Title:
CIRCUIT AND METHOD FOR DETECTING INSULATION RESISTANCE OF PHOTOVOLTAIC ARRAY TO GROUND, AND PHOTOVOLTAIC INVERTER
Document Type and Number:
WIPO Patent Application WO/2020/253876
Kind Code:
A1
Abstract:
Disclosed is a circuit for detecting the insulation resistance of a photovoltaic array to ground. The circuit comprises a first switch tube Q1 and a second switch tube Q2 in an inverter circuit connected to a photovoltaic array, two sense resistors R1, R2, and an operational amplifier, wherein the midpoint of the first switch tube Q1 and the second switch tube Q2 is connected to an inverting input end of the operational amplifier by means of the sense resistor R2; a non-inverting input end of the operational amplifier is connected to a ground end, namely, a PE end, by means of the sense resistor R1; and an output end of the operational amplifier forms a voltage detection end. A detection method used by the detection circuit comprises the following steps: step 1, switching off a first switch tube Q1 and switching on a second switch tube Q2, and giving a first formula; step 2, switching on the first switch tube Q1 and switching off the second switch tube Q2, and giving a second formula; and step 3, solving, according to the first formula and the second formula, an insulation resistance value of a photovoltaic array to ground. A photovoltaic inverter comprises an inverter circuit, a detection circuit and an inverting control chip. The detection circuit can save on the space and cost of an inverter, reduce the failure probability of the inverter, and reduce the operation amount of an inverting control chip.
Inventors:
LIU SONG (CN)
HUANG MIN (CN)
FANG GANG (CN)
LU JINJUN (CN)
JIANG FENG (CN)
YUAN HONG (CN)
HUANG MIN (CN)
FANG GANG (CN)
LU JINJUN (CN)
JIANG FENG (CN)
YUAN HONG (CN)
Application Number:
PCT/CN2020/097483
Publication Date:
December 24, 2020
Filing Date:
June 22, 2020
Export Citation:
Assignee:
JIANGSU GOODWE POWER SUPPLY TECH CO LTD (CN)
International Classes:
G01R27/02; H02S50/00
Foreign References:
| CN110412352A | 2019-11-05 | |||
| CN102298091A | 2011-12-28 | |||
| CN203941235U | 2014-11-12 | |||
| CN202994907U | 2013-06-12 | |||
| CN104977471A | 2015-10-14 | |||
| CN104702208A | 2015-06-10 | |||
| CN105004979A | 2015-10-28 | |||
| CN108490258A | 2018-09-04 | |||
| CN208000342U | 2018-10-23 | |||
| US9024646B2 | 2015-05-05 |
Other References:
See also references of EP 3988947A4
Attorney, Agent or Firm:
SUZHOU CREATOR PATENT AND TRADEMARK AGENCY, LTD (CN)
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