Voltage-equalizing and power-equalizing control method for multi-module cascade solid-state transformer

• Main Authors: GOU WEI, SHI JIANJIANG
• Format: Patent
• Language: Chinese; English
• Published: 15.12.2010
• Subjects: APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC,OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWERSUPPLY SYSTEMS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTINGELECTRIC POWER; CONTROL OR REGULATION THEREOF; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUTPOWER; 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; 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

The invention discloses a voltage-equalizing and power-equalizing control method for a multi-module cascade solid-state transformer (SST). An SST power main circuit part applied in the method comprises an input stage, an intermediate stage and an output stage, wherein a common duty ratio control policy based on single-phase d-q vector control is adopted in the input stage so as to realize the unit power factor of an input end of an electric network; a control policy based on voltage feedforward and voltage feedback is introduced for each module in the intermediate stage, the voltage feedforward is used as a reference of the voltage feedback, and an error between the voltage feedforward and the voltage feedback is used as a reference of inner current loop of the module after being output by a voltage PI adjuster. The two control policies of the front stage and the intermediate stage interact so as to realize the functions of voltage and power equalization of each SST module, electrical network side unit power