the
1
Introduction
Currently, the ozone generator, sewage treatment, flue gas desulphurization, high power laser, plasma discharge technology, voltage inverter power supply is being more and more applications. The traditional high-voltage power inverter generally by a commercial frequency or the IF transformer directly boost or LC series resonant inevitably have large volume and low efficiency. Many occasions that require high-voltage power supply, better high frequency high voltage power supply effect is much higher than the power frequency, and high frequency power, small size, light weight, and the future development directionpower inverter. This article describes a dielectric barrier discharge generator dedicated supporting high voltage sine wave inverter. The dielectric barrier discharge generator from an insulating material and etched from both ends of the insulating material of the discharge electrode is composed of two parts, as shown in Figure 1. Added to the medium in the gap of the discharge electrode layer can effectively suppress the increase of the discharge current, and help in the medium at both ends to form a stable plasma layer. Its equivalent circuit can be approximated as a capacitor and resistor in parallel composition, this capacitive load power must be taken into account when designing the filter characteristics. In order to study the characteristics of the discharge means at different voltages and frequencies, and the necessary supporting the power supply output voltage and frequency fluctuation range. The purpose of this device, the power supply requirements are: to be able to reach 20kV output voltage, output current up to 1A, the frequency range is 5 to 20kHz pure sinusoidal waveform. The following describes the design features of the power supply.
Currently, the ozone generator, sewage treatment, flue gas desulphurization, high power laser, plasma discharge technology, voltage inverter power supply is being more and more applications. The traditional high-voltage power inverter generally by a commercial frequency or the IF transformer directly boost or LC series resonant inevitably have large volume and low efficiency. Many occasions that require high-voltage power supply, better high frequency high voltage power supply effect is much higher than the power frequency, and high frequency power, small size, light weight, and the future development directionpower inverter. This article describes a dielectric barrier discharge generator dedicated supporting high voltage sine wave inverter. The dielectric barrier discharge generator from an insulating material and etched from both ends of the insulating material of the discharge electrode is composed of two parts, as shown in Figure 1. Added to the medium in the gap of the discharge electrode layer can effectively suppress the increase of the discharge current, and help in the medium at both ends to form a stable plasma layer. Its equivalent circuit can be approximated as a capacitor and resistor in parallel composition, this capacitive load power must be taken into account when designing the filter characteristics. In order to study the characteristics of the discharge means at different voltages and frequencies, and the necessary supporting the power supply output voltage and frequency fluctuation range. The purpose of this device, the power supply requirements are: to be able to reach 20kV output voltage, output current up to 1A, the frequency range is 5 to 20kHz pure sinusoidal waveform. The following describes the design features of the power supply.
(a) generator diagram (b) equivalent
circuit
Figure 1 dielectric barrier discharge generator and its equivalent circuit diagram of
high voltage sine wave The high-voltage sine wave inverter schematic variable frequency inverter design
this design is shown in Figure 2. Input power phase 380V, after the three-phase bridge rectifier can be obtained about 540V DC voltage (the change of fluctuations) with the grid voltage. The DC voltage through the DC / DC converter to obtain an output amplitude of a variable DC voltage, and the change is designed to be in the range of 0 ~~ 500V. The transform ordinary Buck buck conversion circuit can be realized. Variable DC voltage square wave output full-bridge DC / AC inverter circuit. The square wave through LC filter can be obtained sine wave output. Filter inductor itself by the external inductor and transformer leakage inductance composition, filter capacitor constituted by the transformer stray capacitance and load capacitance. The low-voltage sine wave final high-voltage high-frequency transformer boost to get the required high voltage sine wave. Usually the inverter only by a transform of the DC / AC can simultaneously achieve the functions of the inverter and the transformer, but in this case the requirements on the output waveform, and the output frequency is high, good high frequency modulation, therefore, two-stage conversion, frequency conversion and transformer function.
Figure 1 dielectric barrier discharge generator and its equivalent circuit diagram of
high voltage sine wave The high-voltage sine wave inverter schematic variable frequency inverter design
this design is shown in Figure 2. Input power phase 380V, after the three-phase bridge rectifier can be obtained about 540V DC voltage (the change of fluctuations) with the grid voltage. The DC voltage through the DC / DC converter to obtain an output amplitude of a variable DC voltage, and the change is designed to be in the range of 0 ~~ 500V. The transform ordinary Buck buck conversion circuit can be realized. Variable DC voltage square wave output full-bridge DC / AC inverter circuit. The square wave through LC filter can be obtained sine wave output. Filter inductor itself by the external inductor and transformer leakage inductance composition, filter capacitor constituted by the transformer stray capacitance and load capacitance. The low-voltage sine wave final high-voltage high-frequency transformer boost to get the required high voltage sine wave. Usually the inverter only by a transform of the DC / AC can simultaneously achieve the functions of the inverter and the transformer, but in this case the requirements on the output waveform, and the output frequency is high, good high frequency modulation, therefore, two-stage conversion, frequency conversion and transformer function.
Figure 2 high-voltage variable
frequency inverter power supply schematic
DC / DC part SG3525 control to change the DC output by changing the duty cycle of the output voltage. The DC / AC part of the function is only the DC into AC, therefore, the part of the control chip is also used SG3525.pdf, and its duty cycle remains substantially unchanged during operation, only the frequency change within a set range. 80C196KC microprocessor in the entire circuit is mainly played the role of a man-machine interface. It is responsible for receiving control instructions and process parameters and status display. Keyboard and display interface circuit through the 8255 chip to achieve communication with the CPU. The parameter adjustments interfaces is mainly responsible for the 80C196KC output instructions sent to the SG3525 power control chip, to achieve the adjustment of the output voltage and frequency of power supply. All power switches IGBT, power tube drive dedicated the IGBT driver control chip M57959L within the chip with optical isolation and over-current protection circuit, it is more convenient to use. http://www.gridtieinverter.de/
DC / DC part SG3525 control to change the DC output by changing the duty cycle of the output voltage. The DC / AC part of the function is only the DC into AC, therefore, the part of the control chip is also used SG3525.pdf, and its duty cycle remains substantially unchanged during operation, only the frequency change within a set range. 80C196KC microprocessor in the entire circuit is mainly played the role of a man-machine interface. It is responsible for receiving control instructions and process parameters and status display. Keyboard and display interface circuit through the 8255 chip to achieve communication with the CPU. The parameter adjustments interfaces is mainly responsible for the 80C196KC output instructions sent to the SG3525 power control chip, to achieve the adjustment of the output voltage and frequency of power supply. All power switches IGBT, power tube drive dedicated the IGBT driver control chip M57959L within the chip with optical isolation and over-current protection circuit, it is more convenient to use. http://www.gridtieinverter.de/
3 circuit design several key issues
3.1 high-voltage high-frequency transformer design
ordinary switching power supply input and output are low pressure, most of the input and output in less than a few hundred volts, so , not very different sides of the original design of the ordinary high-frequency transformerGrid tie inverter, the better deal. High-voltage high-frequency transformer design more difficult, it has two features:
1) insulation problems hard to deal with, the smaller the size, the higher the insulating material requirements;
2) secondary turns far higher than the original edge turns, resulting in high-voltage high-frequency transformer secondary side distribution parameters of the circuit, especially in the high-frequency case, the secondary of the transformer leakage inductance and stray capacitance will greatly affect the energy transmission process.
Therefore, the analysis of this transformer is also different from the ordinary high-frequency transformer. The equivalent circuit diagram of the high-voltage transformer shown in Figure 3. Wherein the transformation ratio is 1: N of the transformer is not consider the distribution parameter of the ideal transformer. Lp, Ls is the the original secondary side leakage inductance, Rp, Rs is the equivalent resistance of the original secondary windings, Cp, Cs is the stray capacitance of the sides of the original.
This article is from the: http://www.12vgridtiepowerinverters.com/
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