Magnetic isolation-based AC (Alternating Current) detecting circuit capable of reflecting DC (Direct Current) bias state

Abstract

The invention discloses a magnetic isolation-based AC (Alternating Current) detecting circuit capable of reflecting a DC (Direct Current) bias state, and belongs to the technical field of AC detecting circuits. The magnetic isolation-based AC detecting circuit capable of reflecting the DC bias state comprises a double-current transformer sensing circuit, an uncontrolled rectifying circuit and a resistance sampling circuit, wherein the double-current transformer sensing circuit is formed by a first current transformer and a second current transformer; the uncontrolled rectifying circuit is formed by a first diode, a second diode, a third diode and a fourth diode; the resistance sampling circuit is formed by a first resistor, a second resistor and a third resistor. According to the magnetic isolation-based AC detecting circuit capable of reflecting the DC bias state disclosed by the invention, current transformers are utilized for detection, an auxiliary power supply is not required for supplying power, the cost is low, the reliability is high, and the detection speed is fast; the whole circuit is simple in structure and easy to realize; DC bias of the AC can be effectively reflected, and the detecting accuracy is higher.

Description

technical field [0001] The invention relates to an AC current detection circuit capable of reflecting a DC bias state based on magnetic isolation, and belongs to the technical field of AC current detection circuits. Background technique [0002] The application of power electronics technology can greatly increase the power density of electric energy conversion devices, reduce volume and weight. With the development of multi-electric and all-electric aircraft, the power consumption of aircraft continues to increase, and there are more and more power electronic devices on board. In the control of the airborne power electronic conversion device, it is necessary to accurately detect the current waveform to complete the excellent control and protection circuit functions. [0003] In power electronic converters, current detection methods mainly include Hall element detection, resistance sampling and current transformer detection. The Hall element can accurately sample the curren...

AI Technical Summary

Problems solved by technology

The Hall element can accurately sample the current, but it needs an auxiliary power supply, which increases the cost, weight and volume of the entire system. At the same time, the failure rate of the Hall element is relatively high, which affects the reliability of the system.

Resistance sampling is suitable for occasions with small and medium power, and the characteristics of sampling resistance are greatly affected by environmental factors, and the sampling accuracy cannot be guaranteed

The current transformer is also often used to detect the current, but due to the defect of the current transformer itself, it can only sample the AC component, so it cannot accurately sample the AC current

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