Analysis of energy efficiency measurement scheme for flexible HVDC transmission system

The composition and analysis of the loss of flexible HVDC transmission system based on modular multilevel converter (MMC) is a great challenge for engineering application. An energy efficiency measurement scheme for flexible HVDC transmission system is proposed in this paper. Firstly, the power losses caused by each energy consumption equipment in flexible HVDC transmission system is analyzed quantitatively. It can be seen that the most of the losses come from the converter valve and connection transformer. After considering energy consumption rate, economy, harmonic influence, the choice of relevant energy efficiency measurement points is then determined. Moreover, the accuracy and the error consistency of measuring device are analyzed according to the error transfer theory. Finally, the feasibility of the scheme will be proved by a typical flexible HVDC transmission system. This scheme provides guidance for the energy efficiency analysis of flexible HVDC transmission system, which is useful for the future applications.