1. School of Electrical Engineering, Northeast Electric Power University, Jilin 132012, China; 2. Electric Power Research Institute of State Grid East Inner Mongolia Electric Power Company Limited, Hohhot 010020, China
Based on the nonlinear relationship between the voltage and current of the DC link, a piecewise affine model(PWA)of voltage source converter based high-voltage direct-current(VSC-HVDC)system is developed. According to the characteristics of fast dynamic change of PWA system with state and input constraints, this paper makes up for the shortcomings of model predictive control(MPC)causing slowed-down system response and degraded real-time performance. Explicit model predictive control(EMPC)combined with off-line calculation and on-line analysis is used to transform repeated online rolling optimization calculation into a simple table lookup process. The output trajectory of the VSC-HVDC system by means of expected interval tracking deviation and adding the variable soft constraints is optimized. Simulation results show that the explicit model predictive controller has good dynamic performance and steady performance, while able to suppress fluctuations of output trajectory. Compared with the MPC, the dynamic response of EMPC is faster, and the real-time of EMPC is stronger.
|||ZHANG Hong, LIU Xu, ZHANG Siyu, et al. Design for Explicit Model Predictive Control Based on Expected Interval Tracking and Variable Soft Constraint of VSC-HVDC System[J]. Automation of Electric Power Systems,2017,41(14):182-189. DOI:10.7500/AEPS20161130003|