IGBT (Insulated Gate Bipolar Translator) driving power supply circuit suitable for high-voltage heater of new energy vehicle

Abstract

The utility model discloses an IGBT driving power supply circuit suitable for a high-voltage heater of a new energy vehicle. The IGBT driving power supply circuit comprises a flyback power supply chip and an MOS tube. A pin EN of the flyback power supply chip is connected with an input power supply, and a pin GATE of the flyback power supply chip is connected with a G pole of the MOS tube; the D pole of the MOS tube is connected with the high-frequency transformer; the high-frequency transformer is provided with two secondary windings, the secondary winding M1 is connected with a diode D1 and a capacitor C1, and the secondary winding M2 is connected with a diode D2 and a capacitor C2; the high-frequency transformer is connected in parallel with an absorption loop and a protection circuit, the absorption loop comprises a capacitor C3 and a resistor R4, and the protection circuit comprises a diode D3 and a diode D4 which are reversely connected in series. According to the utility model, the circuit structure is optimized, the absorption loop and the protection circuit are added on the high-frequency transformer, peak absorption is realized, and the circuit safety is ensured, so that a flyback power supply chip of a power supply can be reduced, and the cost of the driving circuit can be further reduced.

Description

Technical Field

[0001] This utility model relates to a heating circuit unit for new energy vehicles, specifically to an IGBT drive power supply circuit suitable for high-voltage heaters in new energy vehicles. Background Technology

[0002] In new energy vehicles, the high-voltage heater is an electrically heated device whose main function is to provide heat to the battery, enabling it to operate normally in low-temperature environments and reducing energy loss. It also provides heat to the air conditioning system, defrosting and defogging system, and seats, ensuring normal vehicle operation and maintaining a comfortable temperature inside the cabin. The high-voltage heater generates heat by driving an electric heating film through IGBT units. The IGBT units control the on / off state between the heating film and the high-voltage electricity. For safety, two IGBT units are required: one connected to the negative terminal of the power supply, and the other connected to the positive terminal.

[0003] In the existing technology, the operating voltage of the electric heating film is generally high, reaching 300V to 500V; the control signals and communication ports of the IGBT unit require low voltage, generally 12V to 16V; an isolation power supply is needed between the high voltage and low voltage to meet the insulation requirements, so power conversion is required.

[0004] In existing technologies, to address the aforementioned issues, two isolated power supplies are typically designed to connect separately to the IGBT unit, requiring two independent transformer circuits. This necessitates the use of two transformers and two power supply chips, increasing costs. The reason for this approach in existing technologies is that using a single transformer to output two power supplies can easily lead to insufficient insulation withstand voltage. This can induce voltage spikes at the two ends of the transformer's primary winding. If these voltages are not limited, they can exceed the drain-source voltage of the chip, causing damage to related electronic components. Utility Model Content

[0005] The purpose of this invention is to provide an IGBT drive power supply circuit suitable for high-voltage heaters in new energy vehicles.

[0006] To achieve the above objectives, one embodiment of this utility model provides an IGBT drive power supply circuit suitable for high-voltage heaters in new energy vehicles, including a flyback power supply chip and a MOSFET; the EN pin of the flyback power supply chip is connected to the input power supply, and the GATE pin of the flyback power supply chip is connected to the gate of the MOSFET; the drain of the MOSFET is connected to a high-frequency transformer.

[0007] The high-frequency transformer is equipped with two secondary windings, namely secondary winding M1 and secondary winding M2. The output terminals of the two secondary windings are connected to two IGBT units respectively. One IGBT unit is connected to the positive terminal of the high-voltage heater power supply, and the other IGBT unit is connected to the negative terminal of the high-voltage heater power supply. A diode D1 and a capacitor C1 are connected to secondary winding M1, and a diode D2 and a capacitor C2 are connected to secondary winding M2.

[0008] The high-frequency transformer has an absorption circuit and a protection circuit connected in parallel. The absorption circuit includes a capacitor C3 and a resistor R4, and the protection circuit includes two diodes D3 and D4 connected in reverse series.

[0009] In the optimized solution of this utility model, the input power supply voltage of the flyback power chip is 4V to 60V, and a resistor R1 is provided between the input power supply and the flyback power chip.

[0010] In the optimized solution of this utility model, the RFB pin of the flyback power supply chip is connected between the drain of the MOSFET and the high-frequency transformer, and a resistor R2 is provided; the SENSE pin of the flyback power supply chip is connected to the source of the MOSFET and then grounded, and a resistor R3 is arranged on the grounding line.

[0011] In the optimized scheme of this utility model, the capacitance of capacitor C3 in the absorption circuit is 100pF, the rated voltage is 50V, and the resistance of resistor R4 is 200 ohms to 250 ohms; the capacitance of capacitors C1 and C2 on the secondary winding is 10μF, and the rated voltage is 25V.

[0012] In summary, this utility model has the following advantages:

[0013] This invention optimizes the circuit structure by adding an absorption circuit and a protection circuit to the high-frequency transformer, achieving peak absorption and ensuring circuit safety. As a result, it can reduce one power supply flyback chip, thereby reducing the cost of the drive circuit. Attached Figure Description

[0014] Figure 1 This is the circuit diagram of this utility model. Detailed Implementation

[0015] This invention provides an IGBT drive power supply circuit suitable for high-voltage heaters in new energy vehicles, including a flyback power supply chip U4 and a MOSFET. The flyback power supply chip can detect faults and control power output and line shutdown. The EN pin of the flyback power supply chip is connected to the input power supply, and the GATE pin is connected to the gate (G) of the MOSFET. The VIN pin of the flyback power supply chip is connected to the anode of diode D3 in the protection circuit and to capacitor C3 in the absorption circuit. The GND pin of the flyback power supply chip is grounded.

[0016] The flyback power supply chip U4 has its RFB pin connected between the drain (D) of the MOSFET and the high-frequency transformer, and a resistor R2 is installed thereon. The SENSE pin of the flyback power supply chip is connected to the source (S) of the MOSFET and then grounded, with a resistor R3 placed on the grounding line. Resistors R2 and R3 serve a protective function. The flyback power supply chip receives feedback voltage signals through the RFB and SENSE pins.

[0017] The drain (D) of the MOSFET is connected to a high-frequency transformer, which has two secondary windings, M1 and M2. The outputs of these two secondary windings are connected to two IGBT units, one connected to the positive terminal of the high-voltage heater power supply and the other to the negative terminal. A diode D1 and a capacitor C1 are connected to secondary winding M1, and a diode D2 and a capacitor C2 are connected to secondary winding M2. The diodes on the secondary windings provide regulation and protection, while the capacitors store energy and stabilize voltage.

[0018] The high-frequency transformer has an absorption circuit and a protection circuit connected in parallel. The absorption circuit includes a capacitor C3 and a resistor R4, and the protection circuit includes two diodes D3 and D4 connected in reverse series; among them, diode D3 is a Zener diode.

[0019] In the optimized embodiment of this utility model, the input power supply voltage of the flyback power chip is 4V to 60V, and a resistor R1 is provided between the input power supply and the flyback power chip.

[0020] In the optimized embodiment of this utility model, the capacitance of capacitor C3 in the absorption circuit is 100pF, the rated voltage is 50V, and the resistance of resistor R4 is 200 ohms to 250 ohms; the capacitance of capacitors C1 and C2 on the secondary winding is 10μF, and the rated voltage is 25V.

[0021] The circuit principle of this utility model is as follows:

[0022] The flyback power supply chip of this invention can periodically control the on / off state of the MOSFET, with a period generally ranging from 10kHz to 400kHz. Then, the MOSFET controls the energy storage and release of the high-frequency transformer to achieve isolated voltage conversion between input and output.

[0023] During the periodic turn-on and turn-off of a MOSFET, a voltage spike is induced at the drain of the MOSFET, which is also the N2 and N4 terminals of the primary winding of the high-frequency transformer. If this voltage is not limited and exceeds the drain-source voltage of the MOSFET, it will damage the MOSFET. This invention incorporates a protection circuit and a snubber circuit. Clamping protection is achieved through diodes D3 and D4. When the voltage spike exceeds the diode's operating voltage, the diodes conduct, stabilizing the voltage within the allowable drain-source voltage range of the MOSFET and preventing damage. Simultaneously, capacitor C3 and resistor R4 form an RC snubber circuit. Because capacitors cannot change voltage abruptly, the rise rate of the voltage spike is reduced, resulting in better EMI performance.

[0024] The two secondary windings of this invention output a stable 16V voltage after transformation, which is then rectified by diodes and output to the IGBT unit.

[0025] Although specific embodiments of this utility model have been described in detail with reference to the accompanying drawings, this should not be construed as limiting the scope of protection of this patent. Various modifications and variations that can be made by those skilled in the art without inventive effort within the scope described in the claims still fall within the scope of protection of this patent.

Claims

1. An IGBT drive power supply circuit suitable for a high-voltage heater of a new energy vehicle, characterized in that, Comprise: Flyback power supply chip and MOS tube; the pin EN of flyback power supply chip is connected with input power supply, the pin GATE of flyback power supply chip is connected with the G pole of MOS tube; the D pole of MOS tube is connected with high-frequency transformer; High-frequency transformer is provided with 2 secondary windings, which are secondary winding M1 and secondary winding M2 respectively; the output ends of two secondary windings are connected with two IGBT units respectively, one IGBT unit is connected with the positive pole of high-voltage heater power supply, and one IGBT unit is connected with the negative pole of high-voltage heater power supply; diode D1 and capacitor C1 are connected on secondary winding M1, and diode D2 and capacitor C2 are connected on secondary winding M2; High-frequency transformer is connected with absorption circuit and protection circuit in parallel, absorption circuit comprises capacitor C3 and resistor R4, and protection circuit comprises two reverse series-connected diodes D3 and D4.

2. The IGBT drive power supply circuit suitable for a high-voltage heater of a new energy vehicle according to claim 1, characterized in that: The input power supply voltage of flyback power supply chip is 4V-60V, and resistor R1 is arranged between input power supply and flyback power supply chip. 3.The IGBT drive power supply circuit for high-voltage heater of new energy vehicle according to claim 1, characterized in that: The pin RFB of flyback power supply chip is connected between the D pole of MOS tube and high-frequency transformer, and resistor R2 is arranged; the pin SENSE of flyback power supply chip is connected with the S pole of MOS tube and then grounded, and resistor R3 is arranged on the grounding wire.

4. The IGBT drive power supply circuit suitable for a high-voltage heater of a new energy vehicle according to claim 1, characterized in that: The capacitance of capacitor C3 of absorption circuit is 100pF, the rated voltage is 50V, the resistance value of resistor R4 is 200Ω-250Ω; the capacitance of capacitor C1 and capacitor C2 on secondary winding is 10μF respectively, and the rated voltage is 25V.

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