Inverter variable switching frequency modulation method considering inductor saturation characteristic

Abstract

The invention discloses a variable switching frequency modulation method considering an inductor saturation characteristic. The method is based on a current ripple prediction model considering inductor saturation, and controls the current ripple distribution by updating the switching frequency of an inverter in real time. The variable switching frequency modulation method provided by the inventionhas the advantages that, under the condition that a filter inductor is saturated, current ripples in all switching periods can still be effectively predicted and the current ripples serve as controlobjects to carry out jittering of the switching frequency of the inverter; compared with a traditional PWM method with the fixed switching frequency, the method has the advantages that the average switching frequency is reduced, and the switching loss of an inverter system is directly reduced; and secondly, the jitter of the switching frequency can effectively reduce the system conduction EMI.

Description

technical field [0001] The invention belongs to the field of power electronics, and more specifically relates to an inverter switching frequency modulation method considering inductance saturation characteristics. technical background [0002] In an inverter system using pulse width modulation technology, due to the excitation of PWM voltage, it is often necessary to design a filter to suppress high-frequency harmonics. However, the designed inductance value is often not an ideal fixed value, and will change in real time with the current according to the saturation characteristic of the inductance. When the actual inductance value varies widely, the prediction calculation of the current ripple will also be affected by it. The existing prediction calculation of current ripple often assumes that the inductance value of the filter inductor is fixed under any working condition, and does not consider the influence of the change of inductance value on the prediction calculation o...

AI Technical Summary

Problems solved by technology

[0003] Aiming at the improvement needs of the existing technology, the present invention provides a variable switching frequency modulation method considering the saturation characteristics of the inductor, which aims to solve the prediction and calculation of the existing current ripple, and does not consider the influence of the change of the inductance value on the prediction and calculation of the current ripple. Affects technical issues that cannot accurately predict and control current ripple

Images