Photovoltaic inverter leakage current detecting device and method

Abstract

The invention discloses a photovoltaic inverter leakage current detecting device and method. The detecting device comprises a leakage current sampling module and a micro-controller module. The leakage current sampling module comprises a magnet ring, an oscillating circuit, a self-checking circuit, a filtering link and the like and is mainly responsible for sampling leakage current and filtering out interference of oscillation frequency, a microcontroller mainly comprises a small-size, low-price and all-functional STM32F030F4 and surrounding pin circuits thereof, and the microcontroller is responsible for controlling, calculating and correcting of detection of leakage current and information exchange with an external master controller. A whole detecting process is performed in a sequence of power-on handshaking, self-checking, circle detection, abnormal warning and the like. By means of the photovoltaic inverter leakage current detecting device, correcting of proportionality coefficient can be achieved, the same style of leakage current detecting device is applicable to inverters with different capacities, and conveniences are provided for united production of inverter leakage current detecting devices.

Description

technical field [0001] The invention relates to the technical field of power supplies, in particular to a photovoltaic inverter leakage current detection device and method. Background technique [0002] Non-isolated inverters without transformers (high frequency, low frequency) have been valued and sought after by researchers at home and abroad because of their obvious advantages in efficiency, volume, weight, and cost. However, since there is no transformer structure, the photovoltaic system and the power grid have a direct electrical connection, which is likely to cause a large increase in leakage current, that is, common-mode current, and cause serious safety hazards, so leakage current detection must be introduced. [0003] The industry technical standard stipulates that when the average leakage current is 30mA, 60mA, and 100mA, the specified disconnection time is 0.3s, 0.15s, and 0.04s, respectively. Currently, the leakage current detection devices on the market are al...

AI Technical Summary

Problems solved by technology

At present, the leakage current detection devices on the market are all aimed at the leakage current detection of a single product device. Each leakage current detection device can only be applied to a single model, which is not conducive to the unified production of inverters.

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