High-voltage pulse power supply system capable of regulating voltage through frequency conversion and design method

Abstract

The invention discloses a high-voltage pulse power supply system through frequency conversion voltage regulation and a design method, and belongs to the technical field of pulse power supplies, the high-voltage pulse power supply system comprises a boosting module and a pulse generation module, in the boosting module, a single-chip microcomputer generates an alternating square wave signal with a certain frequency and inputs the alternating square wave signal into a driving circuit, and a switch of an MOS tube is indirectly controlled through an optocoupler and a device in the single-chip microcomputer; two paths of 12V square wave voltages are generated and applied to the LCC boost circuit, the input 12V high-frequency low-voltage electricity is converted into high-frequency high-voltage electricity, and the generated high-frequency high-voltage electricity is subjected to voltage doubling rectification through the C-W third-order six-time voltage doubling circuit and is output to the voltage division circuit; the frequency regulation and control circuit can be adjusted to change the frequency of the square wave signal generated by the single chip microcomputer so as to control the amplitude of the output voltage; and meanwhile, the voltage division circuit divides the finally generated high voltage to the main control circuit to form closed-loop regulation on the voltage. And the generated high-frequency high-voltage electricity is input into the pulse generation module to generate pulses. The device is simple in structure, adjustable in output voltage and high in transformer conversion efficiency.

Description

Technical Field

[0001] The present invention belongs to the technical field of pulse power supply, and in particular relates to a high-voltage pulse power supply system and a design method thereof by frequency conversion and voltage regulation. Background Art

[0002] The high-voltage pulse helium ionization detector is a highly sensitive broad-spectrum sensor that responds to almost all gas molecules except neon. Therefore, this detector is widely used in high-purity gas analysis (impurity gases such as H2, O2, N2, CO, CH4, etc.), fault diagnosis of insulating oil transformers, and fault diagnosis and analysis of SF6-insulated transformers. The high-voltage discharge electrode in the discharge area of ​​this highly sensitive broad-spectrum helium ionization detector needs to be connected to a high-voltage pulse power supply to form an ionization source to ionize the high-purity helium to form metastable helium ions He with high ionization energy. Atom (ionization energy 19.8 eV).

[0003] The existing pulse power supply provided by the helium ionization detector cannot flexibly adjust the output voltage, the adjustable frequency range is not wide enough, and the voltage accuracy is not enough. Therefore, during the test, the helium ionization detector will have problems such as insufficient ionization in normal operation. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a high-voltage pulse power supply system and design method for variable frequency voltage regulation, using MOSFET as a power switch device, using a middle tap transformer, constructing a symmetrical boost structure with two upper and lower paths, using an LCC circuit, so that the circuit can adjust the voltage amplitude by adjusting the frequency of the signal, and finally using a pulse generating circuit to convert the generated high voltage into a high-voltage pulse voltage. The pulse power supply system of the present invention has the following characteristics: (1) the generated pulse voltage frequency is adjustable at 2-10k, (2) the voltage amplitude range is 1000-2500V, and (3) the voltage amplitude is closed-loop regulated with high accuracy.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] A high-voltage pulse power supply system with variable frequency voltage regulation includes a boost module and a pulse generating module. The DC high voltage voltage generated by the boost module is connected to the pulse generating module to form a pulse. The boost module includes a driving circuit, a boost circuit, a frequency regulating circuit, a voltage doubling circuit and a voltage dividing feedback circuit; wherein,

[0007] The driving circuit is used to provide an alternating voltage signal to the LCC boost circuit under the control instruction of the main control circuit;

[0008] The LCC boost circuit is used to regulate the high voltage generated by the transformer using the resonant characteristics of the LCC circuit;

[0009] The frequency adjustment circuit is used to adjust the frequency of the pulse signal generated by the main control circuit, thereby changing the frequency of the signal applied to the drive circuit;

[0010] The voltage doubling circuit is used to rectify and double the high-frequency AC voltage generated by the LCC boost circuit into a DC high-voltage voltage with an amplitude six times that of the high-frequency AC voltage and input it into the pulse generating module;

[0011] The voltage-dividing feedback circuit is used to divide the generated DC high voltage into a voltage range detectable by the main control circuit, detect voltage changes in real time, and provide an adjustment reference signal for the frequency adjustment circuit.

[0012] On the other hand, the present invention provides a method for designing a high-voltage pulse power supply system by frequency conversion and voltage regulation, the method comprising:

[0013] The driving circuit provides an alternating voltage signal to the LCC boost circuit under the control instruction of the main control circuit; wherein the main control circuit is also connected to a frequency adjustment circuit for adjusting the frequency of the pulse signal generated by the main control circuit, thereby changing the signal frequency applied to the driving circuit;

[0014] The LCC boost circuit receives the alternating voltage signal and regulates the high-frequency AC voltage generated by the transformer in combination with the resonance characteristics of the LCC circuit;

[0015] The high-frequency AC voltage generated by the LCC boost circuit is rectified and doubled by a voltage doubling circuit into a DC voltage 6 times the amplitude of the high-frequency AC voltage, and then input into a pulse generating module to form a pulse;

[0016] The voltage-dividing feedback circuit is used to divide the generated DC high voltage into a voltage range detectable by the main control circuit, and the voltage change is detected in real time to provide an adjustment reference signal for the frequency adjustment circuit.

[0017] The beneficial effects of the present invention are:

[0018] Compared with the traditional pulse power supply, the present invention adds a voltage feedback system, which can adjust the voltage in real time, thereby further controlling the accuracy of the power supply and improving the stability of the pulse power supply output; the structure is relatively simple, the chip used is inexpensive, and the cost is low; the pulse width, frequency, and output voltage are adjustable; the transformer has high conversion efficiency and long service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic circuit diagram of a boost module of a high-voltage pulse power supply system of the present invention that uses variable frequency voltage regulation;

[0020] Figure 2The present invention is a circuit schematic diagram of a pulse generation module of a high-voltage pulse power supply system that uses variable frequency voltage regulation. DETAILED DESCRIPTION

[0021] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0022] The present invention provides a high-voltage pulse power supply system through variable frequency voltage regulation, the system includes a boost module and a pulse generating module, wherein the boost module includes a driving circuit, a boost circuit, a frequency regulating circuit, a voltage doubling circuit and a voltage dividing feedback circuit. The high-voltage voltage HIGH_V_OUT generated by the boost module is connected to the HV end of the pulse generating module to provide high voltage, and the GND is interconnected. After receiving the high voltage, the pulse generating module controls the MOS tube to be alternately turned on through the gate driving chip Logic1 to form a pulse.

[0023] like Figure 1 As shown, it is the schematic diagram of the boost module of the pulse power supply system. The module improves the traditional half-bridge inverter circuit and adds a feedback loop, etc. Specifically, it includes a drive circuit 1; an LCC boost circuit 2; a frequency adjustment circuit 3; a C-W 3-stage 6-fold voltage multiplier circuit 4; and a voltage divider feedback circuit 5.

[0024] The drive circuit 1 is used to provide an alternating voltage signal to the primary side of the transformer T1 (ie, the right end of the transformer T1 ) of the LCC boost circuit 2 under the control instruction of the main control circuit.

[0025] The LCC boost circuit 2 is used to convert the low voltage on the primary side of the transformer T1 into a high voltage on the secondary side, and at the same time utilizes the resonance characteristics of the LCC circuit, that is, the frequency of the voltage, to regulate the high voltage generated on the secondary side.

[0026] The frequency adjustment circuit 3 is used to adjust the frequency of the pulse signal generated by the main control circuit, that is, when the main control chip of the main control circuit detects the change of the potentiometer voltage, it adjusts the frequency of the generated pulse signal, thereby changing the signal frequency applied to the drive circuit 1, thereby adjusting the voltage of the LCC boost circuit 2.

[0027] The C-W 3-stage 6-fold voltage multiplier circuit 4 is used to rectify the high-frequency AC voltage generated by the secondary side of the transformer T1 and double the voltage into a DC voltage with an amplitude 6 times that of the high-frequency AC voltage.

[0028] The voltage-dividing feedback circuit 5 is used to divide the generated DC high voltage into a voltage range detectable by the main control circuit, and provide it to the voltage detection pin to detect voltage changes in real time.

[0029] Specifically, the drive circuit 1 includes the following circuit structure: for the boost module, the two signals from the main control circuit (not a characteristic circuit of this system, not shown in the figure) are input to the No. 1 pin of the optocoupler and chip U357-1 and U357-2, and the No. 2 pin is connected to the resistors DR29 and DR31 respectively, and the other ends of the resistors DR29 and DR31 are grounded. The left end of the optocoupler and chip is a phototransistor, the No. 4 pin is connected to the voltage of 6V-8V, the No. 3 pin is connected to the resistors DR20 and DR21, and the other ends of the resistors DR20 and DR21 are grounded. At the same time, the No. 3 pin of the optocoupler and chip U357-1 and U357-2 is also connected to the gate pin (i.e., No. 1 pin) of the MOS tubes Q11 and Q12, the source electrodes of the MOS tubes Q11 and Q12 are respectively connected to the No. 3 pin and the No. 5 pin of the transformer T1, and the drain electrodes of the MOS tubes Q11 and Q12 are grounded. This circuit controls two MOS tubes to be turned on alternately to generate an alternating voltage in the transformer T1 of the LCC boost circuit 2.

[0030] The LCC boost circuit 2 includes the following circuit structure: the primary coil of the transformer T1 is a primary coil, and the primary coil includes three pins, wherein the first capacitor is connected between the first and second pins, the second capacitor is connected between the second and third pins, and the second pin is also connected to the inductor, the third capacitor, and the 12V voltage in sequence; the secondary side of the transformer is a secondary coil, one end pin of the secondary coil is grounded, and the other end pin is connected to the fourth capacitor. Specifically, the capacitor PCp2 is connected between the No. 3 and No. 4 pins of the primary coil, the capacitor PCp1 is connected between the No. 5 and No. 4 pins, and the No. 4 pin is also connected to the inductor Y_L, the other end of the inductor Y_L is connected to the capacitor PCs, and the other end of the capacitor PCs is connected to the 12V voltage. The secondary side of the transformer T1 is a secondary coil, the No. 2 pin of the secondary coil is grounded, and the No. 1 pin is connected to the capacitor PC_1. The present invention adopts a transformer with a primary middle tap and makes it form an upper and lower symmetrical LCC structure, which can adjust the voltage amplitude by frequency conversion, thereby adjusting the output voltage amplitude. At the same time, the symmetrical structure can make the upper and lower coils form alternating current, thereby improving voltage efficiency. The generated voltage is input to the C-W3-stage 6-fold voltage multiplier circuit 4.

[0031] The frequency adjustment circuit 3 includes the following circuit structure: the No. 1 pin of the potentiometer ROT is grounded, the No. 3 pin is connected to VDD, and the potential of the No. 2 pin is output to the main control circuit. The voltage of the potentiometer ROT changes linearly. After adjusting the voltage of the potentiometer ROT, the main control chip of the main control circuit collects the voltage change and outputs the signal frequency to the drive circuit 1 according to the corresponding change of the program design, thereby adjusting the voltage.

[0032] The C-W 3-stage 6-fold voltage multiplier circuit 4 includes the following circuit structure: one end of the capacitor PC_1 is connected to the No. 1 pin of the transformer T1, and the other end is connected to the anode of the diode D_1 and the cathode of the diode D_2. The capacitor PC_2 is connected between the cathode of the diode D_1 and the anode of the diode D_2. Meanwhile, the cathode of the diode D_1 is grounded, and the other end of the capacitor PC_2 is grounded. The capacitor PC_3 is connected between the cathode of the diode D_2 and the anode of the diode D_5, and the anode of the diode D_2 is connected to the cathode of the diode D_5. The anode of diode D_5 is connected to the cathode of diode D_6, and capacitor PC_4 is connected between the cathode of diode D_5 and the anode of diode D_6; the anode of diode D_6 is connected to the cathode of diode D_7, and capacitor PC_5 is connected between the cathode of diode D_6 and the anode of diode D_7; the anode of diode D_7 is connected to the cathode of diode D_8, and capacitor PC_6 is connected between the cathode of diode D_7 and the anode of diode D_8; this voltage doubling circuit 4 rectifies the generated high-voltage and high-frequency alternating current into high-voltage direct current, and the amplitude of the high-voltage direct current voltage is 6 times the amplitude of the high-voltage alternating current generated by the secondary side of transformer T1.

[0033] The voltage-dividing feedback circuit 5 includes a circuit for receiving the final output voltage of the voltage-doubling circuit, and is connected to the first voltage-dividing resistor unit and the second voltage-dividing resistor unit in sequence. One end of the second voltage-dividing resistor unit is connected to the regulating resistor, and the other end is input to the main control circuit as a voltage signal. The main control chip of the main control circuit collects the voltage signal and converts it into an actual voltage, and changes the output voltage amplitude to the required voltage by adjusting the frequency adjustment circuit. Specifically, it can be the following circuit structure: the final output voltage end (i.e., the anode of the diode D_8 and one end of the capacitor PC_6) is connected to one end of the voltage-dividing resistors DFR3 and DFR4, and the other ends of the resistors DFR3 and DFR4 are connected (i.e., in parallel), and then connected to the parallel resistors DFR2 and DFR5, and the other ends of the resistors DFR2 and DFR5 are connected to the resistor DFR1, and the other end of the resistor DFR1 is grounded. At the same time, the left side of the resistor DFR1 is input to the main control circuit as a voltage signal. At this time, the main control chip collects the voltage data and converts it into an actual voltage according to the linear relationship, and changes the output voltage amplitude to the required voltage by adjusting the frequency adjustment circuit 3.

[0034] The high-voltage pulse power supply developed by the present invention adopts a half-bridge inverter circuit as a boost circuit, and uses a MOS tube and a transformer to perform a boost process. The schematic diagram is as follows: Figure 1As shown, the main control chip is used to control the generation of two PWM wave signals IO1 and IO2, which are transmitted to the optical coupling devices U357-1 and U357-2 to boost the signal and isolate the boost circuit from the main control circuit. The generated signal causes the MOS tubes Q11 and Q12 to conduct alternately, thereby generating a changing voltage on the primary coil on the right side of the transformer T1. Both parts of the primary coil use LCC circuits. When working normally, the power supply will work in a resonant state. At this time, the change in frequency has a great impact on the system output. Therefore, when the frequency of the signal generated by the main control chip changes, the voltage output by the secondary side will change, allowing the circuit to perform frequency modulation and voltage regulation. The secondary circuit uses a CW structure 3rd order 6 times voltage multiplier circuit. Here, Um is used to represent the peak value of the high-voltage side output voltage. After passing through the CW structure 3rd order 6 times voltage multiplier circuit, the voltage on the capacitor PC_6 is 6Um. A transformer consisting of a suitable magnetic core and winding can generate a voltage of 1000-2500V.

[0035] On the other hand, the present invention provides a method for designing a high-voltage pulse power supply system by frequency conversion and voltage regulation, the method comprising:

[0036] The driving circuit provides an alternating voltage signal to the LCC boost circuit under the control instruction of the main control circuit; wherein the main control circuit is also connected to a frequency adjustment circuit for adjusting the frequency of the pulse signal generated by the main control circuit, thereby changing the signal frequency applied to the driving circuit;

[0037] The LCC boost circuit receives the alternating voltage signal and regulates the high-frequency AC voltage generated by the transformer in combination with the resonance characteristics of the LCC circuit;

[0038] The high-frequency AC voltage generated by the LCC boost circuit is rectified and doubled by a voltage doubling circuit into a DC voltage 6 times the amplitude of the high-frequency AC voltage, and then input into a pulse generating module to form a pulse;

[0039] The voltage-dividing feedback circuit is used to divide the generated DC high voltage into a voltage range detectable by the main control circuit, and the voltage change is detected in real time to provide an adjustment reference signal for the frequency adjustment circuit.

[0040] like Figure 1 As shown, the present invention adopts voltage-dividing feedback for the output high voltage, utilizes the voltage-dividing effect of the resistor, transforms the high voltage into the range that the voltage acquisition chip can acquire, and then the acquisition chip feeds back to the main control chip to adjust the generated signal frequency, completing the closed loop of voltage regulation to ensure the accuracy of the output voltage. By using the voltage regulation of the potentiometer, the main control chip will collect different voltages, and adjust the output signal frequency by the change of the voltage. Within a certain preset frequency range, the voltage generated by the secondary side is positively correlated with the signal frequency, thereby adjusting the output voltage. Therefore, the output voltage can be controlled by controlling the frequency of the square wave signal through the potentiometer.

[0041] The high voltage generated by the boost module is input to Figure 2 In the pulse generation module shown, the No. 1 pin of the chip Logic1 is connected to 12V, the No. 4 pin is grounded, and the No. 2 pin is connected to the square wave signal from the main control circuit. Finally, the No. 7 and No. 6 pins of the chip Logic1 will generate alternating signals, which are connected to the No. 1 pins of the transistors Q5 and Q6 respectively. At the same time, the No. 2 pin of the transistor Q5 is connected to the high voltage, the No. 3 pin of the transistor Q5 is connected to the No. 2 pin of the transistor Q6, and the No. 3 pin of the transistor Q6 is grounded. When the No. 7 pin HO is high voltage, the No. 6 pin LO is low voltage. At this time, the MOS tube Q5 is turned on, Q6 is turned off, and OUT is high voltage. When the No. 7 pin is HO and low voltage, the No. 6 pin LO is high voltage. At this time, the MOS tube Q5 is turned off, Q6 is turned on, and OUT is low voltage.

[0042] The gate driver chip is used to drive the two MOS tubes of the pulse generation module to turn on alternately, ultimately generating a pulse voltage of 1000-2500V. At the same time, the duty cycle of the output pulse voltage can be changed by adjusting the input signal.

[0043] In summary, the high voltage pulse power supply system is characterized by:

[0044] 1) The primary coil of the transformer, i.e. Figure 1 The upper and lower parts of the coil on the right side of the transformer T1 both use LCC circuits. The power supply works in a resonant state. The change in frequency has a great impact on the system output, allowing the circuit to perform frequency and voltage modulation.

[0045] 2) Two optocouplers and devices are used to drive the MOS tube. The structure is symmetrical. The errors generated when the two signals transmitted by the control chip are converted by the driver chip are consistent and can be offset to ensure the phase difference of the two signals. At the same time, the boost circuit and the control circuit can be isolated to prevent the control circuit from being burned.

[0046] 3) Select a transformer with appropriate wire diameter so that its output current can reach the current required for ionization, reduce transformer core loss, and improve the overall output efficiency of the power supply.

[0047] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A high-voltage pulse power supply system with variable frequency voltage regulation, characterized in that: It includes a boost module and a pulse generation module. The DC high voltage generated by the boost module is connected to the pulse generation module to form a pulse. The boost module includes a drive circuit, a boost circuit, a frequency adjustment circuit, a voltage doubling circuit and a voltage divider feedback circuit; wherein, The driving circuit is used to provide an alternating voltage signal to the LCC boost circuit under the control instruction of the main control circuit; The LCC boost circuit is used to control the high-frequency AC voltage generated by the transformer by utilizing the resonance characteristics of the LCC circuit; The frequency adjustment circuit is used to adjust the frequency of the pulse signal generated by the main control circuit, thereby changing the frequency of the signal applied to the drive circuit; The voltage doubling circuit is used to rectify and double the high-frequency AC voltage generated by the LCC boost circuit into a DC high-voltage voltage with an amplitude six times that of the high-frequency AC voltage and input it into the pulse generating module; The voltage-dividing feedback circuit is used to divide the generated DC high voltage into a voltage range detectable by the main control circuit, detect voltage changes in real time, and provide an adjustment reference signal for the frequency adjustment circuit.

2. A high-voltage pulse power supply system with variable frequency voltage regulation according to claim 1, characterized in that: The driving circuit uses two optical couplers and devices to drive the MOS tube, and the structure is symmetrical.

3. A high-voltage pulse power supply system with variable frequency voltage regulation according to claim 2, characterized in that: The two signals from the main control circuit are respectively input to the two optocouplers and the chip of the driving circuit, the two optocouplers and the chip are respectively connected to the gate pins of the two MOS tubes, the sources of the two MOS tubes are respectively connected to the transformer of the LCC boost circuit, when the two MOS tubes are alternately turned on, the transformer of the LCC boost circuit generates an alternating voltage.

4. A high-voltage pulse power supply system with variable frequency voltage regulation according to claim 1, characterized in that: The primary coil of the transformer of the LCC boost circuit is a primary coil, and the primary coil includes three pins, wherein a first capacitor is connected between the first and second pins, a second capacitor is connected between the second and third pins, and the second pin is also connected to an inductor, a third capacitor, and a 12V voltage in sequence; the secondary side of the transformer is a secondary coil, one end pin of the secondary coil is grounded, and the other end pin is connected to a fourth capacitor.

5. A high-voltage pulse power supply system with variable frequency voltage regulation according to claim 1, characterized in that: The frequency adjustment circuit includes a potentiometer, the voltage of the potentiometer changes linearly, and the main control chip of the main control circuit changes the frequencies of two signals output to the drive circuit according to the voltage linear change law, thereby adjusting the voltage of the LCC boost circuit.

6. A high-voltage pulse power supply system with variable frequency voltage regulation according to claim 1, characterized in that: The voltage doubler circuit is a C-W 3-stage 6-fold voltage doubler circuit, which includes a plurality of alternately connected capacitors and diodes, and rectifies the high-voltage and high-frequency AC power generated by the secondary side of the transformer of the LCC boost circuit into a high-voltage DC voltage with an amplitude 6 times that of the high-voltage and high-frequency AC power.

7. A high-voltage pulse power supply system with variable frequency voltage regulation according to claim 1, characterized in that: The voltage divider feedback circuit 5 receives the final output voltage of the voltage doubling circuit and is connected to the first voltage divider resistor unit and the second voltage divider resistor unit in sequence. One end of the second voltage divider resistor unit is connected to the adjustment resistor, and the other end is input to the main control circuit as a voltage signal. The main control chip of the main control circuit collects the voltage signal and converts it into an actual voltage, and changes the output voltage amplitude to the required voltage by adjusting the frequency adjustment circuit.

8. A high-voltage pulse power supply system with variable frequency voltage regulation according to claim 7, characterized in that: The first voltage-dividing resistor unit includes two resistors connected in parallel, and the second voltage-dividing resistor unit includes two resistors connected in parallel.

9. A high-voltage pulse power supply system with variable frequency voltage regulation according to claim 1, characterized in that: The pulse generating module comprises a gate driving chip, the gate driving chip receives a square wave signal generated by a main control circuit, and utilizes the gate driving chip to drive two MOS tubes of the pulse generating module to be turned on alternately.

10. A high-voltage pulse power supply system with variable frequency voltage regulation according to claim 1, characterized in that: Within a preset frequency range, the voltage generated by the secondary side of the transformer of the LCC boost circuit is positively correlated with the signal frequency.

11. A method for designing a high-voltage pulse power supply system by frequency conversion and voltage regulation, characterized in that: The method comprises: The driving circuit provides an alternating voltage signal to the LCC boost circuit under the control instruction of the main control circuit; wherein the main control circuit is also connected to a frequency adjustment circuit for adjusting the frequency of the pulse signal generated by the main control circuit, thereby changing the signal frequency applied to the driving circuit; The LCC boost circuit receives the alternating voltage signal and regulates the high-frequency AC voltage generated by the transformer in combination with the resonance characteristics of the LCC circuit; The high-frequency AC voltage generated by the LCC boost circuit is rectified and doubled by a voltage doubling circuit into a DC voltage 6 times the amplitude of the high-frequency AC voltage, and then input into a pulse generating module to form a pulse; The voltage-dividing feedback circuit is used to divide the generated DC high voltage into a voltage range detectable by the main control circuit, and the voltage change is detected in real time to provide an adjustment reference signal for the frequency adjustment circuit.

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