A quasi-single-stage inverter without electrolytic capacitor and its control method

Abstract

The invention discloses an electrolytic capacitor-free quasi single stage inverter and a control method therefor. A main circuit topology of the quasi single stage inverter comprises a direct current power source, an input filtering capacitor, a main switch tube, an isolation voltage transformer, a rectification circuit, a filter circuit, a polarity reversal inversion bridge, a load and an active auxiliary circuit, wherein the control method comprises the following steps: a low frequency component is extracted from auxiliary inductive current sampling value via a low pass filter; a subtracter and a P controller are used for obtaining auxiliary inductive current modulated waves, the auxiliary inductive current modulated waves go through a comparator and a drive circuit, an auxiliary inductive current is controlled and reference value thereof is tracked; three modulated waves are obtained after auxiliary capacitor voltage sampling value and load voltage sampling value are processed via a modulated wave calculating module; the three modulated waves go through the comparator, a logic circuit, a frequency division circuit and the drive circuit; the inverter can be controlled to work according to requirements. Via the quasi single stage inverter and the control method therefor, power ripple waves brought by an alternating current load are introduced into an active auxiliary circuit, and therefore no large electrolytic capacitor is needed in the circuit for filtering low frequency power ripple waves.

Description

technical field [0001] The invention relates to a quasi-single-stage inverter without an electrolytic capacitor and a control method thereof, and belongs to the technical field of new energy power conversion ripple suppression. Background technique [0002] In recent years, humans have paid more and more attention to the natural environment. Clean, efficient and sustainable new energy power technologies have attracted widespread attention. Some inverter topologies and control schemes for new energy power generation have emerged. For this kind of inverter, the double-frequency power pulsation contained in the AC output power will inevitably be fed back and transmitted to the DC input side, thereby affecting the service life of input sources such as batteries and fuel cells, and in severe cases will interfere with the stability of the DC power system , so it is urgent to solve the power ripple problem in the new energy power generation system and improve the utilization effici...

AI Technical Summary

Problems solved by technology

All in all, these commonly used methods of relying on passive components to filter out power ripples often have problems such as large size and high cost.

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