Abstract: A portable charger is provided for charging electronic devices from a rechargeable internal battery. To accommodate multiple electronic devices, a portable charger unit is combined with multiple power output connection interfaces for connecting to more than one electronic device, as necessary, including connector cables attached to the charger housing or power connection ports. The charger also includes at least one power input connection interface for recharging the internal battery from an external power source, including an AC wall plug interface and a DC car charger interface, each connected to the charger housing and movable between a retracted, storage position and an extended use position. The power output connector cables can also be stored within storage cavities formed in the charger housing when not in use and extended therefrom for connection with electronic devices in need of recharging. The power connection ports can act as power inputs, power outputs, or both.

Abstract: Methods, and apparatus for determining inertia within a synchronous area of an electric power grid are described. A frequency characteristic relating to a frequency of electricity flowing in the electric power grid is measured, a magnitude relating to a power flow modulation is determined based on data relating to power characteristics of one or more power units arranged to consume electric power from and/or provide real and/or reactive electric power to the electric power grid, and a frequency response characteristic associated with at least one area of the electric power grid is determined on the basis of the measured frequency characteristic and the determined magnitude characteristic. This enables frequency response characteristics within a synchronous area of the electric power grid to be easily determined.

Abstract: The present invention relates to methods and corresponding apparatus for regulation, control, and management of DC-to-AC, AC-to-DC, and/or DC-to-DC switching power conversion.

Abstract: Apparatus for power conversion are provided. One apparatus includes a power converter including an input circuit and an output circuit. The power converter is configured to receive power from a source for providing power at a DC source voltage VS. The power converter is adapted to convert power from the input circuit to the output circuit at a substantially fixed voltage transformation ratio KDC=VOUT/VIN at an output current, wherein VIN is an input voltage and VOUT is an output voltage. The input circuit and at least a portion of the output circuit are connected in series across the source, such that an absolute value of the input voltage VIN applied to the input circuit is approximately equal to the absolute value of the DC source voltage VS minus a number N times the absolute value of the output voltage VOUT, where N is at least 1.

Abstract: A load bank for testing power sources includes a load resistor assembly having a plurality of resistors which can be switched between wye and delta configurations for testing a variety of voltages and power sources requiring various load applications. First and second power connections are connected with primary and redundant power sources and a relay alternately connects the first and second power connections with the load resistor assembly for alternately testing the primary and redundant power sources while maintaining the sources electrically isolated. A damper is arranged adjacent the load resistor assembly and is operable between an open position which permits cold air to be delivered to the load resistor assembly to cool the assembly when the load bank is operating and a closed position which prevents hot air from being recirculated when the load bank is not operating.

Abstract: An apparatus and a method for managing the energy supplied to a low-voltage system of a vehicle. The low-voltage system includes a battery, which supplies the first voltage on a low-voltage bus. A system for charging the battery includes an alternator for supplying a charging voltage to the battery, and motor-vehicle loads supplied by the battery and/or by the alternator. A high-voltage system operates at a second voltage higher than said first voltage. The high-voltage system includes the vehicle energy-recovery stage. The second voltage is supplied through an intermediate energy-storage system and a DC-DC converter. A control module that carries out energy-management operations at least by the alternator. The second voltage of the DC-DC converter is regulated via a control procedure of a hysteretic type.

Abstract: Apparatus, systems and methods for managing and distributing electronic device battery power charge to electronic devices having batteries in need of charging. The electronic devices are positioned in proximity to a charge distribution unit (CDU) and a controller, which receive battery signal data including battery power level data transmitted from the electronic devices. Using the battery power level data the controller analyzes the battery signal data to determine an allocated amount of battery power charge required for charging each device battery to a desired battery charge. The CDU receives these allocated amounts and initiates transfer thereof from a power source in communication with the invention. Allocated amount(s) of battery power charge are transferred from the power source by sharing power source charging power amongst the electronic device batteries to ensure each electronic device has available battery power at a time when needed.

Abstract: A DC/DC converter is provided for operation within a narrow voltage range during normal conditions, while allowing for a wider input voltage range for short periods of time. A first switch is coupled across first and second input terminals, and a capacitor is coupled in parallel with the first switch and across the input terminals. A second switch is coupled in series with the first input terminal and between the first switch and the capacitor. Operation of the switches is regulated in accordance with a bypass mode of operation when received input power is within a defined range, and a boost mode of operation when received input power is less than a threshold value, wherein the received input power is boosted to a bulk output power within the defined range. Boost operations may in various embodiments be provided via, for example, a critical conduction scheme or continuous conduction scheme.

Abstract: A method and system for use in controlling an electric network are provided. The system includes an Integrated Volt-VAr Control (IVVC) component configured to determine optimization parameters for slow dynamics electromechanical devices and fast dynamics DER devices coupled to the network. The slow dynamics devices are controlled by a present state of the electric network and a voltage rise table that is adaptively updated in real-time using a command output, or a power flow-based complete optimization routine that generates optimal setpoints for the traditional controllable assets and for at least some of the fast dynamics DER devices. The fast dynamics devices are controlled locally using a control algorithm that uses a reactive power contribution based on IVVC settings, based on photo-voltaic (PV) plant active power variations, based on power factor, or based on a voltage of the local electric network.

Abstract: In one embodiment, a method includes obtaining a first value indicative of an amount of power available to a device from a power source, obtaining a second value indicative of an amount of power consumed by the device, and selecting, based on the first value and second value, one or more power consuming functions of the device in order to manage power consumption of the device.

Abstract: A method of stabilizing a DC electricity network, the network including a DC voltage source powering electrical loads that are connected in parallel to terminals of the voltage source and each of which is to receive a current or voltage setpoint. The method stabilizes the network by regulating setpoints applied to the loads by a virtual stabilization impedance generated at terminals of each load, the virtual impedances being dimensioned to stabilize the network in desired operating points and in given configurations of the network including a state in which at least one load is inactive or has failed and a state in which the stabilization of a load is inactive. Each virtual impedance is generated by a non-linear regulation loop acting on the setpoint for the corresponding load.

Abstract: A high-speed low dropout (HS-LDO) voltage regulation circuit suitable to enable a power gate unit to produce a variable voltage signal based on the load of a processor is disclosed herein. In various embodiments, selection logic may dynamically enable or disable the HS-LDO circuit to allow the power gate unit to operate under a fully-on or fully-off mode. Other embodiments may be disclosed or claimed.

Abstract: A system for controlling voltage for an electric power system comprising: at least two substations and at least one load using voltage control devices, with one voltage control module required for each substation with appropriate control elements for OLTC equipped transformers or turbo generator's automatic voltage regulators. Utilizing the system, methods of the like have the purpose of controlling the distribution of reactive power to minimize power losses, maintain each busbar voltage in accordance to selected set point, maintain active and reactive power reserves, and minimizing the reactive power drawn from the transmission system.

Abstract: A converter includes an inductor configured to receive an input signal and output configured to supply an electrical load with an output signal. The converter operates to charge the inductor until a maximum pre-set current value is reached during a first operating condition in which the electrical load is not supplied. Next, the converter actively supplies the electrical load by partially discharging the inductor during a first time interval of a second operating condition. Then, the converter passively supplies the electrical load by the residual charge of the inductor during a second time interval, subsequent to the first time interval, of the second operating condition, by discharging the inductor completely.

Abstract: An uninterruptible power supply (UPS) system (100) comprises a plurality of UPS units (UPS-1, UPS-2) connected in parallel. Each UPS unit comprises a power converter (124) for supplying a share (i load 1, i_load_2) of a total load current (i_tot). The total load is shared automatically between UPS units of power ratings, in a proportionate manner. A controller 130 of each converter is arranged to establish real-time feedback control of a current supplied by the power converter. An exchange current (i_exch) for each converter represents an imbalance between an output current of the converter in question and output currents of the parallel converters. Exchange current sensing circuits of the parallel-connected UPS units are connected together. The controller steers the exchange current of each converter toward a value (i_exc_c) that is a non-zero proportion of a current (i_mut) sensed within the converter.

Abstract: A vehicle electrical system includes a first partial electrical system having a first energy store of a first nominal voltage level, a second partial electrical system having a second energy store of a second nominal voltage level, and a DC-DC converter between the two partial electrical systems. The first energy store has a housing, which has at least a first tap for the first nominal voltage level, and by which a first DC-DC converter can be electrically supplied. The housing has at least a second tap for the second nominal voltage level, by which the second energy store can be electrically supplied. The housing further includes a voltage conversion unit, by which the voltage of the first nominal voltage level can be converted into voltage of the second nominal voltage level.

Abstract: A method for improving an efficiency of a radio-frequency amplifier includes following steps. A set of predetermined parameters are set. A total circuit parameter is calculated according to the set of the predetermined parameters. A switch stress of a power switch is calculated according to the set of the predetermined parameters and the total circuit parameter. A first curve graph is made according to a duty cycle corresponding to the switch stress. The efficiency is calculated according to the set of the predetermined parameters and the total circuit parameter. A second curve graph is made according to the duty cycle corresponding to the efficiency of the radio-frequency amplifier. A value of the duty cycle is selected according to the first curve graph. The efficiency corresponding to the value of the duty cycle is obtained according to the second curve graph.

Abstract: A method for operating a first energy generator in an electric power supply system to which a plurality of electric consumers and at least the first energy generator, which is embodied as a regenerative energy generator, are connected via respectively one grid connection point each assigned thereto, wherein at least the first energy generator has an inverter of predetermined power rating, the AC voltage output is electrically connected to a first grid connection point assigned thereto, and wherein the operating control of the inverter regarding its reactive power feed and/or its reactive power draw into or out of the electric power supply system takes place depending on a continuously measured mains voltage value. The reactive power control in the energy grid is improved in that the mains voltage value is measured at a second grid connection point, which is different from the first grid connection point of the energy generator.

Abstract: A voltage regulator provides a regulated output voltage [108] from an input voltage [100] using control unit [106] to control a switched capacitor circuit [102] to periodically produce different output voltage levels Vx followed by a low pass filter [104] to give a regulated output voltage. Phase interleaving is used where the phases of different voltage levels are interleaved allowing for increased effective switching frequency and reduced switching losses. By controlling the average voltage on the flying capacitors, output voltage is regulated by modulating the resistance of the switches using a duty cycle. A control unit [106] is used to determine the operation region of the voltage regulator device and configure the switched capacitor circuit in each operation region. The controller contains a state machine that determines the switches configuration in each phase of a complete switching cycle.

Abstract: A fuel cell voltage recovery system includes a fuel cell stack having a fuel cell stack voltage between fuel cell stack terminals which is at a first voltage during normal fuel cell operation. The system also includes a high voltage electrical system operating at a first DC operating voltage that is generally higher than the first voltage of the fuel cell stack. A boost converter in electrical connection with the fuel cell stack and the high voltage electrical system operates in a normal control mode to transfer electrical power from the fuel cell stack to the high voltage electrical system through regulation and control of average stack output current (boost input current) during normal fuel cell operation. The boost converter can also operate in a voltage control mode to lower the fuel cell stack voltage to a second voltage that is lower than the first voltage. A FCS controller controls the operation of the boost converter.

Abstract: Method and system for distributing and/or controlling an energy flow to a cluster of a plurality of nodes in an electricity network, wherein each node has an associated status, taking into account constraints relating to the energy delivered to the nodes and constraints relating to the electricity network, comprised of: allocating a local agent to each node of the cluster of a plurality of nodes, wherein the local agent receives a priority for energy to be delivered; allocating a regional concentrator agent to the regional network, comprising at least a part of the cluster, wherein a total of the at least one regional network forms the electricity network; receiving by the at least one regional concentrator agent, the priority for energy to be delivered among the nodes and determining an aggregate priority for energy to be delivered to the at least one regional network, depending on voltage limitations.

Abstract: A power management system having: a power supply unit; a power meter that detects the total power consumption of power supplied from the power supply unit; a plurality of current sensors that each detect the current flowing to a plurality of power consumption units connected to the power supply unit; and a control unit that calculates the power consumption of each of the plurality of power consumption units by using the power meter and the plurality of current sensors. A power outlet unit having: an outlet to which power is supplied from the power supply unit; a current sensor that detects the current flowing through the outlet to the power consumption unit connected to the outlet; and a transmission unit that sends current detection results from the current sensor to the power supply unit.

Abstract: The method for controlling an electrolysis system (1) having a plurality of electrolyser modules (2) and designed to cooperate with a system (3) for supplying electric energy which uses an intermittent energy source includes: determining (E1) an available electric power which the electric energy supply system (3) can provide; evaluating (E2) a suitable number Ne of electrolyser modules (2) to be used according to the available electric power; selecting (E3) electrolyser modules (2) to be supplied electrically, taking into account the number evaluated Ne; determining (E4) the temperature of each electrolyser module selected; and electrically supplying (E5) the selected electrolyser modules (2) by the electric energy supply system according to a distribution of the available electric power depending on the temperatures determined (E4) of each of the electrolyser modules selected.

Abstract: A multi-power factor controller including k measuring units, to which k loads and a power supply path are connected, each of the k measuring units being connected with each of the k loads and measuring a power factor calculation parameter of a connected load; n condensers; n contactors, each of the n contactors including k electromagnetic contactors, connected to the k loads and one of the condensers; n relay units, each of the n relay units having k relays, respectively connected to the k electromagnetic contactors, for deciding whether to turn on or off the electromagnetic contactors; and a multi-power factor control unit for controlling a corresponding relay to turn on the electromagnetic contactor to which the first condenser and the target load are connected.

Abstract: Provided are a monitoring system and a monitoring method. The monitoring system includes a monitoring center, N data transmission systems each in communication with the monitoring center, and N data control systems each in communication with the monitoring center, with the N data control systems corresponding one-to-one to the N data transmission systems. With the monitoring system, it is possible to monitor, at anytime and anywhere, the project service and operation conditions of N solar systems arranged at different locations, timely acquire the real-time operation information of the N solar system monitoring devices arranged at different locations, and conduct, according to such information, remote and centralized control over the solar system monitoring devices. The monitoring system enhances the controllability of the solar system monitoring devices, saves and reduces the maintenance costs, improves the scientific management level, and also has functions of energy saving and environment protection.

Abstract: A switching power supply apparatus, including serially-connected first and second switching elements, a series circuit of a resonant inductance and a resonant capacitor connected in parallel to the first or second switching element, first and second capacitors respectively connected in parallel to the first and second switching elements, and a switching control circuit that alternately turns on the first and second switching elements. The switching control circuit includes a load detection circuit detecting a load state, a burst control circuit that switches to a burst control mode when the load detection circuit detects a light load, and a detection circuit that detects a timing at which a high-side reference voltage at a connection point between the first and second switching elements has a lowest value. The burst control circuit switches from switching stop to switching operation of the first and second switching elements at the detected timing.

Abstract: An approach is provided in which an emergency electrical distribution system detects an environmental alert invoked by an environmental sensor located in a particular location of building structure. The emergency electrical distribution system selects specific electrical source connections in proximity to the environmental sensor and, in turn, terminates electrical power to selected specific electrical source connections.

Abstract: A semiconductor device for limiting inrush current in hot-swap applications includes a power transistor and a current sensing circuit. The power transistor has a first terminal, a second terminal and a control terminal, wherein the first terminal is configured to receive an input voltage from a power supply, the second terminal is configured to provide an output voltage to a load, the control terminal is configured to receive a control voltage. Under regulation of the control voltage, the output voltage increases gradually towards the input voltage during a startup period and becomes substantially equal to the input voltage in a steady state. The current sensing circuit senses the current flowing through the power transistor and generates a current sensing signal. In order to achieve current balance, the control voltage is adjusted based on the relationship between the current sensing signal and current sensing signals of other semiconductor devices connected in parallel with the semiconductor device.

Abstract: A sharing criteria metric is received for each of three phases of a three-phase power. Loads on power converters receiving the three phase power are adjusted based on the sharing criteria metric of each of the three phases.

Abstract: According to one embodiment, a power supply circuit is adapted to turn on a switching transistor connected between an input terminal and an output node and supply current via an inductor to a capacitor connected to the output node, so as to obtain an output voltage from an output terminal connected to the capacitor. A detection signal according to current flowing in the inductor or a detection signal according to a comparison result between the output voltage and a reference voltage are detected at a predetermined time, and an ON-time of the transistor is controlled in accordance with the detection signal.

Abstract: A power bank is disclosed. The power bank includes a voltage output port arranged to provide a first voltage level, and a voltage-controllable and current-bidirectional port arranged to selectively transit a first communication protocol. When the voltage-controllable and current-bidirectional port is arranged to transit the first communication protocol, the voltage-controllable and current-bidirectional port is arranged to output a second voltage level according to the first communication protocol.

Abstract: There are provided a method, a computer program product, and a system for maintaining a materialized view defined on a relation of a relational database. The method includes the step of performing content-based filtering on the relation to identify an update to the relation as being irrelevant with respect to the materialized view.

Abstract: An integrated circuit includes: a voltage converter to receive a first supply voltage signal via a first power path and to output a first output voltage signal; and a voltage regulator to receive the first output voltage signal and to output a regulated voltage signal. The voltage regulator may further be configured to receive the first supply voltage signal via a second power path, and to selectively output the regulated voltage signal from one of the first supply voltage signal and the first output voltage signal.

Abstract: An apparatus includes a current sensor configured to couple to a power source and to sense a present current draw on the power source by a powered device. A voltage converter is coupled to the current sensor. The voltage converter includes an output line configured to couple to the powered device to provide an output charge to the powered device. The voltage converter is configured to adjust the output charge in relation to the sensed present current draw on the power source.

Abstract: In one embodiment, a temperature management system comprises a plurality of temperature sensors on a chip, and a temperature manager. The temperature manager is configured to receive a plurality of temperature readings from the temperature sensors, to determine a plurality of power values based on the temperature readings, to determine a plurality of temperature values based on the determined power values, the determined temperature values corresponding to a plurality of different locations on the chip, and to estimate a temperature of a hotspot on the chip based on the determined temperature values.

Abstract: In an automotive vehicle inverter control apparatus of the related art, a limp-home mode is provided, but six power sources including transformers are required for respective gate circuits of the respective IGBT drive circuits. Therefore, a reduction in size and a reduction in weight cannot be achieved, and a demand of the improvement of mountability or the improvement of fuel consumption as described above cannot be satisfied. A power semiconductor module and the drive circuit include three unit semiconductor modules and three unit drive circuits corresponding to a three-phase alternating current, and power supply units of the unit drive circuits are provided independently, whereby the limp-home mode is provided and in addition, the number of power supply units may be reduced, so that the reduction in size and the reduction in weight are achieved.

Abstract: An apparatus, method, and system for a low current led fixture internal auxiliary power supply capable of supplying a low DC voltage output on the order of 1-50 VDC from a voltage input ranging from 15 VDC to 1000 VDC.

Abstract: A bridge rectifier having AC voltage terminals, two DC voltage terminals, and a number of half-bridges corresponding to the number of AC voltage terminals. Each half-bridge has two activatable switching elements, connected in series between the DC voltage terminals and between which one of the AC voltage terminals is connected in each case. Each half-bridge includes a control circuit configured to detect an output voltage applied between the DC voltage terminals and switch a first switching element of the two switching elements of the particular half-bridge to be conductive by activation using a first control signal until the output voltage falls below a lower threshold value, after it has previously exceeded an upper threshold value, and to activate it in a clocked manner by activation using a second control signal, until the output voltage exceeds the upper threshold value, after it has previously fallen below the lower threshold value.

Abstract: In this control method for controlling the electrical power delivered over an electrical supply network (20) by at least two sources (16) of electrical energy, each energy source (16) comprises a storage member (22) for storing electrical energy. The method includes for each energy source (16) the following steps: the application by the electrical energy source (16) of an alternating current voltage signal over the electrical supply network (20); the measurement of an associated electrical power; the determination of an electrical energy stored in the storage member (22); the calculation of a set point value for the voltage signal parameter as a function of the measured power; the modification of the voltage signal, the value of the voltage signal parameter being modified so as to be equal to the calculated set point value. During the calculation step, the set point value is calculated additionally as a function of the stored electrical energy determined.

Abstract: A method may comprise receiving a first clock signal; receiving a digital duty cycle value; using the first clock signal and digital duty cycle value to generate a digital pulse width modulation (DPWM) signal having a plurality of discrete steps to control a switch of a switched-mode power supply; and using a voltage control circuit to modify a duration of each of the plurality of discrete steps of the DPWM signal, wherein the voltage control circuit is configured to receive an analog voltage input.

Abstract: A multi-rail switching converter providing a plurality of output voltages has a master switching circuit, a plurality of slave switching circuits and a control circuit. The control circuit has an interleaving control circuit, the interleaving control circuit judges a phase zone of a corresponding slave switching circuit based on a switching control signal of the master switching circuit and a set signal of the corresponding slave switching circuit, and adjusts a turn-ON moment of the corresponding slave switching circuit based on the phase zone of the corresponding slave switching circuit.

Abstract: A system for providing power over Ethernet emergency lighting is disclosed. The system includes a rechargeable battery pack that is charged without interfering with data signals present on a power over Ethernet link that provides normal lighting. The system includes a power loss monitor for monitoring the presence of normal lighting power present on a power over Ethernet link without interference.

Abstract: An HVAC controller, a method for operating a HVAC unit and a HVAC unit are disclosed herein. In one embodiment, the HVAC controller includes: (1) a memory configured to store a unique default network address for the controller and (2) a processor configured to automatically generate the unique default network address based on a seed value that is uniquely associated with the HVAC unit.

Abstract: A consumer apparatus operation management system that prepares an operation plan of a consumer control apparatus in a power distribution system includes: an evaluation unit configured to acquire system information including a system topology and impedances in the power distribution system, to predict load amounts and power generation amounts for respective prescribed nodes, to generate a voltage distribution profile indicative of a correlation between a power transmission distance and a voltage transition based on the system information, the load amounts, and the power generation amounts, and to figure out an evaluation value based on a variation width of the voltage distribution profile and a specified voltage width; and a preparation unit configured to prepare an operation plan related to heat quantity control and/or electric-energy control in the consumer control apparatus based on the evaluation value.

Abstract: A method and apparatus for adjusting the charge for a battery under a power sharing arrangement is disclosed. In one embodiment, the method comprises determining if power output capacity of an alternating current (AC) adapter is less than or greater than a system power requirement for a system that receives power from the AC adapter and a battery, determining a charge current for charging the battery from the AC adapter, based on a voltage range of the battery, the current charge being less than excess current available from the AC adapter in view of determining that the power output capacity of the AC adapter is greater than the system power requirement, and controlling a battery charger to charge the battery with the charge current by specifying the charge current to the battery charger if the power output capacity of the AC adapter is greater than the system power requirement.

Abstract: A power management device includes at least one switching regulator to generate a conversion voltage from an input voltage, a plurality of low drop-out regulators to generate a plurality of output voltages from the conversion voltage, and a controller to estimate drop-out voltages of the low drop-out regulators based on output currents of the low drop-out regulators and to dynamically control the conversion voltage based on the estimated drop-out voltages.

Abstract: The invention relates to a DC power distribution system, especially an EMerge DC power distribution system (1). The system is adapted such that power conductors (3, 4) electrically connected to different groups (5, 6) of ports (14) belong to separate power line communication (PLC) channels, wherein several electrical loads (7 . . . 10; 11 . . . 13) are in power line communication with a group of ports of a same PLC channel. The separation of the different PLC channels allows for a relatively simple determination to which group of ports which electrical loads are electrically connected. This information can be used by, for instance, a user to commission the electrical loads. For example, if the locations of the power conductors, which are electrically connected to certain groups of ports, are known, the information about which electrical loads are connected to which groups of ports can be used for determining the location of the respective electrical load.

Abstract: The problem arises of how to control a plurality of hydraulic pumps to achieve desired performance criteria, such as reduced wear and/or power consumption. The hydraulic pumps are operated in a hydraulic system for delivering hydraulic fluid to a hydraulic motor in a cryogenic pumping apparatus in an engine system fuelled with a gaseous fuel. A controller is operatively connected with the plurality of hydraulic pumps and is programmed to periodically determine a priority for each hydraulic pump as a function of predetermined criteria such as respective cumulative pumping cycles. Higher priority hydraulic pumps are operated before lower priority hydraulic pumps, that is in descending order of priority, to supply hydraulic fluid to the hydraulic motor. Hydraulic pumps are selected to operate according to the desired performance criteria.

Abstract: An image forming apparatus comprises a first circuit unit including a control unit and a second circuit unit having a driving unit. The apparatus generates, by a power-supply unit, a power-supply voltage necessary for driving the driving unit to supply the power-supply voltage to the driving unit. The apparatus detects a voltage reduction of the power-supply voltage and performs access stopping processing for stopping access of the second circuit unit, based on the detecting of the voltage reduction of the power-supply voltage.

Abstract: Power delivery systems and methods described herein conductively couple several input lines with a cable that conducts a multi-phase electric current. The input lines separately conduct different phases of the electric current. Output lines are conductively coupled with plural machines, and separately conduct the different phases of the electric current. Plural switching devices are conductively coupled with the input lines and with the output lines, and are used to control the switching devices in order to conduct the different phases of the electric current to the machines. A first set of the switching devices is closed to separately conduct the different phases of the electric current to a first machine of the machines. A different, second set of the switching devices is separately closed to separately conduct the different phases of the electric current to a different, second machine of the machines.