Abstract: Methods of powering a radio that is mounted on a tower of a cellular base station are provided in which a direct current (“DC”) power signal is provided to the radio over a power cable and a voltage level of the output of the power supply is adjusted so as to provide a substantially constant voltage at a first end of the power cable that is remote from the power supply. Related cellular base stations and programmable power supplies are also provided.

Abstract: A semiconductor device capable of turning a discharge control transistor off faster while maintaining safety is provided. A control unit, in discharge stopping processing, turns a switching element on and executes a first discharge-stopping mode in which the gate voltage of the discharge control transistor is withdrawn via a load and, at a predetermined discharge-stopping mode switching timing, switches to a second discharge-stopping mode in which the gate voltage of the discharge control transistor is withdrawn directly to a low-voltage power source.

Abstract: A method is provided. The method comprises determining configuration data; wherein the configuration data comprises a resistance of a bypass circuit coupled between a remote radio head and a power cable; using the configuration data, determining the resistance of the power cable coupling a programmable power supply to the remote radio head mounted on a mounting structure, comprising: entering a calibration mode; setting an output voltage of the programmable power supply; measuring an output current of the programmable power supply; storing the output current; and determining the cable resistance; and storing the resistance of the power cable.

Abstract: A method is provided. The method comprises determining configuration data; wherein the configuration data comprises a resistance of a bypass circuit coupled between a remote radio head and a power cable; using the configuration data, determining the resistance of the power cable coupling a programmable power supply to the remote radio head mounted on a mounting structure, comprising: entering a calibration mode; setting an output voltage of the programmable power supply; measuring an output current of the programmable power supply; storing the output current; and determining the cable resistance; and storing the resistance of the power cable.

Abstract: In aspects, the present invention provides a method for controlled energizing of a transformer (150) being connected to a first electrical subsystem (110) through a first circuit breaker (140). The method comprises acquiring electrical current waveform in a first phase of the transformer during a closing operation of the first circuit breaker at an instance for switching determined by a controller (130), determining a first peak (310) in the current in the first phase within a first predetermined time window (Tpw), calculating a first correction factor for adjusting the instance for switching in the first phase, and adjusting the instance for switching based on the calculated first correction factor for performing a next controlled energization at the adjusted instance of switching in the first phase.

Abstract: A method for sensing an output current of a Direct Current-to-Direct Current (DC/DC) converter having an external power stage configured to supply a converted current to an external inductor. During a calibration phase at a first start-up of the DC/DC converter: the method includes injecting a calibration current through a switching node of the power stage and through the inductor; and determining a calibration gain of the DC/DC converter to compensate for DC Resistance (DCR) variation by comparing a gain-adjusted voltage across the inductor with a reference voltage. During a measurement phase, the method includes reducing ripple voltage of a switching voltage at the switching node to generate a ripple-reduced switching voltage; and sensing the output current based on a DCR-compensated voltage across the inductor, which is a difference between the ripple-reduced switching voltage and an output voltage of the DC/DC converter with compensation for the DCR variation based on the calibration gain.

Abstract: In a drive control apparatus for a multiple-winding motor including a power converter for driving a winding group per each winding group of a multiple-winding motor having a plurality sets of winding groups, a compensation amount calculator obtains, by using a signal of a first controller controlling a first power converter driving a first winding group among the winding groups, a compensation amount for compensating a signal of an other controller controlling an other power converter other than the first power converter, based on the compensation amount obtained by the compensation amount calculator. A signal of the other controller is compensated to control the other power converter, and the first power converter is controlled without compensating a signal of a first controller.

Abstract: A recharging cable is disclosed, applicable to a smart recharging environment capable of self-detection and self-diagnosis, comprising: a cable; a plug, coupled to the cable, and having at least a power line set, and at least a communication line set, the at least power line set having a power line and a ground line, and the at least communication line set providing real-time communication between the recharging cable and a charging control end and a charged end; an electronic chip, located at one of the cable and the plug, the electronic chip being able to detect real-time information of the material property and device property at the charged end to estimate a real-time impedance information of the cable, and in combination with a historic impedance changes of the cable, to estimate an impedance reflection point of the cable related to ageing.

Abstract: An air conditioner includes an outdoor device and an indoor device. The outdoor device includes an outdoor control unit that is operated at the voltage of a smoothing capacitor; a power-supply switching relay to which a signal line is connected; an inrush-current preventing-relay drive unit that is operated when single-phase AC power is supplied between a power-signal common line and the signal line via an outdoor activation relay in the indoor device and the power-supply switching relay; a first inrush-current preventing relay that is connected in parallel with a power supply relay and is controlled by the inrush-current preventing-relay drive unit; and a second inrush-current preventing relay that is connected in parallel with the first inrush-current preventing relay and is controlled by the outdoor control unit. The outdoor control unit closes the second inrush-current preventing relay when the external power supply is interrupted.

Abstract: A method for synchronizing and connecting a first sub power system with a second sub power system with an intelligent electronic device (IED) by use of at least one switching device between the first sub power system and the second sub power system in an electrical power system is provided. The IED monitors power supply parameters such as voltage magnitude, phase and other derived parameters such as voltage and phase differences in the first sub power system and the second sub power system to identify at least one instance for fast bus transfer where the two sub systems have acceptable differences in magnitude and phase. The IED performs phase shifting and voltage magnitude correction in anticipation for synchronizing power supplies on connection at the identified instance.

Abstract: A power supply includes a DC-DC converter, a boost converter, an energy storage element; and a voltage clamping circuit. The DC-DC converter is connected to a power source with an output voltage in a first voltage range. The voltage clamper circuit is configured to discharge at least a portion of energy of the energy storage element and to produce current at a clamped output voltage range that is substantially equal to the first voltage range. The discharged energy provides hold-up time for the power supply.

Abstract: An insulated DC power supply includes a voltage transformer, a switching device and a primary-side regulating circuit. The voltage transformer includes primary and secondary windings and an auxiliary winding. The switching device causes current to flow intermittently through the primary winding. The primary-side regulating circuit receives a voltage proportional to a current flowing through the primary winding of the transformer, and a voltage proportional to a voltage induced in the auxiliary winding of the transformer to generate and output a drive pulse for turning on or off the switching device. The primary-side regulating circuit includes an ON/OFF signal generator circuit and first and second timer circuits. The switching device is turned off upon expiration of the first timer circuit, and the ON/OFF signal generator circuit does not generate a signal for turn-on of the switching device when the second timer circuit expires.

Abstract: A voltage compensation circuit and a control method thereof dynamically compensate a voltage drop caused by supplying power from a first power line to a function circuit. The voltage compensation circuit includes an amplifier, a detection module and a boosting module. The amplifier has an inverting input end coupled to the first power line and the function circuit to be supplied with a load voltage supplying to the function circuit, a non-inverting input end for being supplied with a reference voltage, and an output end coupled to the detection module to output a comparison signal. The boosting module is coupled between the detection module and the inverting input end of the amplifier. The detection module generates compensation voltage information according to the comparison signal. The boosting module outputs the compensation voltage to the inverting input end of the amplifier according to the compensation voltage information.

Abstract: A wind turbine generator park (1) for supplying power to a power system (37), the park having an assigned first droop response characteristic for use in responding to an under-frequency occurrence on the power system (37). The park comprises a first comparator (108) for generating a first signal when the park is operating according to a curtailed condition, a second comparator (100) for indicating that a change in a frequency of a voltage or current on the power system (37) is greater than a first threshold value, and a controller (114) responsive to the first and second signals for controlling the park according to a second response characteristic causing the park (1) to supply an amount of power to the power system (37) greater than the power supplied according to the first droop response characteristic.

Abstract: In one embodiment, an electric power converting device includes a converter which converts a three-phase AC voltage output from a three-phase AC power source, into a DC voltage of each phase of a three-phase AC load, and an inverter which converts the DC voltage converted by the converter, into a single-phase AC voltage of each phase of the three-phase AC load. The converter includes for each phase of an electric power system a circuit which consists of a plurality of switching elements connected in series. The electric power converting device controls on/off of a switching element corresponding to one of phases of the electric power system in the converter such that a voltage which reduces fluctuation of a DC voltage applied between the converter and the inverter and corresponding to each phase of the three-phase AC load is output from the converter for each phase of the electric power system.

Abstract: An integrated circuit controller for a power converter to be coupled to a distribution network is disclosed. An example integrated circuit controller according to aspects of the present invention includes a switching control circuit that outputs a drive signal to control switching of a switch to regulate an output of the power converter. The integrated circuit controller also includes a cable drop compensator that outputs a compensated reference voltage signal to the switching control circuit in response to a switching signal. The switching signal is responsive to the drive signal. The compensated reference voltage signal is representative of a voltage value that is responsive to a distribution voltage across the distribution network and a load voltage across a load to be coupled to the distribution network. The switching of the switch is responsive to the compensated reference voltage signal and a feedback signal.

Abstract: Switching-mode power conversion system and method thereof. The system includes a primary winding configured to receive an input voltage, and a secondary winding coupled to the primary winding and configured to, with one or more first components, generate, at an output terminal, an output voltage and an output current. Additionally, the system includes an auxiliary winding coupled to the secondary winding and configured to, with one or more second components, generate, at a first terminal, a detected voltage. Moreover, the system includes an error amplifier configured to receive the detected voltage and a first reference voltage and generate an amplified voltage based on at least information associated with a difference between the detected voltage and the first reference voltage. Also, the system includes a compensation component configured to receive the amplified voltage and generate a second reference voltage based on at least information associated with the amplified voltage.

Abstract: The present specification provides a cable and a compensation method for transmitting a high speed signal and delivering power. The cable according to one embodiment disclosed in the present specification interconnects a first device and a second device, the cable comprising: a power line for transmitting power from the first device to the second device; and a voltage restorer for restoring voltage loss of the power receiving side of the second device generated based on the voltage drop relevant to the power line.

Abstract: A power supply circuit is disclosed in embodiments of the present invention, which includes: a voltage output device, configured to generate an output voltage; a parasitic resistance, connected between an output end of the voltage output device and an external load, where two ends of the parasitic resistance generate a voltage drop; and a compensation circuit, connected to the output end of the voltage output device and configured to generate a compensation voltage, where the compensation voltage is loaded onto the voltage output device, so as to offset the voltage drop generated by the parasitic resistance, so that a voltage obtained at an input end of the load is roughly equal to the output voltage generated by the voltage output device. The circuit is applicable to improving load regulation of a power supply.

Abstract: A power adapter includes a processing circuit converting mains power to another alternating current (AC) power or a direct current (DC) power, a first output outputting the converted AC or DC power, a sense resistor connected between the processing circuit and the first output for sampling current flowing through the first output and converting the sampled current to a sampled voltage, an amplifying circuit connected to the sense resistor for amplifying the sampled voltage, and a metallic oxide semiconductor field effect transistor (MOSFET). A gate of the MOSFET is connected to the amplifying circuit. A drain of the MOSFET is connected to the first output through a first resistor and grounded through a second resistor. A source of the MOSFET is grounded. A node between the first and second resistors is connected to the processing circuit. The amplifying circuit makes the MOSFET work in a variable resistance region.

Abstract: A method and apparatus for improving power generation in a thermal power plant. A dynamic reactive compensation system is provided and is connected to a high voltage bus or a generator bus of the power plant. The dynamic reactive compensation system comprises power electronic devices and is operable to provide most of the reactive power that is required from the power plant.

Abstract: Various systems and methods are provided for minimizing an inrush current to a load after a voltage sag in a power voltage. In one embodiment, a method is provided comprising the steps of applying a power voltage to a load, and detecting a sag in the power voltage during steady-state operation of the load. The method includes the steps of adding an impedance to the load upon detection of the sag in the power voltage, and removing the impedance from the load when the power voltage has reached a predefined point in the power voltage cycle after the power voltage has returned to a nominal voltage.

Abstract: A controller is disclosed for hybrid systems providing power to an electrical power grid. The controller reduces wear on hybrid systems by having only a fast unit tuned to track fluctuations of a regulation signal in a normal mode of operation. By contrast, the slow unit does not track fluctuations in the regulation signal in the normal mode of operation, which reduces wear on the slow unit. The normal mode of operation is defined by an energy range of the fast unit. Energy band parameters associated with the energy range can be dynamically modified in order to optimize the efficiency of the hybrid system.

Abstract: A power conversion system is described. The power conversion system includes a first power converter coupled to an electrical grid at a first point of interconnection (POI), a first processing device coupled to the first power converter and configured to control operation of the first power converter, and a first power measurement device coupled to the first processing device and configured to collect data associated with power output of the first power converter. The power conversion system also includes a first global positioning system (GPS) receiver coupled to the first processing device and configured to receive location information corresponding to a location of the first power converter and temporal information corresponding to a time at the location.

Abstract: Certain embodiments of the invention may include systems and methods for accelerating volt/VAR load flow optimization. According to an example embodiment of the invention, a method is provided for accelerating load flow for integrated volt/var control (IVVC) optimization. The method can include evaluating load flow on lines of an electrical network, identifying combinable network lines, combining the identified combinable network nodes to reduce network complexity, and determining load flow optimization for IVVC based at least in part on the reduced complexity network.

Abstract: Provided is a power supply system which is capable of controlling a power receive device to have an input voltage or an input current at a predetermined input setting value even when a power supply device and the power receive device are connected to each other with an arbitrary power cable. The power receive device detects the input voltage or the input current inputted through the power cable and transmits a detected input voltage or input current as power-receive side information to the power supply device through the power cable. The power supply device controls the output value of an output voltage or an output current to be outputted to the power cable based on the power-receive side information received through the power cable so that the input voltage or the input current to be inputted to the power receive device is converged on a predetermined input setting value.

Abstract: Regulation of a remote load center voltage from a local location of a voltage regulator and a voltage regulator control using voltage measurements from the remote load center obtained using a metering device at the load center in communication with the voltage regulator control. The metering device may obtain remote voltage information at the load center and communicate such to the voltage regulator control using a direct communications line, a wide area network, or the like. The communications may include electrical (e.g. copper cable), light (e.g. infrared over fiber optics), radio frequency, or the like. The voltage regulator control may be configured to use local measurements and a line drop compensation algorithm in the event that the remote voltage information becomes unavailable.

Abstract: This invention generally relates to cable compensation, and is particularly applicable to cable compensation for an AC-DC voltage converter. In one embodiment, a cable compensation apparatus for compensating voltage drop of a cable connected between an electrical power supply and an electrical device comprises: a first capacitor; a timer circuit to time a predetermined time period; a current source to supply to said first capacitor during substantially said predetermined time period a first current substantially proportional to an output current outputted by the power supply to the cable; and a control circuit to adjust an output voltage outputted by said power supply to said cable dependent on a voltage on said first capacitor. The compensation in some embodiments is programmable by means of a discrete capacitor component.

Abstract: A semiconductor body (1) comprises a first contact pad (2), a second contact pad (3), an integrated circuit (5) and an impedance (4). The integrated circuit (5) comprises a first terminal (6) which is coupled to the first contact pad (2) and a second terminal (7) which is coupled to the second contact pad (3). The impedance (4) additionally couples the first contact pad (2) to the second contact pad (3).

Abstract: 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.

Abstract: Switching-mode power conversion system and method thereof. The system includes a primary winding configured to receive an input voltage, an a secondary winding coupled to the primary winding and configured to, with one or more first components, generate, at an output terminal, an output voltage and an output current. Additionally, the system includes an auxiliary winding coupled to the secondary winding and configured to, with one or more second components, generate, at a first terminal, a detected voltage. Moreover, the system includes an error amplifier configured to receive the detected voltage and a first reference voltage and generate an amplified voltage based on at least information associated with a difference between the detected voltage and the first reference voltage. Also, the system includes a compensation component configured to receive the amplified voltage and generate a second reference voltage based on at least information associated with the amplified voltage.

Abstract: A wind turbine generator derives the gradient of a change in output power of a generator that generates power by rotation of a wind turbine rotor, and determines an increase/decrease in the output power of the generator on the basis of the derived gradient of the change in output power. Then, when the frequency of a utility grid has dropped, power control is performed on the basis of the determination results. Therefore, a decrease in the amount of power supplied to the utility grid can be more effectively compensated for by accurately detecting output power fluctuations of the generator, using a simple configuration.

Abstract: A power source stabilization circuit provided within a chip of an electronic device is provided. The power source stabilization circuit stabilizes a power source voltage supplied to an operational circuit of the electronic device. The power source stabilization circuit includes an amplifier that detects a fluctuation component in the power source voltage occurring in a main power source wiring used to supply the power source voltage to the operational circuit, amplifies the detected fluctuation component, and outputs the amplified fluctuation component, and a stabilization capacitor that is provided between an output end of the amplifier and the main power source wiring and supplies to the main power source wiring a current to reduce fluctuation in the power source voltage occurring in the main power source wiring, in accordance with the output from the amplifier.

Abstract: A flux control system for a three-phase active voltage conditioner that utilizes an injection transformer to apply calculated compensation voltage to a mains supply. The flux control system is configured to modify the compensation voltage to be applied to at least one primary terminal of the injection transformer so as to avoid magnetic saturation of the injection transformer. The flux control system includes magnetic flux model modules that are configured to calculate a core flux level of the injection transformer, flux offset modules that are configured to apply a first modification to the compensation voltage to gradually reduce any flux offset in the injection transformer, and peak flux modules that are configured to apply a second modification to the compensation voltage to prevent the core flux level from exceeding a preset range.

Abstract: A dynamic voltage compensator for compensating voltage fluctuations in a three-phase power supply system that includes two dynamic voltage restorers (DVR), and two phases are selected arbitrarily from the three-phase power supply system with each selected power supply phase connected in series with one of said dynamic voltage restorers respectively. The dynamic voltage restorers are each used to monitor the voltage between the power supply phase it is connected to and the power supply phase unselected, and to restore the voltage to a normal level when voltage fluctuation is monitored, and at the same time the phase voltage of the unselected phase can also be restored to its normal level. In this way, it can ensure that the phase voltages of the three phases can be restored to the normal level by using only two sets of single-phase DVRs.

Abstract: A DC blocking capacitor and a resistor are coupled in series, and coupled in parallel with an electricity storing section. An ON/OFF circuit and a peak voltage holding circuit are coupled in parallel with the resistor. A current sensing section is coupled in series with the storing section, with its output supplied to the peak current holding circuit. Current from a positive to a negative electrode of the storing section is referred to as a positive direction. The ON/OFF circuit is turned on when the current flows in a negative direction, and is turned off when the current flows in the positive direction. An internal resistor of the storing section is found based on a peak voltage and a peak current resulting from the control and held by the respective circuits. A degree of degradation of the electricity storing section is determined with this internal resistor.

Abstract: Various systems and methods are provided for minimizing an inrush current to a load after a voltage sag in a power voltage. In one embodiment, a method is provided comprising the steps of applying a power voltage (100) to a load (246), and detecting a sag in the power voltage (106) during steady-state operation of the load. The method includes the steps of adding an impedance (RT) to the load upon detection of the sag in the power voltage, and removing the impedance when the power voltage has reached a predetermined point in the power voltage cycle after the voltage has returned to normal.

Abstract: An integrated circuit controller for a power converter to be coupled to a distribution network is disclosed. An example integrated circuit controller according to aspects of the present invention includes a switching control circuit that outputs a drive signal to control switching of a switch to regulate an output of the power converter. The integrated circuit controller also includes a cable drop compensator that outputs a compensated reference voltage signal to the switching control circuit in response to a switching signal. The switching signal is responsive to the drive signal. The compensated reference voltage signal is representative of a voltage value that is responsive to a distribution voltage across the distribution network and a load voltage across a load to be coupled to the distribution network. The switching of the switch is responsive to the compensated reference voltage signal and a feedback signal.

Abstract: An islanding detection apparatus for a distributed generation power system and a detection method therefor operates a power converter to act as a virtual capacitor or inductor at a frequency close to but unequal to that of a utility power system under abnormal condition of the utility power system. When power failure occurs in the utility power system, only the distributed generation power system supplies power to a load so that a load voltage has been changed in at least one of amplitude and frequency which can be immediately detected islanding phenomenon.

Abstract: Procedures to prevent the disconnection of a park of electricity generators from a network in the event of a voltage sag, through which, upon detection of the sag, the voltage travelling to the network is controlled in proportion to the magnitude of the sag; the active power produced by the park, rather than sent to the network, is thus diverted into to storage and/or energy dissipation equipment, keeping the park voltage at a nominal level. The invention also includes a device for carrying out procedures integrating a bypass, transformer, static inverter, static converter, capacitance and dissipation resistance unit, voltage sag detection circuit and control circuit.

Abstract: This invention generally relates to cable compensation, and is particularly applicable to cable compensation for an AC-DC voltage converter. In one embodiment, a cable compensation apparatus for compensating voltage drop of a cable connected between an electrical power supply and an electrical device comprises: a first capacitor; a timer circuit to time a predetermined time period; a current source to supply to said first capacitor during substantially said predetermined time period a first current substantially proportional to an output current outputted by the power supply to the cable; and a control circuit to adjust an output voltage outputted by said power supply to said cable dependent on a voltage on said first capacitor. The compensation in some embodiments is programmable by means of a discrete capacitor component.

Abstract: DC blocking capacitor and resistor are coupled in series with electricity storing section at its both ends, and ON/OFF circuit is coupled in parallel with resistor. Peak voltage holding circuit is coupled in parallel with ON/OFF circuit, and current sensing section is coupled in series with storing section, and an output from current sensing section is supplied to peak current holding circuit. In the structure of the storage device discussed above, a flowing direction of an electric current from a positive electrode to a negative electrode of storing section is referred to as a positive direction. ON/OFF circuit is controlled such that circuit is turned on when the current flows in a negative direction, and such that it is turned off when the current flows in the positive direction. An internal resistor of storing section can be found based on a peak voltage resulting from the control and held by circuit and a peak current resulting from the control and held by circuit.

Abstract: An integrated circuit package (202) includes a voltage regulator (208) and a power-out pin (236) for coupling to a load circuit (210) via a connection (234) external to the integrated circuit package and for coupling to an output (230) of the voltage regulator via a connection (224, 228, 226 and 231) internal to the integrated circuit package. The internal connection has a series resistance that causes a voltage drop due to a load current. The voltage regulator compensates for the voltage drop in the internal connection using a current feedback circuit, in which the current fed back is proportional to the voltage drop caused by the series resistance of the internal connection.

Abstract: Systems and methods of dynamic reactive power support for a power transmission system are provided. In one embodiment, a method of dynamic reactive power support for a power transmission system includes at least one circuit breaker connecting a shunt capacitor bank containing at least one shunt capacitor with a metal oxide varistor (MOV) connected in parallel. A controller is used to detect a voltage drop at the power transmission system (e.g., substation bus). In response to detecting the voltage drop, the controller closes the circuit breaker(s) connecting the shunt capacitors to the power transmission system. The controller then monitors at least one MOV to detect a current flow. Upon detection of a current flow in the MOV, the controller disconnects one or more shunt capacitors from the power transmission system by opening one or more circuit breakers. The shunt capacitors may be disconnected simultaneously, sequentially, in groups, or otherwise.

Abstract: A voltage sag compensation system includes a capacitor charging and discharging module connected to an AC rectifier and to an inverter, a two stage voltage detector configured to detect a degree of voltage sag that is present on a power line, and an inverter gating module selectively connectable to the power line in response to the two stage voltage detector and configured to provide gating signals to the inverter. The system further includes a low DC bus switch out module configured to monitor an output voltage of the capacitor charging and discharging module and to disable the inverter gating module from providing the gating signals to the inverter when voltage associated with the capacitor charging and discharging module falls below a predetermined value.

Abstract: A method for cable resistance cancellation. A single remote sense line and a simple cable resistance cancellation network are leveraged in a power supply unit to compensate for the total cable voltage drop, while maintaining tight output accuracy. By completely compensating for the voltage drops, the wire gauge for the main power wires can be reduced, thereby allowing the use of smaller diameter cables.

Abstract: A voltage sag compensation system includes a capacitor charging and discharging module connected to an AC rectifier and to an inverter, a two stage voltage detector configured to detect a degree of voltage sag that is present on a power line, and an inverter gating module selectively connectable to the power line in response to the two stage voltage detector and configured to provide gating signals to the inverter. The system further includes a low DC bus switch out module configured to monitor an output voltage of the capacitor charging and discharging module and to disable the inverter gating module from providing the gating signals to the inverter when voltage associated with the capacitor charging and discharging module falls below a predetermined value.

Abstract: In a DC regulated power supply realized as AC adapter or the like by a switching power supply, a reference voltage correction circuit, which estimates a voltage drop corresponding to a load current, corrects to increase an output voltage by changing a feedback reference value for regulation of the output voltage from a reference voltage source, in accordance with the load current sensed by the load current sensing circuit. Therefore, there occurs no negative effects that would be caused when output sensing wires are routed to a remote load. In addition, unlike the arrangement in which a reference-use rectifying circuit as well as a load-use rectifying circuit are provided, the arrangement of the switching power supply is not complicated. That is, in correcting a voltage drop, which occurs in power supply lines, corresponding to the load current, it is possible to easily perform a stable output voltage control unaffected by wire routing.

Abstract: High impedance fault detection uses, in addition to sensors that measure purely electrical (i.e., current and voltage), molecule sensors are provided in an electrical grid. These molecule sensors are sensitive to the surrounding environment and may detect one or more of a variety of molecules, such as ozone (O3), combustion gases (carbon monoxide, carbon dioxide and oxygen levels), and odor molecules (ammonia, sulfur dioxide, burned hair/feather, burned proteins, and the like), depending on the type of environmental phenomena that may be expected in a particular location of the sensor(s). These sensors, in combination with conventional electrical sensors, provide a more complete set of data for evaluation and localization of a potential high impedance electrical fault. The use of such sensors is especially useful in confined areas like underground parking lots, substations, and the like.

Abstract: Voltage compensating circuits are connected serially to a power system, including capacitors each having different charging voltages (in relationship of approximately 2k (K=0, 1, 2, . . . ) times the smallest charging voltage value). The voltage compensating circuits convert DC voltages in the capacitors into AC voltages and output the AC voltages, respectively. The voltages of the capacitors are detected as detected values V1 to V3. The detected values V1 to V3 are used as bit signals for a reference value to check a voltage dip amount of the power system with the reference value and to convert the voltage dip amount into a binary signal. A combination is selected from the voltage compensating circuits in accordance with the binary signal so that the sum of output voltages of the selected voltage compensating circuits compensates the voltage dip of the power system.