Abstract: The analysed results of both voltage regulation and current-harmonic suppression of a self-excited induction generator (SEIG), under unbalanced and/or nonlinear loading conditions using a current-controlled voltage source inverter (CC-VSI) are presented. A hybrid induction-machine model based on the three-phase a-b-c and the d-q frames of reference is employed to describe the dynamic performance of the studied system. The three-phase a-b-c induction-machine model is employed to derive dynamic equations of the SEIG under nonlinear loading conditions. The synchronously rotating reference frame based on a d-q axis model is used to decompose three-phase load currents into active and reactive power currents. The three-phase a-b-c stator voltages of the SEIG and the DC bus voltage of the inverter are simultaneously controlled by a proportional-integral (PI) voltage controller and a harmonic compensator. The simulated results show that the performance of the SEIG under unbalanced and/or nonlinear loading conditions has been effectively improved by the proposed compensating scheme.

Abstract: Regulation of load voltage in single-phase applications is becoming an important issue for critical loads. This paper presents a novel high-performance single-phase voltage regulator which has a common arm between the rectifier and inverter, and adopts an appropriate switching strategy. The proposed voltage regulator employs six switches and can be implemented by only one three-phase inverter module. The proposed voltage regulator has the capability of delivering sinusoidal input current with unity power factor, good output voltage regulation, and bidirectional power flow. For these purposes, a fully digital controller is designed and implemented using a TMS320F240 digital signal processor. In addition, a novel low-cost AC capacitor is also presented. This type of capacitor requires two DC capacitors and two diodes, enabling low-cost and compact manufacturing. Consequently, the complete voltage regulator system, which is mainly suitable for an uninterruptible power supply as well as reactive or nonlinear loads, can be constructed compactly and inexpensively. Experimental results are presented to verify the feasibility of the proposed voltage regulator system.

Abstract: A voltage converter including a transformer having a primary winding connected in series with a switch for cutting-up a supply voltage and having a secondary winding associated with a capacitor providing a D.C. low voltage, and a self-oscillating control circuit of the switch for detecting the end of the demagnetization of an auxiliary winding of the transformer, to turn the switch on, and for detecting the current in the on-state switch to turn it off when this current reaches a reference point. The reference point is made variable according to the voltage across the auxiliary winding.

Abstract: The device has a number of photovoltaic solar modules (10a-n) whose rated power fluctuates depending on parameters such as solar intensity, module temperature, solar technology and aging, and D.C. converters (20a-n) connected in parallel on the output side and to a central D.C./A.C. converter (40) that converts the intermediate D.C. voltage from the converters into a sinusoidal voltage of defined frequency. Each solar module is electrically connected to an individual D.C. voltage converter that transforms the module output D.C. voltage into a significantly higher intermediate D.C. voltage, so that the solar modules are decoupled by their individual D.C. voltage converters.

Abstract: A voltage positioning technique allows a power supply controller to more fully exploit active voltage positioning as a way of maintaining supply voltage within the limits defined for an associated electrical load. The supply voltage is allowed to “droop” as a function of load current. Droop may be implemented in linear proportion to load current, or as a discrete droop function once load current exceeds a given threshold. In either case, the droop circuitry of the supply controller implements a bounding function that establishes an accurately known maximum droop voltage magnitude. This maximum droop voltage limit establishes a reliable lower limit for the supply voltage independent of increasing load current. This accurately set lower bound for the droop voltage enables the controller to more aggressively position the supply voltage at the lower voltage limit of the load, which minimizes voltage overshoot and load power consumption.

Abstract: The present invention provides an off-time modulation in PWM controller to increase the switching period for saving power consumption in the light load and no load conditions. The off-time modulation is achieved by keeping the charge current as a constant and moderating the discharge current of the saw-tooth-signal generator of the PWM controller. Decreasing the discharge current increases the switching period. A feedback voltage, which is derived from the voltage feedback loop, is taken as an index. The discharge current is modulated to be a function of the feedback voltage. A threshold voltage defines the level of the light load condition. The differential of the feedback voltage and the threshold voltage is converted to a current, which is then amplified and turned into the discharge current. A limiter clamps the maximum discharge current to decide the switching period in normal load and full load conditions and determines the dead time of PWM signal. Once the decrement of feedback voltage is close to the threshold voltage, the discharge current will decrease and switching period will be expanded continuously. When the feedback voltage is lower than the threshold voltage, a minimum discharge current decides the maximum switching period. Keeping the maximum on-time as the constant and increasing the switching period by increasing the off-time prevent the magnetic components, such as inductors and transformer, from being saturated.

Abstract: A CPU operating within a low power state has its core voltage controlled to be at a nominal level or a reduced level When the CPU is active it draws power A CPU voltage controller maintains the CPU core voltage at the nominal level to meet the fluctuating power needs of the CPU When the power drawn from the CPU becomes constant (ie, the CPU power needs are being met, perhaps with a ‘cushion’), the CPU voltage controller reduces the core voltage to a reduced level The CPU core voltage remains at the reduced level until increased power needs are anticipated One method for anticipating increased power needs is to monitor PCI bus arbitration lines

Abstract: A plurality of the voltage sources may be selectively connectable in a variety of different arrangements using a switch array whose connections are determined by a programmable controller. For example, a desired output voltage may be automatically provided by altering the connections between the voltage sources to achieve the desired voltage. A programmable controller may determine how to connect the voltage sources to achieve the desired output voltage.

Abstract: An output voltage regulation system allows independent output regulation of multi-output dc-dc switched-mode power converters. The channel resistance of MOSFET synchronous output rectifiers are controlled to obtain the voltage drop required to keep the respective output between predetermined limits concurrent with wide excursions in output load. A typical circuit has a transformer with an input winding coupled to a dc source. A transformer has at least a first and second output winding. A switched-mode regulator means samples a portion of the first output voltage and provides at least a first pulse-width modulated drive voltage having a first state and a second state to a first input semiconductor switch control terminal. The drive voltage first state turns the input semiconductor switch on and the drive voltage second state turns the input semiconductor switch off. The switched-mode regulator means is further characterized to adjust the ratio of the switch's on time to the switch's off time to control the first output voltage to remain within a predetermined range that is proportional to a precision reference voltage. A gate drive means is responsive to at least the first pulse-width modulated drive voltage for providing a first gate drive signal having a peak voltage swing to the synchronous rectifier control terminal. A control means samples a portion of the second dc output voltage and controls the peak voltage swing of the first gate drive signal to control the second output voltage to remain within a predetermined range.

Abstract: This system includes a transformer separable/detachable between a primary winding and a secondary winding, and a capacitor connected parallel to the secondary winding of the above-mentioned transformer, and supplies a high-frequency AC voltage to the primary winding of the transformer to generate an induced voltage in the secondary winding of the transformer, and transmits the electrical power to a load in non-contact manner. The voltage supplied to the load is constant and the flowing current varies. The power may be supplied to a different kind of a load with a constant voltage. Taking as a first condition a fact that at the time of a maximum load, the time of the reversal of the voltage polarity of the above-mentioned primary winding substantially coincides with the time when an oscillating voltage of the above-mentioned capacitor reaches a maximum or minimum value, and taking as a second condition a fact that at the time of a minimum load, the time of the reversal of the voltage polarity of the above-mentioned primary winding substantially coincides with the time when the oscillating voltage of the above-mentioned capacitor completes one cycle, the above-mentioned capacitor is set so that the capacity value satisfies simultaneously the above-mentioned first and second conditions. This allows the load voltage to be made constant in a load current range from a minimum to a maximum without requiring a feedback circuit.

Abstract: A voltage regulator is provided for taking an input voltage and providing a multiple of output voltages of differing voltage values. The voltage regulator includes a power switch and an inductor for providing inductor current to various output nodes. Control switches and a decision logic block are used to regulate the flow of inductor current to the output nodes, in accordance with predetermined values stored in the decision logic block. In one exemplary arrangement, the voltage regulator may provide a multiple of positive and negative voltage outputs. In another arrangement, the voltage regulator may provide a multiple of positive or negative voltage outputs or both.

Abstract: The present invention is directed to an active converter system for a permanent magnetic turbogenerator. A system in accordance with an embodiment of the present invention includes a DC voltage link and a first active converter including a connection for inputting or outputting a three-phase AC voltage to or from, respectively, an AC voltage source, another connection for inputting or outputting a DC voltage from or to said DC voltage link, and at least six selectively switchable first IGBTs, wherein selective switching of the first IGBTs results in a boosted DC voltage. The system further includes a second active converter including a connection for inputting or outputting a three-phase AC voltage to or from, respectively, a permanent magnetic generator, another connection for inputting or outputting a DC voltage to or from said DC voltage link, and at least six selectively switchable second IGBTs, wherein the second active converter is capable of boosting said DC voltage.

Abstract: The invention provides a frequency modulation for a PWM controller to reduce the switching frequency in the light load and no load conditions. The frequency modulation is achieved by moderating the trip-point voltage of the oscillator. Increasing the trip-point voltage reduces the switching frequency. A feedback voltage, which is derived from the voltage feedback loop, is taken as the reference. The sense voltage in the current sense input of the PWM controller represents the information of primary current of the transformer. A sampled voltage is sampled from sense voltage during the PWM signal is turn-off. The trip-point voltage is the function of the feedback voltage and the sampled voltage. A threshold voltage is the sum of the sampled voltage and a constant voltage that define the level for light load condition. Once the feedback voltage is lower than the threshold voltage, the trip-point voltage will increase and switching frequency will reduce. The frequency modulation in the PWM controller can reduce the power consumption of the power supply in light load and no load conditions.

Abstract: Conventionally, the speed of a capacitor run single-phase induction motor is controlled by using an AC voltage controller (generally a triac) between the supply voltage and the motor. This letter proposes a new scheme, in which the triac is inserted in series with the main winding, while the motor auxiliary winding remains directly connected across the supply voltage. The experimental results indicate the superiority of the new method suggested in this letter.

Abstract: An electrical power distribution system includes permanent magnet generator, and an ac regulator. The ac regulator includes an inverter shunt-connected to the permanent magnet generator, and an inverter control for causing the inverter to regulate voltage at output terminals of the generator by providing reactive power (either leading or lagging) that circulates between the inverter and the generator.

Abstract: A single-phase bi-directional AC/DC converter based on neutral point diode clamped configuration is proposed to draw a clean sinusoidal line current with nearly unity input power factor and to achieve DC bus voltage regulation. Based on the neutral point diode clamped scheme, the voltage stress of the power devices is clamped to half DC bus voltage instead of full DC link voltage in the conventional half and full bridge PWM rectifier. The line current command tracking, voltage regulation and balanced neutral point voltage are performed by the inner loop current controller, the outer loop voltage controller and voltage balance compensator, respectively. To generate a three-level PWM pattern on the AC terminal of the AC/DC converter, a region detector of the mains voltage is employed. The effectiveness of the proposed control scheme is confirmed by the experimental results.

Abstract: A telematics communication system ( 100 ) receives an input supply voltage (Vin) ( 122 ) from a battery ( 102 ) charged by an alternator ( 101 ) in an automotive vehicle. The telematics communication system ( 100 ) includes a transceiver ( 104 ) having a transmitter ( 107 ) and a variable delta voltage tracking regulator (VDVTR) ( 109 ). The VDVTR ( 109 ) provides a regulated output supply voltage (Vout) ( 124 ) to a power amplifier ( 114 ) in the transmitter ( 107 ) responsive to the input supply voltage ( 122 ) and a regulator control voltage (TX_EN) ( 123 ). Unfortunately, the alternator ( 101 ) generates alternator whine noise ( 405 ) that appears on the input supply voltage ( 122 ) and, in turn, appears on the regulated output supply voltage (Vout) ( 124 ). The VDVTR ( 109 ) has a first operating stage and a second operating stage, each controlled by a bias circuit (R 1 , R 2 and R 3 ), and a third operating stage, controlled by a voltage limiting circuit (D 1 ). The first operating stage of the bias circuit sets the regulated output supply voltage (Vout) ( 124 ) to be equal to the input supply voltage ( 122 ) (Vout=Vin) when the input supply voltage ( 122 ) is less than or equal to a first predetermined voltage (Vmin), responsive to the regulator control voltage ( 123 ) and the input supply voltage ( 122 ), to permit the presence of the alternator whine noise ( 405 ) on the regulated output supply voltage (Vout) ( 124 ) while giving operational priority to the transmit power output level of the transmitter ( 107 ). The second operating stage of the bias circuit sets the regulated output supply voltage (Vout) ( 124 ) to be equal to a predetermined function of the input supply voltage (Vin) ( 122 ) (Vout=mVin+b) when the input supply voltage ( 122 ) is between the first predetermined voltage (Vmin) and a second predetermined voltage (Vmax), greater than the first predetermined voltage (Vmin), responsive to the regulator control voltage ( 123 ) and the input supply voltage ( 122 ), to create an increasing voltage delta ( 404 ) between the input supply voltage ( 122 ) and the regulated output supply voltage (Vout) ( 124 ), thereby reducing the alternator whine noise ( 404 ) on the regulated output supply voltage (Vout) ( 124 ) while continuing to meet operational requirements of the transmit power output level of the transmitter ( 107 ). The third operating stage sets the regulated output supply voltage (Vout) ( 124 ) to be equal to a maximum predetermined voltage (Vmax) (Vout=Vmax) when the regulated output supply voltage (Vout) ( 124 ) is greater than or equal to the second predetermined voltage (Vmax), responsive to the regulator control voltage ( 123 ) and the input supply voltage ( 122 ) to limit the voltage supplied to the power amplifier 114.

Abstract: The invention relates to programmable voltage regulator that programmably provides a desired operating voltage to a power pin based upon operating voltage configuration data. The programmable voltage regulator includes an operating voltage configuration data decoder arranged to decode the operating voltage configuration data. The programmable voltage regulator also includes a programmable voltage down converter connected to the operating voltage configuration data decoder. The programmable voltage down converter uses the decoded operating voltage configuration data to convert the first voltage to the desired operating voltage which is then output to the power pin.

Abstract: A converter station (STN 1, STN 2 ) having a voltage source converter (CON 1, CON 2 ) is coupled between a direct current link (W 1, W 2 ) and an alternating current network (N 1, N 2 ) in a high voltage direct current transmission system. A control system (CTRL 1, CTRL 2 ) for the converter station has means for control of active power flow (P) between the direct current link and the alternating current network by influencing the phase displacement (γ) between a bus voltage (UL 1, UL 2, UL) in the alternating current network and a bridge voltage (UV 1, UV 2, UV) of the voltage source converter. The control system comprises detection means ( 48 ) for generation of a phase change order signal (PCO) in response to an indication of an abnormal voltage condition at the direct current link, and means ( 49 ) for influencing the phase position of the bridge voltage in response to said phase change order signal, so as to ensure that the phase displacement between the bridge voltage and the bus voltage will result in an active power flow from the direct current link to the alternating current network.

Abstract: Small-signal models of quasi-resonant (QR) power converters with current-mode control, obtained by state-space averaging, suggest that a linear feedback law can be used to improve the dynamic response of the converter. This can be done by seeking a gain vector that places the closed-loop poles at the locations desired. Instead, the authors use optimal control techniques, together with those small-signal models, to design a robust voltage controller for QR converters that overcomes some uncertainties that may corrupt the results obtained by classical design methods. As an example, they present the design procedure and experimental results for a 1 MHz QR-ZVS buck converter with a linear quadratic regulator (LQR).

Abstract: A semiconductor controller device to control the operation of a semiconductor memory device. The controller device includes a first output driver coupled to a first output terminal, and a second output driver coupled to a second output terminal. In addition, the controller device includes a voltage divider, coupled between the first and second output terminals, to generate a control voltage based on a voltage level present on the first output terminal and a voltage level present on the second output terminal. In addition, the controller device also includes a comparator, coupled to the voltage divider, to compare the control voltage with a reference voltage, wherein an amount of voltage swing of the first output driver is adjusted based on the comparison between the control voltage and the reference voltage.

Abstract: Part I of this paper proposes a novel mains voltage proportional input current control concept eliminating the multiplication of the output voltage controller output and the mains AC phase voltages for the derivation of mains phase current reference values of a three phase/level/switch PWM (VIENNA) rectifier system. Furthermore, the concept features a low input current ripple amplitude as, e.g., achieved for space vector modulation, a low amplitude of the 3rd harmonic of the current flowing into the output voltage center point and a wide range of modulation. The practical realization of the analog control concept as well as experimental results for application with a 5 kW prototype of the PWM rectifier are presented. Furthermore, a control scheme which relies only on the absolute values of the input phase currents and a modified control scheme which does not require information about the mains phase voltages and therefore is ideally suited as a basis for the development of an integrated control circuit for three phase power factor correction is presented.

Abstract: A semiconductor memory device including an array of memory cells The memory device includes a first output driver coupled to a first output terminal, and a second output driver coupled to a second output terminal The memory device further includes a voltage divider coupled between the first and second output terminals, to generate a control voltage based on a voltage level present on the first output terminal and a voltage level present on the second output terminal The memory device further includes a comparator, coupled to the voltage divider, to compare the control voltage with a reference voltage, wherein an amount of voltage swing of the first output driver is adjusted based on the comparison between the control voltage and the reference voltage

Abstract: An apparatus comprising a circuit configured to generate an output voltage having a magnitude greater than a supply voltage, where the output voltage is (i) a positive high voltage when a first input is in a first state and a second input is in a second state and (ii) a negative high voltage when the first input is in the second state and the second input is in the first state.

Abstract: A single-cycle response pulse width modulator comprising a single error integrating amplifier (U1). The error integrator output is compared to zero to set a flip-flop (FF1). A ramp voltage (VRAMP) is compared to the reference voltage (Vref) to reset the flip-flop (FF1). The ramp voltage (VRAMP) is generated by combination of a resistor (RT) and a current mirror circuit (Q1, Q3, Q4, Q5) coupled to the supply voltage (VP) and charging a capacitor (CT). The flip-flop (FF1) when reset discharges the capacitor (CT). Corrective circuits compensate for delay times in components to maintain substantially constant switching frequency and low distortion in the output voltage. The controller is capable of outputting a predictive triggering signal for associated class-N amplifiers.

Abstract: The preferred embodiment describes a regulating device ( 400 ) that regulates current flow through a thermoelectric cooler (TEC) ( 420 ) with higher power efficiency than conventional regulating methods. The regulating device includes a voltage controller ( 415 ) that receives an input voltage from a comparator ( 435 ) that has determined whether there has been a change in temperature surrounding a temperature sensitive device, such as a laser, by way of a thermistor ( 425 ). The controller ( 415 ) then controls two pulse width modulated (PWM) synchronous rectifiers ( 405, 410 ). The combination of the controller ( 415 ) and the synchronous rectifiers ( 405, 410 ) improves the power efficiency of the regulating device ( 400 ). Each PWM synchronous rectifier ( 405, 410 ) includes two field effect transistors (FETs) that supply substantially a constant current flow through the TEC ( 420 ) to either heat or cool a control surface ( 430 ).

Abstract: This paper presents complete analysis of induction generators linked to the network through transistorized AC voltage controller. Three different control strategies are investigated, and various performance characteristics have been computed. The generator performance has been determined with the help of a novel abcdq circuit model. The model possesses the advantage of both the dq and direct phase models.

Abstract: A voltage level converter includes a static voltage level converter and a split-level output circuit coupled to the static voltage-level converter. In another embodiment, the voltage-level converter includes a static voltage level-converter, a first transistor, and a second transistor. The static voltage-level converter includes an input node, a first pull-up node, a second pull-up node, an inverter output node, and an output node. The first transistor is coupled to the input node and the first pull-up node. The second transistor is coupled to the second pull-up node and the inverter output node.

Abstract: The nonvolatile memory sensing circuit includes a main cell part and at least one reference cell part, including a main cell array having a plurality of main cells to which a word line driving signal is applied respectively, a plurality of main cell switches receiving a plurality of main cell selection signals YG 0 to YGn which switch to select one of the main cells wherein the main cell switches are connected to the main cell array in series, a main cell bit line voltage controller maintaining drain voltage to a fixed level by receiving program bias voltage PRBIAS, a main cell path transistor connected between an output of the main cell bit line voltage controller and internal power supply voltage wherein the main cell path transistor outputting a state of the main cell, and at least one sense amplifier producing a comparison output SAOUT by receiving at least one reference voltage RDREF and an output SENSE of the main cell path transistor, and wherein the reference cell part further comprises a program reference cell part and read reference cell part which share a voltage controlling means regulating drain or source voltage to a predetermined level and wherein the reference cell part produces reference voltage RDREF of fixed level.