148results about How to "Reduce switching losses" patented technology

The invention discloses a grid-connected photovoltaic inverter and relates to equipment which employs irreversible DC power input conversion as AC power output for a semiconductor device with a control electrode and is used for being used together with a power supply system of a power supply. The equipment consists of a photovoltaic array module, four identical switching tubes, two identical diodes, four identical capacitors, an inductor and a power grid; and the topology ensures not to generate DC component or common mode current for the power grid. Meanwhile, the inverter has low output current ripple and higher efficiency, and overcomes the defects that the conventional full-bridge inverters and other types of transformerless photovoltaic inverters generate DC component in the power grid and generate common mode current or/and higher current ripple. Compared with a half-bridge inverter, the grid-connected photovoltaic inverter reduces the differential mode voltage and current ripple by half.

The configurations of a bridgeless PFC circuit system and a controlling method thereof are provided. The proposed system includes a bridgeless PFC circuit having a first and a second input terminals, a first switch having a first terminal, a first inductor having a first terminal coupled to the first input terminal and a second terminal coupled to the first terminal of the first switch, and a second inductor having a first terminal coupled to the second input terminal, a first auxiliary winding coupled to the first inductor and generating a first sensing signal, and a second auxiliary winding coupled to the second inductor and generating a second sensing signal, wherein the first and the second sensing signals are used to generate an inductor current sensing signal controlling the switching of the first switch accordingly.

A power converter system including an LC oscillator circuit, an oscillator drive circuit for driving the LC oscillator circuit, a rectifier circuit coupled to the LC oscillator circuit for providing a DC output, and a switching circuit for controlling the duty cycle of the oscillator drive circuit to modulate the power in the LC oscillator circuit and the rectifier circuit.

A method for controlling a bidirectional DC-DC converter that reduces switching loss during a step-down operation and conduction loss caused by synchronous rectification, while enabling bidirectional operation with the same control. The DC-DC converter includes first and second switch elements for alternately applying voltage in opposite directions to a transformer winding during the step-down operation and performing synchronous rectification during a step-up operation. Third and fourth switch elements perform synchronous rectification during the step-down operation and alternately apply voltage in opposite directions to the transformer in the step-up operation. The method includes activating the first switch when the third switch is in an active state, activating the second switch when the fourth switch is in an active state, switching each of the third and forth switches between an active state and an inactive state while inactivating the third or fourth switch.

The invention relates to a control method for an auxiliary switching tube of an active clamp flyback converter. In the flyback converter, severe energy loss and voltage spike of a main switching tube are caused due to leakage inductance of a transformer and leakage inductance of circuits. The conventional solution mainly comprises methods for solving the problems by using residual current device (RCD) clamp, liquid crystal display (LCD) clamp and active clamp, wherein an active clamp circuit can effectively recover leakage inductance energy and obviously improve the efficiency. The invention provides a novel control method on the basis of the conventional active clamp flyback converter topology. In the conventional control method, a primary side switching tube is in complementary conduction with an auxiliary switching tube in each period; and in the control method, the primary side switching tube is switched on in each period, the auxiliary switching tube is controlled by setting voltage of a clamp capacitor in the clamp circuit, and when the voltage of the clamp capacitor reaches the set value, the auxiliary switching tube is switched on. Compared with the prior art, the method has the advantages that: the switching loss of the auxiliary switching tube can be reduced; and more importantly, the efficiency of the circuit can be greatly improved under a light load, and the no-load loss is reduced.

A multiphase converter comprising a plurality of converter circuits, each converter circuit having series connected high and low side switches connected across a voltage bus with a common node provided therebetween, each of the common nodes connected through a respective inductor to an output node of the converter coupled to a load, the high and low side switches each being controlled by a control circuit to provide a desired output voltage at the output node, the control circuit including a first circuit for disabling and enabling at least one phase in response to a condition of the load, the circuit causing the high side switch to be turned on prior to the lower side switch when a disabled phase is enabled.

The invention discloses a linear servo motor control method for numerically-controlled machine tool driving. According to the method, a sine wave linear motor is controlled through a feedback signal detection module, a position control ring, a speed control ring and a current control ring, and the feedback signal detection module comprises a position detection module, a speed detection module and a current detection module, wherein the position control ring adopts a composite control method combining PI (proportional-integral) feedback control and neural network given compensation control, the speed control ring adopts a fuzzy controller with a disturbance observer, and the current control ring adopts a space vector PWM (pulse-width modulation) technology with a PI regulator. The linear servo motor control method has the advantages that the neural network compensation PI control technology, the fuzzy control and the alternating current motor vector control are combined, and the anti-jamming capability, the dynamic response capability and the system stable state precision of a linear servo motor are improved.

The invention relates to a composite type traction power supply device which can enhance the performance of the entire power supply device and reduce the cost. The traction power supply device adopts the technical proposal that the traction power supply device comprises a diode rectification set (1), and is characterized in that a PWM rectification set (5) and a central control unit are also arranged, wherein, the diode rectification set and the PWM rectification set are respectively connected at the alternating current side and the direct current side, so as to form parallel relationship; the central control unit calculates the given values of a d shaft current and a q shaft current of each PWM rectifier unit in the PWM rectification set by detecting the two-phase alternating-current voltage, the two-phase alternating-current and the direct-current output voltage of the diode rectification set, transmits the given values to each PWM rectifier unit in the PWM rectification set through a CAN network and realizes coordination control for the diode rectification set and the PWM rectification set. The invention also discloses a control method of the device.

The power circuit applies the full bridge LC serial connected resonance and the frequency transformer structure to achieve the power transmission. The full bridge LC serial connected resonance converts the power supply of direct current into resonance current, by utilizing the zone current switch. The structure of the high frequency transformer achieves the electric separation and the power transmission. The simple constructed circuit can achieve the power transmit of dual direction, without testing the direction of the output current.

A cooperatively controlled soft switch inverter type dual-wire pulse MIG arc welding power supply is composed of two power supplies for master and slave arc welders, two digitalized coordinate control modules for said arc welding power supplies, and the CAN bus between said two control modules. Said power supply consists of main circuit, external average current closed-loop control circuit and internal peak current closed-loop control circuit. Said external average current closed-loop control circuit comprises current and voltage detecting module, pulse parameters giving up module, comparator, single-chip control system, phase-shift PWM module and HF driver module.

The invention relates to a magnet isolation drive circuit which is applied to a power switch tube of a power supply switch, in particular to the magnet isolation drive circuit which is applied to a silicon carbide power metal oxide semiconductor (MOS) tube. The magnet isolation drive circuit comprises a control circuit, a first capacity C1, an isolation driver transformer T1, a second capacity C2, a light emitting diode D1, a drive pulse amplifying circuit which is connected to the light emitting diode D1 in parallel, a voltage-regulator tube ZD1, a capacity C3 which is connected to the voltage-regulator tube ZD1 in parallel, a resistance R1 and a drive resistance Rg. The magnet isolation drive circuit effectively avoids leakage inductance of a side edge of a transformer T1 on a switch tube, reduces a drive voltage peak value, reduces possibility of breaking down the switch tube, is high in current driving capacity and improves switching frequency of the switch tube. A drive pulse possesses a negative voltage, is capable of effectively preventing from being misled by the drive switch tube and improves work stability of a power supply. The magnet isolation drive circuit is suitable for various duty ratio signals, is simple in structure and low in cost and is particularly capable of fully expressing a performance advantage of the silicon carbide MOS tube.

The invention discloses a photovoltaic grid-connected three-level inverter, and relates to equipment which is used for converting irreversible direct-current power input of a semiconductor device with a control grid into alternating current power output and is used together with a power supply system of a power supply. The inverter consists of a photovoltaic array module, six identical switching tubes, two identical diodes, two groups of identical capacitors, two identical inductors and a power grid. The photovoltaic grid-connected three-level inverter does not generate common mode current, has low differential mode voltage, low current ripple and high efficiency, and overcomes the defect that the three-level inverter needs direct-current input voltage which is about two times that of a full-bridge inverter in the prior art.

A power supply that performs output PWM control and PSM control. The PWM control is performed when the required output is such that a control signal is set with a larger ON pulse width than a predetermined narrow pulse width allowing for sufficient activation of switching elements in an inverter circuit and an auxiliary switching circuit. The PSM control is performed when the required output is such that the control signal for each switching element is set with a smaller ON pulse width than the predetermined narrow pulse width. The PSM control adjusts the phase of a control pulse signal so that the ON pulse is fixed to the predetermined narrow pulse width.

The invention relates to the field of electric and electronic inverter, and discloses a tri-level zero-current conversion soft switching inverter of active middle voltage clamp. The invention comprises a DC side positive pole, a DC side negative pole and a zero level; a first filtering capacitor is connected between the DC side positive pole and the zero level, and a second filtering capacitor isconnected between the negative pole and the zero level; each phase bridge arm comprises a first switching element, a second switching element, a third switching element, a fourth switching element, afifth switching element and a sixth switching element, wherein the first, the second, the third and the fourth elements are sequentially connected in series, the fifth switching element is connected between the shared node of the first and the second switching elements and the zero level, and the sixth switching element is connected between the of the third and the fourth switching elements and the zero level. The invention is characterized in that auxiliary switching elements and auxiliary diodes are connected between the shared node of the first and second switching elements and the shared node of the third and the fourth switching elements to form an auxiliary series connection circuit; a resonant capacitor and a resonant inductor which are sequentially connected in series are connectedbetween the shared node of the auxiliary switching elements and auxiliary diodes and the shared node of the second and the third switching elements.

A power converter provides constant load power while achieving a high power factor in a single stage configuration with reduced component count and ratings. The power converter takes a rectified line input to a switching half-bridge that supplies current to a load. A series combination of shunt switch and capacitor is connected across the load to store energy from the input and supply energy to the load. The switches are operated with conduction angles that achieve constant power supplied to the load while drawing a sinusoidal current in phase with the input voltage to achieve high power factor. The circuit provides a simplified configuration over prior power converters that may be used with a resonant load as part of an electronic ballast or an AC-to-DC converter. The power converter configuration and operation also achieves a low total harmonic distortion on the input line power.

A DC to AC inverter has a DC power input port, a buck converter, a buck/boost converter, an output filter and an AC output port. The DC power input port has a positive input terminal and a negative input terminal, both connected to a DC source. The AC output port is connected to a single-phase utility system. When the single-phase utility system is in positive half cycle, the buck converter generates a positive half-cycle signal of sinusoidal current. When the single-phase utility system is in negative half cycle, the buck/boost converter generates a negative half-cycle signal of sinusoidal current. In either the positive or negative half cycles, only one power electronic switch is switched in high frequency to reduce switching loss. Further, the negative input terminal of the DC power input port of the invention can be connected to a neutral line of the single-phase utility system.

The embodiment of the invention discloses an inverting device and a solar PV (Photovoltaic) grid-connected system applying the same, relates to the technical field of solar PV power generation, and solves the problems that in the existing inverting device, the energy consumption of a boosted circuit is higher, and the switching loss of an inverter is higher. In the embodiment of the invention, when the voltage of a direct-current power supply which is used for supplying power for the inverting device is lower, direct-current electricity can be simultaneously and directly supplied for the inverter in the inverting device through the boosted circuit and the direct-current power supply, thus the inverter can work in an inverting mode of three electric levels, not only can the energy consumption of the boosted circuit be reduced, but also the switching loss of the inverter can be reduced, and the efficiency of the whole system can be obviously increased when the inverting device is applied to a solar PV grid-connected system.

The invention discloses a harmonic current fractional frequency staggered compensation device and a harmonic current fractional frequency giving algorithm thereof. An active part of a main circuit of the device consists of a low-switching-frequency high-power inverter circuit unit and a high-switching-frequency low-power inverter circuit unit, wherein the low-switching-frequency high-power inverter circuit unit and the high-switching-frequency low-power inverter circuit unit are respectively responsible for generating low-frequency components and high-frequency components in harmonic reference current. The two inverter circuit units of the harmonic current compensation device share the same direct-current bus capacitor Cdc, and alternating-current sides of the two inverter circuit units are respectively and serially connected with a seventh serial harmonic branch circuit and a thirteenth serial harmonic branch circuit, then are connected with a filter capacitor and finally are connected to a power grid. A passive part formed by the serial harmonic branch circuits greatly reduces the power level of the active part. The separate giving of the reference current low-frequency components and high-frequency components is realized by adopting the harmonic current fractional frequency giving algorithm based on sliding DFT (Discrete Fourier Transform). The device effectively solves the contradictory constraint relationship among the active part components, the efficiency, the switching frequency and the compensation performance of the harmonic compensation device.

The invention discloses a wind power generation system based on a reverse loose matrix converter and a method thereof, and the structure of the wind power generation system based on the reverse loose matrix converter is as follows: the alternating current side of a rectifier stage is connected with a power grid, the direct current side of the rectifier stage is in butt joint with the direct current side of an inverter stage, the alternating current side of the inverter stage is connected with the output end of a permanent magnet synchronous generator, and the permanent magnet synchronous generator is connected with a fan; the input side of an active protection circuit is connected with the direct current side of an inverter, and the output side of the active protection circuit is connected with the alternating current side of the rectifier stage; the rectifier stage is a three-phase rectifier stage formed by six power device components, and each power device component is formed by connecting a controllable semiconductor power switch with a power diode in series; and the inverter stage is a three-phase bridge type inverter formed by six IGBTs (insulated gate bipolar transistors). The wind power generation system based on the reverse loose matrix converter can convert and transmit energy in a green, high-efficient and reliable manner, and simultaneously ensure the simple and compact structure and the low cost of the system.

A DC-to-DC converter includes two or more inductors coupled to a common core and two or more active switches, where at least one active switch is in an input current path. A controller operates the two or more active switches such that a DC input is driven through one or more of the two or more inductors to implement a power conversion operation.

Disclosed are semiconductor die packages having overlapping dice, systems that use such packages, and methods of making such packages. An exemplary die package comprises a leadframe, a first semiconductor die, and a second semiconductor die that has a recessed portion in one of its surfaces. The first die is disposed over a first portion of the leadframe, and the second die is disposed over a second portion of the leadframe with its recess portion overlying at least a portion of the first die. Another exemplary die package comprises a leadframe with a recessed area, a first semiconductor die disposed in the recessed area, and a second semiconductor die overlying at least a portion of the first die. Preferably, electrically conductive regions of both dice are electrically coupled to a conductive region of the leadframe to provide an interconnection between dice that has very low parasitic capacitance and inductance.

The invention discloses a single-phase PWM rectifier for a railway AC/DC/AC standby power supply. The single-phase PWM rectifier comprises network voltages and an input filter unit which is electrically connected with the network voltages. The network voltages are electrically connected with a rectification unit through the input filter unit. The rectification unit is electrically connected with a DC voltage supporting unit connected with a load. The rectification unit comprises two switch power machines which are connected in series. The two switch power machines which are connected in series are connected in parallel with the input filter unit. The DC voltage supporting unit comprises two sets of positive voltage capacitors which are connected in parallel and then are connected in series. The two sets of positive voltage capacitors are connected in parallel to the rectification unit. A novel single-phase PWM rectifier topological structure is provided, and under the situation that a middle point control algorithm is not added into an inversion side, DC bus middle point potential balance can still be kept. In addition, the structure has the advantages of being simple, reliable, low in switch loss, high in power factor and stable in DC voltage, and idle exchanging is lowered.

The invention discloses a phase-shift full-bridge converter circuit which comprises a transformer, a lead bridge arm, a lag bridge arm and an output circuit. The lead bridge arm is formed by serially connecting a first MOS tube and a second MOS tube, the connection point of the two MOS tubes is sequentially connected with one end of a primary side of the transformer through a capacitor and a resonant inductor, and the capacitor and the resonant inductor are connected in series. The lag bridge arm is formed by serially connecting a third MOS tube and a fourth MOS tube, the connection point of the two MOS tubes is connected with the other end of the primary side of the transformer, and input direct-current voltage is applied to the positions between the connection point of the first MOS tube and the second MOS tube and the connection point of the third MOS tube and the fourth MOS tube. The output circuit is composed of four rectifier diodes and an output capacitor. The voltage of the two ends of the output capacitor is output direct-current voltage. The invention further discloses a control method of the phase-shift full-bridge converter circuit. By means of the circuit and the method, full-bridge soft switching of the phase-shift full-bridge converter circuit is achieved, switching loss is reduced, and efficiency is improved.

The invention relates to a multi-level converter submodule as well as an inverter circuit and an MMC topology both manufactured from such a submodule. The multi-level converter submodule comprises a left branch, a right branch and a capacitor; the left branch comprises 2 IGBT elements, namely a first IGBT element and a second IGBT element; the right branch comprises 2 SiC-MOSFET elements, namely a first SiC-MOSFET element and a second SiC-MOSFET element; the first first IGBT element, the second IGBT element, the first SiC-MOSFET element and the second SiC-MOSFET element are orderly bridged together; the anode of the capacitor is connected with a common point between the first IGBT element and the first SiC-MOSFET element, while the cathode of the capacitor is connected with a common point between the IGBT element and the second SiC-MOSFET element. The IGBT and SiC-MOSFET mixed full-bridge submodule is adopted to break through the restriction on the switching frequency caused by the Si material, and therefore, the switching frequency of the MMC-HVDC system is comprehensively improved.

The invention discloses a segmented resistance type IGBT driving circuit, which is characterized in that a segmented resistor driving circuit comprises a plurality of segmented resistors which are connected in series, both ends of each segmented resistors are connected with a bypass MOS transistor in parallel; each bypass MOS transistor and a driving push-pull circuit are connected with a driving controller; and an IGBT gate clamping circuit comprises an IGBT gate voltage-stabilized clamping circuit and an IGBT gate power supply clamping circuit. The invention further discloses a control method of the segmented resistance type IGBT driving circuit, which is characterized in that a pulse rising edge and a falling edge are driven at the gate, and the size of the gate driving resistance is changed through switching of the bypass MOS transistors. The segmented resistance type IGBT driving circuit and the control method thereof can achieve the purposes of reducing the switching loss of an IGBT device and improving the application frequency of the device while ensuring suppression for surge and gate oscillation.

The invention discloses an inductor-capacitor quasi-resonance-based equalization circuit. The equalization circuit comprises a battery pack and an inductor-capacitor quasi-resonance unit and also comprises a gating switch network and a master controller, wherein the gating switch network is connected with a battery pack and the inductor-capacitor quasi-resonance unit; and during the equalization process, the master controller controls the gating switch network and the inductor-capacitor quasi-resonance unit so that the inductor-capacitor quasi-resonance unit is switched in states of charging, discharge and resonance in a circulation way, and a battery with highest energy transfers the energy to a battery with lowest energy through an inductor-capacitor. By the equalization circuit, zero-current switching of a switch can be achieved, zero-voltage differential equalization among batteries is achieved, and the technical effect of higher speed than that of an existing quasi-resonance circuit is achieved. By the equalization circuit, the switch loss of a switch device can be greatly reduced, and the equalization circuit has the advantages of a few energy storage devices, small circuit size and fast equalization speed, and is applicable to a battery management system of an energy storage device in an electric vehicle or an energy storage power station.

A power conversion device able to supply a constant load voltage even when the voltage of a 3-phase alternating current power supply fluctuates. A series circuit formed of switching element Q1 and switching element Q2 and a series circuit formed of switching element Q3 and switching element Q4 are connected to both ends of direct current power supply series circuit 3 formed of direct current power supply Psp and direct current power supply Psn, a bidirectional switch element S1 is connected between alternating current output terminals U and R, a bidirectional switch element S2 is connected between alternating current output terminal U and neutral terminal O, a bidirectional switch element S3 is connected between alternating current output terminal W and neutral terminal O, a bidirectional switch element S4 is connected between alternating current output terminal W and terminal T, and alternating current output terminals V and terminal S are connected.

A switching power supply circuit includes: a reactor that has a main winding and an auxiliary winding having a leakage inductance, which are magnetically coupled with each other and are connected with each other at one ends thereof; a first series circuit, which has an auxiliary switch and a resonance capacitor connected in series, and which is connected in parallel with a direct current power supply via a main switch; a first diode that, which is connected in parallel with the first series circuit via the auxiliary winding; a smoothing capacitor, which is connected in parallel with at least one of the first series circuit and first diode via the main winding; and a control circuit, which alternately turns on and off the main switch and auxiliary switch to thus control an output voltage of the smoothing capacitor to be a predetermined value.

The invention discloses a solar photovoltaic charge control device. A PWM signal drive component (6) comprises an RC low pass filter (61), a PWM chip (62) and a logic gate circuit (63) which are connected in series, and is used for providing drive signals of an auxiliary switch (31), a main switch (32) and a synchronous rectification switch (33) to a DC-DC conversion component (3) in time sequence according to PWM duty ratio signals of a microprocessor (5). The DC-DC conversion component (3) is composed of the main switch (32) with the two ends being connected with first resonance capacitors (C1) in parallel, the synchronous rectification switch (33) with the two ends being connected with second resonance capacitors (C2) in parallel, the auxiliary switch (31), a resonance inductor (Lr) and a filter inductor (Lf). The DC-DC conversion component (3) is used for sequentially enabling the synchronous rectification switch (33) to be turned off with zero current, the main switch (32) to be turned on with zero voltage and then turned off with quasi zero voltage according to set time of duty ratio, and the synchronous rectification switch (33) to be turned on with zero voltage and drop voltage of the synchronous rectification switch (33) at a steady state by not higher than 0.1 V. The solar photovoltaic charge control device can be widely applied to high-power photovoltaic electricity generation systems.

The invention discloses a circuit with an active power decoupling single-phase no-voltage switch inverter and a modulation method thereof. The circuit comprises a direct-current power supply, three groups of bridge arms, a filter inductor of the inverter and a power grid, a filter inductor and an energy-storage capacitor decoupled by active power, an auxiliary switch comprising an anti-parallel diode connected between the direct-current power supply and a bus of the three groups of bridge arms, a resonance branch circuit consisting of a clamping resistor and a resonance inductor, and a capacitor, wherein the three groups of bridge arms comprise two groups of full-bridge single-phase inverters and an active power decoupling group, and each group of bridge arms is composed of two full control type switches with anti-parallel diodes; and the main switch is connected with two ends of the auxiliary switch in parallel. According to the modulation method, pulse signals of the auxiliary switchand the main switch are synchronized, no-voltage switching-on of all switches can be realized in each switching period, the reverse recovery current of the anti-parallel diode of the main switch is effectively inhibited, the switching loss is little, the circuit efficiency is high, the switching efficiency is improved, and the system power density is improved.