Switching circuit and photovoltaic air-conditioning system

Abstract

The invention relates to the technical field of switch control, in particular to a switch circuit and a photovoltaic air conditioning system. A first input end of a switch detection sub-circuit of theswitch circuit collects a first electrical parameter output by a semiconductor switch sub-circuit, and a second input end of the switch detection sub-circuit collects a second electrical parameter ofan external circuit. The switch detection sub-circuit determines the working state of the semiconductor switch sub-circuit according to the first electrical parameter and the second electrical parameter, and if the working state is abnormal, the control end of the external circuit controls the output end of the external circuit to stop outputting current. According to the technical scheme provided by the invention, the semiconductor switch is used for replacing a relay, whether the relay is adhered or not does not need to be judged, the problem that the relay cannot be disconnected due to adhesion and incapability of detection in a working state is also avoided, and the control complexity is reduced; the fault position can be quickly determined once a fault occurs; therefore, rapid and targeted maintenance processing is realized, and the control reliability is improved.

Description

technical field [0001] The invention relates to the technical field of switch control, in particular to a switch circuit and a photovoltaic air-conditioning system. Background technique [0002] Relays are electronic control devices that are widely used. However, in the process of long-term use, the strong electric contacts of the relay are prone to adhesion and cannot be disconnected in time and reliably, which brings many unstable and uncontrollable factors. In order to avoid the occurrence of unstable factors caused by strong electric contact adhesion of the relay, it is necessary to set up another relay detection circuit to detect the working state of the relay. [0003] For example, currently in photovoltaic air conditioning systems, relays are used as grid-side switches in the market. figure 1 Shown is a kind of relay detection circuit commonly used at present. Its control logic is to first control the relay RLY1 to close, keep the relay RLY2 off, and obtain the abs...

AI Technical Summary

Problems solved by technology

[0005] In view of this, the object of the present invention is to provide a switch circuit and a photovoltaic air-conditioning system to overcome the problem of low reliability of the current relay combined with the relay fault detection circuit

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