A phase-selection switching control method for a non-contact regulating voltage stabilizing device

Abstract

The invention provides a phase-selection switching control method of a non-contact regulating voltage stabilizing device, including the following: designing the structure of a non-contact compensation type AC voltage stabilizing device; according to the structure of the non-contact compensation type AC voltage stabilizing device, analyzing its Working principle, the relationship between the output voltage and the input voltage of the non-contact compensation type AC voltage stabilizing device is obtained; the circuit model of the three-phase voltage regulating transformer is simplified, and the main magnetic flux of the three-phase voltage regulating transformer is obtained by calculation; the analysis of the three-phase voltage transformer For the main magnetic flux of the voltage regulator, a phase selection switching strategy based on load characteristics is designed, and then the switching mode of the thyristor assembly is changed, and the excitation inrush current existing in the switching process of the non-contact compensation AC voltage stabilizing device is suppressed. The beneficial effects provided by the invention are: maximally restraining the excitation inrush current during the phase selection and switching process of the non-contact regulating and stabilizing device, and ensuring the stability and reliability during the switching process of the device.

Description

technical field [0001] The invention relates to the field of electric control, in particular to a phase-selection switching control method of a non-contact regulating and stabilizing device. Background technique [0002] In the low-voltage distribution network, the grid voltage is susceptible to large and frequent fluctuations due to load changes. In addition, after the introduction of new energy sources, the fluctuation of new energy output will lead to voltage fluctuations. Voltage fluctuations are inevitable, especially in radial networks. In order to stabilize the grid voltage, connect the grid, and adjust the load flow, it is necessary to carry out dynamic automatic voltage adjustment. Due to its simple structure and controllable cost, non-contact compensation AC voltage stabilizing devices (hereinafter referred to as three-phase dynamic compensating devices) are widely used in the field of voltage stabilization and regulation in low-voltage distribution networks. At ...

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Problems solved by technology

[0004] (1) Use circuit breaker switching resistance to limit the amplitude and transient process of inrush current, but this method increases investment cost and operation complexity; (2) A method that uses neutral point series resistance to limit transformer excitation inrush current method, but there are great difficulties in parameter setting and mechanical realization of the device; (3) A second-order under-damped circuit is used to suppress the inrush current, but only a theoretical analysis is carried out; (4) by giving The transformer is pre-magnetized so that the residual magnetism is close to the limit residual magnetism, and then the phase is selected to switch the transformer, but this method is not suitable for the topology of the non-contact compensation AC voltage stabilizing device; (5) According to the original To estimate the remanence of the transformer core by finding the core saturation time based on the voltage, current data and switching angle of the side

[0005] The common point of the above methods is that the process of obtaining model parameters is complicated, which is not very suitable for actual engineering

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