Hierarchical MPC scheme for the speed governing of PSU with complex conduit system. Issue 2 (9th December 2019)

• Record Type: Journal Article
• Authors: Zheng, Yang; Chen, Qijuan; Xu, Yanhe; Wang, Weiyu; Yan, Donglin; Liu, Wanying
• Is Part Of: IET generation, transmission & distribution. Volume 14:Issue 2(2020)
• Page Start: 316
• Page End: 329
• Publication Date: 2019-12-09
• Subjects: predictive control -- optimisation -- three‐term control -- hydraulic turbines -- servomotors -- power generation control; hierarchical MPC scheme -- speed governing -- PSU -- complex conduit system -- pumped‐storage unit -- frequency modulation sources -- modern power systems -- frequent operation condition conversions -- tight hydraulic couplings -- governing control -- tough work -- proportional–integral–derivative parameter tuning -- transient processes -- hierarchical model predictive control scheme -- CGPC -- classic PID -- upper hierarchy -- MPC controller -- auxiliary optimiser -- optimal PID parameters -- online optimisation -- lower hierarchy -- existing governing equipment -- engineering practise -- distributed‐parameter simulation platform -- hydraulic behaviours -- mechanical dynamic behaviours -- speed tracking -- oscillation damping; Electric power production -- Periodicals; Electric power transmission -- Periodicals; Electric power distribution -- Periodicals; 621.3105
• DOI: 10.1049/iet-gtd.2019.0859
• Languages: English
• ISSNs: 1751-8687

Abstract

Abstract : Pumped‐storage unit (PSU) often acts as the peak and frequency modulation sources in modern power systems. The frequent operation condition conversions and tight hydraulic couplings with conduit system make its governing control a tough work in practise. To overcome the difficulty in the proportional–integral–derivative (PID) parameter tuning during transient processes, a hierarchical model predictive control (MPC) scheme, in which constrained generalised predictive control (CGPC) cooperates with classic PID is proposed. In the upper hierarchy of the MPC controller, CGPC acts as an auxiliary optimiser for the optimal PID parameters through online optimisation, whereas in the lower hierarchy, PID directly steers the movements of servomotor to control the guide vane opening; thus, to match the existing governing equipment in engineering practise. Also, typical constraints on the input/output signals and value ranges of PID parameters are discussed. Simulation experiments are conducted on a non‐linear distributed‐parameter simulation platform. It can precisely reflect hydraulic and mechanical dynamic behaviours of PSU and its conduit system. The results indicate that the proposed hierarchical MPC scheme not only outperforms in speed tracking and oscillation damping, but also attenuate instability phenomena caused by the negative 'S' character in pump turbine.