AC charging pile output short circuit detection circuit and method

Abstract

The invention relates to an AC charging pile output short circuit detection circuit and method. The circuit comprises a first detection circuit and a second detection circuit. The first detection circuit comprises a first relay which comprises a first coil and a first contact which acts after the first coil is powered on, and the first contact is connected with a third contact in parallel. The second detection circuit comprises a second relay, the second relay comprises a second coil and a second contact acting after the second coil is powered on, and the second contact is connected with a fourth contact in parallel. The first detection circuit and the second detection circuit are both connected with an MCU and are used for controlling whether the first coil and the second coil are powered on or not through the MCU. A metering mutual inductor is arranged between the first contact and the live wire output end. The circuit has the advantages that a detection signal is changed into a current sampling analog signal from a logic level signal; and the collected current information is converted into the corresponding load condition, and a conclusion is given after the load condition is compared with a preset current threshold, so that whether the short circuit condition exists or not can be accurately judged according to the detected current.

Description

technical field [0001] The invention relates to the field of charging piles, in particular to an output short circuit detection circuit and method of an AC charging pile. Background technique [0002] The function of the charging pile is similar to the refueling machine in the gas station. It can be fixed on the ground or wall, and installed in public buildings (public buildings, shopping malls, public parking lots, etc.) and residential area parking lots or charging stations. Charge all models of electric vehicles. The input end of the charging pile is directly connected to the AC grid, and the output end is equipped with a charging plug for charging the electric vehicle. Charging piles are currently divided into AC charging piles and DC charging piles. Among them, AC charging piles are relatively common. After the contact of the relay, the charging pile is started to charge the electric vehicle, but if the output of the AC charging pile is short-circuited, if the contact...

AI Technical Summary

Problems solved by technology

[0004] However, the existing detection circuit judges the open circuit or short circuit state of the AC charging pile by the state of the output. Introduced into the isolation part of the product, resulting in the loss of some or all functions of the product, which may also bring greater risks

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