Voltage regulator

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

Led driver with feedback calibration

Abstract: Power management in a light emitting diode (LED) system having a plurality of LED strings is disclosed. A voltage source provides an output voltage to drive a plurality of LED strings. An LED driver implements a feedback mechanism to monitor the tail voltages of the active LED strings to identify the minimum tail voltage and adjust the output voltage of the voltage source based on the lowest tail voltage. A loop calibration module of the LED driver calibrates the feedback mechanism of the LED driver based on a relationship between a digital code value used to generate a particular output voltage and another digital code value generated based on the minimum tail voltage resulting from the particular output voltage.

Charge pump with symmetrical +V and -V outputs

Abstract: Charge pump circuitry is implemented using a voltage shifting technique to generate a symmetrical bipolar voltage. The symmetrical bipolar voltage charge pump power supply can be fabricated as an integrated circuit on a single substrate, and can be integrated with various interface circuits to provide symmetrical bipolar voltage thereto. The charge pump includes voltage shifting circuitry which generates an increased output voltage of a negative polarity and an increased output voltage of a positive polarity. The shifting circuitry is responsive to an internal oscillator which triggers charge accumulation and voltage shifting. Neither output voltage is generated from the other output voltage. Rather, the negative and positive supply voltages are each generated, in substantially the same manner, by charge transfer effected by the voltage shifting circuitry in response to triggering by the internal oscillator. Additional circuitry can be fabricated on a single substrate in combination with the presently disclosed charge pump to effect the optimum utilization of circuit board area while minimizing power consumption.

Distribution feeder voltage regulation control

Abstract: Step voltage regulators are the work horse of distribution feeders for maintaining the voltage at every customer's meter to be within the ANSI standards. A step voltage regulator can be viewed as a tap changing autotransformer. This paper will apply a model of the step voltage regulator. The IEEE 13 Node Test Feeders will be used to demonstrate how the regulator is controlled in order to maintain the desired voltage for full load, light load and future load conditions. The coordination of step voltage regulators with shunt capacitors will be included.

Space vector pulse-width modulation algorithm and DC-side voltage control strategy of three-phase four-switch active power filters

Abstract: A space vector pulse-width modulation (SVPWM) algorithm and a DC-side voltage control strategy for three-phase four-switch shunt active power filters are proposed. The basic principle of three-phase four-switch inverters to output three-phase balanced voltages is investigated in detail. Based on an advanced coordinate transformation, the proposed algorithm ensures basic voltage vectors to be right on the coordinate axes of αβ-coordinate system, which has the advantages of less computation and higher accuracy than the traditional. It synthesises zero vectors by equalising the duration time of two basic voltage vectors, which are equivalent in amplitude and opposite in phase, to simplify control logic and decrease harmonics of output voltages. To stabilise the DC bus voltage and balance the DC-side capacitor voltages, a DC-side voltage control strategy is presented. The former objective is obtained by controlling the active partition of the output currents, and the latter one by adapting the direct partition of phase C output current. An overall control method combining the proposed SVPWM algorithm with the DC-side voltage control strategy is presented. Experimental results have shown the validity and feasibility of the proposed algorithm and strategy.