Photovoltaic inverter and protection device of photovoltaic inverter

Abstract

The invention discloses a protection device of a photovoltaic inverter. The protection device comprises a voltage detection circuit, a driving control circuit and a control circuit; under the condition that the photovoltaic inverter is in the high-voltage input state, the voltage detection circuit outputs a first control signal to the driving control circuit, a by-pass switch is controlled by the driving control circuit to be switched on, and a photovoltaic module supplies power to a bus through the by-pass switch. Under the condition that the direct-current side of the photovoltaic inverter is short-circuited, the voltage detection circuit outputs a second control signal to the driving control circuit, the by-pass switch is controlled by the driving control circuit to be switched off, a large current is prevented from flowing through the by-pass switch, short-circuit protection on the by-pass switch is achieved, the by-pass switch is prevented from being damaged, and the reliability of the photovoltaic inverter is accordingly improved. In addition, the control circuit can control the driving control circuit to switch off the by-pass switch. The invention further discloses the photovoltaic inverter.

Description

technical field [0001] The invention belongs to the technical field of photovoltaic power generation, and in particular relates to a photovoltaic inverter and a protection device thereof. Background technique [0002] Photovoltaic inverter is an important device in photovoltaic power generation system. In order to improve the conversion efficiency of the photovoltaic inverter, other switching devices with smaller conduction losses can be used to replace traditional diodes. Since the conduction loss of these switching devices is smaller, the conversion efficiency of the photovoltaic inverter can be improved by using the switching devices in the photovoltaic inverter. In implementation, the bypass switch may use a field effect transistor, a relay or other switching devices. [0003] figure 1 A structure of a photovoltaic inverter is shown, which includes a step-up DC / DC (direct current / direct current) converter 1, a DC / AC (direct current / alternating current) converter 2, a ...

AI Technical Summary

Problems solved by technology

[0004] However, when the photovoltaic inverter uses bypass switches, if these bypass switches have the characteristics of reverse conduction, for example, the bypass switch uses field effect transistors or relays, when a short circuit occurs on the DC side of the photovoltaic inverter, the busbar The electric energy stored in capacitor C is discharged by short circuit, and a large current will flow through the bypass switch, which will cause the bypass switch to be damaged, thereby reducing the reliability of the photovoltaic inverter

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