Abstract: A method for determining a corrected current-voltage curve of an electrical system, the method including the following steps: obtaining a first current-voltage characteristic curve of the electrical system, by varying the voltage across its terminals at a first measurement rate, obtaining a second current-voltage characteristic curve of the electrical system, by varying the voltage across its terminals at a second measurement rate, different from the first rate, using a single notional capacitance to model an intrinsic stray effect to be corrected between an input voltage without the stray effect and the output voltage, determining a correction value representative of the stray effect and a step of determining a corrected current value on the basis of the determined correction value.

Abstract: Systems and methods for operating a cluster transformer operably coupled to cluster of DFIG wind turbines in low-wind conditions are provided. A wind turbine cluster system can include at least one DFIG module, a cluster transformer, and a control device configured to control operation of the cluster transformer based at least in part on a wind parameter. Each DFIG module can include a doubly fed induction generator comprising a rotor configured to generate AC power at a first voltage, a stator configured to generate AC power at a second voltage, and a power conversion system coupled to the rotor to convert power at the first voltage to power at the second voltage. The cluster transformer can be configured to receive power at the second voltage from the at least one DFIG module and convert the power at the second voltage to power at a third voltage.

Abstract: A power converter is provided that includes a detection circuit configured to determine a power source type based on at least one characteristic of power received from a power source. The detection circuit is also configured to determine an operating edge of the soft AC source by monitoring at least one parameter as the soft AC power source approaches a power limit, and assign an operating point to the soft AC power source based on the operating edge to increase power delivery of the soft AC power source.

Abstract: The present invention discloses a feedback type voltage regulator, including a voltage reference circuit for providing a reference voltage, distributed series feedback amplifiers electrically coupled to the voltage reference circuit and a power transistor which gate is electrically connected to the distributed series feedback amplifiers. The distributed series feedback amplifiers comprises three set of amplifiers serially connected with each other, wherein the relation of the gain of the first amplifier (A1), the second amplifier (A2), and the third amplifier (A3) is A1>A2>A3, wherein the relation of the bandwidth of the first amplifier (B1), the second amplifier (B2), and the third amplifier (B3) is B1<B2<B3.

Abstract: Fault Ride Through (FRT) transient management system configured to enhance the FRT capability doubly-fed induction generator (DFIG)-based wind turbines. A grid side converter (GSC) introduces shunt and series compensation for normal operation and voltage dips, respectively. A braking resistor may be added to smooth switching transients from shunt to series interfaces and dissipate excessive power from the GSC. To attain a flexible control solution for balanced and unbalanced fault conditions, the transient management scheme may employ positive and negative sequence controllers. The system dynamics for the series compensation topology may be analyzed using small-signal linear model. Based on the mathematical model, the controller may be tuned to balance voltage regulation performance and transient stability margins with consideration of various operating conditions.

Abstract: A system for delivering power over a network of devices connected through a serial link includes a first and second differential pairs of wires. Each differential pair of wires is double AC coupled by a HPF on one side and by another HPF on an opposite side. An LPF connects a portion of each differential pair of wires between the HPFs to a voltage source, and another LPF connects that portion of each differential pair to a load. The system further includes a third and fourth differential pairs of wires. All four differential pairs of wires are located within a single cable, such as a CAT6 cable. The first, second and third differential pair of wires are used for video links, and the fourth differential pair of wires are used for the bi-directional hybrid link. A power delivery circuit in each device includes a voltage source, a power relay switch, a signature resistor for detection, and a load detector.

Abstract: The present invention relates to a power system utilizing an engine generator or public power with AC source, wherein the power system particularly has the characteristics that the maximum output current thereof is limited by electromagnetic effects, and/or constant current or nearly constant current output thereof is set to be lower than the maximum output current, for powering a load, and charging a battery, or jointly powering a load with a battery; when an engine generator set is utilized to be power supply, during operation, the engine operates with the best brake specific fuel consumption and/or the range of revolutions and torque for better energy saving.

Abstract: A control unit of a system stabilization device uses a fluctuation detection block (60) to determine fluctuation components included in the active component and reactive component currents of a system current and fluctuation components included in the frequency signal and the amplitude signal of a system voltage. The high frequency cut-off of the fluctuation detection block (60) is set to be f1; the low frequency cut-off is set to be f2. The fluctuation detection block (60) is composed of a low-pass filter (61) with a time constant of T1, a low-pass filter (62) with a time constant of T2, a subtracter (63) which outputs the difference, between the output signals of the filter (61) and the filter (62), and a feedback circuit (64) which provides feedback on the output of the subtracter (63) to the filters (61, 62). Thus, stability is ensured without using a current detector.

Abstract: A semiconductor IC device capable of power-sharing includes a first power line configured to be supplied with a first power, a second power line configured to be supplied with a second power, a switching block configured to connect the first power line with the second power line in response to a first control signal, and a power-sharing control block configured to generate the control signal in accordance with a plurality of operation command signals.

Abstract: A multi-rail power-supply system provides power to circuitry requiring at least one additional rail between a high and a low-voltage rail. The system comprises a first power regulator that interconnects the high-voltage rail and an intermediate node and sets a first voltage rail that has a magnitude that is less than the high-voltage rail, wherein current that flows from the high-voltage rail is employed by a first set of peripheral circuitry prior to sinking through the first power regulator to the intermediate node. The system further comprises a second power regulator that interconnects the intermediate node and the low-voltage rail and sets a second voltage rail that has a magnitude that is greater than the low-voltage rail, wherein current that flows from the intermediate node is sourced by the second regulator and is employed by a second set of peripheral circuitry prior to flowing to the low-voltage rail.

Abstract: A state-of-charge equalizing device equalizes the state of charge of each of cells connected in series to form an assembled battery, and comprises charging/discharging circuits connected in parallel to the respective cells to discharge and/or charge the respective cells, voltage measurement circuits connected to the respective charging/discharging circuits to measure the voltages across the respective cells, and a control circuit.

Abstract: A power conversion device including sub-inverters, each connected in series with respective phase of a three-phase main inverter including a smoothing capacitor, which is fed from a power supply via a converter, as a DC input thereof, and feeds power to a load using the sum of outputs of the inverters. A manipulative quantity is determined so that the DC voltage at each of smoothing capacitors which is an input of each of the sub-inverters will follow a command value. The manipulative quantity is added to an output voltage command for the three-phase main inverter, and is subtracted from an output voltage command for the sub-inverters. Thus, power is shifted from the three-phase main inverter to the smoothing capacitors of the sub-inverters.

Abstract: Control modes for operating multiple power sources include energy storage systems and applicable to large systems such as locomotives. Selectable operating modes are provided for different locomotive speed ranges and work loads. A common DC bus electrical architecture is used so that prime power sources need not be synchronized. Multiple-engine locomotives have the engine systems that may be electrically connected in parallel or in series or in combinations of parallel and series to a DC bus.

Abstract: A power system for supplying power to a load is provided. The power system comprises a converter system comprising a first converter and a second converter and configured for operating in a first mode and a second mode. The first converter and the second converter are configured to be coupled in series during the first mode, and in parallel when operating in the fault mode.

Abstract: An energy management controller (EMC) for use with series connected amplifier modules monitors the rail voltage across an energy storage capacitor which drives the amplifier modules, and compares the rail voltage with a reference voltage. The EMC controls the direction of energy flow to either provide power to one of the amplifier modules to add energy to the energy storage capacitor, or to provide power to the load.

Abstract: A motor drive system for driving a single-phase PSC motor, in which the two motor windings are conductively isolated from each other, from a two phase power source. In one embodiment, the PSC motor is supplied from a two phase inverter circuit. The PSC motor is also connectable through a four-pole double-throw switch to either a single phase source including a run capacitor or the two phase inverter circuit.

Abstract: A power supply for supplying power to a switched regulator includes a programmable voltage source 14, a constant voltage source 12 and a programmable switched mode current source 16 connected in series between the positive and negative outputs. A catching diode 18 is connected in parallel with the constant voltage source 12 and the current source 16. The supply operates to provide a controlled current at the output, irrespective of the load voltage.

Abstract: A method of control and a control circuit for use in connecting all or sub-parts of a battery supply to a battery driven motor includes relays connected between a motor and each sub-part of a battery supply; a timer having a predetermined time period and which changes its output condition at the end of each time period; a motor speed selector for selecting either full motor speed or a portion thereof; and a switch arrangement which interconnects the relays, timer and motor speed selector. The switch arrangement provides for a first sub-part of the battery supply to be connected to the motor when the selector is in a less than full speed position and when the timer has one output condition. A second sub-part of the battery supply is connected to the motor when the selector is in a less than full speed position and the timer has a second output condition. The relays connect the full battery supply to the motor when the selector is in a full speed position.