Power supply system of electric vehicle and power supply control method

Abstract

The invention relates to a power supply system of an electric vehicle and a power supply control method, the power supply system comprises a power battery, a first direct current converter, a motor controller, a low voltage battery and a power relay, the first direct current converter converts an output high voltage of the first direct current converter into a first direct current voltage, and the motor controller is connected with the low voltage battery. A second direct current converter can be further arranged in the motor controller; when the motor controller judges that the first direct-current voltage output by the first direct-current converter is not within a preset range, the low-voltage battery or the second direct-current converter can still supply power to a power relay to enable the power relay to maintain conduction, so that the motor controller receives the output high voltage through the power relay to drive a motor to operate, and the motor is driven to operate. Therefore, the electric vehicle does not lose power suddenly when the first direct current converter is abnormal, and a rider has enough time to carry out emergency response.

Description

Technical Field

[0001] The present invention relates to a power supply system for an electric vehicle, and more particularly to a power supply system capable of maintaining normal operation of a motor controller when a DC converter in the vehicle fails. Background Art

[0002] Please refer to Figure 7 As shown, the existing electric vehicle power supply system mainly includes a power battery 100, a motor controller 200, a power relay 300, a DC converter 200, etc. The power relay 300 is connected between the motor controller 200 and the power battery 100. When the power relay 300 is switched to the on state, the power inside the power battery 100 can be transmitted to the motor controller 200, so that the motor controller 200 controls the operation of a motor M of the electric vehicle; on the contrary, when the power relay 300 is switched to the off state, the power of the power battery 100 cannot be provided to the motor controller 200, and the motor M cannot operate.

[0003] The DC converter 200 is used to convert the voltage output by the power battery 100 into a low-level voltage, and the low-level voltage is used to supply the load 500 on the electric vehicle. In addition, the DC converter 200 further outputs an excitation current to control whether the power relay 300 is switched to a conducting state. Therefore, when the DC converter 200 fails and cannot output the excitation current, the power relay 300 will become an open circuit state, causing the motor controller 200 to be unable to operate and the motor M of the electric vehicle to fail to operate normally.

[0004] For example, when a user is riding an electric vehicle, if the DC converter 200 suddenly fails, the power relay 300 will be turned into an open circuit state. Even if the power battery 100 can still supply power to the entire vehicle normally, the motor M will still stop running due to the open circuit of the power relay 300. However, the electric vehicle will suddenly lose power, and the user may panic. If an emergency response is not taken, it may easily cause a traffic accident. Summary of the invention

[0005] [Technical problem to be solved by the invention]

[0006] In view of the fact that when the DC converter in the existing electric vehicle fails, the motor will stop running and easily cause riding accidents, the present invention therefore proposes a "power supply system and power supply control method for an electric vehicle" that can keep the motor running continuously when the DC converter fails.

[0007] [Technical means to solve the problem]

[0008] To overcome the above problems, according to a technical solution of the present invention, the present invention provides a power supply system for an electric vehicle, comprising:

[0009] A power battery, providing an output high voltage;

[0010] a first DC converter, connected to the power battery, and converting the output high voltage into a first DC voltage;

[0011] A low voltage battery outputs a voltage;

[0012] A motor controller is connected to the power battery through an electric relay, and utilizes the output high voltage of the power battery to drive a motor to operate. The motor controller includes:

[0013] a second DC converter, the DC converter outputting a second DC voltage;

[0014] wherein the power relay is connected to the first DC converter via a first diode, and the power relay is connected to the low-voltage battery via a second diode;

[0015] When the motor controller determines that the first DC voltage is not within a preset range, the power relay is maintained in a conducting state by utilizing the second DC voltage output by the low-voltage battery.

[0016] The present invention provides an electric vehicle power supply control method for an electric vehicle, wherein the electric vehicle comprises a motor, a power battery, a power relay, a motor controller, a first DC converter, and a low-voltage battery. The power supply control method comprises:

[0017] Connecting the output terminal of the first DC converter and the output terminal of the low-voltage battery to the power relay;

[0018] The motor controller detects a first DC voltage output by the first DC converter and determines whether the first DC voltage is within a preset range;

[0019] When the first DC voltage is not within the preset range, the motor controller determines that the first DC converter is abnormal;

[0020] When the first DC converter is judged to be abnormal, the low-voltage battery provides a current to the power relay, and the motor controller controls the power relay to be continuously turned on, so that the power relay receives the output voltage of the power battery to maintain the operation of the motor.

[0021] According to another technical solution of the present invention, the power supply system of the electric vehicle of the present invention comprises:

[0022] A power battery, providing an output high voltage;

[0023] a first DC converter, connected to the power battery, and converting the output high voltage into a first DC voltage;

[0024] A motor controller is connected to the power battery through an electric relay, and utilizes the output high voltage of the power battery to drive a motor to operate. The motor controller includes:

[0025] a second DC converter, the DC converter outputting a second DC voltage;

[0026] wherein the power relay is connected to the first DC converter via a first diode, and the power relay is connected to the second DC converter via a second diode;

[0027] When the motor controller determines that the first DC voltage is not within a preset range, the power relay is maintained in a conducting state by utilizing the second DC voltage output by the second DC converter.

[0028] The present invention provides an electric vehicle power supply control method for an electric vehicle, wherein the electric vehicle comprises a motor, a power battery, a power relay, a motor controller, a first DC converter, and a low-voltage battery, wherein the motor controller comprises a second DC converter, and the power supply control method comprises:

[0029] Connecting the output terminal of the first DC converter and the output terminal of the second DC converter to the power relay;

[0030] The motor controller detects a first DC voltage output by the first DC converter and determines whether the first DC voltage is within a preset range;

[0031] When the first DC voltage is not within the preset range, the motor controller determines that the first DC converter is abnormal;

[0032] When the first DC converter is determined to be abnormal, the second DC converter provides a current to the power relay, and the motor controller controls the power relay to be continuously turned on, so that the power relay receives the output voltage of the power battery to maintain the operation of the motor.

[0033] [Effects of the invention]

[0034] When the first DC converter of the electric vehicle is abnormal, the present invention can utilize the low-voltage battery inside the electric vehicle or the second DC converter in the motor controller to continue to supply power to the power relay, so that the power relay remains conductive. In this way, the power battery can supply power to the motor controller via the power relay, so that the motor controller can continue to drive the motor of the electric vehicle to operate, so that the electric vehicle will not suddenly lose power during riding. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1: Circuit block diagram of the first embodiment of the present invention.

[0036] Figure 2 : Circuit operation diagram of the first embodiment of the present invention.

[0037] Figure 3 : Flowchart of the control method of the circuit of the first embodiment of the present invention.

[0038] Figure 4 : Circuit block diagram of the second embodiment of the present invention.

[0039] Figure 5 : Circuit operation diagram of the second embodiment of the present invention.

[0040] Figure 6 : Flowchart of the control method of the circuit of the second embodiment of the present invention.

[0041] Figure 7 : Circuit block diagram of the power system of an existing electric vehicle.

[0042] Reference numerals list

[0043] 10: Power battery

[0044] 20: First DC converter

[0045] 30: Low voltage battery

[0046] 40: Power relay

[0047] 41: Excitation coil

[0048] 411: First End

[0049] 412: Second End

[0050] 42: Switch

[0051] 50: Motor controller

[0052] 51: Microprocessor

[0053] 52: Control switch

[0054] 53: Detection line

[0055] 54: Second DC converter

[0056] 540: Resettable Fuse

[0057] 55: Power module

[0058] 56: Internal relay

[0059] 561: Internal coil

[0060] 562: Internal switch

[0061] 60: Instrument

[0062] 100: Power battery

[0063] 200: Motor controller

[0064] 300: Power relay

[0065] 400: DC converter

[0066] 500: Load

[0067] D1: The first diode

[0068] D2: The second diode

[0069] D3: The third diode

[0070] I: Excitation current

[0071] M: Motor

[0072] V H :Output voltage

[0073] V1: First DC voltage

[0074] V2: second DC voltage. DETAILED DESCRIPTION

[0075] Please refer to Figure 1 2 is a block diagram of a first embodiment of a power system for an electric vehicle of the present invention. The present invention includes a power battery 10, a first DC converter 20, a low-voltage battery 30, a power relay 40, a motor controller 50, and a motor M.

[0076] The power battery 10 is used to provide the power source required by the electric vehicle. The power battery 10 can be a high-capacity battery pack composed of lithium batteries. A high-level output voltage V can be output at the output end of the power battery 10. H , for example, the output voltage is 48V.

[0077] The first DC converter 20 is connected to the power battery 10 to receive the output voltage V H and the output voltage V H Converted into a first DC voltage V1. In one embodiment, the first DC voltage V1 is an output voltage of 12V / 12A, and its output power is about 150W, which can be supplied to the load on the electric vehicle, such as the headlights, brake lights, etc. on the electric vehicle.

[0078] The output voltage of the low-voltage battery 30 is relatively lower than the output voltage V of the power battery 10. HIn one embodiment, the low voltage battery 30 is a lead-acid battery that outputs approximately 12V.

[0079] The power relay 40 includes an excitation coil 41 and a switch 42, wherein the excitation coil 41 has a first end 411 and a second end 412, wherein the first end 411 is connected to the motor controller 50, and the second end 412 is connected to the cathodes of a first diode D1 and a second diode D2, wherein the anode of the first diode D1 is connected to the first DC converter 20, and the anode of the second diode D2 is connected to the low-voltage battery 30. The switch 42 is connected between the power battery 10 and the motor controller 50, and when an excitation current passes through the excitation coil 41, the switch 42 is in a closed state to allow the output voltage V of the power battery 10 to be H The voltage is transmitted to the motor controller 50 ; on the contrary, when there is no excitation current, the switch 42 is in the open state.

[0080] In this embodiment, the motor controller 50 includes a microprocessor 51, a control switch 52, a detection circuit 53, a second DC converter 54, and a power module 55. The detection circuit 53 is connected to the first DC converter 20. The microprocessor 51 senses the state of the first DC converter 20 through the detection circuit 53 to determine whether the first DC converter 20 is operating normally. In this embodiment, the detection circuit 23 is a voltage-dividing circuit composed of resistors connected in series. A voltage-dividing value is generated according to the output voltage of the first DC converter 20. The microprocessor 51 determines whether the first DC converter 20 is abnormal according to the voltage-dividing value. When it is determined that the first DC voltage V1 output by the first DC converter 20 is within a preset range (e.g., 8V to 16V), it means that the first DC converter 20 is operating normally; on the contrary, if the first DC voltage V1 is not within the preset range, it is determined to be abnormal.

[0081] The microprocessor 51 also outputs a control signal to the control switch 52 to control its conduction or disconnection, wherein the control switch 52 can be a metal oxide semiconductor field effect transistor (MOSFET) having a gate, a drain and a source. The gate of the control switch 52 is connected to the microprocessor 51, the drain is connected to the power relay 40, and the source is grounded.

[0082] The second DC converter 54 is used to convert the output voltage V HThe second DC voltage V2 is converted into a second DC voltage V2, which can be provided to the load on the electric vehicle, for example, to the meter 60. In one embodiment, the second DC converter 54 is connected to the load via a resettable fuse 540 to provide overload protection. The second DC converter 54 can convert the 48V voltage into a 12V / 1A voltage, and its power is about 12W. The power module 55 is connected to the power relay 40. When the power relay 40 is turned on, the power module 55 receives the high-level voltage of the power battery 10 to drive the motor M to operate.

[0083] In terms of circuit operation, the motor controller 50 continuously detects whether the first DC voltage V1 of the first DC converter 20 is within a preset range. If the first DC voltage V1 is maintained within the preset range, it means that the first DC converter 20 is normal. At least the first DC converter 20 can output a current through the excitation coil 31, so that the switch 32 is maintained closed. Therefore, the output voltage V H The power will be transmitted to the power module 55 of the motor controller 50 through the closed switch 32, so that the motor M can operate normally.

[0084] like Figure 2 As shown, when the first DC voltage V1 of the first DC converter 20 is not within the preset range, it means that the first DC converter 20 is abnormal, and the motor controller 50 controls the meter 60 to display a fault message to remind the rider. At this time, the low-voltage battery 30 still outputs an excitation current I to the power relay through the second diode D2, so that the switch 32 remains closed, so the output voltage V H The power can still be transmitted to the power module 55 of the motor controller 50, and the microprocessor 51 will not control the power module 55 to stop supplying power, so the motor M is still maintained to operate normally.

[0085] Please refer to Figure 3 As shown, the control method of the first embodiment of the present invention includes the following steps:

[0086] S301: The motor controller 50 continuously detects a first DC voltage output by the first DC converter 20 to determine whether the first DC voltage is within a preset range;

[0087] S302: When the first DC voltage is not within the preset range, the motor controller 50 determines that the first DC converter 20 is abnormal;

[0088] S303: The first DC converter 20 is judged to be abnormal, and the low-voltage battery 50 provides a current to the power relay 30, and the motor controller 50 controls the power relay 30 to be continuously turned on, so that the power relay 30 receives the output voltage of the power battery 10 to maintain the operation of the motor M.

[0089] Please refer to Figure 4 , which is a second embodiment of the present invention, comprises a power battery 10, a first DC converter 20, a power relay 40, a motor controller 50 and a motor M. The functions and components of the power battery 10, the first DC converter 20 and the power relay 40 are substantially the same as those of Figure 1 The same as the first embodiment.

[0090] The difference from the first embodiment lies in the internal circuit of the motor controller 50 , and the anode of the second diode D2 is connected to the output end of the second DC converter 54 .

[0091] The motor controller 50 includes a microprocessor 51 , a control switch 52 , a detection circuit 53 , a second DC converter 54 , a power module 55 and an internal relay 56 .

[0092] The detection circuit 53 is connected to the first DC converter 20. The microprocessor 51 senses the state of the first DC converter 20 through the detection circuit 53 to determine whether the first DC converter 20 is operating normally. The detection circuit 23 in this embodiment is a voltage divider circuit composed of a plurality of resistors connected in series. A voltage divider value is generated according to the output voltage of the first DC converter 20. The microprocessor 51 determines whether the first DC converter 20 is abnormal according to the voltage divider value. When it is determined that the first DC voltage V1 output by the first DC converter 20 is within a preset range (e.g., 8V to 16V), it means that the first DC converter 20 is operating normally. On the contrary, if the first DC voltage V1 is not within the preset range, it is abnormal.

[0093] The microprocessor 51 also outputs a control signal to the control switch 52 to control its conduction or disconnection, wherein the control switch 52 can be a bipolar junction transistor (BJT) having a base, a collector and an emitter. The base of the control switch 52 is connected to the microprocessor 51, the collector is connected to the internal relay 56, and the source is grounded.

[0094] The second DC converter 54 converts the output voltage V of the power battery 10 HThe second DC voltage V2 is converted into a second DC voltage V2, which can be provided to the load on the electric vehicle, for example, to the meter 60. In one embodiment, the second DC converter 54 can convert the 48V voltage into a 12V / 1A voltage, and its power is about 12W. In this embodiment, the output end of the second DC converter 54 is connected to the excitation coil 41 of the power relay 40 through the second second electrode body D2.

[0095] The power module 55 is connected to the power relay 40 . When the power relay 40 is turned on, the power module 55 receives the high voltage of the power battery 10 to drive the motor M to operate.

[0096] The internal relay 56 has an internal coil 561 and an internal switch 562, one end of the internal coil 561 is connected to the collector of the control switch 52, and the other end is connected to the second DC converter 54; the internal switch 562 is controlled by the internal coil 561 to be closed, wherein one end of the internal switch 562 is simultaneously connected to the first end 411 of the excitation coil 41, and is connected to the output end of the first DC converter 20 via a third diode D3.

[0097] In the circuit operation part, the motor controller 50 continuously detects whether the first DC voltage V1 output by the first DC converter 20 is within a preset range. If the first DC voltage V1 is maintained within the preset range, it means that the first DC converter 20 is normal. The microprocessor 51 turns on the control switch 52, so that the second DC converter 54 outputs a current through the internal coil 561, so that the internal switch 562 is closed and connected in series with the excitation coil 31. In addition, the first DC converter 20 can at least provide an excitation current to the excitation coil 31 in the power relay 30, so that the switch 32 is maintained closed, so that the output voltage V of the power battery 10 is H The power can be transmitted to the power module 55 of the motor controller 50 via the closed switch 32, so that the motor M can operate normally.

[0098] like Figure 5 As shown, when the output voltage V of the first DC converter 20 H If the voltage is not within the preset range, it means that the first DC converter 20 is abnormal, and the motor controller 50 will control the meter 60 to display a fault message to remind the rider. At this time, the microprocessor 51 still turns on the control switch 52, so that the second DC converter 54 outputs a current through the internal coil 561, so that the internal switch 562 is closed and connected in series with the excitation coil 31. The second DC converter 54 can at least provide an excitation current I to the excitation coil 31 in the power relay 30, so that the switch 32 remains closed, so the output voltage V of the power battery 10 is HThe power can be transmitted to the power module 55 of the motor controller 50 through the closed switch 32, and the microprocessor 51 will not control the power module 55 to stop supplying power, so the motor M is still maintained to run normally.

[0099] Please refer to Figure 6 As shown, the control method of the circuit of the second embodiment of the present invention includes the following steps:

[0100] S601: The motor controller 50 continuously detects a first DC voltage output by the first DC converter 20, and compares whether the first DC voltage is within a preset range;

[0101] S602: When the first DC voltage is not within the preset range, the motor controller 50 determines that the first DC converter 20 is abnormal, and controls the meter 60 to display a fault message;

[0102] S603: When the first DC converter 20 is determined to be abnormal, the second DC converter 54 provides a current to keep the power relay 30 turned on, and the motor controller 50 continues to obtain the output voltage V of the power battery 10 through the power relay 30. H , to control the motor M to maintain operation.

[0103] In summary, according to the technical solution of the present invention, even if an abnormality occurs in the first DC converter 20 on the electric vehicle, the low-voltage battery 30 or the second DC converter 54 in the motor controller 50 can still provide the excitation current to the power relay 40, so that the power relay 40 remains on and closed, allowing the power battery 10 to normally supply power to the motor controller 50. For the rider of the electric vehicle, during the riding process, the instrument 60 can be used to receive a warning message that an abnormality has occurred in the first DC converter 20. As long as the power battery 10 is still normal, the electric vehicle will not lose power, and the rider still has enough time to take emergency measures to reduce the occurrence of traffic accidents.

Claims

1. A power supply system for an electric vehicle, characterized in that: Contains: A power battery, providing an output high voltage; a first DC converter, connected to the power battery, and converting the output high voltage into a first DC voltage; A low voltage battery, outputting a voltage; A motor controller is connected to the power battery through an electric relay, and utilizes the output high voltage of the power battery to drive a motor to operate. The motor controller includes: a microprocessor; a second DC converter, wherein the second DC converter outputs a second DC voltage; wherein the power relay is connected to the first DC converter via a first diode, and the power relay is connected to the low-voltage battery via a second diode; When the motor controller determines that the first DC voltage is not within a preset range, the power relay is maintained in a conducting state using the second DC voltage output by the low-voltage battery.

2. A power supply system for an electric vehicle, characterized in that: Contains: A power battery, providing an output high voltage; a first DC converter, connected to the power battery, and converting the output high voltage into a first DC voltage; A motor controller is connected to the power battery through an electric relay, and utilizes the output high voltage of the power battery to drive a motor to operate. The motor controller includes: a microprocessor; a second DC converter, wherein the second DC converter outputs a second DC voltage; wherein the power relay is connected to the first DC converter via a first diode, and the power relay is connected to the second DC converter via a second diode; When the motor controller determines that the first DC voltage is not within a preset range, the power relay is maintained in a conducting state by utilizing the second DC voltage output by the second DC converter.

3. The power supply system of an electric vehicle according to claim 1 or 2, characterized in that: The motor controller includes a power module, and the power module receives the output high voltage through the power relay to drive the motor to operate.

4. The power supply system of an electric vehicle according to claim 1 or 2, characterized in that: The power relay comprises: a switch connected between the power battery and the motor controller; An excitation coil is used to control whether the switch is closed and turned on. The excitation coil has a first end and a second end. The first end is connected to the motor controller, and the second end is connected to the cathode of the first diode and the second diode.

5. The power supply system of an electric vehicle according to claim 1 or 2, characterized in that: The motor controller includes a detection circuit, and the detection circuit senses the first DC voltage of the first DC converter; the microprocessor determines whether the first DC voltage is within the preset range according to the sensing result of the detection circuit.

6. The power supply system of an electric vehicle according to claim 1, characterized in that: The motor controller includes a control switch connected to the power relay; The microprocessor controls the control switch to be turned on, so that an excitation current passes through the power relay to turn on the power relay.

7. The power supply system of an electric vehicle according to claim 2, characterized in that: The motor controller further comprises: an internal relay, comprising an internal switch and an internal coil, wherein the internal switch is connected to the power relay; one end of the internal coil is connected to the second DC converter; a control switch connected in series with the other end of the internal coil; The microprocessor controls the control switch to be turned on, so that a current passes through the internal coil to turn on the internal switch, and an excitation current passes through the power relay to turn on the power relay.

8. The power supply system of an electric vehicle according to claim 1 or 2, characterized in that: The motor controller is connected to a meter. When the first DC voltage is not within the preset range, the motor controller controls the meter to display a fault message.

9. A power supply control method for an electric vehicle, characterized in that: The electric vehicle comprises a motor, a power battery, a power relay, a motor controller, a first DC converter, and a low-voltage battery, wherein the output end of the first DC converter and the output end of the low-voltage battery are connected to the power relay, and the power supply control method comprises: The motor controller detects a first DC voltage output by the first DC converter, and determines whether the first DC voltage is within a preset range; When the first DC voltage is not within the preset range, the motor controller determines that the first DC converter is abnormal; When the first DC converter is judged to be abnormal, the low-voltage battery provides a current to the power relay, and the motor controller controls the power relay to be continuously turned on, so that the power relay receives the output voltage of the power battery to maintain the operation of the motor.

10. A power supply control method for an electric vehicle, characterized in that: The electric vehicle comprises a motor, a power battery, a power relay, a motor controller, and a first DC converter, wherein the output end of the first DC converter and the output end of the second DC converter are connected to the power relay, the motor controller comprises a second DC converter, and the power supply control method comprises: The motor controller detects a first DC voltage output by the first DC converter, and determines whether the first DC voltage is within a preset range; When the first DC voltage is not within the preset range, the motor controller determines that the first DC converter is abnormal; When the first DC converter is determined to be abnormal, the second DC converter provides a current to the power relay, and the motor controller controls the power relay to be continuously turned on, so that the power relay receives the output voltage of the power battery to maintain the operation of the motor.

11. The power supply control method for an electric vehicle according to claim 9 or 10, characterized in that: The electric vehicle further includes a meter, wherein when the first DC converter is determined to be abnormal, the motor controller controls the meter to display a fault message.

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