36results about How to "Small current ripple" patented technology

The invention provides a control method applied to a bidirectional isolation full-bridge current transformer for battery energy storage, and aims at the current-voltage type bidirectional isolation full-bridge current transformer, a current-mode full bridge is connected at a battery side, and a voltage-mode full bridge is connected at an inverter side. According to pulse generation method of two H-bridges, the control of the bidirectional isolation full-bridge current transformer becomes simple. A current-mode H-bridge utilizes PWM (pulse-width modulation) to guarantee the current continuity of input inductance and control the transitive power; and a voltage-mode H-bridge utilizes phase shift control to match and finish the bidirectional flow of power. Phase shift between carriers of an original secondary side H-bridge is controlled, so that the power of the bidirectional isolation full-bridge current transformer is only related to the current-mode PWM duty cycle, and power control of the bidirectional isolation full-bridge current transformer can be finished only by using a single PI ring. The control method provided by the invention is simple and practical, and lays a basis for the application of the bidirectional isolation full-bridge current transformer in battery energy storage.

The invention relates to a disc-type coreless permanent-magnet synchronous motor controller based on a current inverter and a method. The disc-type coreless permanent-magnet synchronous motor controller comprises a control circuit, a three-phase inverting circuit and a step-down chopper circuit, wherein the three-phase inverting circuit is used for driving a disc-type coreless motor, and the signal input end of the three-phase inverting circuit is connected with the signal output end of the control circuit; the control signal input end of the step-down chopper circuit is connected with the signal output end of the control circuit, and the current output end of the step-down chopper circuit is connected with the current input end of the three-phase inverting circuit through an inductor L; the output shaft of the disc-type coreless motor is connected with the signal input end of the control circuit through an angle sensor; and the three-phase current outputs of the three-phase inverting circuit are respectively connected with the signal input end of the control circuit through a current sensor. The controller controls the speed regulation of the disc-type coreless permanent-magnet synchronous motor and increases the maximum speed of the motor. The controller has the characteristics of small current pulsation, good sinusoidal performance, convenience in energy feedback and the like.

The invention discloses a wide-voltage-input efficient direct-current power converter for an aerostat. The wide-voltage-input efficient direct-current power converter comprises a SuperBuck circuit, a push-pull circuit, a closed-loop control circuit and a diode used for achieving the series connection of the output end of the SuperBuck circuit and the output end of the push-pull circuit, wherein the SuperBuck circuit is composed of an inductor, a capacitor, a diode and a switch tube, and the push-pull circuit is composed of a switch tube, a boosting transformer, a rectifier diode and a filter capacitor. The wide-voltage-input efficient direct-current power converter for the aerostat has the advantages that the polarity of input voltages and the polarity of output voltages are identical, a main circuit device is simple, input currents and output currents are consecutive, input and output are common-grounded, current pulses caused to a power supply bus and a storage battery are small, and smooth switching of voltage boosting and voltage reduction can be achieved.

The invention discloses a controller for a digitalized proportional valve with high switching frequency. The controller comprises a microprocessor, a communication port, a drive circuit, a power amplification circuit, a position detection circuit and a circuit detection circuit. The communication port is connected with the microprocessor in a bidirectional communication mode, the position detection circuit and the current detection circuit are connected with analog-digital conversion interfaces of the microprocessor respectively, the microprocessor is connected with the power amplification circuit through the drive circuit, and the power amplification circuit is in electric connection with an electromagnetic coil of the proportional valve. The invention further discloses a control method of the controller for the digitalized proportional valve with high switching frequency. The method comprises the steps that the microprocessor receives a position setting signal and a current setting signal through the communication port, and whether position closed-loop control and current closed-loop control or only the current closed-loop control is adopted in the controller for the proportional valve is judged through a selection switch. By means of the control method, the working modes can be selected according to the actual working demands, and good flexibility and adaptability are achieved.

The invention relates to a stepless speed regulation device for a working table or a spindle of a numerical control machine tool. The device comprises a speed regulator, a current regulator, a triangular wave generator, a pulse width modem, a transistor amplification circuit, a current signal amplifier and a speed measurement feedback circuit. The speed regulator, the current regulator, the pulse width modem and the transistor amplification circuit are connected sequentially. The triangular wave generator is connected with the pulse width modem, the input end of the current signal amplifier is connected with the output end of the transistor amplification circuit, the input end of the current signal amplifier is connected with the input end of the current regulator, and the speed measurement feedback circuit for measuring the rotation speed of a motor is connected with the input end of the speed regulator. The device has the advantages that the bandwidth is wide, and the frequency is high; the transistor 'junction capacitance' is small, and the rapidity is good; the current pulsation is small, and the power factor of a power supply is high; a direct-current power supply of a PWM system is uncontrolled rectification output, the power factor is good, and the dynamic hardness is good.

The invention relates to an insulated gate bipolar translator (IGBT) clamping three-level frequency converter, and belongs to the field of frequency converters. A main circuit of the IGBT clamping three-level frequency converter is a three-phase six-bridge arm frequency converting circuit; each of a first bridge arm, a second bridge arm, a third bridge arm, a fourth bridge arm, a fifth bridge arm and a sixth bridge arm comprises three switching elements, wherein the first bridge arm and the second bridge arm are connected with a phase W of an output circuit; the third bridge arm and the fourth bridge arm are connected with a phase V of the output circuit; the fifth bridge arm and the sixth bridge arm are connected with a phase U of the output circuit; and each of the phase W, the phase V and the phase U is provided with six free-wheeling diodes and two series energy storage capacitors. By clamping connection and disconnection of an IGBT, the frequency converter solves the problem that the waveform quality of the output voltage is affected by unequal upper and lower capacitor voltages and midpoint potential drift when a certain phase of output voltage in three phases of output voltages is zero, current flows into or flows out of a direct-current capacitor midpoint and the inflow current is unequal to the outflow current.

The invention provides a synchronous switched reluctance motor, mainly comprising a three-phase stator, a salient pole rotor, a rotor position sensor, a casing, a motor controller and a shaft, whereinthe three-phase stator adopts a three-phase concentrated winding or a three-phase distributed winding and generates a synchronous rotating magnetic field under the driving control of the motor controller, and the strength and rotating speed of the synchronous rotating magnetic field can be controlled by the motor controller through the three-phase stator; the salient pole rotor does not include apermanent magnet or a squirrel cage structure, does not need to open a reluctance groove, is formed by laminating only silicon steel sheets and has an even number of salient poles; the three-phase stator is mounted inside the casing, the salient pole rotor is mounted on the shaft and mounted on the casing through the shaft, and the rotor position sensor is mounted at one end of the shaft; and thethree-phase stator and the salient pole rotor constitute a radial magnetic circuit. The novel synchronous switched reluctance motor not only retains the advantages of simple structure of a switched reluctance motor and the advantages of small torque ripple and low noise of a synchronous reluctance motor, but also overcomes the large torque ripple of the switched reluctance motor and the complicated structure of the synchronous reluctance motor.

The invention relates to an alternative-boost-buck-circuit-based voltage equalizer comprising a direct-current link, a bidirectional alternative boost-buck converter, an output filter circuit and a load. A positive terminal and a negative terminal of the bidirectional alternative boost-buck converter are respectively hooked to a positive potential link and a negative potential link of the direct-current link and a common terminal of the bidirectional alternative boost-buck converter and a capacitance common terminal of the output filter circuit are connected to form a neutral line, thereby forming a dual-polarity bus distribution mode. According to the voltage equalizer provided by the invention, with the alternative control technology, the power level can be increased conveniently and the current pulse of the direct-current link can be effectively reduced, thereby reducing the decoupling capacitance of the direct-current link. Meanwhile, currents flowing through the neutral point almost have no pulsation, so that the filter capacitance can be substantially reduced. The alternative-boost-buck-circuit-based voltage equalizer is suitable for a distribution system of a direct-current micrgrid as well as a bipolar bus distribution power supply system on a ship or a plane, especially for an aerospace direct-current distribution system with a strict size requirement.

The invention belongs to the technical field of power supply of power sources, and provides a positive and negative output DC-DC power source structure based on Boost. The structure comprises a Boostconversion structure, and the Boost conversion structure comprises an input direct current power source Vin, an inductor L1, a diode D1, a switching tube Q1 and an energy storage filter capacitor C2;a capacitor C1 and a diode D2 which are in series connection with each other are inserted into a switching node between the inductor L1 and the diode D1, and a diode D3, an inductor L2 and an energy storage filter capacitor C3 which are in series connection are connected into a series-connection node of the capacitor C1 and the diode D2, and two output ends of negative voltage are draw forth fromthe two ends of the energy storage filter capacitor C3; a negative electrode of the diode D3 is connected with the capacitor C1, a positive electrode of the diode D2 is connected with the capacitor C1, and the capacitor C1, the inductor L2 and the energy storage filter capacitor C3 constitute an LC filter circuit. By means of the positive and negative output DC-DC power source structure, a switching tube or a switching control chip does not need to be additionally arranged, the circuit structure is simple, and the cost is low; the structure has a high current output capability and small current pulsation, and the positive voltage and negative voltage are nearly symmetric.

The invention discloses a low-current pulsation duty ratio optimization method for a direct-driven permanent magnet wind driven generator, and the method specifically comprises the steps: collecting the real-time data of a generator, and calculating the reference voltage of a dq axis; according to the reference voltage phase angle, calculating the sector of the reference voltage phase angle; solving a first-order partial derivative of the vector duty ratio to obtain the duty ratios alpha g1 and alpha g2 of two adjacent vectors; when the alpha g1 and the alpha g2 are smaller than 0, the action of the corresponding voltage vector is cancelled, when the alpha g1 and the alpha g2 are larger than 1, the voltage vector with the vector duty ratio larger than 1 acts on the whole period, and when the alpha g1 and the alpha g2 are in the range of [0, 1], the vector duty ratio is redistributed; and the three-phase duty ratio of the generator is redistributed. Generator stator current pulsation can be effectively reduced, and the stability of the system is improved.

The invention discloses a 3300v frequency converter adopting a phase voltage frequency conversion technology. The 3300v frequency converter adopts an input 3300v transformer and comprises a first input circuit, a second input circuit and a third input circuit; the first input circuit is a R-O input circuit; the second input circuit is an S-O input circuit; the third input circuit is a T-O input circuit; a first output circuit, a second output circuit and a third output circuit correspond to the first input circuit, the second input circuit and the third input circuit, respectively. As the rectification and inversion power devices of the frequency converter are arranged according to a special topology structure, the 3300v frequency converter adopting the phase voltage frequency conversion technology obtains an effect of driving a 3300v motor by using a 4500v withstand voltage level IGBT.