Entries |
Document | Title | Date |
20090096432 | Loading reduction device and method - An active loading-reduction device is provided for a circuit. The circuit has functional circuitry coupled to a terminal to receive an alternating voltage. The circuit also has an electrostatic discharge protector that is coupled to the terminal. The active loading-reduction device includes active circuitry that is adapted to be coupled to a power supply to provide a reactance to counteract a reactance provided by the electrostatic discharge protector at the terminal of the circuit. | 04-16-2009 |
20090184694 | FLICKER IMPROVEMENT EFFECT EVALUATING SYSTEM - A flicker improvement effect evaluating system evaluates an effect of improvement of voltage flicker in a power system to which a static reactive power compensator is to be introduced. A system voltage operating unit operates a compensation current and a system impedance of the power system, based on actually measured data of system voltage and load current read from a data reading unit. Based on the results of operations and the actually measured data, a not-yet-improved system voltage at present and an improved system voltage attained when the static reactive power compensator is provided on a bus are simulated. By a flicker meter, flicker values of the not-yet-improved system voltage and improved system voltage amplified by an amplifying circuit are measured, and from the flicker values, the rate of improvement attained by the static reactive power compensator is operated. | 07-23-2009 |
20090243561 | METHOD OF POWER FACTOR CORRECTION - A method of power factor correction without using current sensing or a multiplier is disclosed. A generated predictive pulse is used to charge and discharge a PFC inductor in such a way that the current in the PFC inductor has a similar phase angle as the input AC voltage. Each ON portion of the pulse is used for charging while each OFF portion is used for discharging. As the input voltage increases in phase, the predictive pulse gradually increases in ON time duty and the PFC inductor is charged in increasing amount and discharged in decreasing amount per pulse. When peak is reached the duty ratio is reduced each pulse and the PFC inductor current is reduced along with the input AC voltage source until phase angle reaches 180 degrees and the ON time becomes zero. | 10-01-2009 |
20090278512 | APPARATUS, SYSTEM, AND METHOD FOR CONTROLLING A MATCHING NETWORK - An apparatus, system and method are described that enable an impedance of a plasma load to be matched with a power generator. In some embodiments the apparatus includes a power output adapted to apply power that is utilized to energize a plasma; a sensor adapted to sample power applied at the power output so as to obtain power samples; and an impedance control output configured to provide, responsive to the power samples, an impedance-control signal that enables an impedance matching network connected to the output of the power generator and to the impedance control output to match, responsive to the an impedance-control signal, the impedance of the plasma to the operating impedance of the power generator. | 11-12-2009 |
20110089913 | POWER SUPPLY DEVICE - A power supply device includes first and second power factor correctors, and first and second resonant circuits. The first and second power factor correctors are for receiving an alternating current (AC) input voltage, and are driven by first and second driving signals for rectifying the AC input voltage to generate first and second driving voltages, respectively. The first and second resonant circuits are coupled to the first and second power factor correctors for receiving the first and second driving voltages, respectively, and have output sides that are coupled in parallel for outputting an output voltage. The first power factor corrector and the first resonant circuit in combination is parallel-connected to the second power factor corrector and the second resonant circuit in combination | 04-21-2011 |
20110215776 | POWER SUPPLY TRANSIENT RESPONSE IMPROVING - A power factor correcting power supply. The power factor correcting power supply includes a controlled current source for providing electrical power of a regulated current and a regulated voltage to a first output terminal, a voltage comparison current controller, and a control circuit responsive to the current at the output terminal, the control circuit coacting with the voltage comparison current controller to cause the controlled current source to increase or decrease the current at the first output terminal. | 09-08-2011 |
20110254518 | STATIC VAR COMPENSATOR APPARATUS - A one-phase static var compensator apparatus includes a compensator string consisting of a first static var compensator connected serially to a thyristor valve. The compensator string is arranged to be connected on its first end to one phase of a transmission grid of a rated voltage exceeding 69 kV. Moreover, the thyristor valve includes a plurality of thyristors connected serially and the compensator string is arranged to be directly connected to the transmission grid. A corresponding three phase apparatus is also presented. | 10-20-2011 |
20120086413 | REACTIVE CURRENT TRANSFORMER - An apparatus and method for utilizing reactive power in electric power generating facilities. The primary energy source is a reactive power provided by a source of high-frequency, high-voltage electromagnetic oscillations. As a device, the Reactive Current Transformer consists of a high-voltage, high-frequency electromagnetic generator, preferably Tesla Resonant Transformer and of inductive receiving coils, electromagnetically coupled in the absence of a ferromagnetic core, adjusted in resonance with this electromagnetic generator and mounted in any required quantity, close to it. Energy, emitted by the electromagnetic generator, is being transferred to inductive coils. Reactive current induced in the inductive coils can be collected from them and converted to a standard AC voltage for further use by any convenient way, preferably with a help of additional inductive transforming windings, mounted together and electromagnetically coupled with these inductive coils. | 04-12-2012 |
20120268084 | BRIDGELESS POWER FACTOR CORRECTION CIRCUIT - A bridgeless PFC circuit is provided. A low-frequency bridge leg includes a first diode and a second diode connected in series; a three-port network includes a switch tube and an inductor; a lightning and surge protection bridge leg includes a third diode and a fourth diode connected in series; a capacitor is connected between terminals of the low-frequency bridge leg, and between terminals of the lightning and surge protection bridge leg; a common terminal of the first and second diodes is connected to a terminal of an AC power, and a common terminal of the third and fourth diodes is connected to the other terminal; and the three-port network has two ports with the capacitor connected therebetween, and another port connected to the common terminal of the third and fourth diodes. Thus, EMI performance and efficiency can be improved and costs of the whole circuit can be lowered. | 10-25-2012 |
20120326679 | DEVICE FOR OPTIMIZING ENERGY USAGE IN MULTIPHASE AC POWER SOURCE - An energy optimization alternating current power balancing system for a three phase alternating current power source using various configurations of chokes, wire inductors and capacitors connected across and in parallel to each power lines from the alternating current power source. An inductor in the alternating current power-balancing device or system is connected in series to the neutral line of the alternating current power source to create a more balanced power distribution system by improving the power factor and increasing the efficiency of energy consumption in multiphase alternating current power source. | 12-27-2012 |
20130002211 | CONTROLLER, WIND PARK AND CONTROL METHOD - Described is a controller, wherein the controller is adapted: to control a transformation ratio of a park transformer of a wind turbine park including wind turbines connected to a first node. The park transformer is connected between a first node and a second node which is connected to a utility grid to which electric energy produced by the wind turbines is to be delivered. Further a wind park and a control method are described. | 01-03-2013 |
20130033239 | Means of Providing Variable Reactive Load Capability on an Electronic Load - Embodiments of the invention include an electronic load having variable reactive load capability and techniques for controlling and/or modeling a reactive component in a load. The electronic load can include a user interface through which a latency value is received from a user. A delay is created based on the latency value between the time that a variable of the input signal is sensed and the time that a variable of the input signal is driven to a new value, thereby simulating a reactive component in the electronic load based on the created delay. In one example embodiment, the driven variable can be stepped after the created delay to produce an approximation of a capacitive or inductive element. In another example embodiment, the driven variable can be slewed during the delay period using an arbitrary waveform generator, thereby more accurately simulating the reactive component. | 02-07-2013 |
20130234681 | M2LC System and Method for Controlling Same - A modular multilevel converter system. The system includes a plurality of series connected two-terminal M2LC cells arranged into at least two output phase modules. A first one of the output phase modules has an inductance and an effective capacitance associated therewith. The first one of the output phase modules is configured so that a natural resonant frequency of the inductance with the effective capacitance of the first one of the output phase modules is greater than at least one of the following: an operating frequency of the first one of the output phase modules; a switching frequency of the first one of the output phase modules; and a switching frequency of any of the M2LC cells of the first one of the output phase modules. | 09-12-2013 |
20130307495 | METHOD AND APPARATUS TO INCREASE EFFICIENCY IN A POWER FACTOR CORRECTION CIRCUIT - A power factor correction (PFC) controller includes a capacitor, an error amplifier, a switching frequency adjuster, a comparator, and a drive signal generator. The current source generates a current that is representative of an instantaneous input voltage of a PFC converter to charge the capacitor when a power switch of the PFC converter is off. The switching frequency adjuster generates an adjusted error signal in response to an error signal generated by the error amplifier. The comparator compares a voltage on the capacitor with the adjusted error signal to generate a first signal to end an off time of the power switch. The drive signal generator controls switching of the power switch in response to the first signal. The switching frequency adjuster changes the adjusted error signal in response to changes in the error signal to adjust an average switching frequency of the power switch. | 11-21-2013 |
20140097808 | DIGITAL CONTROLLER BASED DETECTION METHODS FOR ADAPTIVE MIXED CONDUCTION MODE POWER FACTOR CORRECTION CIRCUIT - Methods and apparatus for zero current detection and discontinuous conduction mode digital detection for a boost power factor correction converter based on a digital signal processor are disclosed. By effectively using resources in a processor with integrated high-speed comparators, simple detection can be accomplished with cost and performance over alternative detection methods. The methods and apparatus can be employed in an adaptive digital controller for mixed-conduction mode in the converter and can provide for lower total harmonic distortion and greater power factors than a non-adaptive controller. | 04-10-2014 |
20140103888 | METHODS AND SYSTEMS OF NETWORK VOLTAGE REGULATING TRANSFORMERS - Methods and systems of network voltage regulating transformers are provided. A network voltage regulating transformer (NVRT) may provide voltage transformation, isolation, and regulation. A NVRT may further provide power factor corrections. Multiple NVRTs may operate autonomously and collectively thereby achieving an edge of network voltage control when installed to a power system. A NVRT comprises a transformer, a VAR source, and a control module. The input current (i.e., the current through the primary side of the transformer), the output current (i.e., the current through the secondary side of the transformer), and/or the output voltage (i.e., the voltage across the secondary side of the transformer) may be monitored. | 04-17-2014 |
20140117948 | VOLTAGE CONTROL APPARATUS, CONTROL METHOD THEREFOR, AND VOLTAGE CONTROL PROGRAM THEREFOR - Provided are a control-amount separating section that separates, when it is determined that an interconnection-point voltage (Vr) at an interconnection point where a wind turbine is connected to a utility grid deviates from a target value, a target control amount for reactive power for matching the interconnection-point voltage (Vr) with the target value into a first control amount serving as a control amount for reactive power that is caused by a fluctuation in active power at the interconnection point and a second control amount serving as a control amount for reactive power that is caused by a change in a power flow in the utility grid; a wind-turbine control device that controls the switching device on the basis of the first control amount; and a capacitor-bank control device that controls the capacitor bank on the basis of the second control amount. | 05-01-2014 |
20140266083 | Energy-Saving Device with a Voltage-Regulating Function - An energy-saving device is electrically connected between an output terminal of an electric power and an input terminal of a load and includes a current dividing unit connected with the load in parallel, and a voltage dividing unit connected with the load serially. The current dividing unit has an input terminal electrically coupled to an output terminal of the load and an output terminal electrically coupled to the input terminal of the load. The voltage dividing unit has an input terminal electrically coupled to the output terminal of the electric power and an output terminal electrically coupled to the input terminal of the load. Thus, the voltage dividing unit drops the voltage of the load applied by the electric power, and the current dividing unit increases the current flowing into the load, so that the energy-saving device achieves an energy-saving purpose. | 09-18-2014 |
20140327411 | POWER FACTOR CORRECTION ALGORITHM FOR ARBITRARY INPUT WAVEFORM - The present disclosure provides techniques for a power factor correction system having an arbitrary input waveform. The present disclosure provides two example methods of digital power factor correction that allow for a high power factor on an arbitrary input waveform. The two example methods are applicable to both constant-current inputs and constant-voltage inputs. One example method samples the arbitrary input waveform to produce a reference table used to synchronize the input voltage with the input current in a constant current system, and to synchronize the input current to the input voltage in a constant voltage system. A second example method uses instantaneous input values as a reference in performing power factor correction. | 11-06-2014 |
20150028821 | CONTROL CIRCUIT FOR REDUCING TOUCH CURRENT OF A POWER CONVERTER AND OPERATION METHOD THEREOF - A control circuit for reducing touch current of a power converter includes an auxiliary pin, a zero-crossing signal generator, a frequency limiting signal generator, and a gate signal generator. The auxiliary pin is used for receiving a voltage generated by an auxiliary winding of the power converter. The zero-crossing signal generator is used for generating a zero-crossing signal according to the voltage generated by the auxiliary winding and a first reference voltage. The frequency limiting signal generator is used for generating a frequency limiting signal according to a gate control signal, a burst mode signal, and the voltage generated by the auxiliary winding. The frequency limiting signal is used for limiting the gate control signal to a predetermined frequency. The gate signal generator is used for generating the gate control signal to a power switch of the power converter according to the frequency limiting signal and the zero-crossing signal. | 01-29-2015 |
20150048807 | Power Factor Correction Circuit and Method - A power factor correction (PFC) circuit includes a first inductor, which is operably supplied with an input voltage and an input current. The input voltage is a rectified AC line voltage. A semiconductor switch has a load current path coupled in series with the first inductor. An output terminal is coupled to the inductor and operably providing an output voltage and an output current. A controller circuit controls the cyclic switching operation of the semiconductor switch. The controller circuit is configured to monitor a feedback signal representing the voltage drop across the load current path of the semiconductor switch, to detect at least one local minimum in the feedback signal while the semiconductor switch is off, and to switch on the semiconductor switch in response to detecting the N-th local minimum in the feedback signal. | 02-19-2015 |
20150061608 | POWER FACTOR CORRECTOR - A power factor corrector correcting the power factor of an alternating current (AC) voltage is disclosed. A power factor correcting unit corrects the power factor of the AC voltage. A smoothing unit smoothes a power factor corrected voltage and includes a film condenser and a plurality of electrolytic condensers. A rectified voltage is applied to one end of an inductor. One end of a switch is connected to the other end of the inductor, and the other end of the switch is earthed. One end of a diode is connected to one end of the switch. One end of a film condenser is connected to the other end of the diode, and the other end of the film condenser is earthed. An electrolytic condenser is parallel-connected to the film condenser. | 03-05-2015 |
20150102786 | PFC CONTROL CIRCUIT, ACTIVE PFC CIRCUIT AND PFC CONTROL METHOD - The present invention relates to a PFC control circuit, an active PFC circuit, and a PFC control method. According to an embodiment of the present invention, a PFC control circuit including: an inductor current sensing unit for sensing an inductor current of a PFC circuit; an output voltage feedback unit for outputting a feedback output signal; a sensing and feedback signal application unit for outputting a sensing voltage signal during switching duty on of the PFC circuit and adding the feedback output signal to the sensing voltage signal to output the added signal during switching duty off of the PFC circuit; and a PFC control unit for generating a comparison signal and generating a duty control signal from the comparison signal and a first reference signal to make variations due to an internal offset be removed or reduced is provided. | 04-16-2015 |
20150311718 | OPTIMIZING VOLTAGE AND VAR ON THE ELECTRIC GRID USING DISTRIBUTED VAR SOURCES - A plurality of edge of network grid volt ampere reactive (VAR) sources are provided in a power system in order to effectuate control at a customer level, which in turn effectuates control at a feeder level, which in turn effectuates control of an entire power system or wide area electric grid network. By optimally selecting voltage setpoints and applying such voltage setpoints to the plurality of edge of network grid VAR sources, the power system can be configured to self-balance, power factor compensation can be determined without the need for measuring load power factor. Moreover, traditionally volatile voltages at the feeder can be flattened, and VAR control can be realized. | 10-29-2015 |
20150323949 | METHOD AND APPARATUS TO INCREASE EFFICIENCY IN A POWER FACTOR CORRECTION CIRCUIT - A power factor correction (PFC) controller includes a driver circuit coupled to vary the switching frequency of the power switch of the PFC converter in response to an input current of a PFC converter and an input voltage of the PFC converter, and to output a third signal to switch the power switch of the PFC converter to control the input current to substantially follow the input voltage. A frequency adjust circuit is coupled to receive an error voltage signal representative of an output of the PFC converter. The frequency adjust circuit is further coupled to output an adjusted error signal to adjust the end of the off time of the power switch of the PFC converter in response to the error voltage signal. | 11-12-2015 |
20160028360 | Hybrid Thrryristor Controlled Series Capacitor and Passive Damping Filter for Series Capacitors - Provided is a series capacitor for controlling a flow of power on a transmission line, and includes a filter circuit, and a thyristor-controlled circuit, wherein an interconnection and operation of the filter circuit and the thyristor-controlled circuit are performed based on a coordination of control thereof, to connect to a series capacitor bank on a transmission line. | 01-28-2016 |
20160043635 | Algorithm for Passive Power Factor Compensation Method with Differential Capacitor Change and Reduced Line Transient Noise - A computer-implementable control algorithm that measures: 1) the reactive power; 2) the power factor; 3) the voltage; and 4) the line frequency. The algorithm calculates the differential compensation capacitance required that is either positive (capacitance to be added), or negative (capacitance to be removed). The new compensation capacitance is calculated from the sum or difference of the differential compensation capacitance and the current compensation capacitance. The algorithm compares the capacitor switching bit pattern for the current compensation capacitance and the capacitor switching bit pattern for the new compensation capacitance, and selects a capacitor switching bit map accordingly. The capacitor switch combination for the new compensation capacitance is switched in incrementally according to the capacitor switching bit map. To reach the selected capacitor switch combination, only one switch is switched at a time to minimize the line transient noise. This part of the algorithm continues to run until the PF is corrected, with the capacitor switches being switched on/off each delayed by a millisecond interval to minimize line transient noise. | 02-11-2016 |
20170235323 | METHODS AND SYSTEMS OF NETWORK VOLTAGE REGULATING TRANSFORMERS | 08-17-2017 |