Patents
Literature
Hiro is an intelligent assistant for R&D personnel, combined with Patent DNA, to facilitate innovative research.
Hiro

41results about How to "Improve voltage waveform" patented technology

Microgrid inverter multi-loop control method based on virtual synchronous generator

The invention discloses a microgrid inverter multi-loop control method based on a virtual synchronous generator, and the method comprises power control of an outer loop and voltage current control of an inner loop. The power control of the outer loop comprises the following steps: measuring the three-phase voltage and current of an output side of an inverter, calculating active power and reactive power according to the instantaneous power theory, carrying out calculation and regulation through an active power-frequency equation, a reactive frequency equation, a torque inertia equation and an electromagnetic transient equation of a synchronous motor, obtaining the amplitude of an output voltage and a phase angle given value, and then carrying out modulation through voltage and current double loops. The method can achieve the non-corresponding control of voltage size and frequency well, outputs active and reactive power, can achieve precise manual control, and has the characteristics of V / F and PQ control. When a fault happens to a power grid, the method can simulate the primary modulation, primary voltage regulation and inertia characteristics of the synchronous generator, participates in the power grid adjustment, provides frequency and voltage support, and facilitates the stabilization of the power grid.
Owner:SOUTHEAST UNIV

Microgrid reactive power compensation method and system

The invention relates to a reactive power compensation method and a reactive power compensation system for a micro power grid. The system comprises a distributed measuring unit, a reactive power compensation control unit, a reactive power compensation unit and a communication unit. The micro power grid comprises a distributed power supply with reactive regulation output. For the micro power grid operated in an isolated network mode, the overall reactive power balance condition of the micro power grid is obtained by measuring the active and reactive power distribution conditions of each branchcircuit of the micro power grid, and a reactive power compensation device or the reactive power compensation device and the distributed power supply are subjected to reactive regulation in the micro power grid according to a specific isolated network reactive control strategy to realize the reactive power compensation of the micro power grid. The power factor of the micro power grid can be measured and corresponding reactive power compensation is performed according to the power factor when the micro power grid is operated in a grid-connected mode and in the isolated network mode.
Owner:北京四方华能电气设备有限公司

Reactive capacitance compensation cabinet

The invention discloses a reactive capacitance compensation cabinet which comprises a cabinet body, wherein the cabinet body is internally provided with a plurality of three-phase compensation units, a plurality of split phase compensation units, a breaker and a controller; each the three-phase compensation unit comprises three compensation single-phase circuits; the compensation single-phase circuits comprise fuses, reactors, switching switches and capacitors that are electrically connected sequentially; the three compensation single-phase circuits adopt delta connection; each split phase compensation unit comprises three split compensation single-phase circuits; the three split compensation single-phase circuits adopt star connection; the three-phase compensation units and the split phase compensation units are connected with an outside three-phrase power grid by the breaker; the switching switches are connected with the controller; and the controller is connected with a detection unit for detecting current signals and voltage signals of the three-phrase power grid. The compensation cabinet combines three-phase compensation and split phase compensation, and can conduct intelligent switching conversion and automatic combined configuration, and inhibit and filter harmonic waves.
Owner:张家港保税区天翔电气有限公司

Performance testing method for voltage transformer

The invention relates to the field of unit testing of high voltage transformer products, in particular to a performance testing method for the voltage transformer. The performance testing method for the voltage transformer is characterized in that a frequency modulation voltage-controlled power source is used as a testing power source and a frequency-modulated and voltage-controlled voltage signal is output, the requirements for the exciting voltage of a secondary winding of a tested voltage transformer are met through voltage rising of an exciting transformer, the induction voltage of the first winding of the tested voltage transformer is collected by a voltage sampler, and monitoring is conducted on the output voltage, the frequency and the output currents of the frequency-modulation voltage-controlled power source and high-voltage feedback of the voltage transformer. Compared with the prior art, the performance testing method for the voltage transformer has the advantages that a third harmonic generation power source large in size is replaced, conveying cost of testing equipment is reduced, testing quality is improved, voltage waveform is improved, and disturbance of higher harmonics is avoided. During the testing process, the no-load voltage ratio and excitation characteristic testing can be achieved under the power frequency conditions, and the voltage transformer is multifunctional. Over-voltage protection can be set, and the safety of the tested voltage transformer can be ensured. Equipment is low in weight and convenient to carry.
Owner:CHINA THIRD METALLURGICAL GRP

Overall salient type intermediate-frequency brushless excitation synchronous generator

InactiveCN101795040AThe voltage is basically constantStator magnetic field enhancementSynchronous generatorsCooling/ventillation arrangementIntermediate frequencyTransformer
The invention relates to an overall salient type intermediate-frequency brushless excitation synchronous generator, which comprises a main generator, an exciter, an excitation regulating system. The excitation regulating system consists of a compound excitation device, a rotating rectifier and an AVR automatic voltage regulator, wherein the compound excitation device consists of a compound excitation winding, a compound excitation current transformer and a three-phase rectifier bridge, the stator of the main generator adopts a fractional slot type short-range winding, the slot number per pole and per phase q is a fractional value, the rotor of the main generator is formed by lamination of multi-pole rotor core laminated pieces, the rotor core of the main generator is of an overall salient type rotor core structure and is formed by overall punching and lamination of rotor core laminated pieces, each rotor core laminated piece is formed with a magnetic pole and a magnetic yoke integrated, and an axial air-cooling hole is arranged at the magnetic yoke. The generator realizes the brushless excitation intermediate-frequency generation, outputs the single-phase or three-phase intermediate-frequency voltage, and has the advantages of excellent performance, stable and reliable operation and high output power.
Owner:上海强辉电机有限公司

Low-fluctuation rare earth permanent magnetic brushless motor

A low-pulse rare earth permanent magnetism brushless motor comprises a stator and a rotor which forms a column shape by stacking the punched sheet. A radial air gap is arranged between the stator and the rotor. The rotor is uniformly and symmetrically arranged with a permanent magnet accommodating holes. The permanent magnet is inserted in the accommodating hole and the end of the accommodating hole is arranged with magnetism-splitting holes which are symmetrically arranged at two ends of the diagonal of the accommodating hole. The magnetism-splitting hole is larger at the side next to the accommodating hole and gradually reduces along the radian direction of the outer diameter of the rotor and at last forms a small arc. Through arranging a magnetism-splitting hole at the end of the permanent magnet accommodating hole of the punched piece of the rotor and at the same time designing the radial air gap between the stator and the rotor to asymmetric air gap through the different positions of the inner diameter of the stator and the outer diameter of the rotor, the invention has the advantages of endowing the electric motor with magnetism collecting function, evidently improving the voltage waveform induced in the stator winding, namely improving the back electromotive force waveform of the electric motor, reducing the torque of the tooth socket, reducing the torque ripple, and realizing the high-efficiency, smooth and silent operation of the permanent magnet brushless motor.
Owner:GUANGDONG MEIZHI COMPRESSOR

Mechanical energy storage type highway speed bump power generation device

ActiveCN109098940ASimple structureRealize energy storage and power generationSpring motorMachines/enginesSpeed bumpMetal strips
The invention discloses a mechanical energy storage type highway speed bump power generation device comprising a mechanical transmission part and an energy storage power generation part. The mechanical transmission part mainly comprises a speed bump, a supporting frame, a metal strip, a first crank, a second crank and a driving swing rod, wherein the first crank, the second crank and the driving swing rod are sequentially hinged; one end of the first crank is hinged to the metal strip, the other end of the first crank and the second crank are jointly hinged to a sliding block, the sliding block is mounted in a guiding groove in a supporting plate, and a return spring is mounted on the lower portion of the sliding block in the guiding groove; a driving pawl of a ratchet wheel structure andthe driving swing rod are fixed, a rotating shaft is fixedly connected with a first one-way clutch and a second one-way clutch which are opposite in linkage direction, and the outer circle of the first one-way clutch is fixedly connected with a ratchet wheel; the energy storage power generation part comprises a power generator and a spring-type elastic energy storage device, a mounting gear is arranged on a power generator shaft, and the mounting gear is engaged with an external gear at the outer circle of the second one-way clutch. According to the mechanical energy storage type highway speedbump power generation device, the multistage variable speed is set, the high transmission ratio is achieved as much as possible through the smallest space, mounting is convenient, and the power generation amount is large.
Owner:WUHAN UNIV

Power conversion device

A power conversion device includes transformers (20n) provided with primary windings connected to input terminals (R,S,T) and secondary windings including pluralities of single-phase open windings that are insulated from each other; a plurality of converter cells (30Xn) connected to the secondary windings of the transformers (20n); and a control circuit (601) for controlling ON / OFF of switching elements. The converter cells (30Xn) each include a converter (3a) and the inverter (3b) that are provided with the switching elements, in which their input ends are connected to the respective single-phase open windings, so that the input ends are connected in mutually parallel fashion, through the transformers (20n), to the input terminal (R,S,T) of each phase, and in which their output ends are connected in mutually serial fashion to an output terminal (U,V,W) of each phase, to thereby perform three or more-level power conversion.
Owner:TOSHIBA MITSUBISHI-ELECTRIC IND SYST CORP

Novel voltage stabilizer filtering topology and filtering control method

The invention provides an AC chopper-type voltage stabilizer, a filtering method and a filtering system thereof. The voltage stabilizer comprises a two-way switch buck converter, a filter circuit, a transformer and a control unit, wherein the control unit treats the actual input voltage Vm of the voltage stabilizer according to the following filtering method, generates and sends control signals to the two-way switch buck converter, and controls the output waveform of the voltage stabilizer by controlling the turn-on and turn-off of a power switching element. The filtering method at least comprises: (1) performing band-stop filtering on the actual input voltage Vm of the voltage stabilizer and generating a signal Vs1; (2) implementing linear correction and generating a signal Vs2; (3) performing division algorithm and generating a signal Vc; (4) performing negative feedback operation and generating a signal Vs3; and (5) forming a PWM control signal. Through hardware and software filtering, the invention has the advantages of improving filter topology, adding a filtering control method and ensuring good voltage waveform on the primary side of the transformer, good voltage compensation effect of the transformer and superior performance of the voltage stabilizer.
Owner:北京博旺天成科技发展有限公司

Multi-level reactive compensation system suitable for unbalanced load and control method of multi-level reactive compensation system

The invention relates to a multi-level reactive compensation system suitable for an unbalanced load and a control method of the multi-level reactive compensation system and belongs to the field of thereactive compensation of electric power systems. According to the multi-level reactive compensation system, a convection circuit includes a direct current link and an inversion circuit which are connected in parallel; the direct current link comprises a plurality of direct current link circuit units which are connected in series; each direct current link unit comprises a switching tube S1, a switching tube S2 and a capacitor C1; the positive pole of the capacitor C1 is connected with the collector of the switching tube S1; the emitter of the switching tube S1 is connected with the collector of the switching tube S2; and the emitter of the switching tube S2 is connected with the negative pole of the capacitor C1. The number of switches and the number of grid drivers can be remarkably reduced compared with a cascade H-bridge structure, therefore, the system is easier to expand, and can effectively inhibit and eliminate harmonic waves in a reactive current compensation process.
Owner:HARBIN UNIV OF SCI & TECH

Connecting method of non-60-degree phase belt symmetric windings

The invention discloses a slot number selection, phase belt division and winding connection method of non-60-degree phase belt symmetric double-layer stator windings. According to the method, the pole number, the branch number, the relation between the slot number of each phase and each pole, the phase belt division and the specific requirement, it is pointed that the non-60-degree phase belt symmetric double-layer stator windings can be wave windings or lap windings, and can be integral-slot windings or fractional-slot windings, and the windings must be connected in a whole-distance mode. The problem that the capacity, the rotating speed and voltage are mismatched can be solved, and the aims that the harmonic wave is weakened, and the voltage waveform is improved can be achieved.
Owner:DONGFANG ELECTRIC MACHINERY

Transformer with zero sequence filtering function

The invention relates to a transformer, particularly to a transformer used for an AC power supply and provided with a zero sequence wave filtering function, and provides a transformer of a zero sequence wave filter, which is provided with an amorphous power transformer and capable of filtering zero sequence wave. The invention can greatly reduce the dead time loss of a distribution transformer so as to energy resource, and can filter zero sequence wave. The invention comprises a transformer which is an amorphous power transformer. A pure sensing zero sequence wave filter is connected to the amorphous power transformer and comprises a linear reactance and a wave filtering reactance. The invention not only can greatly reduce the dead time loss of the distribution transformer, thereby saving energy source, but also provides a simple and efficient technical proposal which can solve the zero sequence harmonic current problem and generate no interference for an AC power grid, where the transformer is installed.
Owner:QINGDAO YUNLU ENERGY TECH

Stand-by power supply on-line device

The invention relates to a stand-by power supply on-line device, which comprises two voltage source current converters, and a direct current short bus and a direct current capacitor which are connected between the two voltage source current converters, wherein each voltage source current converter comprises a converter transformer, a converter reactor, a voltage source converter valve and a controller thereof. According to the stand-by power supply on-line device, short circuit fault penetration between a work power supply and a stand-by power supply can be isolated, the online operation mode of the stand-by power supply is realized at the same time, the power interchange between the work power supply and the stand-by power supply is realized, the continuous power supply function in a switch process of the user work power supply and the stand-by power supply is realized, the supply voltage quality is effectively improved, the satisfaction of a user on the voltage quality is improved, and in addition, the stand-by power supply on-line device also has the functions that the bus power factor is improved, the bus voltage waveform is improved, the bus voltage is stabilized, voltage sag is restrained and the like.
Owner:BEIJING HUAAN YUANDA INTELLIGENT ELECTRICAL CO LTD

Series voltage injection-based current-type high voltage direct current transmission (HVDC) system commutation failure suppression method

The invention discloses a series voltage injection-based current-type high voltage direct current transmission (LCC-HVDC) system commutation failure suppression method. The core of the method is thatthree-phase voltage series injection is carried out between the inverter of the LCC-HVDC and a receiving-end AC system to compensate dynamic fall of the voltage of the receiving-end AC system, seriesvoltage injection is realized through a unified power flow controller, a parallel transformer of the unified power flow controller is parallelly connected at the AC system side, and a series transformer is serially connected at the inverter side of the LCC-HVDC. A dynamic voltage series injection control algorithm is designed for the series converter of the unified power flow controller, so as toenable the three-phase voltage generated by the series converter of the unified power flow controller to dynamically compensate the dynamic fall of the voltage at the AC system side through the seriestransformer. Voltage distortion and voltage fall at the LCC-HVDC inverter side can be further reduced, and finally, the LCC-HVDC inverter commutation failure possibility is reduced.
Owner:SOUTH CHINA UNIV OF TECH

Multi-loop control method of microgrid inverter based on virtual synchronous generator

The invention discloses a microgrid inverter multi-loop control method based on a virtual synchronous generator, and the method comprises power control of an outer loop and voltage current control of an inner loop. The power control of the outer loop comprises the following steps: measuring the three-phase voltage and current of an output side of an inverter, calculating active power and reactive power according to the instantaneous power theory, carrying out calculation and regulation through an active power-frequency equation, a reactive frequency equation, a torque inertia equation and an electromagnetic transient equation of a synchronous motor, obtaining the amplitude of an output voltage and a phase angle given value, and then carrying out modulation through voltage and current double loops. The method can achieve the non-corresponding control of voltage size and frequency well, outputs active and reactive power, can achieve precise manual control, and has the characteristics of V / F and PQ control. When a fault happens to a power grid, the method can simulate the primary modulation, primary voltage regulation and inertia characteristics of the synchronous generator, participates in the power grid adjustment, provides frequency and voltage support, and facilitates the stabilization of the power grid.
Owner:SOUTHEAST UNIV

Asymmetric connecting wire balancing transformer and implementation method thereof

The invention discloses an asymmetric connecting wire balancing transformer and an implementation method thereof. The transformer comprises an iron core, a primary side winding and a secondary side winding, and is characterized in that: the primary side winding adopts a Y-shaped connecting wire; a neural point N of the Y-shaped connecting wire is grounded; the number of circles of the primary side winding is W1; in the secondary side winding, the A-phase winding consists of two windings, namely ea and ab; the B-phase winding consists of one winding bc; and the C-phase winding consists of two windings, namely dc and ca; the number of circles of the windings ab, bc, ca and dc is W2, and the number of circles of the winding ea is W3; the windings ab, ca and ea are connected with one another at a point a serving as a common point, the windings ca, bc and dc are connected with one another at a point c serving as another common point, and the windings ab and bc are connected with each other at a point b serving as another common point; two no-load voltages Ueb and Udb are equal to each other; and the phase difference is 90 degrees. The secondary side of the asymmetric connecting wire balancing transformer has an asymmetric winding structure, so the production is convenient to execute, the comprehensive performance is high, the structure is simple, and the material utilization rate is high.
Owner:HUNAN UNIV +2

Three-phase lap winding having fractional slot and fractional turn

Characters of the invention are that equidistant pile windings are adopted in three-phase a.c. winding, where number of slots for each phase and each pole is a fraction, and mean turn is a fraction. Advantages are: optimizing winding, good waveform of voltage, small regulation rate for transient voltage, small harmonic wave of magnetic potential and electric potential, and easy of controlling waveform deviation factor of phase voltage under 2%.
Owner:TELLHOW SCI TECH CO LTD

Smoothing reactor end-to-end capacitor discharge test system and transient wave trapper thereof

InactiveCN104215886AGuaranteed validityDoes not significantly affect the main oscillation timeTesting dielectric strengthOverload protection arrangementsTransient stateCapacitance
The invention provides a smoothing reactor end-to-end capacitor discharge test system and a transient wave trapper thereof. The transient wave trapper comprises a first resistor, a second resistor, a third resistor, a first capacitor and a second capacitor, one end of the first resistor is connected to one end of the second resistor and one end of the third resistor, the other end of the second resistor is grounded, the other end of the third resistor is connected to one end of the first capacitor and one end of the second capacitor, and the other end of the first capacitor and the other end of the second capacitor are grounded.
Owner:BEIJING POWER EQUIP GRP

Permanent-magnet synchronous motor

A permanent-magnetism sychronous motor features that the rotator of the main motor is structured by two parts such as a permanent magnet being set up on one part and a DC excitation winding set up onanother part, its punched sheet being formed by punching with soft iron plate and being equipped with damping cage built by copper conductor; the stator armature of the main motor is designed into a per sine winding with harmonic winding. An auxiliary motor is a AC exciter. The motor is brushless and can be used either as a synchronous generator or as a motor.
Owner:TELLHOW SCI TECH CO LTD

A bulb tubular hydroelectric generator

The invention provides a bulb tubular hydraulic generator, and belongs to the technical field of hydroelectric power generation equipment. The bulb tubular hydraulic generator comprises a bulb head and a stator frame integrally fixed and arranged in a co-movable manner, a generator body fixed in the stator frame, a stator upstream flange clamped between the stator frame and the bulb had, at least a group of ventilation assembly, and at least one group of wind screen assembly, a plurality of ventilation assemblies are fixed on the stator upstream flange and uniformly distributed at intervals in a co-circumferential manner, the wind screen assemblies are detachably fixed in the stator frame, the wind screen assemblies and the stator upstream flange are constructed to form a single-circulation air supply unit in which the wind screen assemblies communicate with the ventilation assemblies and the wind screen assemblies and the ventilation assemblies are mutually independent, the generator body comprises excitation assemblies, and the excitation assemblies and the stator frame are arranged in a coaxial manner. According to the bulb tubular hydraulic generator, brushless double-frequency generation can be realized, brushless variable-frequency generation can also be realized, the energy consumption of the whole ventilation system is reduced, the axial air quantity distribution can be effectively improved, and the ventilation and heat radiation effects of a unit can be improved.
Owner:湖南云箭集团有限公司

Harmonic suppression circuit for electromagnetic compatibility laboratory and compensation method thereof

The invention belongs to the technical field of harmonic treatment, and provides a harmonic suppression circuit for an electromagnetic compatibility laboratory and a compensation method thereof. The circuit and the method thereof adopt two-stage tandem type active power filters connected in series in the forward direction, and a dry-type iron core reactor is connected in parallel between the tandem type active power filters and the power source end of a load. The dry-type iron core reactor is mainly used for restraining high-frequency interference with a frequency higher than 10 KHz, cannot influence the filter performance of the tandem type active power filters, is the major support equipment of a reactive compensation device in an electric system, can effectively restrain higher harmonic, limits the switching-on flashy current and switching overvoltage, improves the voltage waveform of the system, increases the power factor, and plays a greater function for the safe operation of a power capacitor and other electric equipment. Therefore, the dry-type iron core reactor connected in parallel connection guarantees the safe operation of other equipment in the electromagnetic compatibility laboratory, voltage change of inlets of all loads can be compensated, the detection reliability and accuracy in electromagnetic compatibility of the product can be improved.
Owner:潘奇 +4

An Electronic Ballast for Reducing Grid Voltage Waveform Distortion Through Triac

The invention discloses an electronic-type ballast for reducing the power grid voltage waveform distortion by bidirectional controllable silicon. The electronic-type ballast for reducing the power grid voltage waveform distortion by bidirectional controllable silicon comprises a rectifying circuit, a filter circuit, a contravariant driving circuit and a contravariant circuit. The electronic-type ballast for reducing the power grid voltage waveform distortion by bidirectional controllable silicon is characterized in that an input end of the rectifying circuit is provided with an electronic switch circuit; the electronic switch circuit is always at a disconnection state in the process that the power grid voltage changes from 0V to wave peak and wave trough, and the electronic-type ballast cannot acquire energy from the power grid; when the power grid voltage exceeds the parts close to the wave peak and wave trough, the electronic switch circuit is switched off, and the rectification-type electronic equipment can acquire energy from the power grid. According to the electronic-type ballast, rectification-type equipment only utilizes energy after the power grid voltage exceeds the wave peak and wave trough by controlling the moment in disconnecting and switching off an electronic switch circuit, avoids to utilize the energy of the power grid voltage peak value as well as the energy within the time interval close to the power grid voltage value, can effectively reduce 3rd harmonic component and 5th harmonic component injected into a power grid, reduces the power grid voltage waveform distortion, and improves the power grid electricity energy quality.
Owner:SHANDONG JIANZHU UNIV

Tidal current energy permanent magnet generator with tooth crest temperature measurement structure

The invention discloses a tidal current energy permanent magnet generator with a tooth crest temperature measurement structure, which belongs to the field of generators, and aims to solve the problemthat temperature measurement at a stator tooth pressing plate cannot reflect the real temperature of stator teeth. The generator comprises a stator, a rotor and a rotating shaft, the rotor is fixed onthe rotating shaft, the stator is arranged outside the rotor, and a radial gap exists between the stator and the rotor; the stator is provided with 2N stator teeth, two auxiliary grooves are formed in the tooth top of each stator tooth in the axial direction, a copper bar is embedded into each auxiliary groove, the actual resistance value output by the 4N copper bars in series when the generatoroperates is measured, and the average temperature of the tooth top of the stator is obtained according to the actual resistance value.
Owner:哈动国家水力发电设备工程技术研究中心有限公司 +1

A performance testing method of a voltage transformer

The invention relates to the field of unit testing of high voltage transformer products, in particular to a performance testing method for the voltage transformer. The performance testing method for the voltage transformer is characterized in that a frequency modulation voltage-controlled power source is used as a testing power source and a frequency-modulated and voltage-controlled voltage signal is output, the requirements for the exciting voltage of a secondary winding of a tested voltage transformer are met through voltage rising of an exciting transformer, the induction voltage of the first winding of the tested voltage transformer is collected by a voltage sampler, and monitoring is conducted on the output voltage, the frequency and the output currents of the frequency-modulation voltage-controlled power source and high-voltage feedback of the voltage transformer. Compared with the prior art, the performance testing method for the voltage transformer has the advantages that a third harmonic generation power source large in size is replaced, conveying cost of testing equipment is reduced, testing quality is improved, voltage waveform is improved, and disturbance of higher harmonics is avoided. During the testing process, the no-load voltage ratio and excitation characteristic testing can be achieved under the power frequency conditions, and the voltage transformer is multifunctional. Over-voltage protection can be set, and the safety of the tested voltage transformer can be ensured. Equipment is low in weight and convenient to carry.
Owner:CHINA THIRD METALLURGICAL GRP

Reactive power compensation method and system for micro power grid

The invention relates to a reactive power compensation method and a reactive power compensation system for a micro power grid. The system comprises a distributed measuring unit, a reactive power compensation control unit, a reactive power compensation unit and a communication unit. The micro power grid comprises a distributed power supply with reactive regulation output. For the micro power grid operated in an isolated network mode, the overall reactive power balance condition of the micro power grid is obtained by measuring the active and reactive power distribution conditions of each branchcircuit of the micro power grid, and a reactive power compensation device or the reactive power compensation device and the distributed power supply are subjected to reactive regulation in the micro power grid according to a specific isolated network reactive control strategy to realize the reactive power compensation of the micro power grid. The power factor of the micro power grid can be measured and corresponding reactive power compensation is performed according to the power factor when the micro power grid is operated in a grid-connected mode and in the isolated network mode.
Owner:北京四方华能电气设备有限公司

Low-noise saturable reactor

The invention relates to a low-noise saturable reactor, which can lower the reactance value of the saturable reactor in saturated state. The low-noise saturable reactor comprises a saturable reactor iron core, wherein a reactance coil L1 and a direct-current coil L2 are arranged on one side of the saturable reactor iron core; a reactance coil L3 and a direct-current coil L4 are arranged on the other side of the saturable reactor iron core; the reactance coil L1 and the reactance coil L3 have the same structure and the same number of turns; the direct-current coil L2 and the direct-current coil L4 have the same structure and the same number of turns; the homonymous end of the reactance coil L1 is connected with the synonymous end of the reactance coil L3 and is taken as an alternating-current terminal I of a saturable reactor alternating-current loop; the synonymous end of the reactance coil L1 is connected with the homonymous end of the reactance coil L3 and is taken as another alternating-current terminal II of the saturable reactor alternating-current loop; the homonymous end of the direct-current coil L2 is connected with the synonymous end of the direct-current coil L4 and is taken as a direct-current terminal I of a saturable reactor direct-current loop; and the synonymous end of the direct-current coil L4 is taken as another direct-current terminal II of the saturable reactor direct-current loop.
Owner:SHANDONG UNIV

Mechanical energy storage highway deceleration band power generation device

ActiveCN109098940BSimple structureRealize energy storage and power generationSpring motorMachines/enginesSpeed bumpGear wheel
The invention discloses a mechanical energy storage type highway speed bump power generation device comprising a mechanical transmission part and an energy storage power generation part. The mechanical transmission part mainly comprises a speed bump, a supporting frame, a metal strip, a first crank, a second crank and a driving swing rod, wherein the first crank, the second crank and the driving swing rod are sequentially hinged; one end of the first crank is hinged to the metal strip, the other end of the first crank and the second crank are jointly hinged to a sliding block, the sliding block is mounted in a guiding groove in a supporting plate, and a return spring is mounted on the lower portion of the sliding block in the guiding groove; a driving pawl of a ratchet wheel structure andthe driving swing rod are fixed, a rotating shaft is fixedly connected with a first one-way clutch and a second one-way clutch which are opposite in linkage direction, and the outer circle of the first one-way clutch is fixedly connected with a ratchet wheel; the energy storage power generation part comprises a power generator and a spring-type elastic energy storage device, a mounting gear is arranged on a power generator shaft, and the mounting gear is engaged with an external gear at the outer circle of the second one-way clutch. According to the mechanical energy storage type highway speedbump power generation device, the multistage variable speed is set, the high transmission ratio is achieved as much as possible through the smallest space, mounting is convenient, and the power generation amount is large.
Owner:WUHAN UNIV

Asymmetric connecting wire balancing transformer and implementation method thereof

The invention discloses an asymmetric connecting wire balancing transformer and an implementation method thereof. The transformer comprises an iron core, a primary side winding and a secondary side winding, and is characterized in that: the primary side winding adopts a Y-shaped connecting wire; a neural point N of the Y-shaped connecting wire is grounded; the number of circles of the primary side winding is W1; in the secondary side winding, the A-phase winding consists of two windings, namely ea and ab; the B-phase winding consists of one winding bc; and the C-phase winding consists of two windings, namely dc and ca; the number of circles of the windings ab, bc, ca and dc is W2, and the number of circles of the winding ea is W3; the windings ab, ca and ea are connected with one another at a point a serving as a common point, the windings ca, bc and dc are connected with one another at a point c serving as another common point, and the windings ab and bc are connected with each otherat a point b serving as another common point; two no-load voltages Ueb and Udb are equal to each other; and the phase difference is 90 degrees. The secondary side of the asymmetric connecting wire balancing transformer has an asymmetric winding structure, so the production is convenient to execute, the comprehensive performance is high, the structure is simple, and the material utilization rate is high.
Owner:HUNAN UNIV +2

Commutation Failure Suppression Method for Current Mode HVDC Transmission System Based on Series Voltage Injection

The invention discloses a series voltage injection-based current-type high voltage direct current transmission (LCC-HVDC) system commutation failure suppression method. The core of the method is thatthree-phase voltage series injection is carried out between the inverter of the LCC-HVDC and a receiving-end AC system to compensate dynamic fall of the voltage of the receiving-end AC system, seriesvoltage injection is realized through a unified power flow controller, a parallel transformer of the unified power flow controller is parallelly connected at the AC system side, and a series transformer is serially connected at the inverter side of the LCC-HVDC. A dynamic voltage series injection control algorithm is designed for the series converter of the unified power flow controller, so as toenable the three-phase voltage generated by the series converter of the unified power flow controller to dynamically compensate the dynamic fall of the voltage at the AC system side through the seriestransformer. Voltage distortion and voltage fall at the LCC-HVDC inverter side can be further reduced, and finally, the LCC-HVDC inverter commutation failure possibility is reduced.
Owner:SOUTH CHINA UNIV OF TECH

A Connection Method of Non-60° Phase with Symmetrical Winding

The invention discloses a non-60° phase-band symmetric double-layer stator winding slot number selection, phase-band division and winding connection method, and provides the relationship between the number of poles, the number of branches, the number of slots per pole and each phase, The phase-band division and its specific requirements point out that non-60° phase-band symmetrical double-layer windings can be wave windings or stacked windings, integer slot windings or fractional slot windings, but they must be connected at full pitches. The invention can solve the problems of capacity, rotating speed and voltage mismatch, and achieve the purpose of weakening harmonics and improving voltage waveforms.
Owner:DONGFANG ELECTRIC MACHINERY
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Patsnap Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Patsnap Eureka Blog
Learn More
PatSnap group products