This work presents a control algorithm which incorporates a Reference Model Robust Adaptive Controller (RM RAC) and a Linear Quadratic Regulator based on Kalman Filtering (LQRKF ) to obtain a high performance and robust control system. The adaptive portion of the controller deals with system uncertainties, while the optimum scheme, aided by a Kalman Filter, is designed to deal with harmonically related system disturbances. A proof of stability is presented in addition to a numerical example of the combined RM RAC-LQRKF controller to show the effectiveness of this new control approach.
This paper presents a design procedure for a Discrete-Time Robust Model Reference Adaptive Control (DRMRAC) applied to a three-phase four-wire shunt Active Power Filter (APF). The first step when designing the controller is to obtain a representative model for the plant. The theoretical basis for the DRMRAC, considers a parametric model which comprises a modeled part of reduced order, whose parameters are allowed to lie in a predefined range, and a multiplicative and/or additive terms describing the unmodeled dynamics. These dynamics pose a level of uncertainty for the plant, and reflect the difficult in describing the plant behavior, usually at high frequencies. The adaptive law is used to compensate the parametric variation of the plant and the control strategy is robust with respect to such unmodeled dynamics. The plant model, design procedures, main constraints and experimental results are presented.
This paper explores the space vector modulation for voltage fed converters with multiple parallel coupled legs. The proposed modulation strategy allows the synthesis of multilevel equivalent PWM voltage patterns with reduced total harmonic distortion. In addition, thanks to the use of virtual vectors concept, it is possible to establish the voltage limits required to ensure equal current sharing between adjacent legs, avoiding saturation of the coupled inductors. Furthermore the developed modulation approach provides a degree of freedom to select switching sequences that minimizes the inner high frequency leg current ripple. The proposed space vector modulation is demonstrated for a single phase converter, however it can be easy generalized for three phase counterpart. Simulation results are presented to support the developed analysis demonstrating the very good performance of the proposed modulation technique.
This paper proposes a tuning method for a linear quadratic regulator (LQR) and its application to Un interruptible Power Supplies (UPS). A performance index is established based on the desired behavior of system variables, such as maximum values permitted on the states and control law saturation. The tuning method is based on the Q and R weighting matrices, which relate the energy of the state variables involved on the process. From this index it is possible to find an optimal point to reach the required performance. The design procedure is exemplified with an output voltage control of an Un interruptible Power Supply and dynamic results are presented.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.