Modern control techniques of electrical drives (EDs) use robust control algorithms. One of such algorithms is variable structure control (VSC) with sliding mode (SM). SM control needs more information on the controlled plant than the conventional PI(D) control. Valid mathematical model of the controlled plant is necessary for the SM controller design. Generalized mathematical model of two-phase electrical machine and its adaptation to direct current (DC) and induction motor (IM) are given in this paper, employed in the cascade control structure. Also, the basic SM control theory and discrete-time controller design approach, developed by the authors, are given. Finally, experimentally realized examples of speed and position control of DC and IM are given as an illustration of the efficiency of the promoted EDs controller design via discrete-time VSC.

Abstract The paper proposes a discrete-time sliding mode controller for single input linear dynamical systems, under requirements of the fast response without overshoot and strong robustness to matched disturbances. The system input saturation is imposed during the design due to inevitable limitations of most actuators. The system disturbances are compensated by employing nonlinear estimation by integrating the signum of the sliding variable. Hence, the proposed control structure may be regarded as a super-twisting-like algorithm. The designed system stability is analyzed as well as the sliding manifold convergence conditions are derived using a discrete-time model of the system in the δ-domain. The results obtained theoretically have been verified by computer simulations.

Distribution network power flow (DNPF) is a core application of distribution management system (DMS). Two methods to implement fast DNPF are using Newton-Raphson (NR) approach and current iteration (CI) approach. In distribution systems with high penetration of renewable energy sources both methods must be able to model PV nodes correctly and efficiently. This paper explores implementations of NR DNPF and CI DNPF, their execution time and performance in networks with numerous distributed generators.

This paper proposes a control method for multi-input linear systems that provides the closed-loop system dynamics of an arbitrary order having a specified feasible spectrum of poles. By appropriate selection of auxiliary outputs, the system is decoupled into a set of subsystems. The number of these subsystems is equal to the number of control inputs. The desired dynamic of the considered system is achieved using higher order sliding mode, where the sliding mode of appropriate order is realized in each subsystem. The proposed control approach is illustrated by a simulation example.

This paper describes the transient characteristics and control of the output DC voltage of a stand-alone switched reluctance generator (SRG). A mathematical model of switched reluctance machine (SRM) is developed and implemented in Matlab/Simulink software. The mathematical model is verified experimentally. The robust controller based on the discrete-time sliding mode control (DT-SMC) technique is proposed for the SRG voltage control. The robustness is achieved using the disturbance estimator. The proposed control technique was implemented through simulations on a three phase 12/8-pole SRG with a variable speed and load. The proposed DT-SMC based controller is compared with a standard PI controller. Obtained results show the effectiveness and quality of DT-SMC based voltage control technique for the SRG.

This paper presents a new dead-beat control design for a class of multi-input linear time-invariant continuous-time controllable systems. The system is controlled using multi-rate sampled data. First step in design is to obtain the controllability index vector. Using elements of this vector known as controllability indices, the state feedback matrix is computed applying higher order sliding mode control approach. The number of sliding variables is equal to the number of control inputs. Obtained control annihilates system state in a minimal number of sampling periods which is equal to the maximal value of controllability indices. Since, the dead-beat control has poor robustness, a disturbance compensation is designed. In this paper, the compensation control is equal to the negative value of the disturbance estimate. The estimate is obtained using the equivalent control approach, while the compensation sampling period is not the same as the deadbeat control sampling period. The control is formed as the dead-beat control term and the compensation control which suppressed disturbance effects. The sampling period of compensation control is generally smaller than the control sampling period. Properties of the proposed control system are demonstrated on a simulation example.

This paper describes the transient performance and voltage regulation of a stand-alone self-excited induction generator (SEIG). All characteristics are calculated with a ftux-based mathematical model of the induction machine in the stationary reference frame appropriate for the stand-alone SEIG. The generator model and the control system model are developed using Matlab/Simulink. A presented generator model takes into account significant effects of magnetic saturation on the SEIG performance. The simulation was performed by loading the SEIG with a variable resistive load. Some of the computed characteristics are compared with experimental results. Both uncontrolled and controlled response of the SEIG to load variations were analyzed. It is shown that voltage variations can be reduced by using voltage source inverter and terminal voltage controller.