Explicit Model Predictive Control In Power Electronics And Power Systems

To the dynamical systems subject to constraints on states and inputs, either in the control theory or in the control engineering, the optimal control problem is very meaningful. Model Predictive Control (MPC) could provide a very powerful framework to deal with this type of problem and has thus received great interest by both industry and academia. But the big drawback of the MPC based on the on-line optimization is the relatively formidable on-line computational effort, which limits its applicability to relatively slow and/or small problems.The multi-parametric programming is introduced into the solving of constrained optimal control problems, which could construct the explicit model predictive control (eMPC). The eMPC is solved off-line for all possible initial states. The solution then takes the form of a piecewise affine state feedback law which can be easily implemented on-line by the use of lookup tables. This scheme greatly decreases the cost of applying MPC to industrial systems and makes the on-line computation of the optimal input sequence significantly simpler. In this paper, the principal tasks as follows:1. Based on a great deal of literature, generic conditions which guarantee stability and feasibility of MPC are summarized. And how Lyapunov functions which guarantee asymptotic stability can be constructed for autonomous piecewise-affine (PWA) systems are introduced.2. To linear time-invariant (LTI) system, the equality of finite and infinite optimal control is reformulated, and a novel method of compute robust low complexity eMPC controllers is studied. Then based the algorithm, a single and double inverted pendulum system are simulated. The results show that the eMPC in this paper is effective on inverted pendulum system.3. In this paper, the possibility of constructing stabilizing controller is studied. Based on the dynamic programming, the computational method of robust low complexity eMPC controller is studied.4. According to the example of the synchronous step-down DC-DC converter, the eMPC controller of DC-DC converter is studied. Using the method named v-resolution to set up discrete-time hybrid model and then transform to PWA form. The result of simulation shows that the eMPC controller is viable, and effective on the system, also can guarantee asymptotic stability.5. Based on the non-linear model of power system, the explicit model predictive control of power system is studied. The non-linear model of power system can be divided into two parts and then get a MLD form of hybrid model. The simulation results show that the load voltage can be stabilized by an eMPC controller using only nominal control moves, and regulation of the controller is very simple and intuitive.