Abstract: The present invention is directed to a compensator-filter circuit for reducing low order current harmonics in a three-phase drive system driving a single-phase load, the three-phase drive system including a three-phase source voltage connected to a rectifier system connected to a DC link capacitor connected to a three-phase voltage source inverter.

Abstract: The present invention relates to a three-phase inverter (1) with a circuit arrangement having a DC-voltage input (2) for at least one direct voltage source, and a three-phase alternating voltage output (15) for feeding into a three-phase alternating voltage mains (19), wherein said inverter comprises a three-phase bridge circuit (20) as well as at least one divided intermediate circuit, wherein said inverter (1) is configured to be transformerless, wherein said neutral conductor (N) of the mains (19) is separated from the central point (M) of the intermediate circuit and the inverter (1) is connected to the alternating voltage mains (19) via a three-conductor connection (15).

Abstract: A method is disclosed for the operation of a converter circuit, wherein the converter circuit has a converter unit having a multiplicity of actuatable power semiconductor switches and an LCL filter which is connected to each phase connection of the converter unit, in which the actuatable power semiconductor switches are actuated by means of an actuation signal (S) formed from a hysteresis active power value (dP), from a hysteresis reactive power value (dQ) and from a selected flux sector (?n). The hysteresis active power value (dP) is formed from a differential active power value (Pdiff). In addition, the hysteresis reactive power value (dQ) is formed from a differential reactive power value (Qdiff). An apparatus for carrying out the method is also disclosed.

Abstract: Systems and methods disclosed herein monitor and control input to a converter in one or more of a UPS, a frequency converter, or a line conditioner. Distortion due at least in part to ripple voltage can be removed from a control signal that controls input current to the converter. The systems and methods described herein afford a simple and effective way to reduce or eliminate one or more of subharmonic oscillation and total harmonic distortion from a converter input current during synchronous and asynchronous modes of operation. The converter may include one or more of a rectifier and an inverter.

Abstract: In order to improve reliability, cost performance, and cooling property, a control device integrated dynamo-electric machine mounted to a dynamo-electric machine includes an inverter bridge configured with a plurality of semiconductor switching elements, and a plurality of heat sinks provided for respective arms of the inverter bridge and having the semiconductor switching elements of the corresponding arms mounted thereon for cooling the mounted semiconductor switching elements, wherein the semiconductor switching element includes a plurality of semiconductor switching devices arranged in parallel, and the plurality of semiconductor switching devices arranged in parallel are mounted on the common heat sinks.

Abstract: An electric power converter circuit includes a rectifying circuit having diodes, a coil, and a full-bridge circuit including switching devices, which are connected in cascade to an AC power supply 1, to convert an AC to a DC and to further convert the concerted DC to an AC. The converter circuit further includes a series circuit having a capacitor and a switching device, and connected between the DC terminals of the full-bridge circuit. One of the switching devices on the upper arm and one of the switching devices on the lower arm are turned simultaneously ON for a certain period of time. The electric power converter circuit facilitates reducing the number of the constituent parts, size, weight and manufacturing costs thereof.

Abstract: There is described a method for controlling a quenching device for a converter bridge with line regeneration, whereby the converter bridge controlled by a network-timed control circuit by ignition pulses is connected with its three inputs to the phases of a three-phase network and the two outputs of the bridge are connected to a direct-current motor which feeds, when operated as a generator, current back to the three-phase network via the bridge. The quenching device is controlled by a trigger unit which emits trigger pulses depending on the monitoring of electrical and temporary variables. The quenching device comprises, for each bridge half, a quenching condenser that can be charged by a charging circuit quenching voltage. The quenching condensers, in the event of quenching, can be connected to the bridge halves by means of switches that are controlled by the trigger unit.

Abstract: An active filter for reducing the common mode current in a pulse width modulated drive circuit driving a load, said drive circuit comprising an a-c source, a rectifier connected to said a-c source and producing a rectified output voltage connected to a positive d-c bus and a negative d-c bus, a PWM inverter having input terminals coupled to said positive d-c bus and negative d-c bus and having a controlled a-c output, a load driven by said a-c output of said PWM inverter, a ground wire extending from said load, and a current sensor for measuring the common mode current in said drive circuit, said current sensor producing an output current related to said common mode current; said active filter comprising a first and second transistor, each having first and second main electrodes and a control electrode, and an amplifier circuit driving said transistors; said first electrode of said first and second transistor coupled to a common node, said second electrodes of said first and second transistors being coupled t

Abstract: An electrical system for a vehicle includes a power source providing electrical power to a first and a second electrical motor. Each motor has two or more windings, and each winding has a first end and a second end. A boost link such as a battery or capacitor is configured to store electrical energy for subsequent retrieval and use by either electrical motor. A first inverter circuit includes a first grouping of switches, wherein each of the first group of switches couples one of the first ends of the windings to the power source. A second inverter circuit includes a second group of switches, each coupling one of the second ends of the windings to the boost link. A controller is coupled to activate each of the first and second groups of switches to thereby allow the electrical energy to be placed on and retrieved from the boost link.

Abstract: A current sensor for detecting a power supply current is commonly used for detecting a current of a stator winding to detect a rotational position of a magnet rotor, so that a sinusoidal driving is realized without adding two current sensors for detection of a phase current, and also a phase shift circuit and a comparator needed in the conventional 120-degree current feeding are not required, and the number of components can be reduced. Therefore, an inverter device with a low noise and low vibration, having a small size, light weight and high reliability is obtained.

Abstract: Techniques are disclosed to regulate a power supply with a compensation signal generation circuit. One example regulated power supply includes a sense circuit coupled to sense an output voltage of the regulated power supply. The regulated power supply also includes a switching power converter circuit, which includes a switch coupled to be switched in response to a control signal received from the sense circuit to regulate the output voltage of the regulated power supply. The regulated power supply also includes a compensation signal generation circuit coupled to receive a switching signal representative of a switching of the switch in the switching power converter circuit. The compensation signal generation circuit is to generate a compensation signal to approximate a load current to be delivered from an output of the regulated power supply. The compensation signal is to be received by the sense circuit to modify the control signal.

Abstract: A problem to be solved by the present invention is to eliminate variation in potential in a turn-off time period of each GTO element, and to stabilize a gate drawing current by surely performing the turn-off of the GTO element. In an inverter apparatus having a three-phase inverter configured to include paired GTO elements an inverter control portion has a simultaneous switching prevention function of delaying a turn-on operation of each of the GTO elements which correspond to phases other than a phase corresponding to an optional one of the GTO elements and also correspond to an electrode opposite to an electrode corresponding to the optional one of the GTO elements by a predetermined time in a case where a turn-on command signal for turning on each of the GTO elements is generated within a predetermined time period since the turn-off of the optional one of the GTO elements.

Abstract: The power switches of an inverter are mechanically integrated with an electric motor of a vehicle and are mounted on the end plate of the motor and employ short connections between the motor a-c terminals and the inverter a-c output terminals. Bond wireless modules are employed. The electronic controls for the inverter are mounted on a main control board which is positioned remotely from the inverter and is not subject to the heat and EMI produced by the inverter.

Abstract: An apparatus and method for converting DC voltage across positive and negative DC buses to three phase AC voltages on first, second and third AC output lines, the method comprising the steps of providing first and second three phase inverters that include a first subset of inverter switches and a second subset of inverter switches, respectively, linking a first choke in series with the first three phase inverter between the positive and negative DC buses and the AC output lines, linking a second choke in series with the second three phase inverter between the positive and negative DC buses and the AC output lines and synchronously controlling the first and second inverter switch subsets so that switching of first and second inverter switch subsets is substantially synchronized among the three phases.

Abstract: A power inverter comprises a power module connected at least to a rotating electric machine, a gate drive circuit board which supplies switching power to the power module, and a rotating electric machine control circuit board which supplies a signal for controlling the waveform of the switching power to the gate drive circuit board. A noise reduction board is formed on a board different from the rotating electric machine control circuit board. The configuration of the noise reduction board is such that various signals for forming a signal for controlling the waveform of the switching power by means of the rotating electric machine control circuit board are inputted through the noise reduction board to the rotating electric machine control circuit board.

Abstract: In a power converter apparatus, such as an uninterruptible power supply, a phase reference signal is generated responsive to a DC voltage on a DC bus. A magnitude reference signal may be generated responsive to a phase current of an AC bus and/or the DC voltage on the DC bus. Power is transferred between the AC and DC busses responsive to the phase reference signal and the magnitude reference signal. Generation of the phase reference signal may include generating a DC voltage error signal responsive to the DC voltage on the DC bus, generating a phase offset signal responsive to the DC voltage error signal, and generating the phase reference signal responsive to the phase offset signal. Generation of the magnitude reference signal may include generating a volt-amperes reactive (VAR) error signal responsive to the phase current and generating the magnitude reference signal responsive to the VAR error signal.

Abstract: A power supply device comprises: a voltage converting portion that converts a voltage generated from a power supply portion into an output voltage to be supplied to a load; a voltage divider circuit that generates an output voltage setting signal for providing a set value of the output voltage; a set value changeover portion that turns on/off set value changeover switches to change a voltage divider ratio of the voltage divider circuit to change the set value; a storage device that stores a state appropriate for each set value changeover switch for keeping the value of the output voltage within a specified range; a set value changeover switch control portion that controls the set value changeover switches so as to bring each set value changeover switch into a state as stored in the storage device when the voltage is supplied from the voltage converting portion to the load; and an output voltage control portion that controls the voltage converting portion so as to make zero a deviation between the value of the

Abstract: A driving circuit for providing a control signal to a power semiconductor device for providing power to a filament lamp, said driving circuit comprising an oscillator for generating said control signal. The driving circuit may further comprise a soft start circuit which controls said oscillator so as to avoid excessive current in said lamp at start-up; a voltage compensation circuit which controls said oscillator so as to compensate for variations in load; a shutdown circuit for shutting down and automatically restarting said oscillator in response to a fault condition; an adaptive dead time circuit which controls said oscillator for providing cool running of said power semiconductor device; and/or a dimming circuit which controls said oscillator for driving said lamp. The driving circuit and its control circuitry may be implemented in an integrated circuit.

Abstract: A control system for a PWM inverter may reduce a DC component of an output of the inverter. An output voltage signal may be attenuated with a low-pass filter to produce a signal with a high DC content. A duty cycle of an output of the low pass filter may be determined with a zero-crossing detector. A calculation may be performed to determine a magnitude of a DC offsetting voltage that may offset the DC component of the inverter output. The inverter may be commanded to produce a DC offsetting voltage with an opposite polarity from the DC component of the inverter output. The opposite polarity DC offsetting voltage may effectively cancel the DC component of the inverter output. A monitoring system may employ an alternate system for determining the level of the DC component, thus providing a desirable redundancy to the system.

Abstract: A backlight inverter is provided which includes at least one inverter transformer and to which a plurality of cold cathode fluorescent lamps are connected, wherein a plurality of primary windings of the inverter transformer are connected to each other either in series or in parallel, a resonance circuit including a leakage inductance and a capacitance component is formed at the secondary side of the inverter transformer, and wherein the inverter transformer is driven at an operating frequency which is included in a frequency range between a parallel resonance frequency and a series resonance frequency of the resonance circuit and which excludes a frequency range between a first inflection point and a second inflection point of a gain characteristic curve of the inverter transformer.

Abstract: By reduction in loss and noise of a three-phase reactor on the AC side of an electric power converter, compactness and reduction in weight of the reactor are realized, and countermeasures for heat and noise are reduced, and a specific frequency component is reduced, thus cost reduction and conversion efficiency are improved, and carriers of a controller are prepared in correspondence to the phases of the electric power converter, and moreover a phase difference of each carrier is set properly.

Abstract: A common mode noise cancellation circuit eliminates common mode noise generated by a high-frequency switching device. The common mode noise reduction circuit includes a single switching device and a transformer. The switching device receives a rectified voltage and produces a switched voltage. The transformer includes a first primary winding, a second primary winding, and a secondary winding. The transformer couples the switched output from the first and the second primary winding to the secondary winding to generate a transformed voltage. A positive signed common mode noise waveform generated by the switching device is coupled from the first primary winding to the first secondary winding, and a negative signed common mode noise waveform generated by the switching device is coupled from the second primary winding to the first secondary winding, which results in a lower magnitude common mode noise waveform being present at the secondary winding.

Abstract: A method for operating a converter circuit is specified with the converter circuit having a converter unit with a multiplicity of controllable power semiconductor switches and having an energy storage circuit formed by two series-connected capacitors, in which the controllable power semiconductor switches are controlled by means of a control signal formed from a hysteresis signal vector (x), and the hysteresis signal vector (x) is formed from a difference-phase connection current vector (?ifi,i) by means of a hysteresis regulator, and the difference-phase connection current vector (?ifi,i) is formed from the subtraction of a phase connection current vector (ifi,i) from a reference phase connection current vector (ifi,i,ref), with the reference phase connection current vector (ifi,i,ref) being formed from a difference power value (Pdiff), a difference wattless-component value (Qdiff) and a phase flux vector (?g,??).

Abstract: This present invention relates to a paralleled power conditioning system with circulating current filter, comprising: an input terminal for receiving a input power; a plurality of power conditioning units; and a load. Each power conditioning unit includes: a DC/DC converter coupled to the input for receiving the input power so as to convert the input power to a DC voltage; a DC/AC inverter coupled to the DC/DC converter for converting the DC voltage to a AC voltage; and a filter coupled to the DC/AC inverter for eliminating the noise generated by the AC voltage and the circulating current among the plurality of power conditioning units so as to generate a filter voltage. The load is connected to the plurality of power conditioning units. The plurality of power conditioning units are connected in parallel to the load.

Abstract: A filter assembly is provided which includes a Faraday cage interface. Electrical noise is filtered by the Faraday cage interface. The Faraday cage interface is configured to prevent passage of electromagnetic waves.

Abstract: A method is provided for minimizing a double-frequency ripple power exchanged between a load and an energy source, the energy source delivering electrical power to the load through a single-phase power conditioner, and the power conditioner being coupled to an energy storage device. The method senses a first AC waveform at the output of the power conditioner, generates a second AC waveform at the energy storage device, the second AC waveform having the same frequency as the first AC waveform, and shifts the second AC waveform by a phase shift equal to ?/4 radians relative to a phase of the first AC waveform, thereby minimizing the double-frequency ripple power in the power supplied by the energy source.

Abstract: An auxiliary circuit for reducing low order current harmonics in a three-phase drive system driving a single-phase load, the three-phase drive system including a three-phase source voltage connected to a rectifier system connected to a DC link choke inductor connected to a three-phase current source inverter system.

Abstract: A stabilized power supply for X-ray tubes having a first rectifier circuit, an inverter circuit comprising main switches, a transformer, a second rectifier circuit an oscillation circuit and an inverter circuit. The power supply includes an auxiliary circuit that can be driven and is parallel-connected to the oscillation circuit. The auxiliary circuit duplicates changeover switching times of the switches of the inverter in order to limit an overlapping phenomenon that occurs for these switches during the changeover switching operations.

Abstract: A method for regulating a voltage using a linear voltage regulator is provided. The linear voltage regulator has a first circuit with a primary output node and a second circuit having first and second inverters electrically coupled to the primary output node. The method includes receiving a first voltage from a voltage source at the first circuit. The method further includes removing frequency components of the first voltage in a first frequency range to obtain an output voltage at the primary output node utilizing the first circuit. The method further includes removing frequency components of the output voltage in a second frequency range utilizing the first and second inverters of the second circuit, the second frequency range being greater than the first frequency range.

Abstract: A linear voltage regulator is provided. The linear voltage regulator includes a first circuit configured to receive the first voltage from a voltage source and to remove frequency components of the first voltage in a first frequency range to obtain an output voltage at a primary output node. The linear voltage regulator further includes a second circuit having first and second inverters electrically coupled to the primary output node of the first circuit. The second circuit is configured to receive the output voltage and to remove frequency components of the output voltage in a second frequency range. The second frequency range is greater than the first frequency range.

Abstract: Three-level inverter and rectifier power conversion systems and space vector modulation (SVM) controls having even-order harmonic elimination for neutral voltage balancing with a predefined vector switching sequences for half-wave symmetry in open loop system operation. The vector sequence listings for each SVM diagram segment includes switching state entries individually indicating one of three possible switching state levels positive (P), zero (0), or negative (N) for each of three or more switching groups of the power conversion system, with listings for each pair of first and second diametrically opposite diagram segments include symmetrically opposite switching states, with positive levels in the entries of the listing for the first segment corresponding to negative levels in the entries of the listing for the second segment and vice versa.

Abstract: A coordination control device of a power output apparatus includes a coordination control unit. The coordination control unit calculates an intermediate value between the maximum value and minimum value among voltage controls for a first motor generator, and voltage control from an AC voltage control generation unit to generate an AC voltage across neutral points of first and second motor generators, and outputs a value that is each phase voltage control for the first and second motor generators minus the calculated intermediate value to a signal generation unit as the final voltage control for the first and second motor generators.

Abstract: The present invention provides a modulation controller for use with a three phase converter. In one embodiment, the modulation controller includes a three phase modulator configured to provide vector control signals for the three phase converter that generate a common mode voltage. Additionally, the modulation controller also includes a transition modifier coupled to the three phase modulator and configured to provide a shaping function for the vector control signals that extends a transition period of the common mode voltage.

Abstract: A control circuit having frequency modulation is used for reducing the EMI of a power converter. A switching circuit is couple to a feedback circuit to generate a switching signal for regulating an output of the power converter. A first oscillator is equipped to determine a switching frequency of the switching signal. A second oscillator is coupled to the first oscillator to modulate the switching frequency of the switching signal for reduce the EMI of the power converter. A programmable resistor is designed to attenuate the feedback signal of the feedback circuit. The resistance of the programmable resistor is controlled by the output of the second oscillator. Therefore, the output power and the output voltage can be kept constant when the switching frequency is modulated.

Abstract: A compensator circuit for reducing low order current harmonics in a three-phase drive system driving a single-phase load, the three-phase drive system including a three-phase source voltage connected to a rectifier system connected to a DC link capacitor connected to a three-phase voltage source inverter that supplies three-phase power.

Abstract: An apparatus to convert a direct current to an alternating current includes a power module disposed between an input terminal of the direct current and output terminal of the alternating current, the power module comprising an on/off switch element, a first smoothing condenser connected in parallel with the power module, a second smoothing condenser connected in parallel with the power module, the second smoothing condenser comprising an electrostatic capacity less than the first smoothing condenser, a first wiring connecting the power module and the first smoothing condenser, and a second wiring connecting the power module and the second smoothing condenser, the second wiring comprising an inductance greater than the first wiring.

Abstract: A system and method for precharging a harmonic filter connected to a power supply line to receive AC power and deliver the AC power to the motor drive unit includes a control circuit. The control circuit is configured to monitor an operational state of the motor drive unit or the power supply line, and generate a first control signal upon a predetermined change in the operational state and a second control signal delayed from the first control signal. The system also includes a charging circuit having a first switch configured to actuate in response to the first control signal to provide a reduced power to at least a portion of the harmonic filter and a second switch configured to actuate in response to the second control signal to provide a non-reduced power to the at least a portion of the harmonic filter.

Abstract: A topology for a three-phase, wye-connected H-bridge converter allowing continued operation when one H-bridge phase has failed by bypassing the failed H-bridge, increasing dc-bus voltage to provide the required output load voltage, and decreasing switching frequency to reduce power losses in semiconductor switches. In normal operation, the dc-bus voltage is operated at a lower voltage, improving the reliability of power semiconductor devices. When an H-bridge is bypassed, the dc-bus is operated at a higher voltage but lower effective switching frequency, reducing semiconductor losses, allowing the converter to put out more current with the same temperature rise in the power switches.

Abstract: Apparatus, systems, and methods are provided for reducing voltage source inverter losses. One apparatus includes a sensor couplable to the motor and configured to sense an operating frequency of the motor and an amount of torque produced by the motor. The apparatus also includes a controller coupled to the sensor, the controller configured to determine a zero vector modulation (ZVM) based on the sensed frequency and torque. A system includes means for sensing a threshold output frequency of the motor and means for sensing a threshold torque of the motor. The system also includes means for determining a ZVM for the inverter based on the sensed threshold frequency and threshold torque. One method includes sensing that a motor is operating below a threshold frequency and is producing torque above a threshold torque amount. The method also includes determining a ZVM for the inverter based on the sensed frequency and torque.

Abstract: A solid state reversing AC motor starter that employs a DC power source and a power bridge employing insulated gate bipolar transistors that provide an ungrounded three phase AC output. The AC output is connected to the power input of the motor starter, which requires simultaneous RUN and Directional Commands to initiate valve actuation.

Abstract: A photovoltaic system, method and apparatus are disclosed. In an exemplary embodiment, the system includes a photovoltaic array, a distribution system that distributes power within a premises of a demand-side energy consumer, an inverter coupled to the distribution system that is configured to convert DC power from the photovoltaic array to AC power and apply the AC power to the distribution system, a damping portion configured to damp high frequency voltages derived from the inverter, and trapping circuitry coupled to the damping portion that is configured to reduce a level of low frequency current traveling through the damping portion.

Abstract: A method is disclosed for operating a converter circuit, with the converter circuit having a converter unit with a plurality of drivable power semiconductor switches and an LCL filter connected to each phase connection of the converter unit, in which the drivable power semiconductor switches are driven by means of a drive signal which is formed from a hysteresis power value, from a hysteresis wattless-component value and from a selected flux sector. An apparatus for carrying out the method is also disclosed.

Abstract: There is described a method for controlling a quenching device for a converter bridge with line regeneration, whereby the converter bridge controlled by a network-timed control circuit by ignition pulses is connected with its three inputs to the phases of a three-phase network and the two outputs of the bridge are connected to a direct-current motor which feeds, when operated as a generator, current back to the three-phase network via the bridge. The quenching device is controlled by a trigger unit which emits trigger pulses depending on the monitoring of electrical and temporary variables. The device has measuring values “direct output current” and/or “supply voltages” used to determine characteristic values which are compared with theoretical characteristic values. Depending on the result of said comparison, the quenching device is optionally activated.

Abstract: An exciter system for the field of a synchronous generator excitation is provided. The exciter system includes an AC power source; a three-phase thyristor bridge having six legs, the three-phase bridge being connectable with the AC power source, and being adapted to provide a variable DC voltage output; a thyristor in each of the six legs of the three-phase bridge, wherein the thyristors provide a path for a device current; and a three-phase AC line filter series, including series resistive and capacitive elements across each phase of the AC power source and a plurality of bleed resistors, wherein at least one bleed resistor is connected to each AC input connection of the filter.

Abstract: The invention relates to a supply device (13) which feeds a consumer (7) with power by means of a supply network (12). Said supply device (13) fulfils both the function of a power supply and the function of a network filter, an optimum working point to be adjustable in terms of the operating modes as supplier/active filter, according to the required energy reserves. This is achieved by means of an active phase effect filter, a harmonic wave detection means (3) determining a compensating power dependent on the network harmonic wave power, and a control device component (5) whose action is adapted to the compensating power requirement being provided for the determination of an amplification factor (6). The compensating power is supplied to the current inverter according to the utilisation of the current inverter (1) and the amplification factor (6).

Abstract: An active power filter comprises an energy storage capacitor, an inverter, a filtering circuit and a controller. The inverter is controlled to act as a virtual resister at a fundamental frequency for compensating for the power loss of the active power filter, act as a virtual capacitor at a fundamental frequency for compensating for a fundamental reactive power of the load, and/or generate a harmonic current for suppressing the harmonic currents of specific orders of the load.

Abstract: A rotating machinery includes a first control member for performing rectangular wave control by operating the switching devices of an inverter such that an on-state and an off-state occur once for one cycle period in electrical angle of a motor, a second control member for operating the switching devices on the basis of a magnitude relation between upper and lower limits of a predetermined hysteresis region and an actual current flowing through the motor, and a switching member for, when the actual current deviates from the hysteresis region while the rectangular wave control is undertaken, switching the control to an instantaneous current value control performed by the second control member.

Abstract: A method of designing a random pulse width modulation (RPWM) inverter with unwanted harmonic elimination, which first uses a Fourier analysis and a numerical analysis to eliminate the unwanted harmonic components, next uses the equal area approach to produce switching angles to be used as start values for solving non-linear equations, next selects low-order harmonics to be eliminated and randomly sampled harmonics to solve the equations and obtain pluralities of switching angles for eliminating different harmonics, next applies pluralities of harmonics to a random probability function to thereby obtain a harmonic distribution, and finally uses a random sampling to evenly disperse the higher side-band harmonic components and effectively suppress the low-order harmonic components.

Abstract: A method and an arrangement for controlling an inverter provided with a voltage intermediate circuit, the inverter (1) comprising two or more sub-inverters (1A, 1B, 1C), each being connected with a specific cable to feed a common load (2) and each sub-inverter (1A, 1B, 1C) receiving the same switch instruction pattern. The method comprises the steps of determining the magnitude of a time delay, and consecutively generating, with each sub-inverter (1A, 1B, 1C), an output voltage according to the switch instruction for the load (2) such that each sub-inverter generates an output voltage according to the switch instruction after a time equal to the time delay.

Abstract: A new current loop control system method is proposed for a single-phase grid-tie power conditioning system that can be used under a standalone or a grid-tie mode. This type of inverter utilizes an inductor-capacitor-inductor (LCL) filter as the interface in between inverter and the utility grid. The first set of inductor-capacitor (LC) can be used in the standalone mode, and the complete LCL can be used for the grid-tie mode. A new admittance compensation technique is proposed for the controller design to avoid low stability margin while maintaining sufficient gain at the fundamental frequency. The proposed current loop controller system and admittance compensation technique have been simulated and tested. Simulation results indicate that without the admittance path compensation, the current loop controller output duty cycle is largely offset by an undesired admittance path. At the initial simulation cycle, the power flow may be erratically fed back to the inverter causing catastrophic failure.