Abstract: A method for a direct current (DC) islanding detection based on positive feedback of a bus voltage at a specific frequency, essentially including three steps: extraction of a specific frequency component of the bus voltage, injection of a disturbance component of the specific frequency, and determination of DC islanding. The extraction of the specific frequency component of the bus voltage and the injection of the disturbance component of the specific frequency constitute a positive feedback mechanism in a power management unit control loop. In a grid-connected mode of a DC grid, the positive feedback mechanism fails due to a control action of a voltage management unit on a bus, and the bus voltage remains stable. In an islanding mode of the DC grid, under an action of the positive feedback mechanism, the power management unit allows the bus voltage to generate a self-excited oscillation at the specific frequency.

Abstract: Provided is a power conversion system. The system includes a DC bus line including a common terminal, a power generation device configured to provide DC power to the common terminal, a first inverter configured to convert a first input power provided from the common terminal into a first AC power and output the first AC power, and a second inverter configured to convert a second input power provided from the common terminal into a second AC power in response to the first input power being greater than a first threshold power while the first inverter operates and output the second AC power.

Abstract: A power supply system includes a plurality of UPSs configured to provide output power to one or more loads using AC power drawn from a supply bus and energy stored at respective energy modules of the plurality of UPSs. Each UPS of the plurality of UPSs comprises a corresponding frequency sensor configured to generate an indication of a frequency of the AC power at the supply bus. The plurality of UPSs comprises a first UPS configured to draw the AC power from the supply bus when the indication of the frequency output by the corresponding frequency sensor for the first UPS satisfies a first frequency priority threshold and a second UPS configured to draw the AC power from the supply bus when the indication of the frequency output by the corresponding frequency sensor for the second UPS satisfies a second frequency priority threshold.

Abstract: Various embodiments include an energy storage system for a hybrid energy system including a an energy storage device configured coupled to an inverter and controlled by a hybrid management system. The hybrid management system may be configured to use energy from the energy storage device to supplement power output of a power generation system to comply with a contract schedule of electric power output by the hybrid energy system. The hybrid management system may be configured to satisfy stable loads of an industrial application with the power generation system and to meet load swings of the industrial application with power output from the storage device. The hybrid management system may be configured to respond to an increasing desired load transient event by disclosing stored energy to follows a ramping profile that substantially matches a gas-turbine alone ramp rate of a gas turbine generator operating in a spinning reserve mode.

Abstract: A control system, apparatus, and method to control load sharing of multiple generator sets of a power supply system are described. Load transient set points to add an individual generator set can include a transient percentage threshold to characterize load transients as a load transient, a transient count threshold, and a transient count time period during which a detected number of load transients is compared with the transient count threshold. A controller can determine whether to add the individual generator set based on whether the detected number of load transients is equal to the transient count threshold within the transient count time period and control addition of the individual generator set responsive to the detected number of load transients equaling the transient count threshold.

Abstract: A multilayer control framework for a power system includes a hybrid storage system (HSS) to store energy using a plurality of energy storage devices; a local controller coupled to the HSS to smooth output power of wind or photovoltaic energy sources while regulating a State of Charge (SoC) of the HSS; and a system-wide controller coupled to the HSS activated upon an occurrence of one or more energy disturbances with a control strategy designed to improve system dynamics to address the one or more energy disturbances.

Abstract: A hybrid power system is disclosed. The hybrid power system may include a primary power source configured to provide a primary power, and an energy storage device coupled to the primary power source, the energy storage device configured to store excess primary power provided by the primary power source. The hybrid power system may further include a variable speed genset, the variable speed genset including a secondary power source configured to operate at a variable rotor speed to provide a secondary power responsive to power requirements of a load. The hybrid power system may also include a central controller communicatively coupled to the primary power source, the energy storage device, and the variable speed genset, the central controller configured to control the primary power source, the energy storage device, and the variable speed genset based on the power requirements of the load.

Abstract: Example energy management systems and methods are described. In one implementation, a system includes an inverter and a combiner module coupled to the inverter. The combiner module receives DC signals from multiple DC sources and delivers a DC output signal. A control module manages a voltage and a current associated with the DC output signal delivered by the combiner module.

Abstract: A system includes at least one generator coupled to an island grid, at least one energy storage unit and at least one converter coupled to the at least one energy storage unit and configured to be coupled to the island grid. The system further includes a control circuit configured to cause the at least one converter to transfer power between the at least one energy storage unit and the grid responsive to a change in a load on the island grid to maintain operation of the at least one generator at a predetermined operating point. The at least one generator may include a control system configured to match generator output to the load and the control circuit may be configured to maintain the control system of the at least one generator within a predetermined dynamic response capability limit responsive to the change in the load.

Abstract: A power supply device includes: an input determination section configured to determine which one of a commercial power supply and a power generator is an input power supply, and to generate a determination signal; a conversion section of a switching type configured to convert an input voltage into an output voltage; and a drive-signal generation section configured to be supplied with determination output from the input determination section, and to generate a switching drive signal for the conversion section, the drive-signal generation section being configured to serve as a power-factor correction control section and to generate the switching drive signal when the determination signal indicates that the commercial power supply is the input power supply, and being configured to serve as a maximum power point tracking control section and to generate the switching drive signal when the determination signal indicates that the power generator is the input power supply.

Abstract: Aspects of the invention are directed to power distribution systems and methods for distributing power from a primary power source and a backup power source to a load. In one particular aspect, a power distribution system includes a first input to receive input power from the primary power source, a second input to receive input power from the backup power source, an output that provides output power from at least one of the primary power source and the backup power source, a first switch operatively coupled to the first input and the output and operative to selectively couple the first input to the output, a second switch operatively coupled to the second input and the output and operative to selectively couple the second input to the output, and a controller operatively coupled to the first switch and to the second switch and configured to control the first switch and the second switch to provide an electrical interlock.

Abstract: A rectification processor includes rectifier elements that control charge to batteries independently for each of the batteries. A charge-state detector detects charge states of the batteries from their voltages, and determines whether to select the batteries for charging in a half-cycle determined beforehand in accordance with the detected result. A synchronous signal detector detects a signal synchronized with the phase of the 3-phase alternate current (AC) generator from the 3-phase AC generator, and outputs a synchronous signal. A charge controller controls the charge in the rectification processor in synchronization with the 3-phase AC generator according to the synchronous signal from the synchronous signal detector, and, in accordance with the charge states of the batteries output from the charge-state detector, controls charge amounts to the battery/batteries that was determined for selection.

Abstract: A modular portal system and method for harvesting energy from distributed power sources. The distributed power sources include renewable and nonrenewable energy sources, which are coupled to a backplane. The backplane receives modular preconditioner modules and inverter modules, which are inserted into module slots. The preconditioner modules receive power from the distributed power sources via backplane connections and output conditioned DC power to a DC bus on the backplane. The inverters are coupled to the DC bus, receive the DC power, and convert the DC power to AC power. The backplane also includes a controller for selectively coupling the energy harvesting system to a power grid. The AC power generated by the inverter is selectively applied to the power grid and to local loads.

Abstract: A load driving circuit that generates a desired voltage waveform to drive a load includes a target voltage waveform output section that outputs a target voltage waveform to be applied to the load. Power supply sections generate electrical power with voltage values different from each other. Negative feedback control sections between the power supply sections and the load supply electrical power from the corresponding power supply sections to the load and execute negative feedback control of a value of a voltage applied to the load for matching the voltage value and the target voltage waveform. A power supply connection section selects one of the power supply sections based on the value of the voltage applied to the load or the voltage value of the target voltage waveform and connects the selected power supply section to the load and disconnects the rest of the power supply sections from the load.

Abstract: An energy storage system includes: a new renewable energy unit generating a new renewable energy power; a DC link connected to the new renewable energy unit and generating a DC link power; a power system connected to the DC link and generating a power system power; a battery connected to the DC link and generating a battery power; an auxiliary power generator connected to the power system, the new renewable energy unit, the DC link, and the battery, respectively, and generating an auxiliary power; and an integrated controller connected to the auxiliary power generator and receiving the auxiliary power. The auxiliary power is selected from one of the power system power, the new renewable energy power, the DC link power, and the battery power.

Abstract: An energy harvesting system and method having improved efficiency. A primary energy harvesting device is used to generate a first electrical output signal. The first electrical output signal is applied to a first switching circuit. A secondary energy harvesting device is used to generate a second electrical output signal that is used to power a second switching circuit. The second switching circuit generates the switching drive signal for the first switching circuit, which in turn generates a final output signal. By using a second energy harvesting circuit operating in connection with a different structure, and a secondary switching circuit, less power from the signal generated by the primary energy harvesting device is needed to power the first switching circuit. This results in a greater percentage of the output power of the first signal being usable by an external device.

Abstract: A power supply control section calculates a target charge/discharge current of a secondary power supply apparatus based on an actual charged amount and a target charged amount of the secondary power supply apparatus, and feedback-controls the stepped-up voltage of a step-up circuit such that an actual charge/discharge current detected by a secondary current sensor coincides with a target charge/discharge current. When the actual charged amount (1) is equal to or greater than the target charged amount, the target charge/discharge current is set to zero to prevent overcharging, and (2) is less than the target charged amount, a target charge current corresponding to a capacity margin of the step-up circuit is set to quickly charge the secondary power supply apparatus. When the output of the step-up circuit has no margin, the target charge/discharge current is set to zero.

Abstract: A multiple power supply integration apparatus measures electric power and stability of power supplies, outputs thereof having irregularity. Based on measured values of the electric power and the stability, certainty of entire supply of the electric power when a use allocation rate of the power supplies is changed is indexed as an evaluation value. The multiple power supply integration apparatus adjusts each converter according to a use allocation rate corresponding to a largest evaluation value, thereby adjusting a magnitude of the electric power supplied from each power supply to a common power line.

Abstract: Power supply devices for vehicle electrical systems in particular, including two voltage systems, i.e., vehicle electrical systems, each having its own generator. The first generator and the battery belong to the same voltage system, and the second generator belongs to the second voltage system. If the two voltage systems were decoupled, the second generator would not have the excitation current required for starting, so means are consequently provided here to connect the second generator to a charge storage device after actuation of the ignition switch, thereby generating an excitation current; this charge storage device may also be the battery of the first voltage system and the connection is kept conductive until the second generator starts and is generating an output voltage.

Abstract: A method of operating a power system is provided. The power system has a plurality of generator sets and a bus. The method monitors the bus and generator sets disconnected from the bus. The method supplies to a control device information associated with the operating state of each of the generator sets and the bus. The method determines a relative frequency mismatch and a relative phase mismatch between the frequency and phase of the bus and a generator, and generates a frequency speed bias and a phase speed bias for the generator. The method adds the frequency and phase speed biases to form a total speed bias, tunes the total speed bias to make the frequency and phase speed biases combine in a complementary manner, and connects the generator to the bus when the voltage, frequency, and phase of the generator are within a permissible range of the bus.

Abstract: A video controller includes a video block that connects to the print control engine and one laser driver. The video block includes a direct memory access (DMA) block, a video processor, a waveform generator including pattern and multiple pulse mode modulation, a frequency synthesizer, configuration registers, and a data bus. The frequency synthesizer connects to the waveform generator. The configuration registers connect to the DMA block, video processor and the waveform generator. The data bus, operative to carry bus control signals, connects the DMA block, video processor, waveform generator, and the configuration registers.

Abstract: A method of operating a power system is provided, the power system having power-system controls. The method may include automatically setting a priority ranking for a plurality of generator units of the power system with the power-system controls based at least in part on an operating parameter of each generator unit indicative of a quantity of work done by the generator unit. The method may also include automatically controlling which of the generator units run with the power-system controls based at least in part on the priority ranking of the generator units.

Abstract: A controllable power supply device with a step-up function including a constant voltage generator, a programmable voltage generator, a first switch and a linear regulator is provided. The constant voltage generator is used to provide an initial voltage. The programmable voltage generator is used to receive the initial voltage and adjust the received initial voltage to boost the initial voltage to a power supply voltage. The first connecting terminal of the first switch is used to receive the initial voltage, the second connecting terminal of the first switch is used to receive the power supply voltage, and the third connecting terminal of the first switch is coupled to one of the first connecting terminal and the second connecting terminal. Therefore, the voltage from the third connecting terminal of the first switch is stabilized and is outputted as the output voltage of the controllable power supply device by the linear regulator.

Abstract: Aspects of the invention are directed to power distribution systems and methods for distributing power from a primary power source and a backup power source to a load. In one particular aspect, a power distribution system includes a first input to receive input power from the primary power source, a second input to receive input power from the backup power source, an output that provides output power from at least one of the primary power source and the backup power source, a first switch operatively coupled to the first input and the output and operative to selectively couple the first input to the output, a second switch operatively coupled to the second input and the output and operative to selectively couple the second input to the output, and a controller operatively coupled to the first switch and to the second switch and configured to control the first switch and the second switch to provide an electrical interlock.

Abstract: A method of managing power resources for an electrical system of a vehicle may include identifying enabled power sources from among a plurality of power sources in electrical communication with the electrical system and calculating a threshold power value for the enabled power sources. A total power load placed on the electrical system by one or more power consumers may be measured. If the total power load exceeds the threshold power value, then a determination may be made as to whether one or more additional power sources is available from among the plurality of power sources. At least one of the one or more additional power sources may be enabled, if available.

Abstract: An independent automatic shedding system that automatically allows any combination of loads to powered under limited power availability (such as a standby power source) without overloading the generator or rewiring, while contributing to the stability of the power grid. A motorized disconnection actuation mechanism under control of a controller disconnects or recloses the contacts of a branch circuit breaker. A sensor detects the presence or absence of a power source and the type of power source, which is classified according to its type. A power source classification program is executed by the controller that interprets the sensor data and causes disconnection or reclosing of the disconnection actuation mechanism depending on a desired status (ON or OFF) of the branch circuit breaker when standby power is available. Conventional circuit protection is provided an optional advanced circuit protection such as ground or arc fault circuit interruption.

Abstract: Aspects of the invention are directed to power distribution systems and methods for distributing power from a primary power source and a backup power source to a load. In one particular aspect, a power distribution system includes a first input to receive input power from the primary power source, a second input to receive input power from the backup power source, an output that provides output power from at least one of the primary power source and the backup power source, a first switch operatively coupled to the first input and the output and operative to selectively couple the first input to the output, a second switch operatively coupled to the second input and the output and operative to selectively couple the second input to the output, and a controller operatively coupled to the first switch and to the second switch and configured to control the first switch and the second switch to provide an electrical interlock.

Abstract: A method and an apparatus can determine the orders (z) of non-characteristic harmonic currents (Ih) of a second power supply grid, which is coupled to a first power supply grid using an HVDCT system. The apparatus and method also compensates for these non-characteristic harmonic currents (Ih), which are produced as a result of distortion (Uh) of the supply voltage (U1) which exists in the first grid because of a low-frequency harmonic and passes through the short coupling. The order (n) of the existing non-characteristic harmonics is determined by a voltage and/or current measurement of the voltage (U1) of the grid, from which order (n) the order (z) of the generated non-characteristic harmonics in the second grid is determined by a provided voltage-symmetry signal (SMG). This order (z) is supplied to filter logic of a compensation system. The energy quality is thus considerably improved, particularly in the case of grids which are not rigid.

Abstract: A novel vehicle power supply system is suggested which receives its voltage supply from a starter/generator which can be used as a generator in normal operation and as a starter when starting, wherein the starter/generator is connected with a 24 volt ring mains as well as with a 24 volt battery via a pulse inverter and a 300 volt DC intermediate circuit and a bidirectional converter. Additional consumers can be supplied with higher voltages than 24 volts and electric control devices can be supplied with voltage, possible via additional converters, from the bidirectional push-pull converter and the 300 volt DC intermediate network. In addition, this vehicle power supply system contains a plug receptacle with a 220 volt 50 Hz voltage.

Abstract: Prior variable speed constant frequency (VSCF) generating systems which utilize an inverter to derive constant frequency power from variable frequency power developed by a generator driven by a prime mover have controlled system output voltage by controlling the excitation of the generator. Such a control technique, however, does not provide voltage regulation of individual phases and minimize undesirable distortion in the system output. In order to overcome the foregoing problem, a control for a VSCF system having a generator and an inverter which receives DC power from a rectifier coupled to the generator controls switches in the inverter to maintain the voltage of the AC power developed by the inverter at a desired level and controls the power applied to an exciter of the generator to maintain the voltage of the DC power at a particular level relative to the voltage of the AC power developed thereby. Distortion in the inverter output is thereby minimized.

Abstract: The outputs of a plurality of modules or generators of electrical energy, such as fuel cells, chemical storage batteries, solar cells, MHD generators and the like, whose outputs are different are consolidated efficiently. The modules supply a power distribution system through an inverter. The efficiency is achieved by interconnecting the modules with an alternating voltage supply and electronic valves so controlled that the alternating-voltage supply absorbs power from modules whose output voltage is greater than the voltage at which the inverter operates and supplies this power as a booster to modules whose output voltage is less than the voltage at which the inverter operates.

Abstract: A high reliability electrical power system is provided with a microprocessor-based control unit which maintains power output and performs control functions for the system which is driven by the power system. A self locking feature prevents the transmission of potentially erroneous control signals if a component of the system being controlled or the control unit fails. The control unit conducts a series of self-test routines which result in the generation of digital key words. If the correct key words are generated and the other circuits of the control unit are operating properly, the control unit output remains operative. If the self test routines detect a failure in the system being controlled or the control unit or if a failure occurs in one of the control unit output circuits, the control unit output is locked into a predetermined state.

Abstract: Electrical line voltage energy from an AC power network is combined with the energy derived from an auxiliary DC voltage source through the primary winding of a transformer to operate an AC load under rated conditions normally associated with its operation by the AC power network alone. The DC voltage is converted to a form compatible with said rated operation of the load under control of AC signals sampled from the AC power network. Line voltage from the AC power network to the transformer primary is blocked when sufficient energy is available from the DC voltage source alone to operate the load.

Abstract: A dual wound stator for a multiphase alternator operating at varying speeds and supplying rectified current at constant voltage with variable output. By combining windings having many turns of smaller wire with windings having fewer turns of larger wire, a compound curve of output is obtained, combing low cut-in speed with high maximum output and increased efficiency.