395 results about "Voltage inverter" patented technology

A static inverter for a battery of elementary, current sources or cells electrically in series and a number N of intermediate voltage taps along the chain of elementary DC current sources, wherein the number of elementary cells comprised between an intermediate tap and another intermediate tap adjacent to it or an end terminal of said chain is proportionate to the amplitude in the respective phase interval of a number N of discretization phases of the waveform of the AC voltage to be output in a quadrant; is implemented by arranging for: a number N of power switches each connecting a respective intermediate tap and a first end terminal of a first polarity of said chain of elementary cells in series to a common circuit node of said first polarity; an output bridge stage constituted by at least four power switches controlled in pairs for switching the current paths through the bridge stage, having a first pair of nodes coupled to said common circuit node of said first plurality and to the other end terminal of polarity opposite to said first polarity of said chain of elementary cells, respectively, and a second pair of nodes constituting an AC output; and a control circuit sequentially and cyclically turning on, in a continuous manner, one switch at the time of said N switches; each for a phase interval of 1 / (4N) times the period of said AC output, and alternately tuning on by pairs said four power switches of said output bridge stage at every half a period.

A ripple voltage, caused by a voltage inverter, is superimposed on an output voltage provided by a fuel cell stack. This ripple voltage is sensed and used to determine an AC impedance of the fuel cell stack. The determined AC impedance can be correlated to a hydration state of the fuel cell stack.

A current-source sine-wave voltage inverter for converting a direct current (DC) voltage to an alternating (AC) voltage includes a DC source for providing a DC voltage, a current source circuit having a primary side inductance of a transformer, a clamping circuit, an inverting circuit, and a control and driving circuit. The clamping circuit includes a first switch cascaded with a first diode, a second diode cascaded with a second switch, a first capacitor connected between an anode of the first diode and a cathode of the second diode, a secondary side inductance of the transformer cascaded with a third diode, the secondary side inductance of the transformer and the third diode connected to two ends of the DC source, and a cathode of the third diode connected to an anode of the DC source. The present invention also provides a fuel cell system.

According to an aspect of the invention, a motor drive circuit includes a first energy storage device configured to supply electrical energy, a bi-directional DC-to-DC voltage converter coupled to the first energy storage device, a voltage inverter coupled to the bi-directional DC-to-DC voltage converter, and an input device configured to receive electrical energy from an external energy source. The motor drive circuit further includes a coupling system coupled to the input device, to the first energy storage device, and to the bi-directional DC-to-DC voltage converter. The coupling system has a first configuration configured to transfer electrical energy to the first energy storage device via the bi-directional DC-to-DC voltage converter, and has a second configuration configured to transfer electrical energy from the first energy storage device to the voltage inverter via the bi-directional DC-to-DC voltage converter.

A traction inverter circuit includes a first energy storage device configured to output a DC voltage, a first bi-directional DC-to-AC voltage inverter coupled to the first energy storage device, and a first electromechanical device. The first electromechanical device includes a first plurality of conductors coupled to the first bi-directional DC-to-AC voltage inverter, a second plurality of conductors coupled together, and a plurality of windings coupled between the first plurality of conductors and the second plurality of conductors. The traction converter circuit also includes a charge bus comprising a first conductor coupled to the second plurality of conductors of the first electromechanical device, the charge bus configured to transmit a charging current to or receive a charging current from the first electromechanical device to charge the first energy storage device via the first electromechanical device and the first bi-directional DC-to-AC voltage inverter.

An apparatus for transferring energy using onboard power electronics with high-frequency transformer isolation includes a power electronic drive circuit comprises a dc bus and a first energy storage device coupled to the dc bus. A first bi-directional dc-to-ac voltage inverter is coupled to the first energy storage device and to the dc bus, and a first electromechanical device coupled to the first bi-directional dc-to-ac voltage inverter. A charging system coupled to the dc bus via a charge bus comprises a receptacle configured to mate with a connector coupled to a voltage source external to the power electronic drive circuit and an isolation transformer configured to electrically isolate the charge bus from the receptacle. A controller configured to cause the charging system to supply a charging voltage to the dc bus based on a voltage received from the voltage source external to the power electronic drive circuit.

The invention disclose a new positioning method of a distribution network single-phase earth fault, which is applicable to a 3-60 kV neutral point ineffective earth grid. The principle of the positioning method is that: firstly, a high-voltage DC signal is poured into a circuit starting end and the DC signal is detected along the circuit so as to determine a fault area; then a high-voltage AC signal is poured into the circuit starting end, and the AC signal is detected along the circuit so as to determine the position of a fault point. A positioning device developed on the basis of the invention consists of two parts: a high-voltage signal source and a signal detector, wherein, the high-voltage signal source consists of a voltage inverter, a constant flow source, a transformer and a rectifier bridge and is used for pouring a high-voltage DC signal and a high-voltage AC signal; the signal detector comprises a DC detector and an AC detector, wherein, the DC detector consists of a Hall DC detector, a Bluetooth wireless sender and a Bluetooth wireless receiver and is used for measuring the DC signal; while the AC detector consists of an AC electromagnetic field inductor and a signal processing and display segment and is used for measuring the AC signal. The method and the device have mature technique and high reliability.

A single-inductor dual-output buck converter and control method that facilitates power conversion by converting a single DC power source / supply into two separate DC outputs, each of which can be configured to provide a selected / desired voltage by selection of respective duty cycles. The topology of the inverter includes a pair of diodes or switches that can selectively re-circulate inductor current. The converter is generally operated at a fixed frequency with four stages of operation. A first and third stage of operation provide power to a first and second output, respectively. A second and fourth stage of operation re-circulate inductor current and can partially recharge a battery type power source. The power output for each stage (voltage and current) can be selectively obtained by computing and employing appropriate time periods for the stages of operation that correspond to appropriate duty cycles.

The invention discloses a photovoltaic inversion grid-connection and harmonic suppression hybrid system for a micro grid and a composite control method thereof. The photovoltaic inversion grid-connection and harmonic suppression hybrid system for the micro grid comprises photovoltaic array cells, a photovoltaic output filter, a three-phase voltage inverter, an output filter and a passive filter bank. The photovoltaic inversion grid-connection and harmonic suppression hybrid system for the micro grid and the composite control method thereof realize dynamic active and passive power compensation of the micro-grid, stable system voltage, and real-time and dynamic management on harmonic waves.

In an AC link type boosting device, DC terminals of two voltage inverters are connected each other in series in additive polarity and plural AC terminals of each of the voltage inverters are connected to a transformer. The two voltage type inverters are AC linked to each other via the transformer. An external voltage applied between the DC terminals of the AC link type booster is divided by the voltage-type inverters.

This system for converting a direct input voltage into an alternating output voltage comprises two input terminals, two voltage generators connected in series between the input terminals and connected to one another by a middle point, as well as, for each phase of the alternating voltage, an output terminal, two switching branches each connected between the output terminal and a respective input terminal, each switching branch comprising N first switching cells connected in series and N−1 intermediate points, the first switching cells successively being connected to one another by a corresponding intermediate point, N being an integer greater than or equal to 2, and control means for controlling the first switching cells. The system includes, for each phase of the alternating voltage, N−1 pair(s) of capacitors, each pair of capacitors being connected between intermediate points of one of the two switching branches and the other of the two switching branches.

The invention relates to an actuator including an electrical machine. The electrical actuator (100) comprising: a polyphase machine (101); at least one connection member (143) for powering the actuator from at least one network (146) delivering alternating current; and first and second buses (106, 107) connected in parallel between each connection member (143) and the machine (101) for applying frequency control thereto. Each inverter (111, 131) comprises a plurality of arms each having two controlled switches, each phase of the machine (101) being connected both to the two switches of an arm of the first inverter (111) and also to the two switches of an arm of the second inverter (131). The actuator further comprises controlled connection and disconnection means interposed between each bus (106, 107) and each connection member. The invention is applicable to actuators used in aviation.

The invention discloses a bearing-free asynchronous motor RBF neural network self-adaptive inverse decoupling control and parameter identification method. An SVPWM module, a voltage inverter, a bearing-free asynchronous motor and a load of the bearing-free asynchronous motor form a whole serving as a composite controlled object. Two radial basis function neural networks are adopted to achieve inverse control and parameter identification conducted on the composite controlled object. A self-adaptive inverse controller is formed by using an RBF neural network through learning, and is serially connected in front of the composite controlled object, errors of a feedback signal and a given signal are input into an inverse controller, and accordingly closed-loop control is formed, then a self-adaptive parameter identifier is formed by using one RBF neural network through learning and identifies output quantity speed and displacement of the composite controlled object, speed-less and displacement-free sensor control is achieved, online learning of an estimation signal is aided by means of a learning algorithm, and non-linear dynamic decoupling control of the bearing-free asynchronous motor is achieved. The bearing-free asynchronous motor RBF neural network self-adaptive inverse decoupling control and parameter identification method is high in control speed and higher in identification accuracy, and a control system is excellent.

The invention relates to an open winding type permanent magnet motor driven reconstructed vehicle-mounted charging system for an electric vehicle. The system comprises a single-phase AC power supply,a rectifier bridge, an input filtering capacitor, three-phase voltage inverters, a three-phase permanent magnet motor winding, an output filtering capacitor, a storage battery and mode switches. The charging system sufficiently utilizes original double three-phase inverters, the permanent magnet motor winding, control and sensor units and the like of electric vehicles, and total integration of functions such as motor driving, high-power factor charging, harmonic control and the like is realized by optimizing topology to complete rectification, inversion and power factor correction. During charging, two three-phase voltage inverters are reconstructed into a three-phase cascading Buck-Boost circuit; the permanent magnet motor winding serves as an energy storage inductor of the three-phase cascading Buck-Boost circuit. By means of the charging system, the cost of a device can be effectively reduced and high-power factor charging can be realized.

Provided are a method for compensating instantaneous power failure in medium voltage inverter and a medium voltage inverter system by using the same, the method for compensating instantaneous power failure in medium voltage inverter including a plurality of power cells supplying a phase voltage to a motor by being connected to the motor in series, the method including decreasing an output frequency of the plurality of power cells by as much as a predetermined value at a relevant point where an input voltage of the plurality of power cells is less than a reference value, decreasing the output frequency at a predetermined deceleration gradient, and maintaining the output frequency during restoration of input voltage as long as a predetermined time, in a case the input voltage is restored.

A common-voltage compensation circuit functions to provide a crosstalk interference suppressing mechanism for use in a liquid crystal display having a liquid-crystal capacitor and a storage capacitor. The compensation circuit includes a buffer for receiving a preliminary common voltage, a current / voltage converter, a high-pass filter and a ripple-voltage inverter. The current / voltage converter is utilized for generating a liquid-crystal capacitor common voltage furnished to the liquid-crystal capacitor according to an output current of the buffer. The high-pass filter performs a high-pass filtering operation on the liquid-crystal capacitor common voltage for extracting a ripple voltage. The ripple-voltage inverter is employed to generate a storage capacitor common voltage furnished to the storage capacitor through performing an inverting operation on the ripple voltage based on the preliminary common voltage. The ripple voltage of the storage capacitor common voltage has a phase opposite to that of the liquid-crystal capacitor common voltage for suppressing crosstalk interference.

An apparatus for generating a three-phase pulse-width-modulation signal for a three-phase voltage inverter employing a semiconductor switching element includes a generating unit that generates the three-phase pulse-width-modulation signal based on at least one combination of three basic voltage vectors and at least a zero vector.

There are provided with a motor rotor (22) fixed to a turbine shaft (12) and rotating together with the turbine shaft, a motor stator (24) surrounding the motor rotor and fixed within a bearing housing (16), an inverted (26) converting a dc power into an ac power, and an inverter controller (28) controlling a frequency and a voltage of the ac power by the inverter. The inverter and the inverter controller are accommodated in a driver container (29), and are coupled to a compressor housing (20) by an insulating coupling member (30).

A liquid crystal device includes a lateral electric field mode liquid crystal element that controls alignment of liquid crystal molecules by applying an electric field in a direction of a substrate plane to a liquid crystal layer. A voltage inverter circuit is provided in each pixel circuit, and inverts a voltage applied to the liquid crystal element by switching the supply of each of the first and second voltages, supplied from a memory circuit, to between a first pixel electrode and a second pixel electrode of the liquid crystal element. A holding capacitor holds a voltage applied to the liquid crystal element. The voltage inverter circuit includes switching elements. One end of the holding capacitor is connected to at least one of a common connecting point of first and second switching elements and a connecting point of third and fourth switching elements.

A backlight assembly device includes lamps, an inverter, a sensing unit, a normal lighting determiner and an inverter controller. The inverter applies a control signal to the lamps to control operation of the lamps. The sensing unit outputs sensing voltages in response to currents flowing in the lamps. The normal lighting determiner compares the sensing voltages to a reference voltage for determining an operating state of the lamps to output a determination signal and varies the reference voltage in response to a change in the operating state of the lamps. The inverter controller outputs the control signal in response to the determination signal.

A medium voltage adjustable frequency drive includes an input isolation transformer having a three-phase input and a three-phase output, a converter having a three-phase input electrically connected to the three-phase output of the input isolation transformer and an output providing a direct current bus, an inverter having an input electrically connected to the output of the converter and a three-phase output, and a pre-charge circuit. The pre-charge circuit includes a ferro-resonant transformer circuit having a primary winding structured to input a low voltage and a secondary winding structured to output a medium voltage and provide a constant current source. The pre-charge circuit also includes a medium voltage diode bridge having an input receiving the medium voltage from the secondary winding of the ferro-resonant transformer circuit and an output structured to provide the constant current source to the direct current bus.

A voltage inverter capable of operating in the event of a short-circuit or open-circuit fault. The voltage inverter includes: a load having three phases, each phase having a first terminal and a second terminal; first and second cells each including three branches connected together in parallel, each branch including two switches connected in series and a mid-point positioned between the two switches, each first terminal of each of the phases being connected to one of the mid-points of the first cell and each second terminal of each of the phases being connected to one of the mid-points of the second cell; and a DC voltage source, the first and second cells each being connected to the DC voltage source via two electrical isolators.

The invention discloses a photovoltaic synchronization inverter with a photovoltaic array IV test function, which is composed of an inverter main circuit and a system controller; the inverter main circuit adopts an adjustable-voltage inverter and comprises a one-phase and three-phase synchronization system; the photovoltaic synchronization inverter is characterized in that: a current sensor CT1 for measuring photovoltaic array input current is arranged between a photovoltaic array input port and a filter capacitor C1; a direct-current bus bar voltage sensor VT1 for measuring the voltage of the filter capacitor C1 end is arranged; a direct-current breaker K1 is arranged at the photovoltaic array output port, the photovoltaic array output general current is input to the photovoltaic synchronization inverter, the direct-current bus bar voltage sensor VT1 and the current sensor CT1 through the direct-current breaker K1; the photovoltaic synchronization inverter is suitable for the conventional synchronization inverting system, can test the photovoltaic array IV characteristics of the system conveniently, and the test data is used for analyzing and evaluating the photovoltaic array characteristics of the system and the power generating capacity.

The invention discloses a control circuit applied to SOI (silicon on insulator) CMOS (complementary metal oxide semiconductor) radiofrequency switches. The control circuit comprises a band-gap reference circuit, a low-dropout linear voltage regulator, an annular oscillator, voltage inverters, a non-overlapping clock circuit, a charge pump and a level switching circuit. A core unit of the control circuit is a charge pump circuit capable of generating negative voltages. The band-gap reference circuit is connected with the low-dropout linear voltage regulator, an output end of the low-dropout linear voltage regulator is connected with the charge pump, an output end of the annular oscillator is connected with an input end of the inverter I2 by the inverter I1, an output end of the inverter I1 and an output end of the inverter I2 are connected with an input end of the non-overlapping clock generating circuit, four output ends of the non-overlapping clock generating circuit is connected with an input end of the charge pump, and the SOI CMOS radiofrequency switches can be controlled by an output end OUTPUT of the charge pump via the level switching circuit. The control circuit has the advantages that the charge pump capable of generating the negative voltages can be quickly started and has low steady-state currents, accordingly, radiofrequency switch tubes can be assuredly in excellent closed states under the conditions of high radiofrequency signals, and the linearity and the isolation of the radiofrequency switches can be improved.

The invention relates to a high-voltage inverter sharing a direct current (DC) bus. The high-voltage inverter sharing the DC bus comprises a charging circuit, a phase-shifting transformer, three-phase diode rectifier bridges, a high voltage DC bus and an inverter based on multi-media card (MMC) topology. The primary side of the phase-shifting transformer is connected with a power grid through the charging circuit, each subsidiary side output winding of the phase-shifting transformer is connected with the three-phase diode rectifier bridge, the output capacitors of each diode rectifier are connected in series to form the high voltage DC bus, the high voltage DC bus is connected with the public DC end of one inverter or multiple inverters based on MMC topology, and the output ends of the inverters are connected the electric motor to be detected, and the mixed frequency test and the frequency control function of the electric motor is achieved. The topologic scheme of the high-voltage inverter sharing the DC bus meets the requirements of the electric motor test station of a weak grid end, multiple-unit output of the phase-shifting transformer with multiple windings is used, the DC bus formed by the series connection of the diode rectifying capacitors is used to store the energy extracted and fed back when the electric motor mixed frequency test is carried out, the energy is no longer loaded by the power grid, and therefore the pollution to the power grid caused by the electric motor test is eliminated.

An apparatus includes a multi-channel DC bus assembly comprising a first channel and a second channel, a first electromechanical device coupled to a positive DC link of the first channel, and a second electromechanical device coupled to a positive DC link of the second channel. A first DC-to-AC voltage inverter is coupled to the positive DC link of the first channel and a second DC-to-AC voltage inverter is coupled to the positive DC link of the second channel. The apparatus further includes a bi-directional voltage modification assembly coupled to the positive DC link of the second channel and a first energy storage system electrically coupled to the first electromechanical device.

An apparatus for generating a three-phase pulse-width-modulation signal for a three-phase voltage inverter employing a semiconductor switching element includes a generating unit that generates the three-phase pulse-width-modulation signal based on at least one combination of three basic voltage vectors and at least a zero vector.