Single-phase five-level boost power factor correction converter

Abstract

The invention relates to a single-phase and five-level boost type power factor correction converter, which comprises a diode single-phase full-bridge rectifier circuit, a boost inductor L, a power electronic switch network, a series capacitor network and a parallel resistor network. The boost inductor L is connected between the direct-current positive pole of the diode single-phase full-bridge rectifier circuit and the first end of the power electronic switch network. The second end of the power electronic switch network is connected with the direct-current negative pole of the diode single-phase full-bridge rectifier circuit. In this way, on the premise that a switch frequency and a maximum allowable inductor current ripple are kept consistent, the volume of the boost inductor is reducedby about 75%, and the total volume of the converter is greatly reduced. Or, on the premise that the output power, the switch frequency and the inductor volume are kept consistent, the amplitude of theinductor high-frequency ripple current is reduced by about 75%. The heating of the inductor is greatly reduced, and the efficiency of the converter is improved. The voltage stress of a switch tube can be reduced by about 50%, and the cost is reduced.

Description

technical field [0001] The invention belongs to the technical field of high power factor and high power density AC / DC converters for switching power supplies with high output voltage and high output power, and specifically relates to a single-phase five-level Boost type power factor correction converter. Background technique [0002] The input stage of a switching power supply usually adopts an uncontrollable capacitive rectification circuit composed of diodes. The advantages of this circuit are simple structure, low cost, and high reliability, but the fatal disadvantage is that its input current is not a sine wave, but is located near the peak voltage pulse wave. This current waveform contains a large number of low-order harmonic components, so the power factor of the circuit is very low, causing serious pollution to the power grid. [0003] The solution to this problem is to control the input current waveform of the rectifier circuit to make it as close to a sine wave as ...

AI Technical Summary

Problems solved by technology

However, there are two problems in this circuit: 1) In a switching cycle, the voltage change at both ends of the inductor is the output voltage, and the amplitude is relatively large, resulting in a large high-frequency switching ripple of the inductor current; 2) When the switch tube is turned off, its The voltage at both ends is the output voltage, and the voltage stress of the switch tube is high

When the output voltage of the switching power supply is high, the excessive high-frequency current will generate serious electromagnetic interference (EMI) on the one hand, and cause serious heating of the inductor on the other hand, so larger inductors, EMI filters and radiators must be used , which greatly increases the volume of the converter, increases the loss, and reduces the circuit efficiency; at the same time, when the output voltage of the switching power supply is high, a switch tube with higher voltage stress must be used, which increases the circuit cost

Therefore, this circuit is not suitable for high output voltage, high output power switching power supply occasions

Images