A dual-frequency induction heating power supply inverter drive control system and control method

Abstract

This invention discloses a dual-frequency induction heating power supply inverter drive control system and method, belonging to the field of induction heating power supply technology. The dual-frequency induction heating power supply inverter drive control system includes: a rectifier, a filter, and an inverter connected in sequence. The rectifier is connected to a rectifier control circuit, and the inverter is connected to an inverter drive control circuit. The inverter includes three inverter bridge arms. The inverter drive control circuit includes a controller and drive control circuits corresponding to the three inverter bridge arms. The controller collects the inverter current signal and inverter voltage signal from the inverter to generate an inverter frequency control signal, achieving precise control of the switching state of each inverter bridge arm, thereby adjusting the inverter's operating frequency and output power. This invention achieves precise control of the inverter output signal, effectively improving the heating efficiency and uniformity of the dual-frequency induction heating power supply.

Description

Technical Field

[0001] This invention belongs to the field of induction heating power supply technology, specifically relating to a dual-frequency induction heating power supply inverter drive control system and control method. Background Technology

[0002] Induction heating power supplies, as a highly efficient and energy-saving heat treatment device, have been widely used in metal smelting, through-heating, welding, and heat treatment. Compared with traditional heating methods such as coal and gas, induction heating has significant advantages such as fast heating speed, high efficiency, no pollution, and high heating precision. However, with the development of industrialization, especially in the heat treatment of complex-shaped workpieces such as gears, higher performance requirements have been placed on induction heating power supplies, including a wider output power range, more precise frequency regulation capabilities, and the ability to perform multi-frequency coordinated heating.

[0003] Existing induction heating power supplies mainly operate at a single frequency or within a limited frequency range. This method is inefficient when handling complex shapes or multi-material workpieces and makes it difficult to achieve uniform heating. Especially when multi-frequency requirements are needed, the structure and control methods of existing induction heating power supplies limit the flexible adjustment of power and frequency, and cannot effectively meet the requirements for synchronous or switching operation between high and low frequencies.

[0004] In practical applications, for precise heating of complex workpieces such as gears, relying solely on single-frequency or simple frequency adjustment cannot achieve the ideal heating efficiency and uniformity.

[0005] Existing technologies generally suffer from narrow frequency adjustment range, slow response speed, low heating efficiency, and limited power output range. Especially when high-efficiency heating is required for complex workpieces, existing solutions struggle to balance performance and economy. Summary of the Invention

[0006] To solve the above technical problems, the present invention provides a dual-frequency induction heating power supply inverter drive control system, comprising: a rectifier, a filter and an inverter connected in sequence, wherein the rectifier is connected to a rectifier control circuit and the inverter is connected to an inverter drive control circuit.

[0007] The inverter includes a first inverter bridge arm, a second inverter bridge arm, and a third inverter bridge arm; the first inverter bridge arm includes a first upper inverter bridge arm and a first lower inverter bridge arm, the first upper inverter bridge arm includes an anti-parallel insulated-gate bipolar transistor T1 and a diode D1, and the first lower inverter bridge arm includes an anti-parallel insulated-gate bipolar transistor T2 and a diode D2; the second inverter bridge arm includes a second upper inverter bridge arm and a second lower inverter bridge arm, the second upper inverter bridge arm includes an anti-parallel insulated-gate bipolar transistor T3 and a diode D3, and the second lower inverter bridge arm includes an anti-parallel insulated-gate bipolar transistor T4 and a diode D4; the third inverter bridge arm includes a third upper inverter bridge arm and a third lower inverter bridge arm, the third upper inverter bridge arm includes an anti-parallel insulated-gate bipolar transistor T5 and a diode D5, and the third lower inverter bridge arm includes an anti-parallel insulated-gate bipolar transistor T6 and a diode D6;

[0008] The inverter drive control circuit includes a controller, a first inverter bridge arm drive control circuit, a second inverter bridge arm drive control circuit, and a third inverter bridge arm drive control circuit. The first, second, and third inverter bridge arm drive control circuits are all connected to the output terminal of the controller. The input terminal of the controller is connected to an inverter current signal acquisition circuit for sampling the inverter current signal and an inverter voltage signal acquisition circuit for sampling the inverter voltage signal. In this circuit, the collector of the insulated gate bipolar transistor (IGBT) is connected to the cathode of the diode, and the emitter of the IGBT is connected to the anode of the diode.

[0009] A method for driving and controlling a dual-frequency induction heating power supply inverter includes the following steps:

[0010] Step 1: The inverter current signal acquisition circuit samples the inverter current signal and outputs the inverter current signal to the controller; the inverter voltage signal acquisition circuit samples the inverter voltage signal and outputs the inverter voltage signal to the controller.

[0011] Step 2: The controller processes the inverter voltage and inverter current signals to obtain the actual power factor angle feedback signal of the inverter.

[0012] Step 3: The controller compares the actual power factor angle with the target power factor angle to obtain the power factor angle deviation value. Based on this deviation value, it generates an inverter frequency control signal, which is used to dynamically adjust the inverter's output frequency. The inverter frequency control signal is transmitted through the first inverter arm drive control circuit, the second inverter arm drive control circuit, or the third inverter arm drive control circuit to each insulated gate bipolar transistor in the first, second, or third inverter arm of the corresponding inverter, enabling precise control of the switching state of each insulated gate bipolar transistor.

[0013] The present invention has the following beneficial effects:

[0014] This invention employs a multi-arm inverter structure, including the coordinated operation of the first, second, and third inverter arms, combined with an optimized resonant network, to achieve precise control of the synchronous or independent output of high-frequency and low-frequency inverter signals. This effectively improves the heating efficiency and uniformity of the dual-frequency induction heating power supply. The inverter drive control circuit of this invention integrates advanced real-time sampling and closed-loop feedback control strategies. Through high-precision acquisition of inverter voltage and current signals, it dynamically adjusts the inverter output frequency and power, ensuring rapid response and stable operation of the system under complex working conditions. The dual-frequency induction heating power supply inverter drive control system of this invention has a wide output power range, flexibly adjustable from 10kW to 500kW, significantly expanding the heating application range of complex-shaped metal workpieces (such as gears), while simultaneously meeting the multi-frequency, multi-target heat treatment needs in industrial scenarios. Attached Figure Description

[0015] Figure 1 The diagram shows the structure of the dual-frequency induction heating power supply inverter drive control system of the present invention, wherein 1-rectifier, 2-filter, 3-inverter, 4-rectifier control circuit, and 5-inverter drive control circuit.

[0016] Figure 2 This is a structural block diagram of the inverter drive control circuit of the present invention, wherein 301-first inverter bridge arm, 302-second inverter bridge arm, 303-third inverter bridge arm, 501-controller, 502-first inverter bridge arm drive control circuit, 503-second inverter bridge arm drive control circuit, 504-third inverter bridge arm drive control circuit, 505-inverter current signal acquisition circuit, and 506-inverter voltage signal acquisition circuit;

[0017] Figure 3 This is a circuit diagram showing the connection between the inverter drive control circuit and the inverter of the present invention, wherein 3-inverter, 502-first inverter bridge arm drive control circuit, 503-second inverter bridge arm drive control circuit, and 504-third inverter bridge arm drive control circuit. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0019] like Figure 1As shown, the dual-frequency induction heating power supply inverter drive control system of this embodiment includes: a rectifier 1, a filter 2, and an inverter 3 connected in sequence. The rectifier 1 is connected to a rectifier control circuit 4, and the inverter 3 is connected to an inverter drive control circuit 5. Under the control of the rectifier control circuit 4, the rectifier 1 converts the input AC power into DC power, providing a stable DC output for the filter 2. The rectifier 1 itself converts AC power to DC power, while the rectifier control circuit 4 monitors and regulates the rectification process to ensure the stability and efficiency of the DC power output. The filter 2 smooths the rectified DC signal, removing ripple interference and ensuring the purity and stability of the input signal to the inverter 3. The inverter 3 converts the smoothed DC power back into AC power, achieving high-frequency and low-frequency AC output. Rectifier 1 provides input energy, filter 2 optimizes the power signal, and inverter 3, through the precise regulation of inverter drive control circuit 5, completes the dynamic adjustment of the frequency and power of the output signal of inverter 3 (the power signal of dual-frequency induction heating power supply) to meet the high-efficiency heating requirements of complex workpieces.

[0020] The inverter 3 includes a first inverter bridge arm 301, a second inverter bridge arm 302, and a third inverter bridge arm 303, which convert direct current into alternating current. The first inverter bridge arm 301 includes a first upper inverter bridge arm and a first lower inverter bridge arm. The first upper inverter bridge arm includes an anti-parallel insulated-gate bipolar transistor (IGBT) T1 and a diode D1, and the first lower inverter bridge arm includes an anti-parallel IGBT T2 and a diode D2. The second inverter bridge arm 302 includes a second upper inverter bridge arm and a second lower inverter bridge arm. The second upper inverter bridge arm includes an anti-parallel IGBT T3 and a diode D3, and the second lower inverter bridge arm includes an anti-parallel IGBT T4 and a diode D4. The third inverter bridge arm 303 includes a third upper inverter bridge arm and a third lower inverter bridge arm. The third upper inverter bridge arm includes an anti-parallel IGBT T5 and a diode D5, and the third lower inverter bridge arm includes an anti-parallel IGBT T6 and a diode D6.

[0021] In this configuration, anti-parallel connection means that the collector of the insulated gate bipolar transistor (IGBT) is connected to the cathode of the diode, and the emitter of the IGBT is connected to the anode of the diode.

[0022] like Figure 2As shown, the inverter drive control circuit 5 includes a controller 501, a first inverter bridge arm drive control circuit 502, a second inverter bridge arm drive control circuit 503, and a third inverter bridge arm drive control circuit 504. The first inverter bridge arm drive control circuit 502, the second inverter bridge arm drive control circuit 503, and the third inverter bridge arm drive control circuit 504 are all connected to the output terminal of the controller 501. The input terminal of the controller 501 is connected to an inverter current signal acquisition circuit 505 for sampling the inverter current signal and an inverter voltage signal acquisition circuit 506 for sampling the inverter voltage signal.

[0023] like Figure 3 As shown, in this embodiment, the first inverter bridge arm drive control circuit 502 includes a field-effect transistor Q1, resistors R1 and R2, a thyristor Q2, a diode D7, a capacitor C1, a resistor R12, and an inductor L1. Capacitor C1 and inductor L1 are connected in parallel to form a resonant network. The drain of the field-effect transistor Q1 and one end of the resonant network are both connected to the gate of an insulated-gate bipolar transistor T1. The other end of the resonant network is connected to the gate of an insulated-gate bipolar transistor T2. The source of the field-effect transistor Q1 is connected to one end of resistor R2, and the other end of resistor R2 is grounded. The gate of the field-effect transistor Q1 is connected to the cathode of diode D7, and the anode of diode D7 is connected to one end of resistor R1. The other end of resistor R1 is connected to the power supply voltage VCC output terminal of filter 2 via a relay. The relay is connected to the control signal output terminal of controller 501. Resistor R12 is connected between the gate and source of field-effect transistor Q1. The anode of thyristor Q2 is connected to the anode of diode D7. The cathode of thyristor Q2 is grounded. The gate of thyristor Q2 is connected to the source of field-effect transistor Q1. In this embodiment, field-effect transistor Q1 is an N-channel enhancement-mode field-effect transistor, but it can also be other types of field-effect transistors. Insulated-gate bipolar transistors T1 and T2 are N-channel insulated-gate bipolar transistors, but they can also be other types of insulated-gate bipolar transistors.

[0024] like Figure 3As shown, in this embodiment, the second inverter bridge arm drive control circuit 503 includes a field-effect transistor Q3, resistors R3 and R4, a thyristor Q4, a diode D8, a capacitor C2, a resistor R32, and an inductor L2. Capacitor C2 and inductor L2 are connected in parallel to form a resonant network. The drain of the field-effect transistor Q3 and one end of the resonant network are both connected to the gate of the insulated-gate bipolar transistor T3. The other end of the resonant network is connected to the gate of the insulated-gate bipolar transistor T4. The source of the field-effect transistor Q3 is connected to one end of resistor R4, and the other end of resistor R4 is grounded. The gate of the field-effect transistor Q3 is connected to the cathode of diode D8, and the anode of diode D8 is connected to one end of resistor R3. The other end of resistor R3 is connected to the power supply voltage VCC output terminal of filter 2 via a relay. The relay is connected to the control signal output terminal of controller 501. Resistor R32 is connected between the gate and source of field-effect transistor Q3. The anode of thyristor Q4 is connected to the anode of diode D8. The cathode of thyristor Q4 is grounded. The gate of thyristor Q4 is connected to the source of field-effect transistor Q3. In this embodiment, field-effect transistor Q3 is an N-channel enhancement-mode field-effect transistor, but it can also be other types of field-effect transistors. Insulated-gate bipolar transistors T3 and T4 are N-channel insulated-gate bipolar transistors, but they can also be other types of insulated-gate bipolar transistors.

[0025] like Figure 3 As shown, in this embodiment, the third inverter bridge arm drive control circuit 504 includes a field-effect transistor Q5, resistors R5 and R6, a thyristor Q6, a diode D9, a capacitor C3, a resistor R52, and an inductor L3. Capacitor C3 and inductor L3 are connected in parallel to form a resonant network. The drain of the field-effect transistor Q5 and one end of the resonant network are both connected to the gate of an insulated-gate bipolar transistor T5. The other end of the resonant network is connected to the gate of the insulated-gate bipolar transistor T6. The source of the field-effect transistor Q5 is connected to one end of resistor R6, and the other end of resistor R6 is grounded. The gate of the field-effect transistor Q5 is connected to the cathode of diode D9, and the anode of diode D9 is connected to one end of resistor R5. The other end of resistor R5 is connected to the power supply voltage VCC output terminal of filter 2 via a relay. The relay is connected to the control signal output terminal of controller 501. Resistor R52 is connected between the gate and source of field-effect transistor Q5. The anode of thyristor Q6 is connected to the anode of diode D9. The cathode of thyristor Q6 is grounded. The gate of thyristor Q6 is connected to the source of field-effect transistor Q5. In this embodiment, field-effect transistor Q5 is an N-channel enhancement-mode field-effect transistor, but it can also be other types of field-effect transistors. Insulated-gate bipolar transistors T5 and T6 are N-channel insulated-gate bipolar transistors, but they can also be other types of insulated-gate bipolar transistors.

[0026] In this embodiment, the controller 501 is an ARM processor.

[0027] The dual-frequency induction heating power supply inverter drive control method of this embodiment includes the following steps:

[0028] Step 1: The inverter current signal acquisition circuit 505 samples the inverter current signal and outputs the inverter current signal to the controller 501; the inverter voltage signal acquisition circuit 506 samples the inverter voltage signal and outputs the inverter voltage signal to the controller 501.

[0029] Step 2: Controller 501 processes the inverter voltage signal and inverter current signal to obtain the actual power factor angle feedback signal of inverter 3;

[0030] Step 3: The controller 501 compares the actual power factor angle with the target power factor angle to obtain the power factor angle deviation value. Based on this deviation value, it generates an inverter frequency control signal, which is used to dynamically adjust the output frequency of the inverter. The inverter frequency control signal is transmitted through the first inverter arm drive control circuit 502, the second inverter arm drive control circuit 503, or the third inverter arm drive control circuit 504 to the insulated gate bipolar transistors in the corresponding first inverter arm 301, second inverter arm 302, or third inverter arm 303, thereby achieving precise control of the switching state of each insulated gate bipolar transistor. This ensures the phase matching of the inverter voltage signal and inverter current signal output by the inverter 3. In other words, by adjusting the phase of the inverter voltage signal and inverter current signal output by the inverter 3, the inverter 3 maintains the target power factor angle, improving the stability and efficiency of the system operation.

[0031] The power factor angle refers to the phase difference between the output voltage and output current of inverter 3. By controlling the phase difference between the inverter current signal and the inverter current signal using the dual-frequency induction heating power supply inverter drive control method of this invention, inverter 3 can achieve a fixed target power factor angle, thereby ensuring optimal matching between the output power of inverter 3 and load requirements, reducing power loss of inverter 3, and improving the heating efficiency of the dual-frequency induction heating power supply.

[0032] The specific method for controlling the switching state transition of the insulated gate bipolar transistor (IGBT) described in step three is as follows: After the circuit is powered on, thyristor Q2 is in the off state. Controller 501 controls the relay to connect the power supply voltage VCC output terminal of filter 2 to resistor R1. The power supply voltage VCC, through resistor R1 and diode D7, provides the turn-on voltage to the gate of field-effect transistor Q1, causing Q1 to conduct. After Q1 conducts, the resonant network stores energy, and the current flowing through the first inverter bridge arm drive control circuit 502 rises rapidly. Simultaneously, the controller generates a trigger signal through the first inverter bridge arm drive control circuit 502 to synchronously control T1 and T2, ensuring that the conduction states of T1 and T2 meet the energy conversion requirements of the resonant network. By dynamically adjusting T1 and T2, the current distribution is effectively optimized and the resonant efficiency is improved. By adjusting the switching states of T1 and T2, the controller ensures that the resonant network operates in its optimal state. When the current rises to the point that the voltage across the sampling resistor R2 reaches the gate trigger voltage of thyristor Q2, thyristor Q2 turns on. Then, the anode voltage of thyristor Q2 is clamped at 0.8V by its on-state voltage drop. The anode voltage of thyristor Q2 is then stepped down by the buck diode D7 and applied to the gate of field-effect transistor Q1, so that the gate-source voltage of field-effect transistor Q1 is lower than the threshold voltage of field-effect transistor Q1, ensuring that field-effect transistor Q1 is reliably turned off.

[0033] The specific method for controlling the switching state transition of the insulated gate bipolar transistor (IGBT) described in step three is as follows: After the circuit is powered on, thyristor Q4 is in the off state. Controller 501 controls the relay to connect the power supply voltage VCC output terminal of filter 2 to resistor R3. The power supply voltage VCC, through resistor R3 and diode D8, provides the gate turn-on voltage for field-effect transistor Q3, causing Q3 to conduct. After Q3 conducts, the resonant network stores energy, and the current flowing through the second inverter bridge arm drive control circuit 503 rises rapidly. Simultaneously, the controller generates a trigger signal through the second inverter bridge arm drive control circuit 503 to synchronously control T3 and T4, ensuring that the conduction states of T3 and T4 meet the energy conversion requirements of the resonant network. By dynamically adjusting T3 and T4, the current distribution is effectively optimized and the resonant efficiency is improved. By adjusting the switching states of T3 and T4, the controller ensures that the resonant network operates in its optimal state. When the current rises to the point that the voltage across the sampling resistor R4 reaches the gate trigger voltage of thyristor Q4, thyristor Q4 turns on. Then, the anode voltage of thyristor Q4 is clamped at 0.8V by its on-state voltage drop. The anode voltage of thyristor Q4 is then stepped down by the buck diode D8 and applied to the gate of field-effect transistor Q3, so that the gate-source voltage of field-effect transistor Q3 is lower than the threshold voltage of field-effect transistor Q3, ensuring that field-effect transistor Q3 is reliably turned off.

[0034] The specific method for controlling the switching state transition of the insulated gate bipolar transistor (IGBT) described in step three is as follows: After the circuit is powered on, thyristor Q6 is in the off state. Controller 501 controls the relay to connect the output terminal of the power supply voltage VCC of filter 2 to resistor R5. The power supply voltage VCC, through resistor R5 and diode D9, provides the gate turn-on voltage for MOSFET Q5, causing MOSFET Q5 to conduct. After MOSFET Q5 conducts, the resonant network stores energy, and the current flowing through the third inverter bridge arm drive control circuit 504 rises rapidly. Simultaneously, the controller generates a trigger signal through the third inverter bridge arm drive control circuit 504 to synchronously control T5 and T6, ensuring that the conduction states of T5 and T6 meet the energy conversion requirements of the resonant network. By dynamically adjusting T5 and T6, the current distribution is effectively optimized and the resonant efficiency is improved. By adjusting the switching states of T5 and T6, the controller ensures that the resonant network operates in its optimal state. When the current rises to the point that the voltage across the sampling resistor R6 reaches the gate trigger voltage of thyristor Q6, thyristor Q6 turns on. Then, the anode voltage of thyristor Q6 is clamped at 0.8V by its on-state voltage drop. The anode voltage of thyristor Q6 is then stepped down by the buck diode D9 and applied to the gate of field-effect transistor Q5, so that the gate-source voltage of field-effect transistor Q5 is lower than the threshold voltage of field-effect transistor Q5, ensuring that field-effect transistor Q5 is reliably turned off.

[0035] The above description is merely a preferred embodiment of the present invention and does not constitute any limitation on the present invention. Any simple modifications, alterations, or equivalent structural changes made to the above embodiments based on the technical essence of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A dual-frequency induction heating power inverter drive control system, characterized by, The application relates to a rectifier (1), a filter (2) and an inverter (3) connected in sequence, the rectifier (1) is connected with a rectifier control circuit (4), and the inverter (3) is connected with an inverter drive control circuit (5). The inverter (3) comprises a first inverter bridge arm (301), a second inverter bridge arm (302) and a third inverter bridge arm (303); the first inverter bridge arm (301) comprises a first upper inverter bridge arm and a first lower inverter bridge arm, the first upper inverter bridge arm comprises an anti-parallel insulated gate bipolar transistor T1 and a diode D1, and the first lower inverter bridge arm comprises an anti-parallel insulated gate bipolar transistor T2 and a diode D2; the second inverter bridge arm (302) comprises a second upper inverter bridge arm and a second lower inverter bridge arm, the second upper inverter bridge arm comprises an anti-parallel insulated gate bipolar transistor T3 and a diode D3, and the second lower inverter bridge arm comprises an anti-parallel insulated gate bipolar transistor T4 and a diode D4; the third inverter bridge arm (303) comprises a third upper inverter bridge arm and a third lower inverter bridge arm, the third upper inverter bridge arm comprises an anti-parallel insulated gate bipolar transistor T5 and a diode D5, and the third lower inverter bridge arm comprises an anti-parallel insulated gate bipolar transistor T6 and a diode D6; The inverter drive control circuit (5) comprises a controller (501), a first inverter bridge arm drive control circuit (502), a second inverter bridge arm drive control circuit (503) and a third inverter bridge arm drive control circuit (504), the first inverter bridge arm drive control circuit (502), the second inverter bridge arm drive control circuit (503) and the third inverter bridge arm drive control circuit (504) are connected with the output end of the controller (501), the input end of the controller (501) is connected with an inverter current signal acquisition circuit (505) for sampling an inverter current signal and an inverter voltage signal acquisition circuit (506) for sampling an inverter voltage signal; wherein the anti-parallel connection is that the cathode of the diode connected with the collector of the insulated gate bipolar transistor and the anode of the diode connected with the emitter of the insulated gate bipolar transistor. ​ The first, second and third inverter bridge arm drive control circuits (502, 503, 504) have the same structure; the first inverter bridge arm drive control circuit (502) comprises a field effect transistor Q1, a resistor R1, a resistor R2, a thyristor Q2, a diode D7, a capacitor C1, a resistor R12 and an inductor L1, the capacitor C1 and the inductor L1 are connected in parallel to form a resonance network, the drain of the field effect transistor Q1 and one end of the resonance network are connected to the gate of an insulated gate bipolar transistor T1, the other end of the resonance network is connected to the gate of an insulated gate bipolar transistor T2, the source of the field effect transistor Q1 is connected to one end of the resistor R2, the other end of the resistor R2 is grounded, the gate of the field effect transistor Q1 is connected to the cathode of the diode D7, one end of the resistor R1 is connected to the anode of the diode D7, the other end of the resistor R1 is connected to the power voltage VCC output end of a filter (2) through a relay, the relay is connected to the control signal output end of a controller (501), the resistor R12 is connected between the gate and the source of the field effect transistor Q1, the anode of the thyristor Q2 is connected to the anode of the diode D7, the cathode of the thyristor Q2 is grounded, and the gate of the thyristor Q2 is connected to the source of the field effect transistor Q1; the field effect transistor Q1 is an N-channel enhancement mode field effect transistor, and the insulated gate bipolar transistors T1 and T2 are N-channel insulated gate bipolar transistors.

2. The dual frequency induction heating power inverter drive control system of claim 1, wherein: The second inverter bridge arm drive control circuit (503) comprises a field effect transistor Q3, a resistor R3, a resistor R4, a thyristor Q4, a diode D8, a capacitor C2, a resistor R32 and an inductor L2, the capacitor C2 and the inductor L2 are connected in parallel to form a resonance network, the drain of the field effect transistor Q3 and one end of the resonance network are connected to the gate of an insulated gate bipolar transistor T3, the other end of the resonance network is connected to the gate of an insulated gate bipolar transistor T4, the source of the field effect transistor Q3 is connected to one end of the resistor R4, the other end of the resistor R4 is grounded, the gate of the field effect transistor Q3 is connected to the cathode of the diode D8, one end of the resistor R3 is connected to the anode of the diode D8, the other end of the resistor R3 is connected to the power voltage VCC output end of a filter (2) through a relay, the relay is connected to the control signal output end of a controller (501), the resistor R32 is connected between the gate and the source of the field effect transistor Q3, the anode of the thyristor Q4 is connected to the anode of the diode D8, the cathode of the thyristor Q4 is grounded, and the gate of the thyristor Q4 is connected to the source of the field effect transistor Q3; the field effect transistor Q3 is an N-channel enhancement mode field effect transistor, and the insulated gate bipolar transistors T3 and T4 are N-channel insulated gate bipolar transistors.

3. The dual frequency induction heating power inverter drive control system of claim 1, wherein: The third inverter bridge arm drive control circuit (504) comprises a field effect transistor Q5, a resistor R5, a resistor R6, a thyristor Q6, a diode D9, a capacitor C3, a resistor R52 and an inductor L3, the capacitor C3 and the inductor L3 are connected in parallel to form a resonance network, the drain of the field effect transistor Q5 and one end of the resonance network are connected to the gate of an insulated gate bipolar transistor T5, the other end of the resonance network is connected to the gate of an insulated gate bipolar transistor T6, the source of the field effect transistor Q5 is connected to one end of the resistor R6, the other end of the resistor R6 is grounded, the gate of the field effect transistor Q5 is connected to the cathode of the diode D9, one end of the resistor R5 is connected to the anode of the diode D9, the other end of the resistor R5 is connected to the power voltage VCC output end of the filter (2) through a relay, the relay is connected to the control signal output end of the controller (501), the resistor R52 is connected between the gate and the source of the field effect transistor Q5, the anode of the thyristor Q6 is connected to the anode of the diode D9, the cathode of the thyristor Q6 is grounded, and the gate of the thyristor Q6 is connected to the source of the field effect transistor Q5; wherein the field effect transistor Q5 is an N-channel enhancement mode field effect transistor, and the insulated gate bipolar transistors T5 and T6 are N-channel insulated gate bipolar transistors.

4. The dual frequency induction heating power inverter drive control system of any one of claims 1 to 3, wherein: The controller (501) is an ARM processor.

5. A dual-frequency induction heating power inverter drive control method using the dual-frequency induction heating power inverter drive control system according to any one of claims 1 to 4, characterized by The method comprises the following steps: Step one, the inverter current signal acquisition circuit (505) samples the inverter current signal and outputs the inverter current signal to the controller (501); the inverter voltage signal acquisition circuit (506) samples the inverter voltage signal and outputs the inverter voltage signal to the controller (501); Step two, the controller (501) processes the inverter voltage signal and the inverter current signal to obtain an actual power factor angle feedback signal of the inverter (3); the power factor angle refers to the phase difference between the output voltage and the output current of the inverter; Step three, the controller (501) compares the actual power factor angle with a target power factor angle to obtain a power factor angle deviation value, generates an inverter frequency control signal according to the deviation value, and the signal is used to dynamically adjust the output frequency of the inverter (3); the inverter frequency control signal is transmitted to each insulated gate bipolar transistor in the first inverter bridge arm (301), the second inverter bridge arm (302) or the third inverter bridge arm (303) of the corresponding inverter (3) through the first inverter bridge arm drive control circuit (502), the second inverter bridge arm drive control circuit (503) or the third inverter bridge arm drive control circuit (504), so as to realize precise control of the switching state of each insulated gate bipolar transistor. In step three, the precise control of the switching state of each insulated gate bipolar transistor is as follows: after the circuit is powered on, the thyristor Q2 is in the off state, the controller (501) controls the relay to connect the power supply voltage VCC output end of the filter (2) and the resistor R1, and the power supply voltage VCC provides an opening voltage for the gate of the field effect transistor Q1 through the resistor R1 and the diode D7, so that the field effect transistor Q1 is turned on; after the field effect transistor Q1 is turned on, the resonant network stores energy, and the current flowing through the first inverter arm drive control circuit (502) rises rapidly; at the same time, the controller (501) generates a trigger signal through the first inverter arm drive control circuit (502) to synchronously control the insulated gate bipolar transistors T1 and T2, so that the on state of the insulated gate bipolar transistors T1 and T2 meets the energy conversion requirement of the resonant network; when the current rises to the gate trigger voltage of the thyristor Q2 at both ends of the sampling resistor R2, the thyristor Q2 is turned on; thereafter, the anode voltage of the thyristor Q2 is clamped at 0.8V by the on-state voltage drop thereof; the anode voltage of the thyristor Q2 is reduced by the voltage reduction diode D7 and then applied to the gate of the field effect transistor Q1, so that the gate-source voltage of the field effect transistor Q1 is lower than the threshold voltage of the field effect transistor Q1, thereby ensuring that the field effect transistor Q1 is reliably turned off; wherein the field effect transistor Q1 is an N-channel enhancement mode field effect transistor, and the insulated gate bipolar transistors T1 and T2 are N-channel insulated gate bipolar transistors.

6. The dual-frequency induction heating power inverter drive control method according to claim 5, characterized by: The second inverter arm drive control circuit (503) comprises a field effect transistor Q3, a resistor R3, a resistor R4, a thyristor Q4, a diode D8, a capacitor C2, a resistor R32 and an inductor L2, the capacitor C2 and the inductor L2 are connected in parallel to form a resonant network, the drain of the field effect transistor Q3 and one end of the resonant network are connected to the gate of the insulated gate bipolar transistor T3, the other end of the resonant network is connected to the gate of the insulated gate bipolar transistor T4, the source of the field effect transistor Q3 is connected to one end of the resistor R4, the other end of the resistor R4 is grounded, the gate of the field effect transistor Q3 is connected to the cathode of the diode D8, the anode of the diode D8 is connected to one end of the resistor R3, the other end of the resistor R3 is connected to the power supply voltage VCC output end of the filter (2) through a relay, the relay is connected to the control signal output end of the controller (501), the resistor R32 is connected between the gate and the source of the field effect transistor Q3, the anode of the thyristor Q4 is connected to the anode of the diode D8, the cathode of the thyristor Q4 is grounded, and the gate of the thyristor Q4 is connected to the source of the field effect transistor Q3. In step three, the precise control of the state of each insulated gate bipolar transistor switch is as follows: after the circuit is powered on, the thyristor Q4 is in the off state, the controller (501) controls the relay to connect the power supply voltage VCC output end of the filter (2) and the resistor R3, and the power supply voltage VCC provides an opening voltage for the gate of the field effect transistor Q3 through the resistor R3 and the diode D8, so that the field effect transistor Q3 is turned on; after the field effect transistor Q3 is turned on, the resonant network stores energy, and the current flowing through the second inverter arm drive control circuit (503) rises rapidly; at the same time, the controller (501) generates a trigger signal through the second inverter arm drive control circuit (503) to synchronously control the insulated gate bipolar transistors T3 and T4, so that the on state of the insulated gate bipolar transistors T3 and T4 meets the energy conversion requirements of the resonant network; when the current rises to a voltage across the sampling resistor R4 that reaches the gate trigger voltage of the thyristor Q4, the thyristor Q4 is turned on; thereafter, the anode voltage of the thyristor Q4 is clamped at 0.8V by the on-state voltage drop thereof; the anode voltage of the thyristor Q4 is reduced by the voltage reduction diode D8 and applied to the gate of the field effect transistor Q3, so that the gate-source voltage of the field effect transistor Q3 is lower than the threshold voltage of the field effect transistor Q3, thereby ensuring that the field effect transistor Q3 is reliably turned off; wherein the field effect transistor Q3 is an N-channel enhancement mode field effect transistor, and the insulated gate bipolar transistors T3 and T4 are N-channel insulated gate bipolar transistors.

7. The dual-frequency induction heating power inverter drive control method of claim 5, wherein: The third inverter arm drive control circuit (504) includes a field effect transistor Q5, a resistor R5, a resistor R6, a thyristor Q6, a diode D9, a capacitor C3, a resistor R52, and an inductor L3. The capacitor C3 and the inductor L3 are connected in parallel to form a resonant network. The drain of the field effect transistor Q5 and one end of the resonant network are connected to the gate of the insulated gate bipolar transistor T5. The other end of the resonant network is connected to the gate of the insulated gate bipolar transistor T6. The source of the field effect transistor Q5 is connected to one end of the resistor R6, and the other end of the resistor R6 is grounded. The gate of the field effect transistor Q5 is connected to the cathode of the diode D9, and the anode of the diode D9 is connected to one end of the resistor R5. The other end of the resistor R5 is connected to the power supply voltage VCC output end of the filter (2) through a relay, and the relay is connected to the control signal output end of the controller (501). A resistor R52 is connected between the gate and the source of the field effect transistor Q5. The anode of the thyristor Q6 is connected to the anode of the diode D9, and the cathode of the thyristor Q6 is grounded. The gate of the thyristor Q6 is connected to the source of the field effect transistor Q5. In step three, the precise control of the state of each insulated gate bipolar transistor switch is as follows: after the circuit is powered on, the thyristor Q6 is in the off state, the controller (501) controls the relay to connect the power supply voltage VCC output end of the filter (2) and the resistor R5, and the power supply voltage VCC provides an opening voltage for the gate of the field effect transistor Q5 through the resistor R5 and the diode D9, so that the field effect transistor Q5 is turned on; after the field effect transistor Q5 is turned on, the resonant network stores energy, and the current flowing through the third inverter arm drive control circuit (504) rises rapidly; at the same time, the controller (501) generates a trigger signal through the third inverter arm drive control circuit (504) to synchronously control the insulated gate bipolar transistors T5 and T6, so that the on-off state of the insulated gate bipolar transistors T5 and T6 meets the energy conversion requirements of the resonant network; when the current rises to the gate trigger voltage of the thyristor Q6 at both ends of the sampling resistor R6, the thyristor Q6 is turned on; thereafter, the anode voltage of the thyristor Q6 is clamped at 0.8V by the on-state voltage drop; the anode voltage of the thyristor Q6 is reduced by the voltage reduction diode D9 and applied to the gate of the field effect transistor Q5, so that the gate-source voltage of the field effect transistor Q5 is lower than the threshold voltage of the field effect transistor Q5, ensuring that the field effect transistor Q5 is reliably turned off; wherein the field effect transistor Q5 is an N-channel enhancement mode field effect transistor, and the insulated gate bipolar transistors T5 and T6 are N-channel insulated gate bipolar transistors.

8. The dual-frequency induction heating power inverter drive control method according to any one of claims 5 to 7, characterized by: The controller (501) is an ARM processor.

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