Voltage regulator

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

SMES Based Dynamic Voltage Restorer for Voltage Fluctuations Compensation

Abstract: This paper presents a superconducting magnetic energy storage (SMES) based dynamic voltage restorer (DVR) to protect consumers from the grid voltage fluctuations. Due to the characteristic of high energy density and quick response, a superconducting magnet is selected as the energy storage unit to improve the compensation capability of DVR. This paper analyses the operation principle of the SMES based DVR, and designs the DVR output voltage control method. The control system mainly consists of two parts, the PWM converter controller and the DC/DC chopper controller. The PWM converter controller adopts double-loop control strategy, with an inner current regulator and an outer voltage controller. Combining the coordinated control of DC/DC chopper, the DVR can regulate output voltage accurately and quickly to compensate the system voltage fluctuations. Using MATLAB SIMULINK, the models of the SMES based DVR is established, and the simulation tests are performed to evaluate the system performance.

Light emitting diode array driving apparatus

Abstract: There is provided a LED array driving apparatus for driving a light emitting array having a plurality of LEDs connected to one another, including: a DC-DC converting part; a current/voltage detecting part detecting a magnitude of a first current flowing through a switching transistor of the DC-DC current converting part to correspondingly output a first current detection voltage, detecting a magnitude of a both-end voltage of the LED array to correspondingly output a LED array detection voltage, and detecting a magnitude of a current flowing through the LED array to correspondingly output a second current detection voltage; and a constant current controlling part controlling an on/off duty of the switching transistor according to the magnitude of the first current detection voltage, the second current detection voltage and the LED array detection voltage detected by the current/voltage detecting part.

An Enumeration-Based Model Predictive Control Strategy for the Cascaded H-Bridge Multilevel Rectifier

Abstract: In this paper, a model predictive control strategy is adapted to the cascaded H-bridge (CHB) multilevel rectifier. The proposed control scheme aims to keep the sinusoidal input current in phase with the supply voltage and to achieve independent voltage regulation of the H-bridge cells. To do so, the switches are directly manipulated without the need of a modulator. Furthermore, since all the possible switching combinations are taken into account, the controller exhibits favorable performance not only under nominal conditions but also under asymmetrical voltage potentials and unbalanced loads. Finally, a short horizon is employed in order to ensure robustness; this way, the required computational effort remains reasonable, making it possible to implement the algorithm in a real-time system. Experimental results obtained from a two-cell CHB rectifier are presented in order to demonstrate the performance of the proposed approach.

Dynamic headroom control for lcd driver

Abstract: An LED driver controller comprises a voltage regulator for controlling an output voltage to a top of a plurality of LED strings responsive to at least a reference voltage. A plurality of first circuitries each associated with a node at a bottom of each of the plurality of LED strings compares a voltage at the bottom of each of the plurality of LED strings with a high reference voltage and a low reference voltage. Control logic generates a first control signal when the voltage at the bottom of each node of the plurality of LED strings exceeds the high reference voltage and generates a second control signal when the voltage at least one of node of the plurality of LED strings falls below the low reference voltage. Second circuitry responsive to the first control signal and the second control signal generates the reference voltage. The reference voltage is controlled to cause the voltage at the bottom of the lowest voltage node of the plurality of LED strings to remain between the high reference voltage and the low reference voltage.

Low voltage techniques

Abstract: Techniques for the design of linear ICs, capable of operating from a single nickel-cadmium cell (> 1.1V) will be presented. Results can be achieved without compromising performance or operation at higher voltages. Emphasis will be on micropower, though not at the expense of output drive.