Circuit breaker and impedance detection method of contact mechanism thereof

Abstract

According to the circuit breaker and the contact mechanism impedance calculation method, a measuring circuit and electrifying loops are included, each electrifying loop comprises a set of contact mechanisms used for controlling the electrifying loops to be switched on and switched off, and the measuring circuit comprises a controller, a current sensor and a voltage measuring circuit. The current sensor and the voltage measuring circuit are respectively connected with the controller and are used for transmitting a current signal and a voltage signal to the controller, and the controller calculates the impedance of the contact mechanism according to the current and the voltage; the current sensor is connected with the contact mechanism in series, the voltage measuring circuit is connected to the two ends of the contact mechanism in parallel, the voltage measuring circuit comprises a voltage sensor and an on-off device with a stroke function, and the on-off device is driven by the controller to generate displacement for closing or opening the voltage measuring circuit. According to the invention, the voltage measuring circuit is switched on or switched off by controlling the on-off device, so that the measuring circuit cannot form a current loop when the contact mechanism is switched off, and the electric leakage hidden danger of the circuit breaker is avoided.

Description

technical field [0001] The invention relates to low-voltage electrical appliances, in particular to an impedance detection method for a circuit breaker and a contact mechanism thereof. Background technique [0002] Circuit breaker, also known as automatic air switch or automatic air circuit breaker, is an electrical appliance that has both manual switching functions and automatic voltage loss, undervoltage, overload and short circuit protection. It can be used to distribute electric energy, start asynchronous motors infrequently, protect power supply lines and motors, etc., and automatically cut off the circuit when they have serious overload or short-circuit and under-voltage faults. Its function is equivalent to a fuse switch and Overheating relay and other combinations. [0003] The contact mechanism is an important part of the circuit breaker. It can control the energization or power-off of the line by closing or opening, but each closing and opening of the contact mech...

AI Technical Summary

Problems solved by technology

[0003] The contact mechanism is an important part of the circuit breaker. It controls the power on or off of the line by closing or opening the switch. However, every closing and opening of the contact mechanism will cause the attenuation of the contact mechanism and cause an open circuit. The increase of circuit breaker impedance leads to increased power consumption and reduced power transmission efficiency. With the continuous increase of power consumption, it will eventually lead to the failure of the circuit breaker

At present, existing circuit breakers cannot measure the on-resistance of the contact mechanism of the circuit breaker in real time. The main reason is that the measurement circuit cannot be isolated from the line of the circuit breaker. Overload is likely to cause the risk of leakage and potential safety hazards. Therefore, since the conduction resistance of the contact mechanism cannot be measured in real time, it is impossible to accurately detect the working status of the circuit breaker and predict the life of the circuit breaker.

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