Topic
Open-loop controller
About: Open-loop controller is a research topic. Over the lifetime, 16148 publications have been published within this topic receiving 224014 citations. The topic is also known as: non-feedback controller & open-loop control law.
Papers published on a yearly basis
Papers
More filters
TL;DR: In this article, an integral sliding mode current controller with an integral switching surface for switched reluctance motor (SRM) drives is designed based on the equivalent circuit model of SRM, including the magnetic saturation and mutual coupling.
Abstract: A fixed-switching-frequency model-based sliding mode current controller with an integral switching surface for switched reluctance motor (SRM) drives is presented in this paper. Based on the equivalent circuit model of SRM, including the magnetic saturation and mutual coupling, an integral sliding mode current controller is designed. The stability of sliding mode controller is analyzed in two scenarios: 1) one with known motor parameters and 2) the other with bounded modeling error. In order to analyze the robustness of the sliding mode controller, the motor controller parameter constraints are derived and the stability analysis is demonstrated by considering motor parameter modeling errors. The sliding mode controller is validated by both simulation and experimental results with a 2.3-kW, 6000-r/min, three-phase 12/8 SRM over the wide speed range in both linear and magnetic saturation regions. Compared to the hysteresis current controller, the sliding mode controller demonstrates comparable transient response and steady-state response in terms of torque ripples, current ripples, root-mean-square error of current and torque. Moreover, the sliding mode controller has some advantages over the hysteresis controller, including constant switching frequency and much lower sampling rate.
89 citations
TL;DR: The proposed control strategy ensures zero steady-state error and improves the performance under hard transients such as load variation, and presents robustness when the APF is operating under unbalanced conditions.
Abstract: Shunt active power filters $(SAPFs) $ implemented without harmonic detection schemes are susceptible to sudden load variations. This paper proposes a robust control strategy to reduce this drawback. In this strategy, the dc-link voltage is regulated by a hybrid control technique combining a standard proportional–integral $PI$ and a sliding-mode $(SM)$ controllers. The $SM$ scheme continuously determines the gains of the $PI$ controller based on the control loop error and its derivative. The chattering due to the $SM$ scheme is reduced by a transition rule that fixes the controller gains when steady-state condition is reached. This controller is termed as dual-sliding-mode-proportional–integral. The phase currents of the power grid are indirectly regulated by double-sequence controllers with two degrees of freedom, where the internal model principle is employed to avoid reference frame transformation. The proposed control strategy ensures zero steady-state error and improves the performance under hard transients such as load variation. Additionally, it presents robustness when the $SAPF$ is operating under unbalanced conditions. Experimental results demonstrate the performance of the proposed control scheme.
89 citations
DOI•
01 Jan 1980TL;DR: In this article, a self-tuning controller that minimises a cost function incorporating system input, output and set-point variations is presented, and adapts it in such a way that the closed loop poles are located on prespecified locations.
Abstract: This paper presents a self-tuning controller that minimises a cost function incorporating system input, output and set-point variations, and adapts it in such a way that the closed-loop poles are located on prespecified locations. The link that exists between the classical control strategy of pole assignment and the suboptimal strategy of the self-tuning controller is demonstrated and made use of to produce a generalised controller which possesses the major advantages of both. The controller combines the robustness of pole assignment with the ease of reference following provided by suboptimal self tuning.
89 citations
Patent•
20 Jul 2004
TL;DR: A synchronous rectifier PWM (SR-PWM) controller controls a MOSFET in response to the value of a secondary current and the status of a synchronous signal for both discontinuous and continuous operation mode as discussed by the authors.
Abstract: A synchronous rectifier PWM (SR-PWM) controller controls a MOSFET in response to the value of a secondary current and the status of a synchronous signal for both discontinuous and continuous operation mode. The secondary current is generated in a secondary circuit and is detected by two threshold-detection terminals of the SR-PWM controller. The SR-PWM controller produces the synchronous signal by detecting a switching signal of the transformer via a detection terminal of the SR-PWM controller. Furthermore, a delay-time is inserted after the MOSFET is turned off and before the next switching cycle starts to ensure a proper operation of the MOSFET. In one embodiment, an equivalent series resistance (ESR) of an output capacitor can be used as a sensor to detect the secondary current. Therefore, no additional current sensor is required and the efficiency can be improved.
89 citations
TL;DR: In this paper, a new nonlinear voltage controller is proposed, which involves the direct feedback linearization (DFL) technique and robust control theory, and the performance of the proposed nonlinear controller in a single machine-infinite bus power system is simulated.
89 citations