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564 results about "Single-phase electric power" patented technology

In electrical engineering, single-phase electric power is the distribution of alternating current electric power using a system in which all the voltages of the supply vary in unison. Single-phase distribution is used when loads are mostly lighting and heating, with few large electric motors. A single-phase supply connected to an alternating current electric motor does not produce a rotating magnetic field; single-phase motors need additional circuits for starting (capacitor start motor), and such motors are uncommon above 10 kW in rating.

Field data verification device based on money-free clamp buckle type single-phase electric energy meter

The invention provides a field data verification device based on a money-free clamp buckle type single-phase electric energy meter, and the device comprises a host which is used for starting a measurement process through the contact of a probe with a signal contact of the electric energy meter, receiving current data transmitted by a wireless clamp-shaped current transformer, and carrying out the filtering, calibration and error analysis of the measurement data; and the wireless split core type current transformer is used for being clamped on a current loop of the measured electric energy meter, starting to measure current data and sending the current data to the host in a wireless mode. According to the invention, a wireless communication technology, a field data processing algorithm and a verification function are integrated, and field real-time data acquisition, processing, analysis and verification can be realized, so that the efficiency and accuracy of verification work are improved.
Owner:ZHUHAI KEHUI ELECTRICAL APPLIANCE CO LTD

Single-phase electric energy meter with magnetic ring compensation structure

The invention belongs to the technical field of electric energy meters, and particularly relates to a single-phase electric energy meter with a magnetic ring compensation structure. The device comprises a gap magnetic ring modeling unit, a compensation coil current setting unit, a driving voltage real-time generation unit and a pulse output unit, the notched magnetic ring modeling unit is used for calculating corresponding uncompensated magnetic flux based on the magnetic conductivity after temperature correction; the compensation coil current setting unit is used for forming a compensation coil current setting value; the driving voltage real-time generation unit is used for injecting bidirectional current matched with a compensation coil current set value into the compensation coil; the pulse output unit is used for triggering metering pulse output; the method has the beneficial effects of high precision, high stability, low power consumption and high robustness.
Owner:SHENZHEN FRIENDCOM TECH DEV +1

Low-voltage line single-phase distributed energy storage system and control method thereof

The invention relates to the technical field of low-voltage single-phase energy storage, and discloses a low-voltage line single-phase distributed energy storage system and a control method thereof.The energy storage system comprises a control system and a plurality of distributed independent energy storage systems, and each independent energy storage system comprises a controller, a converter and an energy storage unit; the controllers are respectively connected with the converters and the energy storage units, the energy storage units are connected with the single-phase low-voltage lines through the converters, the controllers are in communication connection with the control system, and the control system controls the converters to charge and discharge electric energy according to the power grid environment where the energy storage units are located. The safety detection of each independent energy storage system is realized through a single battery self-checking device and a system self-checking component of each independent energy storage system, the charging and discharging states of each battery are safely controlled, and each independent energy storage system realizes precise voltage support and flexible energy buffering through single-phase independent regulation and control; dynamic optimization of single-phase electric energy quality is realized by adopting a power control strategy, and the technical blank of traditional centralized energy storage in the field of single-phase electric energy regulation and control is filled.
Owner:HENAN RUITONG ELECTRIC TECH CO LTD

Air door motor control method and system based on current detection

The invention relates to the technical field of air door motor control, and discloses an air door motor control method and system based on current detection, and the method comprises the steps: carrying out the single-phase current signal collection of an air door motor system, and obtaining a current change signal in the opening and closing process of an air door; carrying out FFT (Fast Fourier Transform) and wavelet decomposition processing on the current change signal to obtain a current characteristic spectrum component and a time domain characteristic; processing the current characteristic frequency spectrum component and the time domain characteristic to obtain an air door load current characteristic; iterative learning control is executed, and air door rotating speed control parameters are generated; the PWM duty ratio is calculated, and air door motor driving pulses are generated; according to the air door motor control method, a complete air door motor control protection mechanism is established, abnormal conditions such as stalling can be detected and coped with in time, the safety of an air door motor system is improved, and the service life of the air door motor system is prolonged.
Owner:深圳市远望工业自动化设备有限公司

Non-contact power transmission line fault monitoring method and device

The invention relates to the technical field of electrical variable measurement, in particular to a non-contact power transmission line fault monitoring method and device, and the method comprises the steps: collecting all kinds of three-phase electrical parameters of a power transmission line at all moments; dividing any type of single-phase electrical parameters at all moments into periods, forming a single-phase electrical parameter sequence by using any type of single-phase electrical parameters of each period, and determining a jitter coefficient and a fundamental frequency deviation coefficient of the single-phase electrical parameter sequence of each period; obtaining a distortion coefficient of the single-phase electrical parameter sequence of each period; determining the adjacent distinction degree and the peak distinction degree of the single-phase electrical parameter sequence of each period; obtaining a difference coefficient of the single-phase electrical parameter sequence of each period; taking a fusion result of the difference coefficients of any type of three-phase electrical parameters of each period as local difference of any type of three-phase electrical parameters of each period; and obtaining a fault monitoring result of the power transmission line. Therefore, the accuracy of power transmission line fault monitoring is improved.
Owner:LUOYANG LONGYU ELECTRICAL EQUIP +4

Single-phase voltage stabilizer and control method and system thereof

The invention discloses a single-phase voltage stabilizing device and a control method and system thereof. Compared with a traditional single-phase full-bridge PWM rectifier and a single-phase full-bridge inverter, the single-phase voltage stabilizing device has the advantages that one bridge arm is reduced, the device cost is lower, fewer devices are needed, fault nodes are correspondingly reduced, and the reliability is higher. The problem of control coupling of a grid-connected input side and an inverter output side is caused due to the fact that one bridge arm is shared, the inverter output side voltage is given to be associated with a grid side, the phases of the inverter output side voltage and the grid side are synchronized, then pulses of the shared bridge arm are naturally decoupled, and the output sinusoidal voltage is obtained. Meanwhile, due to the full-bridge PWM rectification control mode adopted by the grid-connected input side, the grid-side power factor can be 1, and the grid-side current is sinusoidal, so that green grid connection of the device is realized; the inverter output side tracks the network side voltage and introduces the direct current bus voltage as negative feedback, so that the stability of the output voltage is ensured, the stable single-phase voltage output is finally obtained, and the quality of the power supply electric energy in the substation is improved.
Owner:NANJING INST OF RAILWAY TECH

Power output switching device and system

The embodiment of the utility model relates to the electrical field, and discloses a power output switching device and system. The power supply output switching device comprises two three-phase input ends, two three-phase output ends, two single-phase output ends and a switching matrix, the two three-phase input ends are respectively connected with a three-phase power supply; the switching matrix is used for controlling the conduction state of each phase line level circuit between each three-phase input end and the two three-phase output ends and between each three-phase input end and the two single-phase output ends. Therefore, the three-phase power supply directly outputs three-phase power through the three-phase output end, or the three-phase power supply is adjusted to be a single-phase power supply and then single-phase power is output through the single-phase output end. According to the scheme, different line topologies are formed by controlling the conduction of each phase line level line in the switching matrix, different output modes can be realized, the workload of manual wiring is greatly reduced, the test efficiency is improved, the structure is simple, the implementation is easy, and the cost is saved.
Owner:SHANGHAI KELIANG INFORMATION ENG

Open-circuit fault detection method, device, domain controller, system and vehicle

The invention relates to an open-circuit fault detection method and device, a domain controller, a system and a vehicle, and relates to the technical field of open-circuit fault detection. According to the method, the three-phase current data of the cooling water pump can be firstly obtained, and under the condition that at least one phase of current data in the three-phase current data meets the pre-judged open circuit condition, at least one of the following motor parameters including the three-phase current unbalance degree, rotor data and water pump vibration data is monitored. If it is monitored that any motor parameter in the three-phase current unbalance degree, the rotor data and the water pump vibration data is abnormal, it is determined that the current data meeting the pre-judgment open-circuit condition occurs, and an open-circuit fault occurs to the target phase corresponding to the current data meeting the pre-judgment open-circuit condition. Therefore, under the condition that the suspected open circuit of the corresponding phase is predicted according to the single-phase current, prediction can be performed by fusing at least one motor parameter of the cooling water pump, so that the misjudgment rate of the open-circuit fault of the cooling water pump can be reduced and the open-circuit phase positioning precision can be improved through multi-data cooperative detection.
Owner:CHONGQING CHANGAN AUTOMOBILE CO LTD

Inductor and single-phase power converter

A first winding is wound around a first middle column of a first magnetic core, and a second winding is wound around a second middle column of a second magnetic core. The third magnetic core is located between the first winding and the second winding, the third magnetic core has a through hole, and both the first middle column and the second middle column extend into the through hole. When a direction of a magnetic field generated by the first winding is the same as a direction of a magnetic field generated the second winding, the first magnetic core and the second magnetic core generate common-mode inductance. When a direction of a magnetic field generated by a third winding is opposite to a direction of a magnetic field generated a fourth winding, the third magnetic core generates differential-mode inductance.
Owner:HUAWEI DIGITAL POWER TECH CO LTD

Load-limiting open circuit control method and system for low-voltage power line, and storage medium

The invention relates to the technical field of low-voltage power line control, and discloses a low-voltage power line load-limiting open circuit control method and system and a storage medium, and the method comprises the steps: obtaining A, B, C and N phase currents; if at least one of the four phases of current exceeds the reference value and lasts for a first time value, the N phases are disconnected; or, if the current sum value of the four-phase current is within the reference range and lasts for a second time value, the N phase is disconnected; the power factor compensation circuit is cut out and connected into the resonance circuit; after the first delay time is continued, the N phase is connected, the resonance circuit is switched out, and the power factor compensation circuit is connected; calculating the time interval value of the latest x N-phase cut-off, and adjusting the single-phase current reference value according to the positive correlation of the average value of the time interval value; and calculating the distribution uniformity of the time point of the latest N-phase cut-off for y times on the time axis, and adjusting the total current reference range according to the positive correlation of the uniformity. The device has the advantages that the load can be limited without power failure, and mis-tripping is not easy to occur.
Owner:STATE GRID SHANGHAI MUNICIPAL ELECTRIC POWER CO

Bidirectional vehicle-mounted charging circuit and circuit control method

The invention discloses a bidirectional vehicle-mounted charging circuit and a circuit control method. The topology comprises a front-stage totem-pole bridgeless PFC and a rear-stage bidirectional CLLC converter; the bidirectional totem-pole bridgeless PFC converter is connected with a 220V single-phase power grid; the rear-stage bidirectional CLLC converter is connected with the bidirectional totem-pole bridgeless PFC converter; the forward resonance link and the reverse resonance link of the rear-stage bidirectional CLLC converter are the same so that soft switching can be achieved conveniently, and the rear-stage bidirectional CLLC converter is finally connected with the power battery of the electric vehicle and is combined with the front-stage totem-pole bridgeless PFC to charge the power battery. According to the invention, the vehicle-mounted charging circuit has G2V and V2G functions, the output voltage range is adjustable in a range of 300V-500V, and the applicability and the safety are improved.
Owner:XIAN UNIV OF TECH

Starter / generator arrangements for gas turbine engines

A variable frequency starter generator (VFSG) system includes a VFSG having a start mode and a generate mode, a permanent magnet generator (PMG) and a main generator section and an exciter section. The system also includes a controller electrically connected to the VFSG. The controller flow start mode three phase electrical power from aircraft power to the exciter of the VFSG in the start mode and flows single phase electrical power to the exciter of the VFSG in the generate mode. The controller includes: an input active rectifier that receives input AC power and converts it to DC power and provides it to across a positive rail and negative rail; an output inverter coupled to an output of the input active rectifier; and one or more line inductors connected along one or both of the positive rail and negative rail between the input active rectifier and the output inverter.
Owner:HAMILTON SUNDSTRAND CORP

Field calibration device, method and system applied to single-phase electric energy metering device

The invention provides an on-site calibration device, method and system applied to a single-phase electric energy metering device, and relates to the technical field of metering device calibration, and the device comprises a main body, a display screen and a clamp meter. A crimping panel is arranged on the lower end surface of the main body; a plurality of crimping needles are arranged on the crimping panel, and the crimping needles are matched with crimping holes formed in the single-phase electric energy metering device to realize crimping; a locking nut is arranged on the main body, the locking nut penetrates through the main body from top to bottom, and the main body is fixed on the single-phase electric energy metering device through the configuration of the locking nut and a threaded hole formed in the single-phase electric energy metering device. According to the invention, the device main body and the single-phase electric energy metering device are buckled together, a worker can leave the field only by completing buckling, and returns to the field to be taken back after the device completes automatic inspection, so that the worker efficiency and multi-point inspection are both considered, and the overall performance of the single-phase electric energy meter within the working range of the single-phase electric energy meter is inspected.
Owner:SHENZHEN SINGHANG ELEC-TECH CO LTD

Overvoltage risk assessment method, device and equipment for non-full-phase operation of new energy access weak grid system

The invention relates to an overvoltage risk assessment method, device and equipment for non-full-phase operation of a new energy access weak power grid system. The method comprises the following steps: acquiring electrical quantity data of the new energy access weak power grid system, and a voltage source, grid-connected equivalent impedance, series equivalent impedance and non-full-phase operation line impedance of a power transmission line of the new energy access weak power grid system with a single-phase fault; calculating n positive sequence current vectors and negative sequence current vectors according to each piece of electrical quantity data; calculating n positive sequence port voltage vectors and negative sequence port voltage vectors according to the fault data, each positive sequence current vector and each negative sequence current vector; according to the positive sequence voltage component rated value, each positive sequence port voltage vector and each negative sequence port voltage vector, actual positive sequence voltage and actual negative sequence voltage are obtained through calculation; and according to the actual positive sequence voltage, the actual negative sequence voltage and the positive sequence voltage component rated value, calculating to obtain a single-phase voltage maximum value, and according to the single-phase voltage maximum value, judging whether the system has an overvoltage risk in a non-full-phase operation state.
Owner:ELECTRIC POWER RES INST CHINA SOUTHERN POWER GRID CO LTD +1

Novel low-voltage multi-port single-phase power supply equipment control method

The invention relates to the technical field of power distribution network management, in particular to a novel low-voltage multi-port single-phase power supply equipment control method. Comprising the steps that novel low-voltage single-phase multi-port power supply equipment composed of an AC / DC converter, three DC / AC converters and a middle direct-current bus is constructed; firstly, a Vdc-Q control mode is adopted to carry out DC bus voltage control, secondly, a Vf virtual synchronous machine control mode is adopted to carry out single-phase voltage frequency control, and finally, single-phase source network load storage coordinated optimization control is carried out. According to the design, independent control over power supply of the phases A, B and C in the three phases is achieved through the electric power technology and equipment, safe and reliable power supply of the phases is guaranteed, and meanwhile multi-main-body optimization among distributed photovoltaic, energy storage and loads can be achieved; the electric energy quality problems of three-phase imbalance, harmonic waves, voltage fluctuation and flicker and the like of a low-voltage three-phase line can be fundamentally solved through direct-current bus isolation, and the electric energy quality management system has outstanding advantages in the aspects of electric energy quality management effect and management cost.
Owner:XUCHANG POWER SUPPLY COMPANY OF STATE GRID HENAN ELECTRIC POWER

Fault test and ride-through method for grid-connected inverter of hydrogen fuel cell

The invention belongs to the technical field of power grids, and particularly relates to a hydrogen fuel cell grid-connected inverter fault test and ride-through method. Comprising the following steps: S1, simulating three-phase symmetrical voltage drop, inter-phase voltage drop and single-phase voltage drop of a power grid through a low-voltage fault generation device; s2, collecting the voltage of a power grid through a high-precision voltage sensor, and when the voltage of the power grid drops, judging whether the system needs to carry out low-voltage ride through at the moment according to a distributed energy low-voltage ride through curve; and S3, when the system needs to carry out low-voltage ride-through, a dual-second-order generalized integrator pre-filtering phase-locked loop (DSOGI-PLL) is combined with grid-connected point voltage full-feedback compensation, negative-sequence components generated by symmetric and asymmetric drop of the power grid voltage are eliminated, and current impact suppression and negative-sequence current elimination are realized. The problem of power grid synchronization under the condition of power grid voltage drop is finally solved.
Owner:ELECTRIC POWER SCI RES INST OF STATE GRID XINJIANG ELECTRIC POWER CO LTD

Method and system for predicting single-phase electric energy meter burning based on electric energy meter data

The invention discloses a single-phase electric energy meter burning prediction method and system based on electric energy meter data, and relates to the technical field of intelligent early warning of single-phase electric energy meters. According to the method, the historical time sequence data of the single-phase electric energy meter is analyzed to obtain a three-dimensional array Xrested, multiple engineering features are further extracted from a multi-dimensional angle to obtain a multi-dimensional array X'eng, a more comprehensive and more robust risk assessment basis is provided for the model, and the generalization ability of the model is improved; moreover, the invention provides a meter burning prediction model combining the advantages of deep learning and machine learning, the internal law of the data of the electric energy meter can be fully mined, and the high-precision prediction of the risk of meter burning is realized. According to the invention, the problems of limitation and poor effect of the existing single-phase electric energy meter prediction technology are solved.
Owner:ANHUI ZENITH ELECTRICITY & ELECTRONICS

Electric energy metering error compensation method, device and system

The invention relates to the technical field of electric energy metering error compensation, in particular to an electric energy metering error compensation method, device and system, and the method comprises the steps: collecting a single-phase electric energy signal of a secondary side of a power grid transformer, and uniformly dividing the single-phase electric energy signal into each section of metering signal sequence; calculating high-frequency unsteady-state energy to quantify distortion by extracting first-order and second-order quasi-steady-state components of a metering signal sequence; meanwhile, impact pulses in the dynamic components are recognized, impact characteristics are analyzed through clustering, and the nonlinear impact disturbance degree is comprehensively calculated; the fundamental wave separation strength of each section of metering signal sequence is calculated, the initial step length factor of the LMS filtering algorithm is dynamically adjusted, effective separation of fundamental waves and distortion signals is achieved, and therefore electric energy metering error compensation is completed. The method aims at solving the problem that the metering precision of a traditional fixed step length factor is reduced under the power grid nonlinear load high permeability working condition, and the accuracy and reliability of electric energy metering are ensured.
Owner:STATE GRID HEILONGJIANG ELECTRIC POWER CO LTD SHUANGYASHAN POWER SUPPLY CO

A method, device, electronic device and storage medium for detecting abnormal current

The present invention discloses a current anomaly detection method, device, electronic device and storage medium, which relate to the field of motor control. The method obtains the real-time N-phase current of the N-phase motor in the current cycle, determines the reference current value corresponding to each phase of the N-phase motor in a preset coordinate system, and / or transforms the real-time N-phase current to the preset coordinate system to obtain each corresponding real-time current value; determines whether there is a current abnormal phase according to the sum of all real-time current values; if there is a current abnormal phase, locates the current abnormal phase and the current normal phase according to the difference between each corresponding reference current value and the real-time current value. It can be seen that the scheme can quickly and efficiently locate the specific phase of the current sampling abnormality, rather than just identifying the existence of the current abnormality, and solves the stability and reliability problems caused by single-phase current sampling abnormality in PMSM control.
Owner:INVT ELECTRIC VEHICLE DRIVE TECH SHENZHEN CO LTD

Grounding loop test method and system in operation state of high-voltage cable

According to the grounding loop test method and system in the high-voltage cable operation state, the current response signal and the voltage response signal generated by responding to the excitation signal are analyzed through vector spectrum, and tiny but key changes along with signal instability in an electric power system can be detected more sensitively; a basis is provided for a waveform anomaly detection task; the voltage response three-dimensional spectrogram semantic feature vector and the current response three-dimensional spectrogram semantic feature vector are subjected to optimization analysis through external knowledge in combination with a self-attention mechanism, and while the semantic expression of the self-response three-dimensional spectrogram semantic feature vector is improved, the self-attention mechanism of the three-dimensional spectrogram semantic feature vector is improved. The method is beneficial for capturing interaction between spectrogram semantics in the current and voltage response signals, can perform subsequent single-phase resistance test under the condition of ensuring waveform stability, and is beneficial for improving accuracy and reliability of a grounding loop resistance test result.
Owner:STATE GRID SHANDONG ELECTRIC POWER CO

Multi-structure self-adaptive electric energy meter non-power-cut replacement device and use method

The invention relates to a multi-structure self-adaptive electric energy meter non-power-cut replacement device and a use method. The multi-structure self-adaptive electric energy meter non-power-cut replacement device comprises a control host connected with a single-phase electric meter; the wire inlet side and the wire outlet side of the single-phase electric meter are respectively connected with switches of the same type or different types, the switch of the wire inlet side is connected with a power supply side socket of the control host through a wire inlet electricity taking module, the switch of the wire outlet side is connected with a user side socket of the control host through a wire outlet electricity taking module, and the control host and the single-phase electric meter form a parallel bypass; the lower part of the single-phase ammeter is provided with a connection terminal area, the connection terminal area is provided with four ammeter buses which are arranged at intervals, and each ammeter bus is locked with the single-phase ammeter through a wire locking screw. The connection terminal area is detachably connected with a short circuit module, the short circuit module is connected with the control host and the locking wire screw, the adjacent ammeter buses are locked or loosened by adjusting the locking wire screw, the single-phase ammeter is seamlessly switched from an original circuit to a parallel bypass, and meanwhile the passing electric quantity is continuously metered.
Owner:STATE GRID FUJIAN ELECTRIC POWER CO LTD +4

Systems and methods for monitoring an electrical distribution system

An electrical conductor monitoring system for single or multi-phase conductors is described. The monitoring system may be configured to monitor the health of a conduction system based on multi-phase sequences and / or current magnitude and angle vectors of multi-phase or single-phase current. In one example, the monitoring system includes an insulation health monitoring system having an input and output measurement devices, the input measurement device disposed at an input end of the electrical distribution system and structured to measure three-phase input currents, the output measurement device disposed at an output end of the electrical distribution system and structured to measure three-phase output currents; and a monitoring device communicatively coupled to the measurement devices and structured to receive the three-phase input and output currents from the measurement devices and determine a state of the insulation system based on the three-phase input and output currents. Other embodiments are described.
Owner:EATON INTELLIGENT POWER LTD

Voltage and current phase sequence identification device based on single-phase voltage sampling and others

The invention belongs to the technical field of power grids, and relates to a voltage and current phase sequence recognition device based on single-phase voltage sampling and others, the phase sequence recognition device comprises a device power supply unit, a voltage sampling unit, three current detection units and a data processing unit, the device power supply unit is connected in parallel with the voltage sampling unit, and the three current detection units are connected in parallel with the data processing unit. The voltage sampling unit carries out voltage sampling on any phase line in the three-phase four-wire system power grid, the three current detection units carry out current sampling on each phase line of the three-phase four-wire system power grid, and the data processing unit reconstructs voltage signals of the other two phases according to voltage sampling models and current sampling signals. And identifying the phase sequence of the voltage and the current of the three-phase four-wire system power grid. According to the invention, the phase sequence identification of the three-phase line voltage and the three-phase current can be carried out only by sampling the single-phase voltage signal and the three-phase current signal, and the method has the characteristics of fast phase sequence identification speed and high efficiency, and also has the characteristics of simple installation, convenient use and plug-and-play.
Owner:HANGZHOU QINGKE DIGITAL TECHNOLOGY CO LTD

Electric energy metering method and system, storage medium and product

The invention provides an electric energy metering method and system, a storage medium and a product, and belongs to the technical field of electric energy metering. The method comprises the following steps: acquiring a single-phase instantaneous voltage signal and a single-phase instantaneous current signal corresponding to each sampling point of a single-phase power grid; determining single-phase instantaneous power according to the single-phase instantaneous voltage signal and the single-phase instantaneous current signal; determining a zero crossing point of a voltage fundamental wave signal in the single-phase instantaneous voltage signal; calculating the number of instantaneous sampling points in the time period of two adjacent zero crossing points; determining a single-phase power average value according to the instantaneous sampling point number and the single-phase instantaneous power in the time period of two adjacent zero crossing points; and performing electric energy integration on the single-phase power average value to obtain single-phase electric energy and a single-phase electric energy pulse. By means of the method, it can be avoided that a low-pass filter in the prior art is used for filtering alternating components in the power signals, electric energy loss is reduced, and the problem that in the prior art, electric energy loss is too much is solved.
Owner:SHENZHEN RENERGY TECH

Calibration device and calibration method

The invention discloses a calibrating device and a calibrating method. The calibrating device comprises a base and a plurality of current columns. The plurality of current columns are respectively connected to the base, each current column extends along a first direction, and each current column is arranged along a second direction crossed with the first direction; in the first verification state, a first verification group and a second verification group formed by the current column modules are used for correspondingly verifying two three-phase mutual inductor access type electric energy meters; in the second verification state, a third verification group and a fourth verification group formed by the current column modules are used for correspondingly verifying two three-phase direct access type electric energy meters; and in the third verification state, a fifth verification group, a sixth verification group and a seventh verification group formed by the current column modules are used for correspondingly verifying three single-phase electric energy meters. According to the invention, the compatibility of the single-phase electric energy meter and the three-phase electric energy meter can be improved, so that the current column of the calibrating device is more accurately butted with the single-phase electric energy meter and the three-phase electric energy meter.
Owner:SHENZHEN CLOU POWER TECH CO LTD

Circuit structure for controlling operation of single-phase motor

The utility model provides a circuit structure for controlling operation of a single-phase motor, which comprises an operation winding and a starting winding which form a stator coil in the single-phase motor, and further comprises a timer and a timing switch. The starting winding and the timing switch are connected in series and then connected in parallel with the timer and the operation winding between two ends of the AC power supply. Wherein the timer is in signal connection with the timing switch, and the timing switch is in a normally closed state; and after the preset time countdown of the timer is finished, the timer sends a turn-off signal to the timing switch, so that the timing switch is converted from a normally-closed state to an off state. According to the circuit structure for technically controlling the operation of the single-phase motor, the timer and the timing switch ensure that the starting winding is accurately disconnected within the preset time, the motor is prevented from being overheated, and the starting efficiency and durability are improved.
Owner:GTA SEMICON CO LTD

A new type of lobular magnetic shielding partial discharge detection device and detection method

The application discloses a novel lung lobe-shaped magnetic shielding partial discharge detection device and a detection method. The device comprises an isolation transformer, a bushing, a detection electrode and a partial discharge instrument. A single-phase power supply is connected with a reactor in parallel, and then connected with an input end of the isolation transformer. One end of an output end of the isolation transformer is connected with the bushing, and then connected with the detection electrode. The other end of the output end of the isolation transformer is grounded. A grounding end of a to-be-detected lung lobe-shaped magnetic shielding is grounded, and the grounding end of the to-be-detected lung lobe-shaped magnetic shielding is connected with the partial discharge instrument. The to-be-detected lung lobe-shaped magnetic shielding and the detection electrode are correspondingly arranged to form an equivalent capacitor and are coupled and connected. The application can be used to determine whether there is a defect in the lung lobe-shaped magnetic shielding by performing a partial discharge test on the lung lobe-shaped magnetic shielding before the lung lobe-shaped magnetic shielding is assembled into a transformer. The application has the characteristics of high test efficiency and low applied voltage, and greatly improves the first-time pass rate of the transformer product provided with the lung lobe-shaped magnetic shielding.
Owner:CHANGZHOU TOSHIBA TRANSFORMER

A method for establishing optimal power flow model for three-phase unbalanced distribution network

The present invention relates to a method for establishing an optimal power flow model of a three-phase unbalanced distribution network, and belongs to the technical field of power flow optimization of a three-phase unbalanced distribution network. With the large-scale access of electric vehicles and photovoltaic power generation systems to the power grid, the single-phase power supply within the distribution network has increased, the load has increased, and the severity of its single-phase operation problem has been aggravated. In order to ensure the power supply quality of the power grid, a large number of adjustable single- and three-phase compensation and regulation equipment have been used in the power grid. Taking into account the above power grid operation conditions, the present invention first establishes a multi-period distribution network optimal power flow model containing reactive compensation devices and energy storage; through second-order cone programming, the original non-convex nonlinear optimal power flow model is transformed into a linear model, which reduces the difficulty of solving without losing accuracy and improves the solution efficiency. It provides a good reference for subsequent research on the three-phase imbalance problem in the optimal power flow process of the distribution network.
Owner:KUNMING UNIV OF SCI & TECH

A method and system for metering power loss during replacement of an electricity meter

The application discloses a kind of electric energy meter replacement period electric quantity loss metering method and system, first determine the electric voltage test loop quantity involved in electric quantity metering of the electric energy meter to be replaced, and configure the pair of current transformer clamp and single-phase electric energy meter for each electric voltage test loop;The pair of current transformer clamp is respectively clamped to the current input line, output line of each electric voltage test loop high voltage phase, and the single-phase electric energy meter is connected to the secondary winding of corresponding current transformer clamp;Then, the secondary winding of high-voltage current transformer connected to the electric energy meter to be replaced is short-circuited, and the power consumption wh1 on the single-phase electric energy meter at this stage is recorded;The electric energy meter to be replaced is removed, and the power consumption wh2 on the single-phase electric energy meter at this stage is recorded;New electric energy meter is connected to joint terminal box, and the power consumption wh3 on the single-phase electric energy meter at this stage is recorded;Finally, the power consumption loss during electric energy meter replacement is calculated according to wh1, wh2 and wh3.The application is more efficient and safer.
Owner:STATE GRID JIANGSU ELECTRIC POWER CO LTD NANJING POWER SUPPLY COMPANY