Abstract: The present invention addresses the problem of avoiding that wind turbine voltage levels within a wind power plant do not exceed predetermined overvoltage and/or undervoltage protection levels. In particular, the present invention relates to shifting of an output voltage level of a wind power plant in order to protect an internal power plant grid against overvoltages.

Abstract: A power control apparatus includes: a first obtainment unit which obtains a power flow value at a power flow measuring point and a voltage value at a voltage measuring point provided; a power flow control unit which calculates a first power change value, to cause the power flow value to approach a predetermined target value; a voltage control unit calculates a voltage value at the voltage measuring point when the first power has been changed by the first power change value, and sets a second power change value, based on whether or not the voltage value falls within a predetermined voltage range; and a notification unit which notifies the power adjustment apparatus of a command value for causing the power adjustment apparatus to input or output the first power changed by the first power change value and the second power changed by the second power change value.

Abstract: A transmission system and a method for transmitting electrical power which has been produced by at least one off-shore wind turbine to a utility grid being located on-shore is provided. The transmission system has (a) an off-shore transformer, which is connectable to the at least one wind turbine and which is configured for changing a first AC voltage level provided by the at least one wind turbine to a second AC voltage level, (b) a subsea AC transmission cable having an off-shore input end and an on-shore output end, wherein the input end is connected to the off-shore transformer, and (c) a compensation unit for compensating at least partially a reactive power being produced within the subsea AC transmission cable, wherein the compensation unit is electrically coupled to the subsea AC transmission cable at a node being located in between the off-shore input end and the on-shore output end.

Abstract: A dynamic high-energy switch used for correcting load imbalance through connecting and disconnecting capacitance in a power feed circuit.

Abstract: A system, method and apparatus for automatically adapting power grid usage by controlling internal and/or external power-related assets of one or more users in response to power regulation and/or frequency regulation functions in a manner beneficial to both the power grid itself and the users of the power grid.

Abstract: A modulation method is provided. The modulation method includes the steps of receiving multiple sinusoidal signals, obtaining the maximum value of the sinusoidal signals, obtaining the median value of the sinusoidal signals, and obtaining the minimum value of the sinusoidal signals within a period to generate a difference between the maximum value and the minimum value, generating a difference according to an upper limit and a lower limit of a predetermined comparison value, and comparing the two differences to generate an optimized modulation signal.

Abstract: According to an embodiment, a voltage fluctuation suppressing apparatus is provided with a power storage device connected to an electric power system, a basic control unit to control an output of the power storage device, a voltage detector to measure a voltage of a connection point to the electric power system, and an output control unit to divide a control amount to be outputted to the basic control unit into a reactive power command value and an active power command value and to output them. The output control unit is provided with a reactive power upper limit value calculation unit, a reactive power calculation/output unit, and an active power calculation/output unit.

Abstract: A voltage control apparatus includes: a voltage value obtainment unit configured to obtain voltage values at the one or more voltage measuring points; an impedance obtainment unit configured to obtain a system impedance from a distribution substation to each of power adjustment apparatuses; a control variable calculating unit configured to calculate a control variable including at least one of (i) a value corresponding to an allowable upper limit of a voltage value at the first voltage measuring point and (ii) a value corresponding to an allowable lower limit of the voltage value at the first voltage measuring point, based on the voltage values at the one or more voltage measuring points and the system impedances; and a notification unit configured to notify the power adjustment apparatuses of the calculated control variable.

Abstract: An apparatus is capable of improving the power factor of a power supply powered by a high power line and a ground power line. The apparatus comprises a line voltage detector and an ON time controller. The line voltage detector provides a scaled voltage to represent a line voltage of the high power line. The ON time controller has a valley voltage detector, which provides, in response to the scaled voltage, a valley representative representing a valley voltage of the line voltage. The ON time controller controls an ON time of a power switch in the power supply in response to the valley representative.

Abstract: An apparatus, a method, and a computer program product are provided. The apparatus determines an input voltage and an input current of a power system driving a low power factor load, the input voltage varying based on a power cycle, determines at least a first portion of the power cycle at which the input current exceeds a threshold, and couples at least one substantially resistive load to the low power factor load during at least a second portion of the power cycle different from the at least a first portion of the power cycle.

Abstract: In a reactive power compensation device, a control unit controls a magnitude of reactive power to be output by a reactive power output unit, based on a detected system voltage and one or more control parameters in a first operation mode. In a second operation mode, the control unit changes the magnitude of the reactive power to be output by the reactive power output unit to a power system in an output change period, calculates system impedances of the power system at a plurality of detection time points within the output change period, based on change amounts of the system voltage detected at the plurality of detection time points and corresponding change amounts of the reactive power, and, when a variation in the calculated system impedances is within an acceptable range, adjusts the one or more control parameters, based on the calculated system impedances.

Abstract: An Engineer's View (EV) wireless video system for powered and unpowered model railroad engines is disclosed. The invention uses commercially available wireless spy cameras, powered by a custom power supply circuit which is compatible with either DC or DCC track systems. The present invention is compatible with all commercial model railroad gauge diesel engines including HO and N Gauge or may be factory installed. The EV system demonstrates a remarkably stable and realistic image of a model railroad layout. Moreover, the present invention may also provide a stable source of power to the engine where stalling could occur at points of track defects.

Abstract: In one embodiment, a power factor correction (PFC) circuit can include: (i) a rectifier bridge and a PFC converter coupled to an input capacitor; (ii) a harmonic wave compensation circuit configured to shift a phase of a DC input voltage provided from the rectifier bridge, where the harmonic wave compensation circuit comprises a phase of about ?45° when a corner frequency is about 50 Hz; and (iii) a PFC control circuit configured to control the PFC converter, where the PFC control circuit comprises a first sampling voltage, and the harmonic wave compensation circuit is configured to control a phase of the first sampling voltage to lag a phase of the DC input voltage by about 45°.

Abstract: A power electronic converter for use in high voltage direct current power transmission and reactive power compensation which includes at least one converter limb including first and second DC terminals for connection in use to a DC network. The or each converter limb includes at least one first converter block and at least one second converter block connected between the first and second DC terminals. The or each first converter block includes a plurality of line-commutated thyristors and at least one first AC terminal for connection in use to an AC network. The or each second converter block includes at least one auxiliary converter including a plurality of self-commutated switching elements. The self-commutated switching elements are controllable in use to inject a voltage to modify a DC voltage presented to the DC side of the converter limb and/or modify an AC voltage and an AC current on the AC side of the power electronic converter.

Abstract: Reducing current harmonics at light loads is disclosed. In an example, a method includes increasing output voltage of a boost converter to reach a higher potential in a low power mode. After reaching the higher potential, the method includes dropping a set point for the output voltage.

Abstract: The present invention relates to a control method for supporting active power factor correction (APFC) loads, comprising: providing square wave width of an output voltage waveform to be a comparatively large value to improve effective value of the output voltage, in order to meet the requirements for active power factor correction (APFC) loads; and gradually decreasing square wave width of the output voltage waveform from the comparatively large value to a comparatively small value to gradually decrease effective value of the output voltage to a desirable stable voltage effective value.

Abstract: A controller for use in a power converter includes a load sensing circuit coupled to output an error signal in response to a feedback signal representative of an output of the power converter. The error signal is representative of a load coupled to an output of the power converter. A burst mode control circuit is coupled to output a burst mode control signal in response to the error signal. An offset current generator circuit is coupled to output an offset current in response to the error signal. A drive circuit is coupled to control switching of a power switch to control a transfer of energy from an input of the power converter to the output of the power converter in response to the error signal, the burst mode control signal, the offset current, and a current sense signal representative of a current through the power switch.

Abstract: An electrical power generation system, such as a solar power inverter, can provide dynamic real-time power compensation, so as to mitigate the effects of voltage sags and swells (e.g., on a utility grid) and thereby provide voltage support functionality to a local grid. The electrical power generation system can do so by receiving first synchrophasor measurements that are taken at a point on the utility grid and transmitted to the electrical power generation system and by taking second synchrophasor measurements. The first and second synchrophasors indicate voltage magnitude and frequency of the alternating current (AC) at their respective measurement points. The electrical power generation system can compare the first synchrophasors with the second synchrophasors and based upon the comparison, vary the power factor of the power the electrical power generation system generates (e.g., by either supplying or absorbing reactive power).

Abstract: A method for controlling electric power supply, the method comprising: (a) controllably down converting by a step-down power converter entry voltage from a power source and preventing up-conversion by a step-up power converter, substantially when the entry voltage is larger than a measured exit voltage and is in compliance with a first criterion that is based on the entry voltage and on the measured exit voltage; wherein the measured exit voltage is measured at an exit of both step-up power converter and the step-down power converter; and (b) controllably up converting by the step-up power converter the entry voltage and preventing down-conversion by the step-down power converter, substantially when the entry voltage is lower than the measured exit voltage and is in compliance with a second criterion that is based on the entry voltage and on the measured exit voltage.

Abstract: Electrical power is fed from a wind energy installation into an AC voltage system via an energy transmission path, which is delimited by an installation-side transformer and a system-side transformer. A power factor correction device is connected, at a common node between the energy transmission path and the AC voltage system using a closed-loop control device, which controls the wind energy installation and which receives a variable which is proportional to the reactive power on the energy transmission path and a further measured variable. A measurement signal produced at the output of the power factor correction device is used as further measured variable. The closed-loop controller has such a control characteristic that the voltage on the low-voltage side of the system-side transformer increases, depending on the reactive power on the energy transmission path, from the inductive range to the capacitive range.

Abstract: A power source system including power-factor modifying circuits to modify a power factor of supplied electric power, a time difference circuit to output start signals for instructing the power-factor modifying circuits to start an operation to the power-factor modifying circuits at specified time intervals, and a control circuit to supply the electric power to the power-factor modifying circuit to start the power-factor modifying circuit when the power-factor modifying circuit acquires the start signal output from the time difference circuit.

Abstract: The present disclosure provides techniques for power factor correction on a constant current system. In an example embodiment, the present disclosure provides a power factor correction circuit which receives a constant current power input. The power factor correction circuit provides an input voltage tuned to match the phase of the input current. The input voltage is tuned via charging and draining an input capacitor by a switching device. The switching device is driven on a duty cycle synchronously associated with the input current waveform.

Abstract: Aspects relate to utilizing power factor correction to compensate for a leading power factor produced mainly due to electromagnetic interference (EMI) capacitors in front of a power factor correction stage. Provided is a power supply that includes a power factor correction circuit that includes a second harmonic generator component. The harmonic generator component includes a filter component and an integrator component. The filter component is configured to receive a rectified voltage and a power factor correction current and block a direct current component. The integrator component is configured to receive an alternating current component from the filter component and produce a harmonic that causes an angle of the power factor correction current to change from a leading power factor to a unity power factor or to a lagging power factor.

Abstract: A method for controlling the combustion in a gas turbine including measuring, with one or more probes situated adjacent to the combustion chamber of the turbine, the amplitude of the pressure oscillations inside the combustion chamber and the persistence time or cycle of the same oscillations, evaluating the behavior under fatigue conditions of the combustion chamber, by constructing the Wohler curve for a certain material which forms the combustion chamber for a predefined combustion frequency and for the amplitude and cycle values of the pressure oscillations measured, measuring the cumulative damage to the combustion chamber during functioning under fatigue conditions of the turbine using the Palmgren-Miner hypothesis and exerting protection actions of the turbine if the cumulative damage value measured is exceeded.

Abstract: An apparatus, system, and method are disclosed for providing power balancing for power supplies. A power module measures an amount of input power for each of a plurality of switching power supplies. A conversion module converts the measured amount of input power of each power supply to a digital power measurement signal. An averaging module determines an average amount of input power per power supply based on a summation of the digital power measurement signal of each power supply. A comparison module compares the digital power measurement signal of a power supply to the determined average amount of input power per power supply. An input power adjustment module adjusts the input power of the power supply to cause the amount of input power of the power supply to be substantially equal to the determined average amount of input power per power supply.

Abstract: A semiconductor device, comprising first and second field effect transistors arranged in a cascode configuration: wherein the first field effect transistor is a depletion mode transistor; and wherein the second field effect transistor comprises a first source to gate capacitance and a second additional source to gate capacitance connected in parallel to the first source to gate capacitance. A power factor correction (PFC) circuit comprising the semiconductor device. A power supply comprising the PFC circuit.

Abstract: A PFC circuit includes: a switching circuit having a power switch; an on time control circuit for controlling an on time period of the power switch; a first off time control circuit; a second off time control circuit; and a logic circuit selectively controls the power switch working under CCM or DCM; when working under CCM, the first off time control circuit controls an off time period of the power switch and when working under DCM, the second off time control circuit controls the off time period of the power switch.

Abstract: An embodiment relates to a method for adjusting a dead zone, wherein an amplitude of an oscillating signal is determined, and wherein the dead zone is adjusted based on the amplitude of the oscillating signal.

Abstract: A switching mode power converter includes a DSC with a digital PWM module configured for complementary operation mode during normal operation. The control algorithm of the DSC is configured such that during an initialization stage immediately following power up of the device relevant digital PWM modules used for interleaving operation are reconfigured to temporarily operate in an independent operation mode with the duty cycle associated with each channel set at zero. The reconfigured digital PWM modules remain set in the independent operation mode for a predefined period of time. Once the predefined time period is reached, the reconfigured digital PWM modules are again reconfigured back to the original complementary operation mode configuration and the control algorithm resumes normal operation of the DSC and digital PWM modules.

Abstract: A power supply circuit includes a pre-regulator configured to receive an input voltage and to generate an output voltage, and a switching current regulator coupled to an output of the pre-regulator and configured to regulate a level of current supplied to an output load. The switching current regulator is controlled by a switching signal having a duty cycle. The circuit further includes a controller that generates the switching signal. The controller monitors the duty cycle of the switching signal and controls a level of the output voltage generated by the pre-regulator by providing a control signal in response to the duty cycle of the switching signal.

Abstract: A method for cross-platform web-based native device feature access may include receiving a call from a web application to access a native device feature, with the call being redirected to a platform agnostic custom URL. The method may further include translating the custom URL into a native object call, and accessing the native device feature based on the native object call.

Abstract: Methods and systems for controlling a reactive power contribution to reactive power flowing in an electricity distribution network, so as to optimise this reactive power flow are described. A reactive power characteristic of electrical power flowing in the electricity distribution network is detected at a power device. The reactive power characteristic relates to a reactive power component of electricity flowing in the network. On the basis of the detected reactive power characteristic a reactive power contribution to the electricity distribution network is controlled so as to adjust a value of the detected reactive power characteristic. This enables individual power consumption and/or provision devices to react autonomously to local variations in the electricity distribution network, and to provide a reactive power contribution, to drive the detected reactive power characteristic towards a desired value.

Abstract: A dynamic high-energy switch used for correcting load imbalance through connecting and disconnecting capacitance in a power feed circuit.

Abstract: Aspects of the disclosure provide method and apparatus for detecting attributes of an input power supply. The method includes receiving a first signal generated based on a second signal that is predictive. The first signal includes a portion that substantially corresponds to the second signal. Further, the method includes detecting attributes of the portion of the first signal that substantially corresponds to the second signal, and determining attributes of the second signal based on the attributes of the portion of the first signal that substantially corresponds to the second signal.

Abstract: Techniques and systems are disclosed for managing computer resources available to multiple running instances of a media player program. The methods include monitoring consumption of computing resources of multiple running instances of a media player program to render respective media content in a graphical user interface of a computing device. The graphical user interface associated with an additional program configured to render additional content, different from the media content, to the graphical user interface. The additional program can be a browser. The methods further include instructing the multiple instances to reduce respective portions of the computing resources consumption upon determining that a requested increase in computer resources consumption of the media player program would cause the computer resources consumption of the media player program to exceed a first predetermined level.

Abstract: There are provided a power factor correction circuit capable of transferring extra power to a ground before performing switching for a power factor correction to thereby reduce a switching loss generated in switching for a power factor correction, and a power supply device and a motor driving device having the same. The power factor correction circuit includes: a main switch switching input power to adjust a phase difference between a current and a voltage of the input power; and an auxiliary switch switched on before the main switch is switched on, to thereby form a transmission path for extra power of the main switch.

Abstract: A method for regulating a power line voltage includes determining a slow voltage variation by filtering an actual voltage at terminals of the voltage regulation apparatus. A fast active power variation is determined by filtering a measured active power of the DG system; wherein a first frequency of the slow voltage variation is smaller than a second frequency of the fast active power variation. The voltage regulation apparatus settings are controlled based on the slow voltage variation and a reactive power output of the DG system is controlled based on fast active power variation.

Abstract: There are provided a power factor correction apparatus and a power supply apparatus, the power supply apparatus including a power supply unit switching input power to supply preset driving power to a load, and a control unit providing a switching control signal having a preset number of pulses for a predetermined time to the power supply unit to control power switching of the power supply unit, and when a voltage level of the driving power is equal to or higher than that of at least one intermediate voltage set between a preset normal operating voltage and a preset abnormal operating voltage, skipping a portion of the number of pulses of the switching control signal for the predetermined time.

Abstract: To prevent demagnetization of a permanent magnet synchronous rotating machine, a rotating machine control device according to the present invention is a rotating machine control device comprising: a power converter having a switch part on each of a positive side and a negative side for each phase; and short circuit detection unit for detecting a short circuit of the switch part, wherein a command to turn on positive-side switches and negative-side switches of a plurality of phases of the switch part is issued in the case where the short circuit detection unit detects the short circuit.

Abstract: A bridgeless power factor corrector with a single choke is electrically connected to an AC power source. The bridgeless power factor corrector includes a choke element, a first switch, a second switch, a first diode, a second diode, a capacitor, a first rectify diode, and a second rectify diode. The choke element is electrically connected between the first switch and the second switch. The first switch and the second switch are controlled to be turned on or turned off by a first control signal and a second control signal, respectively, to provide a power factor correction for the AC power source when the AC power source is in a positive half cycle or a negative half cycle. Furthermore, a method of operating the bridgeless power factor corrector is provided.

Abstract: A control integrated circuit for a power factor correction converter has a pin for detecting an alternating-current information and a direct-current information of an input signal. The control integrated circuit comprises a signal peak detector for detecting a peak value of the input signal to the pin to obtain the direct-current information of the input signal. Since the alternating-current information and the direct-current information of the input signal can be obtained through the same pin, the pin count of the control integrated circuit can be decreased.

Abstract: A linear transformer power supply is disclosed that extracts a high level of energy from a linear transformer during the full cycle of AC input voltage.

Abstract: In accordance with an embodiment, an electronic device includes a controller configured to be coupled to a first switch of a power factor corrector. The controller is configured to produce a variable switching frequency depending on a load current. For a first load current, the controller is configured to produce a first switching frequency, and for a second load current, the controller is configured to produce a second switching frequency.

Abstract: A method and an arrangement of tracking a selected (e.g., maximum) power point of a photovoltaic system is disclosed, in which method an operation point of the photovoltaic system is changed based on the change of operation point and a change of power generated by the photovoltaic system. The method can include repeatedly determining a current or voltage of the photovoltaic system, determining a power of the photovoltaic system, determining a change of power of the photovoltaic system with respect to a previous determined power, and changing the operation point of the photovoltaic system by changing a current or voltage reference of the system stepwise depending on the change of power and a direction of a previous change of the current or voltage reference.

Abstract: Methods and systems for mitigation of intermittent generation impact on electrical power system may be provided. A voltage of the power line may be monitored. A change in the voltage of the power line may be determined. A power output of an energy generation source connected to the power line may be altered based on the determined change in the voltage on the power line to compensate for the change in the voltage.

Abstract: An apparatus, a method, and a computer program product are provided. The apparatus determines an input voltage and an input current of a power system driving a low power factor load, the input voltage varying based on a power cycle, determines at least a first portion of the power cycle at which the input current exceeds a threshold, and couples at least one substantially resistive load to the low power factor load during at least a second portion of the power cycle different from the at least a first portion of the power cycle.

Abstract: The disclosed technology performs power factor correction involving rectifying and adjusting an input power supply signal with a PWM signal. The PWM signal is generated based on a closed feedback signal obtained from a load, as well as adjusted harmonic content retrieved from a sensed input power supply signal. The adjusted harmonic content is produced by extracting a fundamental signal and a plurality of harmonic signals from the sensed input power supply signal, modifying the plurality of harmonic signals by dividing by the fundamental signal, and combining the modified harmonic signals into a duty factor distortion signal. The duty factor distortion signal controls a duty factor of the PWM signal to provide a substantially square wave template. Furthermore, the power factor is increased by forcing the input power supply signal to follow the substantially square wave template.

Abstract: A controller for controlling power to a light source includes a first sensing pin, a second sensing pin, a third sensing pin, and a driving pin. The first sensing pin receives a first signal indicating an instant current flowing through an energy storage element. The second sensing pin receives a second signal indicating an average current flowing through the energy storage element. The third sensing pin receives a third signal indicating whether the instant current decreases to a predetermined current level. The driving pin provides a driving signal to a switch to control an average current flowing through the light source to a target current level. The driving signal is generated based on one or more signals selected from the first signal, the second signal and the third signal.

Abstract: A multilevel converter has a plurality of converter strands, which are connected to the phases of a three-phase-network in a star or delta connection. From phase voltage values and phase current values, an active component characteristic of the overall active current and two asymmetrical components characteristic of a distribution of the overall flowing active and reactive currents are determined. The active and the two asymmetrical components are each filtered and multiplied with the phase voltage values and the two filtered asymmetrical components. The multiplied values are then weighed and added to the phase current values. From the asymmetrical components and the phase voltage values, a zero current is determined and added to the phase current values such that it symmetrizes a potential asymmetrical active current flow that would occur without the zero current. From the modified phase current values, a control state for the converter strands is determined.

Abstract: A bridgeless power factor correction (PFC) circuit, which includes an alternating current power supply module, a power module, and a control module; the power module includes one or more interleaved PFC circuits, each interleaved PFC circuit includes one inductor, one pair of first switching components, and at least one capacitor, a first end of the inductor is connected to the alternating current power supply module, and a second end of the inductor is connected to one end of each capacitor through one of the first switching components and is also connected to the other end of each capacitor through the other one of the first switching components; and the control module samples a current of each first switching component in the power module, and turns off a first switching component through which a negative current flows.