SIMULATION RESEARCH ON THE GRID CONNECTED GENERATION SYSTEM OF SOLAR THERMAL POWER GENERATION

Objective: To improve the efficiency and stability of the solar thermal power generation system, and promote the optimization and development of solar thermal power generation grid connection. Methods: The working principle of the heat exchanger in the heat storage system is analyzed. Combined with the technological requirements of the system, the mathematical model of the heat exchanger is established by the mechanism modelling method. According to the inherent characteristics and control requirements of the heat storage system, the control schemes are proposed. The control strategies of different control algorithms, such as single-loop control, Smith predictive compensation control, cascade-Smith control, and feed-forward-cascade-Smith control, are designed and adopted. The simulation model is established to obtain step response waveforms of different control systems. The advantages and disadvantages of different control strategies are comprehensively analyzed and compared. Results: After introducing the superheated steam mass-flow disturbance, the error of the single-loop control system increases. After adjusting the system to restore the oscillation state, the system error is high (10.24%). Smith predictive compensation control system fluctuates, with a peak time of 548 seconds and a peak temperature of 366 degrees C. The cascade-Smith control system fluctuates, with a peak time of 620 seconds, a peak temperature of 398 degrees C, and a maximum deviation of 31 degrees C. The feedforward-cascade-Smith control system is disturbed, with a peak time of 606 seconds, a minimum temperature of 347 degrees C, and a maximum deviation of 4 degrees C. Compared with the cascade-Smith control system, the disturbance deviation of the feedforward-cascade-Smith control system is reduced by 87%. Conclusion: The feedforward-cascade-Smith control system proposed has the advantages of strong anti-interference ability, good stability, and small steadystate error, which has a certain significance for the development of concentrating solar power technology.