PFC inductor saturation suppression circuit and method and power equipment

Abstract

The invention relates to a PFC inductor saturation suppression circuit and method and power equipment. The circuit comprises a PFC main power circuit, a PFC inductor voltage sampling circuit, a PFC inductor current sampling circuit and a main control module. A PFC inductor value is calculated in real time by detecting voltages at two ends of a PFC inductor and the magnitude of a current which flows through the PFC inductor in real time; the saturation degree of the inductor is judged through the size of the PFC inductor value; and the magnitude of the current which flows through the PFC inductor is controlled according to the inductor saturation degree, so that the target of suppressing PFC inductor saturation is achieved. Only voltage detection circuits are added to two ends of the PFC inductor in the hardware realization aspect; the other operations are achieved through software calculation; and the extra hardware cost does not need to increase. Therefore, compared with an existing PFC inductor saturation suppression technology, the PFC inductor saturation suppression scheme provided by the invention is easy to achieve; and the cost is greatly reduced.

Description

technical field [0001] The invention relates to the technical field of PFC power factor correction, in particular to a PFC inductance saturation suppression circuit, method and power supply equipment. Background technique [0002] When the AC power supply is full-wave rectified and filtered by a large capacitor, when the flat DC voltage is directly applied to various converters and their loads, although the waveform of the input voltage is a sine wave, the waveform of the input current is a narrow pulse. , so that the line current contains a large number of harmonic components, and the power factor of the converter is greatly reduced. Extensive use of such power supply equipment will have many adverse consequences. A large number of harmonic currents will cause serious electromagnetic interference and harmonic pollution to the power grid, affect the normal operation of other equipment, cause line failures, and even damage power transmission and distribution equipment. ; Low...

AI Technical Summary

Problems solved by technology

However, in abnormal environments, such as fast switching on and off, frequent power outages, etc., if the PFC inductor is not well matched with the surrounding circuit, it will cause saturation of the PFC inductor, resulting in damage to the power devices in the surrounding circuit.

In order to suppress the saturation of the PFC inductor and prevent damage to the power devices in the PFC circuit, the prior art mainly adopts the following two methods: 1) Select a magnetic core with a larger specification than the theoretically calculated magnetic core, and add a surplus to the design of the inductor itself; 2) Choose power devices with larger specifications, but the above two methods will greatly increase the cost

Images