DC voltage control strategy of cascaded H-bridge APF with unbalanced grid voltage

作者：Huang, Hai Hong; Wang, Chao; Wang, Hai Xin

来源：Electric Machines and Control, 2018, 22(11): 37-45.

DOI：10.15938/j.emc.2018.11.005

• Active power Filter
• Cascaded H-bridge
• DC voltage
• Negative voltage
• Unbalanced grid voltages

There is a problem of DC voltage balancing in the cascaded H-bridge topology. The unbalanced grid voltage leads to the unbalanced DC voltage which influences the steady operation of the APF system. To solve this problem, the three levels voltage control strategy which is suitable for the unbalanced grid voltage condition was proposed. A power exchange model was built to find out what makes the DC voltage between phases and among one phase unbalanced. The fundamental active current was used to keep the balance of total DC voltage. By adding a negative voltage in the AC side to redistribute the power of three phase, the DC voltage of three phase balanced is balanced. By appending a voltage vector in the AC side, voltage balancing among one phase is achieved.Finally, the simulation and experiment results prove the validity of this three level control strategy.

• 出版日期2018
• 单位合肥工业大学