This paper proposes a new robust control method for a wind energy conversion system. The suggested method can damp the deviations in the generator speed because of the penetration of wind speed and load demand fluctuations in the electrical grid. Furthermore, it can overcome the uncertainties of the plant parameters because of load demand fluctuations and the errors of the implementation. The new method has been built based on new simple frequency-domain conditions and the whale optimization algorithm (WOA). This method is utilized to design a robust proportionalintegral-derivative (PID) controller based on the WOA in order to enhance the damping characteristics of the wind energy conversion system. Simulation results confirm the superiority and robustness of the proposed technique against the wind speed fluctuations and the plant parameters uncertainties compared with other meta-heuristic algorithms. KEYWORDS frequency-domain constraints, meta-heuristic algorithms, robust PID controller, wind energy conversion system
| INTRODUCTIONRecently, electrical power generation from renewable energy sources (RES) is considered one of the most promising solutions to overcome the energy problems in the world. Furthermore, renewable energy is clean, and it has a low effect on the environment. So new researches in the power systems are focused on the utilizing of renewable energy in electricity generation. 1,2 Among the RES, wind energy is a more effective renewable energy source, and it can produce high power during the conversion into electrical energy. 3,4 However, wind energy produces fluctuated electrical power because of the fluctuations of the wind speed. In addition, it causes many problems in electrical system operation such as generator speed regulation. 5,6 So the wind turbine (WT) speed and its output power must be regulated. The regulation of the WT speed and the output power is developed by varying the pitch angle of its blades. The WT is connected with a blade pitch control (BPC) to enhance the operation of the wind energy conversion system (WECS), and it ensures the energy production limit against the fluctuations of the wind speed. Furthermore, the BPC preserves the quality of the generated power, and it protects the WT from any damaging because of the high wind speed.In recent years, several control methods are used for the BPC in WECS such as the proportional-integral-derivative (PID) controller, 7,8 statefeedback controller, 9 H 2 /H ∞ control, 10 sliding mode control, 11 fuzzy logic, 12 neural networks, 13 and model predictive control (MPC). 14 Among NOMENCLATURE: P, active power (p.u. MW); Q, reactive power (p.u. MVAR); vto, infinite bus voltage (p.u. /journal/we 391 400 ELSISI
| CONCLUSIONThe tuning of PID controller gains by a novel AI technique named WOA is suggested in this paper. The proposed method is applied to the BPC of a WT in the WECS. In addition, simple frequency-domain conditions are developed based on Hermite-Biehler theorem to ensure the system stability over the plant parameters uncertai...