How to improve the power factor of the basic rectifier circuit?

乱世煮酒论天下

How to improve the power factor of the basic rectifier circuit? [Copy link]

Rectification is divided into basic diode rectification, thyristor half-controlled rectification, and PWM fully controlled rectification. Fully controlled PWM rectification can achieve controllable power factor.

So for the other two rectification methods, diode rectification and half-controlled rectification, is there any way to improve their power factor? I have seen before that you can add an input reactor. The input reactor is an inductive load and compensates for the capacitive load. Then the basic rectification is a capacitive load, and the current leads the voltage.

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The reactive power of the rectifier circuit is caused by the distortion of the current and the harmonic current. To improve the power factor, a power factor correction circuit PFC must be added.

qwqwqw2088

Using LC filters can suppress high-order harmonics in the current and improve the power factor.

乱世煮酒论天下

qwqwqw2088 posted on 2024-11-5 08:54 Using LC filters can suppress high-order harmonics in the current and improve the power factor

Can we say that it is the high-order harmonics of the current in the basic rectifier circuit that affect the power factor, and the capacitive load is correct?

qwqwqw2088

Luan Shi Zhu Jiu Lun Tian Xia published on 2024-11-5 09:22 Can we say that it is the high-order harmonics of the current in the basic rectifier circuit that affect the power factor, and the capacitive load is correct

That's what I mean

High-order harmonics will increase the effective value of current, keep the effective value of voltage unchanged, and reduce the power factor.

qwqwqw2088

Capacitive loads can provide reactive power to offset the problem of excess reactive power caused by harmonics.
In some cases, adding capacitance can improve the power factor.