MIXED INITIATIVE AND ANTI-ISLANDING DETECTION METHOD AND SYSTEM

• Main Authors: ZHANG, HUA, SASAN, MOSTAFAEI, WU, BIN, ZHANG, DONGLAI, SOOSAN, BEHESHTI
• Format: Patent
• Language: Chinese; English; French
• Published: 08.05.2014
• Subjects: CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTINGELECTRIC POWER; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; ELECTRICITY; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERATION; MEASURING; MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES; PHYSICS; REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGYGENERATION, TRANSMISSION OR DISTRIBUTION; SYSTEMS FOR STORING ELECTRIC ENERGY; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS; TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINSTCLIMATE CHANGE; TESTING

A mixed initiative and anti-islanding detection method and system. The method comprises the following steps: acquiring the change value ∆ω of the grid frequency in each control period, and acquiring the effect of the change value ∆ω of the grid frequency on the reactive power reference value Q ref by using a positive feedback frequency shift method and through gain processing, the correspondence between the change value ∆Q GCC of the reactive power reference value Q ref in each control period and ∆ω being as follows: ∆Q GCC = pf ∆ω, wherein K pf is the gain in the islanding effect pre-detection; when frequency shift occurs in the change value ∆ω of the grid frequency at 0.1Hz, determining that the islanding phenomenon probably occurs in an inverter, and triggering an initiative islanding detection method to perform further islanding detection; and otherwise, re-acquiring the change value ∆ω of the grid frequency, and performing gain processing on the ∆ω. In this method, only when the islanding effect is found