Power supply circuit for driving insulated gate bipolar transistor

Abstract

The invention discloses a power supply circuit for driving an insulated gate bipolar transistor, and belongs to the technical field of insulated gate bipolar transistor driving. The input end of the input filtering module is connected with an input power supply; the clock module is connected with the output end of the input filtering module and used for outputting waveform signals. The signal processing module is connected with the output end of the clock module and outputs a pulse width modulation signal; the power driving module is connected with the output end of the signal processing module and is turned off and turned on under the action of the pulse width modulation signal; the primary side of the isolation transformer is connected with the output end of the power driving module; the rectifier module is connected with the secondary side of the isolation transformer and rectifies the output alternating current into direct current; the output filtering module is connected with the output end of the rectification module. The beneficial effects of the technical scheme are that front-stage and back-stage high voltage isolation is realized, the voltage-resistant isolation performance is relatively high, the magnitude of current flowing through the isolation transformer can be controlled, the output voltage is more stable, the circuit structure is simple, and the cost is low.

Description

Technical Field

[0001] The present invention relates to the technical field of insulated gate bipolar transistor driving, and in particular to a power supply circuit. Background Art

[0002] DC-DC (Direct Current-Direct Current) power supplies are widely used in electronic devices. In order to prevent the high voltage of the subsequent stage from affecting the previous stage, the previous stage circuit is isolated from the subsequent stage circuit. An isolated power supply needs to be provided, especially for the power supply of high-voltage IGBT (Insulate-Gate Bipolar Transistor) drive units of 3000V and above. The closed-loop control circuit will reduce the overall voltage resistance. Under the influence of high voltage, the safety and signal stability of the devices between the previous stage and the subsequent stage cannot be guaranteed.

[0003] In the prior art, the Chinese invention patent with publication number CN211859952U discloses an isolated DC-DC power supply, such as Figure 1 As shown, it includes a control circuit component 1 and a power circuit component 2. The control circuit component 1 includes a power supply network 11, a PWM controller 12, a power tube driver 13, a resistor-capacitor bias network 14 and an isolated feedback module 15. The power circuit component 2 includes an input network 21, a transformer 22, a power component 23 and an output network 24. The isolated feedback module 15 is electrically connected to the input end of the PWM controller 12. The voltage output is stabilized by feeding the output voltage back to the PWM (pulse width modulation) signal end. However, it cannot withstand higher voltages. If a feedback device with a high withstand voltage is used, the manufacturing cost will increase, which is not conducive to the production and promotion of the product. The power supply network 11 and the input network 21 are divided into two input ends, which increases the complexity of the circuit and is inconvenient in practical applications. Summary of the invention

[0004] The object of the present invention is to provide a power supply circuit for driving an insulated gate bipolar transistor to solve the above technical problems;

[0005] A power supply circuit for driving an insulated gate bipolar transistor, comprising:

[0006] An input filter module, wherein an input end of the input filter module is connected to an input power supply;

[0007] A clock module, connected to the output end of the input filter module, for outputting a waveform signal;

[0008] A signal processing module, connected to the output end of the clock module, for processing the waveform state of the waveform signal and outputting a pulse width modulation signal;

[0009] A power driving module, connected to the output end of the signal processing module, receives the pulse width modulation signal, and is turned off and on under the action of the pulse width modulation signal;

[0010] An isolation transformer, wherein the primary side of the isolation transformer is connected to the output end of the power driving module;

[0011] A rectifier module, connected to the secondary side of the isolation transformer, for rectifying the alternating current output by the isolation transformer into direct current;

[0012] The output filter module is connected to the output end of the rectifier module.

[0013] Preferably, the input filtering module comprises:

[0014] A varistor, the varistor is connected in parallel with the input power supply;

[0015] A first electrolytic capacitor is connected in parallel with the varistor.

[0016] Preferably, the clock module comprises:

[0017] A signal generator, connected to the output end of the input filter module, for emitting the waveform signal;

[0018] A timer, connected to the output end of the signal generator, for receiving the waveform signal and timing;

[0019] A timer, connected to the output end of the signal generator, for counting the waveform signal;

[0020] A crystal oscillator is connected to the signal generator and is used to drive the signal generator to emit the waveform signal.

[0021] Preferably, the magnetic core of the isolation transformer is made of ferrite material, the primary winding and the secondary winding of the isolation transformer are both wound with multi-layer insulating enameled wire, and an insulating layer is provided between the primary winding and the secondary winding.

[0022] Preferably, the signal processing module comprises:

[0023] A transistor, the base of which is connected to the output end of the clock module, and is used to amplify the waveform signal to obtain an amplified signal;

[0024] A first integrated circuit chip, wherein the input end of the first integrated circuit chip is connected to the collector of the transistor, and is used to receive the amplified signal and perform filtering and signal amplification processing to output an analog signal;

[0025] A second integrated circuit chip, wherein the input end of the second integrated circuit chip is connected to the output end of the first integrated circuit chip, and is used for receiving and converting the analog signal into the pulse width modulation signal and then outputting it.

[0026] Preferably, the first integrated circuit chip is an analog signal integrated circuit chip, and the second integrated circuit chip is a digital signal integrated circuit chip.

[0027] Preferably, the rectifier module is a diode.

[0028] Preferably, the output filtering module comprises:

[0029] an inductor, a first end of the inductor being connected to a first output end of the rectifier module;

[0030] A second electrolytic capacitor, wherein a first end of the second electrolytic capacitor is connected to the second end of the inductor, and a second end of the second electrolytic capacitor is connected to the second output end of the rectifier module.

[0031] Preferably, it also includes:

[0032] A power supply module, wherein the input end of the power supply module is connected to the input filter module, and the output end of the power supply module is respectively connected to the clock module and the signal processing module, and is used to convert the voltage of the input power supply and transmit it to the clock module and the signal processing module.

[0033] Preferably, the power supply module is a voltage converter.

[0034] The beneficial effects of the present invention are: high voltage isolation between the front and rear stages is achieved through an isolation transformer, which has a higher withstand voltage isolation performance, can control the amount of current flowing through the isolation transformer, so that the output voltage is more stable, the circuit structure is simple, and the cost is low. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 is a schematic diagram of an isolated DC-DC power supply in the prior art;

[0036] Figure 2 is a schematic diagram of a power supply circuit for driving an insulated gate bipolar transistor of the present invention;

[0037] Figure 3 is a circuit diagram of an input filter module of the present invention;

[0038] Figure 4 It is a circuit diagram of the output filter module of the present invention.

[0039] In the attached figure: 1. Control circuit components; 11. Power supply network; 12. PWM controller; 13. Power tube driver; 14. RC bias network; 15. Isolation feedback module; 2. Power circuit components; 21. Input network; 22. Transformer; 23. Power components; 24. Output network; 3. Input filter module; 31. Power supply module; 4. Clock module; 5. Signal processing module; 6. Power drive module; 7. Isolation transformer; 8. Rectifier module; 9. Output filter module; 10. Load. DETAILED DESCRIPTION

[0040] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0041] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0042] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, but they are not intended to limit the present invention.

[0043] A power supply circuit for driving an insulated gate bipolar transistor, such as Figure 2 As shown, including,

[0044] An input filter module 3, wherein an input end of the input filter module 3 is connected to an input power supply;

[0045] The clock module 4 is connected to the output end of the input filter module 3 and is used to output a waveform signal;

[0046] The signal processing module 5 is connected to the output end of the clock module 4 and is used to process the waveform state of the waveform signal and output a pulse width modulation signal;

[0047] The power driving module 6 is connected to the output end of the signal processing module 5, receives the pulse width modulation signal, and is turned off and on under the action of the pulse width modulation signal;

[0048] An isolation transformer 7, wherein the primary side of the isolation transformer 7 is connected to the output end of the power driving module 6;

[0049] The rectifier module 8 is connected to the secondary side of the isolation transformer 7 and is used to rectify the AC power output by the isolation transformer 7 into DC power;

[0050] The output filter module 9 is connected to the output end of the rectifier module 8 .

[0051] Specifically, the present invention provides a power supply circuit for driving an insulated gate bipolar transistor, wherein the output end of an output filter module 9 is connected to a load 10, which may be a post-stage IGBT drive unit or a drive substrate. An isolation transformer 7 is used to isolate the high-voltage side from the low-voltage side to ensure the safety and anti-interference capability of the circuit. An open-loop control method is adopted, and a square wave signal of a fixed frequency sent by a clock module 4 is transmitted to a power drive module 6 through a signal processing module 5 to control the current change of the isolation transformer 7, thereby realizing a voltage change. The signal is then rectified and filtered to be converted into a stable signal for output, and has a high withstand voltage performance, a simple circuit structure, and a more stable output voltage.

[0052] In a preferred embodiment, referring to Figure 3 , the input filter module 3 includes,

[0053] The varistor R is connected in parallel with the input power supply;

[0054] The first electrolytic capacitor C1 is connected in parallel with the varistor R.

[0055] Specifically, the input power supply is directly connected to the input filter module 3 to filter the power supply input voltage signal to make the input signal more stable and avoid damage to the device due to voltage mutation.

[0056] The input filter module 3 includes but is not limited to a varistor R and a first electrolytic capacitor C1.

[0057] When the input voltage ripple is large, the ripple of the input power supply voltage can be reduced by the first electrolytic capacitor C1.

[0058] When the input voltage has a large upward change, the varistor R can consume this part of the energy and protect the subsequent circuit from being damaged by excessive voltage.

[0059] In a preferred embodiment, the clock module 4 includes:

[0060] A signal generator, connected to the output end of the input filter module 3, for sending a waveform signal;

[0061] A timer, connected to the output end of the signal generator, for receiving the waveform signal and timing;

[0062] A timer, connected to the output end of the signal generator, for counting the waveform signal;

[0063] Crystal oscillator, connected to the signal generator, is used to drive the signal generator to send out a waveform signal.

[0064] Specifically, the output of the signal generator is directly connected to the clock input terminal of the timer and the counter, providing a reference clock signal for the timer and the counter.

[0065] At the same time, in some cases (such as when it is necessary to work in conjunction with a crystal oscillator to adjust the frequency), the output of the signal generator is connected to the input of the oscillation circuit of the crystal oscillator.

[0066] The signal generator generates an electrical signal with a specific frequency and waveform (such as a common square wave, sine wave, etc.) as a basic signal source for the entire clock module 4 .

[0067] For example, a signal generator can generate a square wave signal with a frequency of 50kHz. This square wave signal is the time reference for subsequent circuits to perform timing, timing, and signal processing operations.

[0068] The accuracy and stability of the square wave signal frequency are crucial to the timing control of the entire circuit. If the output frequency of the signal generator is unstable, it will lead to inaccurate timing of the timer and counter, which will in turn affect the working timing of the entire circuit, disrupt the timing of the IGBT drive signal, affect the normal switching of the IGBT, and even damage power devices such as the IGBT.

[0069] The clock input terminal of the timer is connected to the output of the signal generator and receives the reference clock signal for timing operation.

[0070] The output of the timer is connected to the start terminal of the timer (when sequential control timing operation is required).

[0071] The timer generates a timing signal or performs a specific operation after a preset time interval based on the clock signal provided by the signal generator.

[0072] For example, a 1ms timing cycle is set, and when the timing reaches 1ms, the timer outputs a trigger signal. The trigger signal can be used to control the start or stop time of the operation in the signal processing module 5, ensuring that each operation in the circuit is performed in a predetermined time sequence, thereby improving the reliability and predictability of the circuit operation.

[0073] For example, during the IGBT driving process, it is necessary to regularly control the rising and falling edge times of the IGBT gate voltage. The timer can provide an accurate time reference to ensure that the IGBT switching operation is performed at the correct time, avoiding problems such as increased power loss or device damage caused by switching timing errors.

[0074] The clock input of the timer is connected to the output of the signal generator to obtain the reference clock signal for counting operation. The output of the timer is connected to the oscillation circuit of the crystal oscillator.

[0075] A timer counts clock signals to measure time intervals or accumulated time.

[0076] For example, the timer can count the number of cycles of the signal processing module 5 processing the signal, and when a certain count value is reached, a signal is triggered to notify the system to perform an operation, such as adjusting the parameters of the signal processing module 5 or optimizing the output of the power driving module 6.

[0077] The timer provides a control method based on time counting, which helps to adjust the working state of the circuit according to time-related conditions during the operation of the circuit, ensure that the circuit can respond correctly in different working stages, and improve the adaptability and stability of the circuit to various working conditions.

[0078] For example, during the current control process on the primary side of the isolation transformer 7, the output current of the power drive module is adjusted according to the count value of the timer to achieve precise control of the input current of the isolation transformer 7, thereby ensuring that the secondary side of the isolation transformer 7 can output stable voltage and current to meet the power supply requirements of the high-voltage IGBT drive.

[0079] The crystal oscillator is connected to an oscillation circuit (including components such as an amplifier). On the one hand, the output end of the oscillation circuit is fed back to the crystal oscillator itself to maintain the stable oscillation of the crystal oscillator. On the other hand, the output of the oscillation circuit is connected to the signal processing module 5 to provide a stable clock frequency signal for the signal processing module 5.

[0080] Crystal oscillators use the piezoelectric effect of crystals to generate highly stable clock frequency signals.

[0081] For example, the crystal oscillator frequencies are 1MHz, 10MHz, etc.

[0082] In this power supply circuit, the stable frequency signal provided by the crystal oscillator is crucial to ensure the timing accuracy and stability of the entire circuit.

[0083] When processing the waveform signal input by the clock module 4, the signal processing module 5 needs a stable clock reference to accurately perform signal processing operations, such as data sampling, signal conversion, etc.

[0084] The stable frequency provided by the crystal oscillator can enable various digital circuits in the signal processing module 5 (such as logic circuits in the IC chip) to work according to precise timing, avoiding signal processing errors caused by clock frequency drift.

[0085] In the power driving module 6 , a stable clock frequency also helps to accurately control the switching frequency of the IGBT, improve driving efficiency, and reduce power loss and electromagnetic interference.

[0086] The stability of a crystal oscillator is usually higher than that of an ordinary signal generator, especially under environmental conditions such as temperature changes and power supply voltage fluctuations. It can maintain a relatively stable frequency output and provide a reliable clock basis for the entire high-voltage IGBT drive power circuit.

[0087] The clock module 4 includes but is not limited to a signal generator, a timer, a counter, and a crystal oscillator, and outputs a signal waveform of a specific frequency as a stable source input signal for the signal processing module 5 .

[0088] In a preferred embodiment, the magnetic core of the isolation transformer 7 is made of ferrite material, the primary winding and the secondary winding of the isolation transformer 7 are both wound with multi-layer insulating enameled wire, and an insulating layer is provided between the primary winding and the secondary winding.

[0089] Specifically, the magnetic core of the isolation transformer 7 is made of high-frequency ferrite material, which has the characteristics of high magnetic permeability, low loss and high resistivity to meet the requirements of high-frequency working environment.

[0090] The primary winding and secondary winding are wound with multi-layer insulating enameled wire, and an insulating layer made of high-performance insulating materials such as polyimide film is provided between the windings. It can efficiently transmit electric energy under high-frequency signals, effectively isolate the electrical connection between the input side and the output side, realize high-voltage isolation between the front and rear stages, and ensure stable and reliable operation of the power supply circuit under high-frequency and high-isolation requirements. It has high withstand voltage isolation performance, and can control the current flowing through the isolation transformer 7, so that the output voltage is more stable.

[0091] In a preferred embodiment, the signal processing module 5 includes:

[0092] A transistor, the base of which is connected to the output end of the clock module 4, and is used to amplify the waveform signal to obtain an amplified signal;

[0093] A first integrated circuit chip, wherein the input end of the first integrated circuit chip is connected to the collector of the transistor, and is used to receive the amplified signal and perform filtering and signal amplification processing, and output an analog signal;

[0094] A second integrated circuit chip, the input end of the second integrated circuit chip is connected to the output end of the first integrated circuit chip, and is used to receive and convert the analog signal into a pulse width modulation signal and then output it;

[0095] The first integrated circuit chip is an analog signal integrated circuit chip, and the second integrated circuit chip is a digital signal integrated circuit chip.

[0096] Specifically, the transistor can be a bipolar junction transistor (BJT) or a field effect transistor (FET). When the transistor is a bipolar junction transistor, the base of the transistor is connected to the output end of the clock module 4 to receive the input signal from the clock module 4, the collector of the transistor is connected to the input end of the subsequent first integrated circuit chip, and the emitter of the transistor is grounded.

[0097] When the transistor is a field effect transistor, the gate of the transistor is connected to the output end of the clock module 4 to receive the input signal from the clock module 4, the drain of the transistor is connected to the input end of the subsequent first integrated circuit chip, and the source of the transistor is grounded.

[0098] The transistor plays a major role in signal amplification and switch control in the signal processing module 5. When receiving the waveform signal from the clock module 4, the transistor can amplify the signal current according to the level change of the signal (for example, for BJT, the base voltage change will control the collector current change), enhance the signal driving ability, and enable the subsequent circuit to better receive and process the signal.

[0099] Transistors can also be used as electronic switches to control the on and off of signals according to the high and low levels of the input signals, and to perform preliminary shaping or modulation on the input waveform.

[0100] For example, converting a weak input signal into a signal waveform with a certain driving capability and suitable for subsequent chip processing lays the foundation for subsequent analog signal integrated circuit chip processing.

[0101] The input end of the analog signal integrated circuit chip is connected to the output end of the transistor to receive the signal processed by the transistor. The output end of the analog signal integrated circuit chip is connected to the input end of the digital signal integrated circuit chip.

[0102] Analog signal integrated circuit chips can realize functions such as signal filtering (removing unnecessary frequency components to further stabilize the signal), signal linear amplification (enhancing the signal amplitude according to a certain proportion while maintaining the linear characteristics of the signal), and signal modulation (for example, adjusting the frequency, phase, etc. of the signal).

[0103] For example, analog signal integrated circuit chips filter and accurately amplify analog signals output by transistors that contain certain noise or inappropriate amplitude, making the signal waveform more regular and the amplitude more in line with the requirements of subsequent digital signal processing, and transforming the analog signal to the final desired stable and appropriate waveform state, providing high-quality analog input signals for subsequent digital signal integrated circuit chips to accurately perform analog-to-digital conversion and other operations.

[0104] The input end of the digital signal integrated circuit chip is connected to the output end of the analog signal integrated circuit chip, receives the processed analog signal, and then processes it through its internal digital circuit (such as an analog-to-digital converter, logic circuit, etc.), and finally outputs a PWM (pulse width modulation signal) signal from its output end and sends the signal to the power drive module 6.

[0105] The digital signal integrated circuit chip first converts the received analog signal into a digital signal through an internal analog-to-digital converter (ADC), and then uses the internal digital logic circuit (such as counters, comparators, registers, etc.) to process the digital signal according to pre-set algorithms and logic.

[0106] For example, the digital signal levels at different times are compared by a comparator, and the output digital signal state is adjusted according to the comparison result, and then after appropriate encoding and other operations, a PWM signal is finally generated. This PWM signal can accurately control the switching action of the power drive module 6, thereby realizing effective control of the current in the isolation transformer 7, which is the key link for the entire circuit to realize power conversion and drive control, ensuring that the entire high-voltage IGBT drive power supply circuit can work in the desired manner and provide stable and appropriate power supply for the drive substrate.

[0107] The clock module 4 outputs a 150kHz square wave signal, which enters the signal processing module 5. The signal processing module 5 processes the signal through internal transistors, analog signal integrated circuit chips and digital signal integrated circuit chips. Among them, the digital signal integrated circuit chip performs frequency division operation on the 150kHz signal.

[0108] After receiving the 30kHz PWM signal, the power driving module 6 performs on-off operations according to the high and low levels of the PWM signal. When the PWM signal is at a high level, the power driving module 6 outputs a current of a certain magnitude, so that current passes through the primary side of the isolation transformer 7; when the PWM signal is at a low level, the output current of the power driving module 6 changes in magnitude or is turned off, thereby changing the current on the primary side of the isolation transformer 7. A current change signal with a frequency of 30kHz is generated on the primary side of the isolation transformer 7, and the corresponding alternating current is generated on the secondary side of the isolation transformer 7 through the principle of electromagnetic induction. The rectifier module 8 rectifies this alternating current into direct current, and the output filter module 9 filters the direct current to provide a stable direct current power supply for the IGBT drive substrate, ultimately achieving effective driving of the IGBT and meeting the power supply requirements of industrial motor drives.

[0109] In a preferred embodiment, the rectifier module 8 is a diode.

[0110] Specifically, the rectifier module 8 uses a diode to rectify the AC signal generated by the secondary side of the isolation transformer 7 into a DC signal.

[0111] In the embodiment of half-wave rectification, the anode of the diode is connected to the first end of the AC signal outputted from the secondary side of the isolation transformer 7, and the cathode of the diode is connected to the first end of the input end of the output filter module 9. At the same time, the second end of the AC signal outputted from the secondary side of the isolation transformer 7 is directly connected to the second end of the input end of the output filter module 9.

[0112] When the AC signal output from the secondary side of the isolation transformer 7 makes the anode potential of the diode higher than the cathode potential (positive half cycle), the diode is turned on, and the current flows to the output filter module 9 through the diode; when the AC signal is in the negative half cycle, the anode potential of the diode is lower than the cathode potential, the diode is cut off, and no current passes through the diode at this time. Only the positive half cycle of the AC signal can reach the output filter module 9 through the diode, realizing half-wave rectification, which can be used in simple application scenarios with low requirements for DC output and low power. The isolation transformer 7 realizes the isolation of the primary and secondary side signals, and realizes different voltage transformation ratios through different turns ratios. The isolation transformer 7 adopts a larger size to achieve a higher withstand voltage value.

[0113] The signal of the specific frequency output by the clock module 4 is adjusted into a PWM signal through the signal processing module 5 to control the on and off of the power driving module 6, thereby changing the current passing through the isolation transformer 7, and finally affecting the output voltage of the isolation transformer 7. The final output voltage is made more stable and reliable through rectification and filtering. The open-loop control method is used to make the circuit have a higher isolation withstand voltage value, and the structure is simple, easy to implement, and low cost.

[0114] In a preferred embodiment, referring to Figure 4 , the output filter module 9 includes,

[0115] An inductor L, a first end of the inductor L is connected to a first output end of the rectifier module 8;

[0116] A second electrolytic capacitor C2 , wherein a first end of the second electrolytic capacitor C2 is connected to the second end of the inductor L, and a second end of the second electrolytic capacitor C2 is connected to the second output end of the rectifier module 8 .

[0117] Specifically, the output filter module 9 includes an inductor L and a second electrolytic capacitor C2. The DC signal rectified by the rectifier module 8 is filtered by the inductor L to reduce its ripple current, and then filtered again by the second electrolytic capacitor C2 to make the output capacitor more stable without excessive ripple.

[0118] In a preferred embodiment, it also includes:

[0119] The power supply module 13 has an input end connected to the input filter module 3, and an output end connected to the clock module 4 and the signal processing module 5, respectively, for converting the voltage of the input power supply and transmitting it to the clock module 4 and the signal processing module 5.

[0120] Specifically, since the voltage value range of the input voltage fluctuates greatly and cannot be applied to the integrated circuit chip, the power supply module 13 is required to supply power to avoid the integrated circuit chip being damaged due to overshoot voltage.

[0121] In a preferred embodiment, the power supply module 13 is a voltage converter (DC / DC converter) that converts the input voltage into a power supply voltage suitable for the integrated circuit chip input, thereby providing a stable power input for the integrated circuit chip.

[0122] Specifically, when the input power supply voltage is 40V, the power supply voltage of the integrated circuit chip is 24V, and the power supply module 13 changes the voltage of 40V to 24V to supply power to the integrated circuit chip.

[0123] The power driving module 6 receives the PWM signal processed by the signal processing module 5, wherein when the PWM signal is in a high-level output signal, the power driving module 6 outputs a first current, and when the PWM signal is in a low-level output signal, the power driving module 6 changes the magnitude of the first current, and the high and low levels in the PWM signal are constantly changing, so that the current flowing through the isolation transformer 7 is also constantly changing, and the constantly changing current causes the magnetic flux passing through the isolation transformer 7 to constantly change, and finally outputs current on the secondary side of the isolation transformer 7, generates a certain voltage to be given to the rear-end load 10, and realizes the control and output of the isolation transformer 7.

[0124] In one embodiment, after receiving the power signal output by the input filter module 3 , the clock module 4 generates an original waveform signal of a specific frequency and waveform (square wave) based on its own circuit structure (oscillation circuit).

[0125] This waveform signal serves as the basic signal source of the entire clock module 4 and provides input signals for subsequent timers, counters and the entire signal processing module 7 .

[0126] The timer uses the waveform signal output by the signal generator as the clock reference to perform timing operations.

[0127] When a 10ms timing cycle is set, the timer will count the pulses of the received waveform signal, and each pulse represents a time unit (depending on the frequency of the signal generator). When the count reaches the number of pulses corresponding to 10ms, the timer will output a timing signal.

[0128] This timing signal can be used to control the start or stop time of the operation in the signal processing module 5, ensuring that each operation in the circuit is performed in a predetermined time sequence, thereby improving the reliability and predictability of the circuit operation.

[0129] The timer counts the waveform signal output by the signal generator to measure time intervals or accumulated time.

[0130] The timer can count the number of cycles of the signal processing module 5 processing the signal. When the count value is reached, a signal is triggered to notify the system to perform an operation, such as adjusting the parameters of the signal processing module 5 or optimizing the output of the power driving module 6.

[0131] The timer provides a control method based on time counting, which helps to adjust the working state of the circuit according to time-related conditions during the operation of the circuit, ensure that the circuit can respond correctly in different working stages, and improve the adaptability and stability of the circuit to various working conditions.

[0132] The base of the transistor is connected to the output of the clock module 4 to receive the waveform signal from the clock module 4. The collector of the transistor is connected to the input of the first integrated circuit chip (analog signal IC chip), and the emitter is grounded (or connected to a suitable bias circuit, depending on the specific circuit design).

[0133] When the waveform signal from clock module 4 is input to the base of the transistor:

[0134] Taking BJT as an example, when the voltage between the base and the emitter changes, it will cause the collector current to change, thereby amplifying the current of the input waveform signal.

[0135] The transistor can also be used as an electronic switch to control the on and off of the signal according to the high and low levels of the input signal and perform preliminary shaping of the input waveform.

[0136] The analog signal IC chip first filters the received signal, and removes high-frequency noise or unnecessary frequency components in the input signal through the internal filtering circuit, making the signal purer.

[0137] Then, the signal is precisely linearly amplified according to a certain gain multiple, and the amplitude of the signal is adjusted to make the signal waveform more regular and the amplitude more in line with the requirements of subsequent digital signal processing.

[0138] In addition, analog signal IC chips can also modulate signals, such as changing parameters such as the frequency, phase or amplitude of the signal, to transform the analog signal to the final desired stable and appropriate waveform state, providing high-quality analog input signals for subsequent digital signal IC chips to accurately perform analog-to-digital conversion and other operations.

[0139] The input end of the second integrated circuit chip (digital signal IC chip) is connected to the output end of the analog signal IC chip to receive the processed analog signal. After being processed by the internal digital circuit (such as analog-to-digital converter, logic circuit, etc.), a pulse width modulation signal is output from its output end and sent to the power driving module 6.

[0140] The digital signal IC chip first converts the received analog signal into a digital signal through the internal analog-to-digital converter (ADC).

[0141] The comparator compares the digital signal levels at different times and generates the corresponding digital output signal according to the pre-set algorithm and logic rules. Finally, after encoding and modulation, the digital output signal is converted into a PWM signal.

[0142] The high-voltage IGBT-driven power supply circuit of the present invention has a higher isolation withstand voltage value, which can meet the isolation of the front-stage and rear-stage circuits under high voltage conditions. The open-loop control circuit of the present invention can not only stabilize the voltage value of the output voltage within a certain range and provide a relatively stable voltage value for the IGBT drive unit, but also has a low manufacturing cost, which is conducive to the production and promotion of the product.

[0143] The above description is only a preferred embodiment of the present invention, and does not limit the implementation mode and protection scope of the present invention. For those skilled in the art, it should be aware that all solutions obtained by equivalent substitutions and obvious changes made using the description and illustrations of the present invention should be included in the protection scope of the present invention.

Claims

1. A power supply circuit for driving an insulated gate bipolar transistor, characterized in that: include, An input filter module, wherein an input end of the input filter module is connected to an input power supply; A clock module, connected to the output end of the input filter module, for outputting a waveform signal; A signal processing module, connected to the output end of the clock module, for processing the waveform state of the waveform signal and outputting a pulse width modulation signal; A power driving module, connected to the output end of the signal processing module, receives the pulse width modulation signal, and is turned off and on under the action of the pulse width modulation signal; An isolation transformer, wherein the primary side of the isolation transformer is connected to the output end of the power driving module; A rectifier module, connected to the secondary side of the isolation transformer, for rectifying the alternating current output by the isolation transformer into direct current; The output filter module is connected to the output end of the rectifier module.

2. The power supply circuit for driving an insulated gate bipolar transistor according to claim 1, characterized in that: The input filtering module includes: A varistor, the varistor is connected in parallel with the input power supply; A first electrolytic capacitor is connected in parallel with the varistor.

3. The power supply circuit for driving an insulated gate bipolar transistor according to claim 1, characterized in that: The clock module comprises: A signal generator, connected to the output end of the input filter module, for emitting the waveform signal; A timer, connected to the output end of the signal generator, for receiving the waveform signal and timing; A timer, connected to the output end of the signal generator, for counting the waveform signal; A crystal oscillator is connected to the signal generator and is used to drive the signal generator to emit the waveform signal.

4. The power supply circuit for driving an insulated gate bipolar transistor according to claim 1, characterized in that: The magnetic core of the isolation transformer is made of ferrite material, the primary winding and the secondary winding of the isolation transformer are both wound with multi-layer insulating enameled wire, and an insulating layer is provided between the primary winding and the secondary winding.

5. The power supply circuit for driving an insulated gate bipolar transistor according to claim 1, characterized in that: The signal processing module comprises: A transistor, the base of which is connected to the output end of the clock module, and is used to amplify the waveform signal to obtain an amplified signal; A first integrated circuit chip, wherein the input end of the first integrated circuit chip is connected to the collector of the transistor, and is used to receive the amplified signal and perform filtering and signal amplification processing to output an analog signal; A second integrated circuit chip, wherein the input end of the second integrated circuit chip is connected to the output end of the first integrated circuit chip, and is used for receiving and converting the analog signal into the pulse width modulation signal and then outputting it.

6. The power supply circuit for driving an insulated gate bipolar transistor according to claim 5, characterized in that: The first integrated circuit chip is an analog signal integrated circuit chip, and the second integrated circuit chip is a digital signal integrated circuit chip.

7. The power supply circuit for driving an insulated gate bipolar transistor according to claim 1, characterized in that: The rectifier module is a diode.

8. The power supply circuit for driving an insulated gate bipolar transistor according to claim 1, characterized in that: The output filtering module includes: an inductor, a first end of the inductor being connected to a first output end of the rectifier module; A second electrolytic capacitor, wherein a first end of the second electrolytic capacitor is connected to the second end of the inductor, and a second end of the second electrolytic capacitor is connected to the second output end of the rectifier module.

9. The power supply circuit for driving an insulated gate bipolar transistor according to claim 1, characterized in that: Also includes, A power supply module, wherein the input end of the power supply module is connected to the input filter module, and the output end of the power supply module is respectively connected to the clock module and the signal processing module, and is used to convert the voltage of the input power supply and transmit it to the clock module and the signal processing module.

10. The power supply circuit for driving an insulated gate bipolar transistor according to claim 9, characterized in that: The power supply module is a voltage converter.

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