Braking resistor system for absorbing energy on new energy vehicle

Abstract

The utility model discloses a new energy vehicle energy absorbing brake resistance system, including resistance controller and brake resistance box, wherein resistance controller includes IGBT, IGBT control circuit, the IGBT is electrically connected with IGBT control circuit, brake resistance box includes brake resistor and heat dissipation fan, brake resistor is electrically connected with IGBT, the heat dissipation fan is electrically connected with the IGBT control circuit, the heat dissipation fan is electrically connected with the IGBT control circuit, the heat dissipation fan is electrically connected with the IGBT control circuit, and the heat dissipation fan is electrically connected with the heat dissipation fan. The heat dissipation branch fan is arranged in the brake resistor box, and the heat dissipation branch fan is electrically connected with the IGBT control circuit; the IGBT control circuit comprises a PWM processing unit. The PWM processing unit is used for obtaining and processing a direct current PWM1 signal and then controlling start and stop of a cooling fan. And the driving unit is used for controlling the turn-off and turn-on of the IGBT after acquiring the PWM1 signal. Resistors in the whole high-voltage loop are used for absorbing excess energy, auxiliary braking of the motor can be carried out when the whole vehicle is in a full-power state, the problem that regenerative braking of the motor is interrupted can be solved, and the safety and the driving mileage of the whole vehicle can be improved.

Description

Technical Field

[0001] The utility model relates to the technical field of new energy vehicles, in particular to a braking resistor system for absorbing energy on a new energy vehicle. Background Technique

[0002] At present, the auxiliary braking of new energy electric vehicles mainly adopts electric regenerative braking, which has the following deficiencies:

[0003] 1. For the electric regenerative braking generated during long-term braking, when the battery is fully charged or the battery activity is weak in winter, the battery charging will be restricted, and the auxiliary braking force will be weakened or even interrupted, thus affecting the braking performance of the vehicle;

[0004] 2. Frequent feedback charging or overcharging has a certain impact on the battery life;

[0005] 3. Under specific conditions (when the battery SOC state of charge is relatively high), the auxiliary braking cannot meet some national standard experiments;

[0006] 4. New energy electric vehicles need to meet some requirements of GB12676 and EU R13 regulations:

[0007] For a fully loaded vehicle on a 7% downhill slope, the braking device shall not be used, and the vehicle can descend at a stable speed of 30 km / h. Summary of the Invention

[0008] The purpose of the utility model is to provide a braking resistor system for absorbing energy on a new energy vehicle to solve the problems put forward in the above background technique.

[0009] To achieve the above purpose, the utility model provides the following technical solution: A braking resistor system for absorbing energy on a new energy vehicle, including a resistor controller and a braking resistor box, the resistor controller and the braking resistor box are electrically connected, wherein the resistor controller includes an IGBT and an IGBT control circuit, the IGBT and the IGBT control circuit are electrically connected, the braking resistor box includes a braking resistor and a cooling fan, the braking resistor is electrically connected to the IGBT, the cooling fan is arranged inside the braking resistor box, and the cooling fan is electrically connected to the IGBT control circuit for dissipating heat from the braking resistor through the control of the IGBT control circuit; the IGBT control circuit includes:

[0010] A PWM processing unit, which is used to obtain the DC PWM1 signal, process it and control the start and stop of the cooling fan; and

[0011] A driving unit, which is used to obtain the PWM1 signal and control the turn-off and turn-on of the IGBT.

[0012] Further, the PWM processing unit includes an operational amplifier U1, resistors R31, R30, R17, R35, R33, and a capacitor C20. One end of the resistor R33 is connected to the resistor R31. The resistors R31 and R30 are connected in series and then connected to the positive input terminal of the operational amplifier U1. The resistors R35 and R17 are connected in series and then connected to the output terminal of the operational amplifier U1. One end of the capacitor C20 is connected to one end of the resistor R35.

[0013] Further, the PWM processing unit further includes a switching diode D10. The switching diode D10 is connected between the capacitor C20 and the resistor R35, and this switching diode D10 is used to control the voltage of the operational amplifier U1.

[0014] Further, the IGBT control circuit further includes a temperature sampling unit for obtaining a temperature sampling signal of the braking resistor. The temperature sampling unit includes an LC filter circuit, resistors R124, R157, R158, and an operational amplifier U13. One end of the resistor R124 is connected to the LC filter circuit. The resistors R158 and R157 are connected in series in sequence and then connected to the LC filter circuit.

[0015] Further, the LC filter circuit includes inductors L9, L10, capacitors C157, C149, and a resistor R126. The capacitors C157, C149, and the resistor R126 are connected in parallel and then one end is connected to the inductor L9, and the other end is connected to the inductor L10.

[0016] Further, the temperature sampling unit further includes a switching diode D11. The switching diode D11 is connected between the operational amplifier U13 and the resistor R158, and this switching diode D11 is used to control the voltage of the operational amplifier U13.

[0017] Further, the driving unit includes a driving optocoupler U2, capacitors C21, C22, C43, C27, C23, C24, C51, C47, C46, C26, C25, C49, C51, resistors R7, R4, R23, R25, R9, R14, R16, R33, a TVS (Transient Voltage Suppressor) bidirectional transient suppression diode D12, a zener diode D10, diodes D3, D4, D7, D8 and a push-pull circuit. One end of the resistor R7 is connected in series with the resistor R9 and then connected to the driving optocoupler U2, and the other end of the resistor R7 is connected to the driving optocoupler U2 after being connected to the serially connected C21 and C22 in sequence. One end of the resistor R4 is connected between R9 and the driving optocoupler U2. One end of the capacitor C43 is connected to R14, and the other end of C43 is connected to the driving optocoupler U2. The driving optocoupler U2 is connected between the capacitor C43 and R14. One end of the resistor R16 is connected to R14, and the other end is connected to the driving optocoupler U2. The capacitors C27, C23, C24 are connected in parallel and then connected to the driving optocoupler U2. The diodes D4 and D3 are connected in series in sequence and then connected to the resistor R14. The capacitor C51 and the resistor R23 are connected in parallel and then connected to the driving optocoupler U2. The capacitors C47, C26, D10 are connected in parallel and then connected to the parallel-connected capacitor C46 and capacitor C25. One end of the resistor R33 is connected to D10, and the other end is connected to C25. The capacitor C49, R25, D12 are connected in parallel and then connected to the diodes D7 and D8 respectively.

[0018] Further, the push-pull circuit includes transistors Q2, Q4, resistors R44, R46, R28. The emitter of the transistor Q2 is connected to the emitter of Q4. The bases of the transistors Q2 and Q4 are connected and then connected to the driving optocoupler U2 through the resistor R28. The collector of the transistor Q2 is connected between the capacitors C46 and C24. The collector of Q4 is connected between C47 and R23. The resistors R44 and R46 are connected in parallel and then connected to the emitters of the transistors Q2 and Q4 through the diode D7.

[0019] Further, the transistor Q2 is an NPN transistor, and the transistor Q4 is a PNP transistor.

[0020] Further, a CAN wire harness connection end, a communication wire harness connection end and a fan control wire harness connection end are provided on the IGBT control circuit. The CAN wire harness connection end and the communication wire harness connection end are electrically connected to the whole vehicle, and the fan control wire harness connection end is electrically connected to the cooling fan.

[0021] Compared with the prior art, the beneficial effects of the present utility model are:

[0022] 1. The vehicle control unit (VCU) distributes the braking power according to the braking demand and the state of charge, and sends the power that needs to be consumed by the braking resistor system (BRS) through the vehicle CAN bus. The braking resistor controller (BRC) receives the instruction, adjusts the current flowing through the resistor box through PWM, performs closed-loop control, and responds in real time. The braking resistor (BR) absorbs the braking energy and converts it into heat under the control of the controller, and dissipates the heat through air cooling. The resistor in the entire high-voltage circuit absorbs the excess energy, realizing the absorption of the excess energy generated during the vehicle braking process. When the vehicle is in a fully charged state, motor-assisted braking can also be performed. After the resistor in the high-voltage circuit absorbs the excess energy, the problem of the interruption of the motor regenerative braking will be solved, and the continuity of the assisted braking can be ensured, which is beneficial to improving the safety and driving range of the vehicle;

[0023] 2. A cooling fan is used as the cooling system to accelerate the cooling of the braking resistor;

[0024] 3. The braking resistor system circuit uses IGBT as a switch, which has higher voltage and current handling capabilities. A fuse is added to the circuit for circuit protection, which helps to protect the braking resistor, the controller, and the battery pack. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the overall structure in the present utility model;

[0026] Figure 2 It is a schematic diagram of the PWM processing unit circuit in the present utility model;

[0027] Figure 3 It is a schematic diagram of the temperature sampling unit circuit in the present utility model;

[0028] Figure 4 It is a schematic diagram of the drive unit circuit in the present utility model. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0029] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.

[0030] Please refer to Figures 1-4, the present utility model provides a technical solution: a braking resistor system for absorbing energy on a new energy vehicle, including a resistor controller 1 and a braking resistor box 2. The positive and negative battery terminals of the resistor controller 1 are respectively connected to the positive and negative terminals of the high-voltage power distribution at the rear end of the vehicle's MCU. The BR+ and BR- of the resistor controller 1 are respectively connected to the BR+ and BR- of the braking resistor box 2. Among them, the resistor controller 1 includes an IGBT, an IGBT control circuit, a thin-film capacitor, and a fuse. The IGBT and the IGBT control circuit are electrically connected, and the IGBT control circuit is connected to the fuse after being connected in parallel with the thin-film capacitor. The braking resistor box 2 includes a braking resistor 201 and a cooling fan 202. The braking resistor 201 is electrically connected to the IGBT. The cooling fan 202 is arranged inside the braking resistor box, and the cooling fan 202 is electrically connected to the IGBT control circuit for dissipating heat from the braking resistor 201 through the control of the IGBT control circuit. A CAN wire harness connection terminal 101, a communication wire harness connection terminal 102, and a fan control wire harness connection terminal 103 are arranged on the IGBT control circuit. The CAN wire harness connection terminal 101 and the communication wire harness connection terminal 102 (transmitting ±24V, CANH and CANL, ON gear signal) are respectively connected to the vehicle's OBD and the vehicle's low-voltage wire harness. The fan control wire harness connection terminal 103 (transmitting fault feedback, PT100 temperature detection, PWM signal) is connected to the fan wire harness connector. The fan wire harness connector is located inside the resistor controller (not shown in the figure), and the fan wire harness connector is electrically connected to the cooling fan 202. The low-voltage wire of the resistor box includes a fan control signal and a power supply wire, which are respectively connected to the resistor controller and the vehicle's low-voltage wire harness.

[0031] The IGBT control circuit includes a PWM processing unit, a driving unit, and a temperature sampling unit. The PWM processing unit is used to obtain the DC PWM1 signal, process it, and control the start and stop of the cooling fan. The driving unit is used to control the turn-off and turn-on of the IGBT after obtaining the PWM1 signal. The temperature sampling unit is used to obtain the temperature sampling signal of the braking resistor and upload it.

[0032] The PWM processing unit includes an operational amplifier U1, resistors R31, R30, R17, R35, R33, a capacitor C20, and a switching diode D10. One end of the resistor R33 is connected to the resistor R31. The resistors R31 and R30 are connected in series and then connected to the positive input terminal of the operational amplifier U1. The resistors R35 and R17 are connected in series and then connected to the output terminal of the operational amplifier U1. One end of the capacitor C20 is connected to one end of the resistor R35. The switching diode D10 is connected between the capacitor C20 and the resistor R35, and this switching diode D10 is used to control the voltage of the operational amplifier U1.

[0033] The PWM processing unit is a non-inverting amplifier circuit of an operational amplifier U1. The non-inverting operational amplifier circuit will amplify the signal value of pin 1 of U1 by (1 + R8 / R7); the resistors R31, R30, R17, and R35 all play a role in current limiting to protect the circuit, and the resistor R33 plays a pulling-down role; the switching diode D10 plays a role in clamping the circuit, protecting the voltage of PWM1 between -Vdf and (24V + Vdf), where Vdf is the forward voltage drop of the switching diode D11; the capacitor C20 plays a filtering role, filtering out the low-frequency AC signal of PWM1 and transmitting the DC PWM1 signal to the DSP to cooperate with the software to start the braking resistor cooling fan to cool the braking resistor.

[0034] The temperature sampling unit includes an LC filter circuit, resistors R124, R157, R158, an operational amplifier U13, and a switching diode D11. One end of the resistor R124 is connected to the LC filter circuit, and the resistors R158 and R157 are connected in series and then connected to the LC filter circuit; the LC filter circuit includes inductors L9, L10, capacitors C157, C149, and a resistor R126. The capacitors C157, C149, and the resistor R126 are connected in parallel, and one end is connected to the inductor L9 and the other end is connected to the inductor L10. The switching diode D11 is connected between the operational amplifier U13 and the resistor R158, and this switching diode D11 is used to control the voltage of the operational amplifier U13.

[0035] The inductors L9, L10, capacitors C157, C149, and the resistor R126 are combined to form an LC filter circuit. The inductor L9 is connected in series with the resistor R126. The inductor L9 itself provides a high resistance for the AC signal and allows the DC signal to flow through the load resistor. The load resistor R126 is connected to the parallel capacitors at both ends to filter out the AC signal flowing through the inductor L9. Through this LC filter combination, rectification can be obtained and smooth direct current can be provided. The resistor R124 is connected to the 5V power supply to form a 5V power supply pull-up; the operational amplifier U13 acts as a follower. The operational amplifier U13 has the characteristics of infinite input impedance and infinite small output impedance, playing a role in signal isolation in this circuit to ensure that the ADC_NTC1 temperature sampling signal output by the operational amplifier U13 is transmitted to the DSP without being affected by the change of the DSP internal resistance; the switching diode D11 plays a role in clamping the circuit, protecting the voltage of pin 10 of U13 between -Vdf and (3.3V + Vdf), where Vdf is the forward voltage drop of the switching diode D11.

[0036] The driving unit includes a driving optocoupler U2, capacitors C21, C22, C43, C27, C23, C24, C51, C47, C46, C26, C25, C49, C51, resistors R7, R4, R23, R25, R9, R14, R16, R33, a TVS (bidirectional transient voltage suppressor) diode D12, a zener diode D10, diodes D3, D4, D7, D8 and a push-pull circuit. One end of the resistor R7 is connected in series with the resistor R9 and then connected to the driving optocoupler U2, and the other end of the resistor R7 is connected to the driving optocoupler U2 after being connected to the serially connected C21 and C22 in sequence. One end of the resistor R4 is connected between R9 and the driving optocoupler U2. One end of the capacitor C43 is connected to R14, and the other end of C43 is connected to the driving optocoupler U2. The driving optocoupler U2 is connected between the capacitor C43 and R14. One end of the resistor R16 is connected to R14, and the other end is connected to the driving optocoupler U2. The capacitors C27, C23, C24 are connected in parallel and then connected to the driving optocoupler U2. The diodes D4 and D3 are connected in series in sequence and then connected to the resistor R14. The capacitor C51 and the resistor R23 are connected in parallel and then connected to the driving optocoupler U2. The capacitors C47, C26, D10 are connected in parallel and then connected to the parallel-connected capacitor C46 and capacitor C25. One end of the resistor R33 is connected to D10, and the other end is connected to C25. The capacitors C49, R25, D12 are connected in parallel and then connected to the diodes D7, D8 respectively.

[0037] The push-pull circuit includes transistors Q2, Q4, resistors R44, R46, R28. The emitter of the transistor Q2 is connected to the emitter of Q4. The bases of the transistors Q2 and Q4 are connected and then connected to the driving optocoupler U2 through the resistor R28. The collector of the transistor Q2 is connected between the capacitor C46 and C24. The collector of Q4 is connected between C47 and R23. The resistors R44 and R46 are connected in parallel and then connected to the emitters of the transistors Q2 and Q4 through the diode D7. The transistor Q2 is an NPN transistor, and the transistor Q4 is a PNP transistor.

[0038] VEE1 and NC in U2 are connected to the common ground COM; VCC1 is connected to the 13V power supply to supply power to the chip; UVLO is the under-voltage lockout feedback for VCC2; FAULT is the over-current feedback; AN is the input anode; CA is the input cathode; VEE2 is the negative power supply; LED2+ is for chip manufacturer's test, and the circuit diagram is left floating; Desat is the over-current sensing; VE is the igbt light source reference; VCC2 is the positive power supply; VO is the IGBT gate drive signal; VEE2 is the negative power supply; R7 is used for 5V pull-up, and R4, R23, R25 are used for pull-down. Resistors such as R9, R14, R16, R26, R44, R46 play a shunting role; The TVS bidirectional transient suppression diode D12 is connected in parallel in the circuit to play a protection role. When the circuit is working normally, the TVS is in the cut-off state (high impedance state) and does not affect the normal operation of the circuit. When an abnormal overvoltage occurs in the circuit and reaches the TVS (avalanche) breakdown voltage, the TVS quickly changes from the high-resistance state to the low-resistance state, discharging the instantaneous overcurrent caused by the abnormal overvoltage to the ground, and at the same time clamping the abnormal overvoltage at a lower level, thereby protecting the subsequent circuit from damage by the abnormal overvoltage. When the abnormal overvoltage disappears, the resistance value of the TVS returns to the high-impedance state again. The zener diode D10 protects the circuit from being broken down by high current and stabilizes the circuit voltage; D3, D4, D7, D8 are diodes with the functions of one-way conduction and reverse cut-off. If the voltage at the back end of the circuit is abnormal, the diodes play a protection role to prevent voltage backflow and burn out the driving optocoupler U2;

[0039] R44, R46, R28, Q2, and Q4 are combined into a push-pull circuit. When the PU+ and PU- voltage signals of the PWM wave signal are used as the anode and cathode of the driving optocoupler, and the working power supply of the driving optocoupler is normally input and the grounding is normal, the driving optocoupler will work normally. The driving optocoupler VO serves as the IGBT gate drive signal. When VO sends a high level, Q2 in the push-pull circuit conducts and Q4 cuts off. The high-level input circuit of UL+ passes through the push-pull circuit, and a high-level voltage difference is output between U_L_G and U_L_E, and the IGBT closes. When VO sends a low level, Q2 in the push-pull circuit cuts off and Q4 conducts. The low-level input circuit of UL- passes through the push-pull circuit, and a low-level voltage difference is output between U_L_G and U_L_E, and the IGBT disconnects.

[0040] This drive circuit will control the turn-off and turn-on of the IGBT, thereby realizing the disconnection and connection of the braking resistor system loop. The braking resistor can play a role in consuming the excess feedback of new energy vehicles in the loop.

[0041] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A braking resistor system for absorbing energy in a new energy vehicle, characterized in that, It includes a resistance controller (1) and a braking resistor box (2), the resistance controller (1) and the braking resistor box (2) are electrically connected. Among them, the resistance controller (1) includes an IGBT and an IGBT control circuit, the IGBT and the IGBT control circuit are electrically connected. The braking resistor box (2) includes a braking resistor (201) and a cooling fan (202), the braking resistor (201) is electrically connected to the IGBT, the cooling fan (202) is arranged inside the braking resistor box, and the cooling fan (202) is electrically connected to the IGBT control circuit for dissipating heat from the braking resistor (201) through the control of the IGBT control circuit; The IGBT control circuit includes: A PWM processing unit, which is used to obtain the DC PWM1 signal, process it and control the start and stop of the cooling fan; and A driving unit, which is used to control the turn-off and turn-on of the IGBT after obtaining the PWM1 signal.

2. The braking resistor system for absorbing energy on a new energy vehicle according to claim 1, wherein: The PWM processing unit includes an operational amplifier U1, resistors R31, R30, R17, R35, R33, and a capacitor C20. One end of the resistor R33 is connected to the resistor R31, the resistors R31 and R30 are connected in series and then connected to the positive input terminal of the operational amplifier U1, the resistors R35 and R17 are connected in series and then connected to the output terminal of the operational amplifier U1, and one end of the capacitor C20 is connected to one end of the resistor R35.

3. The braking resistor system for absorbing energy on a new energy vehicle according to claim 2, wherein: The PWM processing unit further includes a switching diode D10, the switching diode D10 is connected between the capacitor C20 and the resistor R35, and this switching diode D10 is used to control the voltage of the operational amplifier U1.

4. A braking resistor system for absorbing energy on a new energy vehicle according to claim 1, characterized in that: The IGBT control circuit further includes a temperature sampling unit for obtaining the temperature sampling signal of the braking resistor. The temperature sampling unit includes an LC filter circuit, resistors R124, R157, R158, and an operational amplifier U13. One end of the resistor R124 is connected to the LC filter circuit, and the resistors R158 and R157 are connected in series in sequence and then connected to the LC filter circuit.

5. A braking resistor system for absorbing energy on a new energy vehicle according to claim 4, characterized in that: The LC filter circuit includes inductors L9, L10, capacitors C157, C149, and a resistor R126. The capacitors C157, C149, and the resistor R126 are connected in parallel and then one end is connected to the inductor L9 and the other end is connected to the inductor L10.

6. The braking resistor system for absorbing energy on a new energy vehicle according to claim 4, wherein: The temperature sampling unit further includes a switching diode D11, the switching diode D11 is connected between the operational amplifier U13 and the resistor R158, and this switching diode D11 is used to control the voltage of the operational amplifier U13.

7. A braking resistor system for absorbing energy on a new energy vehicle according to claim 1, characterized in that: The driving unit includes a driving optocoupler U2, capacitors C21, C22, C43, C27, C23, C24, C51, C47, C46, C26, C25, C49, C51, resistors R7, R4, R23, R25, R9, R14, R16, R33, a TVS bidirectional transient suppression diode D12, a voltage regulator diode D10, diodes D3, D4, D7, D8 and a push-pull circuit. One end of the resistor R7 is connected in series with the resistor R9 and then connected to the driving optocoupler U2. The other end of the resistor R7 is connected to the driving optocoupler U2 after being connected to the series-connected C21 and C22 in sequence. One end of the resistor R4 is connected between R9 and the driving optocoupler U2. One end of the capacitor C43 is connected to R14, and the other end of C43 is connected to the driving optocoupler U2. The driving optocoupler U2 is connected between the capacitor C43 and R14. One end of the resistor R16 is connected to R14, and the other end is connected to the driving optocoupler U2. The capacitors C27, C23, C24 are connected in parallel and then connected to the driving optocoupler U2. The diodes D4 and D3 are connected in series in sequence and then connected to the resistor R14. The capacitor C51 and the resistor R23 are connected in parallel and then connected to the driving optocoupler U2. The capacitors C47, C26, D10 are connected in parallel and then connected to the parallel-connected capacitor C46 and capacitor C25. One end of the resistor R33 is connected to D10, and the other end is connected to C25. The capacitors C49, R25, D12 are connected in parallel and then connected to the diodes D7 and D8 respectively.

8. A braking resistor system for absorbing energy on a new energy vehicle according to claim 7, characterized in that: The push-pull circuit includes transistors Q2, Q4, resistors R44, R46, R28. The emitter of the transistor Q2 is connected to the emitter of Q4. The bases of the transistors Q2 and Q4 are connected and then connected to the driving optocoupler U2 through the resistor R28. The collector of the transistor Q2 is connected between the capacitors C46 and C24. The collector of Q4 is connected between C47 and R23. The resistors R44 and R46 are connected in parallel and then connected to the emitters of the transistors Q2 and Q4 through the diode D7.

9. A braking resistor system for absorbing energy on a new energy vehicle according to claim 8, characterized in that: The transistor Q2 is an NPN transistor, and the transistor Q4 is a PNP transistor.

10. A braking resistor system for absorbing energy on a new energy vehicle according to claim 1, characterized in that: The IGBT control circuit is provided with a CAN wire harness connection end (101), a communication wire harness connection end (102) and a fan control wire harness connection end (103). The CAN wire harness connection end (101) and the communication wire harness connection end (102) are electrically connected to the whole vehicle. The fan control wire harness connection end (103) is electrically connected to the cooling fan (202).

Images