JP2021112004A - Charge control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique for charging a battery from a charger even when there is an abnormality in a voltage sensor on the charger side of the charging relay. A charge control device includes a first relay that connects a battery that charges and discharges, a first node to which a load and a first voltage sensor are connected, a charger, and a second voltage sensor. It has a second node to be connected and a second relay to connect the first node. When the second voltage sensor is normal, the control unit turns on the first relay, and the voltage of the second node connected to the charger is about the same as the voltage of the first node, which is the voltage of the battery. After confirming with the second voltage sensor, the second relay is turned on to charge the battery with the charger, and if the second voltage sensor is abnormal, the second relay is turned on and charged. After confirming with the first voltage sensor that the voltage of the first node connected to the device is about the same as the output voltage of the battery, the first relay is turned on to charge the battery with the charger. [Selection diagram] Fig. 1

Description

The present invention relates to a charge control device that controls charging of a rechargeable battery.

Recently, electric vehicles that drive driving wheels with a motor generator have become widespread. Along with this, as a charger for charging a rechargeable battery mounted on an electric vehicle, a quick charger having a shorter charging time than a normal charger has become widespread. For example, a charge control device that controls charging of a battery has a system main relay that connects a motor generator to the battery and a charge relay that connects a quick charger to the battery via the system main relay.

Charging the battery from the quick charger is done by turning on the charging relay while the system main relay is on. Further, when the battery is connected to the motor generator to drive the motor generator, it is necessary to suppress the inrush current flowing through the smoothing capacitor connected between the positive electrode line and the negative electrode line used for charging / discharging. Therefore, when the battery is connected to the motor generator, the sub system main relay connected in series with a resistor between the negative electrode line of the battery and the negative electrode line of the motor generator is temporarily turned on. As a result, the inrush current is suppressed, and welding of the system main relay due to the inrush current is prevented (see Patent Document 1).

Japanese Unexamined Patent Publication No. 2015-89152

When the charging relay is turned on to charge the battery from the quick charger, the voltage on the quick charger side of the charging relay is precharged to the voltage on the system main relay side of the charging relay, so that the charging relay is welded by the inrush current. Is prevented. For example, the completion of precharging on the quick charger side is determined by the measured value of the voltage sensor provided on the quick charger side of the charging relay.

However, if the voltage sensor provided on the quick charger side of the charging relay fails, the precharge voltage cannot be measured, so that an inrush current may be generated and the charging relay may be welded. Therefore, when the voltage sensor fails, it is prohibited to turn on the charging relay in order to prevent the generation of inrush current. In this case, there is a problem that the battery cannot be charged by the quick charger.

Therefore, in view of the above problems, it is an object of the present invention to enable charging from the charger to the battery even when there is an abnormality in the voltage sensor on the charger side of the charging relay.

In order to achieve the above object, in one embodiment of the present disclosure,
Batteries that charge and discharge and
A first relay that connects the first node and the battery,
The load connected to the first node and
A first voltage sensor that measures the voltage of the first node,
A connector that is connected to the second node and to which the charger is connected,
A second relay connecting the first node and the second node,
A second voltage sensor that measures the voltage of the second node,
When the second voltage sensor is normal, the voltage of the second node connected to the charger via the connector is connected to the battery by turning on the first relay. After confirming that the difference is a predetermined value with respect to the voltage of the second voltage sensor, the second relay is turned on, the battery is charged by the charger, and the second is charged. When an abnormality of the voltage sensor is detected, the voltage of the first node connected to the charger via the connector by turning on the second relay has a predetermined difference from the output voltage of the battery. After confirming that the voltage has been increased by the first voltage sensor, the control unit that turns on the first relay and charges the battery by the charger.
A charge control device characterized by having the above is provided.

According to the present embodiment, when an abnormality of the second voltage sensor is detected, the second relay is turned on before the first relay is turned on, and the first node is precharged by the output voltage of the charger. do. As a result, it can be confirmed by the first voltage sensor that the precharge voltage by the charger has become about the same as the output voltage of the battery, and based on the confirmation, the first relay can be turned on. As a result, even if there is an abnormality in the second voltage sensor, the battery can be charged using the charger. In other words, by changing the charging sequence according to whether the second voltage sensor is normal or abnormal, it is possible to charge the battery from the charger even if the second voltage sensor has an abnormality. Can be done.

According to the above-described embodiment, it is possible to charge the battery from the charger even when there is an abnormality in the voltage sensor on the charger side of the charging relay.

It is a block diagram which shows an example of the charge control device in one Embodiment. It is a control flow which shows the charging method from the charger to the battery carried out by the charge control device of FIG. It is explanatory drawing which shows an example of the charging sequence which the ECU carries out in steps S20 and S22 of FIG. It is a timing diagram which shows an example of the charging sequence when there is an abnormality in a VDC sensor. It is a timing diagram which shows an example of the charge sequence when the VDC sensor is normal. It is a figure which shows an example of the ECU shown in FIG.

Hereinafter, modes for carrying out the invention will be described with reference to the drawings.

[Charge control device configuration]
FIG. 1 is a block diagram showing an example of a charge control device according to an embodiment. For example, the charge control device 100 shown in FIG. 1 is mounted on a vehicle such as an electric vehicle. The charge control device 100 includes a battery 110 for charging and discharging, a PCU (Power Control Unit) 120, an ECU (Electronic Control Unit) 130, an inlet 140, a system main relay SMR, a charging relay DCR, a smoothing capacitor C1, and a voltage sensor VB, VL. , With VDC. Although not particularly limited, the voltage sensor VB is included in the battery 110, and the voltage sensor VL is included in the PCU 120.

The battery 110 is, for example, an assembled battery including a plurality of cells connected in series. The voltage sensor VB measures the voltage between the positive electrode line PL1 and the negative electrode line NL1 of the battery 110, and outputs the measured value to the ECU 130. When the battery 110 is charged with a predetermined capacity, a predetermined DC voltage (for example, 360 V) is generated between the positive electrode line PL1 and the negative electrode line NL1.

The PCU 120 has, for example, an inverter (not shown) that converts DC power received from the battery 110 into AC power. Although not shown, the motor generator that drives the drive wheels operates by receiving AC power converted by the inverter. The motor generator can also generate electricity by regenerative braking. The electric power generated by the motor generator is converted into DC electric power by the inverter and stored in the battery 110. The voltage sensor VL measures the voltage between the positive electrode line PL2 and the negative electrode line NL2, and outputs the measured value to the ECU 130.

The system main relay SMR (SMR-B, SMR-G) is arranged between the battery 110 and the PCU 120, and on / off is controlled by a relay control signal output from the ECU 130. The system main relay SMR-B connects the positive electrode line PL1 of the battery 110 to the positive electrode line PL2 of the PCU 120. The system main relay SMR-G connects the negative electrode line NL1 of the battery 110 to the negative electrode line NL2 of the PCU 120. Although not shown, for example, a resistor connected in series and a sub system main relay (not shown) are connected in parallel with the system main relay SMR-B between the negative electrode lines NL1 and NL2.

The charging relay DCR (DCR-B, DCR-G) is arranged between the positive electrode line PL2 and the negative electrode line NL2 and the positive electrode line PL3 and the negative electrode line NL3 of the inlet 140, and is turned on / by a relay control signal output from the ECU 130. Off is controlled. The voltage sensor VDC measures the voltage between the positive electrode line PL3 and the negative electrode line NL3, and outputs the measured value to the ECU 130. The inlet 140 can be connected to the connector 210 of the charger 200. For example, the charger 200 is a quick charger that outputs a DC voltage, and is compatible with the CCS (Combined Charging System) standard.

The voltage sensor VL is an example of a first voltage sensor, and the voltage sensor VDC is an example of a second voltage sensor. The ECU 130 is an example of a control unit, and the inlet 140 is an example of a connector. The system main relay SMR (SMR-B, SMR-G) is an example of the first relay, and the charging relay DCR (DCR-B, DCR-G) is an example of the second relay. The positive electrode line PL2 and the negative electrode line NL3 are examples of the first node, and the positive electrode line PL3 and the negative electrode line NL3 are examples of the second node. The PCU 120 and the inverter and motor generator connected to the PCU 120 are examples of loads.

When the battery 110 is connected to the PCU 120 to drive a motor generator (not shown), for example, with the system main relay SMR-G turned off, the above-mentioned sub system main relay is turned on together with the system main relay SMR-B. Will be done. As a result, it is possible to prevent an inrush current from flowing through the smoothing capacitor C1, and it is possible to prevent the system main relay SMR-B from being welded by the inrush current.

The ECU 130 turns off the sub system main relay and turns on the system main relay SMR-G based on the voltage value measured by the voltage sensor VL becoming the voltage value measured by the voltage sensor VB. As a result, the charge control device 100 is put into an activated state in which the motor generator can be driven.

On the other hand, when the charger 200 is connected to the inlet 140 to charge the battery 110, the ECU 130 corresponds to the DC voltage output from the battery 110 with the system main relays SMR-B and SMR-G turned on. Instruct the charger 200 to precharge the voltage of. Then, the ECU 130 turns on the charging relays DCR-B and DCR-G based on the difference between the measured value of the voltage sensor VDC and the measured value of the voltage sensor VB within a predetermined value. As a result, it is possible to prevent an inrush current from flowing through the charging relays DCR-B and DCR-G, and to prevent welding of the charging relays DCR-B and DCR-G due to the inrush current.

When the voltage sensor VDC fails and the voltages of the positive electrode line PL3 and the negative electrode line NL3 cannot be measured, the ECU 130 determines that the difference between the measured value of the voltage sensor VDC and the measured value of the voltage sensor VB is within a predetermined value. I can't judge. Conventionally, by prohibiting charging from the charger 200 to the battery 110, it has been avoided that an inrush current flows through the charging relays DCR-B and DCR-G. In this case, the battery 110 could not be charged by the charger 200.

However, in this embodiment, the ECU 130 can charge the battery 110 from the charger 200 by using the measured value of the voltage sensor VL even when the voltage sensor VDC fails. Hereinafter, the voltage sensor VB is also referred to as a VB sensor, the voltage sensor VL is also referred to as a VL sensor, and the voltage sensor VDC is also referred to as a VDC sensor.

[Charging control flow]
FIG. 2 is a control flow showing a method of charging the battery 110 from the charger 200 implemented by the charge control device 100 of FIG. The control flow shown in FIG. 2 is realized, for example, by the CPU (Central Processing Unit) mounted on the ECU 130 of FIG. 1 executing a charge control program. The control flow of FIG. 1 shows a charge control method.

First, in step S10, the ECU 130 detects an abnormality in the VDC sensor while the battery 110 is being charged by the charger 200. Here, the ECU 130 detects an abnormality in the VDC sensor when the measured value of the VDC sensor exceeds the normal range, or when there is an abnormal fluctuation in the measured value of the VDC sensor. If the ECU 130 does not detect an abnormality in the VDC sensor during charging, steps S12, S14, S16, S18, S20, and S22 are not performed, and steps S24, S26, and S28 are performed.

Next, in step S12, the ECU 130 stores abnormality information indicating an abnormality of the VDC sensor in a memory or the like. Next, in step S14, the ECU 130 turns off the charging relays DCR-B and DCR-G, issues an instruction to the charger 200, and ends charging by the charger 200.

After that, in step S16, the ECU 130 detects, for example, an operation of a user or the like who charges the battery 110 with the charger 200. Then, the ECU 130 executes step S18. When the ECU 130 does not detect the operation of the user or the like for charging the battery 110 by the charger 200, the processing after step S18 is not performed.

In step S18, the ECU 130 refers to a memory or the like and determines whether or not there is a history of detecting an abnormality in the VDC sensor. The ECU 130 executes step S20 when there is an abnormality history, and executes step S22 when there is no abnormality history.

In step S20, the ECU 130 executes step S24 after executing the charging sequence at the time of abnormality of the VDC sensor. In step S22, the ECU 130 executes the normal charging sequence of the VDC sensor, and then performs step S24. An example of the charging sequence when the VDC sensor is abnormal in step S20 and the charging sequence when the VDC sensor is normal in step S22 will be described with reference to FIG.

In this embodiment, the charging sequence by the charger 200 is changed depending on whether an abnormality of the VDC sensor is detected or not. Therefore, even when the voltage cannot be measured due to a failure of the VDC sensor or the like, the charger 200 is used without generating an inrush current in the charging relays DCR-B and DCR-G as described with reference to FIG. The battery 110 can be charged.

In step S24, the ECU 130 charges the battery 110 with the charger 200. Next, in step S26, the ECU 130 determines whether or not a charging termination factor has occurred, executes step S28 if the termination factor occurs, and returns to step S24 if the termination factor does not occur. .. For example, the ECU 130 detects the occurrence of an termination factor when the battery 110 is fully charged, when a user or the like detects a charging stop operation, or when an abnormality is detected during charging.

In step S28, the ECU 130 stops the charging control of the battery 110 by the charger 200, and ends the charging control using the charger 200 shown in FIG.

[Processing content of charging sequence]
FIG. 3 is an explanatory diagram showing an example of a charging sequence executed by the ECU 130 in steps S20 and S22 of FIG.

When an abnormality occurs in the VDC sensor, the ECU 130 first turns on the charging relays DCR-B and DCR-G, and connects the charger 200 to the positive electrode line PL2 and the negative electrode line NL2. Next, the ECU 130 instructs the charger 200 of the precharge voltage, and causes the charger 200 to output the instructed precharge voltage. While the charger 200 is outputting the precharge voltage, the ECU 130 monitors the VL sensor to determine the completion of the precharge. Then, when the measured value of the VL sensor reaches the precharge voltage, the ECU 130 turns on the system main relays SMR-B and SMR-G. As a result, the charger 200 starts charging the battery 110.

When the VDC sensor is normal, the ECU 130 first turns on the system main relays SMR-B and SMR-G, and connects the battery 110 to the positive electrode line PL2 and the negative electrode line NL2. Next, the ECU 130 instructs the charger 200 of the precharge voltage, and causes the charger 200 to output the instructed precharge voltage. While the charger 200 is outputting the precharge voltage, the ECU 130 monitors the VDC sensor to determine the completion of the precharge. Then, when the measured value of the VDC sensor reaches the precharge voltage, the ECU 130 turns on the charge relays DCR-B and DCR-G. As a result, the charger 200 starts charging the battery 110.

[Charging sequence when there is an abnormality in the VDC sensor]
FIG. 4 is a timing diagram showing an example of a charging sequence when there is an abnormality in the VDC sensor. That is, FIG. 4 shows a timing diagram for carrying out the charging sequence on the left side of FIG. In FIG. 4, the VDC sensor is out of order, so that it cannot be measured. Although not particularly limited, it is assumed that the output voltage of the battery 110 is 360 V in the initial state of FIG. 4 (FIG. 4 (a)).

First, the ECU 130 sequentially turns on the charging relays DCR-B and DCR-G in the off state (FIG. 4B). As a result, the charger 200 is connected to one end of the system main relays SMR-B and SMR-G via the positive electrode line PL2 and the negative electrode line NL2, as shown on the right side of FIG. At this time, as shown in the timing diagram, the system main relays SMR-B and SMR-G are in the off state (FIG. 4 (c)). Further, the charger 200 stops the output of the DC voltage (FIG. 4 (d)).

After that, the ECU 130 instructs the charger 200 to output a precharge voltage corresponding to the output voltage of the battery 110. The charger 200 outputs a precharge voltage corresponding to the output voltage of the battery 110 (FIG. 4 (e)). Since the charging relays DCR-B and DCR-G are turned on, the precharge voltage output by the charger 200 is transmitted to the positive electrode line PL2 and the negative electrode line NL2, and the voltage value measured by the VL sensor rises (FIG. 4 (f)). When the difference between the voltage value measured by the VL sensor and the output voltage value (360V) of the battery 110 is within a predetermined value, the ECU 130 determines the completion of precharging and determines the completion of precharging, and the system main relays SMR-B and SMR-G. Are turned on in sequence (FIG. 4 (g)). As a result, the charging sequence is completed, and charging of the battery 110 by the charger 200 is started.

[Charging sequence when VDC sensor is normal]
FIG. 5 is a timing diagram showing an example of the charging sequence when the VDC sensor is normal. That is, FIG. 5 shows a timing diagram for carrying out the charging sequence on the right side of FIG. A detailed description of the same operation as in FIG. 4 will be omitted. Although not particularly limited, it is assumed that the output voltage of the battery 110 is 360 V in the initial state of FIG. 5 (FIG. 5 (a)).

First, the ECU 130 sequentially turns on the system main relays SMR-B and SMR-G in the off state (FIG. 5B). As a result, as shown on the right side of FIG. 5, the battery 110 is connected to one end of the charging relays DCR-B and DCR-G via the positive electrode line PL2 and the negative electrode line NL2. The description of the control for preventing welding of the system main relays SMR-B and SMR-G described above will be omitted. As shown in the timing diagram, the voltage value measured by the VL sensor rises due to the output of the voltage from the battery 110 (FIG. 5 (c)). At this time, the charging relays DCR-B and DCR-G are in the off state (FIG. 5D)). Further, the charger 200 has stopped the output of the DC voltage (FIG. 5 (e)).

After that, the ECU 130 instructs the charger 200 to output a precharge voltage corresponding to the output voltage of the battery 110. The charger 200 outputs the instructed precharge voltage (FIG. 5 (f)). Since the VDC sensor is operating normally, the voltages of the positive electrode line PL2 and the negative electrode line NL2 precharged by the charger 200 are measured (FIG. 5 (g)). When the difference between the voltage value measured by the VDC sensor and the output voltage value (360V) of the battery 110 is within a predetermined value, the ECU 130 determines the completion of precharging and sets the charging relays DCR-B and DCR-G. It is turned on sequentially (FIG. 5 (h)). As a result, the charging sequence is completed, and charging of the battery 110 by the charger 200 is started.
[Configuration example of ECU 130]
FIG. 6 is a diagram showing an example of the ECU 130 shown in FIG. The ECU 130 includes a CPU 11, a ROM (Read Only Memory) 12, a RAM (Random Access Memory) 13, an input interface unit 14, and an output interface unit 15. The CPU 11, ROM 12, RAM 13, input interface unit 14, and output interface unit 15 are connected to each other via a bus 16.

For example, the CPU 11 executes a charge control program that realizes the control flow shown in FIG. 2, and controls the operation of the vehicle on which the charge control device 100 of FIG. 1 is mounted. For example, the charge control program is stored in the ROM 12. The data handled by the CPU 11 and the abnormality information of the VDC sensor described with reference to FIG. 2 are stored in the RAM 13. The abnormality information of the VDC sensor may be stored in the built-in memory or register of the CPU 11.

The input interface unit 14 receives the measured values of the VB sensor, the VL sensor, and the VDC sensor, and outputs the received measured values to the CPU 11. The CPU 11 performs charging control of the battery 110 by the charger 200 and output control of the DC voltage from the battery 110 to the PCU 120 based on the measured values of the VB sensor, the VL sensor and the VDC sensor. Further, the input interface unit 14 receives information from various sensors mounted on the vehicle and outputs the received information to the CPU 11.

The output interface unit 15 outputs a relay control signal to the system main relays SMR-B and SMR-G and the charging relays DCR-B and DCR-G based on the instruction from the CPU 11, and performs on / off control. .. Further, the output interface unit 15 outputs a control signal to another control unit based on the instruction from the CPU 11.

As described above, in this embodiment, when an abnormality of the VDC sensor is detected, the charging relay DCR is turned on before the system main relay SMR is turned on, and the positive electrode line PL2 and the negative electrode line NL2 are precharged by the output voltage of the charger 200. do. As a result, it can be confirmed by the VL sensor that the precharge voltage by the charger 200 has become about the same as the output voltage of the battery 110, and based on the confirmation, the system main relay SMR can be turned on. As a result, the battery 110 can be charged using the charger 200 even when the VDC sensor is abnormal. In other words, by changing the charging sequence according to whether the VDC sensor is normal or abnormal, it is possible to charge the battery 110 from the charger 200 even when the VDC sensor is abnormal.

Although the embodiments for carrying out the present invention have been described in detail above, the present invention is not limited to such specific embodiments, and various modifications and improvements can be made without impairing the gist of the present invention. Is.

11 CPU
12 ROM
13 RAM
14 Input interface unit 15 Output interface unit 16 Bus 100 Charge control device 110 Battery 120 PCU
130 ECU
140 Inlet 200 Charger 210 Connector C1 Smoothing Capacitor DCR-B, DCR-G Charging Relay NL1, NL2, NL3 Negative Line PL1, PL2, PL3 Positive Line SMR-B, SMR-G System Main Relay VB, VDC, VL Voltage Sensor

Claims (1)

Batteries that charge and discharge and
A first relay that connects the first node and the battery,
The load connected to the first node and
A first voltage sensor that measures the voltage of the first node,
A connector that is connected to the second node and to which the charger is connected,
A second relay connecting the first node and the second node,
A second voltage sensor that measures the voltage of the second node,
When the second voltage sensor is normal, the voltage of the second node connected to the charger via the connector is connected to the battery by turning on the first relay. After confirming that the difference is a predetermined value with respect to the voltage of the second voltage sensor, the second relay is turned on, the battery is charged by the charger, and the second is charged. When an abnormality of the voltage sensor is detected, the voltage of the first node connected to the charger via the connector by turning on the second relay has a predetermined difference from the output voltage of the battery. After confirming that the voltage has been increased by the first voltage sensor, the control unit that turns on the first relay and charges the battery by the charger.
A charge control device characterized by having.

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