A device for online testing of circuit breaker protection characteristics

Abstract

The invention provides a device for online testing of circuit breaker protection characteristics, including a front-stage subsystem composed of an AC power supply, a rectifier bridge, a high-frequency filter capacitor and a boost chopper DC converter, and a full-bridge inverter circuit, The post-stage subsystem composed of filter circuit, current booster and load; also includes PI type Sugeno fuzzy control loop and load impedance adaptive compensation circuit; the former is based on PI type Sugeno fuzzy controller, and introduces tracking error signal for compensation, Combined with PI control to reduce the concave and convex points existing in the fuzzy control rules, it provides a series of driving voltage pulse waveforms with stable output with improved power factor. Difference compensation to improve output current accuracy. By implementing the present invention, compensation is performed at the input end of the preceding stage to improve the tracking ability of the DC voltage of the preceding stage, reducing waveform distortion, and feedforward compensation is also performed at the current output end of the latter stage to improve the accuracy of the test current.

Description

technical field [0001] The invention relates to the technical field of circuit breaker testing, in particular to a device for on-line testing of circuit breaker protection characteristics. Background technique [0002] Circuit breaker is an important electrical equipment in the distribution network. It mainly provides protection functions such as overload and short circuit of the electrical circuit. Its protection characteristics play an important role in ensuring the safety of the distribution network. National standards stipulate that the protection characteristics of circuit breakers need to be verified before leaving the factory to ensure product quality and reliability. It is an important method to test the performance of the circuit breaker by using the current converter to check the protection characteristics of the circuit breaker on-line. The early circuit breaker protection characteristic testing device mainly used the combination of voltage regulator and current ...

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Problems solved by technology

For example, Ling Rongrong, Pan Yibin, Huang Shuhang and others proposed the design and realization of the circuit breaker protection characteristic experimental device (China Electric Power Education 2012, 226(3): 117-118), and the circuit breaker protection is carried out by designing the circuit breaker protection characteristic experimental device Characteristic test, but limited by the power regulator, the device is large in size, and the accuracy and efficiency of the circuit breaker test are limited

With the development of power electronics technology, the current converter based on the combination of power electronics conversion technology and automatic control theory has gradually become a new direction for testing the protection characteristics of circuit breakers. Harmonic pollution caused by current distortion; at the same time, the test process does not consider the impact of load changes on current accuracy, and its test accuracy needs to be improved

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