A Current Transformer Signal Conditioning Circuit with Short Circuit and Open Circuit Detection Function

Abstract

The invention discloses a current transformer signal conditioning circuit with a short circuit and open circuit detection function. The current transformer signal conditioning circuit comprises an upper computer MCU and a signal conditioning circuit, wherein the signal conditioning circuit comprises an operational amplifier OP1, an operational amplifier OP2, a resistor R1, a resistor R2 and a capacitor C1, a negative electrode of an input end of the operational amplifier OP1 is connected with the resistor R1, the resistor R2, a resistor R3 and a transformer L, and a positive electrode of the input end of the operational amplifier OP1 is connected with a resistor R4 and the capacitor C1, and the positive electrode of the input end of the operational amplifier OP2 is connected with the otherend of the transformer L. The current transformer signal conditioning circuit disclosed by the invention has the beneficial effects that, 1. the open circuit fault is measured and judged at the sametime by using double ADs, thereby effectively reducing the false alarm possibility of the open circuit. 2. The short circuit fault is judged by using a method of injecting orthogonal resonant signal,so that the capacitance and the inductance in the circuit resonate, which greatly reduces the false alarm possibility of the short circuit caused by external electromagnetic interference.

Description

technical field [0001] The invention relates to a signal conditioning circuit, in particular to a current transformer signal conditioning circuit with short circuit and open circuit detection functions. Background technique [0002] In the current detection of high-voltage and low-voltage power systems, current transformers are widely used in current conversion and sensing devices, and the open circuit and short-circuit faults of current transformers directly affect the safe and reliable operation of equipment. [0003] At present, the open circuit and short circuit faults of current transformers are mostly judged by the sudden change of software measurement value. This method is susceptible to external electromagnetic interference, and then false alarms of open circuit and short circuit occur. The invention proposes a new type of current transformer conditioning circuit, using double AD simultaneous measurement to judge the open circuit fault, using the method of pouring or...

AI Technical Summary

Problems solved by technology

[0003] At present, the open circuit and short circuit faults of current transformers are mostly judged by the sudden change of the software measurement value. This method is easily affected by external electromagnetic interference, and then there are false reports of open circuit and short circuit.

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