A Modulation Method of Inverter Switching Frequency Considering Inductor Saturation Characteristics

Abstract

The invention discloses a variable switching frequency modulation method considering inductor saturation characteristics. The modulation method is based on a current ripple prediction model considering inductor saturation, and the current ripple distribution is controlled by updating the inverter switching frequency in real time. By adopting the variable switching frequency modulation method of the present invention, under the condition of saturation of the filter inductor, the current ripple in each switching cycle can still be effectively predicted, and the switching frequency of the inverter is jittered with the current ripple as the control object. Compared with the traditional PWM method of fixed switching frequency, the average switching frequency is reduced, which directly reduces the switching loss of the inverter system; 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. [0002] technical background [0003] 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 calcu...

AI Technical Summary

Problems solved by technology

[0004] 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

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