Power conversion circuit

Abstract

A power converting circuit for supplying power to an inductive load, includes an inductance, a switching circuit and an energy saving circuit. The inductance is charged when the switching circuit is conductive and discharges energy to the energy saving circuit and the inductive load when the switching circuit is nonconductive. The energy saving circuit discharges energy to the inductive load when the switching circuit is conductive.

Description

technical field [0001] The invention relates to a power conversion circuit, in particular to a power conversion circuit which can be used in a drive circuit of a brushless direct current motor and can reduce current phase shift and negative power and improve effective output power. Background technique [0002] A brushless DC motor has coils wound around the stator or rotor, which are inductive elements. The motor can be connected to an AC power source through a power conversion circuit that converts AC to DC. Please combine figure 1 , when the motor is powered on, the current enters the coil of the brushless DC motor stator, and the energy is stored in the magnetic field generated by the coil. Since the coil is an inductive load, the phase of the current lags the phase of the voltage. When the motor is powered on, the motor is stationary and the coil has no counter electromotive force. As the power supply voltage gradually increases, the current enters the coil to genera...

AI Technical Summary

Problems solved by technology

In this way, not only the effective output of the motor is reduced, but also the occurrence of negative power, so that part of the electric energy returns to the grid

Since the grid has resistance, the return current consumes energy and wastes energy

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