TW202239638A - Control method of power supply system - Google Patents

Abstract

The present invention relates to a control method of a power supply system, which is used in an electric vehicle. The electric vehicle includes a main battery, a motor controller, a voltage reduction device, a constant battery, and a vehicular load. The main battery is communicatively connected to a control unit. The constant battery is electrically connected to the step-down device through a charging power switch, and the vehicular load is electrically connected to the step-down device and the constant battery through a load power switch. Wherein, when the constant battery power is sufficient, the vehicle start process can give priority to starting the vehicular load, in order to achieve the shortest time to start the vehicle and the front or rear lights to give priority to the warning function of the oncoming vehicles. When the constant battery power is not sufficient, the vehicle start process gives priority to turn on the charging power switch, so that the battery can be charged first and the power output from the step-down device is provided for the vehicle load when the load power switch is turned on. As such, it is ensured that the constant battery power is sufficient to withstand the power consumption of the vehicular load, and it is avoided that the control unit cannot provide enough power to wake up the main battery due to excessive consumption, and the vehicle cannot be started normally.

Description

Control method of power system

The invention relates to a control method of a power supply system, especially a control method suitable for a power supply system of an electric vehicle.

In conventional technology, an electric vehicle with a power switch conduction function generally controls the power supply sequence through a plurality of switches, and has a fixed process for electrification, so that the electric vehicle can run normally with a proper power supply.

However , if only a specific power-on process is set, for example: when the normal battery power is low, the control unit still controls the power load switch to connect the vehicle load with the normal battery, so that the vehicle lights are lit, then It will additionally cause a voltage drop, which may lead to insufficient voltage controlled by a switch in the form of a relay or a metal-oxide-semiconductor field-effect transistor, resulting in the inability to control the conduction of the switch, and thus the failure to start the vehicle normally.

Because of this, the inventor, in the spirit of active invention, thought hard about a control method of a power supply system that could solve the above-mentioned problems, and finally completed the present invention after several researches and experiments.

The main purpose of the present invention is to provide a control method for a power supply system, by pre-detecting the power state of the regular battery of an electric vehicle, adjusting the use sequence of the power supply system, so as to ensure that the regular battery power is sufficient and the load power switch can be turned on. To withstand the power consumption of the vehicle load, avoiding the failure to provide enough power for the control unit to wake up the main battery due to excessive consumption, and thus unable to start the vehicle normally.

In order to achieve the above object, the control method of the power supply system of the present invention is applied to an electric vehicle, and the electric vehicle includes a main battery, a motor controller, a voltage reducing device, a permanent battery and a vehicle load. The main battery is connected to a control unit by communication; the motor controller is electrically connected to a motor and the main battery; Controlled by the control unit; the load of the vehicle is electrically connected to the step-down device and the normal battery with a load power switch, and the conduction of the load power switch is controlled by the control unit. Wherein, the control method of the electric vehicle power supply system includes the following steps: (A1) The electric vehicle is started by the driver, and step (B1) is executed; (B1) The control unit that receives the start signal will wake up the main battery, start to precharge the motor controller capacitor and the voltage drop device, and judge whether the voltage of the normal battery is greater than a normal voltage, and if so, execute step (C1), if Otherwise execute step (C2); (C1) turning on the load power switch, so that the vehicle load starts to operate normally, and execute step (D1); (D1) judging whether the pre-charging of the main battery is completed, if so, execute step (E1), otherwise repeat step (D1); (E1) Turn on the charging power switch, so that the power supply of the step-down device can charge the normal battery and supply it to the vehicle load, and perform step (F); (C2) judging whether the precharging of the main battery is completed, if so, execute step (D2), otherwise repeat step (C2); (D2) Turn on the charging power switch, so that the power supply of the step-down device can preferentially charge the normal battery, and execute step (E2) after a delay time; (E2) turning on the load power switch, so that the vehicle load starts to operate normally, and execute step (F); and (F) The electric vehicle is operating normally.

Another power system control method of the present invention is used in an electric vehicle, which includes a main battery, a motor controller, an on-board computer, a voltage reducing device, a permanent battery and a vehicle load. The main battery is connected to a control unit by communication; the motor controller is electrically connected to a motor and the main battery; the trip computer is connected to the main battery and the motor controller by communication; the voltage reducing device is electrically connected to the main battery; For the device, the conduction of the charging power switch is controlled by the control unit; the vehicle load is electrically connected to the step-down device and the normal battery with a load power switch, and the conduction of the load power switch is controlled by the control unit. Wherein, the control method of the electric vehicle power supply system includes the following steps: (A2) The electric vehicle is started without the driver, and the trip computer is scheduled to enter the detection state, and step (B2) is executed; (B2) Judging whether the voltage of the normal battery is less than an abnormal voltage, if so, execute (C3), otherwise execute step (H); (C3) The control unit will wake up the main battery, start pre-charging the motor controller capacitor and the voltage reducing device, and judge whether the main battery is pre-charged, if so, execute step (D3), if not, repeat step (C3); (D3) turn on the charging power switch, so that the power supply of the step-down device can charge the normal battery, and perform step (E3); (E3) Judging whether the voltage of the constant-time battery is greater than a suitable voltage, if so, execute step (G), otherwise repeat step (E3); (G) turn off the charging power switch and the main battery, and perform step (H); and (H) The trip computer goes into sleep mode, waiting for the next schedule inspection.

The above-mentioned main battery can be a 48-volt lead-acid battery, lithium battery or energy capacitor; the above-mentioned regular battery can be a 12-volt lead-acid battery, lithium battery or energy capacitor, which is used to store electric energy and is not limited to a specific battery type.

The aforementioned charging power switch and load power switch can be relays, MOSFETs, IGBTs or SCRs respectively, and are not limited to specific switch types.

The above-mentioned control unit can wake up the main battery through a communication signal or a voltage signal, so as to perform a subsequent pre-charging operation, so as to facilitate the normal start of the electric vehicle.

The above-mentioned normal voltage can be 10 volts; the above-mentioned abnormal voltage can be 8 volts; the above-mentioned suitable voltage can be 11 volts, and there may be different voltage judgment thresholds due to the use of different electric energy storage devices, and are not limited to specific voltage judgments threshold.

The above summary and the following detailed description are exemplary in order to further illustrate the scope of the present invention. Other purposes and advantages of the present invention will be described in the subsequent description and illustrations.

Please refer to FIG. 1 , which is a system configuration diagram of the electric vehicle of the present invention. The figure shows an electric vehicle 1 , which mainly includes a main battery 2 , a motor controller 3 , a voltage reducing device 4 , a permanent battery 5 , a vehicle load 6 and an on-board computer 7 .

In this embodiment, the main battery 2 uses a 48-volt lithium battery, but it is not limited thereto, and other forms of electric energy storage devices such as lead-acid batteries or energy capacitors can also be used to provide power to the motor controller 3 . The main battery 2 is communicatively connected to a control unit 21. As shown in the figure, the control unit 21 of this embodiment is set in the trip computer 7, but it is not limited thereto. It is integrated with the motor controller 3 or other devices. Wherein, the control unit 21 uses the regular battery 5 as its power source, and can wake up the main battery 2 through a communication signal or a voltage signal, so as to perform subsequent precharging operations and communicate with the motor controller 3, so as to facilitate the normal operation of the electric vehicle. start up. The motor controller 3 is electrically connected to a motor 31 and the main battery 2 for driving the motor 31 to generate forward power of the vehicle. The trip computer 7 is a vehicle control unit (Vehicle Control Unit, VCU), which communicates with the main battery 2 and the motor controller 3, and serves as a comprehensive coordinated control of the electric vehicle 1, and performs scheduling inspection of the permanent battery 5. This implementation The communication connection mentioned in the example is through the Controller Area Network Bus (CANbus) for data transmission. In this embodiment, the step-down device 4 is a DC-DC converter electrically connected to the main battery 2, so it can convert the voltage of 48 volts to 12 volts to supplement the power of the normal battery 5.

In this embodiment, the regular battery 5 is a lithium battery of 12 volts, but it is not limited thereto. Other forms of electric energy storage devices such as lead-acid batteries or energy capacitors can also be used. The regular battery 5 is a charging power supply. The switch S1 is electrically connected to the step-down device 4, the charging power switch S1 is responsible for conducting the two ends of the above-mentioned device, and the power supply of the control step-down device 4 can be turned on to charge the normal battery 5 through the charging power switch S1, and the conduction of the control power switch S1 and No is controlled by the control unit 21 . In addition, the vehicle load 6 can be components such as lamps or instruments of the electric vehicle 1, and is electrically connected to the step-down device 4 and the regular battery 5 with a load power switch S2, and the load power switch S2 can control the constant power supply 5 to provide the vehicle load 6 with The power supply of 12 volts enables the vehicle load 6 such as the lamp system and other peripheral devices to operate normally, and the conduction of the load power switch S2 is controlled by the control unit 21 . Among them, the charging power switch S1 and the load power switch S2 can be relays, metal oxide half-field-effect transistors (MOSFETs), insulated gate bipolar transistors (IGBTs) or silicon-controlled rectifiers (SCRs), and are not limited to specific switches. type.

Please refer to FIG. 2 , which is a flow chart of the control method of the power supply system of the electric vehicle according to the first embodiment of the present invention. As shown in the figure, the control method of the electric vehicle power supply system of the present invention includes the following steps: (A1) The electric vehicle 1 is started by the driver, and step (B1) is executed. When the driver starts the vehicle through a key or a switch, start The signal will go to the control unit 21 which is always live. (B1) The control unit 21 that receives the starting signal will wake up the main battery 2 through the aforementioned controller area network (CANbus) communication system, so that the main battery 2 starts to precharge the capacitor of the motor controller 3 and the voltage reducing device 4, and Judging whether the voltage of the battery 5 is greater than a normal voltage, if so, execute step (C1), otherwise execute step (C2), in the present embodiment, the normal voltage is 10 volts, but not limited thereto, also The numerical value can be changed according to the capacity of the permanent battery 5 .

(C1) Turn on the load power switch S2 to start the normal operation of the vehicle load 6, such as lighting the front and rear lamps of the electric vehicle 1, which can give priority to the warning function of the front and rear vehicles, and execute step (D1). (D1) Determine whether the pre-charging of the main battery 2 is completed. In this embodiment, it can be judged that the pre-charging is completed when the power reaches more than 42 volts. If so, perform step (E1), otherwise repeat step (D1). (E1) Turn on the charging power supply switch S1, so that the power supply of the step-down device 4 can charge the normal battery 5 and supply it to the vehicle load 6, and perform step (F). Because the power is small during pre-charging, if it is during pre-charging That is, if the charging power switch S1 is turned on, the pre-charging function of the main battery 2 cannot be completed, so it must be determined that the pre-charging is indeed completed before the charging power switch S1 can be turned on. (F) The electric vehicle runs normally, and the start-up process of the electric vehicle is completed when the voltage of the battery 5 is sufficient at all times.

However, when the control unit 21 judges that the voltage of the constant-time battery 5 is abnormal (below 10 volts), it needs to first (C2) judge whether the pre-charging of the main battery 2 is completed, and if so, execute step (D2), otherwise repeat Execute step (C2). (D2) Turn on the charging power switch S1, so that the power supply of the step-down device 4 can preferentially charge the normal battery 5, and execute step (E2) after a delay time, the delay time can be 0-2 seconds. (E2) Turn on the load power switch S2 to make the vehicle load 6 start to operate normally, and execute step (F). (F) The electric vehicle is running normally, and the start-up process of the electric vehicle is completed when the voltage of the battery 5 is usually insufficient.

With the above-mentioned process design, the advantage of the present invention is that when the battery 5 is always fully charged, the vehicle load 6 can be started preferentially during the vehicle starting process, so as to achieve the shortest time to start the vehicle and light the front and rear lights to give priority to the warning of the front and rear vehicles Function; relatively, when the power of the normal battery 5 is insufficient, and it may not be possible to turn on the vehicle load 6 first and then turn on the charging power switch S1, the charging power switch S1 is preferentially turned on, so that the normal battery 5 can be charged first and the load power switch S2 is turned on , then use the power output from the step-down device 4 to provide the vehicle load 6 for use.

Please refer to FIG. 3 , which is a flow chart of the control method of the power supply system of the electric vehicle according to the second embodiment of the present invention. As shown in the figure, the control method of the electric vehicle power supply system of the present invention includes the following steps: (A2) The electric vehicle 1 is not started by the driver, and the trip computer 7 is scheduled to enter the detection state, and step (B2) is executed, when If the electric vehicle 1 has not been used for a long time, the voltage of the battery 5 is often seriously insufficient due to the self-consumption of the battery 5 or the slow loss of the control unit 21, it is necessary to set another detection schedule. 1 In the state of not starting, the power detection is carried out regularly. (B2) Judging whether the voltage of the battery 5 is less than an abnormal voltage at all times, if so, execute (C3), if otherwise execute step (H), the abnormal voltage is 8 volts in the present embodiment, but not limited thereto, Also can change numerical value according to the electric capacity of always-time battery 5. (C3) The control unit 21 will wake up the main battery 2, start precharging the capacitor of the motor controller 3 and the voltage drop device 4, and judge whether the precharging of the main battery 2 is completed, if so, execute step (D3), otherwise repeat the step (C3). (D3) Turn on the charging power supply switch S1 so that the power supply of the step-down device 4 can charge the normal battery 5, avoiding the power depletion of the normal battery 5 and making it impossible to start the electric vehicle 1, and perform step (E3). (E3) Judging whether the voltage of the constant-time battery 5 is greater than a suitable voltage, if so, execute step (G), otherwise repeat step (E3), the described suitable voltage is 11 volts in the present embodiment, but it is not regarded as The value can also be changed according to the capacity of the battery 5 at all times. (G) The control unit 21 will command to turn off the charging power switch S1 and the main battery 2 to complete the charging operation of the electric vehicle 1 to the permanent battery 5 when the electric vehicle 1 is not started, and execute step (H). (H) The trip computer 7 goes into sleep mode, and waits for the next schedule detection.

Through the above process design, the control unit 21 of the present invention can set a schedule to check the voltage of the normal battery 5 according to different models or different capacities of the normal battery 5, for example, daily, weekly or other length of time can be set. Scheduling can effectively avoid the problem that the electric vehicle 1 is not used for a long time, so that the power of the battery 5 is always exhausted and the vehicle cannot be started.

The above-mentioned embodiments are only examples for convenience of description, and the scope of rights claimed by the present invention should be based on the scope of the patent application, rather than limited to the above-mentioned embodiments.

1: Electric vehicles 2: Main battery 21: Control unit 3: Motor controller 31: motor 4: Pressure reducing device 5: Normal battery 6: Vehicle load 7: Trip computer S1: charging power switch S2: load power switch A1-H: Steps

Fig. 1 is a system configuration diagram of the electric vehicle of the present invention. Fig. 2 is a flow chart of the control method of the power supply system of the electric vehicle according to the first embodiment of the present invention. FIG. 3 is a flow chart of the control method of the power supply system of the electric vehicle according to the second embodiment of the present invention.

A1-F: Steps

Claims (9)

A control method of a power supply system is used in an electric vehicle, and the electric vehicle includes: A main battery, communication connection with a control unit; a motor controller electrically connected to a motor and the main battery; a voltage reducing device electrically connected to the main battery; A permanent battery is electrically connected to the step-down device through a charging power switch, and the conduction of the charging power switch is controlled by the control unit; and A vehicle load, which is electrically connected to the step-down device and the permanent battery through a load power switch, and the conduction of the load power switch is controlled by the control unit; Wherein, the control method of the electric vehicle power supply system includes the following steps: (A1) The electric vehicle is started by the driver, and step (B1) is executed; (B1) The control unit that receives the starting signal will wake up the main battery, start precharging the motor controller capacitor and the voltage drop device, and judge whether the voltage of the normal battery is greater than a normal voltage, and if so, execute the step ( C1), if otherwise, execute step (C2); (C1) turning on the load power switch, so that the vehicle load starts to operate normally, and execute step (D1); (D1) judging whether the pre-charging of the main battery is completed, if so, execute step (E1), if not, repeat step (D1); (E1) Turn on the charging power switch so that the power supply of the step-down device can charge the normal battery and supply to the vehicle load, and perform step (F); (C2) judging whether the pre-charging of the main battery is completed, if so, execute step (D2), otherwise repeat step (C2); (D2) Turn on the charging power switch, so that the power supply of the step-down device can charge the normal battery first, and execute step (E2) after a delay time; (E2) turning on the load power switch to make the vehicle load start to operate normally, and execute step (F); and (F) The electric vehicle is operating normally. A control method of a power supply system is used in an electric vehicle, and the electric vehicle includes: A main battery, communication connection with a control unit; a motor controller electrically connected to a motor and the main battery; A vehicle computer, communicating with the main battery and the motor controller; a voltage reducing device electrically connected to the main battery; A permanent battery is electrically connected to the step-down device through a charging power switch, and the conduction of the charging power switch is controlled by the control unit; and A vehicle load, which is electrically connected to the step-down device and the permanent battery through a load power switch, and the conduction of the load power switch is controlled by the control unit; Wherein, the control method of the electric vehicle power supply system includes the following steps: (A2) The electric vehicle has not been started by the driver, and the trip computer is scheduled to enter the detection state, and step (B2) is executed; (B2) judging whether the voltage of the normal battery is less than an abnormal voltage, if so, execute (C3), otherwise execute step (H); (C3) The control unit will wake up the main battery, start pre-charging the motor controller capacitor and the voltage drop device, and judge whether the main battery is pre-charged, if so, perform step (D3), if not, repeat the step (C3); (D3) turn on the charging power switch, so that the power supply of the step-down device can charge the normal battery, and perform step (E3); (E3) judging whether the voltage of the permanent battery is greater than an appropriate voltage, if so, execute step (G), if not, repeat step (E3); (G) turning off the charging power switch and the main battery, and performing step (H); and (H) The trip computer goes into sleep mode, waiting for the next schedule detection. The control method of the power supply system according to claim 1 or claim 2, wherein the main battery is a 48-volt lead-acid battery, lithium battery or energy capacitor. The control method of the power supply system as described in claim 1 or claim 2, wherein the permanent battery is a 12-volt lead-acid battery, a lithium battery or an energy capacitor. The control method of the power supply system as described in claim 1 or claim 2, wherein the charging power switch and the load power switch are respectively a relay, a metal oxide semiconductor field effect transistor (MOSFET), an insulated gate bipolar transistor (IGBT) ) or Silicon Controlled Rectifier (SCR). The control method of the power supply system according to claim 1 or claim 2, wherein the control unit wakes up the main battery through a communication signal or a voltage signal. The control method of the power system according to claim 1, wherein the normal voltage is 10 volts. The control method of the power system according to claim 2, wherein the abnormal voltage is 8 volts. The control method of the power system according to claim 2, wherein the suitable voltage is 11 volts.

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