Detection circuit of inverter's insulation resistance to ground

Abstract

The invention provides a detection circuit for insulation resistors to ground of an inverter. The detection circuit is connected between a positive electrode and a negative electrode of a direct current power source. The number of the insulation resistors to the ground is two; one ends of the insulation resistors to the ground are connected with the positive electrode and the negative electrode; the other ends of the insulation resistors to the ground are connected with the ground. The detection circuit comprises a first resistor with one end connected with the positive electrode and the other end connected with the ground, a third resistor with one end connected with the negative electrode, a second electrode with one end connected with the other end of the third electrode and the other end connected with the ground, a sixth resistor with one end connected with the positive electrode, a seventh resistor with one end connected with the other end of the sixth resistor and the other end connected with the negative electrode, a detection adjusting circuit and a data processing circuit; the detection adjusting circuit and the data processing circuit which are connected with a connecting point of the second resistor and the third resistor and a connected point of the sixth resistor and the seventh resistor are used for obtaining first sampling voltage and second sampling voltage. The detection circuit for the insulation resistors to the ground of the inverter has the advantages of saving computing resource of the inverter, reducing requirement for detection accuracy, meanwhile enabling direct current insulation anomaly to the ground to be detected and avoiding unnecessary economic losses.

Description

technical field [0001] The present invention relates to a resistance detection circuit, in particular, the present invention relates to a detection circuit of the ground insulation resistance of an inverter. Background technique [0002] At present, for the detection of the insulation resistance of the DC input end of the inverter to ground, please refer to figure 1 shown, figure 1 It is a schematic diagram of a detection circuit of the insulation resistance of a DC input end of an inverter to ground in the prior art. Among them, R+ is the insulation resistance to ground of the positive electrode PV+ of the photovoltaic cell (not shown), and R- is the insulation resistance to the ground of the negative electrode PV- of the photovoltaic cell. The first to sixth given resistors R1, R2, R3, R4, R5 and R6 are connected between the positive electrode PV+ of the photovoltaic cell and the ground, and between the negative electrode PV- of the photovoltaic cell and the ground. [...

AI Technical Summary

Problems solved by technology

[0004] However, when the computing power of the inverter is limited or the detection accuracy is limited, it is necessary to use a chip with more powerful computing power and a detection circuit with higher precision.

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