380V system active power filtering device

Abstract

The invention discloses an active power filter of a 380V system, including an active filter branch 1, a current sensor CT1 connected to the three-phase current of the active filter branch 1, a current sensor CT2 connected to the three-phase current of the load, a voltage sensor PT connected to the three-phase voltage, as well as a digital signal processor 2 connected to the sasid four components; The apparatus also comprises a display and man-machine interaction control equipment communicating with the digital signal processor 2 through the system bus. The fast response characteristic and the high controllability of the invention have guaranteed the real-time of reactive power compensation; the invention raises the dynamic ability of eliminating harmonic, and reduces the adverse effect to the system electrical energy quality produced after the compensating input; and the invention also plays the role of stabilizing the voltage, compensation of the reactive power, and raising the efficiency factor.

Description

Technical field: [0001] The invention relates to an active power filter device for a 380V system, in particular to an active filter device developed by using power electronic technology and power electronic devices and applied to power quality control in a power system. Background technique: [0002] In practical applications, there are two main filtering methods to eliminate harmonics in the power supply system: passive LC filter and active power filter. [0003] At present, the most widely used in engineering is the passive LC filter, which has simple structure, low investment, high reliability and relatively low operating cost. Passive Power Filter (PPF for short) is usually composed of power capacitors, reactors and resistors according to functional requirements. The filtering principle is to provide a parallel low-impedance path, and the filtering characteristics are determined by the impedance ratio of the system and the filter, so PPF has the following disadvantages:...

AI Technical Summary

Problems solved by technology

The drift of LC parameters will lead to changes in filtering characteristics, making the filtering performance unstable;

[0005] (2) Parallel resonance may occur between the grid parameters and LC, which will amplify the harmonic component and degrade the power supply quality of the grid;

[0006] (3) It is difficult to coordinate filtering requirements with reactive power compensation and voltage regulation requirements;

[0007] (4) Passive parameters are prone to drift after aging, which ultimately fails to achieve the expected filtering effect

[0012] Previously, there were many studies on power active filters in China: for example, coupling transformer type series active power filters, but this active power filter can only compensate the positive half of the ripple voltage

There are also parallel-connected power active filters whose voltage level is difficult to reach the specified voltage, or the total harmonic distortion rate of the current has not been effectively reduced to the national specified value

Images