Insulation detection circuit, inverter and insulation detection method thereof

Abstract

An insulation detection circuit comprises a first resistor, a second resistor, a third resistor and a first switch, wherein one terminal of the first resistor is connected with a first input positive terminal; the other terminal of the first resistor is respectively connected with one terminal of the first switch and one terminal of the second resistor; the other terminal of the first switch is grounded; the other terminal of the second resistor is connected with an input negative terminal through the third resistor, so that the insulation detection circuit can be really isolated from the ground, thereby avoiding the production of leakage currents; and the precision of the insulation detection circuit is relatively high. An inverter comprises a main body and the insulation detection circuit, wherein the insulation detection circuit is connected in parallel to an input terminal of the inverter, so that the first switch of the insulation detection circuit can be turned off after the work of the insulation detection circuit is completed, thereby really isolating the insulation detection circuit from the ground, avoiding the production of the leakage currents and guaranteeing normal work of the inverter.

Description

technical field [0001] The invention belongs to the field of insulation safety, and in particular relates to an insulation detection circuit, an inverter and an insulation detection method thereof. Background technique [0002] Existing photovoltaic cell modules need to be placed outdoors that can receive sunlight for a long time, so with the use of time and sudden changes in external weather, it is easy to cause the insulation of the output end of the photovoltaic cell module to the ground to change, or due to the inverter Unforeseen faults in itself have changed the insulation of the input terminal to the ground, thereby affecting the leakage current of the photovoltaic cell module or the inverter to the ground, and the connection between the ground and the chassis, thereby affecting the safety of the inverter and the inverter. The performance of the inverter itself, so the inverter needs to conduct a reconnaissance of the ground impedance before each normal operation. ...

AI Technical Summary

Problems solved by technology

[0004] In order to solve the technical problem that the existing insulation detection circuit does not isolate the earth, thus generating leakage current and the insulation detection accuracy is not high, the invention provides an insulation detection circuit, an inverter and its insulation detection circuit which isolates the earth and has high insulation detection accuracy Detection method

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