Fan grid-connected sub-synchronous oscillation suppression and high-frequency harmonic suppression method based on virtual impedance

• Main Authors: DENG JUN, ZHOU QIAN, XIA NAN, LIU YAO, YIN JUNGANG, ZHENG TIANYUE, WANG JIANBO, PENG SHUTAO, ZHANG HAIJING, LI SHUPENG
• Format: Patent
• Language: Chinese; English
• Published: 16.04.2021
• 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 fan grid-connected sub-synchronous oscillation suppression and high-frequency harmonic suppression method based on virtual impedance. Aiming at the problem of sub-synchronous oscillation possibly caused by fan grid connection under the background of a complex power grid, an impedance analysis method is adopted for modeling or measuring to obtain a fan converter impedance model and a power grid impedance model, different virtual impedance links are designed at different frequency bands and added into a fan control system, so that the effects of sub-synchronous oscillation suppression and higher harmonic suppression are achieved, and the grid-connected stability of the fan is improved. The fan grid-connected sub-synchronous oscillation and high-frequency harmonic suppression method provided by the invention comprises the following steps of: performing impedance modeling on a fan according to a hardware structure and a control system structure of the fan to obtain fan impedance Zinv; ca