 54 corresponds to a regulating element.

The filter capacitor 40 is a capacitor that stabilizes the input voltage of the booster circuit 50. The smoothing capacitor 60 is a capacitor that smoothes the DC voltage of the first inverter 200 and the second inverter 400. The voltage smoothed by the smoothing capacitor 60 is input to the first inverter 200, the second inverter 400, and the bridge circuit of the booster circuit 50. Generally, the capacity of the smoothing capacitor 60 is larger than the capacity of the filter capacitor 40, and is several times as large as the capacity of the filter capacitor 40.

The SMRs 71 and 72 are open/close switches that electrically connect or disconnect the main battery 10 and the booster circuit 50. The SMRs 71 and 72 are relays that close the contacts when an exciting current is applied to the coils. Here, the state where the contacts of the SMRs 71 and 72 are closed is referred to as ON, and the state where the contacts are opened is referred to as OFF. The main battery 10 and the booster circuit 50 are electrically connected when the SMRs 71 and 72 are on, and the main battery 10 and the booster circuit 50 are electrically disconnected when the SMRs 71 and 72 are off. The SMR 71 is arranged between the positive electrode side of the main battery 10 and the coil 51 of the booster circuit 50, and the SMR 72 is arranged between the negative electrode side of the main battery 10 and the booster circuit 50.

The voltage sensor 81 is connected in parallel to the main battery 10 and detects the voltage VB of the main battery 10. The voltage sensor 82 is connected in parallel to the filter capacitor 40 and detects the voltage VL between the terminals of the filter capacitor 40. The ECU 90 takes in the detected voltage detected by the voltage sensor 81 and the voltage sensor 82. The voltage sensor 83 is connected in parallel with the smoothing capacitor 60 and detects the voltage VH across the terminals of the smoothing capacitor 60. However, the ECU 90 cannot take in the voltage VH detected by the voltage sensor 83 on the high voltage side of the booster circuit 50 unless communication is performed. Here, during the precharge, the booster circuit 50 does not operate, and the voltage VL between the terminals of the filter capacitor 40 becomes substantially equal to the voltage VH between the terminals of the smoothing capacitor 60. Therefore, during the precharge, the voltage VL is detected as the voltage VH, and the ECU 90 uses the voltage VL detected by the voltage sensor 82 as the voltage VH. The ECU 90 may receive the voltage VH detected by the voltage sensor 83 through communication and use the voltage VH detected by the voltage sensor 83.

The voltage VB of the main battery 10 needs to be detected with relatively high accuracy for the safety of the user. On the other hand, the voltage VL and the voltage VH do not need to be detected as accurately as the voltage VB for the purpose of controlling the DC/DC converter 30, the first inverter 200, and the second inverter 400. Therefore, as shown in FIG. 2, the voltage sensors 82 and 83 are detection circuits having a larger detection error than the voltage sensor 81. The detection error of each of the voltage sensors 81, 82, 83 is relatively small in the detection range assumed as the voltage to be detected, but the detection error is relatively large outside the assumed detection range. ..

The first inverter 200 and the second inverter 400 are three-phase power conversion circuits including six switching elements. The first inverter 200 and the second inverter 400 convert the DC power supplied via the smoothing capacitor 60 into AC power and supply the AC power to MG1 and MG2, respectively, and the AC power supplied from the MG1 and MG2 to DC. It is converted into electric power and supplied to the smoothing capacitor 60.

MG1 and MG2 according to the present embodiment are three-phase motor generators. MG1 is a motor generator that mainly functions as a generator, and MG2 is a motor generator that mainly functions as an electric motor and serves as a travel drive source of the vehicle.
The ECU 90 (control device for power supply system) is mainly composed of a microcomputer including a CPU, a ROM, a RAM, an I/O, a storage device, and the like. The ECU 90 issues an on/off command to the SMRs 71 and 72 and an operation command to the DC/DC converter 30 and the booster circuit 50. For details, in the ROM which is a non-transitional practical recording medium such as a semiconductor memory, the power supply system 80 A program for realizing various functions for controlling is stored. The CPU realizes various functions by controlling the power supply system 80 by executing the programs stored in the ROM. The ECU 90 realizes the functions of the precharge unit, the voltage setting unit, the discharging unit, and the energizing unit, and includes various maps. Hereinafter, each function of the ECU 90 will be described.

First, the relationship between the operating states of the SMRs 71 and 72 and the position of the start switch will be described. The start switch is an ignition switch or a push-type start switch. The start switch has, for example, an off position, an ACC position, an on position, and a start position. The position of the start switch is switched in the order of off position→ACC position→on position→start position, and the start position is automatically returned to the on position. The ECU 90 turns off the SMRs 71 and 72 when the power is cut off, that is, when the position of the start switch is in the off position. Further, when the power source is connected, that is, when the position of the start switch is switched from the off position to the start position via the ACC position and the on position, the ECU 90 first precharges the smoothing capacitor 60 by the precharge unit. Then, when the voltage VH of the smoothing capacitor 60 reaches the target voltage and the precharge is completed, the ECU 90 turns the SMRs 71 and 72 from off to on to switch from the precharge mode to the normal mode.

Specifically, when the start switch is switched to the start position, the precharge unit causes the DC/DC converter 30 to perform a boosting operation with the SMRs 71 and 72 turned off before switching the SMRs 71 and 72 from off to on. Then, the precharge unit boosts the voltage of the auxiliary battery 20 and supplies it to the smoothing capacitor 60, and precharges the smoothing capacitor 60 to a target voltage described later. As a result, a current flows from the auxiliary battery 20 to the smoothing capacitor 60 via the DC/DC converter 30, the coil 51 of the booster circuit 50, and the diode 54, as shown by the chain line arrow in FIG. At this time, the precharge unit controls the operation of the DC/DC converter 30 so that the voltage of the smoothing capacitor 60 rises gently to prevent the generation of an inrush current. The booster circuit 50 is not operated during precharge.

The voltage setting unit sets a target voltage for precharging the smoothing capacitor 60 based on the detected value of the voltage VB of the main battery 10. Here, if the deviation ΔV between the voltage VB of the main battery 10 and the voltage VH after precharge is not within the allowable deviation, a large current flows through the SMR 71 when the SMRs 71 and 72 are turned on, The contacts of the SMR 71 may be damaged. Particularly, if such a state is repeated, the contacts of the SMR 71 may be damaged. The allowable deviation is such a value that when the deviation ΔV is contained within this allowable deviation, the current flowing through the SMR 71 becomes small when the SMRs 71 and 72 are turned from OFF to ON, without damaging the contacts of the SMR 71.

Therefore, it is desirable to make the deviation ΔV between the voltage VB and the voltage VH after precharge sufficiently small. However, there are detection errors of the voltage VB and the voltage VH. As shown in FIG. 2, assuming that the maximum detection error on the positive side of the voltage VB is ΔVB1, the maximum detection error on the negative side is ΔVB2, and the true value of the voltage VB is VBt, the detection of the voltage VB is detected. The voltage VBd has a value in the range of VBt−ΔVB2 to VBt+ΔVB1. When the detection voltage VB is the target voltage in precharge, the target voltage has a value in the range of VBt−ΔVB2 to VBt+ΔVB1.

Further, the maximum magnitude of the detection error on the positive side of the voltage VL, that is, the voltage VH is ΔVH1, and the maximum magnitude of the detection error on the negative side is ΔVH2. When the detection voltage VBt is set as the target value for precharge, the true value VHt of the voltage VH is a value in the range of VBt-ΔVB2-ΔVH2 to VBt+ΔVB1+ΔVH1. Therefore, the deviation ΔV between the true value VHt of the voltage VH and the true value VBt of the voltage VB is a value in the range of −(ΔVB2+ΔVH2) to ΔVB1+ΔVH1. The deviation ΔV on the positive side with respect to the true value VBt corresponds to a state in which the voltage VH is higher than the voltage VB.

The magnitude of the allowable deviation in consideration of the capacity of the smoothing capacitor 60 and the capacity of the filter capacitor 40 is B1 and B2 on the positive side and the negative side of the true value VBt of the voltage VB. As shown in FIG. 2, in order to make ΔVB1+ΔVH1, ΔVB2+ΔVH2 smaller than B1 and B2, it is necessary to configure a highly accurate detection circuit as compared with a power supply system using a precharge relay. Therefore, in order to prevent a large current from flowing through the SMR 71 when the SMRs 71 and 72 are turned on, the manufacturing cost for realizing the high precision detection circuit increases.

Here, when the SMRs 71 and 72 are turned on, if the true value VBt of the voltage VB is larger than the true value VHt of the voltage VH, current flows from the main battery 10 to the filter capacitor 40 and the smoothing capacitor 60. On the other hand, when the SMRs 71 and 72 are turned on and the true value VBt of the voltage VB is smaller than the true value VHt of the voltage VH, a current flows from the filter capacitor 40 to the main battery 10. In this case, the current from the smoothing capacitor 60 to the main battery 10 is suppressed by the diode 54. The diode 54 is a regulation element that does not regulate the flow of current from the SMR 71 side to the smoothing capacitor 60 side, but regulates the current flow from the smoothing capacitor 60 side to the SMR 71 side.

Therefore, the deviation ΔV on the side where the true value VHt is higher than the true value VBt is allowed to be larger than the deviation ΔV on the side where the true value VHt is lower than the true value VBt. As shown in FIG. 2, when the allowable deviation on the side where the true value VHt is higher than the true value VBt is A1 and the allowable deviation on the side where the true value VHt is lower than the true value VBt is A2, A1> It can be A2. In this case, the range of VBt-A2 to VBt+A1 is the allowable range of the true value VHt after precharge. If the true value VHt after precharging is a value within this allowable range, it is possible to suppress a large current from flowing through the SMR 71 when the SMRs 71 and 72 are turned on.

Therefore, the voltage setting unit sets the target voltage in the precharge to a value higher than the detected value of the voltage VB by the predetermined voltage ΔVS. In this case, the target voltage has a value in the range of VBt+ΔVS−ΔVB2 to VBt+ΔVS+ΔVB1. The true value VHt of the voltage VH is a value in the range of VBt+ΔVS-ΔVB2-ΔVH2 to VBt+ΔVS+ΔVB1+ΔVH1.

At this time, the voltage setting unit sets the predetermined voltage ΔVS as follows. That is, in the voltage setting unit, the lower limit of the value in which the detection error of the predetermined voltage ΔVS, the voltage VB, and the voltage VH is added to the true value VBd of the voltage VB is higher than the lower limit of the allowable range of the voltage VH. Thus, the predetermined voltage ΔVS is set. The lower limit of the value obtained by adding the detection error of the predetermined voltage ΔVS, the voltage VB, and the voltage VH to the true value VBt of the voltage VB is the lower limit of the true value VHt of the voltage VH after the end of precharge, It becomes VBd+ΔVS−ΔVB2-ΔVH2. On the other hand, the lower limit value of the allowable range of the voltage VH is a value in which the negative side allowable deviation A2 is added to the true value VBt, and is the true value VBt-A2. The voltage setting unit sets ΔVS so that VBt+ΔVS−ΔVB2-ΔVH2>VBt−A2. That is, ΔVS is set so that ΔVS>ΔVB2+ΔVH2-A2.

Further, the upper limit value that the true value VHt of the voltage VH can take is VBt+ΔVS+ΔVB1+ΔVH1, and the upper limit value of the allowable range of the voltage VH is VBt+A1. Therefore, the voltage setting unit sets VBt+A1>VBt+ΔVS+ΔVB1+ΔVH1. That is, ΔVS is set so that ΔVS<A1-ΔVB1-ΔVH1. As described above, since A1 can be set to a larger value than A2, normally, if ΔVS is set so that ΔVS>ΔVB2+ΔVH2-A2, ΔVS<A1-ΔVB1-ΔVH1 is satisfied.

At this time, the voltage setting unit calculates the detection error range −ΔVB2 to ΔVB1, −ΔVH2 to ΔVH1 and the allowable deviation range −A2 to A1 by using various maps prepared in advance. The ECU 90 includes, for example, a voltage corresponding error map and a voltage corresponding allowance map as various maps. The voltage correspondence error map is a map of the detection errors ΔVB1 and ΔVB2 of the voltage VB corresponding to the voltage VB or the voltage VH, and a map of the detection errors ΔVH1 and ΔVH2 of the voltage VH. Further, the voltage correspondence allowable map is a map showing allowable deviations A1 and A2 according to the voltage VB or the voltage VH. Note that the ECU 90 may use preset values as ΔVB2, ΔVB1, ΔVH2, ΔVH1, A2, A1 without providing various maps.

As described above, the voltage sensors 81 and 82 have different detection errors depending on whether they are within the range of the assumed detection voltage. Since the voltage VB and the voltage VH are approximately the same voltage, the voltage correspondence error map may correspond to either the voltage VB or the voltage VH. It is also conceivable that the current flowing through the SMR 71 changes when the SMRs 71 and 72 are switched from OFF to ON according to the voltage VB or the voltage VH. Therefore, a voltage correspondence allowance map is also prepared in advance. The voltage setting unit uses these maps to calculate the detection error range −ΔVB2 to ΔVB1, −ΔVH2 to ΔVH1 and the allowable deviation range −A2 to A1. The voltage setting unit may only calculate the detection error ΔVB2, the detection error ΔVH2, and the allowable deviation A2.

Alternatively, the ECU 90 may use, as various maps, a temperature-corresponding tolerance map indicating a tolerance deviation corresponding to the temperature in the usage environment of the power supply system 80 or a temperature-corresponding error map indicating a detection error of the voltage VB and the voltage VH corresponding to the temperature. You may have it. Generally, a temperature range suitable for use of the main battery 10 is fixed. When the main battery 10 is used in an appropriate temperature range, the allowable deviation A2 is relatively large and the detection error is relatively small, but the main battery 10 is used at a temperature outside the appropriate temperature range. In that case, the allowable deviation A2 becomes relatively small, and the detection error becomes relatively large.

Therefore, the voltage setting unit may calculate the allowable deviation range −A2 to A1 from the temperature corresponding allowable map, or may calculate the detection error range −ΔVB2 to ΔVB1, −ΔVH2 to ΔVH1 from the temperature corresponding error map. Good. Further, the ECU 90 includes an allowance map showing an allowance deviation according to the temperature and the voltage VB, or an allowance deviation showing the temperature and the voltage VH, and an error map showing a detection error, and the voltage setting unit has the allowance map and the error map. The allowable deviation and the detection error may be calculated from The temperature in the usage environment of the power supply system 80, particularly the temperature in the usage environment of the main battery 10, is detected by a temperature sensor (not shown).

Furthermore, the voltage setting unit may calculate the allowable deviation based on the capacity of the smoothing capacitor 60. The larger the capacity of the smoothing capacitor 60, the smaller the allowable deviation. Then, the capacity of the smoothing capacitor 60 becomes smaller as the smoothing capacitor 60 deteriorates over time. Therefore, the voltage setting unit may determine the degree of deterioration of the smoothing capacitor 60 according to the total traveling distance and the total traveling time of the vehicle. Then, the voltage setting unit may correct the capacity of the smoothing capacitor 60 when mounted on the vehicle according to the degree of deterioration, and calculate the allowable deviation A2 based on the corrected capacity of the smoothing capacitor 60. Further, the voltage setting unit may calculate the allowable deviation based on the corrected capacity of the smoothing capacitor 60 and any one of the maps.

The discharge unit turns off the SMRs 71 and 72 after it is determined that the detection voltage VHd of the voltage VH has reached the target voltage in precharge, that is, after it is determined that the precharge of the smoothing capacitor 60 is completed. The electric power stored in the filter capacitor 40 is discharged as it is. This makes it possible to suppress the current flowing from the filter capacitor 40 to the SMR 71 when the SMRs 71 and 72 are switched from off to on. Therefore, the positive side allowable deviation A1 can be further increased as compared with the case where the electric power stored in the filter capacitor 40 is not discharged.

Specifically, the discharging section operates the DC/DC converter 30 to discharge the electric charge of the filter capacitor 40. Alternatively, the discharging unit may operate the booster circuit 50 to discharge the electric charge of the filter capacitor 40. As a result, the voltage VL of the filter capacitor 40 can be adjusted without changing the voltage VH of the smoothing capacitor 60. Note that the voltage VL changes from a value substantially equal to the voltage VL as the voltage VL is adjusted.

After it is determined that the pre-charging of the smoothing capacitor 60 is completed, the energizing unit switches the SMRs 71 and 72 from off to off to enter the normal mode in which the main battery 10 and the booster circuit 50 are energized. Specifically, the energizing unit turns the SMRs 71 and 72 from off to on after it is determined that the detection voltage VHd of the voltage VL has reached the target voltage set by the voltage setting unit.

Then, when the position of the start switch is switched from the on position to the off position, the ECU 90 first turns off the SMR 71, and then turns off the SMR 72 so that the main battery 10, the first inverter 200, and the second inverter 400 are electrically connected. The active connection. At this time, the voltages of the first inverter 200 and the second inverter 400 gradually converge to a weak voltage near 0V.

Next, a processing procedure for performing the precharge will be described with reference to the flowchart of FIG. This processing procedure is performed by the ECU 90 when the start switch is switched from the off position to the start position.

First, in step S10, it is determined whether or not there is a precharge request. The case where there is no precharge request even if the start switch is switched to the start position is when there is some abnormality in the power supply system 80 and its surroundings. If the determination in step S10 is no, in step S11, the process waits without precharging.

On the other hand, if the determination in step S10 is YES, the detected voltage VBd of the voltage VB is acquired from the voltage sensor 81 in step S12. Then, in step S13, the range of allowable deviations -A2 to A1 is calculated from the voltage corresponding allowable map. Subsequently, in step S14, a range of the detection error of the voltage VB −ΔVB2 to ΔVB1 and a range of the detection error of the voltage VH −ΔVH2 to ΔVH1 are calculated from the voltage corresponding error map.

Then, in step S15, the target voltage in precharge is calculated from the detection voltage VBd of the voltage VB, the allowable deviation A2, the detection error ΔVB1, and the detection error ΔVH2.

Subsequently, in step S16, the target voltage in the precharge is set as the command voltage of the DC/DC converter 30, and the DC/DC converter 30 is operated to precharge the smoothing capacitor 60.

Succeedingly, in a step S17, it is determined whether or not the detection voltage VHd of the voltage VH has reached the target voltage in the precharge. When the determination in step S17 is NO, that is, when the detected voltage VHd of the voltage VH has not reached the target voltage, the process of step S17 is repeatedly executed.

On the other hand, if the determination in step S17 is YES, that is, if the detected voltage VHd of the voltage VH reaches the target voltage, in step S18, the SMRs 71 and 72 are switched from off to on, and the precharge mode is switched to the normal mode. .. At this time, before turning on the SMRs 71 and 72, it is preferable to discharge the charges until the voltage VL of the filter capacitor 40 reaches a target voltage that does not take the predetermined voltage ΔVS into consideration. This is the end of the process.

According to this embodiment described above, the following effects are exhibited.

The target voltage is set to a value higher than the detected value of the voltage VB by the predetermined voltage ΔVS. As a result, the deviation ΔV between the true value VBt of the voltage VB and the true value VHt of the voltage VH is set to the allowable deviation range −A2, regardless of whether the detection error of the voltage VH occurs on the higher side or the lower side. ~ A1 can be easily entered. The diode 54 is generally provided in the booster circuit. Therefore, damage to the SMR 71 can be suppressed by simple control while using a general circuit of the power supply system 80.

The predetermined voltage ΔVS is set such that the lower limit of the true value VHt of the voltage VH can be higher than the lower limit of the allowable range of the voltage VH. As a result, the deviation ΔV can be surely kept within the allowable deviation range −A2 to A1.

The voltage sensors 81 and 82 have a relatively small detection error in the assumed detection voltage range, but have a relatively large detection error outside the assumed detection voltage range. Therefore, the detection error ranges −ΔVB2 to ΔVB1 and −ΔVH2 to ΔVH1 of the voltage VB and the voltage VH can be calculated based on the voltage correspondence error map.

Even if the current flowing through the SMR 71 changes according to the voltage VB or the voltage VH when the SMRs 71 and 72 are switched from OFF to ON, the allowable deviation range −A2 to A1 is appropriately calculated based on the voltage corresponding allowable map. can do.

When the main battery 10 is used in the proper temperature range, the allowable deviation A2 becomes relatively large, but when the main battery 10 is used in a temperature outside the proper temperature range. The allowable deviation A2 is relatively small. Therefore, the allowable deviation range −A2 to A1 can be calculated based on the temperature corresponding allowable map.

When the main battery 10 is used in the proper temperature range, the magnitude of the detection error is relatively small, but when the main battery 10 is used in a temperature outside the proper temperature range, The magnitude of the detection error becomes relatively large. Therefore, the error range −ΔVB2 to ΔVB1, −ΔVH2 to ΔVH1 can be calculated based on the temperature correspondence error map.

The magnitude of the allowable deviation A2 changes according to the capacity of the smoothing capacitor 60. Therefore, the allowable deviation range −A2 to A1 can be calculated based on the capacity of the smoothing capacitor 60.

When the SMRs 71 and 72 are turned on, the discharge from the smoothing capacitor 60 to the SMR 71 is suppressed by the diode 54, but the discharge from the filter capacitor 40 to the SMR 71 is not suppressed. However, since the capacity of the filter capacitor 40 is generally smaller than the capacity of the smoothing capacitor 60, it is possible to increase the allowable deviation A1 on the positive side by only suppressing the discharge from the smoothing capacitor 60, as compared with the case where it is not suppressed. it can. Here, after the precharge is completed, the electric power stored in the filter capacitor 40 is discharged, so that the discharge from the filter capacitor 40 to the SMR 71 is suppressed when the SMRs 71 and 72 are turned on. Therefore, the allowable deviation A1 on the positive side can be further increased.

-By operating the DC/DC converter 30, only the voltage VL of the filter capacitor 40 can be adjusted without adding a new circuit.

By operating the booster circuit 50, only the voltage VL of the filter capacitor 40 can be adjusted without adding a new circuit.

(Other embodiments)
In the above embodiment, as a “voltage source” that is connected to the connection between the SRM 71, 72 and the booster circuit 50 and outputs a voltage higher than that of the main battery 10 before switching the SMR 71, 72 from the disconnected state to the connected state, Although the DC/DC converter 30 that boosts the voltage of the machine battery 20 is used, this may be changed.

Specifically, a power converter that boosts electric power supplied from a power source other than the auxiliary battery 20 to a voltage higher than that of the main battery 10 may be used as the “voltage source”.

For example, as shown in FIG. 4, a DC/DC converter 30a that boosts the output voltage of the main battery 10 may be used as the “voltage source”. The input terminals of the DC/DC converter 30a are connected to both terminals of the main battery 10 on the main battery 10 side of the SMRs 71 and 72. The output terminal of the DC/DC converter 30a is connected to the filter capacitor 40 (the input terminal of the booster circuit 50) on the booster circuit 50 side of the SMRs 71 and 72.

Further, as shown in FIG. 5, the DC/DC converter 30b that boosts the electric power supplied from the capacitor 21 to a voltage higher than that of the main battery 10 may be used as the “voltage source”. The input terminal of the DC/DC converter 30b is connected to both terminals of the capacitor 21. The output terminal of the DC/DC converter 30b is connected to the filter capacitor 40 (the input terminal of the booster circuit 50) on the booster circuit 50 side of the SMRs 71 and 72. The DC/DC converter 30b is a bidirectional DC/DC converter, and charges the capacitor 21 using the electric power stored in the main battery 10, the filter capacitor 40, and the smoothing capacitor 60. The capacitor 21 may be a general capacitor or an electric double layer capacitor.

Further, as shown in FIG. 6, the auxiliary battery 20 may be omitted from the power supply system, and the “power supply system control device” may be applied to a configuration including a step-down converter 20c that steps down the output voltage of the main battery 10. .. The step-down converter 20c is connected to the load 100 mounted on the vehicle and supplies electric power to the load 100. In this configuration, the DC/DC converter 30c that boosts the electric power supplied from the step-down converter 20c as a power source to a voltage higher than that of the main battery 10 is used as a “voltage source”.

Alternatively, a solar cell (solar panel) provided on the roof of an automobile or the like may be used as a power source, and a DC/DC converter that boosts electric power supplied from the solar cell to a voltage higher than that of the main battery 10 may be used as a “voltage source”. Good.

Further, instead of the DC/DC converter, an AC/DC converter that converts AC power supplied from an AC power supply and outputs a DC voltage higher than that of the main battery 10 may be used as the “voltage source”.

Specifically, as shown in FIG. 7, an AC/DC converter 30d that is mounted on a vehicle and that converts AC power output from a commercial AC power supply 110 into DC power and charges the main battery 10 is used. It may be used as a “voltage source”.

In addition, an AC/DC converter that is provided outside the vehicle, converts AC power output from a commercial AC power supply into DC power, and charges the main battery 10 by being connected to the power supply system of the vehicle. It may be used as a "voltage source".

In addition, an AC/DC converter that is mounted on a vehicle and that converts AC power output from an on-vehicle generator (alternator or motor generator) into DC power and charges the main battery 10 is used as a “voltage source”. Good. The vehicle-mounted generator may be powered by a motor, an engine, or the like that drives the vehicle-mounted generator to generate power.

A battery that outputs a voltage higher than that of the main battery 10 may be used as the “voltage source”. The battery used as the "voltage source" may be a secondary battery such as a lithium ion storage battery or a primary battery such as a fuel cell.

Further, a configuration may be used in which a plurality of “voltage sources” described above are used in combination. That is, for example, both the DC/DC converter 30 and the DC/DC converter 30a may be provided.

In the above embodiment, the diode 54 included in the booster circuit 50 (more specifically, the diode 54 provided on the higher potential side among the diodes 54 and 55 used by the booster circuit 50 for boosting operation) is smoothed from the SMR 71 side. Although it is used as a “regulating element” that does not regulate the current flow to the capacitor 60 side and regulates the current flow from the smoothing capacitor 60 side to the SMR 71 side, this may be changed. For example, a diode whose anode is connected to the SMR 71 side and whose cathode is connected to the coil 51 side may be newly provided between the SRM 71 and the booster circuit 50 (coil 51).

A switch (more specifically, a MOS switch) may be used instead of the diode. In the configuration using the switch, for example, a switch is provided between the SRM 71 and the booster circuit 50 (coil 51), and then the switch is turned on when the voltage on the SRM 71 side is higher than the voltage on the booster circuit 50 side. When the voltage on the side is lower than the voltage on the booster circuit 50 side, control may be performed to turn off the switch. More specifically, the ECU 90 may acquire the detected value of the current flowing through the switch and perform on/off control of the switch based on the direction of the current flowing through the switch.

In the above-described embodiment, it is determined whether the detection voltage VHd of the voltage VH has reached the target voltage in precharge, and when the detection voltage VHd of the voltage VH has reached the target voltage, the SMRs 71 and 72 are turned on. And the precharge mode is switched to the normal mode (steps S17 and S18 in FIG. 3). Here, the determination as to whether or not the detected voltage VHd of the voltage VH has reached the target voltage in precharge may be omitted.

The DC/DC converter 30 outputs a voltage higher than that of the main battery 10 before switching the SMRs 71 and 72 from the disconnected state to the connected state. Therefore, for example, by supplying power from the DC/DC converter 30 to the smoothing capacitor 60 for a predetermined time, the voltage across the terminals of the smoothing capacitor 60 can be made higher than that of the main battery 10. When the voltage across the terminals of the smoothing capacitor 60 is higher than that of the main battery 10, a large current flows from the smoothing capacitor 60 to the main battery 10 when the SMRs 71 and 72 are switched from the disconnected state to the connected state. It can be suppressed by the diode 54 which is a “regulating member”.

-Instead of the switching elements 52, 53 and the diodes 54, 55, two body diode built-in type switching elements, for example, two MOSFETs may be connected in series. In this case, the upper arm MOSFET is turned off when the MSRs 71 and 72 are switched from off to on after the precharge is completed. By controlling the upper arm MOSFET in this manner, the upper arm MOSFET serves as a limiting element instead of the diode 54.

The charge of the filter capacitor 40 does not have to be discharged after the precharge is completed and before the SMRs 71 and 72 are switched from off to on. Even if the charge of the filter capacitor 40 is not discharged, the deviation ΔV falls within the allowable deviation range −A2 to A1 by setting the target voltage in the precharge to a value higher than the detected value of the voltage VB by the predetermined voltage ΔVS. Can be made easier.

10... Main battery, 20... Auxiliary battery, 30... DC/DC converter, 50... Booster circuit, 54... Diode, 60... Smoothing capacitor, 80... Power supply system, 90... ECU.

Claims (14)

A main power storage device (10), a smoothing capacitor (60), a booster circuit (50) including the smoothing capacitor for boosting a voltage on the main power storage device side and outputting the boosted voltage to the smoothing capacitor side, A controller (90) for a power supply system, which is applied to a power supply system (80) comprising: an open/close switch (71, 72) for electrically connecting or disconnecting the booster circuit,
The power system is
A voltage source that is connected to the connection portion between the open/close switch and the booster circuit, and outputs a voltage higher than that of the main power storage device before the open/close switch is switched from a disconnection state to a connection state;
A restriction element that does not restrict the flow of current from the open/close switch side to the smoothing capacitor side and that restricts the flow of current from the smoothing capacitor side to the open/close switch side,
Have
A precharge unit for supplying electric power from the voltage source to the smoothing capacitor to precharge the smoothing capacitor before switching the open/close switch from the disconnection state to the connection state;
A target voltage in the precharge of the smoothing capacitor, a voltage setting unit that is equal to or lower than the output voltage of the voltage source, and that is set to a value higher by a predetermined voltage than the detection voltage of the main power storage device,
After it is determined that the detected voltage of the smoothing capacitor has reached the target voltage, an energizing unit that puts the open/close switch in a connected state,
The voltage setting unit, the lower limit value of the value considering the detection error of the predetermined voltage, the detection voltage of the main power storage device and the smoothing capacitor with respect to the voltage of the main power storage device, the voltage of the main power storage device. On the other hand, a control device of the power supply system that sets the predetermined voltage so as to be higher than a lower limit value of a permissible range of the voltage of the smoothing capacitor taking into account a permissible deviation and lower than a voltage of the main power storage device. A detection error of the detection voltage of the main power storage device according to the voltage of the main power storage device or the voltage of the smoothing capacitor, and a voltage correspondence error map showing a detection error of the detection voltage of the smoothing capacitor,
The control device of the power supply system according to claim 1 , wherein the voltage setting unit calculates a detection error of a detection voltage of the main power storage device and the detection voltage of the smoothing capacitor based on the voltage correspondence error map. A voltage corresponding allowable map showing the allowable deviation according to the voltage of the main power storage device or the voltage of the smoothing capacitor,
Wherein the voltage setting unit, based on the voltage corresponding permissible map, the controller of the power supply system according to claim 1 or 2 calculates the allowable deviation. A temperature corresponding allowable map showing the allowable deviation according to the temperature in the operating environment of the power supply system,
Wherein the voltage setting unit, based on the temperature corresponding permissible map, the controller of the power supply system according to claim 1 for calculating the allowable deviation. A temperature corresponding error map showing a detection error of the detection voltage of the main power storage device and the smoothing capacitor according to the temperature in the usage environment of the power supply system,
Wherein the voltage setting unit, based on the temperature corresponding error map, the control unit of the power supply system according to any one of claims 1 to 4 for calculating the detection error. Wherein the voltage setting unit, the smoothing based on the capacitance of the capacitor, the control device of the power supply system according to claim 1 for calculating the allowable deviation. The power supply system includes a sub power storage device (20) having a lower voltage than the main power storage device,
The voltage source, which is connected between the connecting portion and the sub power storage device, any one of the claims 1 to 6 which is the sub power storage device DC / DC converter output voltage by converting an output of (30) The control device for the power supply system according to item 1. The power supply system includes a filter capacitor (40) connected in parallel between the DC/DC converter and the booster circuit,
A target voltage in the precharge of the smoothing capacitor, a voltage setting unit that is equal to or lower than the output voltage of the voltage source, and that is set to a value higher by a predetermined voltage than the detection voltage of the main power storage device,
After it is determined that the detection voltage of the smoothing capacitor has reached the target voltage, a discharging unit that discharges the power stored in the filter capacitor,
It is determined that the detected voltage of the smoothing capacitor has reached the target voltage, the discharging unit discharges the electric power stored in the filter capacitor, and then an energizing unit that brings the open/close switch into a connected state,
The control device for the power supply system according to claim 7 , further comprising: A main power storage device (10), a smoothing capacitor (60), a booster circuit (50) including the smoothing capacitor for boosting a voltage on the main power storage device side and outputting the boosted voltage to the smoothing capacitor side, A controller (90) for a power supply system, which is applied to a power supply system (80) comprising: an open/close switch (71, 72) for electrically connecting or disconnecting the booster circuit,
The power system is
A voltage source that is connected to the connection portion between the open/close switch and the booster circuit, and outputs a voltage higher than that of the main power storage device before the open/close switch is switched from a disconnection state to a connection state;
A restriction element that does not restrict the flow of current from the open/close switch side to the smoothing capacitor side and that restricts the flow of current from the smoothing capacitor side to the open/close switch side,
A sub power storage device (20) having a lower voltage than the main power storage device,
Have
The voltage source is a DC/DC converter (30) that is connected between the connection unit and the sub power storage device and that converts and outputs an output voltage of the sub power storage device,
The power supply system includes a filter capacitor (40) connected in parallel between the DC/DC converter and the booster circuit,
A precharge unit for supplying electric power from the voltage source to the smoothing capacitor to precharge the smoothing capacitor before switching the open/close switch from the disconnection state to the connection state ;
A target voltage in the precharge of the smoothing capacitor, a voltage setting unit that is equal to or lower than the output voltage of the voltage source, and that is set to a value higher by a predetermined voltage than the detection voltage of the main power storage device,
After it is determined that the detection voltage of the smoothing capacitor has reached the target voltage, a discharging unit that discharges the power stored in the filter capacitor,
A power supply unit that determines that the detected voltage of the smoothing capacitor has reached the target voltage, discharges the power stored in the filter capacitor, and then switches the open/close switch to a connected state. The control unit of the system. A target voltage in the precharge of the smoothing capacitor, a voltage setting unit that is equal to or lower than the output voltage of the voltage source, and that is set to a value higher by a predetermined voltage than the detection voltage of the main power storage device,
The control device of the power supply system according to claim 9, further comprising: an energization unit that sets the open/close switch to a connection state after it is determined that the detection voltage of the smoothing capacitor has reached the target voltage. The control device of the power supply system according to claim 8, wherein the discharging unit operates the DC/DC converter to discharge the electric power stored in the filter capacitor. The control device of the power supply system according to claim 8, wherein the discharging unit operates the booster circuit to discharge the electric power stored in the filter capacitor. As the regulating element, the control unit of the power supply system according to any one of claims 1 to 12, characterized in that a diode is used for the booster circuit has. 14. The power supply device as claimed in claim 1 , wherein the voltage source is supplied with power from a predetermined power source and outputs a voltage higher than that of the main power storage device before switching the open/close switch from a disconnection state to a connection state. 2. The control device for the power supply system according to item 1.

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