Induction heating power supply based on double ARM

Abstract

The utility model relates to an induction heating power supply based on double ARM, which comprises a main circuit and a control circuit, the main circuit comprises a molded case circuit breaker QF, a rectifier bridge BD1, an IGBT1, an IGBT2, a resistor R1, an inductor L0, a high-frequency filter capacitor C11, an absorption capacitor C13, an absorption capacitor C14 and a filter capacitor C4, an external three-phase alternating current is connected to the rectifier bridge BD1 after passing through the molded case circuit breaker QF, and the rectifier bridge BD1 is connected to the control circuit. The two ends of the rectifier bridge BD1 are connected in parallel with the high-frequency filter capacitor C11, the voltage output end of the rectifier bridge BD1 is connected with one end of the buffer porcelain tube resistor R1, and the other end of the buffer porcelain tube resistor R1 is connected with one end of the inductor L0. The utility model has the advantages that the three-phase AC voltage processing unit can realize the function of automatically detecting the phase sequence, ensures the correct steering of the three-phase fan, and timely radiates the heat of the equipment.

Description

Technical Field

[0001] The utility model relates to an induction heating power supply based on double ARMs, and belongs to the field of induction heating power supplies. Background Art

[0002] At present, the induction heating power supplies widely used in the industrial field are mainly divided into two categories: analog circuit control and digital circuit control.

[0003] Analog circuit controlled induction heating power supplies generally only have power and current modes, which can achieve basic heating. The control parameters are not easy to modify and have poor flexibility. If process parameters or temperature control mode are required, other control units must be plugged in, such as external PLC units.

[0004] The induction heating power supply controlled by digital circuits has been developed in recent years. It has high control accuracy and flexible software design. At present, most conventional induction heating power supplies use DSP control structure. However, DSP does not have floating point operations. To achieve faster and more accurate control, CPLD or other external control units are required, which makes the main control system more complicated. Utility Model Content

[0005] In order to overcome the defects of the prior art and solve the problems of low digitalization degree and complex control system of the existing induction heating power supply, the utility model provides an induction heating power supply based on dual ARM. The technical solution of the utility model is:

[0006] An induction heating power supply based on dual ARM, including a main circuit and a control circuit, wherein the main circuit includes a molded case circuit breaker QF, a rectifier bridge BD1, IGBT1, IGBT2, a high-frequency filter capacitor C11, an absorption capacitor C13, an absorption capacitor C14 and a filter capacitor C4, and an external three-phase AC power is connected to the rectifier bridge BD1 after passing through the molded case circuit breaker QF, and the high-frequency filter capacitor C11 is connected in parallel at both ends of the rectifier bridge BD1, and the positive electrode of the rectifier bridge BD1 is connected to one end of a sampling resistor R7, one end of a resistor R2 and the positive electrodes of IGBT1 and IGBT2, and the negative electrodes of the IGBT1 and IGBT2 are connected. The output end of IGBT1 is connected to one end of the primary side of the medium frequency transformer TR1 through the shunt R3, and the output end of IGBT2 is connected to the other end of the primary side of the transformer TR1 through the DC blocking capacitor C2; the other end of the resistor R2 is connected between the shunt R3 and the filter capacitor C4; the IGBT1 and IGBT2 are connected in parallel with the absorption capacitor C13 and the absorption capacitor C14; one end of the filter capacitor C4 is connected to the positive electrode of the rectifier bridge BD1, and the other end is connected between the resistor R3 and the negative electrodes of the IGBT1 and IGBT2; One end of the secondary side of the frequency transformer TR1 is connected to the resonant capacitor C20, the other end of the resonant capacitor C20 is connected to the induction heating load, and the other end of the induction heating load is connected back to the secondary side of the transformer TR1; the three output ends of the molded case circuit breaker QF are connected to the three-phase AC voltage signal processing unit of the control circuit through sampling resistors R4, R5 and R6 respectively to obtain the three-phase AC voltage; the other end of the sampling resistor R7 is connected to the DC voltage signal processing unit of the control circuit to obtain the DC bus voltage; the two ends of the shunt R3 are connected to the DC current signal processing unit of the control circuit to obtain the bus current; the input of the IGBT1 A current transformer CT1 is installed on the output connection line, and the output end of the current transformer CT1 is connected to the resonant output current processing unit of the control circuit to obtain the resonant output current; the two ends of the resonant capacitor C20 are connected to the voltage transformer VT1, and the output end of the voltage transformer VT1 is connected to the resonant output voltage processing unit to obtain the resonant output voltage; the three output ends of the molded case circuit breaker QF are connected to the fan FAN through the AC contactor KM3; an output end A of the molded case circuit breaker QF and the input neutral line are connected to the input end of the switching power supply P1, and the output end of the switching power supply P1 outputs 24V+ and GND to power the control circuit.

[0007] The control circuit includes a signal acquisition control circuit, a main control board, an LCD screen and a driver board. The signal acquisition control circuit includes a power indicator light HL10, an operation indicator light HL8, an alarm indicator light HL9 and a fan relay K3. The main control board, the LCD screen and the driver board are powered by 24V+. One end of the power indicator light HL10 is connected to GND and the other end is connected to 24V+. One end of the operation indicator light HL8 is connected to GND and the other end is connected to 24V+ after passing through a control switch K1. The control switch K1 is controlled by the indicator light / relay output signal processing unit of the main control board; the alarm indication One end of the lamp HL9 is connected to GND, and the other end is connected to 24V+ after passing through the control switch K2, wherein the control switch K2 is controlled by the indicator light / relay output signal processing unit; one end of the coil of the fan relay KM3.2 is connected to 24V+, and the other end is connected to GND after passing through the control switch K3, wherein the control switch K3 is controlled by the indicator light / relay output signal processing unit, one end of the start-stop switch SB5 is connected to 24V+, and the other end is connected to the switch input signal processing unit of the main control board U1; one end of the emergency stop switch SB6 is connected to 24V+, and the other end is connected to the switch input signal processing unit of the main control board U1.

[0008] The LCD screen is a medical-grade touch configuration screen, which communicates with the ARM1 of the main control board through RS232 or RS485; the driver board amplifies the PWM signal sent by the main control board and drives the IGBT1 and IGBT2 to invert and output.

[0009] The main control board is a dual-core control, including an ARM1 control unit and an ARM2 control unit. The ARM1 control unit is an STM32F4XX series chip, which is responsible for processing AC voltage, temperature and IO signals; the ARM2 control unit is an STM32F3XX series chip, which is responsible for collecting and calculating resonant output current and voltage, and processing PWM output signals; the ARM1 control unit and the ARM2 control unit exchange information through serial port communication; the three-phase AC voltage signal processing unit, the DC voltage signal processing unit, the DC current signal processing unit, the temperature signal processing unit, the communication processing unit, the indicator light / relay output signal processing unit, and the switch input signal processing unit are all connected to the ARM1 control unit; the resonant output voltage processing unit, the resonant output current processing unit, the PWM drive output control unit and the protection control unit are all connected to the ARM2 control unit; and the DC / DC power supply unit supplies power to the ARM1 control unit and the ARM2 control unit.

[0010] The advantages of the utility model are:

[0011] 1. The three-phase AC voltage processing unit can realize the phase sequence automatic detection function to ensure the correct rotation of the three-phase fan and timely dissipate heat for the equipment.

[0012] 2. The relay output signal processing unit can control the start and stop of the fan.

[0013] 3. The screen is an LCD screen, which has better human-computer interaction and is easier to operate than the LED digital display interface used in conventional induction heating power supplies.

[0014] 4. The main control board adopts dual ARM chip control, with high control accuracy and good real-time performance. The ARM1 control unit is responsible for human-machine interaction and the collection and processing of basic parameters, while the ARM2 control unit is only responsible for the collection and processing of frequency and power modulation parameters.

[0015] 5. If there are new functions, only ARM1 needs to be adjusted. The two have their own functions, and the program modification and upgrade are convenient, with high maintainability and scalability.

[0016] 6. The ARM1 control unit is equipped with an embedded operating system and multi-task parallel processing.

[0017] 7. The high-precision PWM resolution of the ARM2 control unit can reach 217ps, which can achieve high-precision output control and meet the single-cycle control mode and protection mode. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is the main circuit diagram of the utility model.

[0019] Figure 2 The utility model is a signal acquisition and control circuit diagram.

[0020] Figure 3 It is a schematic diagram of the connection relationship among the LCD screen, the main control board and the driving board of the utility model.

[0021] Figure 4 It is a structural block diagram of the main control board of the utility model. DETAILED DESCRIPTION

[0022] The present invention is further described below in conjunction with specific embodiments, and the advantages and features of the present invention will become clearer as the description proceeds. However, these embodiments are merely exemplary and do not constitute any limitation to the scope of the present invention. It should be understood by those skilled in the art that the details and forms of the technical solution of the present invention may be modified or replaced without departing from the spirit and scope of the present invention, but these modifications and replacements fall within the scope of protection of the present invention.

[0023] See also Figures 1 to 4The utility model relates to an induction heating power supply based on dual ARM, including a main circuit and a control circuit. The main circuit includes a molded case circuit breaker QF, a rectifier bridge BD1, IGBT1, IGBT2, a high-frequency filter capacitor C11, an absorption capacitor C13, an absorption capacitor C14 and a filter capacitor C4. The external three-phase alternating current passes through the molded case circuit breaker QF and is connected to the rectifier bridge BD1. The two ends of the rectifier bridge BD1 are connected in parallel with the high-frequency filter capacitor C11. The positive electrode of the rectifier bridge BD1 is connected to one end of the sampling resistor R7, one end of the resistor R2, and IGBT1 and IGBT2. The positive electrode of IGBT1 and IGBT2 is connected to the negative electrode of the rectifier bridge BD1 through the shunt R3, the output end of IGBT1 is connected to one end of the primary side of the medium frequency transformer TR1, and the output end of IGBT2 is connected to the other end of the primary side of the transformer TR1 through the DC blocking capacitor C2; the other end of the resistor R2 is connected between the shunt R3 and the filter capacitor C4; the IGBT1 and IGBT2 are arranged in parallel with the absorption capacitor C13 and the absorption capacitor C14; one end of the filter capacitor C4 is connected to the negative electrode of the rectifier bridge BD1, and the other end connected between the resistor R3 and the negative electrodes of the IGBT1 and IGBT2; one end of the secondary side of the intermediate frequency transformer TR1 is connected to the resonant capacitor C20, the other end of the resonant capacitor C20 is connected to the induction heating load, and the other end of the induction heating load is connected back to the secondary side of the transformer TR1; the three output ends of the molded case circuit breaker QF are respectively connected to the three-phase AC voltage signal processing unit 1 of the control circuit through sampling resistors R4, R5 and R6 to obtain the three-phase AC voltage; the other end of the sampling resistor R7 is connected to the DC voltage signal processing unit 2 of the control circuit, The DC bus voltage is obtained; the two ends of the shunt R3 are connected to the DC current signal processing unit of the control circuit to obtain the bus current; the current transformer CT1 is installed on the output end connection line of IGBT1, and the output end of the current transformer CT1 is connected to the communication processing unit of the control circuit to obtain the resonant output current; the two ends of the resonant capacitor C20 are connected to the voltage transformer VT1, and the output end of the voltage transformer VT1 is connected to the resonant output voltage processing unit to obtain the resonant output voltage; the three output ends of the molded case circuit breaker QF are connected to the fan FAN through the AC contactor KM3; the

[0024] An output terminal A of the molded case circuit breaker QF and an input neutral line are connected to the input terminal of the switching power supply P1. The output terminal of P1 outputs 24V+ and GND to power the control circuit.

[0025] The control circuit includes a signal acquisition control circuit, a main control board, an LCD screen and a driver board. The signal acquisition control circuit includes a power indicator light HL10, an operation indicator light HL8, an alarm indicator light HL9 and a fan relay K3. The main control board, the LCD screen and the driver board are powered by 24V+. One end of the power indicator light HL10 is connected to GND, and the other end is connected to 24V+. The light is on when the power is normally powered on; one end of the operation indicator light HL8 is connected to GND, and the other end is connected to 24V+ after passing through the control switch K1, wherein the control switch K1 is controlled by the indicator light / relay output signal processing unit 6 of the main control board, and the power operation When K1 is closed, the light is on; when K1 is disconnected, the light is off when the machine is shut down; one end of the alarm indicator light HL9 is connected to GND, and the other end is connected to 24V+ after passing through the control switch K2, wherein the control switch K2 is controlled by the indicator light / relay output signal processing unit 6, when the power supply is normal, the light is off when K2 is disconnected, and when there is a fault, the light is on when K2 is closed; one end of the coil of the fan relay K3.2 is connected to 24V+, and the other end is connected to GND after passing through the control switch K3, wherein the control switch K3 is controlled by the indicator light / relay output signal processing unit 6, when the power supply is running, the control switch K3 is closed to run the fan; when the power supply is shut down and the internal temperature is normal, the control switch K3 is disconnected to stop the fan. One end of the start-stop switch SB5 is connected to 24V+, and the other end is connected to the switch input signal processing unit 7 of the main control board U1; when SB5 is pressed, 24V+ is input to the main control board, and the equipment runs; when SB5 is reset, 24V+ is disconnected from the main control board, and the equipment stops running; one end of the emergency stop switch SB6 is connected to 24V+, and the other end is connected to the switch input signal processing unit 7 of the main control board U1. When the emergency stop switch SB6 is pressed, 24V+ is disconnected from the main control board, and the equipment stops urgently; when SB6 is reset, 24V+ is input to the main control board, and the equipment runs.

[0026] The LCD screen is a medical-grade touch configuration screen, which communicates with the ARM1 of the main control board via RS232 or RS485; the driver board amplifies the PWM signal sent by the main control board and drives the IGBT1 and IGBT2 inverter output. The LCD screen displays the output current, output power, output voltage, output power, DC bus voltage, resonant frequency, three-phase AC input voltage, system version, system temperature, workpiece temperature, power information, number of startups and other information in real time. The screen can be used to set and modify the working mode, target current, target power, target temperature, target process and other setting parameters.

[0027] The main control board is a dual-core control, including an ARM1 control unit 13 and an ARM2 control unit 14, wherein the ARM1 control unit is an STM32F4XX series chip, responsible for processing AC voltage, temperature and IO signals; the ARM2 control unit 14 is an STM32F3XX series chip, responsible for collecting and calculating resonant output current and voltage, and processing PWM output signals; the ARM1 control unit 13 and the ARM2 control unit 14 exchange information through serial communication; the three-phase AC voltage signal processing unit 1, the DC voltage signal processing unit 2, the DC current signal processing unit 3, the temperature signal processing unit 4, the communication processing unit 5, the indicator light / relay output signal processing unit 6, and the switch input signal processing unit 7 are all connected to the ARM1 control unit; the resonant output voltage processing unit 8, the resonant output current processing unit 9, the PWM drive output control unit 10 and the protection control unit 11 are all connected to the ARM2 control unit; the DC / DC power supply unit 12 supplies power to the ARM1 control unit 13 and the ARM2 control unit 14.

[0028] Among them, the three-phase AC input voltage is connected to the main control board after passing through the voltage dividing resistors R4, R5, and R6, and is processed by the ARM1 control unit to obtain the current voltage value and voltage phase sequence.

[0029] The DC bus voltage is connected to the main control board after passing through the voltage divider resistor R7, and is processed by the ARM1 control unit to obtain the current DC bus voltage value.

[0030] The DC bus current passes through the voltage divider resistor R3 and is connected to the main control board. After processing, it is calculated and processed by the ARM1 control unit to obtain the current DC bus current value.

[0031] Temperature signal processing unit: The temperature signal is connected to the main control board to obtain the current temperature value.

[0032] The communication between the main control board and the LCD screen can be RS232 or RS485.

[0033] Indicator light / relay output signal processing unit: K1, K2 and K3 are connected to the ARM1 control unit for calculation and processing, and the output controls the on and off of K1, K2 and K3.

[0034] Switch input signal processing unit: SB5 and SB6 are connected to the main control board, and the ARM1 control unit performs calculations and processing to determine the current operation, shutdown and emergency stop conditions.

[0035] Resonant output voltage processing unit: The resonant voltage is connected to the main control board after passing through the voltage transformer VT1. After processing, it is calculated and processed by the ARM2 control unit to obtain the current resonant voltage value.

[0036] Resonant output current processing unit: The current passes through the current transformer CT1 and is connected to the main control board. After processing, it is calculated and processed by the ARM2 control unit to obtain the current resonant current value.

[0037] After the PWM drive output control unit, the resonant output voltage processing unit 8 and the resonant output current processing unit 9 are input, they are processed by the ARM2 control unit 14 to obtain a PWM drive signal, which is output to the drive board through the PWM drive output control unit 10.

[0038] Protection control unit: The driver board is connected to the main control board, and it processes and protects according to the feedback signal of the driver board.

[0039] The utility model adopts dual ARM chip control, and the two chips cooperate with each other to realize induction heating.

[0040] The working principle of the utility model is: the main circuit and the control circuit, the dual ARM structure of the main control board collects switch signals, temperature signals and current and voltage signals, and after calculation and processing, controls the frequency and duty cycle of the main circuit IGBT on and off, and displays the working status on the screen at the same time, ultimately achieving the effect of controlling the induction heating power supply to output power stably and reliably and heating the workpiece.

[0041] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes within the technical scope disclosed by the present invention according to the technical scheme and the utility model concept of the present invention, which should be covered by the protection scope of the present invention.

Claims

1. An induction heating power supply based on dual ARM, characterized in that: The invention comprises a main circuit and a control circuit, wherein the main circuit comprises a molded case circuit breaker QF, a rectifier bridge BD1, IGBT1, IGBT2, a high-frequency filter capacitor C11, an absorption capacitor C13, an absorption capacitor C14 and a filter capacitor C4, an external three-phase alternating current is connected to the rectifier bridge BD1 after passing through the molded case circuit breaker QF, the two ends of the rectifier bridge BD1 are connected in parallel with the high-frequency filter capacitor C11, the positive electrode of the rectifier bridge BD1 is connected to one end of a sampling resistor R7, one end of a resistor R2 and the positive electrodes of IGBT1 and IGBT2, the negative electrodes of IGBT1 and IGBT2 are connected to the negative electrode of the rectifier bridge BD1 through a shunt R3, the output end of IGBT1 is connected to one end of the primary side of an intermediate frequency transformer TR1, the output end of IGBT2 is connected to the other end of the primary side of the transformer TR1 through a DC blocking capacitor C2; the other end of the resistor R2 is connected between the shunt R3 and the filter capacitor C4; the IGBT1 and IGBT2 are connected in parallel with the absorption capacitor C13 and the absorption capacitor C14 The filter capacitor C4 is connected to the positive electrode of the rectifier bridge BD1 at one end, and the other end is connected between the resistor R3 and the negative electrodes of the IGBT1 and IGBT2 at the other end; the secondary side of the intermediate frequency transformer TR1 is connected to the resonant capacitor C20 at one end, the other end of the resonant capacitor C20 is connected to the induction heating load, and the other end of the induction heating load is connected back to the secondary side of the transformer TR1; the three output ends of the molded case circuit breaker QF are respectively connected to the three-phase AC voltage signal processing unit of the control circuit through sampling resistors R4, R5 and R6 to obtain the three-phase AC voltage; the other end of the sampling resistor R7 is connected to the DC voltage signal processing unit of the control circuit to obtain the DC bus voltage; the two ends of the shunt R3 are connected to the DC current signal processing unit of the control circuit to obtain the bus current; the output end connection line of the IGBT1 is provided with a current transformer CT1, and the output end of the current transformer CT1 is connected to the resonant output current processing unit of the control circuit to obtain the resonant output current; The two ends of the resonant capacitor C20 are connected to the voltage transformer VT1, and the output end of the voltage transformer VT1 is connected to the resonant output voltage processing unit to obtain the resonant output voltage; the three output ends of the molded case circuit breaker QF are connected to the fan FAN through the AC contactor KM3; an output end A of the molded case circuit breaker QF and the input neutral line are connected to the input end of the switching power supply P1, and the output end of the switching power supply P1 outputs 24V+ and GND to power the control circuit.

2. The induction heating power supply based on dual ARM according to claim 1 is characterized in that: The control circuit includes a signal acquisition control circuit, a main control board, an LCD screen and a driver board. The signal acquisition control circuit includes a power indicator light HL10, an operation indicator light HL8, an alarm indicator light HL9 and a fan relay K3. The main control board, the LCD screen and the driver board are powered by 24V+. One end of the power indicator light HL10 is connected to GND and the other end is connected to 24V+. One end of the operation indicator light HL8 is connected to GND and the other end is connected to 24V+ after passing through a control switch K1. The control switch K1 is controlled by the indicator light / relay output signal processing unit 6 of the main control board; the alarm indication One end of the lamp HL9 is connected to GND, and the other end is connected to 24V+ after passing through the control switch K2, wherein the control switch K2 is controlled by the indicator light / relay output signal processing unit; one end of the coil of the fan relay KM3.2 is connected to 24V+, and the other end is connected to GND after passing through the control switch K3, wherein the control switch K3 is controlled by the indicator light / relay output signal processing unit, one end of the start-stop switch SB5 is connected to 24V+, and the other end is connected to the switch input signal processing unit of the main control board U1; one end of the emergency stop switch SB6 is connected to 24V+, and the other end is connected to the switch input signal processing unit of the main control board U1.

3. The dual ARM-based induction heating power supply according to claim 2 is characterized in that: The LCD screen is a medical-grade touch configuration screen, which communicates with the ARM1 of the main control board through RS232 or RS485; the driver board amplifies the PWM signal sent by the main control board and drives the IGBT1 and IGBT2 to invert and output.

4. The dual ARM-based induction heating power supply according to claim 3 is characterized in that: The main control board is a dual-core control, including an ARM1 control unit and an ARM2 control unit. The ARM1 control unit is an STM32F4XX series chip, which is responsible for processing AC voltage, temperature and IO signals; the ARM2 control unit is an STM32F3XX series chip, which is responsible for collecting and calculating resonant output current and voltage, and processing PWM output signals; the ARM1 control unit and the ARM2 control unit exchange information through serial port communication; the three-phase AC voltage signal processing unit, the DC voltage signal processing unit, the DC current signal processing unit, the temperature signal processing unit, the communication processing unit, the indicator light / relay output signal processing unit, and the switch input signal processing unit are all connected to the ARM1 control unit; the resonant output voltage processing unit, the resonant output current processing unit, the PWM drive output control unit and the protection control unit are all connected to the ARM2 control unit; and the DC / DC power supply unit supplies power to the ARM1 control unit and the ARM2 control unit.

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