38results about How to "Reduce reactive current" patented technology

The invention relates to a motor, and in particular belongs to an online digital generator system with UPS function. The technical proposal adopted by the invention is as follows: the invention consists of a commercial power controllable rectifier circuit with one end connected with commercial power input and a by-pass control circuit and the other end connected with a back-up battery charging management circuit, a back-up battery pack, a generator controllable rectifier circuit and a common inverter circuit; the back-up battery charging management circuit is connected with the back-up battery pack; the generator controllable rectifier circuit is connected with a generator; the common inverter circuit is connected with the by-pass control circuit; and the by-pass control circuit is connected with a display control circuit and output. The online digital generator system has the advantages of having function of online adjusting the quality of a power supply, and solving the phenomena frequently occurring in electric network, such as electric surge, high-voltage spike pulse, transient overvoltage, voltage sag, electrical wire noise, frequency deviation, sustained low voltage, commercial power interruption and so on.

The invention discloses a control device and method based on a phase angle of a phase current of a direct-current brushless motor. The control device comprises a speed setting module, a central processing unit, a current amplifying circuit, an intelligent power module, Hall sensors and a power source module which provides power for the speed setting module, the central processing unit, the current amplifying circuit, the intelligent power module and the Hall sensors. The control method comprises the steps that the real-time rotation speed of the direct-current brushless motor is collected and counter emf is obtained at the same time; the real-time phase current of the direct-current brushless motor is collected, and speed PI adjustment is conducted on a speed difference between the real-time rotation speed and a set rotation speed, so that a speed adjustment signal is obtained; PWM compensation calculation is conducted on the real-time counter emf and the phase deviation of the phase current of the direct-current brushless motor, so that a PWM compensation amount is obtained; a PWM duty ratio signal is obtained through calculation conducted by the central processing unit according to the speed adjustment signal and the PWM compensation amount; the PWM duty ratio signal is output to the intelligent power module, so that control over the phase of the phase current of the direct-current brushless motor is achieved. By the adoption of the control device and method based on the phase angle of the phase current of the direct-current brushless motor, the motor efficiency is improved, and the amount of emitted-heat is reduced.

The invention discloses a bidirectional hybrid bridge DC-DC converter and a half-cycle volt-second area balance control method, and belongs to a high-frequency switching power supply in the electric power and electronic field. The bidirectional hybrid bridge DC-DC converter disclosed by the invention consists of a main circuit and a control circuit; the main circuit consists of an input side, a high-frequency transformer and an output side; and the control circuit comprises a controller and a driving circuit. Based on the proposed bidirectional hybrid bridge DC-DC converter, half-cycle volt-second area balance control is adopted; the leakage inductance current effective value in a power non-transfer stage can be reduced by adjusting the duty ratio of the input side and by performing the half-cycle volt-second area balance control at the same time, and reactive current can be decreased, thereby lowering circuit on-state loss and ring current loss caused by the current; meanwhile, wide-range soft switching of each switching tube device also can be realized; and in addition, by virtue of the half-cycle volt-second area balance control, real-time control of bidirectional power flow can be realized while the complexity level of the control unit also can be lowered.

The invention discloses a dual-transformer structure-based bidirectional DC-DC converter and a power control method therefor, and belongs to the field of power electronics. The converter consists of a main circuit and a control circuit; the main circuit consists of an input side, an output side and two transformers; and the control circuit comprises a controller and a driving circuit. By adoption of the converter, large-range soft switching of the converter under wide-range voltage input can be realized by means of controlling the input side voltage vAC of the transformer T1, the input side voltage vAB and the output side voltage vFG of the transformer T2, and the phase-shifting angle between vAC and vAB; meanwhile, the loss of the converter can be lowered and the efficiency of the converter can be improved; and at the same time, the proposed power control method is simple in calculation, real-time and reliable, and capable of improving reliability and feasibility of the system.

Cell-to-cell connection plates (1) each integrally having a welding part (2) shaped to fall within a circular end of a battery case (7) and a connecting part (2) extending from this welding part (2) are provided. The cell-to-cell connection plates (1) are attached to one electrode terminal and the other electrode terminal of the battery case (7) by welding the welding parts (2), respectively. The connecting parts (3) of the respective cell-to-cell connection plates (1) attached to each adjoining pair of cylindrical batteries (Ba) are overlapped with each other and coupled into electric connection. Consequently, regardless of whether a plurality of cylindrical batteries (Ba) are axially arranged in series or radially juxtaposed, each adjoining two can be connected to each other by using the identical cell-to-cell connection plates (1) for cost reduction. It is also possible to provide a sufficient heat dissipation effect and achieve sufficient robustness and weight saving even when connecting large-sized cylindrical batteries.

The invention provides a filter for a specific sequence current bypass. The filter comprises a main filter inducer and an auxiliary filter inducer, and is characterized by also comprising a specific frequency series resonance circuit which consists of an inducer and a capacitor, wherein the series resonance frequency of the specific frequency series resonance circuit corresponds to the frequency of ripple current which flows through the main filter inducer. By arranging the series resonance circuit which consists of the inducer and the capacitor on the current bypass and ensuring that the resonance frequency of the series resonance circuit is the same as or similar to the frequency of the ripple current which flows through the main filter inducer, or is the same as or similar to the integral multiple of the frequency of the ripple current which flows through the main filter inducer, a low impedance passage is provided for switching on and off the ripple current, so that the total capacity of the inducer is effectively reduced and additional extra reactive current is greatly reduced. Therefore, equipment cost is greatly reduced and a good technical effect is achieved.

The present invention provides an internal compensation method of AC motor and its winding coupling method. The capacitor internal compensation uses the capacitor to make the interconnected star stator winding respectively produce its current superposition and phase-shifting action to make the resultant currents of two-to-four winding parts divided from every phase approach to that all the phasesare identical and numerical values are uniform so as to raise the induced potential of stator winding and reduce the loss of reactive current. The interconnected star winding has three compensation ends with two or three winding parts led from three-phase stator winding, and can be coupled into several forms of hexagonal-three-star form, hexagonal-six-star form, interconnected star and variable-electrode 3-V type.

A method of executing a bag of tasks application in a cluster over a distributed computing system, the cluster having a cluster resource manager. The method includes requesting that the cluster resource manager authorize access by a remote user of the distributed computing system to any idle nodes of the cluster, submitting a bag of tasks slave process to the cluster resource manager, loading the bag of tasks slave process in one of the idle nodes without an allocation operation, sequentially scheduling tasks from the bag of tasks to the bag of tasks slave process, and executing the bag of tasks slave process either until finished or until the node in which the bag of tasks slave process is loaded is required owing to a local allocation request.

The invention relates to a capacitor optimization configuration method based on an improved particle swarm optimization. The method comprises the following steps of S1, establishing a target functionwith improved voltage quality; S2, establishing a target function with reactive compensation reaching the standard; S3, establishing a target function with the total harmonic distortion rate reachingthe standard; S4, establishing a target function of parallel resonance frequency and series resonance frequency; and S5, establishing a multi-objective optimization model, and carrying out optimizingand configuring on the capacitor by adopting a particle swarm algorithm. Under the condition that resonance and voltage fluctuation are considered, the improved particle swarm algorithm is adopted, the inertia coefficient of the system is controlled by means of the method of presenting the linear descent along with the number of iterations, so that the algorithm can have high global searching performance when starting, the vicinity of the global optimum region can be quickly located, and meanwhile, high local searching performance is achieved; the established optimization model is not only applicable to electric power companies, the capacitor optimization configuration method based on an improved particle swarm optimization and other levels of power transmission and distribution managementdepartments, and is also suitable for a large-scale steel plant, a cement plant and other important harmonic source users.

The invention provides a charging / discharging device and a charging / discharging system for an electric vehicle. The charging and discharging device comprises: a transformer which comprises a primary winding and a plurality of secondary windings, and the plurality of secondary windings at least comprise a first secondary winding and a second secondary winding; the plurality of ports that are respectively and electrically connected with a primary winding and a plurality of secondary windings of the transformer, and the plurality of ports at least comprise: a first port which is electrically connected with the primary winding through a first conversion circuit; a second port which is electrically connected with the first secondary winding through a second conversion circuit; the third port that is electrically connected with the second secondary winding through a third conversion circuit; and the first controllable switch that is connected between the first conversion circuit and the primary winding. The voltage of the first port of the charging and discharging device is a first voltage, the voltage of the second port is a second voltage, and the voltage of the third port is a third voltage.

The invention relates to an underground ultrasonic oil-production transducer with a matching device, in particular to a transducer for solving the problems of extremely low transmission efficiency and serious resource waste of a traditional piezoelectric ceramic transducer transmission system. A fixing frame with a plurality of fixed identical piezoelectric ceramic oscillators is fixedly arranged at the bottom of a cylindrical shell, a fixing frame with two identical fixed inductor matching devices is fixedly arranged at the top of the cylindrical shell, an inductor coil is tightly wound on a hollow cylindrical inductor frame, two incoming terminals of an inductor coil of an inductor matching device hermetically penetrate through the top end surface of the cylindrical shell and are connected with external transmission cables, two outgoing terminals of the inductor coil of the inductor matching device are connected with two incoming terminals of an inductor coil of the other inductor matching device, and two outgoing terminals of the inductor coil of the other inductor matching device are connected in parallel with two terminals of each piezoelectric ceramic oscillator. The invention has the advantages of high transmission efficiency and energy saving.

A power amplifier circuit includes an amplifying transistor and a dc bias circuit for biasing the amplifier transistor to obtain a conduction angle of at least about 180 DEG . The dc bias circuit includes a dynamic bias boosting circuit for increasing the dc bias current provided to the amplifying transistor by the dc bias current in direct proportion to an increase in the input signal provided to the power amplifier. An input to the dc bias circuit is coupled to a stage of the power amplifier circuit by a capacitor. The bias boosting circuit permits the power amplifier circuits to operate in Class B or Class AB with improved linearity, improved efficiency and reduced idle current.

An inter-cell connecting plate (1) having integrally a welding portion (2) to be included in the circular end surface of a cell case (7) and a connection portion (3) extending from the welding portion(2) is provided, welding portions (2) are respectively welded to one electrode terminal of the cell case (7) and the other electrode terminal to fix inter-cell connecting plates (1), and respective connection portions (3) of inter-cell connecting plates (1) respectively fixed to two adjoining cylindrical cells (Ba) are overlapped each other and linked in a electrically connected state, thereby making it possible to connect two adjoining cells together by the same inter-cell connecting plate (1) when a plurality of cylindrical cells (Ba) are disposed either in series axially or in parallel radially, whereby costs can be reduced, sufficient radiation effect is achieved, and sufficient robustness and weight reduction can be ensured even a large cylindrical cells are connected.

An amplifier circuit ( 1 ) includes an amplifying transistor (QØ) and a dc bias circuit ( 2 ) for biasing the amplifier transistor (QØ) to obtain a conduction angle of at least about 180°. The dc bias circuit ( 2 ) includes a self-bias boosting circuit which has a Wilson current-mirror (Q 4 , Q 5 , Q 6 ) integrated with a cascode current-mirror circuit (Q 2 , Q 3 ) to form an extended Wilson current-mirror circuit (Q 2 -Q 6 ) having an output coupled to a control terminal of the amplifying transistor (QØ) by a resistor (R 1 ), and a capacitor (C 2 ) coupled from the extended Wilson current-mirror circuit (Q 2 -Q 6 ) to a common terminal (Gnd).

The invention discloses a control device and method based on a phase angle of a phase current of a direct-current brushless motor. The control device comprises a speed setting module, a central processing unit, a current amplifying circuit, an intelligent power module, Hall sensors and a power source module which provides power for the speed setting module, the central processing unit, the current amplifying circuit, the intelligent power module and the Hall sensors. The control method comprises the steps that the real-time rotation speed of the direct-current brushless motor is collected and counter emf is obtained at the same time; the real-time phase current of the direct-current brushless motor is collected, and speed PI adjustment is conducted on a speed difference between the real-time rotation speed and a set rotation speed, so that a speed adjustment signal is obtained; PWM compensation calculation is conducted on the real-time counter emf and the phase deviation of the phase current of the direct-current brushless motor, so that a PWM compensation amount is obtained; a PWM duty ratio signal is obtained through calculation conducted by the central processing unit according to the speed adjustment signal and the PWM compensation amount; the PWM duty ratio signal is output to the intelligent power module, so that control over the phase of the phase current of the direct-current brushless motor is achieved. By the adoption of the control device and method based on the phase angle of the phase current of the direct-current brushless motor, the motor efficiency is improved, and the amount of emitted-heat is reduced.

A semiconductor device comprises a semiconductor substrate having a main surface; a semiconductor layer of a first conduction type provided on the main surface of said semiconductor substrate; a first buried layer of the first conduction type provided between said semiconductor layer and said semiconductor substrate; a first connection region of the first conduction type provided around said first buried layer, said first connection region extending from the surface of said semiconductor layer to said first buried layer; a switching element provided in the surface region of said semiconductor layer on said first buried layer; and a low breakdown-voltage element provided in a surface region of said semiconductor layer, said low breakdown-voltage element being closer to said first connection region than said switching element and having lower breakdown voltage than that of said switching element.

The invention provides an oil pipeline air compression energy saving device system. Pipe network pressure can serve as a control object; a pressure transmitter converts pressure of an oil pipe to an electric signal to send to a PID intelligent adjuster for comparing with a pressure set value and calculating according to a difference value and a given PID control mode; a generated control signal is sent to an intelligent electricity saving protection system; and the system controls an output power of a motor to enable actual pressure to always approach set pressure. Meanwhile, a commercial power and electricity saving switching function can be added, and a traditional control and protection system is retained; and in addition, after the scheme is adopted, the work of an air compressor motor from standing to rotation can realize soft start by an electricity saving system, so that the start of impact current and the mechanical shock to an air compressor caused by start are prevented.

The invention relates to an intelligent control device of a high power energy saving electromagnetic stove, and the method thereof, The intelligent control device comprises a controllable rectifying and filtering module, a contravariant module and a microcomputer controlling module, which is characterized in that a three-phase alternating current power supply is rectified into an adjustable direct current power supply through the controllable rectifying and filtering module ; the direct current power supply is inverted into a high frequency alternating current power supply through the contravariant module, and then the electric energy is converted into electromagnetic energy to be radiated to the bottom of a cookware, and vortex flow is generated, and the cookware can be heated because ofthe thermal effect of the vortex flow; the microcomputer controlling module is the core of the entire system, which is used for collecting data and transmitting control information to each module; the device adopts a series of advanced control policies, such as the trigger control of the rectifier bridge of an PI regulator, the intelligent self-adaptive constant power control, the intelligent soft-start control, the intelligent cookware detection control, etc., and thereby the working stability and the security of the electromagnetic stove are enhanced. The harmonic pollution of the equipmentto the electric network can be reduced to the utmost extent when the electric energy of the electromagnetic stove is saved, and the electromagnetic stove is suitable for various kitchens and dining rooms.

The invention discloses direct-heating type hot-pressing equipment suitable for producing large-size beryllium materials. The direct-heating type hot-pressing equipment is characterized in that a capacitance on-site compensation device is additionally arranged on a circuit system of an existing 300-ton hot-pressing furnace. The invention provides an equipment capacity expansion method for machining a beryllium material product with the diameter being 300-400 or even larger, and the technical difficulties of the equipment capacity for direct-heating type large-size beryllium material machining are broken through. In addition, the direct-heating type hot-pressing equipment has the advantages that the safe starting and producing capacity of the equipment is achieved, the heating capacity of the equipment is improved, and the rate of finished products is increased.

The invention provides a distribution network loss reduction method based on marketing and distribution big data fusion and a terminal, and the method comprises the steps of: acquiring distribution network operation data, and building a primary key relation between the data; constructing topology logic structure data of the distribution network; fusing the distribution network operation data and the topological logic structure data; respectively calculating user fine-grained loss and distribution network line fine-grained loss; optimizing the reactive power of the power grid; and after the topological logic data of the distribution network structure is established, according to the multi-branch tree topology expression model of the distribution network line, realizing the visualization of the data of the distribution network structure according to the line hierarchy and the topological relationship between branch lines, wires, towers and distribution transformer users. According to the method, on the basis of fusion of distribution network tower topology logic data and distribution transformer operation data, a current and reactive superposition algorithm is innovated, and distribution network line loss fine-grained management and control and distribution network reactive power reduction optimization scheme recommendation are realized; and a dynamic monitoring and early warning function of the operation condition of the distribution network is realized by using a structure visualization technology.

The present invention provides an internal compensation method of AC motor and its winding coupling method. The capacitor internal compensation uses the capacitor to make the interconnected star stator winding respectively produce its current superposition and phase-shifting action to make the resultant currents of two-to-four winding parts divided from every phase approach to that all the phases are identical and numerical values are uniform so as to raise the induced potential of stator winding and reduce the loss of reactive current. The interconnected star winding has three compensation ends with two or three winding parts led from three-phase stator winding, and can be coupled into several forms of hexagonal-three-star form, hexagonal-six-star form, interconnected star and variable-electrode 3-V type.

The patent of the present invention relates to a sine wave high-frequency chain three-level lithium battery inverter device capable of realizing energy feedback, which includes: a lithium battery; Device electrical connection; secondary side active rectifier device; active clamping circuit, control circuit. The voltage output by the lithium battery is inverted and converted into a square-wave alternating current carrying sine wave information through the front-end inverter, and the high-frequency transformer is used to boost the voltage, and the alternating current carrying sine wave information is converted through the secondary-side active rectifier device Select different winding voltages (three levels) for demodulation and extraction according to the phase, and then filter through inductance and capacitance to convert it into alternating current in the form of a sine wave. The focus of this patent is to adopt a high-frequency chain and multi-level solution. The important intermediate energy conversion link uses a high-frequency transformer and a multi-level circuit, which reduces harmonics and reactive current; this patented control scheme not only reduces The weight of the whole machine is reduced, and the system efficiency is also improved.

The invention provides a distribution network loss reduction method and a terminal based on the integration of big data of operation and distribution, which can obtain distribution network operation data, establish a primary key relationship between the data, construct distribution network topology logical structure data, and compare distribution network operation data with topology Integrate the logical structure data; calculate the fine-grained loss of users and the fine-grained loss of the distribution network separately; optimize the reactive power of the power grid; after the topology logic data of the distribution network structure is established, the model is expressed according to the multi-branch tree topology of the distribution network. , and realize the visualization of distribution network structure data according to the line hierarchy and branch lines, wires, towers, and distribution transformer users. The method is based on the integration of distribution network tower topology logic data and distribution transformer operation data, and innovative current and reactive power superposition algorithm to realize fine-grained control of distribution network line loss and recommendation of distribution network reactive power reduction optimization scheme. Dynamic monitoring and early warning function of distribution network operation status.

The invention relates to a low-voltage reactive power compensation connection technology of a submerged-arc furnace, in particular to a reactive power compensation connection method of the low-voltage side of a high-capacity submerged-arc furnace. According to the reactive power compensation connection method of the low-voltage side of the high-capacity submerged-arc furnace, a capacitor device is arranged on an electrode system, and a short net copper pipe is arranged between an electrode water-cooling cable and a copper tile. A copper bar is welded on the short net copper pipe, and the electrode water-cooling cable is connected to the copper bar. The water-cooling cable is connected with a reactive power compensation device through the short net copper pipe, and the length of the water-cooling cable is equal to that of the water-cooling cable connected with a short net of the submerged-arc furnace. The sectional area of the water-cooling cable is 2000mm<2>, the outer diameter of the copper pipe is 60mm, the inner diameter of the copper pipe is 40mm, and the wall thickness of the copper pipe is 10mm. According to the reactive power compensation connection method of the low-voltage side of the high-capacity submerged-arc furnace, a connection joint of the compensation device is moved forwards to the joint of the water-cooling cable and the copper tile and directly compensated to an electrode end, therefore, on-site compensation is truly achieved, and the aim of reactive power on-site balance is achieved. The smelting characteristic of the submerged-arc furnace is thoroughly improved, the aims of increasing yield and reducing consumption are achieved, and the best compensation effect is achieved.

The invention discloses a bidirectional DC-DC converter based on a double transformer structure and a power control method thereof, belonging to the field of power electronics. The converter of the invention is composed of a main circuit and a control circuit; the main circuit is composed of an input side, an output side and two transformers; the control circuit includes a controller and a driving circuit. The present invention controls the transformer T 1 The input side voltage v AC , Transformer T 2 The input side voltage v AB and the output side voltage v FG and v AC , v AB The phase shift angle between them can realize a wide range of soft switching of the converter under a wide range of voltage input, and at the same time can reduce the loss of the converter and improve the efficiency of the converter. At the same time, the proposed power control method is simple in calculation, reliable in real time, and improves the reliability and implementability of the system.

The invention relates to a voltage fault ride-through test method for a static var generator. The method specifically includes at least one static var generator for accompanying testing, the static var generators for accompanying testing and a to-be-tested static var generator are connected with the output end of a grid fault simulation test device in parallel, the reactive supporting current characteristics of the static var generators for accompanying testing under voltage fault ride-through are reversed, the reactive current output by the to-be-tested static var generators is offset partially or completely, so that the total current output by the grid fault simulation test device does not exceed the rated current of the grid fault simulation test device, and thus the purpose of reducingthe capacity requirement of the grid fault simulation test device and reducing the cost of a voltage fault ride-through test is achieved.

A power amplifier circuit includes an amplifying transistor and a dc bias circuit for biasing the amplifier transistor to obtain a conduction angle of at least about 180 DEG . The dc bias circuit includes a dynamic bias boosting circuit for increasing the dc bias current provided to the amplifying transistor by the dc bias current in direct proportion to an increase in the input signal provided to the power amplifier. An input to the dc bias circuit is coupled to a stage of the power amplifier circuit by a capacitor. The bias boosting circuit permits the power amplifier circuits to operate in Class B or Class AB with improved linearity, improved efficiency and reduced idle current.