Voltage regulator

About: Voltage regulator is a research topic. Over the lifetime, 33536 publications have been published within this topic receiving 350859 citations.

An Adjustable DC Link Voltage-Based Control of Multifunctional Grid Interfaced Solar PV System

Abstract: This paper presents a grid supported solar energy conversion system with an adjustable dc link voltage for common point of interconnection (CP) voltage variations. A two-stage circuit topology is proposed, wherein the first stage is a boost converter, which serves for maximum power point tracking, and the second stage is a grid tied voltage source converter (VSC), which not only feeds extracted solar photovoltaic (PV) energy into the three-phase distribution system but also serves for harmonics mitigation, reactive power compensation, and grid current balancing. An interweaved double-frequency second-order generalized integrator-based control algorithm is proposed for control of this multifunctional VSC, which possesses the feature of good steady-state performance along with fast dynamic response even under sudden load changes at CPI. Moreover, a feed-forward term for the solar PV contribution is used to enhance the dynamic response for climatic changes and CPI voltage variation. An adjustable dc link voltage structure is used to accommodate CPI voltage variation, which helps in reduction of losses in the power circuit. To implement adjustable dc link voltage structure, the reference dc link voltage is adjusted with variation in CPI voltage in real time. A proportional–integral controller is used to regulate dc link voltage to set reference value. A wide range of experimental results are shown to demonstrate the features of the proposed system. The total harmonic distortion of grid current has been found well under IEEE-519 standard even under nonlinear loads at CPI.

Real-Time Operation and Harmonic Analysis of Isolated and Non-Isolated Hybrid DC Microgrid

Abstract: In this paper, the real-time operation and the harmonic analysis of isolated and nonisolated dc microgrid are investigated. The microgrid features hybrid energy sources with various loading schemes. This hybrid dc microgrid was supplied by an internal generator and the ac utility grid. A supercapacitor bank functions by acting as a power buffer to satisfy the high power requirements of the dc microgrid. In order to properly manage the energy and prevent the ac grid power pulsation, a current-voltage control technique based on master-slave control concept is proposed. In this technique, the supercapacitor bank operates as the master and controls the dc bus voltage. The other converters are working in current control mode to share the required power. The controllers of the converters are equipped with hysteresis voltage control, which monitors the entire supercapacitor bank. Additionally, an analog hysteresis voltage protection circuit board was designed and implemented to protect the supercapacitor cells from overvoltages that can occur due to uneven charge distribution during the fast charging processes. The protection circuit, which was developed and built here, was experimentally tested, and its error was analyzed. Various operating modes based on different power sharing patterns were defined. The experimental test was carried out for both galvanically isolated and nonisolated dc grid systems. The results show that the proposed energy management algorithm properly shares power and control the voltage. In addition, depending on the power sharing pattern, the isolation of the dc microgrid significantly affects the harmonic content of the current.

Voltage regulator for charging generator

Abstract: A voltage regulator for a charging generator is disclosed which comprises an a.c. generator having armature windings and a field winding, and a battery which receives the rectified output of the a.c. generator and is charged by the same. The voltage regulator regulates the output voltage of the a.c. generator by controlling the current flowing through the field winding. To prevent the output voltage of the a.c. generator from becoming a high voltage when a connecting wire connecting the rectified output of the a.c. generator to the battery is broken, the regulator also includes an abnormality detection means which compares the rectified output of the a.c. generator with the battery voltage and detects the abnormality when both voltages are different by more than a predetermined value. This arrangement makes it possible to detect the abnormality at the point of time where the output voltage of the a.c. generator is not yet very high.

Power-supply controller of computer

Abstract: The power-supply controller of a computer can minimize power-consumption as shown in the following description. The operation mode will convert to a sleep-mode reducing the power-consumption below a constant voltage if there is no input to operate a computer system for a predetermined period of time. If the condition of no input for operating a computer system persists, the power supply controller cuts off the power-supply once again. In order to achieve this object, this invention is composed of a power-supply, a power-controller, and a power-mode-controller. The power-supply includes a first rectifier that converts an AC voltage to a DC voltage, a DC/AC converter which converts a DC voltage into an AC voltage, a switching mechanism which outputs a pulse signal used to operate the DC/AC converter, a second rectifier which converts to a DC voltage from an AC voltage received from the DC/AC converter, and a driver which provides an operation voltage to operate the switching mechanism. The power-controller outputs a power-supply signal used to change from the sleep-mode into a power-off mode if there is no input for a predetermined period during the sleep-mode, and which outputs a power-supply signal to change from the power-off mode into a resume-mode if there is an input. The power-mode-controller also includes a power-mode control circuit that varies the output from the power-controller and varies an operation voltage to operate the switching mechanism and a charger which charges a battery with AC voltage and provides the power-controller with a power-supply.

Intelligent battery charging system

Abstract: The present invention is a battery charging system that provides automaticoltage selection, short circuit protection, and delayed output to prevent arcing or pitting. A second embodiment of the invention provides a homing beacon which transmits a signal so that a battery powered mobile robot may home in on and contact the invention to charge its battery. The invention includes electric terminals isolated from one another. One terminal is grounded and the other has a voltage applied to it through a resistor connected to the output of a DC power supply. A voltage scaler is connected between the resistor and the hot terminal. An On/Off controller and a voltage mode selector sense the voltage provided at the output of the voltage scaler. The On/Off controller provides an output whenever Va