The present invention provides method and apparatus to perform combined cognitive and motor rehabilitation on a computerized non-portable system or on single portable device. A patient can play a variety of games that require the patient to perform a variety of memory exercises which involve physical exertion. The activities of the patient are monitored with pattern analysis software which provides feedback to the patient. The feedback can include voice synthesis, video guidance, progression messages etc. Patient data obtained while the patient is performing each of the memory exercises is stored locally on a database module and then uploaded to a cloud server. A remote psychologist/psychiatrist monitors the patient by logging into the same cloud, and updating cognition exercises. The same therapist can have live chats with the patient for further interaction and coaching.

In one embodiment, an apparatus may receive metadata that is associated with content. The metadata includes event descriptors that describe events included in the content. The apparatus may generate a question based on at least one of the event descriptors.

A device configured to track and capture the movement data of a target as well as shooting and firearm movement activity of a hunter includes a housing, a camera, sensors, a processor, a memory, and a battery. The camera is disposed in close proximity to the housing to capture the movement of a target. One or more sensors are disposed in the housing and interfaced with the processor to capture the velocity and orientation of a gun. A trigger activation sensor is also in communication with the processor. The memory stores camera activity, trigger activity, sensor activities, and also stores an alarm setting on the device. The processor activates the alarm setting when predefined criteria are met. Radar can be incorporated to determine the distance of the target from the user. GPS can also be included to provide precise location and time information.

A new design for a dry-erase board allows for writing on a clear top surface or a second surface under the clear top surface. The dry-erase board includes an insert positioned between the clear top surface and a second surface, the insert being protected by the clear top surface

A communication apparatus with a multiple-input and multiple-output (MIMO) channel, includes a minimum mean square error (MMSE) detector configured to estimate quadrature amplitude modulation (QAM) symbols based on signals received through the MIMO channel. The apparatus further includes a QAM demodulator configured to demodulate the estimated QAM symbols, and estimate a first posterior probability of each of encoded bits of the estimated QAM symbols, and a first module configured to remove a first prior probability of each of the encoded bits from the first posterior probability to generate soft estimates of the encoded bits. The apparatus further includes a channel decoder configured to decode the encoded bits based on the soft estimates, and generate an improved posterior probability of each of the encoded bits, and a second module configured to generate a second prior probability of each of the encoded bits based on the improved posterior probability.

In a data recovery circuit, a sampling circuit is configured to sample data using a plurality of sampling clock signals having different phases relative to one another and to output a plurality of sampled data. A recovery data generation circuit is configured to perform a logic operation on the plurality of sampled data and to generate a plurality of intermediate recovery data according to a result of the logic operation. A recovery circuit is configured to check the plurality of intermediate recovery data for existence of an error and to output intermediate recovery data that is error-free, among the plurality of intermediate recovery data, as recovery data.

Multiple-Input and Multiple-Output (MIMO)-Orthogonal Frequency Division Multiplexing (OFDM) communication is provided which allows high accuracy estimation of frequency offset, high accuracy estimation of a transmission path fluctuation and high accuracy synchronization/signal detection. Pilot symbol mapping is provided for forming pilot carriers by assigning orthogonal sequences to corresponding subcarriers among OFDM signals which are transmitted at the same time from respective antennas in the time domain. Even when pilot symbols are multiplexed among a plurality of channels (antennas), this allows frequency offset/phase noise to be estimated with high accuracy.

A transport stream (TS) generating apparatus, a transmitting apparatus, a receiving apparatus, a digital broadcast system having the above, and a method thereof are provided. The digital broadcast system includes a transport stream (TS) generating apparatus which generates a multi transport stream (TS) by multiplexing a normal stream and a turbo stream having a variable coding rate, a transmitting apparatus which re-constructs the multi TS by processing the turbo stream, and transmits the re-constructed multi TS, and a receiving apparatus which receives the re-constructed multi TS, and decodes the normal stream and the turbo stream respectively, to recover normal data and turbo data. Accordingly, a multi TS, which includes normal stream and a turbo stream of various coding rates, can be transmitted and received efficiently.

A display apparatus includes a display section, a display control section, a distance detection section, and a coordinate detection section. The display section has a display area in which a selection image is displayed. When the selection image is formed by a plurality of images hierarchically associated with one another, the display control section displays consecutively the images configuring the selection image in accordance with the hierarchical association. The distance detection section detects a spatial distance between a pointer and the display area. The coordinate detection section detects coordinates which correspond to a position of the pointer. The display control section displays, together with a specified image displayed at a position corresponding to the coordinates detected by the coordinate detection section, related images in an immediately lower level in the hierarchy associated with the specified image, when the spatial distance detected is shorter than a preset threshold distance.

View definitions are created for deterministic performance analysis in real-time computing systems, and can then be used to present views for analyzing outliers that occur during run-time execution. Trace data created by a real-time application is compared to a set of view definitions to determine whether the trace data matches the view definition. If so, then related records from the trace are gathered according to specifications in the matched view definition, and calculations (such as elapsed time) can then be performed using the related records. A view definition may be created by prompting a user for selection of parameters to be programmatically inserted into a markup language document. A capability may be provided whereby a user can receive additional information (which is extracted from the trace data, according to specifications in the matched view definition) upon a user gesture such as hovering a selection means over a displayed view.

Gesture based interaction with traffic data is disclosed. A virtual broadcast presentation may be generated based on dynamic information such as traffic information, weather information, or other information that may be featured on a virtual broadcast presentation. A gesture made by a user is detected and processed to determine an input command associated with the detected gesture. The virtual broadcast presentation may be manipulated based on the input command.

Sequential write operations to a unit of compressed memory, known as a compression tile, are examined to see if the same compression tile is being written. If the same compression tile is being written, the sequential write operations are coalesced into a single write operation and the entire compression tile is overwritten with the new data. Coalescing multiple write operations into a single write operation improves performance, because it avoids the read-modify-write operations that would otherwise be needed.

Generating a corrected electronic record of a locate and/or marking operation. The operation comprises locating and/or identifying, using a physical locate mark, presence or absence of an underground facility within a dig area. At least a portion of the dig area may be excavated or disturbed. First information relating to a location of the facility and/or the mark is received. Based at least in part on the first information, the location of the facility and/or the mark is represented to generate an electronic visual representation of the operation. Second information relating to a corrected location of the facility and/or the mark is received. Based at least in part on the second information, the corrected location is represented to generate a corrected electronic visual representation of the operation. Third information relating to the corrected representation of the operation is transmitted and/or stored to generate the corrected electronic record of the operation.

A method is disclosed for assessing an aspect relating to a locate and/or marking operation performed by a locate technician based on an electronic representation of the operation. The operation includes locating and/or identifying, using a physical locate mark, a presence or an absence of an underground facility within a dig area. A portion of the dig area may be excavated or disturbed during excavation activities. The method includes digitally representing, on a display device, the facility and/or the physical locate mark to generate an electronic visual representation of the operation. The method further includes determining a length associated with a portion of the digitally represented facility and/or physical locate mark in the electronic visual representation of the operation. The method further includes, based on the determined length, automatically assessing the aspect relating to the operation.

Generating a digital-media-enhanced electronic record of a locate and/or marking operation performed by a locate technician. The locate and/or marking operation comprises locating and/or identifying, using at least one physical locate mark, a presence or an absence of at least one underground facility within a dig area, wherein at least a portion of the dig area may be excavated or disturbed during excavation activities. A location of the at least one underground facility and/or the at least one physical locate mark is electronically rendered on a display device so as to generate an electronic visual representation of the locate and/or marking operation. At least one digital media file representation of a corresponding digital media file relating to at least one aspect of the locate and/or marking operation or an environment of the dig area is also electronically rendered on the display device, so as to generate a digital-media-annotated representation of the locate and/or marking operation. Information relating to the digital-media-annotated representation of the locate and/or marking operation is electronically transmitted and/or stored so as to generate the digital-media-enhanced electronic record of the locate and/or marking operation.

Implementations for exciting two or more modes via modal decomposition of a pulse by a wave launcher are generally disclosed.

Temperature characteristics of battery cells are detected. In accordance with one or more embodiments, an intercept frequency is detected for each battery cell, at which frequency an imaginary part of a plot of impedance values of the battery cell exhibits a zero crossing. The impedance values correspond to current injected into the cell. A temperature of the cell is determined based upon the detected intercept frequency for the cell and stored data that models operation of the cell. Various approaches are implemented with different types of circuits coupled to detect the impedance values of the respective cells.

Circuitry and techniques to measure, at the battery's terminals, characteristic(s) of the charging signal applied to the battery/cell during the recharging operation and, in response to feedback data which indicates the charging signal is out-of-specification, control or instruct the charging circuitry to adjust characteristic(s) of the recharging signal (e.g., the amplitude of the voltage of and/or current applied to or removed from the battery during the charging operation). For example, a rechargeable battery pack comprising a battery, and controllable switch(es), a current meter and voltmeter, all of which are fixed to the battery. Control circuitry generates control signal(s) to adjust a current and/or voltage of the charging signal using the feedback data from the current meter and/or voltmeter, respectively.

A method for operating a driverless, mobile assembly and/or material transport unit as a driverless transport system (DTS) with fixed assembly and/or warehousing stations. In this method, a system control device is used for the entire assembly process. The driverless, mobile assembly and/or material transport units comprises a travel device for the traveling movement of the unit, a drive device for the travel device, an energy storage device for providing the energy for the drive device and a control device for controlling the traveling movement in coordination with the system control device.

An electricity generation device includes a permanent-magnet electric generator with three or more phase windings each having an output terminal and connected to a neutral point, and bidirectional semiconductor switching circuits capable of interrupting connections between the respective phase windings and the neutral point. Each switching circuit allows current to flow in both directions. A gate signal generation circuit outputs to one of the switching circuits during a period including the time at which the AC voltage excited in the corresponding phase winding turns from positive to negative and during a period including the time at which the AC voltage excited in the corresponding phase winding turns from negative to positive. A startup gate signal output circuit outputs a startup gate signal to all of the bidirectional semiconductor switching circuits when the permanent-magnet electric generator is to be started.

Starting and stopping an engine is automatically controlled based on a load without using a relay. An inverter engine-driven power generator has an alternator, a rectifying circuit, a DC/DC converter, and an inverter circuit. A load detection circuit is connected to an output of the inverter circuit in parallel. A load detection line of the load detection circuit is connected to an output line of the inverter circuit in parallel via resistors. A power supply formed of a battery is connected to the load detection line. A decision circuit outputs a load detection signal when a current having a preset value or more flows through the load detection line. A drive/stop CPU starts the engine in response to the load detection. The resistors are set at a resistance value which does not influence a load to which a generator output is supplied.

The excitation overcurrent detection unit for the doubly-fed electric machine is provided with a function to determine an excitation current magnitude relationship among three phases. The firing pulse is held to on-state or off-state to cause the largest-current phase and the second-largest-current phase to charge the DC capacitor by the operation of diodes. The conduction ratio of the third-largest-current phase or minimum current phase is controlled according to the detected current value to protect against a possible short-circuit across the DC capacitor. When the voltage of the DC capacitor exceeds a preset value, the voltage is suppressed by operating active or passive power devices.

An electrical generator includes a stator having fractional-slot concentrated windings and a rotor having field windings. A drive is provided having a circuit to control current flow to the field windings and a controller to input an initial DC field current demand to the circuit to cause the circuit to output an initial DC field current representative of a DC field current demand that would cause an electrical generator having sinusoidal stator windings to output a desired AC power. The controller receives feedback on the magnetic field generated by the initial DC field current, isolates an ideal fundamental component of the magnetic field based on the feedback and to generate a modified DC field current demand, and inputs the modified DC field current demand to the circuit, thereby causing the circuit to output an instantaneous non-sinusoidal current to the field windings to generate a sinusoidal rotating air gap magnetic field.

A wind power generator generates power through a rotation of a rotor and is interconnected, and operated with its power generation output previously limited in order to be able to further supply the power to a power system in response to a decrease in system frequency. Thus, a concentrated control system derives a required restricted amount corresponding to a power generation output required to respond to the decrease in system frequency, derives a value by subtracting an amount corresponding to a latent power generation output with which the power generation output can be increased, from the required restricted amount, and sets a restricted amount of the power generation output in each wind power generator to perform the operation with the power generation output previously limited to respond to the decrease in system frequency, based on the above value.

A fault tolerant electrical machine including: a plurality of phases; a detector arranged to detect a fault in at least one of the phases; and a controller arranged to intentionally cause a fault in at least one other of the phases such that the vector sum of the second harmonic power vectors of the remaining phases is zero.

A generator system includes a generator having a stationary portion and a rotating portion. The generator includes a permanent magnet based exciter with permanent magnets disposed on the stationary portion. A first channel includes a first main field winding and a first main field power converter disposed on a rotating portion. The first main field power converter selectively delivers voltage from the exciter winding to the first main field winding. A second channel includes a second main field winding and a second main field power converter disposed on the rotating portion. The second main field power converter selectively delivers voltage from the exciter winding to the second main field winding. A generator control unit is connected to the first channel and the second channel. The generator control unit monitors an output voltage at each of the first channel and the second channel and generates the first and second control signals based on the output voltage.

An inverter generator used in combination with a motor and an ECU generating a pulse at each predetermined rotation angle of the motor is comprised of: an electric generator driven by the motor configured to generate alternating current electric power; estimating means for estimating an electrical angle of alternating voltage of the alternating current electric power from the pulse, the estimating means being electrically connected with the ECU; a converter configured to convert the alternating current electric power into direct current electric power, the converter electrically connected with the electric generator and the estimating means; and an inverter configured to convert the direct current electric power into alternating current output electric power, the inverter electrically connected with the converter.

The control system of this floating wind turbine generator is a control system of a floating wind turbine generator in which the control system controls a pitch angle control section by a pitch angle instruction value calculated on the basis of signals detected by a second sensor detecting a relative angle between a nacelle and a tower and a third sensor detecting a yaw angle from a reference position of the tower so that a signal detected by a first sensor detecting wind direction deviation relative to a vertical direction of a rotation plane of wind turbine blades indicates an angle within a predetermined range from the vertical direction of the rotation plane of the wind turbine blades, and controls a yaw driving device by a yaw driving instruction value calculated on the basis of the signals detected by the second sensor and the third sensor.

A DC chopper comprising a control unit and a power circuit and a DC chopping method for a DFIG (doubly fed induction generator) system are provided. The input terminal of the control unit is coupled to a DC capacitor of a converter to detect a DC voltage. The power circuit includes input terminals, an overvoltage protection module, a rectifier module and output terminals. The overvoltage protection module comprises at least one discharge unit formed from a discharge resistor and a switch element, and the rectifier module is coupled in parallel to the overvoltage protection module. When a grid voltage drops, the control unit outputs a corresponding control signal to drive the switch element to be ON or OFF, and the output terminal of the power circuit absorbs a portion of rotor inrush current, so as to impose over-current protection.

An electric power generation system (EPGS) employs both a wild-source generator and a variable and/or constant frequency generator. The wild-source generator is coupled to receive mechanical power from a low-pressure spool on an aircraft engine and to generate in response a wild-source output for consumption by voltage and frequency-tolerant loads. The variable and/or constant frequency generator is coupled to receive mechanical power from a high-pressure spool on the aircraft engine and to generate in response a variable and/or constant frequency output for consumption by voltage and frequency-intolerant loads.

An integrated power system suitable for simultaneously powering marine propulsion and service loads. The system includes: (a) at least one generator configured with at least first and second armature windings configured to output respective first and second alternating current power signals of different voltages, the at least two armature windings positioned within the same stator slots so that they magnetically couple; (b) at least first and second rectifier circuits coupled to said generator to convert said first and second alternating current power signals into first and second direct current power signals; and (c) a first load to which said first direct current power signal is coupled and a second load to which said second direct current power signal is coupled.

An electrical machine includes a stator having a main armature winding, an exciter field winding, and a transformer primary winding. A rotor is operatively connected to rotate relative to the stator, wherein the rotor includes an exciter armature winding operatively connected to the exciter armature winding for field excitation therebetween, a main field winding operatively connected to the main armature winding for field excitation therebetween, and a transformer secondary winding operatively connected to the transformer primary winding to form a rotating transformer. A generator control unit is operatively connected to the main armature winding, exciter field winding, and transformer primary winding to control the main armature and exciter field windings based on excitation in the primary winding received from the transformer secondary winding.

A method for converting heat to electric energy is described which involves thermally cycling an electrically polarizable material sandwiched between electrodes. The material is heated by extracting thermal energy from a gas to condense the gas into a liquid and transferring the thermal energy to the electrically polarizable material. An apparatus is also described which includes an electrically polarizable material sandwiched between electrodes and a heat exchanger for heating the material in thermal communication with a heat source, wherein the heat source is a condenser. An apparatus is also described which comprises a chamber, one or more conduits inside the chamber for conveying a cooling fluid and an electrically polarizable material sandwiched between electrodes on an outer surface of the conduit. A gas introduced into the chamber condenses on the conduits and thermal energy is thereby transferred from the gas to the electrically polarizable material.

A magnetic controlled power generator provides a magnetic controlled loading device, power generator and flywheel device to form two independent modules which are easily assembled and disassembled for easy manufacture and maintenance. Besides, the magnetic controlled power generator has simple installation and lightweight components to generate a radial displacement for magnetic flux control, achieving continuous adjustment of the load resistance, thereby having the effect of reducing the cost and weight.

Some embodiments relate to a method of controlling speed of a variable speed generator. The method includes detecting a load of the variable speed generator and determining a target speed for the variable speed generator based on the load supplied by the variable speed generator. The method further includes using a controller to adjust the speed of the variable speed generator based on the target speed. The method may further include correcting the target speed by calculating a correction factor that corrects the target speed based on a voltage produced by the variable speed generator.

Systems and methods for monitoring excitation of a generator based on a faulty status of a generator breaker are provided. According to one embodiment, a system may include a controller and a processor communicatively coupled to the controller. The processor may be configured to receive, from a contact associated with a generator breaker, a reported status of the generator breaker, receive operational data associated with one or more parameters of a generator associated with the generator breaker, and correlate the reported status of the generator breaker and the operational data. Based on the correlation, the processor may establish an actual status of the generator breaker, and, based on the actual status, selectively modify a mode of excitation of the generator.

A temperature detection device that detects a temperature of a rotor of a motor. The temperature detection device has a current detection unit configured to detect a current value of a current flowing through a winding with which any one of a stator and the rotor of the motor is provided, an iron loss estimation unit configured to estimate an iron loss of the rotor using the current value, and a rotor temperature estimation unit configured to estimate the temperature of the rotor using the iron loss.

According to an embodiment, a method of operating a wind turbine comprising a DC-to-AC voltage converter is provided, the wind turbine being connectable to a grid via the DC-to-AC voltage converter, the method comprising: determining a line voltage of a power line connecting the DC-to-AC voltage converter to the grid; if the determined line voltage exceeds a predefined voltage threshold value, injecting reactive current into the power line, wherein the amount of reactive current injected is chosen such that an output voltage of the DC-to-AC voltage converter is kept within a predetermined voltage range.

A generator includes a permanent magnet generator, an exciter and a main generator mounted for rotation on a shaft. The main generator is configured to produce a voltage output. A generator control unit includes a circuit configured to provide current from the permanent magnet generator to the exciter. A switch is provided in the circuit and is configured to change between open and closed conditions. The switch is configured to flow current in the circuit in the closed condition and interrupt current flow in the open condition. An overvoltage limit controller is programmed to determine an amount of overvoltage of the output voltage exceeding a desired voltage. Either a fixed reference threshold is used or a reference threshold voltage is calculated based upon the duration in over voltage condition, and the switch is modulated between the open and closed conditions according to error between the actual output voltage and the reference threshold voltage to limit the output voltage to the desired reference threshold voltage.

A method of controlling a generator (110) of an electric drive (104) associated with an engine (102) is provided. The method may determine an operational state of the electric drive (104) based on a speed of the engine (102), and selectively engage one of a map-lookup control scheme (150) and a fixed-theta off control scheme (152) for operating the generator (110) based on the operational state of the electric drive (104).

A power supply system for a motor vehicle includes a generator that includes a rotor having a field coil and a stator having an armature coil; a rectifier that rectifies AC power generated in the armature coil; an excitation control circuit that takes control of a voltage applied to the field coil; a capacitor that is connected to the DC side of the rectifier, and receives and transfers the rectified power; a battery connected to an electric load of the motor vehicle; a DC-DC converter that is connected between the capacitor and the battery and capable of converting unidirectionally or bidirectionally an input DC voltage into any DC voltage; and a selection switch which connects the capacitor or the battery to the excitation control circuit as a power supply source.

A method for converting heat to electric energy is described which involves thermally cycling an electrically polarizable material sandwiched between electrodes. The material is heated using thermal energy obtained from: a combustion reaction; solar energy; a nuclear reaction; ocean water; geothermal energy; or thermal energy recovered from an industrial process. An apparatus is also described which includes an electrically polarizable material sandwiched between electrodes and a heat exchanger for heating the material. The heat source used to heat the material can be: a combustion apparatus; a solar thermal collector; or a component of a furnace exhaust device. Alternatively, the heat exchanger can be a device for extracting thermal energy from the earth, the sun, ocean water, an industrial process, a combustion reaction or a nuclear reaction. A vehicle is also described which comprises an apparatus for converting heat to electrical energy connected to an electric motor.

A thermionic generator for converting thermal energy to electric energy includes: an emitter electrode for emitting thermal electrons from a thermal electron emitting surface when heat is applied to the emitter electrode; a collector electrode facing the emitter electrode spaced apart from the emitter electrode by a predetermined distance, and receiving the thermal electrons from the emitter electrode via a facing surface of the collector electrode; and a substrate having one surface. The emitter electrode and the collector electrode are disposed on the one surface of the substrate, and are electrically insulated from each other. The thermal electron emitting surface and the facing surface are perpendicular to the one surface.

A method of operating a converter of a wind turbine for providing electric energy to a utility grid includes determining a grid voltage. If the grid voltage is between a nominal voltage and a first voltage threshold, i.e. higher than the nominal voltage, a normal procedure for lowering the grid voltage is performed. If the grid voltage is above the first voltage threshold, another procedure for keeping the wind turbine connected is performed, wherein the other procedure is different from the normal procedure. Further a corresponding arrangement is described.

An AC current generator for generating an CA current and method therefor and includes a stator and a rotor. The stator includes an outer shell of non-magnetic material enclosing an evacuated chamber and having a distribution of a plurality of ferromagnets attached thereto. The rotor includes an inner core of non-magnetic material located at a stability location within said evacuated chamber and having a distribution of a plurality of diamagnets attached thereto. In addition, the AC current generator includes at least one magnetic flux detection unit located within at least one magnetic field generated by at least one group of ferromagnets of the plurality of ferromagnets. Displacing the rotor from the stability location towards the at least one group of ferromagnets generates a change in magnetic flux in the magnetic field thereby generating an AC current in the at least one magnetic flux detection unit.

Wind turbine systems and methods are provided. An exemplary system includes a wind driven doubly fed induction generator having a rotor and a stator, the stator providing AC power to a stator bus. The system further includes a power converter coupled to the rotor of the doubly fed induction generator, the power converter providing an output to a line bus, and a transformer coupled to the stator bus. The system further includes a solid-state switch coupled between the stator bus and the transformer.

A generator drive system for the generator (3) of an internal combustion engine (1), including a flexible drive having a traction mechanism (5) which is guided across a generator pulley (6) driving the generator (3). The generator (3) is configured and electrically wired such that the generator (3) can be temporarily driven as a motor, and the generator (3) is coupled to the generator pulley (6) or the crankshaft pulley (7) is coupled to the crankshaft (8) via an overrunning clutch (4) which allows the generator (3), when operated as a motor, running faster than the generator pulley (6) or, taking into consideration a gear ratio, the crankshaft (8).

Systems and methods for reducing current imbalance between parallel bridge circuits used in a power converter of a doubly fed induction generator (DFIG) system are provided. A control system can monitor the bridge current of each of the bridge circuits coupled in parallel and generate a feedback signal indicative of the difference in bridge current between the parallel bridge circuits. Command signals for controlling the bridge circuits can then be developed based on the feedback signal to reduce current imbalance between the bridge circuits. For instance, the pulse width modulation of switching devices (e.g. IGBTs) used in the bridge circuits can be modified to reduce current imbalance between the parallel bridge circuits.

A method is employed for operating a wind turbine. Electrical energy is produced by means of a generator and is fed into an electrical power network. The electrical energy is fed to the secondary side of a transformer at a low voltage and is output on the primary side of the transformer at a higher voltage. The potential on the primary side of the transformer is undefined. In the method, a measured value of the voltage between the primary side of the transformer and the earth potential is first recorded. The measured value is compared with a predefined limit value. The electrical energy produced by the generator is changed if the measured value exceeds the limit value. A wind turbine is designed to carry out the method. Faults in the medium voltage network can be reacted to without an additional star point on the primary side of the transformer being required.