52results about "Ac-dc conversion" patented technology

The following problem associated with a semiconductor device of silicon or the like having low band gap is solved by temperature estimation using voltage drop in such a semiconductor device having low accuracy and this complicates a circuit for temperature detection suitable for practical use or a configuration for implementing a detection system. A power converter provided with an inverter circuit includes a semiconductor device whose band gap is larger than that of silicon and which has a range in which the temperature coefficient of voltage drop during conduction is positive. The power converter further includes a measurement condition setting circuit. This circuit adjusts the timing of the following measurement values used for temperature estimation at a device temperature estimation circuit to each other so that a measurement value of a voltage measurement circuit and a measurement value of a current measurement circuit become data obtained by measurement at the same time.

A method and apparatus for LCL resonant converter control utilizing Asymmetric Voltage Cancellation is described. The methods to determine the optimal trajectory of the control variables are discussed. Practical implementations of sensing load parameters are included. Simple PI, PID and fuzzy logic controllers are included with AVC for achieving good transient response characteristics with output current regulation.

The present invention relates to a differentiated control method of the cascaded active power filter, wherein the cascaded links are divided into low frequency links and high frequency links; wherein low frequency links are used to generate the fundamental voltage generated by the cascaded multilevel converter; wherein high frequency links are used to produce different, separate voltage from the aforementioned fundamental voltage generated by the cascaded multilevel converter; wherein according to the given cycle, some links are selected circularly from cascaded links as the high frequency links; wherein in the control cycle, each phase links with the maximum and minimum DC capacitor voltage, as well as those links that the pulse width modulation (PWM) combination discharge and charge most to DC capacitor are found out.

The invention discloses a main circuit of a three-phase four-wire DC/AC convertor and a control method thereof. The main circuit comprises two power semiconductor switches G1 and G2, two diodes D1 and D2, a capacitance branch and an inductor L1, wherein the two power semiconductor switches G1 and G2 are connected with a bridge arm with midpoint drifting control in series from top to bottom; the two diodes D1 and D2 are connected with power semiconductor switches in parallel reversedly; the capacitance branch is connected with the bridge arm with the midpoint drifting control in parallel; the capacitance branch is formed by two series capacitors C1 and C2; and one end of the inductor L1 is connected with the point of common coupling (PCC) of the two semiconductor switches G1 and G2, and the other end of the inductor L1 is connected with the PCC of the two series capacitors C1 and C2, as well as a midcourt line in the three-phase four-wire convertor is led out, namely an N line. In the invention, the bridge arm in a midpoint control circuit and three bridges of a three-phase convertor can be controlled respectively and independently, thus realizing decoupling control of a three-phase four-bridge arm convertor. Under the condition of three phase imbalance, simple voltage current feedback control or proportional-integral (PI) control is used to control the midpoint, so that the midpoint drifting control can be finished.

A semiconductor device includes: a semiconductor chip including a nitride semiconductor layered structure including a carrier transit layer and a carrier supply layer; a first resin layer on the semiconductor chip, the first resin layer including a coupling agent; a second resin layer on the first resin layer, the second resin layer including a surfactant; and a sealing resin layer to seal the semiconductor chip with the first resin layer and the second resin layer.

The power supply includes parts: power end, high voltage circuit (HVC) connected to the power end, first logic control circuit in use for controlling and driving HVC, the filament circuit (FC) with its input end being connected to the power end, and second logic control circuit in use for controlling and driving FC. The method includes steps: variable frequency control is adopted in the power portion in high voltage; adjusting switching frequency adjusts the input power; using voltage feed forward ensures stable output power approximately when the voltage of input power source changes; half bridge circuit (HBC) or single tube circuit (STC) is adopted in FC; the on time of one switch tube in HBC is fixed, and the on time of the other switch tube is varied with feed back. Main circuit decides the turn off time of STC, and turn on time is controlled by feedback. Scheme of separating FC from HVC possesses high adaptability to magnetron, single tube adopted in HVC so as to lower cost.

The invention belongs to the technical field of electrical energy exchange, and relates to a wide range voltage adjustable buck-boost single-stage inverter circuit device. The device adopts the structure that one end of switch tube is electrically connected with a positive pole of a direct current supply, and the other end of the switch tube is electrically connected with one end of an inductor; one end of the inductor is electrically connected with the negative pole of the direct current supply; the positive pole of an electrochemical capacitor and the inductor are commonly connected with the negative pole of the direct current supply so as to form a local loop with a three-phase voltage type bridge-type inverter circuit which comprises six bridge arms, each bridge arm is composed of an isolated gate bipolar triode transistor and an antiparallel diode; the output end of the three-phase voltage type bridge-type inverter circuit are led out by three groups of mutually corresponding bridge arms; the three-phase voltage type bridge-type inverter circuit is the output end of the whole device and used for receiving the DC electric energy and outputting AC electric energy. The device has the advantages of good safety, less passive elements of the inverter circuit, small size, light weight, environmental protection, and wide voltage adjustable range.

The invention discloses a control method for a VIENNA rectifier of an aviation multi-electric engine. The control method comprises the following steps: establishing a stationary coordinate system of the VIENNA rectifier and obtaining a mathematical model under a two-phase rotating coordinate system by coordinate transformation; taking a DC side voltage as a control variable, and designing a sliding mode surface based on a global terminal sliding mode theory to design a voltage external loop controller; and taking the DC side voltage and a derivative thereof as input of fuzzy reasoning, and adjusting the sliding mode reaching law in real time according to the output sliding mode in a system state so as to control the DC side voltage. According to the control method disclosed by the invention, the robustness of the system can be improved by virtue of the global terminal sliding mode theory and an error is restrained to be zero within a definite time; the sliding mode reaching law is controlled in real time according to the experience of an expert by virtue of a fuzzy reasoning theory, so that not only is the quickness of system response improved, but also buffeting is effectively weakened.

The invention relates to an intelligent power supply device for a low-temperature etching-free iron plating process, which is characterized in that three-phase alternating current supplies power for a silicon controlled rectifying circuit; an input end of the silicon controlled rectifying circuit is connected with a signal output end of a pulse signal generator; an output end of the silicon controlled rectifying circuit is connected with low-temperature iron plating loads; and signal output ends of a synchronizing signal generator and a PLC (programmable logic controller) are respectively connected with a signal input end of the pulse signal generator. The invention also discloses a power supply method of the intelligent power supply device. Phase-shifting control signals generated by the PLC are used for controlling the pulse signal generator, thus adjusting AC (alternating-current) and DC (direct-current) amplitudes; and AC and DC switching signals generated by the PLC are used for mutually switching between AC output and DC output. The power supply device is used for setting output duration of DC signals and output duration of AC signals, can be controlled automatically without manual operations, and is strong in reliability of power supply and convenient to operate.

The invention discloses a rectifier circuit for piezoelectric energy collectors to solve the problem that the energy consumption of an existing circuit is high and the efficiency of a piezoelectric energy collector is low when the rectifier voltage of the piezoelectric energy collector is greater than 2.5 V. The rectifier circuit comprises a full-wave rectifier bridge (2) and an active diode circuit (4), and further comprises a bias circuit (3). The output end of the full-wave rectifier bridge (2) is connected with the input ends of the active diode circuit (4) and the bias circuit (3). The output end of the bias circuit (3) is connected with the bias voltage end of a comparator in the active diode circuit (4). The output end of the active diode circuit (4) is connected with an energy storage capacitor C3. The rectifier circuit for piezoelectric energy collectors has the advantages of being low in power consumption, high in energy conversion efficiency, and capable of ensuring the energy demand of wireless sensor network node load.

The invention relates to the field of power management, and provides a Buck type high power factor converter based on an integrated controller. In order to achieve high power factors, according to the technical scheme, the Buck type high power factor converter based on the integrated controller comprises a peripheral circuit, a rectifying bridge is composed of four diodes, and a partial voltage structure which is formed by two resistors which are in series connection is connected to the rear portion of the rectifying bridge in parallel; the positive output end of an AC input power source is connected to the negative electrode of one diode, the negative output end of the AC input power source is connected with an MOS switch through a current detecting resistor, and the other end of the MOS switch is connected with the positive electrode of the corresponding diode. The positive electrodes of the diodes are connected with one end of a voltage reduction inductor. An output load is connected with a difference partial voltage structure in parallel. Middle nodes of the two resistors are connected to the base electrode of a P-type audion, a high level end is connected to the emitting electrode of a secondary audion after passing through an emitting electrode resistor, a collector electrode is connected to the ground after passing through a collector electrode resistor, and a node between the collector electrode and the resistors outputs voltage feedback signals. The Buck type high power factor converter based on the integrated controller is mainly suitable for power source management.

The invention relates to a circuit for realizing constant current control in a primary control switch power converter. The circuit comprises a controller, wherein the controller comprises a sampling/holding circuit, a voltage/current conversion circuit, an oscillator circuit, a flip-flop and a current limiting comparator; the sampling/holding circuit samples and holds feedback voltage VFB and inputs the feedback voltage VFB to the voltage/current conversion circuit; the voltage/current conversion circuit converts the feedback voltage VFB to obtain required control current; the oscillator circuit outputs a corresponding oscillation frequency signal according to the control current, and inputs the oscillation frequency signal to a setting end of the flip-flop; when the oscillation frequency signal is at a high level, an output ends of the flip-flop outputs a high level signal to switch on a driving power tube; and when sampling voltage VCS is higher than reference voltage VREF of an antiphase end of the current limiting comparator, the current limiting comparator outputs a current limiting signal to allow the flip-flop to output a low level so as to switch off the power tube. The circuit is compact in structure, wide in application scope, safe and reliable, and can realize the constant current control.

The invention relates to a current-type reduced matrix converter which includes a three-phase input power supply, an input filter, a matrix chopper, a high-frequency transformer, a current chopper, anoutput filter, and a load. The output ports R, S, T of the three-phase input power supply are correspondingly connected with the input ports R0, S0, T0 of the input filter. The output ports r1, s1, t1 of the input filter are correspondingly connected to the input ports r2, s2, t2 of the matrix chopper. The primary ports A, B of the high-frequency transformer are correspondingly connected with theoutput ports A0, B0 of the matrix chopper. The secondary ports a, b of the high-frequency transformer are correspondingly connected to the input ports a0, b0 of the current chopper. The output portsw, v of the current chopper are correspondingly connected with the input ports w0, v0 of the output filter. The output ports w1, v0 of the output filter are correspondingly connected with the ports w2, v2 of the load. The invention further discloses a control method of the converter. The current-type reduced matrix converter has excellent performance and high efficiency.

A coil module includes a magnetic substance plate, a first coil, and a second coil. The magnetic substance plate includes a first area having a first magnetic permeability and a second area having a second magnetic permeability. The first coil is disposed on a surface of the magnetic substance plate. The second coil is disposed on the surface of the magnetic substance plate and partially overlapping the first coil. A portion of the first coil, not overlapping the second coil, is disposed on a surface of the first area, and a portion of the second coil, not overlapping the first coil, is disposed on a surface of the second area.

A circuit device used for driving high voltage discharge lamp consists of DC power supply; DC-AC bridged unit; coupled ignition unit and control circuit including low frequency oscillator, PWN controller and driving circuit.

A high power control system includes: a single energy source; an energy source management unit configured to manage the energy source; a controller configured to output a PWM control signal under control of the energy source management unit; a plurality of inverters configured to convert a direct current into an alternating current under control of the PWM control signal of the controller; a plurality of filters coupled to output terminals of the inverters; and a plurality of switches configured to regulate connections between the filters and a load under control of a regulation control signal of the controller.

The invention discloses a modulation and voltage stabilization control method suitable for a single-power binary hybrid cascaded H-bridge multilevel inverter. In modulation, a modulated wave vm obtained through taking an absolute value of a sinusoidal modulated wave vref is compared with triangular carriers vca, vcb', vcr1' and vcr2' and a voltage constant value 2E to obtain five logic pulse signals A, B, R1, R2 and P; the sinusoidal modulated wave vref is compared with zero voltage to obtain a polar pulse signal D; and an optimized PWM drive signal is generated from the logic pulse signals and the polar pulse signal through a drive logic operational circuit. In voltage stabilization control, real-time adjustment is carried out on amplitudes of triangular carriers vcb, vcr1 and vcr2 through a signal obtained through operation of DC side voltage sampling signals Vdc1 and Vdc2 and voltage reference signals Vdc1* and Vdc2* of auxiliary units, thereby achieving voltage stabilization control on the auxiliary units through combining modulation. According to the control method disclosed by the invention, the stability of capacitor voltage can be controlled, output levels and the equivalent switching frequency of output voltage of the inverter can be improved and the output characteristics of a system are improved.

The invention discloses an integratable power supply filtering circuit, which comprises a rectification circuit, N levels of pulsating direct current electric charge shifting and voltage merging rectification circuits and N levels of electronic filtering circuits, wherein the rectification circuit consists of a bridge type rectifier DW1; the N levels of pulsating direct current electric charge shifting and voltage merging rectification circuits comprise at least N levels of pulsating direct current electric charge shifting unit circuits and at least N+1 levels of voltage merging rectificationunit circuits; each level of pulsating direct current electric charge shifting unit circuit consists of a resistor, a capacitor and a transistor; each level of voltage merging rectification unit circuit consists of a diode and a transistor; and the N levels of electronic filtering circuits comprise at least one unit electronic filtering circuit, wherein each unit electronic filtering circuit consists of two audions, seven resistors, one capacitor and an operational amplifier.

A forward power converter with a self-excited synchronous rectifying circuit makes use of the self-excitation function of a transformer to generate electric energy at a secondary side winding coil of the transformer, hence controlling an n-channel FET to accomplish synchronous rectification. In the synchronous rectifying circuit, the drain of the n-channel FET is connected to an end of the secondary side of a first transformer, the source of the n-channel FET is connected to a positive end of a flywheel diode, the negative end of the flywheel diode is connected to the other end of the secondary side of the first transformer, a control end of the n-channel FET is connected to an end of an induction coil via a resistor and a capacitor, and the other end of the induction coil is connected to the source of the n-channel FET.

The invention provides an IGBT control method based on MMC-HVDC, comprising the following steps: according to the obtained current working state of each sub-module on the same bridge arm, dividing each sub-module into an input group and a cut-off group; sorting each sub-module of the input group and each sub-module of the cut-off group according to the magnitude of the sub-module voltage; making The difference between the expected input sub-module number and the input sub-module number in the input group to generate the input sub-module difference value; according to the current direction of the bridge arm where each sub-module is located, selecting the conditional relationship; generating an optimal exchange value according to the input sub-module difference and the conditional relation;and adjusting the submodule states of the input group and the submodule states of the cut-off group according to the optimal exchange value. The invention has the beneficial effects of regulating thevoltage fluctuation amplitude of the capacitance of the bridge arm sub-module (i.e., voltage equalization effect), optimizing the average switching frequency of the IGBT of the MMC valve group, prolonging the service life of the IGBT, reducing the loss of the MMC valve group and improving the engineering reliability.