Method and system for seamless switching of micro-grid system

• Main Authors: LIU ZHIQIANG, SU WEIFENG, SUN GUANGXING, GOU RUIFENG, ZHANG DONGSHENG, WEI SANMIN, LI XIA
• Format: Patent
• Language: Chinese; English
• Published: 26.03.2014
• Subjects: CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTINGELECTRIC POWER; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; ELECTRICITY; GENERATION; SYSTEMS FOR STORING ELECTRIC ENERGY

The invention discloses a method and a system for seamless switching of a micro-grid system. The method comprises the following steps that: a first voltage-acquisition module acquires the voltage value of each phase on the grid side connected to the module; PCS determines the electricity losing ratio of the current voltage value of each phase to the standard value, and counts the sum value of the times when the electricity losing ratio of the voltage value of each phase is below the predetermined value; the PCS judges that the sum value is greater than the threshold, and executes VF switching, at the same time triggers off the PCC switch between the grid connected to the switch and the micro-grid. The switching way from the grid-connected mode to the off-grid mode has small impact on the electric current, and is capable of achieving a smooth switching from the grid-connected mode to the off-grid mode.