Discharge control device

Abstract

Even if the vehicle's maximum discharge voltage is unknown, the vehicle can initiate discharge. [Solution] This invention relates to a discharge control device that outputs discharge power from a power storage device mounted on a vehicle. There are multiple discharge voltages to be requested, and after notifying a discharge request with one of the selected discharge voltages (YES in 24), if discharge from the vehicle does not start within a predetermined time (NO in S26), the discharge voltage to be requested is changed from the notified discharge voltage and a discharge request is made (S27).

Description

Technical Field

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[0001] The present disclosure relates to a discharge control device that supplies discharge power from a power storage device mounted on a vehicle to an external device.

Background Art

[0002] Conventionally, vehicles such as hybrid vehicles and electric vehicles are equipped with secondary batteries and drive a motor with the power from the secondary batteries to run.

[0003] In the case of an electric vehicle, it is necessary to charge the secondary battery mounted on the vehicle with power from an external charging facility. Also, in a hybrid vehicle, there is a plug-in hybrid vehicle that can be charged with external power.

[0004] In addition, the secondary batteries of such vehicles are relatively large in capacity, and a V2H (vehicle to home) system that supplies the power of the vehicle's secondary battery to facilities such as a residence during a power outage is known.

[0005] In this V2H system, a charge / discharge device (EVPS: Electric Vehicle Power Station) is provided in a residence or the like, connected to the vehicle, and used to charge the vehicle's secondary battery from the residence side or supply power to the residence with the power of the vehicle's secondary battery.

[0006] In the V2H system, a system that outputs DC power from the vehicle side has been put into practical use, but there are also proposals for a system that outputs AC power. There are several standards for charging and discharging in the V2H system, and equipment-side cables and connectors according to the standards, and inlets for connecting connectors on the vehicle side are used. Also, in order to perform charging and discharging, it is necessary to determine various conditions such as voltage and current, communicate between the vehicle side and the charge / discharge device, and set various conditions for charging and discharging.

Prior Art Documents

[0008] As mentioned above, communication takes place between the EVPS and the vehicle to set charging and discharging conditions, but there are cases where sufficient conditions cannot be set. For example, since the EVPS does not know the upper limit of the vehicle's discharge voltage, it may request a discharge at a discharge voltage that the vehicle does not support, which may result in the vehicle not discharging. [Means for solving the problem]

[0009] The discharge control device according to this disclosure is a discharge control device that outputs discharge power from an energy storage device mounted on a vehicle, and has multiple discharge voltages to request, and after notifying a discharge request with one of the selected discharge voltages, if discharge from the vehicle does not start within a predetermined time, it changes the discharge voltage to be requested from the notified discharge voltage and makes a discharge request. [Effects of the Invention]

[0010] According to the discharge control device described herein, it is possible to initiate discharge from the vehicle even if the discharge voltage on the vehicle side is unknown. [Brief explanation of the drawing]

[0011] [Figure 1] This is a block diagram showing the configuration of V2H (AC version) related to this disclosure. [Figure 2] This diagram shows the inlet and connector configuration. [Figure 3] This diagram shows the control circuit for the CPTL signal and the Proximity signal. [Figure 4] This flowchart shows the vehicle's operation during a discharge. [Figure 5] This is a flowchart showing the operation of the equipment during a discharge. [Figure 6]This is a sequence diagram showing the operation of the vehicle and equipment during a discharge. [Figure 7] This flowchart shows another example of the vehicle's operation during a discharge. [Figure 8] This flowchart shows another example of the equipment's operation during a discharge. [Figure 9] This diagram shows the functional assignment of the vehicle-side detection voltage in the Proximity signal. [Modes for carrying out the invention]

[0012] The embodiments of this disclosure will be described below with reference to the drawings. The embodiments described below are not limiting to this disclosure, and configurations formed by selectively combining multiple examples are also included in this disclosure.

[0013] "System Configuration" Figure 1 is a block diagram showing the configuration of the V2H (AC version) related to this disclosure.

[0014] Equipment 100 is equipped with a distribution board 12, to which AC power is supplied from the power company's grid 10. This AC power is single-phase 200V, but may also be three-phase 200V or single-phase 100V. Equipment 100 is the user's residence, etc.

[0015] Various electrical appliances and other loads 14 are connected to the distribution board 12, and power from the grid 10 is supplied to the loads 14 via the distribution board 12. This corresponds to the use of electricity purchased from a power company in a household.

[0016] An EVPS 20 is connected to the distribution board 12. A solar cell 22 is also connected to the EVPS 20. The EVPS 20 includes a DC / DC converter, an AC / DC converter, and a DC / AC converter. The EVPS 20 converts the AC power (AC) from the distribution board 12, the AC power (AC) supplied from the vehicle side, and the DC power supplied from the solar cell into the DC power (DC) of the DC line inside the EVPS 20 and supplies it to the DC line. Also, the EVPS 20 can convert the DC power of the DC line into AC power and output it to both the vehicle side and the distribution board side. The AC power output from the EVPS 20 to the distribution board 12 can be supplied to the load 14 via the distribution board 12 and can also be supplied to the grid 10. The output of this AC power to the grid 10 corresponds to selling electricity (selling electricity to the power company). Also, the AC power output from the EVPS 20 to the vehicle side is used for charging the vehicle, and the AC power supplied from the vehicle can also be output to the distribution board 12.

[0017] A cable 30 is connected to the EVPS 20. This cable 30 is a cable called TYPE1 and can supply AC power to the EVPS 20 and output the AC power from the EVPS 20.

[0018] The cable 30 includes a cable body 32 and a connector 34 provided at the tip. The cable 30 has four conduction paths, two of which are power lines AC1 and AC2 for single-phase AC (100V or 200V), and the remaining two are CPLT signal lines and Proximity signal lines. A control circuit 24 is provided in the EVPS 20, and this control circuit 24 controls the states of the CPLT signal and the Proximity signal line and controls the operation of the EVPS 20 from these states. Note that Proximity Detection is called Proximity.

[0019] Vehicle 200 is, for example, an electric vehicle. Vehicle 200 is equipped with a power storage device 40 consisting of a secondary battery such as a lithium-ion battery. A motor 44 is connected to the power storage device 40 via a power converter 42 including an inverter. DC power from the power storage device 40 is converted into a predetermined AC current by the inverter of the power converter 42 and supplied to the motor 44, causing vehicle 200 to move. When vehicle 200 is regenerating, the power stored in the power storage device 40 can be charged by supplying regenerative power from the motor 44 to the power storage device 40 via the power converter 42.

[0020] Furthermore, the power converter 42 is equipped with an OBC (onboard charger) 46, to which an inlet 48 is connected. The connector 34 of the cable 30 described above is connected to this inlet 48. By connecting the inlet 48 and the connector 34, the power lines AC1 and AC2 on the equipment side and the vehicle side, as well as the CPLT signal line and the Proximity signal line are connected. Power lines AC1 and AC2 are connected to the OBC 46.

[0021] The OBC 46 converts the AC power supplied from the equipment side via the inlet 48 into DC power, and supplies the resulting DC power to the energy storage device 40 to charge the energy storage device 40. The OBC 46 can also receive DC power from the energy storage device 40, convert it into AC power, and supply the resulting AC power to the equipment side via the inlet 48. In this embodiment, the inlet 48 functions as an AC discharge port.

[0022] The CPLT signal line and Proximity signal line of inlet 48 are connected to the control circuit 50. The control circuit 50 controls the state of the CPLT signal and Proximity signal line, and controls the operation of the power converter 42 based on these states.

[0023] "About connectors" Figure 2 shows the configuration of the vehicle-side inlet 48 and the equipment-side connector 34. The inlet 48 includes five sockets into which the five pins of the connector 34 are inserted and connected. L1 and L2 are for connecting AC power (AC1 and AC2), CS is for connecting the Proximity signal, CP is for connecting the CPLT signal, and PE is for connecting the ground (GND). The connector 34 also has a latch 36 on the side that is inserted into the inlet 48, which is inserted into the latch receiver 52 of the inlet 48 and mechanically latched. The connector 34 also has a latch release button 38, and pressing down this latch release button 38 releases the latch of the latch 36 from the latch receiver 52.

[0024] "Regarding signal lines" As described above, in this system, CPLT signals and proximity signals are exchanged between the vehicle 200 and the equipment 100.

[0025] The CPTL signal is a control signal that can instruct the equipment side on the conditions for discharge from the vehicle side. The control circuit 24 can instruct the discharge voltage from the vehicle side by controlling the frequency of the CPTL signal, and can instruct the upper limit discharge current from the vehicle side by controlling the duty cycle. In addition, the vehicle side can signal the start of discharge, the mating status of the connector 34, etc., by controlling the voltage of the CPTL signal.

[0026] For example, regarding the frequency of the CPTL signal, a frequency of 125Hz means a discharge voltage of 100VAC, a frequency of 166Hz means a discharge voltage of 200VAC, and a frequency of 1kHz means charging. As for the duty cycle, a 10% or higher is usable, and the relationship between duty cycle [%] = current [A] / 0.6 means that a 10% duty cycle is 6A and a 50% duty cycle is 30A.

[0027] Furthermore, the control circuit 24 on the equipment side can control the Proximity signal to inform the vehicle of the mating status (whether the cable is connected) and charging / discharging operations.

[0028] When the equipment side charges the vehicle 200's energy storage device 40, the energy storage device 40 is charged by the output from the EVPS 20.

[0029] When discharging power from vehicle 200 to equipment 100, there are two types of discharge initiation sequences: (1)CPLT method

[0030] The EVPS20 on the equipment side issues a discharge instruction to the vehicle side using a CPLT signal. (2) PROXIMITY method

[0031] The vehicle starts discharging electricity upon detecting a change in the Proximity signal.

[0032] "Regarding CPTL signals and Proximity signals" Figure 3 shows the control circuit for the CPTL signal and Proximity signal. First, the CPTL signal is generated in the EVPS20 as a signal with a predetermined frequency, duty cycle, and voltage, and supplied to the vehicle. Diode D1 is placed on the CPTL signal line on the vehicle side, and current flows only to the vehicle side. The cathode side of diode D1 is connected to ground via resistor R1, and is also connected to ground via switch SW1 and resistor R2. Therefore, the voltage of the CPTL signal can be lowered on the vehicle side by turning on switch SW1.

[0033] Furthermore, on the vehicle side, the Proximity signal line is set to a predetermined potential in the resistor divider between the power supply and ground (GND).

[0034] On the equipment side, one end of resistor R11 is connected to the Proximity signal line, and the other end of resistor R11 is connected to resistor R12 and one end of latch release switch 38a-1. The other end of resistor R12 and latch release switch 38a-1 are connected to ground via changeover switch SW11.

[0035] Furthermore, one end of resistor R13 is connected to the Proximity signal line on the equipment side, and the other end of resistor R13 is connected to resistor R14 and one end of latch release switch 38a-2. The other end of resistor R14 is connected to changeover switch SW11, and the other end of latch release switch 38a-2 is connected to changeover switch SW11 via resistor R15. In addition, discharge start switch SW12 is connected in parallel to resistor R15.

[0036] The selector switch SW11 selects resistor R12 and the other end of latch release switch 38a-1 when the vehicle is being charged, and selects the other ends of resistors R14 and R15 when the vehicle is being discharged.

[0037] Therefore, during charging, the latch release switch 38a-1 is turned on, causing the voltage of the Proximity signal to decrease.

[0038] Furthermore, during discharge, the latch release switch 38a-2 turns on, causing the proximity signal voltage to decrease, and the discharge start switch SW12 turns on, causing the proximity signal voltage to decrease even further.

[0039] "Discharge from the vehicle begins" As described above, the vehicle can recognize the discharge start request from the Proximity signal from the EVPS20. Furthermore, it can recognize the conditions for the discharge request and initiate discharge based on the CPTL signal from the EVPS20.

[0040] However, there are cases where the vehicle cannot satisfy the discharge conditions requested by the EVPS20 on the equipment side. For example, if the discharge voltage requested by the EVPS20 is higher than the discharge voltage that the vehicle can accept, discharge cannot be performed under those conditions. Therefore, even if the vehicle receives a discharge request from the equipment side, it cannot start discharging.

[0041] In this embodiment, by performing the following operations, the EVPS 20 grasps the discharge voltage of the vehicle before starting the discharge. Therefore, the EVPS 20 does not attempt to discharge at a voltage higher than the discharge voltage possible on the vehicle side, and discharge from the vehicle becomes possible.

[0042] <Operation on the vehicle side> FIG. 4 is a flowchart showing the operation during discharge from the vehicle side.

[0043] First, it is determined whether the connector 34 has been inserted into the inlet 48 (S11). If the determination in this step is NO, discharge is not required, and the determination in S11 is repeated. If the determination in S11 is YES, reception of the CPLT signal is started (S12).

[0044] Next, the frequency of the CPLT signal is determined to check if it corresponds to the discharge voltage (S13). As will be described later, the information on the discharge voltage sent from the EVPS side changes sequentially. Therefore, in the determination of S13, wait until it becomes Yes.

[0045] Then, if it is Yes in S13, the switch SW1 is closed and the voltage of the CPLT signal is lowered (S14). This starts the discharge on the vehicle side.

[0046] In this way, discharge is not started when the discharge voltage transmitted from the EVPS side exceeds the discharge voltage at which the vehicle can discharge.

[0047] <Operation on the EVPS side> FIG. 4 is a flowchart showing the operation during discharge from the EVPS side. First, it is determined whether the voltage of the CPLT signal has changed from 12V to 9V (S21). When the connector 34 is inserted into the inlet 48 and each signal line is connected, the determination in S21 becomes Yes. That is, when the signal line of the CPLT signal is connected to the signal line on the vehicle side, its voltage switches from 12V to 9V.

[0048] If the result in S21 is NO, the check is repeated. If the result is Yes, the frequency of the CPTL signal is set to the frequency corresponding to the discharge voltage requested (S22). It is recommended that the initial discharge request be set to the maximum discharge voltage.

[0049] Next, the timeout timer is reset and counting begins (S23). Then, it is determined whether the voltage of the CPLT signal has changed from 9V to 6V (S24). This is because when the vehicle starts discharging, switch SW1 is turned on, and the CPLT signal changes from 9V to 6V. If the determination in S24 is Yes, the discharge from the vehicle is accepted and control is made regarding the use of the discharged power (S25).

[0050] On the other hand, if the result of S24 is NO, it is determined whether the timeout timer, which started counting in S23, has timed out (S26). If the result of S26 is NO, the process returns to the S24 decision. If the result of S24 does not become Yes by the timeout, the result of S25 becomes Yes, and the discharge voltage of the CPLT signal is changed. That is, the frequency is changed to one corresponding to a different discharge voltage, in this example a lower discharge voltage, instead of the current duty cycle (S27). Then, the timeout timer is reset and counting starts again (S28), and the process returns to the S24 decision.

[0051] In this way, each time a timeout occurs, the frequency of the CPTL signal is changed to determine whether discharge will start (i.e., whether it became Yes in S24).

[0052] Then, if the result of the S24 check is Yes, the process moves to S25, where the EVPS20 controls the use of discharge power from the vehicle.

[0053] Figure 6 is a sequence diagram corresponding to the flowcharts in Figures 4 and 5. As shown, first, the user inserts the connector 34 of the equipment-side cable 30 into the vehicle-side inlet 48. This connects the signal line and changes the CPTL voltage from 12V to 9V. The EVPS starts oscillating the CPTL signal. The frequency is initially set to 166Hz, which corresponds to the larger discharge voltage of 200V that the vehicle can output.

[0054] In this example, if there is no response from the vehicle at a frequency of 166Hz (corresponding to a discharge voltage of 200V), and the frequency is switched to 125Hz (corresponding to a discharge voltage of 100V), switch SW1 is turned on (closed), the CPLT voltage is changed from 9V to 6V, and discharge begins. The CPLT signal then continues to oscillate at the frequency, duty cycle, and voltage of 6V during discharge. This ensures that discharge from the vehicle continues.

[0055] Furthermore, the duty cycle of the CPTL signal indicates the discharge limit current, and similarly to this embodiment, the discharge limit voltage can be sequentially changed, and an appropriate discharge limit voltage can be set by initiating discharge.

[0056] In this embodiment, first, the EVPS notifies the vehicle of an acceptable discharge voltage and performs a discharge start process. If the vehicle cannot handle the discharge voltage, it does not start discharging. If the EVPS does not start discharging after a certain timeout period has elapsed, it changes the discharge voltage and notifies the vehicle. Then, it performs a discharge start process and waits for the discharge to start. Thereafter, the discharge voltage is changed sequentially and this process is repeated until the discharge starts.

[0057] This will ultimately initiate discharge at a discharge voltage that the vehicle can accept.

[0058] Figures 7 and 8 are flowcharts showing modified examples of Figures 4 and 5.

[0059] Steps S11-S14 in Figure 7 are identical to those in Figure 4. In the example in Figure 7, if the result in S13 is NO, it is determined in S15 whether there is a stop request from the EVPS. If the result in S15 is NO, the process returns to S13. This is the same as the case where the result in S13 is NO in Figure 4. On the other hand, if the result in S15 is Yes, the process moves to receiving the CPLT signal in S12. That is, the process is restarted from the beginning, assuming that the connector is inserted.

[0060] Steps S21-S26 in Figure 8 are essentially the same as those in Figure 5. In the example in Figure 8, step S22 stores the frequency used when the previous discharge request was made and sets the frequency to one level lower than that frequency. The initial value can be set to a frequency corresponding to the maximum discharge voltage of the EVPS, and then to a frequency one level lower in discharge voltage.

[0061] Then, if the answer in S26 is Yes, a stop request is made, the processing of the discharge start request is temporarily stopped, and the process returns to S21 to restart the processing of the discharge start request.

[0062] The processes shown in Figures 7 and 8 perform the same operations as in Figures 4 and 5. If discharge does not start from the vehicle, the discharge voltage is gradually lowered to request discharge, and discharge begins when the vehicle becomes capable of discharging.

[0063] Note that the system can also be operated using the vehicle-side flowchart in Figure 8 and the EVPS-side flowchart in Figure 5.

[0064] "Effects of the Embodiment" According to the discharge control device of this embodiment, after notifying a discharge request with a selected discharge voltage, if discharge is not initiated from the vehicle within a predetermined time, the discharge voltage to be requested is changed from the notified discharge voltage and the discharge request is made again. Therefore, even if the vehicle's upper limit discharge voltage is unknown, discharge can be initiated from the vehicle.

[0065] By requesting discharge from a higher voltage among several available discharge voltages, and then, if the discharge request does not start, changing the requested discharge voltage to a lower voltage than the notified discharge voltage and making the discharge request again, the process leading up to the start of discharge can be made more efficient.

[0066] By remembering the discharge voltage at which the vehicle initiated discharge in response to a discharge request, and then requesting discharge at that same voltage the next time a discharge request is made, the processing efficiency can be improved.

[0067] When starting to use the discharge control device, it can be connected to the vehicle on a trial basis, and the discharge voltage at which the vehicle started discharging at that time can be stored in memory. By requesting a discharge at that same discharge voltage the next time a discharge is requested, the processing efficiency can be improved.

[0068] The system can store the discharge voltage at which each vehicle initiated discharge, and then, when a discharge request is made again, it can respond to multiple vehicles requesting discharge using the stored discharge voltage of that vehicle.

[0069] The user can set the discharge voltage for the discharge request that is notified to the vehicle. By requesting a discharge from the set discharge voltage, the user can request the correct discharge upper limit voltage if they know it.

[0070] By having a reset mechanism to reset the stored discharge voltage, it is possible to handle cases where the stored discharge upper limit voltage is changed.

[0071] Up to this point, we have described examples of discharge instructions using the CPLT method, but the same can be done for discharge using the PROXIMITY method. Figure 9 shows the functional assignment of the vehicle-side detection voltage in the Proximity signal (Proximity detection). When the assignment of the Proximity signal voltage is set as shown in Figure 9, the vehicle can be instructed to discharge using the following procedure. (i) First, by setting the resistor so that the voltage is between 2.36 and 1.8V, a discharge at 200V is required. (ii) If discharge from the vehicle does not start within a specified time, a 100V discharge is requested by setting the resistor to 3.2 to 4.0V. [Explanation of symbols]

[0072] 10 circuits, 12 distribution boards, 14 loads, 22 solar panels, 24 control circuits, 30 cables, 32 cable bodies, 34 connectors, 36 latches, 38 latch release buttons, 38a-1, 38a-2 latch release switches, 40 energy storage devices, 42 power converters, 44 motors, 48 ​​inlets, 50 control circuits, 52 latch receivers

Claims

1. A discharge control device that outputs discharge power from a power storage device mounted on a vehicle, If there are multiple discharge voltages to request, and after notifying the vehicle of a discharge request using one of these voltages, the system will change the requested discharge voltage from the notified voltage and resubmit the discharge request. Discharge control device.

2. A discharge control device according to claim 1, Among multiple discharge voltages, the system initiates a discharge request starting with the highest voltage. If the discharge request does not start, it changes the discharge voltage to be requested to a lower voltage than the previously notified discharge voltage and initiates the discharge request again. Discharge control device.

3. A discharge control device according to claim 1, In response to a discharge request, the system remembers the discharge voltage at which the vehicle initiated discharge, and then uses that same discharge voltage for the next discharge request. Discharge control device.

4. A discharge control device according to claim 1, When the discharge control device is first put into use, it is experimentally connected to the vehicle, and the discharge voltage at which the vehicle begins to discharge is stored in memory. The next time a discharge request is made, the discharge request will be made at that same discharge voltage. Discharge control device.

5. Discharge control device. A discharge control device according to claim 1, The system stores the discharge voltage at which each vehicle initiated discharge, and then, the next time a discharge request is made, it uses the stored discharge voltage of that vehicle.

6. A discharge control device according to claim 1, The user can set the discharge voltage for the discharge request that is notified to the vehicle, and the discharge request will be made from the set discharge voltage. Discharge control device.

7. A discharge control device according to any one of claims 2 to 4, It has a reset means for resetting the stored discharge voltage. Discharge control device.

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