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.

Digital Repetitive Control of a Three-Phase Four-Wire Shunt Active Filter

Abstract: Shunt active power filters have been proved as useful elements to correct distorted currents caused by nonlinear loads in power distribution systems. This paper presents an all-digital approach based on a particular repetitive control technique for their control. Specifically, a digital repetitive plug-in controller for odd-harmonic discrete-time periodic references and disturbances is used for the current control loops of the active filter. This approach does not introduce a high gain at those frequencies for which it is not needed and, thus, improves robustness of the controlled system. The active power balance of the whole system is assured by an outer control loop, which is designed from an energy-balancing perspective. The design is performed for a three-phase four-wire shunt active filter with a full-bridge boost topology. Several experimental results are also presented to show the good behavior of the closed-loop system

Controller and expansion unit for controller

Abstract: An extension unit (50, 60 or 70) is connected to the main body (10) of a controller provided with an analogue direction key (12), a digital direction key (14), indicating buttons (20a-20z), indicating levers (22l and 22r), etc. When the unit (50) having a light emitting section (52) is connected to the controller, a cordless controller becomes available. When the unit (60) having a photodetecting section is connected, a gunshot game for shooting enemies on the monitor screen can be played. When the unit (70) having a vibrating section (75) is connected, a realistic gunshot game can be played by vibrating the main body (10). Therefore, a new function can be added to the conventional controller freely without changing the main body (10).

Analysis and design of direct power control (DPC) for a three phase synchronous rectifier via output regulation subspaces

Abstract: In this paper, the authors present a controller that directly regulates the active and instantaneous reactive power in a synchronous three-phase boost-type rectifier. The controller ensures a good regulation of the output voltage, and guarantees the power factor close to one. The controller builds upon the ideas of the well known direct torque control (DTC) for induction motors. In their case, the active and reactive powers replace the torque and flux amplitude used as the controlled outputs in DTC, thus motivating the name DPC-control. They show that a simple modification to the original algorithm makes the selection of the control inputs more accurate. To formalize this technique, they utilize the concept of output regulation subspaces. A modification is added to the basic controller to deal with disturbances such as unbalance and distortion in the source voltage. Finally, the proposed controller was tested both in simulations and experimentally, and illustrative results are presented.

Adaptive Step Size With Adaptive-Perturbation-Frequency Digital MPPT Controller for a Single-Sensor Photovoltaic Solar System

Abstract: This paper presents a load-current-based maximum power point tracking (MPPT) digital controller with an adaptive-step-size and adaptive-perturbation-frequency algorithm. Only one sensor is needed in the controller circuitry since the MPPT controller is only utilizing the load current information. By utilizing a variable step-size algorithm, the speed, accuracy, and efficiency of the PV system MPPT are improved when compared to the fixed step-size load-current-based algorithm. Furthermore, the proposed adaptive algorithm utilizes a novel variable perturbation frequency scheme which further improves the controller speed. The concept and operation of the load-current adaptive-step-size and adaptive-perturbation-frequency MPPT controller are presented, analyzed, and verified by results obtained from a proof-of-concept experimental prototype.