Matches 1 - 50 out of 159 1 2 3 4 >
Match Document Document Title
7514907 Device, system, and method for providing a low-voltage fault ride-through for a wind generator farm  
A device, a system, and a method for preventing power-producing wind turbine generators from tripping due to the detection of a low-voltage condition on a power grid are disclosed. The disclosed...
7382112 Methods and devices for input waveform control in switching power supplies  
The invention recognizes that filter size can be reduced substantially as power factor is permitted to deviate below unity in systematic ways. Preferred methods of the invention provide specific,...
7368891 Charge control method of capacitor in thyristor converter  
Charging time of a capacitor is shortened while avoiding erroneous firing due to distortion of a power supply voltage and sustaining an inrush current at a constant level. In the charge control...
7353122 Power converters with limited operation to conserve power and with adjustments that overcome ringing  
To conserve power when regulating the output voltage (Vo) of a power converter, no adjustment is made to the converter's pulse width modulation times (Tp, Ts) even if the output voltage is off...
7265521 Reactive power compensation to minimize step voltage changes and transients  
The invention features a system and approach for minimizing the step voltage change as seen by the utility customer as well minimizing transients imposed on the fundamental waveform of a normal...
7183752 Connection method for a static VAR compensator  
A static VAR compensator has several parallel compensation components (K 1 –K 3 ). To connect the static VAR compensator to an operating voltage (U) the compensation components (K 1 –K 3 ) are...
6954046 Method and apparatus to control input to AC induction motors  
One embodiment of the present invention is a method to control input to an alternating current (AC) induction motor from a power supply that includes steps of: (a) determining a measure of reactive...
6867570 Circuit arrangement for the static generation of a variable electric output  
The novel circuit arrangement is used for the static generation of a variable electric output, as is common in static reactive-power compensation systems. According to the invention, a voltage is...
6847183 Electronic power supply for a synchronous motor with permanent-magnet rotor having two pairs of poles  
A low noise synchronous motor including a permanent-magnet rotor and a stator with at least two pairs of stator poles and corresponding winding further includes an electronic power supply...
6674267 Method and a device for compensation of the consumption of reactive power by an industrial load  
An industrial load, preferably an electric arc furnace or a plant for rolling of metallic materials, is supplied from a three-phase electric ac network. A device for compensation of the reactive...
6621253 Amplifier having a variable power factor  
A multiple power factor audio amplifier with a power draw up to a maximum amplifier power draw flowing through at least two power flow circuits with at least one circuit including a power factor...
6600294 Switched reactance phase shifters  
A phase shifter is disclosed in which parasitic elements in a microelectromechanical system (MEMS) switch are designed and utilized to provide a predetermined phase shift. In one embodiment, a...
6552598 Semiconductor high voltage electrical energy transmission switching system and method  
A method for controlling fault interruption in a high voltage electrical energy transmission system semiconductor high voltage electrical energy transmission switching system which includes a...
6331765 Series compensator  
A series compensator, connected in series to an AC transmission line, for compensating for an electric amount, such as a voltage, current, phase or impedance, of the AC transmission line, comprises...
6255806 Supply device for power supply to an electronic unit in a semiconductor valve in a shunt-connected thyristor-switched capacitor  
A supply device (FD1, FD2) for power supply to an electronic unit (EU1, EU2) for a controllable semiconductor element (T1, T2) in a semiconductor valve in a shunt-connected thyristor-switched...
6225791 Controller for performing a decoupling control of a transformerless reactive series compensator  
A controller for generating a modulation signal m applied to a transformerless reactive series compensator connected serially in a power transmission line. A modulation signal generator generates a...
6121758 Adaptive synchronous capacitor switch controller  
A method and apparatus are provided directed to a synchronous and adaptive capacitor switch controller for minimizing transients in the power factor correction of an electric power distribution...
6114841 Method and device for compensation of reactive power  
A device for compensation of the reactive power consumption of an industrial load, preferably an electric arc furnace or a plant for rolling of metallic materials, supplied from a three-phase (a,...
6075349 Compensation device and power transmission system using a compensation device  
The invention relates to a compensator device connected in series to power transmission lines and including at least one compensator unit with a transformerless reactive series compensator. The...
6058134 Method for measuring the electric quantities of an AC electric-arc furnace  
This invention relates to a method for measuring the electrode-related electric quantities of an AC electric-arc furnace. The method is based on observing the mutual correlation between electrode...
6023153 Audio amplifier having power factor correction  
An audio amplifier for receiving input current and sinusoidal line voltage from an AC source, and delivering audio output power to a load includes: a power factor correction circuit for receiving...
5969509 Method and a device for control of a capacitor device for a shunt-connected compensator unit  
A device for control of a capacitor device for a shunt-connected static compensator unit (COM1, COM2, COM3) for compensation of reactive power in an electric power network (NW). The capacitor...
5963021 Delayed contact closing apparatus and method for capacitors  
A transient reducing capacitor switching device that switches grounded capacitors into a multi-phase power line, wherein each phase of the line carries an AC voltage signal that cycles its...
5942880 Compensation control device for a power system  
A compensation control device for a power system includes a switched capacitor connected in series with a transmission line, a voltage applying control connected in series with the transmission...
5909105 Control of power networks  
In an apparatus for control of controller equipment for damping power oscillations in a power line, the controller equipment is serially connected between a first connection point and a second...
5907234 Thyristor-switched capacitor bank  
A thyristor-controlled capacitor bank includes a thyristor switch and a capacitor bank. The capacitor bank is split into at least two series-connected capacitor groups. A series circuit including a...
5905367 Power inverter apparatus using a transformer with its primary winding connected the source end and a secondary winding connected to the load end of an AC power line to insert series compensation  
Series voltage compensation is provided in an ac power line by connecting the inverter unit of a dynamic voltage restorer (DVR) in series with the primary winding of a load transformer, which may...
5900723 Voltage based VAR compensation system  
A VAR generator compensation system wherein the voltage of the capacitor or reactor bank is changed as a means of adjusting the phase angle is taught. Briefly stated a reactive bank such as a...
5825162 Electric power flow controller  
An electric power flow controller for controlling an electric power flow of a power system includes a semiconductor switch for controlling a series reactance of the power system. The electric power...
5818707 Simplified active power factor correction controller IC  
Disclosed is an active power factor correction integrated circuit for a boost converter, comprising a bias voltage generator coupled to an external power source through a first pin, for generating...
5818208 Flicker controllers using voltage source converters  
Voltage flicker is a power quality problem in power distribution circuits which is caused by the operation of fluctuating loads such as AC and DC electric arc furnaces, spot welders, starting of...
5818126 Power transfer controller  
A method and apparatus for controlling power transferred and regulating voltage in a multi-phase transmission line includes generating a first plurality of voltages, a second plurality of voltages...
5809054 Method for stabilizing an AC system against reactive-load fluctuations, and a power-factor correction device  
In operation, DC arc furnaces generate undesired reactive load fluctuations which are compensated for by a power controller without special compensation reactance. In order to permit a melting...
5798634 Load management and control apparatus  
A load management and control apparatus comprising a control unit in which system voltage and a power flow state are measured to make an arithmetic decision by using the resultant variations in...
5796631 Method and apparatus for monitoring and characterizing power quality, faults and other phenomena in network power systems  
A method and apparatus for receiving, monitoring and characterizing network power information in real time through the use of a specialized display system. A processor receives three phase current...
5736838 High speed power factor controller  
A microprocessor (42) is coupled to sense the current and voltage in an AC line (11) at a high sampling rate and to determine the power factor. In one embodiment the primary (83) of a transformer...
5710492 Apparatus for monitoring and stabilizing power swing in a power system by utilizing a power electronics technique  
In a power system wherein a plurality of power plants, load systems and power transmission components are connected to each other for increasing the power transmission capacity of the power system,...
5677832 Active filter  
An active filter for compensation of polluting harmonics on an electricity distribution network comprising a source of energy (19, 20), a bridge converter (21) connected between the energy source...
5672957 Method and device for reducing voltage imbalances in a three-phase network by means of a static compensator  
The invention relates to a method and a device for reducing imbalances (ΔV 12 , ΔV 23 , ΔV 31 ) in a three-phase network (42) by means of a static compensator. According to the invention, a...
5672956 Static reactive power compensating equipment  
A static reactive power compensating equipment includes a circuit for preventing harmonic currents generated by adjusting lag compensation current from phase control from flowing out of the...
5670864 Adaptive automatic power capacitor for controlling controller a capacitor bank of a power distribution system  
A power capacitor controller that adaptively and/or automatically determines a variety of operational parameters, including adaptively and automatically establishing the line phase angle correction...
5656924 System and method for providing harmonic currents to a harmonic generating load connected to a power system  
A system and method for providing harmonic currents to a harmonic generating load connected to a multiphase alternating current power system includes a zig-zag transformer and a current generator....
5654625 Switching circuit for a reactive power compensation device having synchronized on and off switching  
Using a switching circuit (2) for a reactive power compensation device (1), he compensation capacitors of the reactive power compensation device (1) can be switched on with voltage measuring...
5631545 Apparatus and method for regulating a power line using frequency domain self-synchronization control  
A frequency domain self-synchronization controller for solid state switches is disclosed. The controller analyzes a measured power signal in the frequency domain to identify a frequency domain...
5627454 Method for stabilizing a power supply network against reactive load fluctuations, and a power factor compensation device  
During operation, DC arc furnaces (8) produce undesired reactive load fluctuations which are compensated by means of a power factor compensator (31). An AC power controller (28) of the power factor...
5621305 Overload management system  
An overload management system is provided, including a method and an apparatus, for controlling the operation of electrical equipment in a short-term overload region above the equipment's...
5612609 Continuous conduction mode switching power supply with improved power factor correction  
A power factor correction circuit in which an inductor current is detected separately as a charging current indication signal and a discharging current indication signal by using a current sense...
5548203 Capacitor polarity-based var correction controller for resonant line conditions and large amplitude line harmonics  
The invention is a static VAR compensator (SVC) which provides optimized power factor correction in the presence of resonant line conditions and large amplitude harmonics. A gate drive signal is...
5541498 Distribution circuit var management system using adaptive capacitor controls  
This invention provides various methods and techniques for adaptive control of pole-top capacitors to compensate for inductive customer loads along distribution lines together with control of Var...
5489838 Method and apparatus for generating a synchronizing signal for a controlled series compensator  
A method and apparatus is described for generating a synchronizing signal for a firing-circuit subassembly to trigger a power converter valve of a controlled series compensator. According to the...
Matches 1 - 50 out of 159 1 2 3 4 >