The Auto Disturbance Rejection PID Control For Power

With the development of high-parameter and large-capacity power, thenonlinearity, time varying, time-delay, disturbance and coupling are increasinglyremarkable. For the safety, stability and high-performance of power, one key is toimprove the automatic control level. This paper mainly deals with the autodisturbance rejection PID control and its application to power system. Especially, wepay attention to parameter uncertainties, non-minimum phase, time-delay andnonlinear multivariable coupling, separately. So the paper can be included as follows.Firstly, design an auto disturbance rejection PID controller for parameteruncertain plant. Based on Kharitonov Theorem and Generalization of KharitonovTheorem, the closed-loop system stabilization is proved. A set of controllercoefficients guaranteeing the robust stabilization for interval plant family comes forth.To seek an optimized controller, we define the objective weighted function betweenrelative integral of the time weighted absolute error and control input. If the objectiveweighted value is minimum, the controller parameter is optimized. Results show thatthis controller could improve the robustly stable performance to uncertainties.Secondly, develop an auto disturbance rejection PID control method fornonlinear and non-minimum phase system. A kind of dynamic extension is necessaryintroduced to augment the original system to a higher dimensional state space. Withthe assumption that the zero dynamics of the extended system is stable, the autodisturbance rejection PID controller is designed. This method is applied tohydroturbine generator set. The controller designed under the rigid water-hammermodel, is extended to control the elastic water-hammer system. Digital simulationtests make it clear that this controller is very effective to the hydroturbine generatorset. The method not only improves large disturbance stability of the power system,but also possesses the function to set up resynchronization after the stability in thesense of the power system lost.Then, propose an auto disturbance rejection PID controller for high-order ortime-delay system. The plant can be mathematically described by first-order plusdead-time model. A two-order observer is used to compensate the dynamicalunknown factors. Adding the classical feedback theory, we obtain the autodisturbance rejection PID controller with four parameters. Three parameter tuningformulas result from the Z-N tuning rule. The last free parameter is properly chosenup to the PID control dynamics based on Z-N ruling parameters. This method isapplied to the boiler superheated steam temperature control system. From thefindings, it is clear that this controller for high-order or time-delay system hasgood dynamical performance, adaptability and robustness.Finally, introduce an auto disturbance rejection PID controller to MIMOcoupling multivariable process. For the boiler-turbine plant, the auto disturbancerejection PID controller is improved to auto disturbance rejection PI controller.Without compensating matrix, this control system completely decouples, andachieves robust stabilization over a wide operating large.As one can see from simulations, the auto disturbance rejection PID controlmethod achieves zero steady-state-error tracking, little overshoot, robustly adaptiveperformance.