Abstract: In a power conversion device in a configuration in which a plurality of power converter cells has serially connected outputs and includes a converter and an inverter as components, when a load is light, the cells also operate with a light load, and efficiency is reduced. A power conversion device has a plurality of power converter cells. The outputs of the cells are connected in series. The device has a controller that controls the cells. The cells each have a converter that converts an externally inputted power supply voltage and generates a DC link voltage and an inverter that converts the DC link voltage into an alternating current voltage and outputs the current. The controller stops a converter in some of the cells depending on power supply electric power or load electric power. The inverter continues to operate using a link capacitor as a power supply.

Abstract: A power source equipment for power over Ethernet system comprising a plurality of power source devices, each configured to determine, after having determined the power source device is connected by an external device without a powered device (PD) signature, whether another power source device is connected by a power device with a PD signature. If the determination is positive, the two power source devices are determined having been connected by the same PD and power is supplied to the PD by the two power source devices.

Abstract: A method of controlling a power supply using software comprises setting a nominal output level through a waveform controlled by a micro-controller. The method identifies when a device is fully charged, and moves to a keep-alive mode, in which the output level is decreased below the nominal output level when the device is fully charged. The method further provides a failsafe to move the system to the keep-alive mode when the micro-controller is halted, crashed, in an error state.

Abstract: A method of controlling a plurality of power converters in a power system includes controlling switching times on the plurality of power converters receiving an input using a master controller, such that at least one of the plurality of power converters switches at a different time than at least one other of the plurality of power converters to provide a summation of outputs at a coupling point, and adjusting control signals from the master controller to each power converter to control the summation of the outputs to a desired output. A method of controlling a plurality of power converters in a power system includes determining a base frequency, assigning an operating frequency to the power converters, wherein the operating frequency is a multiple of the base frequency, to each of the power converters, operating the plurality of power converters at the assigned frequencies, and summing the individual outputs of the power converters to produce an output.

Abstract: A wireless-power-transfer system includes a transmitter circuit and a receiver circuit. The transmitter circuit includes a primary series-resonant capacitor connected to an oscillator-controlled drive stage that provides fixed-frequency output and a transmitting coil connected to the primary series-resonant capacitor. The transmitting resonant frequency is below the fixed frequency of the oscillator-controlled drive stage. The receiver circuit includes a receiving coil, a secondary series-resonant capacitor connected in series with the receiving coil, and a secondary parallel-resonant capacitor connected in parallel with the receiving coil. The receiving resonant frequency increases as a nonlinear capacitance of the at least one rectifier decreases when the rectifier-circuit DC output increases.

Abstract: A system comprises a plurality of power converters, a plurality of energy storage systems, a first common node, a second common node, and zero-reference voltage node. Each power converter is coupled between one energy storage system and the first and second common nodes. The system operates to regulate power between the power converters and the first and second common nodes. Each power converter is a bi-directional power converter and each energy storage system is a battery pack. In one example, the first common node is regulated to a voltage VSPAN, and the second common node is regulated to a voltage VSCN which is the mean of all voltages output by the battery packs. In another example, the first common node is regulated to a voltage ?VSPAN, and the second common node is regulated to a voltage +VSPAN. No power converter processes more than voltage VSPAN yielding high-efficiency power conversion.

Abstract: According to one aspect, embodiments of the invention provide a UPS system comprising an input, an output, a converter coupled to the input and configured to convert input power into DC power, a plurality of DC busses coupled to the converter and configured to receive the DC power from the converter, an inverter coupled to the plurality of DC busses and configured to convert the DC power from the plurality of DC busses into output AC power and provide the output AC power to the output, and a controller configured to operate the inverter, during a positive half-period of the line cycle, in a first mode of operation to provide a positive output voltage to the output, in a second mode of operation to provide a zero output voltage to the output, and a third mode of operation to provide a negative output voltage to the output.

Abstract: Systems and methods are herein disclosed for efficiently allowing current to bypass a group of solar cells having one or more malfunctioning or shaded solar cells without overwhelming a bypass diode. This can be done using a switch (e.g., a MOSFET) connected in parallel with the bypass diode. By turning the switch on and off, a majority of the bypass current can be routed through the switch, which is configured to handle larger currents than the bypass diode is designed for, leaving only a minority of the current to pass through the bypass diode.

Abstract: According to one aspect, embodiments of the invention provide a power supply system comprising an input, an output, a neutral point, a converter configured to convert input AC power into converted DC power, the converter including a first converter switch, a positive DC bus configured to receive the converted DC power, a negative DC bus configured to receive the converted DC power, an inverter configured to convert DC power from the positive and negative DC busses into output AC power, the inverter including a first inverter switch, and a clamp circuit coupled to the positive DC bus and coupled across at least one of the first converter switch and the first inverter switch, the clamp circuit configured, during switching operation, to clamp a voltage across the first converter switch and/or the first inverter switch to a voltage level of the positive DC bus or the negative DC bus.

Abstract: A system and method for conditioning DC power received from hybrid DC power sources is disclosed. A power conversion circuit is coupled to a respective DC power source to selectively condition the output power generated thereby to a DC bus voltage. The power conversion circuit includes a switch arrangement and capacitors arranged to provide a charge balancing in the power conversion circuit. A controller in operable communication with the switch arrangement receives inputs on a DC bus voltage and at least one parameter related to operation of the DC power source, and determines an adjustable voltage to be output from the conversion circuit to the DC bus based on the received inputs. The controller then selectively controls operation of the switch arrangement in order to generate the determined adjustable voltage.

Abstract: A multi-input power manager includes: first to n-th maximum power point tracking circuits for respectively receiving first to n-th powers from the outside and controlling voltages of first to n-th nodes to be first to n-th reference voltages based on the first to n-th powers; first to n-th input capacitors which respectively store the first to n-th powers by control of the first to n-th maximum power point tracking circuits, and are respectively connected to the first to n-th nodes; first to n-th transfer switches which are respectively connected to the first to n-th nodes, and output powers respectively stored in the first to n-th input capacitors, responding to first to n-th transfer switching signals; and a transfer switch control circuit which compare the first to n-th reference voltages and the voltages of the first to n-th nodes respectively, and generate the first to n-th transfer switching signals accordingly.

Abstract: A power conversion apparatus includes a main capacitor to store therein DC power, and an inverter circuit to convert the DC power stored in the main capacitor to AC power. The main capacitor and a power semiconductor element that constitutes the inverter circuit are connected to each other by a P-side common wire through which a switching current flows. A switching-current shunt component is connected in parallel to the P-side common wire.

Abstract: Output current ripple is reduced in a three-level DC-DC power converter by connecting a plurality of phase legs in parallel between a source of input power and an output of the power converter and conducting power from the source of input power to the power converter output in an interleaved manner. The large current that results from such interleaved operation is reduced to acceptable levels, potentially less than the output current ripple of the power converter by providing inversely coupled inductors having a mutual inductance preferably greater than the inductor of the power converter in respective phase legs and in series in the circulating current path to avoid any need to increase the power converter inductance due to the circulating current. The inductor and inversely coupled inductors are preferably integrated into a single magnetic element of compact design.

Abstract: An energy storage system includes a first energy storage, a second energy storage, a transformer, and circuitry. The first energy storage outputs a first output voltage. The second energy storage outputs a second output voltage. The transformer transforms at least one of the first output voltage and the second output voltage. The circuitry is configured to detect a sign of a fault in at least one of the first energy storage and the second energy storage. The circuitry is configured to control the transformer so as to transfer power from one energy storage among the first energy storage and the second energy storage to another energy storage among the first energy storage and the second energy storage in a case where the detector detects the sign of the fault in the one energy storage.

Abstract: A method is disclosed for controlling power distribution from a plurality of inverters to one or more loads. The method comprises determining, using one or more computer processors, a plurality of possible combinations of the plurality of inverters to meet load demands corresponding to the one or more loads. Each possible combination of the plurality of possible combinations includes a respective set of one or more inverters of the plurality of inverters. The method further comprises accessing, from a memory coupled with the one or more computer processors, one or more predefined efficiency functions associated with the one or more inverters; selecting, based on the one or more predefined efficiency functions, a combination from the plurality of possible combinations; and transmitting control signals to the set of one or more inverters corresponding to the selected combination to thereby power the one or more loads.

Abstract: A power converter controller and methods for its operation are provided that can control a self-oscillating power converter that uses a Bipolar Junction Transistor (BJT) as a switch by manipulating the current flowing in a control winding. The controller is able to determine the optimum time to remove a short circuit applied to the control winding, as well as being able to determine the optimum time to pass current through the control winding. The controller can further draw power from the power converter using the control winding. The controller is capable of maintaining the midpoint voltage of the power converter in the case that the converter has more than one switch. The controller estimates the output power of the converter without requiring a connection to the secondary side of the converter transformer. The controller further controls entry and exit into a low-power mode in which converter oscillations are suppressed.

Abstract: Circuits integrated or integrable with a photovoltaic panel to provide built-in functionality to the photovoltaic panel including safety features such as arc detection and elimination, ground fault detection and elimination, reverse current protection, monitoring of the performance of the photovoltaic panel, transmission of the monitored parameters and theft prevention of the photovoltaic panel. The circuits may avoid power conversion, for instance DC/DC power conversion, may avoid performing maximum power tracking to include a minimum number of components and thereby increase overall reliability.

Abstract: An apparatus comprises a power electronic energy conversion system comprising a first energy storage device configured to store DC energy and a first voltage converter configured to convert a second voltage from a remote power supply into a first charging voltage configured to charge the first energy storage device. The apparatus also includes a first controller configured to control the first voltage converter to convert the second voltage into the first charging voltage and to provide the first charging voltage to the first energy storage device during a charging mode of operation and communicate with a second controller located remotely from the power electronic energy conversion system to cause a second charging voltage to be provided to the first energy storage device during the charging mode of operation to rapidly charge the first energy storage device.

Abstract: A modular dc-dc boost converter system is provided that can substantially improve efficiency over a wide range of input and output voltages. The system includes three modules: a buck module, a boost module, and a dc transformer module. These modules are interconnected such that the system output voltage is equal to the sum of the output voltages of adc-dc converter module and a dc transformer module. Depending on the operating point, one or more modules may operate in passthrough mode, leading to substantially reduced ac losses. The required capacitor size and the transistor voltage ratings are also substantially reduced, relative to a conventional single dc-dc boost converter operating at the same input and output voltages.

Abstract: A method for controlling a switching circuit including an input port electrically coupled to a photovoltaic device and an output port electrically coupled to a load includes (1) entering a voltage limiting operating mode and (2) in the voltage limiting operating mode (i) causing a control switching device of the switching circuit to repeatedly switch between its conductive and non-conductive states in a manner which limits magnitude of an output voltage to a maximum voltage value, the output voltage being a voltage across the output port, and (ii) varying the maximum voltage value as a function of magnitude of an output current, the output current being a current flowing through the output port.

Abstract: The inverter circuit has a first silicon carbide MOSFET and a second silicon carbide MOSFET connected in series and external freewheel diodes respectively connected in anti-parallel to the first and second MOSFETs. The inverter circuit is configured such that during a deadtime when the first silicon carbide MOSFET and the second silicon carbide MOSFET are OFF and freewheeling current starts flowing, a pulse width of a transient current flowing to a built-in diode of the first silicon carbide MOSFET or a built-in diode of the second silicon carbide MOSFET is less than 2 ?s.

Abstract: An energy system for renewable energy applications includes a renewable energy source, a bidirectional inverter connected an AC bus and a DC bus, an energy storage unit connected to the bidirectional DC/DC converter, and a control system comprising one or more controllers coupled to the bidirectional inverter and the bidirectional DC/DC converter. The bidirectional inverter is connected to the renewable energy source and a bidirectional DC/DC converter through the DC bus. The system is configured to capture low power of a photovoltaic (PV) array, energy typically lost to inverter clipping, and through the utilization of ramp rate control.

Abstract: A method includes activating electrochemical cells of a cell assembly to output electrical energy in accordance with a superordinate clock signal in order to have an activation and/or switch-off time points of the respective cells on the basis of the superordinate clock signal not all occur at the same time. To reduce the complexity of smoothing the total battery voltage, the switching time points according to the disclosure are shifted on the basis of the superordinate clock signal for the first cell in accordance with a first switching specification by a cell-specific first clock shift signal.

Abstract: Methods and apparatus may provide for the adaptive operation of a solar power system (3). Solar energy sources (1) and photovoltaic DC-DC power converters (2) may be interconnected in serial, parallel, or combined arrangements. DC photovoltaic power conversion may be accomplished utilizing dynamically adjustable voltage output limits (8) of photovoltaic DC-DC power converters (2). A photovoltaic DC-DC power converter (2) may include at least one external state data interface (7) receptive to at least one external state parameter of a solar power system (3). A dynamically adjustable voltage output limit control (12) may be used to relationally set a dynamically adjustable voltage output limit (8) of a photovoltaic DC-DC power converter (2). Dynamically adjusting voltage output limits (8) may be done in relation to external state parameter information to achieve desired system results.

Abstract: A communication host and a photovoltaic power generation system are provided. The communication host includes an acquiring module, a determining module and a control module. The acquiring module is configured to acquire an operating state parameter of the system. The determining module is configured to determine whether the optimizer meets a first preset triggering condition based on the operating state parameter. In a case where the optimizer meets the first preset triggering condition, a first triggering instruction is transmitted, to instruct the system to decrease, in response to the first triggering instruction, the direct current bus voltage of the grid-connected inverter, and/or a second triggering instruction is transmitted, to instruct the system to increase, in response to the second triggering instruction, an output voltage limiting value of at least one of the optimizers meeting the first preset triggering condition.

Abstract: An inverter system includes an input inverter including a positive and a negative DC input terminals and first and second AC output terminals; and a bidirectional inverter device, including a first bidirectional subinverter and a second bidirectional subinverter. The first and second bidirectional subinverters have DC terminals that are interconnected in parallel with a DC power storage device. The first bidirectional subinverter have first and second AC terminals. The first AC terminal is connected to the first AC output terminal of the input inverter. The second bidirectional subinverter have first and second AC terminals. The first AC terminal is connected to the second AC output terminal of the input inverter. The second AC terminal of the first bidirectional subinverter and the second AC terminal of the second bidirectional subinverter are interconnected.

Abstract: A DC/DC converter includes a first low-voltage terminal point, a second low-voltage terminal point and a third low-voltage terminal point, and a first high-voltage terminal point and a second high-voltage terminal point. The first low-voltage terminal point and the first high-voltage terminal point are directly connected to one another, and an actively drivable switching element, a capacitor and a further switching element are connected in series between the first high-voltage terminal point and the second high-voltage terminal point. The capacitor is connected between the second low-voltage terminal point and the third low-voltage terminal point, a further capacitance is directly connected between the second low-voltage terminal point and the third low-voltage terminal point, and the further capacitance is decoupled from the capacitor at two terminals by two inductors, respectively.

Abstract: An inverter device includes a circuit configuration for converting, to AC power, DC powers respectively given from a first power supply and a second power supply which outputs power with voltage lower than that of the first power supply. The inverter device includes: a first step-up circuit; a second step-up circuit; an inverter circuit connected to both step-up circuits connected in parallel to each other, the inverter circuit configured to convert powers given from both step-up circuits to AC power; and a control unit configured to multiply a power value including the AC power outputted from the inverter circuit, by a ratio of a power value of the DC power of each step-up circuit to a total power value obtained by summing the DC powers of both step-up circuits, and set a current target value for each step-up circuit based on a value obtained by the multiplication.

Abstract: Systems and methods for controlling an energy storage system are provided. In particular data indicative of a load profile can be received. The load profile can specify one or more amounts of power to be delivered by an energy storage system over a duration. The energy storage system can include one or more energy storage elements of a first type and one or more energy storage elements of a second type. One or more time windows associated with high power events and one or more time windows associated with high energy events can then be determined based on the load profile. Power delivery by the energy storage elements of the first type and the energy storage elements of the second type can then be controlled based at least in part on the determined time windows.

Abstract: Methods and apparatus for controlling a voltage source converter to energize a DC link. A voltage order generating module generates a voltage order for controlling the voltage source converter to generate a DC voltage on the DC link. the voltage order is based on a time varying voltage reference signal. A voltage reference module, which may include a ramp generator generates the time varying voltage reference signal such that the rate of change of the voltage reference signal changes over time. The rate of change of the voltage reference signal may decrease over time, to become more gradual as the nominal operating voltage is reached to avoid over-voltages.

Abstract: A power converter includes a power conversion circuit converting an input voltage into an output voltage, and a feedback control circuit including a voltage detector module generating a feedback signal having a signal frequency proportional to a magnitude of the output voltage, a phase detector module generating counting-up and counting-down signals based on the signal frequency and a reference frequency, and a control input generator module controlling the power conversion circuit to adjust the output voltage based on the counting-up and counting-down signals. The logic levels of the counting-up and counting-down signals are maintained until a relative relationship between the signal frequency and the reference frequency changes.

Abstract: An electrified vehicle high voltage battery pack has series-connected battery units or cells combining to provide the high voltage. To power a low voltage bus (e.g., for low voltage accessories or charging a low voltage battery) in a balanced manner, a plurality of DC/DC converters each has an input coupled to a respective battery unit and the converters have respective outputs coupled in parallel to the low voltage bus. A first loop controller receives an actual bus voltage. The first controller generates a target current in response to the bus voltage adapted to regulate the actual bus voltage to a target voltage less than the high voltage. A second controller distributes the target current into a plurality of allocated current commands for respective converters according to respective states of charge of the battery units connected to the converters.

Abstract: To establish a system capable of efficient operation control between a plurality of distributed power sources without undermining the versatility of the distributed power sources, a power control system controls a power generation device and other distributed power sources, the power generation device generating power while a current sensor detects forward power flow. The power control system includes: a power control device including an output unit configured to output power supplied from the other distributed power sources, in a state where the power generation device and the other distributed power sources are paralleled off from a grid; and a dummy output system configured to supply a dummy current detectable by the current sensor as a current in the same direction as the forward power flow, using an output from the output unit, wherein the dummy output system includes step-down unit located between the output unit and the current sensor.

Abstract: A multiphase power supply includes a multiphase converter including first and second converters having differing operating phases, each of the first and second converters configured to convert input power into driving power, and transmit the driving power to a power amplifier, a detector configured to detect a voltage based on the driving power, and a duty controller configured to compare an error voltage between an envelope signal of an input signal input into the power amplifier and the detected voltage and sawtooth wave signals having different phases from each other to generate duty control signals, wherein the duty controller compares the error voltage and the sawtooth wave signals with each other using a single comparator.

Abstract: Disclosed is a subnetwork controller for a subnetwork within an interconnected grid. The controller controls power generators, subnetworks, or loads of the subnetwork in accordance with sensor-captured internal measured variables and sensor-captured external measured variables as well as external controlled variables of the subnetwork in such a way that a dynamic behavior of the subnetwork in relation to its adjacent subnetworks corresponds to a defined desired behavior.

Abstract: An improved interface for renewable energy systems is disclosed for interconnecting a plurality of power sources such as photovoltaic solar panels, windmills, standby generators and the like. The improved interface for renewable energy systems includes a multi-channel micro-inverter having novel heat dissipation, novel mountings, electronic redundancy and remote communication systems. The improved interface for renewable enemy systems is capable of automatic switching between a grid-tied operation, an off grid operation or an emergency power operation.

Abstract: An LED driver design has a single controller used to drive multiple strings of LEDs. In one aspect there is dynamic threshold voltage setting so that the individual characteristics of the LED strings can be taken into account in the voltage control loop. In another aspect, excess energy is dissipated off-chip in a dedicated heat dissipater, and the routing of current to the heat dissipater is controlled dynamically such that a desired integrated circuit biasing remains stable.

Abstract: In a first section including a point of time when sums of periods while upper arm-side switches in a pair of current paths of a voltage source inverter conduct in one cycle of a carrier are equal to each other at zero, a first voltage command group corresponds to switching signals in which a period while the upper arm-side switches in all of the current paths are nonconductive in this one cycle is adjacently sandwiched by a pair of periods while all of the upper arm-side switches in the pair of current paths are nonconductive and other upper-arm side switch conducts.

Abstract: A static synchronous compensator device connected between a source and a load of a three-phase power system, comprising: a main feedback line configured to provide a main feedback signal from lines between the source and the load; a mixer configured to mix the main feedback signal with a balance function to generate a balanced signal; a signal controller configured to convert the balanced signal to a controlled signal; a gain circuit configured to multiply the controlled signal by ?1 and to perform proportional gain and integral gain (P & I) processing on the controlled signal to generate an intermediate correction signal; and a pulse width modulator configured to apply a pulse width modulation pattern to modulate the voltage source inverter to generate an AC waveform that is applied to the lines between the source and the load.

Abstract: A battery charger for electric vehicles includes at least three identical current controlled AC-DC converter modules having reverse current protected outputs connected in parallel to a charge terminal of the battery.

Abstract: The module according to the present invention is used for accumulating/drawing electricity in/from an electric accumulator (502); the module comprises first terminals and second terminals; the first terminals are adapted to be connected to a photovoltaic panel (501) and to an inverter (504), and the second terminals are adapted to be connected to the electric accumulator (502); the module comprises a conversion unit (503) adapted to be connected between the first terminals and the second terminals; the conversion unit (503) comprises, in turn, a two-way DC/DC converter (550) adapted to convert a first energy flow generated by the photovoltaic panel (401, 501) to store it in the accumulator (502) and a second energy flow drawn from the accumulator (502) to supply it to the inverter (504), the two-way DC/DC converter (450, 550) is configured to convert said first energy flow and said second energy flow in a selective manner.

Abstract: A power controller of a hybrid vehicle includes: a first drive motor that drives any one of a front wheel and a rear wheel of a vehicle; an engine that drives the one wheel or the corresponding other one of the front wheel and the rear wheel of the vehicle through a clutch; a generator that is driven by the engine; and a voltage transformer that steps down generated electric power supplied to the first drive motor and a battery from the generator. The power controller limits passing power of the voltage transformer according to the temperature of the voltage transformer, and connects the clutch when the passing power of the voltage transformer is limited.

Abstract: The invention relates to a control system for compensating undesired electrical harmonics on an electrical grid. Part of the control system referred to as a harmonic compensator is operatively connected with a power inverter of a power producing unit supplying power to the grid. Another part of the control system, referred to as an impedance detector, is operatively connected to a point of coupling to which point one or more power producing units are connected. The impedance detector is configured to scan impedances as a function of frequency to identify frequencies of impedance peaks which peaks are indicative of resonance frequencies. The determined resonance frequencies are supplied to one or more the harmonic compensators. A compensator determines control signals to the inverter which causes the inverter to inject compensation currents to the grid which currents will damp currents oscillating at or close to the determined resonance frequency.

Abstract: According to one embodiment, a drive device drives “N” number (N is an integer of “2” or greater) of inverters to generate AC power and transmit respective AC power to transmission coil units corresponding thereto and includes a switching signal generation circuit. The switching signal generation circuit generates switching signals to drive first to fourth switching elements of each inverter to complementarily drive the first switching element and the second switching element, and complementarily drive the third switching element and the fourth switching element so that a phase difference between an output current of an “M”th (“M” is an integer of 2 or greater and “N” or below) inverter and an output current of an “M?1”th inverter becomes or approach “360×L/N” degrees (“L” is an integer of “1” or greater and less than “N”) and supplies the switching signals to the first to fourth switching elements of the inverters.

Abstract: A motor drive device includes a forward converter, reverse converter, DC link capacitor, voltage detection part, first storage part storing a threshold for the non-energized period in which the leakage current of the capacitor increases and a threshold for the applied voltage for reducing the leakage current of the capacitor, a second storage part that records a previous energization period of the capacitor, and a control part, in which the control part obtains the non-energized period of the capacitor based on the previous energization period recorded, during activation of the motor drive device, and in a case of the non-energized period obtained being longer than the threshold for the non-energized period stored, causes regeneration operation from the motor to the power supply to stop, and causes the voltage of the capacitor to rise up to the threshold for the applied voltage stored, by way of deceleration energy of the motor.

Abstract: The present invention relates to an intra-module DC-DC power converter and a Photovoltaic (PV) module comprising same. The switching frequency of said intra-module DC-DC power converters may be 500 kHz. The PV module may have a controller and a plurality of switches for allowing each individual string of said PV module to be connected to one corresponding DC-DC converter, or for allowing two or more strings of said module to be connected in series and to apply the voltage of the combined string to a single DC-DC converter. The input voltage range of the DC-DC converters may be 10V to 30V, and the output voltage range may be 120V. The DC-DC converters may be connected in series or in parallel. Multiple such PV panels may be connected in a DC-grid.

Abstract: Disclosed embodiments relate to power supply systems for supplying power. In some embodiments, a power supply system includes: a plurality of power conversion systems configured to receive and convert DC power from a power generator which generates power or an energy storage system which discharges stored energy; and a system controller configured to transmit a control instruction to control the plurality of power conversion systems based on a transmission protocol depending on an attribute of the control instruction.

Abstract: A power supplying apparatus includes a first piezoelectric transformer operated at a first operating frequency, a second piezoelectric transformer operated alternately with the first piezoelectric transformer and operated at a second operating frequency, wherein the second operating frequency is a multiple of the first operating frequency.

Abstract: In accordance with an embodiment, a method includes converting power by a power converter circuit having a plurality of converter cells coupled to a supply circuit. Converting the power includes a plurality of successive activation sequences and, in each activation sequence, activating at least some of the plurality of converter cells at an activation frequency. The activation frequency is dependent on at least one of an output power and an output current of the power converter circuit.

Abstract: The present invention discloses a driving circuit and a liquid crystal display device. The driving circuit has: a first to fourth diodes, a first and second capacitors, and an adjustable voltage source, An anode of the first diode inputs a voltage, cathodes of the first to third diodes are connected to anodes of the second to fourth diodes, a cathode of the fourth diode outputs a voltage, a first end of the first capacitor is connected to a common end of the first diode and the second diode, a second end of the first capacitor is connected to an output terminal of the adjustable voltage source, and a selective terminal thereof is used to input a selective voltage; when an input voltage is not changed, the selective voltage is different and an output voltage is different. The above-mentioned method can provide multiple different output voltages to meet with client's requirements.