Commutation Failure Risk Assessment of Multi-infeed HVDC Transmission Systems

摘要

The multi-infeed HVDC transmission system is widely used in modern smart grid because of the suitability for large-capacity long-distance power transmission. With the successive construction of multi-infeed HVDC systems, the receiving end system's characteristic of “Strong HVDC and Weak AC system” is becoming more and more obvious. The commutation failure of multi-infeed HVDC systems is a significant threat to the stability of the modern smart grid. This paper proposes a commutation failure risk assessment method that considers the HVDC system operation strategy, the reactive power compensation devices and receiving end system structure. The method consists of two aspects for multi-infeed HVDC transmission systems and receiving end system. In the method, the judgment condition is the commutation failure evaluation factor (CFEF) derived from the essence of the commutation failure. Moreover, the CFEF is utilized to derive the evaluation result in the two aspects of risk assessment method. The evaluation result is verified by the simulation of an actual power grid with ultra high voltage (UHV) and extra high voltage (EHV).