Relay state detection system and method applied to APF/SVG

Abstract

The invention provides a relay state detection system and method applied to the APF / SVG, additional cost does not need to be increased, relay state detection can be conveniently carried out, the detection result is accurate, misjudgment cannot be caused, and reliability is high; the system comprises a to-be-detected relay and a circuit breaker connected to a three-phase power grid, wherein the circuit breaker is electrically connected with an LCL filtering module, the to-be-detected relay, a current detection module, an inverter and a DC support capacitor in sequence; the LCL filtering module is used for filtering a three-phase alternating current; the current detection module is used for detecting the current provided for the inverter; and the inverter comprises IGBT units which are respectively connected to three phases, and the three phases of IGBT units are connected in parallel.

Description

technical field [0001] The invention relates to the technology of an active filter APF and a reactive power compensator SVG in the field of power quality management, in particular to a relay state detection system and method applied to the APF / SVG. Background technique [0002] APF (Active Power Filter, active power filter) and SVG (Static VarGenerator, static var generator) are two commonly used power quality control devices, both of which use IGBT (Insulated Gate Bipolar Transistor, insulated gate bipolar transistor) as power devices . [0003] APF / SVG products all have relay devices, but the existing APF / SVG on the market basically does not detect the status of relays, which is easy to cause failures during operation, and if a failure occurs, the components will be damaged at least, and the serious ones will be damaged. If it causes a fire, the reason for not doing detection is mainly that the technology is not in place or does not want to increase a large amount of dete...

AI Technical Summary

Problems solved by technology

[0003] APF / SVG products all have relay devices, but the existing APF / SVG on the market basically does not detect the status of relays, which is easy to cause failures during operation, and if a failure occurs, the components will be damaged at least, and the serious ones will be damaged. If it causes a fire, the reason for not doing detection is mainly that the technology is not in place or does not want to increase a large amount of detection cost; although some manufacturers have a detection scheme with relays in their products, it is to increase voltage or current sampling on both sides of the relay, not only Judgment basis is easily disturbed, not clear enough, easy to misjudge, and additionally increases the cost of voltage or current sampling and driving circuit or DSP control chip, which reduces product competitiveness in the market

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