Dual-frequency induction heating power supply inverter driving control system and control method

Abstract

The invention discloses a dual-frequency induction heating power supply inverter drive control system and control method, and belongs to the technical field of induction heating power supplies. The double-frequency induction heating power supply inverter driving control system comprises a rectifier, a filter and an inverter which are connected in sequence, the rectifier is connected with a rectifier control circuit, and the inverter is connected with an inverter driving control circuit; the inverter comprises three inverter bridge arms. The inverter drive control circuit comprises a controller and drive control circuits corresponding to the three inverter bridge arms. The controller generates an inverter frequency control signal by collecting an inverter current signal and an inverter voltage signal of the inverter so as to realize accurate control of the on-off state of each inverter bridge arm, thereby adjusting the working frequency and the output power of the inverter. According to the invention, the accurate control of the output signal of the inverter is realized, and the heating efficiency and uniformity of the dual-frequency induction heating power supply are effectively improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of induction heating power supplies, and in particular relates to a dual-frequency induction heating power supply inverter drive control system and a control method. Background Art

[0002] As an energy-efficient heat treatment equipment, induction heating power supply has been widely used in metal smelting, heat penetration, welding and heat treatment. Compared with traditional heating methods such as coal and gas, induction heating has the significant advantages of fast heating speed, high efficiency, no pollution and high heating accuracy. However, with the development of industrialization, especially in the heat treatment application of complex-shaped workpieces such as gears, higher performance requirements are put forward for induction heating power supply, including wider output power range, more accurate frequency adjustment capability and multi-frequency coordinated heating capability.

[0003] Existing induction heating power supplies are still mainly based on heating with a single frequency or a limited frequency range. This method is inefficient when processing complex shapes or multi-material workpieces, and it is difficult to achieve uniform heating. Especially under multi-frequency requirements, the structure and control method of existing induction heating power supplies limit the flexible adjustment of power and frequency, and cannot effectively meet the synchronization or switching work requirements of high and low frequencies.

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

[0005] Existing technologies generally have problems such as narrow frequency adjustment range, slow response speed, low heating efficiency and limited power output range. Especially when it comes to the demand for efficient heating of complex workpieces, existing solutions are difficult to balance performance and economy. Summary of the invention

[0006] In order to solve the above technical problems, the present invention provides a dual-frequency induction heating power inverter drive control system, comprising: 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;

[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 inverter bridge arm drive control circuit, the second inverter bridge arm drive control circuit and the third inverter bridge arm drive control circuit are all connected to the output end of the controller, and the input end of the controller is connected to an inverter current signal acquisition circuit for sampling an inverter current signal and an inverter voltage signal acquisition circuit for sampling an inverter voltage signal; wherein, the anti-parallel connection is that the collector of the insulated gate bipolar transistor is connected to the cathode of the diode, and the emitter of the insulated gate bipolar transistor is connected to the anode of the diode.

[0009] A dual-frequency induction heating power inverter drive control method comprises 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 signal and the inverter current signal to obtain an actual power factor angle feedback signal of the inverter;

[0012] Step three, the controller compares the actual power factor angle with the target power factor angle to obtain a power factor angle deviation value, and 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; the inverter frequency control signal is transmitted to each insulated gate bipolar transistor in the first inverter bridge arm, the second inverter bridge arm or the third inverter bridge arm of the corresponding inverter through the first inverter bridge arm drive control circuit, the second inverter bridge arm drive control circuit or the third inverter bridge arm drive control circuit, to accurately control the switching state of each insulated gate bipolar transistor.

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

[0014] The present invention adopts a multi-bridge-arm inverter structure, including the coordinated operation of the first inverter bridge arm, the second inverter bridge arm and the third inverter bridge arm, and combines it with an optimized resonant network to achieve precise control of the synchronous or independent output of the high-frequency and low-frequency output signals of the inverter, and effectively improves the heating efficiency and uniformity of the dual-frequency induction heating power supply. The inverter drive control circuit of the present invention integrates advanced real-time sampling and closed-loop feedback control strategies, and dynamically adjusts the frequency and power of the inverter output through high-precision acquisition of the inverter voltage signal and the current signal, ensuring the rapid response and stable operation of the system under complex working conditions. The dual-frequency induction heating power inverter drive control system of the present invention has a wide output power range, which can be flexibly adjusted between 10kW and 500kW, significantly expanding the heating application range of complex-shaped metal workpieces (such as gears, etc.), while meeting the multi-band and multi-target heat treatment requirements in industrial scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0016] Figure 2 It 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, 506-inverter voltage signal acquisition circuit;

[0017] Figure 3 It is a circuit schematic diagram of the inverter drive control circuit of the present invention connected to the inverter, wherein 3-inverter, 502-first inverter bridge arm drive control circuit, 503-second inverter bridge arm drive control circuit, 504-third inverter bridge arm drive control circuit. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present 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 inverter drive control system of this embodiment includes: a rectifier 1, a filter 2 and an inverter 3 connected in sequence, wherein 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, and provides a stable DC output for the filter 2. Among them, the function of the rectifier 1 itself is to convert AC power into DC power, and the rectifier control circuit 4 is responsible for monitoring and adjusting the rectification process to ensure the stability and efficiency of the DC power output. The filter 2 smoothes the DC signal output by the rectifier, removes ripple interference, and ensures the purity and stability of the input signal of the inverter 3. The inverter 3 inverts the smoothed DC power into AC power to achieve high-frequency and low-frequency AC output. The rectifier 1 provides input energy, the filter 2 optimizes the power signal, and the inverter 3 dynamically adjusts the frequency and power of the output signal of the inverter 3 (the power signal of the dual-frequency induction heating power supply) through the precise regulation of the inverter drive control circuit 5 to meet the efficient heating requirements of complex workpieces.

[0020] The inverter 3 comprises a first inverter bridge arm 301 , a second inverter bridge arm 302 and a third inverter bridge arm 303 , and uses the first inverter bridge arm 301 , the second inverter bridge arm 302 and the third inverter bridge arm 303 to invert 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 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 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 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 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 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;

[0021] The anti-parallel connection means that the collector of the insulated gate bipolar transistor is connected to the cathode of the diode, and the emitter of the insulated gate bipolar transistor 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 end of the controller 501, and the input end of the controller 501 is connected to 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.

[0023] like Figure 3 As shown, in this embodiment, the first inverter bridge arm drive control circuit 502 includes 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 resonant network, the drain of the field effect transistor Q1 and one end of the resonant network are connected to the gate of the insulated gate bipolar transistor T1, the other end of the resonant network is connected to the gate of the 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, the anode of the diode D7 is connected to one end of the resistor R1 The other end of the resistor R1 is connected to the power supply voltage VCC output terminal of the filter 2 through a relay, the relay is connected to the control signal output terminal of the controller 501, a 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; in this embodiment, the field effect transistor Q1 is an N-channel enhancement type field effect transistor, and can also be other types of field effect transistors, the insulated gate bipolar transistor T1 and the insulated gate bipolar transistor T2 are N-channel insulated gate bipolar transistors, and 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, 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 terminal of the filter 2 through a relay, the relay is connected to the control signal output terminal of the controller 501, a 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 this embodiment, the field effect transistor Q3 is an N-channel enhancement type field effect transistor, and can also be other types of field effect transistors, the insulated gate bipolar transistor T3 and the insulated gate bipolar transistor T4 are N-channel insulated gate bipolar transistors, and 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, 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, 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, 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 terminal of the filter 2 through a relay, the relay is connected to the control signal output terminal 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, 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; in this embodiment, the field effect transistor Q5 is an N-channel enhancement type field effect transistor, and can also be other types of field effect transistors, the insulated gate bipolar transistor T5 and the insulated gate bipolar transistor T6 are N-channel insulated gate bipolar transistors, and 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 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: 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;

[0030] Step three, the controller 501 compares the actual power factor angle with the target power factor angle to obtain a power factor angle deviation value, and generates an inverter frequency control signal according to the deviation value, which is used to dynamically adjust the output frequency of the inverter; the inverter frequency control signal is transmitted to the corresponding insulated gate bipolar transistors in the first inverter bridge arm 301, the second inverter bridge arm 302 or the third inverter bridge arm 303 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 achieve precise control of the switching state of each insulated gate bipolar transistor, thereby ensuring the phase matching of the inverter voltage signal and the inverter current signal output by the inverter 3, that is, by adjusting the phase of the inverter voltage signal and the inverter current signal output by the inverter 3, the inverter 3 maintains the target power factor angle, thereby improving the stability and efficiency of the system operation.

[0031] The power factor angle ‌ refers to the phase difference between the output voltage and the output current of the inverter 3. By the dual-frequency induction heating power inverter drive control method of the present invention, the phase difference between the inverter current signal and the inverter current signal is controlled to achieve a fixed target power factor angle for the inverter 3, thereby ensuring the best match between the output power of the inverter 3 and the load demand, reducing the power loss of the inverter 3 and improving the heating efficiency of the dual-frequency induction heating power supply.

[0032] The specific method for realizing the switch state conversion control of the insulated gate bipolar transistor described in step 3 is: 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 a turn-on 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 bridge arm drive control circuit 502 rises rapidly. At the same time, the controller generates a trigger signal through the first inverter bridge arm drive control circuit 502 to synchronously control T1 and T2, so that the conduction state of T1 and T2 meets the energy conversion requirements of the resonant network. By dynamically adjusting T1 and T2, the current distribution is effectively optimized and the resonance efficiency is improved. The controller ensures that the resonant network can operate in the best working state by adjusting the switch states of T1 and T2. When the current rises to the point where the voltage across the sampling resistor R2 reaches the gate trigger voltage of the thyristor Q2, the thyristor Q2 is turned on; thereafter, the anode voltage of the thyristor Q2 is clamped at 0.8V by its conduction voltage drop; the anode voltage of the thyristor Q2 is stepped down by the step-down diode D7 and then added 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.

[0033] The specific method for realizing the switch state conversion control of the insulated gate bipolar transistor described in step 3 is: 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 a turn-on 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 bridge arm drive control circuit 503 rises rapidly. At the same time, the controller generates a trigger signal through the second inverter bridge arm drive control circuit 503 to synchronously control T3 and T4, so that the conduction state of T3 and T4 meets the energy conversion requirements of the resonant network. By dynamically adjusting T3 and T4, the current distribution is effectively optimized and the resonance efficiency is improved. The controller ensures that the resonant network can operate in the best working state by adjusting the switch states of T3 and T4. When the current rises to the point where the voltage across the sampling resistor R4 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 its conduction voltage drop; the anode voltage of the thyristor Q4 is stepped down by the step-down diode D8 and then added 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.

[0034] The specific method for realizing the switch state conversion control of the insulated gate bipolar transistor described in step 3 is: 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 a turn-on 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 bridge arm drive control circuit 504 rises rapidly. At the same time, the controller generates a trigger signal through the third inverter bridge arm drive control circuit 504 to synchronously control T5 and T6, so that the conduction state of T5 and T6 meets the energy conversion requirements of the resonant network. By dynamically adjusting T5 and T6, the current distribution is effectively optimized and the resonance efficiency is improved. The controller ensures that the resonant network can operate in the best working state by adjusting the switch states of T5 and T6. When the current rises to the point where the voltage across the sampling resistor R6 reaches the gate trigger voltage of the thyristor Q6, the thyristor Q6 is turned on; thereafter, the anode voltage of the thyristor Q6 is clamped at 0.8V by its conduction voltage drop; the anode voltage of the thyristor Q6 is stepped down by the step-down diode D9 and then added 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, thereby ensuring that the field effect transistor Q5 is reliably turned off.

[0035] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent structural change made to the above embodiment based on the technical essence of the present invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. A dual-frequency induction heating power inverter drive control system, characterized in that: include: A rectifier (1), a filter (2) and an inverter (3) connected in sequence, the rectifier (1) being connected to a rectifier control circuit (4), and the inverter (3) being connected to 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, 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 first lower inverter bridge arm The second lower inverter bridge arm comprises an insulated gate bipolar transistor T3 and a diode D3 connected in anti-parallel, and the second lower inverter bridge arm comprises an insulated gate bipolar transistor T4 and a diode D4 connected in anti-parallel; 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 insulated gate bipolar transistor T5 and a diode D5 connected in anti-parallel, and the third lower inverter bridge arm comprises an insulated gate bipolar transistor T6 and a diode D6 connected in anti-parallel; 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 all connected to the output end of the controller (501); the input end of the controller (501) is connected to 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 collector of the insulated gate bipolar transistor is connected to the cathode of the diode, and the emitter of the insulated gate bipolar transistor is connected to the anode of the diode.

2. The dual-frequency induction heating power inverter drive control system according to claim 1, characterized in that: 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 resonant network, the drain of the field effect transistor Q1 and one end of the resonant network are both connected to the gate of the insulated gate bipolar transistor T1, the other end of the resonant network is connected to the gate of the 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, and the diode D An anode of 7 is connected to one end of a resistor R1, the other end of the resistor R1 is connected to an output end of a power supply voltage VCC of a filter (2) via a relay, the relay is connected to a control signal output end of a controller (501), a resistor R12 is connected between the gate and source of the field effect transistor Q1, an anode of the thyristor Q2 is connected to an anode of a diode D7, a cathode of the thyristor Q2 is grounded, and a gate of the thyristor Q2 is connected to the source of the field effect transistor Q1; wherein the field effect transistor Q1 is an N-channel enhancement type field effect transistor, and the insulated gate bipolar transistor T1 and the insulated gate bipolar transistor T2 are N-channel insulated gate bipolar transistors.

3. The dual-frequency induction heating power inverter drive control system according to claim 1, characterized in that: 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 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 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, and the diode D An anode of 8 is connected to one end of a resistor R3, the other end of the resistor R3 is connected to an output end of a power supply voltage VCC of a filter (2) via a relay, the relay is connected to a control signal output end of a controller (501), a resistor R32 is connected between the gate and source of the field effect transistor Q3, an anode of the thyristor Q4 is connected to an anode of a diode D8, a cathode of the thyristor Q4 is grounded, and a gate of the thyristor Q4 is connected to the source of the field effect transistor Q3; wherein the field effect transistor Q3 is an N-channel enhancement type field effect transistor, and the insulated gate bipolar transistor T3 and the insulated gate bipolar transistor T4 are N-channel insulated gate bipolar transistors.

4. The dual-frequency induction heating power inverter drive control system according to claim 1, characterized in that: 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 resonant network, the drain of the field effect transistor Q5 and one end of the resonant network are both 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, 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 diode D An anode of 9 is connected to one end of a resistor R5, the other end of the resistor R5 is connected to an output end of a power supply voltage VCC of a filter (2) via a relay, the relay is connected to a control signal output end of a controller (501), a resistor R52 is connected between the gate and source of the field effect transistor Q5, an anode of the thyristor Q6 is connected to an anode of a diode D9, a cathode of the thyristor Q6 is grounded, and a gate of the thyristor Q6 is connected to a source of the field effect transistor Q5; wherein the field effect transistor Q5 is an N-channel enhancement type field effect transistor, and the insulated gate bipolar transistor T5 and the insulated gate bipolar transistor T6 are N-channel insulated gate bipolar transistors.

5. The dual-frequency induction heating power inverter drive control system according to any one of claims 1 to 4, characterized in that: The controller (501) is an ARM processor.

6. A dual-frequency induction heating power inverter drive control method, characterized in that: The following steps are involved: 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); Step 2: 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); Step 3: The controller (501) compares the actual power factor angle with the target power factor angle to obtain a power factor angle deviation value, and generates an inverter frequency control signal according to the deviation value, wherein the inverter frequency control 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) via 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), thereby realizing accurate control of the switching state of each insulated gate bipolar transistor.

7. The dual-frequency induction heating power inverter drive control method according to claim 6, characterized in that: 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 insulated gate bipolar transistor T1 and a diode D1 connected in anti-parallel, and the first lower inverter bridge arm comprises an insulated gate bipolar transistor T2 and a diode D2 connected in anti-parallel; 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 insulated gate bipolar transistor T3 and a diode D3 connected in anti-parallel, and the second lower inverter bridge arm comprises an insulated gate bipolar transistor T4 and a diode D4 connected in anti-parallel; 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 insulated gate bipolar transistor T5 and a diode D5 connected in anti-parallel, and the third lower inverter bridge arm comprises an insulated gate bipolar transistor T6 and a diode D6 connected in anti-parallel.

8. The dual-frequency induction heating power inverter drive control method according to claim 7, characterized in that: 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 resonant network, the drain of the field effect transistor Q1 and one end of the resonant network are both connected to the gate of the insulated gate bipolar transistor T1, the other end of the resonant network is connected to the gate of the insulated gate bipolar transistor T2, the source of the field effect transistor Q1 is connected to one end of the resistor R2, and the other end of the resistor R2 is connected to ground, the gate of the field effect transistor Q1 is connected to the cathode of the diode D7, the anode of the diode D7 is connected to one end of the resistor R1, the other end of the resistor R1 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), a resistor R12 is connected between the gate and 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; In step 3, the precise control of the switch state of each insulated gate bipolar transistor is specifically 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 a turn-on 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 bridge arm drive control circuit (502) rises rapidly; at the same time, the controller (501) generates a trigger signal through the first inverter bridge arm drive control circuit (502) to synchronously control the insulated gate bipolar transistor T1 and the insulated gate bipolar transistor T2, so that the insulated gate bipolar transistor Q1 is turned on. The conduction states of the gate bipolar transistor T1 and the insulated gate bipolar transistor T2 meet the energy conversion requirements of the resonant network; when the current rises to the point where the voltage across the sampling resistor R2 reaches the gate trigger voltage of the thyristor Q2, the thyristor Q2 is turned on; thereafter, the anode voltage of the thyristor Q2 is clamped at 0.8V by its conduction voltage drop; the anode voltage of the thyristor Q2 is stepped down by the step-down diode D7 and then added 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 type field effect transistor, and the insulated gate bipolar transistor T1 and the insulated gate bipolar transistor T2 are N-channel insulated gate bipolar transistors.

9. The dual-frequency induction heating power inverter drive control method according to claim 7, characterized in that: 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 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 the resistor R4, and the other end of the resistor R4 is connected to ground, 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), a resistor R32 is connected between the gate and 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 3, the precise control of the switch state of each insulated gate bipolar transistor is specifically 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 a turn-on 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 bridge arm drive control circuit (503) rises rapidly; at the same time, the controller (501) generates a trigger signal through the second inverter bridge arm drive control circuit (503) to synchronously control the insulated gate bipolar transistor T3 and the insulated gate bipolar transistor T4, so that the insulated gate bipolar transistor Q3 is turned on. The conduction states of the gate bipolar transistor T3 and the insulated gate bipolar transistor T4 meet the energy conversion requirements of the resonant network; when the current rises to the point where the voltage across the sampling resistor R4 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 its conduction voltage drop; the anode voltage of the thyristor Q4 is stepped down by the step-down diode D8 and then added 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 type field effect transistor, and the insulated gate bipolar transistor T3 and the insulated gate bipolar transistor T4 are N-channel insulated gate bipolar transistors.

10. The dual-frequency induction heating power inverter drive control method according to claim 7, characterized in that: 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 resonant network, the drain of the field effect transistor Q5 and one end of the resonant network are both 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 connected to ground, the gate of the field effect transistor Q5 is connected to the cathode of the diode D9, 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, the relay is connected to the control signal output end of the controller (501), a resistor R52 is connected between the gate and 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; In step 3, the precise control of the switch state of each insulated gate bipolar transistor is specifically 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 a turn-on 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 bridge arm drive control circuit (504) rises rapidly; at the same time, the controller (501) generates a trigger signal through the third inverter bridge arm drive control circuit (504) to synchronously control the insulated gate bipolar transistors T5 and T6. The control makes the conduction state of the insulated gate bipolar transistor T5 and the insulated gate bipolar transistor T6 meet the energy conversion requirements of the resonant network; when the current rises to make the voltage across the sampling resistor R6 reach the gate trigger voltage of the thyristor Q6, the thyristor Q6 is turned on; thereafter, the anode voltage of the thyristor Q6 is clamped at 0.8V by its conduction voltage drop; the anode voltage of the thyristor Q6 is stepped down by the step-down diode D9 and added 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 type field effect transistor, and the insulated gate bipolar transistor T5 and the insulated gate bipolar transistor T6 are N-channel insulated gate bipolar transistors.

11. The dual-frequency induction heating power inverter drive control method according to any one of claims 6 to 10, characterized in that: The controller (501) is an ARM processor.

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