CN206195628U - High voltage direct current genera tor based on series resonance - Google Patents

Abstract

The utility model discloses a DC high voltage generator based on series resonance, which comprises an EMI power supply filter module, a PFC module, a bridge rectification filter module, a full bridge inverter module, a series resonance boost module, and a rectification and voltage doubling module connected in sequence , the voltage on the capacitor on the output side of the full-bridge inverter module and the current on the inductor, the current on the inductor on the output side of the series resonant boost module, and the output side of the rectifier and doubler module are all connected to the voltage and current conditioning circuit, and the voltage and current conditioning circuit is connected to the DSP The processing unit is connected, and the DSP processing unit is respectively connected with a protection circuit, a driving circuit, and an STM display control circuit, and the STM display control circuit is respectively connected with an LCD display module and a key control module, and the driving circuit is connected with the output side of the bridge rectifier filter module. The output voltage of the DC high-voltage generator of the utility model is continuously adjustable from 0 to 300 kV, has smaller volume, lighter weight, larger capacity, easy operation, and is convenient for on-site withstand voltage tests.

Description

A DC High Voltage Generator Based on Series Resonance

technical field

The utility model belongs to the technical field of power equipment, in particular to a DC high voltage generator based on series resonance.

Background technique

In order to ensure the safety and reliability of power system operation, power equipment must be subjected to withstand voltage tests before being put into operation and during operation. DC high-voltage generator is one of the main equipment for high-voltage test of electric power equipment. It is mainly suitable for the power department of electric power department, industrial and mining, metallurgy, steel and other enterprises to conduct high-voltage electrical equipment such as zinc oxide arrester, power cable, transformer, generator, etc. DC withstand voltage test. At present, the principle of the DC high-voltage generator is mainly to obtain high-voltage DC power after rectifying, inverting, boosting the voltage of the transformer, and rectifying the voltage of 220V AC. However, as the capacity of the tested product increases, the equivalent capacitance of the tested product also increases. When the high voltage level and the equivalent capacitance of the tested product are large, the capacity and volume of the test equipment required are large. Therefore, it is difficult for traditional test equipment (such as transformers) to meet the requirements of on-site withstand voltage tests in terms of capacity, volume, and weight.

Utility model content

The purpose of this utility model is to provide a DC high-voltage generator based on series resonance, which solves the problem that the capacity and volume of the existing DC high-voltage generator cannot meet the requirements of the on-site voltage withstand test when the capacity of the tested product is large.

The technical solution adopted by the utility model is, a DC high voltage generator based on series resonance, including an EMI power supply filter module, a PFC module, a bridge rectifier filter module, a full bridge inverter module, and a series resonance boost module connected in sequence , Rectifier voltage doubler module, the voltage on the capacitor and current on the inductor at the output side of the full-bridge inverter module, the current on the inductor at the output side of the series resonant boost module, and the output side of the rectifier voltage doubler module are all connected to the voltage and current conditioning circuit, the voltage The current conditioning circuit is connected with the DSP processing unit, and the DSP processing unit is respectively connected with a protection circuit, a drive circuit, and an STM display control circuit, and the STM display control circuit is respectively connected with an LCD display module, a key control module, a drive circuit and a bridge rectifier filter module. output side connection.

The utility model is also characterized in that:

The STM display control circuit is also connected with a serial port printing module.

The IGBT of the full-bridge inverter module is equipped with a cooling fin, and a temperature sensor is installed on the cooling fin, and the temperature sensor is connected with the DSP processing unit.

The full-bridge inverter module adopts the SPWM modulation method of unipolar frequency multiplication.

The beneficial effects of the utility model are: the output voltage of the DC high-voltage generator based on series resonance is continuously adjustable from 0 to 300kV, the utility model is smaller in size, lighter in weight, larger in capacity, easy to operate, and complete in function, which is convenient for operators to carry out On-site pressure test, easy to use in the field.

Description of drawings

Fig. 1 is the structural representation of the utility model DC high voltage generator;

Fig. 2 is a series resonance schematic diagram and a feedback control diagram in the utility model DC high voltage generator;

Fig. 3 is a structural block diagram of double closed-loop feedback control in the DC high voltage generator of the present invention;

Fig. 4 is a diagram of the frequency sweep boosting method in the DC high voltage generator of the present invention.

In the figure, 1. EMI power filter module, 2. PFC module, 3. Bridge rectifier filter module, 4. Full bridge inverter module, 5. Series resonant boost module, 6. Rectifier voltage doubler module, 7. Voltage and current Conditioning circuit, 8. DSP processing unit, 9. Protection circuit, 10. Drive circuit, 11. STM display control circuit, 12. LCD display module, 13. Serial port printing module, 14. Key control module.

detailed description

The utility model will be described in detail below in conjunction with the accompanying drawings and specific embodiments.

The utility model is a DC high voltage generator based on series resonance. The structure is shown in Fig. 1, including an EMI power supply filter module 1, a PFC module 2, a bridge rectifier filter module 3, a full bridge inverter module 4, and a series connection The resonant boost module 5, the rectifier voltage doubler module 6, the full-bridge inverter module 4 adopts the SPWM modulation mode of unipolar frequency multiplication, the voltage on the capacitor on the output side of the full-bridge inverter module 4 and the current on the inductor, the series resonance rises The current on the inductance on the output side of the voltage module 5 and the output side of the rectification and voltage doubling module 6 are all connected to the voltage and current conditioning circuit 7, and the voltage and current conditioning circuit 7 is connected with the DSP processing unit 8, and the DSP processing unit 8 is respectively connected with a protection circuit 9, a drive Circuit 10, STM display control circuit 11, STM display control circuit 11 is respectively connected with LCD display module 12, serial port printing module 13, key control module 14, drive circuit 10 is connected with the output side of bridge rectifier filter module 3.

The IGBT of the full-bridge inverter module 4 is equipped with a cooling fin, and a temperature sensor is installed on the cooling fin, and the temperature sensor is connected with the DSP processing unit 8 .

When in use, first connect the 50Hz, AC220V AC power to the EMI power filter module 1, and then connect to the PFC module 2. The purpose is to isolate the power grid from the DC high voltage source and improve the power factor of the DC high voltage source; Single-phase bridge rectification filter module 3, which converts AC220V AC power into about 300V DC voltage; bridge rectifier filter module 3 is connected with IGBT full-bridge inverter module 4, and converts the rectified 300V DC power into AC power; full-bridge inverter Module 4 is connected to LC series resonant boost module 5. By adjusting the frequency of the output voltage of the inverter bridge, the LC series circuit resonates, thereby outputting an AC voltage with a maximum value of 50kV on the capacitance or inductance of the circuit; the series resonant boost module 5 The rectification and voltage doubling module 6 is connected afterwards, and the large voltage obtained by the series resonant boosting module 5 is rectified, filtered and further boosted to obtain the desired output DC high voltage (maximum value is 300kV). The voltage on the capacitor on the output side of the full-bridge inverter module 4 and the current on the inductor, the current on the inductor on the output side of the series resonant step-up module 5, and the output side of the rectification and doubler module 6 are all connected to the voltage and current conditioning circuit 7, and the voltage and current conditioning The circuit 7 sends the detected voltage and current signals to the AD acquisition chip after being processed by the operational amplifier circuit, and then sends them to the DSP processing unit 8 after AD conversion. The DSP processing unit 8 is respectively connected with the protection circuit 9, the driving circuit 10, and the STM display The control circuit 11 and the STM display control circuit 11 are respectively connected with an LCD display module 12 , a serial port printing module 13 , and a key control module 14 , and the driving circuit 10 is connected with the output side of the bridge rectification and filtering module 3 .

The full-bridge inverter module 4 in the DC high-voltage generator based on series resonance of the utility model adopts the SPWM modulation method of unipolar frequency multiplication to realize the control of the power switching device, so that the output voltage frequency and amplitude of the inverter side can be independent Adjustment, the amplitude and frequency of the output voltage of the full-bridge inverter module 4 can be changed by controlling the frequency and amplitude of the modulation wave, thereby changing the output voltage; The output side of the inverter gets an output voltage pulse signal twice the carrier frequency, which increases the harmonic order and reduces the harmonic content, so that the ripple of the output voltage is further reduced.

The IGBT of the full-bridge inverter module 4 is equipped with a heat sink, the heat sink is equipped with a temperature sensor, the temperature sensor is connected to the DSP processing unit 8, and the temperature sensor is used to collect the temperature of the heat sink and transmit it to the DSP processing unit 8 to adjust the speed of the fan. When the temperature is higher than a certain threshold, the PWM wave is immediately turned off for cooling the IGBT. Installing a temperature sensor on the heat sink of the IGBT can realize real-time monitoring of the temperature of the switch tube and improve the reliability of the system.

The series resonance step-up module 5 in the DC high voltage generator based on the series resonance of the utility model does not use an intermediate frequency or high frequency transformer, but uses the principle of RLC series resonance to boost the voltage. The structure diagram is shown in Figure 2, and the series resonance The boost module 5 specifically includes an LC filter circuit, an excitation transformer boost circuit and an RLC series resonant circuit. When the 5 loops of the series resonant boost module resonate, the voltage Q (quality factor, generally 20-80) on the capacitance or inductance of the resonance loop is twice the input voltage, so that a larger output voltage can be obtained with a smaller input power. The series resonant step-up module 5 uses an excitation transformer with a fixed ratio to input the preliminary boosted AC into the series resonant module, which reduces the volume of the DC high-voltage source, increases its capacity, and facilitates on-site withstand voltage tests.

The utility model adopts a double-closed-loop control strategy of the capacitor voltage average value outer loop inductance current instantaneous value inner loop in the DC high voltage generator based on series resonance, so as to realize stable and precise control of the system. The control block diagram is shown in Figure 3, in which G _v is a PI regulator, G _i is a P regulator, and the inductor current and capacitor voltage in the LC filter circuit in the series resonant step-up module 5 are sent to the DSP processing unit 8. 3 After the processing of the control algorithm, it is compared with the carrier wave to generate a SPWM wave, which is finally sent to the drive circuit 10 to generate a drive signal to drive the IGBT full-bridge inverter module 4 . The speed of the inner loop is fast, and a proportional regulator is used. When the sine wave is given, the instantaneous value inner loop feedback can make the output voltage waveform closer to the sine wave and reduce the distortion of the output voltage. The average value outer loop adopts PI regulator, the speed is relatively slow, but it can ensure the accuracy of the output voltage, which is beneficial to find the resonance point during frequency sweep.

The utility model adopts the control method of frequency modulation first and then voltage regulation in the direct current high-voltage generator based on series resonance. The frequency is roughly swept (1Hz/1s) before the resonance point, and the frequency is finely swept (0.1Hz/1s) near the resonance point. 1s), making the obtained results more accurate.

The utility model adopts TMS320F28335 as the DSP processing unit 8 in the DC high voltage generator based on series resonance. This digital processing chip adds a floating-point operation core to the existing DSP platform. While maintaining the advantages of the original DSP chip, it can perform Complex floating-point operations can save code execution time and storage space, and have the characteristics of high precision, low cost, low power consumption, high performance, high integration of peripherals, and large storage capacity of data and programs.

The DSP processing unit 8 is provided with over-current and over-voltage protection. Once a fault signal is detected during operation, the DSP processing unit 8 controls the protection circuit 9 to cut off the power supply immediately.

The STM display control circuit 11 in the DC high voltage generator based on series resonance of the utility model adopts STM32F103C8T6, which maintains real-time communication with the DSP processing unit 8 through RS232, and realizes serial port printing through RS232 communication with the serial port printing module 13 (printer), and displays with LCD Module 12 (LCD screen) exchanges data through TTL level. After the system is powered on and initialized, it enters the main interface, and the user controls the relevant parameter settings and the selection of the working mode through the button control module 14 (as shown in Figure 4). After the settings are saved, the STM display control circuit 11 issues commands via RS232 to the DSP processing unit 8. During the test, the DSP processing unit 8 sends the sampling data, including the current frequency, power, voltage and current, etc. to the STM display control circuit 11, and the STM display control circuit 11 displays the data on the LCD screen in real time after receiving the data.

The utility model is based on the series resonance DC high-voltage generator output voltage 0-300kV continuously adjustable, smaller in size, lighter in weight, larger in capacity, easy to operate, complete in function, convenient for operators to carry out on-site voltage withstand test, and convenient for field use , has broad marketing prospects.

Claims (4)

1. a kind of high voltage direct current generator based on series resonance, it is characterised in that including the EMI power filter moulds being sequentially connected Block (1), PFC module (2), bridge rectifier filtration module (3), full-bridge inverting module (4), series resonance boost module (5), rectification Times die block (6), electric current, series resonance boost module on voltage and inductance in full-bridge inverting module (4) output lateral capacitance (5) electric current on outlet side inductance, rectification and voltage multiplier module (6) outlet side access voltage x current modulate circuit (7), voltage x current Modulate circuit (7) is connected with DSP processing units (8), and DSP processing units (8) are connected to protection circuit (9), drive circuit respectively (10), STM display control circuits (11), STM display control circuits (11) are connected to LCD display module (12) respectively, by key control Module (14), drive circuit (10) is connected with the outlet side of bridge rectifier filtration module (3).

2. a kind of high voltage direct current generator based on series resonance according to claim 1, it is characterised in that the STM Serially printing module (13) is also associated with display control circuit (11).

3. a kind of high voltage direct current generator based on series resonance according to claim 1, it is characterised in that the full-bridge Fin is housed on the IGBT of inversion module (4), temperature sensor, temperature sensor and the DSP treatment are housed on fin Unit (8) is connected.

4. a kind of high voltage direct current generator based on series resonance according to claim 1, it is characterised in that the full-bridge Inversion module (4) uses the SPWM modulation systems of unipolarity frequency multiplication.