CN215452794U

CN215452794U - Standby power supply of vehicle-mounted motor controller

Info

Publication number: CN215452794U
Application number: CN202121091169.4U
Authority: CN
Inventors: 张朝君; 陈雷; 温小伟; 梅友忠; 董大伟
Original assignee: Shanghai Auto Edrive Co Ltd; Shanghai Auto Edrive Engineering Technology Research Center; Shanghai Edrive Co Ltd
Current assignee: Shanghai Auto Edrive Co Ltd; Shanghai Auto Edrive Engineering Technology Research Center; Shanghai Edrive Co Ltd
Priority date: 2021-05-20
Filing date: 2021-05-20
Publication date: 2022-01-07
Anticipated expiration: 2031-05-20

Abstract

The utility model relates to a standby power supply of a vehicle-mounted motor controller, which comprises a high-voltage input port, a low-voltage output port, a flyback transformer, an absorption circuit, a power supply starting circuit, a power supply management chip, a high-voltage MOSFET main switch and a gate pole protection circuit, the high-voltage input port is connected to the vehicle-mounted power battery pack, the positive pole of the input end of the flyback transformer is connected to the positive pole of the high-voltage input port through the absorption circuit, the negative pole of the input end of the flyback transformer is connected to the drain electrode of the high-voltage MOSFET main switch, the grid electrode of the high-voltage MOSFET main switch is connected to the positive pole of the high-voltage input port through the power supply starting circuit, the source electrode of the flyback transformer is connected to the power supply input positive pole of the power supply management chip, the power supply input negative pole of the power supply management chip is connected to the negative pole of the high-voltage input port, the gate pole protection circuit is arranged between the grid electrode and the source electrode of the high-voltage MOSFET main switch, and the output end of the flyback transformer is connected with the low-voltage output port through the rectification circuit. Compared with the prior art, the utility model has the advantages of high integration level, reliable work and the like.

Description

Standby power supply of vehicle-mounted motor controller

Technical Field

The utility model relates to a vehicle-mounted standby power supply, in particular to a standby power supply of a vehicle-mounted motor controller.

Background

The motor controller is used as a core power control system of a modern new energy automobile, if abnormal conditions such as collision and the like occur in high-speed running, the motor controller loses effective control over the permanent magnet synchronous motor, at the moment, the motor stalls, and the counter electromotive force generated by the stator winding is charged to a high-voltage loop through uncontrollable rectification, so that the overvoltage failure of a power system is caused, and potential safety hazards such as fire and the like are even generated. The active short circuit function of the hardware is used as a safety protection function of the electric control system, and potential safety hazards caused by the stalling condition of the motor can be solved.

However, when serious faults such as a collision occur, after the low-voltage power supply which supplies power to the main driving loop in the motor controller fails to work, the IGBT driving circuit in the inverter cannot work normally, and the controller cannot start the active short-circuit protection function of hardware. Therefore, a high-voltage backup power module is urgently needed to be designed to provide a minimum power system for enabling the motor controller to enter a safe working state, and after the motor controller fails and the low-voltage main driving power supply fails, the spare +15V power supply supplies power to the hardware main driving loop, so that the safety protection requirement of the electric control system is met.

SUMMERY OF THE UTILITY MODEL

The utility model aims to provide a standby power supply of a vehicle-mounted motor controller, which adopts a mode of an MOSFET (metal oxide semiconductor field effect transistor) and a flyback transformer to realize the purpose of getting electricity from a vehicle high-voltage power battery pack, omits a transformer auxiliary power supply winding for supplying power to a power management chip, gets electricity from a battery high-voltage input end through a primary winding of the flyback transformer and a high-voltage MOSFET main switch in a power supply loop of the power management chip, has high integration level and low cost of a power supply structure, reduces the occupied space, optimizes an external circuit and works more stably and reliably.

The purpose of the utility model can be realized by the following technical scheme:

a standby power supply of a vehicle-mounted motor controller comprises a high-voltage input port, a low-voltage output port, a flyback transformer, an absorption circuit, a power supply starting circuit, a power supply management chip, a high-voltage MOSFET main switch, a gate pole protection circuit and a rectification circuit, wherein the high-voltage input port is connected to a vehicle-mounted power battery pack, the anode of the input end of the flyback transformer is connected to the anode of the high-voltage input port through the absorption circuit, the cathode of the input end of the flyback transformer is connected to the drain electrode of the high-voltage MOSFET main switch, the gate pole of the high-voltage MOSFET main switch is connected to the anode of the high-voltage input port through the power supply starting circuit, the source electrode of the high-voltage MOSFET main switch is connected to the power supply input anode of the power supply management chip, the power supply input cathode of the power supply management chip is connected to the cathode of the high-voltage input port, the gate pole protection circuit is arranged between the gate pole and the source electrode of the high-voltage MOSFET main switch, and the output end of the flyback transformer is connected to the low-voltage output port through the rectification circuit, and the anode of the low-voltage output port is connected to the signal input end of the power management chip.

Further, the absorption circuit is an RCD absorption loop.

Furthermore, the standby power supply also comprises an input capacitor, one end of the input capacitor is connected with the power supply starting circuit, and the other end of the input capacitor is connected with the negative electrode of the high-voltage input port.

Furthermore, the power supply starting circuit comprises a first resistor and a second resistor, one end of the first resistor is connected with the anode of the high-voltage input port, the other end of the first resistor is connected with one end of the second resistor and the input capacitor, and the other end of the second resistor is connected with the grid electrode of the high-voltage MOSFET main switch.

Furthermore, the power management chip is a power management chip with a built-in high-voltage MOSFET, the standby power supply further comprises a TVS clamping protection circuit, one end of the TVS clamping protection circuit is connected to the grid electrode of the main switch of the high-voltage MOSFET, and the other end of the TVS clamping protection circuit is connected to the negative electrode of the high-voltage input port.

Further, the rectifier circuit comprises a rectifier diode and a diode absorption module, the anode of the rectifier diode is connected to one pole of the output end of the flyback transformer, the other end of the rectifier diode is connected to the anode of the low-voltage output port, the other pole of the output end of the flyback transformer is connected to the cathode of the low-voltage output port, and the diode absorption module is connected with the rectifier diode in parallel.

Further, the standby power supply also comprises a work indicating circuit, and the work indicating circuit is connected with the low-voltage output port.

Further, the standby power supply also comprises an output filter circuit, and the output filter circuit is connected with the low-voltage output port.

Further, the standby power supply further comprises an input filter circuit, and the input filter circuit is connected with the high-voltage input port.

Furthermore, a fuse is arranged between the high-voltage input port and the power supply starting circuit.

Compared with the prior art, the utility model has the following beneficial effects:

1) the power supply circuit of the power management chip is characterized in that the power supply circuit comprises a battery, a high-voltage power battery pack, a flyback transformer, a power supply management chip, a power supply circuit, a power supply control circuit and a power supply control circuit, wherein the power supply control circuit comprises a power supply management chip, a power supply control circuit, a flyback transformer primary winding, a high-voltage MOSFET main switch and a power supply control circuit.

2) And the RCD absorption loop is adopted, so that the reliability is higher.

3) The power supply starting circuit adopts the design of two series resistors, can realize the charging of an input capacitor and the conducting driving of a high-voltage MOSFET main switch grid electrode, and has low cost.

4) The rectifier diode, the diode absorption module and the rectifier circuit are designed, so that the number of devices is small, and the cost is low.

5) The work indication circuit can provide man-machine feedback, thereby improving use experience and safety.

6) The TVS clamping protection circuit can clamp a voltage spike generated in the turn-off process of the MOSFET in the power management chip, so that the MOSFET in the power management chip is prevented from being broken down.

Drawings

FIG. 1 is a schematic structural diagram of an embodiment of the present invention;

FIG. 2 shows power operation test waveforms according to an embodiment of the present invention.

Detailed Description

The utility model is described in detail below with reference to the figures and specific embodiments. The present embodiment is implemented on the premise of the technical solution of the present invention, and a detailed implementation manner and a specific operation process are given, but the scope of the present invention is not limited to the following embodiments.

A standby power supply of a vehicle-mounted motor controller is disclosed, as shown in figure 1, and comprises a high-voltage input port and a low-voltage output port, a flyback transformer TR1 and an absorption circuit, a power supply starting circuit, a power supply management chip U1, a high-voltage MOSFET main switch Q1 and a gate protection circuit, and a rectification circuit, wherein the high-voltage input port, namely DC + and DC-in figure 1, is a voltage input port of a BMS battery and is connected to a vehicle-mounted power battery pack, the positive pole of the input end of the flyback transformer TR1 is connected to the positive pole of the high-voltage input port through the absorption circuit, the negative pole is connected to the drain of the high-voltage MOSFET main switch Q1, the grid of the high-voltage MOSFET main switch Q1 is connected to the positive pole of the high-voltage input port through the power supply starting circuit, the source is connected to the power supply input positive pole of the power supply management chip U1, the power supply input negative pole of the power supply management chip U1 is connected to the negative pole of the high-voltage input port, the gate protection circuit is arranged between the grid and the source of the high-voltage MOSFET main switch Q1, the output end of the flyback transformer TR1 is connected with a low-voltage output port through a rectifying circuit, the anode of the low-voltage output port is connected to the signal input end of the power management chip U1, and the output voltage is fed back to the power management chip U1 to achieve precision adjustment of the output voltage.

The power supply management circuit has the advantages that the power supply from the vehicle high-voltage power battery pack is realized by adopting the mode of one MOSFET and the flyback transformer TR1, the transformer auxiliary power supply winding for supplying power to the power management chip U1 is omitted, the power supply management chip U1 supplies power to the power loop from the battery high-voltage input end through the primary winding of the flyback transformer TR1 and the high-voltage MOSFET main switch Q1, the power supply structure is high in integration level and low in cost, the occupied space is reduced, the external circuit is optimized, and the circuit works more stably and reliably.

In this embodiment, the absorption circuit is an RCD absorption loop, which has a better absorption effect and improves stability, and is composed of a resistor R2, a capacitor C3 and a diode D2, and the loop is used to reduce the leakage inductance of the flyback transformer TR1 and the turn-off voltage spike generated by the resonance of the junction capacitor of the high-voltage MOSFET main switch Q1, thereby preventing the overvoltage damage of the device. The specific working path is that the high di/dt of the high-voltage MOSFET main switch Q1 resonates at the leakage inductance of the transformer and the junction capacitance of the MOSFET during the rapid turn-off process to generate a high voltage spike, the voltage spike is absorbed by the C3 capacitor through the D2, and simultaneously the energy of the C3 capacitor is released by the discharge resistor R2. D2 requires an ultrafast recovery diode of 1000V type to prevent reverse breakdown by high voltage. In other embodiments, the absorption circuit may also take the form of an RC absorption circuit or the like.

In this embodiment, the standby power supply further includes an input capacitor C2, one end of the input capacitor C2 is connected to the power supply starting circuit, the other end of the input capacitor C2 is connected to the negative electrode of the high-voltage input port, the power supply starting circuit includes a first resistor R1 and a second resistor R5, one end of the first resistor R1 is connected to the positive electrode of the high-voltage input port, the other end of the first resistor R1 is connected to one end of the second resistor R5 and the input capacitor C2, and the other end of the second resistor R5 is connected to the gate of the high-voltage MOSFET main switch Q1. The power supply starting circuit adopts the design of two series resistors, can realize the charging of the input capacitor C2 and the conducting driving of the high-voltage MOSFET main switch grid, and has low cost.

In some embodiments, the power management chip U1 is a power management chip U1 with a built-in high voltage MOSFET, and the standby power supply further includes a TVS clamp protection circuit, one end of the TVS clamp protection circuit is connected to the gate of the high voltage MOSFET main switch Q1, and the other end of the TVS clamp protection circuit is connected to the cathode of the high voltage input port, and the TVS clamp protection circuit can clamp a voltage spike generated during the turn-off process of the MOSFET in the power management chip U1, so as to prevent the MOSFET in the power management chip U1 from being broken down. In this embodiment, the TVS clamp protection circuit employs a voltage regulator tube Z1.

In the embodiment, the gate protection circuit adopts a voltage regulator Z2, and a voltage regulator Z2 connected to the grid and the source of the Q1 can clamp the gate voltage of the Q1 and protect the Q1 transistor from gate overvoltage breakdown.

In some embodiments, the rectifier circuit includes a rectifier diode D3 and a diode absorption module, an anode of the rectifier diode D3 is connected to one pole of the output terminal of the flyback transformer TR1, the other end of the rectifier diode D3 is connected to an anode of the low-voltage output port, the other pole of the output terminal of the flyback transformer TR1 is connected to a cathode of the low-voltage output port, and the diode absorption module is connected in parallel with the rectifier diode D3. In this embodiment, the diode absorption module is formed by connecting a capacitor C4 and a resistor R3 in series.

In this embodiment, the low-voltage output port is connected to a controller for hardware active short-circuit protection, so that the function of hardware active short-circuit protection can be still started when a vehicle carrying the permanent magnet synchronous motor is in a stalled state. Of course, in other embodiments, other low-voltage power supply modules may be powered.

In some embodiments, the standby power supply further includes an operation indication circuit, the operation indication circuit is connected to the low voltage output port, in this embodiment, the operation indication circuit is a light emitting diode LED1, and the resistor R4 is connected in parallel to the light emitting diode LED 1.

In some embodiments, the backup power supply further comprises an output filter circuit coupled to the low voltage output port, and the backup power supply further comprises an input filter circuit coupled to the high voltage input port. A fuse FU1 is arranged between the high-voltage input port and the power supply starting circuit, when an output power supply loop is short-circuited, a large current is generated through an FU1 loop on the primary side of a flyback transformer TR1, the FU1 can be burnt due to overheating, the power supply loop is disconnected and stops working, and the purpose of protecting a rear-stage component is achieved.

All the electronic components meet the requirements of vehicle-level applications, namely, the components passing AEC-Q certification, the flyback transformer TR1 needs to meet the requirements of vehicle-level applications, including temperature resistance, electrical insulation, vibration and the like, and the leakage inductance of the flyback transformer is designed to be less than 3%.

The standby power supply works in a DCM mode, and a closed-loop control system of the flyback power supply is formed by the power supply loop compensation, the current sampling, the error calculation, the PID control module and the PWM control and drive unit in the power supply chip based on the output voltage sampling. The voltage range of the BMS battery input port is 200V-900V, and the high-voltage input end is connected with a filter capacitor in parallel to filter high-frequency interference signals of the input port. Fuse resistor FU1 is connected between DC + and pin 1 of transformer TR 1.

The working principle of the embodiment is as follows:

1. the primary side circuit of the transformer of the standby power supply is powered by BMS battery voltage DC + and DC-, a C2 capacitor is charged through a first resistor R1, the grid electrode of a Q1 is driven to be conducted through a second resistor R5, and a voltage regulator tube Z2 connected to the grid electrode of the Q1 and a source stage can clamp the gate voltage of the Q1 to protect the Q1 tube from gate overvoltage breakdown.

2. When the Q1 is conducted, the battery voltage DC + supplies power to a power supply loop inside the U1 chip through the FU1, a pin 1 and a pin 4 of a primary winding of the transformer, and a drain stage and a source stage of the Q1, and when the power supply voltage reaches a threshold voltage for starting the U1 chip, the U1 chip works to generate PWM pulse inside the U1 chip to drive a MOSFET inside the U1 chip to work.

3. The TVS tube Z1 can clamp the voltage spike generated in the process of turning off the MOSFET in the U1, and the specific working path is that the high di/dt of the U1 built-in MOSFET in the process of fast turning off generates a high voltage spike in the parasitic inductance of a loop, and the voltage spike is clamped by the TVS tube Z1 through Z2 and R5, so that the MOSFET is prevented from being damaged by high voltage breakdown.

4. When the power supply normally operates, the test waveforms shown in fig. 2 are, from top to bottom, a Vgs voltage waveform of Q1, a Vds voltage waveform of Q1, and a Vds voltage waveform of U1.

5. The RCD absorption loop is composed of D2, R2 and C3, and is used for reducing leakage inductance of a transformer and off-voltage spike generated by junction capacitance resonance of a MOSFET (metal oxide semiconductor field effect transistor), and preventing overvoltage damage of devices. The specific working path is that the high di/dt of the Q1 in the fast turn-off process resonates at the transformer leakage inductance and the MOSFET junction capacitance to generate a high voltage spike, which is absorbed by the C3 capacitance through the D2, and the energy of the C3 capacitance is released by the discharge resistor R2. D2 requires an ultrafast recovery diode of 1000V type to prevent reverse breakdown by high voltage.

6. The secondary side circuit of the flyback transformer TR1 is composed of a pin 8 of the flyback transformer through D3, C5 and a pin 5 of the transformer to form a rectifying loop on the secondary side of the flyback transformer TR1 to output direct-current voltage. The absorption loop formed by the R3 and the C4 is used for absorbing voltage spikes generated by reverse recovery at the turn-off time of the D3.

7. The +15V power supply voltage output by the secondary side is firstly displayed and fed back by the LEDs 1 and the R4, then the +15V power supply voltage sampling and voltage feedback module feeds back the sampled voltage to the U1 power supply chip, and a voltage closed-loop control loop is formed by the +15V power supply voltage sampling and voltage feedback module and the power supply loop compensation module outside the U1, so that the stable +15V voltage is ensured to be output.

Claims

1. A standby power supply of a vehicle-mounted motor controller is characterized by comprising a high-voltage input port and a low-voltage output port, a flyback transformer, an absorption circuit, a power supply starting circuit, a power supply management chip, a high-voltage MOSFET main switch, a gate pole protection circuit and a rectification circuit, wherein the high-voltage input port is connected to a vehicle-mounted power battery pack, the anode of the input end of the flyback transformer is connected to the anode of the high-voltage input port through the absorption circuit, the cathode of the input end of the flyback transformer is connected to the drain electrode of the high-voltage MOSFET main switch, the grid electrode of the high-voltage MOSFET main switch is connected to the anode of the high-voltage input port through the power supply starting circuit, the source electrode of the high-voltage MOSFET main switch is connected to the power supply input anode of the power supply management chip, the power supply input cathode of the power supply management chip is connected to the cathode of the high-voltage input port, the gate pole protection circuit is arranged between the grid electrode and the source electrode of the high-voltage MOSFET main switch, the output end of the flyback transformer is connected to the low-voltage output port through the rectification circuit, and the anode of the low-voltage output port is connected to the signal input end of the power management chip.

2. The backup power supply for a vehicle motor controller according to claim 1, wherein said absorption circuit is an RCD absorption loop.

3. The vehicle-mounted motor controller standby power supply according to claim 1, wherein the standby power supply further comprises an input capacitor, one end of the input capacitor is connected with the power supply starting circuit, and the other end of the input capacitor is connected with the negative electrode of the high-voltage input port.

4. The vehicle-mounted motor controller standby power supply as claimed in claim 3, wherein the power supply starting circuit comprises a first resistor and a second resistor, one end of the first resistor is connected with the anode of the high-voltage input port, the other end of the first resistor is connected with one end of the second resistor and the input capacitor, and the other end of the second resistor is connected with the grid electrode of the high-voltage MOSFET main switch.

5. The backup power supply of claim 1, wherein the power management chip is a built-in high voltage MOSFET power management chip, and the backup power supply further comprises a TVS clamp protection circuit, one end of the TVS clamp protection circuit is connected to the gate of the main switch of the high voltage MOSFET, and the other end of the TVS clamp protection circuit is connected to the negative electrode of the high voltage input port.

6. The backup power supply of the vehicle-mounted motor controller according to claim 1, wherein the rectifying circuit includes a rectifying diode and a diode absorption module, an anode of the rectifying diode is connected to one pole of the output end of the flyback transformer, the other pole of the output end of the flyback transformer is connected to an anode of the low voltage output port, the other pole of the output end of the flyback transformer is connected to a cathode of the low voltage output port, and the diode absorption module is connected in parallel with the rectifying diode.

7. The vehicle-mounted motor controller backup power supply according to claim 1, characterized in that the backup power supply further comprises an operation indication circuit, and the operation indication circuit is connected with the low voltage output port.

8. The vehicle-mounted motor controller backup power supply according to claim 1, characterized in that the backup power supply further comprises an output filter circuit, and the output filter circuit is connected with the low-voltage output port.

9. The vehicle motor controller backup power supply of claim 1, further comprising an input filter circuit, the input filter circuit being connected to the high voltage input port.

10. The backup power supply for the vehicle-mounted motor controller according to claim 1, wherein a fuse is provided between the high voltage input port and the power supply starting circuit.