Medium voltage cs-apf double hysteresis loop fault-tolerant control method based on voltage vector method

Abstract

The invention relates to a medium-voltage CS-APF (Cascaded Shunt Active Power Filter) dual-hysteresis fault-tolerant control method based on a voltage space vector method, and aims to solve the problem of high failure probability of a cascaded circuit existing in a CS-APF and effectively reduce the cost. In a non-failure state, the rapidness of current tracking is mainly considered when a current tracking error is large, and accuracy is mainly considered when the error is small; in a failure state, an optimal non-failure voltage vector is selected to equivalently replace a failure voltage vector as far as possible by making full use of the characteristics of a great number of redundant voltage vectors of a cascaded inverter and frequent coincidence of positions, so that the output current of the CS-APF can be used for accurately tracking a reference value in the failure state. Compared with the conventional frequently-used N+1 redundant fault-tolerant way, the method has the advantages that additional hardware redundant resources do not need to be added, cost is reduced, and the working reliability of a medium-voltage active power filter is improved remarkably; the method can be popularized into a CS-APF of any order.

Description

technical field [0001] The invention relates to the technical field of active power filters, in particular to a medium-voltage CS-APF double-hysteresis fault-tolerant current control method based on a voltage space vector method. Background technique [0002] At present, the filter devices of my country's medium-voltage power system are mainly passive filters, including passive power filters FC, thyristor switched capacitors TSC and thyristor controlled reactors TCR, etc. It has the disadvantages of fixed parameters, inflexible compensation, only specific harmonics can be filtered out, and resonance is easy to occur. Therefore, the adjustment effect of harmonics is not good, and the quality of power supply needs to be further improved. [0003] Active power filter (APF for short) has a high degree of controllability and rapid response, and is an ideal filtering device for controlling harmonic pollution and improving power quality. At this stage, APF technology has been suc...

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Problems solved by technology

[0016] In order to solve the problem of high failure probability of medium-voltage CS-APF and reduce hardware cost as much as possible, the present invention provides a medium-voltage CS-APF double hysteresis loop fault-tolerant control method, making full use of the redundancy of cascaded inverters Voltage vector realizes fault-tolerant control, so that CS-APF can more accurately compensate harmonic current under fault conditions, thereby improving the power supply quality of my country's medium-voltage power system

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