STATCOM (Static Compensator) device based on switched system theory and robust control method for same

Abstract

The invention provides a STATCOM (Static Compensator) device based on a switched system theory. The STATCOM device comprises a reactor L, a voltage type inverter, a driving circuit, an outer ring control module and an inner ring control module. A control method for the STATCOM device comprises the following steps of modeling, signal acquisition, synchronous compensation, stability verification and feedback control. The control method has the following advantages that: (1) when a system is in failure, the stability of the system can be ensured, and interferences on performances of the system can be eliminated; (2) a confirmed voltage output function can reduce parameters which are taken into consideration in operation, and only parameters of resistance and inductance are required; (3) optimized indexes can be confirmed through a determined robust control model according to the definition of H (infinite) control of the control method; (4) the utilization of constraint conditions of an LMI (Linear Matrix Inequality) solving controller is the most convenient; and (5) the effectiveness and correctness of STATCOM compensation can be achieved by reasonably switching a turnoff device in a main circuit of the inverter based on switching rules, the utilization rate of the device is increased, and the service life of the device is prolonged.

Description

(1) Technical field: [0001] The invention belongs to the field of power electronics technology and robust control technology, especially a STATCOM (Static Synchronous Compensator) device based on switching system theory and its H ∞ Robust control method. (two) background technology: [0002] At present, the research on static var compensator STATCOM mainly focuses on the main connection mode and topology, system modeling, system control method and its effect on power system stability. The world's first STATCOM industrial device developed by Westinghouse Corporation of the United States uses a gate-level turn-off thyristor GTO (Gate Turn-Off Thyristor). The waveforms output by multiple inverters are phase-shifted and superimposed to obtain a three-phase symmetrical output voltage similar to a sinusoidal waveform. The STATCOM industrial devices put into operation at home and abroad will adopt the same main circuit structure above, which is called a multiple structure. The mu...

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Problems solved by technology

Although this structure is very effective, it not only increases the cost, but also makes the system more complex because of the need for a specially designed zigzag transformer, and the complex electromagnetic coupling between the phases also makes it difficult to control the phase separation when it is asymmetrical.

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