Circuit for reducing input harmonics of AC power supply

Abstract

The embodiment of the invention provides a circuit for reducing input harmonics of an AC power supply, which comprises a bus and a time sequence switch circuit, wherein two ends of the bus are respectively connected with the output end of the time sequence switch circuit; the bus is provided with a capacitor; the time sequence switch circuit comprises multiple insulated gate bipolar transistor (IGBT) modules; the multiple IGBT modules are in parallel connection; the multiple IGBT modules are connected with a controller; the time sequence switch circuit is also connected with the input end of the AC power supply; inductors and switches are connected between the input end of the AC power supply and the time sequence switch circuit; and the switches are in parallel connection with the inductors. Thus, the input current can track the waveform of input voltage in a dynamical and real-time mode, the waveform of the input current is close to a sine wave, the input current and the voltage have the same phase, the output power can be improved, and the AC input harmonics can also be reduced.

Description

technical field [0001] The invention relates to the technical field of AC power current correction, in particular to a circuit for reducing input harmonics of an AC power supply. Background technique [0002] With the vigorous promotion and use of the 400Hz intermediate frequency static variable power supply at the airport, the performance and indicators of the AC input side of the intermediate frequency power supply have also received more and more attention. Judging from the update of the intermediate frequency power supply standard by the Civil Aviation Administration, the static variable power supply should be able to work normally, and the AC input harmonics must be less than 10%. From the perspective of places such as airports that have high requirements for electromagnetic compatibility, it is necessary to reduce the input harmonics of the intermediate frequency power supply. , Improving the performance of the intermediate frequency current input side is necessary for...

AI Technical Summary

Problems solved by technology

[0003] In the existing technology, through the combination scheme of phase-shifting reactor and 12-pulse full-bridge rectifier, the AC input harmonics can be controlled at about 14%, but it cannot meet the requirement of 10%.

Another solution is to install an active filter on the AC input side of the intermediate frequency power supply to reduce the input harmonics. Although it can reduce the AC input harmonics of the intermediate frequency power supply, it is not flexible in capacity configuration and is very inconvenient.

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