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7622826 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...
7508689 Inverter and a drive system using the inverter  
A inverter has a switching device for switching DC to change it to AC, and a bipolar type rechargeable battery connected to the switching device in parallel or in series for smoothing the current...
7436661 Two-compartment AC adaptor  
An external AC power adaptor having an additional compartment for cooling. The adaptor has a housing that defines a first compartment having power circuitry for converting an AC input to a DC...
7382303 Non-perturbing power supply margin controller  
A power supply margin controller may alter the voltage of a control signal used to control the output voltage of a power supply. The controller may include a digital-to-analog converter having an...
7365525 Protection for switched step up/step down regulators  
A four switch voltage converter is regulated for buck mode and boost mode under constant frequency valley-peak current mode control. Protection circuits are responsive to output voltage and...
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...
7208919 Method and apparatus for digitally regulating an output voltage using noise-shaped component selection  
Provided is a digitally-controlled linear regulator having noise-shaped component selection. The digitally-controlled linear regulator has a regulated-voltage sensor, a comparator module, a...
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...
7002321 Automatic power factor correction using power measurement chip  
An automatic power factor correction system, for an electrical power installation drawing varying levels of reactive power, measures an electrical parameter of the power drawn by a load of a power...
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...
6930459 Method for reducing the influence of a DC current component in the load current of an asynchronous motor  
A method with which the load current and thus the load moment of an asynchronous motor that is controlled via a phase-controlled two-phase thyristor power controller, can be easily influenced so as...
6917188 Power converter circuitry and method  
A switching power supply controller coupled to a first switching power supply circuit and a second switching power supply circuit, the controller sensing voltages provided to the first switching...
6868293 System and method for energy usage curtailment  
A system and method are disclosed for performing energy usage management within a network. The system may include an energy management system, such as a thermostat device, that may be associated...
6856120 Regulator circuit  
A regulator circuit capable of reducing an increase in an output voltage during a sudden drop in a load current without increasing the power consumption during a steady state. When a current in...
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...
6700358 Automatic power factor correction system  
An automatic power factor correction system, for an electrical power installation drawing varying levels of reactive power, measures an electrical parameter of the power drawn by a load of a power...
6661207 Apparatus and method for protecting synchronous generators against off-nominal frequency deviation and alternating forces excitation  
An apparatus and method for protecting synchronous generators against off-nominal frequency deviation and alternating forces excitation is provided. Particular application can be found with...
6559622 System for preventing overreach of protection for series compensated power lines  
The system includes an enable signal applied to an output AND element. A comparator compares the voltage ratio of selected measured and calculated phase-to-phase or single phase voltages against a...
6519537 Apparatus providing on-line indication of frequency of an AC electric power system  
Apparatus for determining the frequency of an ac power signal, includes sensing circuitry to sense the ac signal. In a digital implementation of the invention, a double average of the samples is...
6297940 Protection system for devices in an electrical distribution network  
A computer-implemented protection system is used in a multi-phase electrical distribution network. The system includes a sensor operable to measure an impedance of a device connected to a phase of...
6285169 Sag generator with switch-mode impedance  
A voltage sag generator for alternating current power systems intentionally creates power quality disturbances. The sag generator has a switch-mode impedance between its input and its output....
6191563 Energy saving power control system  
Apparatus and methods for AC power regulation primarily intended for inductive loads (e.g., fluorescent lights, motors, etc.) which provide substantial reduction in power consumption while also...
6147475 Prediction of harmonic distortion and application of power-factor correction in AC power systems  
In a method for predicting harmonic-distortion values for the application of a desired step change of capacitance to an AC system, an initial step change is applied and, from this change, a value...
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...
6057651 Lighting apparatus  
A lighting apparatus includes a full-wave rectifier circuit for rectifying an AC voltage from a commercial power source, a smoothing condenser connected is series with an inductor and a diode...
6020659 Ramping electronic switch system  
The present invention relates to an electronic switch system for controlling AC power to a load. The switch has ON, OFF and RAMP down modes that can be selected by means of momentary touch...
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...
5801459 Control equipment for a series capacitor connected into an electric power line  
Control equipment (CE) for a series capacitor (1) connected into an electric power line (2) has a semiconductor valve (3), which is controllable in both directions, for connection in parallel with...
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...
5719757 Three-phase rectifier circuit having capacitors which are switched into the circuit dependent on the rectifier output voltage  
A three-phase rectifier circuit for a capacitive load wherein only small current harmonics occur has, at the rectifier input, an inductance and a capacitor arrangement that compensates the reactive...
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...
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...
5663633 Touch control fan and method  
A control circuit for an electrical appliance having an inductive load includes a signal conditioning element, a control element, a power conditioning element, a power adjustment element, and a...
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...
5646512 Multifunction adaptive controls for tapswitches and capacitors  
A power system relay combining the functions of tapchanger control, capacitor control, substation data monitoring and communications.
5644214 Power factor correction circuit  
A continuous current type power factor correction circuit in a power device having rectifying means for rectifying an alternating current, a booster converter having an inductor, a diode and a...
5617447 Method of stabilizing a power supply network against reactive load fluctuations, and a reactive power compensation device  
When operating, DC arc furnaces generate undesired reactive load fluctuations which are compensated without special compensation reactance by a reactive power controller. As compensation reactance,...
5583423 Energy saving power control method  
Apparatus and methods for AC power regulation primarily intended for inductive loads (e.g., fluorescent lights, motors, etc.) which provides substantial reduction in power consumption while also...
5574356 Active neutral current compensator  
An active power conditioner for mitigating zero-sequence currents in electrical distribution by items wherein a multi-phase, neutral-forming structure employs a controllable voltage source, which...
5568042 Monitoring and control of a filter in a power network  
In a method for monitoring and/or control of a plant component (4A, 4B, 4C, 4D) connected to an electric power network (N1, N2), for example a tunable filter for harmonic filtering or a capacitor...
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...
5535087 Circuit for reducing effects of transient events on electronic equipment  
A circuit for reducing the effects of unpredictable changes in power supply and variations in loading on sensitive equipment, e.g. CT scanning system, to reduce inaccurate readings and protect...
5532575 Multilevel converter with capacitor voltage balancing  
A multilevel convertor having a set of series-connected capacitors and a set of associated series-connected switching elements employs a main control loop which controls some aspect of an AC...
5465040 Three phase power factor correction device and method  
In one form of the invention, a method for improving power factor in a multiple phase power distribution system coupled to a load is disclosed, comprising the steps of (a) sensing an actual voltage...
5402058 Method and apparatus for controlling discharge of a thyristor-switched capacitor  
A static VAR compensator (11) is connected across a power transmission line (10) and includes a capacitor (12) connected to transmission line (10). The static VAR compensator (11) includes a...
5402057 System and method for coordinating shunt reactance switching  
A system and method for coordinating shunt reactance switching in a system with a transformer having a primary voltage and a secondary voltage for supplying low voltage power to a load. Voltage and...
5374853 Transient damping thyristor controlled series capacitor system  
A thyristor controlled series capacitor (TCSC) system, including a method and apparatus, uses phase controlled firing based on monitored capacitor voltage and line current. For vernier operation,...
5367197 Series capacitor equipment  
Series capacitor equipment for connection into an electric power line (A) has a capacitor bank (C) and a controllable inductor connection (L, T1, T2) connected in parallel therewith and comprising...
5349283 Automatic voltage control circuit by using reactive power  
An automatic voltage control circuit by using reactive power is disclosed. The circuit comprises a proportional integrator, a triangular wave generator, a comparing circuit having first and second...
5227713 Vernier control system for subsynchronous resonance mitigation  
A subsynchronous resonance mitigation system, including a method and apparatus, for damping undesirable subsynchronous resonance oscillations in a generator, which, if left unchecked, may damage...
Matches 1 - 50 out of 100 1 2 >