Active power filter based on digital resettable integral control

Abstract

The invention relates to an active power filter based on digital resettable integral control. The active power filter comprises a main power circuit and a control circuit, wherein the control circuitreceives a voltage signal Vc from a direct-current link capacitor C of the main power circuit and a grid-side current signal iac, whether to generate a gate driving signal used for controlling actionsof power switches S1, S2, S3 and S4 of the main power circuit is determined according to the voltage signal Vc and the grid-side current signal iac, and reset operation is performed on a resettable digital integrator. After the power switches S1, S2, S3 and S4 of the main power circuit perform corresponding actions according to the gate driving signal, the active filter can inject current with the same amplitude and opposite phase with the harmonic waves on the line into a grid-side line. Compared with an existing filter, the active filter provided by the embodiment of the invention is simplein circuit, avoids using a plurality of sensors, and can reduce the overall cost of the power filter.

Description

technical field [0001] The invention relates to the technical field of power electronics, in particular to an active power filter based on digital resettable integral control. Background technique [0002] Low-voltage distribution network loss reduction and efficiency increase are important tasks in power grid management. Low-voltage distribution network power loss accounts for a high proportion, complex causes, and difficult governance. With the increasing use of modern electronic equipment and devices, the grid is facing more and more nonlinear loads. In addition to consuming active power, nonlinear loads will also absorb reactive power and inject abundant harmonic currents into the grid. . These problems will lower the power factor of the grid, generate electromagnetic interference to adjacent loads and overheat distribution transformers, increasing the power loss of the low-voltage distribution network. [0003] The shunt active power filter makes the grid-side current...

AI Technical Summary

Problems solved by technology

In the common design method of active power filter, it is often necessary to sample the grid side voltage, grid side current, self current and DC link voltage or current to generate the reference reference required by the control circuit, so multiple sensors are required. The overall cost of the device is higher and the circuit is complicated

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