Photovoltaic inverter leak current regulation inhibiting method and device

Abstract

The invention discloses a photovoltaic inverter leak current regulation inhibiting method and device. The method comprises the following steps: determining a predetermined control mode according to the working state of a photovoltaic system, wherein the control mode comprises a dominant control quantity of a bus voltage and an injection form of a common-mode voltage; and controlling the common-mode current in the photovoltaic system according to the determined control mode. The invention further provides a photovoltaic inverter leak current regulation inhibiting device comprising a control module and an executing module. On the premise of realizing the closed-loop control of the common-mode leak current, the realization of the technical scheme in the invention improves the utilization rate of the bus voltage and improves the system efficiency by using the common-mode leak current as a control target and referring to the working state of the system when the common-mode leak current is less than the safety requirement.

Description

technical field [0001] Embodiments of the present invention relate to the field of communication technology, and more specifically, to a method and device for adjusting and suppressing leakage current of a photovoltaic inverter. Background technique [0002] In the prior art, due to the existence of the parasitic capacitance of the photovoltaic panel to the ground and the effect of the common-mode voltage of the inverter, a common-mode leakage current to the ground will be generated, such as figure 1 i shown in cm , the traditional pulse width modulation (Pulse Width Modulation in English, hereinafter referred to as PWM) improves bus utilization by injecting common-mode voltage, but does not take common-mode leakage current as the control target, so the output PWM common-mode voltage is relatively low. If it is large, it will cause the problem of leakage current to ground in photovoltaics or other fields with high requirements for common-mode voltage of frequency converters...

AI Technical Summary

Problems solved by technology

[0003] In the process of realizing the present invention, the inventor found that there is a technology in the prior art that detects the leakage current waveform, analyzes and processes it to generate a compensation current that is equal in magnitude and opposite to the common mode leakage current, injects the compensation current into the circuit and passes Superimposed and canceled with the common-mode leakage current to suppress and eliminate the common-mode leakage current, the control process of this existing technology is complicated in practical applications, and it is easy to generate disturbances. Therefore, the effect of improving system efficiency is not ideal

Images