Voltage regulator

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

An experimental confirmation of automatic threshold voltage convergence in a flash memory using alternating word-line voltage pulses

Abstract: A flash memory using the alternating word-line voltage pulses is experimentally studied. Relations between pulse count and the threshold voltages of the cell are obtained. An automatic threshold voltage convergence was confirmed by the relation, and the threshold voltage is successfully controlled by the word-line pulse voltage. An application to a multi-level flash memory is proposed.

Improved Design and Control of FBSM MMC With Boosted AC Voltage and Reduced DC Capacitance

Abstract: Reducing the capacitance of submodules (SM) and handling short-circuit faults in HVdc systems are crucial for economical and reliable operation of modular multilevel converters (MMC). This paper proposes an SM capacitance reduction method for full-bridge submodule (FBSM)-MMC, which combines circulating current injection and ac voltage boosting. An optimized circulating current control method considering the limitation of fixed semiconductor current rating is introduced. By adding second-harmonic voltage to the reference arm voltage, the capacitor voltage ripple can be controlled to be a targeted value under all operating conditions. To further decrease the SM capacitor voltage ripples, the negative voltage state of FBSM is fully utilized to boost the ac voltage under fixed dc voltage with the modulation index up to 1.414. Consequently, the capacitance requirement for ac voltage boosting FBSM-MMC can be significantly reduced as compared to the conventional FBSM-MMC. Experimental results confirm the feasibility and validity of the proposed SM capacitance reduction method.

Universal USB power supply unit

Abstract: The present invention relates to a includes a USB port connector and a charging connector. The USB port connector is used to plug into the jack of the USB port while the charging connector is used to plug into the jack of the electronic products to be charged. The current flowing into the USB port connector will then pass through an automatic voltage regulator. Disposed within a housing of the automatic voltage regulator is a DC voltage transformer which transforms the DC voltage (5V) coming from the USB port to the required voltage supplied to a power/signal connecting jack. Provided within the DC voltage transformer is furthermore a feedback control voltage output circuit which compares the feedback voltage signal of the power/signal connecting jack and enable the DC voltage transformer to output a preset voltage. The charging connector is fitted with a power cord which includes a power/signal connecting connector to fit the power/signal connecting jack. Moreover, a required voltage parameter is preset within the charging connector.

Device for supplying voltage in a motor vehicle including two batteries and having improved reliability

Abstract: A device for supplying voltage in a motor vehicle is described in which there is at least one generator that can furnish an generator-speed-dependent output voltage without voltage regulation. The at least one generator is preferably a three-phase alternator with a plurality of stator windings whose electrical connections are switchable at predetermined generator speeds by a control unit to provide the generator-speed dependent output voltage. In a following power control unit, this generator speed-dependent voltage is rectified by means of at least one controlled rectifier bridge and via assigned voltage converters is converted into a plurality of directly voltages of different magnitude. These direct voltages are supplied to the individual on-board electrical system components via electronic vehicle body power control system units. By optimal-efficiency triggering of the controlled rectifier bridges and additional safety and/or emergency provisions, the functional capability and power capability of the voltage supply unit are assured.

A particle swarm optimization for reactive power and voltage control in electric power systems considering voltage security assessment

Abstract: This paper presents a particle swarm optimization (PSO) for reactive power and voltage control (Volt/Var Control: VVC) considering voltage security assessment (VSA). VVC can be formulated as a mixed-integer nonlinear optimization problem (MINLP). The proposed method expands the original PSO to handle a MINLP and determines an on-line VVC strategy with continuous and discrete control variables such as automatic voltage regulator (AVR) operating values of generators, tap positions of on-load tap changer (OLTC) of transformers, and the number of pieces of reactive power compensation equipment. The feasibility of the proposed method is demonstrated and compared with reactive tabu search (RTS) and the enumeration method on practical power system models with promising results.