APF/SVG relay state detection system

Abstract

The invention provides an APF / SVG relay state detection system, which can prevent influence on a system and a power grid when a relay fails, and can realize timely protection, reduce a failure rate and improve equipment safety. The system comprises a charging module connected to a power grid, an IGBT module, a relay and a circuit breaking module connected with the power grid. The system also comprises a LCL filtering module, a charging module, a voltage sampling module, a signal comparison module and a control module; The LCL filtering module is connected between the circuit breaking module and the charging module and is used for filtering harmonic waves; the charging module is sequentially connected with the IGBT module and the bus voltage protection module and is used for charging the bus voltage protection module; the voltage sampling module is connected with the charging module and is used for sampling voltages at two ends of the charging module; the signal comparison module is connected with the voltage sampling module and is used for receiving the voltage signal acquired by the voltage sampling module and then processing the signal; and the control module is connected with the circuit breaking module after receiving the signal output by the signal comparison module and passing through the RELAY module, and is used for detecting the state of the relay and controlling whether the RELAY module acts or not according to the state of the relay.

Description

technical field [0001] The invention relates to the technical field of power quality control, in particular to a detection system for the state of an APF / SVG relay. Background technique [0002] APF (ActivePowerFilter, active power filter) and SVG (StaticVarGenerator, static var generator) are two commonly used power quality control devices; APF / SVG belongs to the active inverter topology, so the APF / SVG logic control circuit and the main The power inverter circuit is integrated into the power grid at the same time, so when the (magnetic latching) relay in the main power inverter circuit fails, the APF / SVG logic control components cannot be protected in time; but because the (magnetic latching) relay is Mechanical structure, after the (magnetic latching) relay in the main power inverter circuit undergoes operations such as equipment transportation, equipment installation, and multiple operations, the contacts of the (magnetic latching) relay will appear carbonized, causing t...

AI Technical Summary

Problems solved by technology

[0002] APF (ActivePowerFilter, active power filter) and SVG (StaticVarGenerator, static var generator) are two commonly used power quality control devices; APF / SVG belongs to the active inverter topology, so the APF / SVG logic control circuit and the main The power inverter circuit is integrated into the power grid at the same time, so when the (magnetic latching) relay in the main power inverter circuit fails, the APF / SVG logic control components cannot be protected in time; but because the (magnetic latching) relay is Mechanical structure, after the (magnetic latching) relay in the main power inverter circuit undergoes operations such as equipment transportation, equipment installation, and multiple operations, the contacts of the (magnetic latching) relay will appear carbonized, causing the contacts to not pull together , if the contact of the (magnetic latching) relay is accidentally touched, after the power is turned on at this time, the back-end equipment of the machine will withstand a current far exceeding the normal start-up, causing equipment damage, and if the (magnetic latching) relay does not operate according to the logic control, It will affect the function of the device, that is, there will be a risk of failure, which will lead to: (1) Standby risk: when the APF / SVG "cold machine" is connected to the grid, the BUS voltage of the device is charged through the charging resistor and IGBT module (with rectification), If the (magnetic latching) relay is in the closed state at this time, the "charging current" of the grid to the equipment is enough to damage the IGBT module and cause an impact on the grid; (2) Operation risk: when the equipment is running normally, the (magnetic latching) relay enters the off state In the off state, the device does not alarm, which seriously affects the compensation performance of the device

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