Title:
IMPACT-CURRENT-FREE GRID-CONNECTED CONTROL METHOD FOR THREE-PHASE PHOTOVOLTAIC GRID-CONNECTED INVERTER
Document Type and Number:
WIPO Patent Application WO/2019/174331
Kind Code:
A1
Abstract:
An impact-current-free grid-connected control method for a three-phase photovoltaic grid-connected inverter. The method comprises: acquiring a line voltage at a power grid side and a line voltage at an inverted side of a three-phase photovoltaic grid-connected inverter before the three-phase photovoltaic grid-connected inverter is switched on, so as to obtain a drive pulse required for the three-phase photovoltaic grid-connected inverter to be subjected to power grid voltage feedforward current inner ring decoupling control; and when (1) a difference value between a D-axis voltage component at the power grid side and a D-axis voltage component at the inverted side of the three-phase photovoltaic grid-connected inverter is less than a pre-set D-axis threshold value, and (2) a difference value between a Q-axis voltage component at the power grid side and a Q-axis voltage component at the inverted side is less than a pre-set Q-axis threshold value, and the duration is greater than a set first time threshold value, switching on a grid-side relay of the three-phase photovoltaic grid-connected inverter to complete switching-on grid connection. The control method solves a series of problems that the service life of a component is shortened due to the presence of a grid-connected impact current, the leakage current is excessive when a power grid is impacted, etc., and is compatible with triangular and star-like power grids.
Inventors:
XU YAFEI (CN)
HUANG MIN (CN)
FANG GANG (CN)
LU JINJUN (CN)
HUANG MIN (CN)
FANG GANG (CN)
LU JINJUN (CN)
Application Number:
PCT/CN2018/120027
Publication Date:
September 19, 2019
Filing Date:
December 10, 2018
Export Citation:
Assignee:
JIANGSU GOODWE POWER SUPPLY TECH CO LTD (CN)
International Classes:
H02J3/38
Foreign References:
| CN108365628A | 2018-08-03 | |||
| CN104218605A | 2014-12-17 | |||
| CN102723727A | 2012-10-10 | |||
| CN102780414A | 2012-11-14 | |||
| CN106655272A | 2017-05-10 | |||
| CN105811751A | 2016-07-27 | |||
| CN106655270A | 2017-05-10 |
Attorney, Agent or Firm:
SUZHOU CREATOR PATENT AND TRADEMARK AGENCY, LTD (CN)
Download PDF: