8333 results about "Current transformer" patented technology

There is provided an inductive power line data coupler. The coupler includes (a) a magnetic core having a high magnetic permeability at a data communication frequency and being configured to allow a power line of a power distribution system to be routed through the magnetic core to serve as a primary winding, (b) a data signaling circuit that provides a secondary winding through the magnetic core for coupling a data signal between the power line and a communication device, and (c) a choke coil coupled to the data signaling circuit for creating a flux-canceling power frequency current opposite in direction and comparable in magnitude to a power frequency current. The coupler may also include a circuit for sensing a level of current in the power line.

A system and method of monitoring a plurality of electrical assets comprise an electricity distribution infrastructure, including a plurality of electrical asset sensors coupled to the electrical assets for monitoring an operating condition of the electrical assets as well as any fault conditions. The sensors may include a current transformer for obtaining a current waveform, a GPS receiver for applying a synchronized time-stamp to the waveform data, and a mesh network radio for transmitting the time-stamped waveform data. Data from the plurality of sensors may be encrypted and transmitted over a mesh network to one or more gateways that are in communication with a central command processor. In response to an abnormal operating condition of any electrical asset, the central command processor may determine a probable fault location, a probable fault type, and a fault response.

A line state detecting apparatus provided in a balanced transmission system includes, in transmission lines comprising a pair of conductors W1, W2 connected to a transmitting portion 13, current transformers T11, T12 primary sides of which are inserted to respectives thereof in series therewith and secondary sides of which are connected in series to cancel currents or voltages of the two transformer by each other, and a detecting portion 11 for detecting currents or voltages on secondary sides of the current transformers T11, T12. By an output of the detecting portion 11, a difference of currents or voltages of the conductors W1, W2 of the transmission lines is provided and an unbalance component between the conductors W1, W2 is detected.

A PeakPower Energy Management and Control System having one or more roll-lock snap-on current transformer power monitoring devices, each to avoid interrupting power when installing current and / or power monitors. Each roll-lock snap-on current transformer power monitoring device may be snapped onto existing power wires inside a power panel or near equipment being monitored without disconnecting any wires or turning off power. Each roll-lock snap-on current transformer power monitoring device may be utilized in standalone mode as well as within a PeakPower Energy Management and Control System in accordance with disclosed embodiments. Each roll-lock snap-on current transformer power monitoring device may communicate via the power lines (Power Line Controller) or communicate via wireless using an integrated microprocessor based RF transceiver.

A system and method for performing diagnostics on a device, such as an appliance, using a sub-meter device that measures power characteristics related to usage of the appliance within a HEM network and provides such data to a home energy controller or the like. The sub-meter device can include one or more sensors, such as a current transformer, Rogowski coil, shunt resistor, or hall effect sensor, for collecting data relating to at least one of real power consumption, reactive power consumption, line frequency, line voltage, power factor, leading / lagging voltage-current comparison, and apparent power, etc.

A synchronous full bridge rectifier is controlled to provide a power factor near unity. The full bridge rectifiers are transistors each with a controlling input. The AC input signal and currents within the circuit are sensed and sent to a controller. In response, the controller output control signals to turn on / off the rectifying MOSFETS on a timely basis to form a power factor of near one with respect to the AC input signal. The full wave rectifier is made of N-channel MOSFET's, some with fast body diodes. The MOSFET's are rectifiers and PFC control elements. The result is a one stage synchronous rectifier with PFC. A solid state precision analog differential amplifier senses the AC line waveform and high frequency current transformers sense the currents. The controller accepts the inputs of the amplifier and the sensed currents and outputs control signals that turn on and off the four MOSFET's. The timing of turning on / off is arranged so that the current drawn from the AC source is sinusoidal and matches the phase of the sinusoidal AC source.

A step-down constant-current transformer including a controllable switch downstream from the one input and connected in series to a choke, a capacitor connected in parallel at the output, and upstream from the choke, a second controllable switch in parallel. Both controlled switches are MOSFET transistors. A control unit, in particular a pulse-width control unit, is provided for the MOSFET transistors. The voltage across the parallel-connected MOSFET transistor is monitored to determine whether a reverse current, i.e., a current flowing through the choke from the output in the direction of the input of the constant-current transformer, or an electric potential at the center tap of the half-bridge formed by the two MOSFET transistors is detected. For this purpose, a comparator and an AND circuit are provided, which, in the event of such a reverse current, block the parallel-connected MOSFET transistor to prevent the reverse current.

The invention provides a novel battery energy-storage system and a function integration designing method thereof. The system comprises an energy storage unit and an EMS (energy storage monitoring system); the energy storage unit comprises an EB (energy storage battery unit), an BMS (battery management system) and a PCS (power storage current transformer); the EB is connected with the BMS, the BMS is respectively connected with the EB and the PCS, the input end of the EMS is connected with the output end of the BMS, and the PCS and the EMS are communicated with each other. The method comprises an energy storage battery monitoring and analyzing method achieved through the BMS and the PCS and an energy-storage system monitoring and analyzing method achieved through the PCS and the EMS. In the battery energy-storage system function integration design provided by the invention, all large application occasions of electric power systems are covered, the objective is clear, and various requirements and applications are met.

A system and method of monitoring a plurality of electrical assets comprise an electricity distribution infrastructure, including a plurality of electrical asset sensors coupled to the electrical assets for monitoring an operating condition of the electrical assets as well as any fault conditions. The sensors may include a current transformer for obtaining a current waveform, a GPS receiver for applying a synchronized time-stamp to the waveform data, and a mesh network radio for transmitting the time-stamped waveform data. Data from the plurality of sensors may be encrypted and transmitted over a mesh network to one or more gateways that are in communication with a central command processor. In response to an abnormal operating condition of any electrical asset, the central command processor may determine a probable fault location, a probable fault type, and a fault response.

A current transformer includes a Rogowski coil, having an opening at the center in which a conductor penetrates, comprising, a printed circuit board having a plurality of layers forming at least first to fourth circuit board surfaces including a circuit board top surface, a circuit board bottom surface and circuit board conducting internal surfaces between the circuit board top surface and the circuit board bottom surface, a plurality of radial metal foils, each metal foil radiating from a center that is approximately the center of the opening, mounted on the first to fourth circuit board surfaces, a first winding formed by electrically connecting metal foils on the first and second circuit board surfaces with first plated through holes penetrating the first and second circuit board surfaces in a thickness direction of the printed circuit board, a second winding formed by electrically connecting metal foils on the third and fourth circuit board surfaces with second plated through holes penetrating the third and fourth circuit board surfaces in a thickness direction of the printed circuit board, a first return circuit line electrically connected with the first winding in series, a second return circuit line electrically connected with the second winding in series, and a pair of the first winding and the first return circuit line and a pair of the second winding and the second return circuit line being electrically connected in series.

Apparatus and method for measuring current drain and reporting power consumption using current transformer with primary windings made of low ohmic alloy, enabling the use of the secondary coil to power the sensing and reporting circuits eliminating the power wasted by AC-DC power adaptors used for the current sensors. The saving is substantial as the current sensors will not drain a current when the AC outlets are disconnected from a load or when the load is switched off. The apparatus using low ohmic alloy is extended to the structuring of terminals, including power pins, power sockets and combinations to provide a low ohmic sensing elements in AC plugs, outlets, adaptors and extension cables with multi outlets, dissipating the heat from the sensing elements by the plugs and the larger metal heat dissipation.

The invention relates to an evaluation system of transformer state based on multisource information integration and an evaluation method thereof, wherein, the evaluation system in the invention is composed of an oil chromatographic analysis subsystem, a partial discharge ultrahigh frequency signal detection subsystem, a winding deformation vibration signal detection subsystem, a current transformer detection subsystem and a computer; the technical point of the evaluation method in the invention lies in evaluating the running state of a detected transformer by fusing the detection results obtained by the detection methods utilized by the four detection subsystems by utilizing a D-S evidence theory fusion evaluation algorithm. The beneficial effects of the invention lie in being capable of timely discovering and accurately judging the malfunction of transformer and comprehensively reflecting the running state of a transformer.

The system makes it possible to monitor various electrical variables by using a simple structure at low cost with ease and with high reliability by a circuit breaker which jointly includes a current transformer to detect current, a transformer to detect voltage, and a zero-phase current transformer to detect leakage current, in addition to the switch controller to perform the basic function of the circuit breaker. Moreover, the system also provides a function to display various measured values, obtained as described above, by a display unit that can be detached and installed separately from the measuring section to display data sent in digital form by data transmission.

The current transformer comprises at least two partial circuits (CBn) each comprising a Rogowski type winding (Cn), each of said the partial circuits being made in the form of an angular portion of a complete circuit (CB) which surrounds at least one primary conductor (10, 10A, 10B, 10C) of the transformer over 360°. The winding (Cn) of each partial circuit (CBn) is constituted by a go winding (Cn0) and by a return winding (Cn1) which extend over the angular extent (θn) of the partial circuit (CBn). For each partial circuit (CBn), the go and return windings are electrically connected in series, both having turns wound in the same direction so as to form a single winding (Cn) which presents a pair of adjacent electrical terminations (T1n, T2n) connected to an acquisition system (7, 7′).

A high-precision Rogowski current transformer, the Rogowski coil is realized in a single printed circuit board while maintaining both the outside field rejection of a traditional Rogowski coil, and the increased output voltage similar to the multiple printed circuit board Rogowski coil arrangements.

A current transformer includes a Rogowski coil, having an opening at the center in which a conductor penetrates, comprising, a printed circuit board having a plurality of layers forming at least first to fourth circuit board surfaces including a circuit board top surface, a circuit board bottom surface and circuit board conducting internal surfaces between the circuit board top surface and the circuit board bottom surface, a plurality of radial metal foils, each metal foil radiating from a center that is approximately the center of the opening, mounted on the first to fourth circuit board surfaces, a first winding formed by electrically connecting metal foils on the first and second circuit board surfaces with first plated through holes penetrating the first and second circuit board surfaces in a thickness direction of the printed circuit board, a second winding formed by electrically connecting metal foils on the third and fourth circuit board surfaces with second plated through holes penetrating the third and fourth circuit board surfaces in a thickness direction of the printed circuit board, a first return circuit line electrically connected with the first winding in series, a second return circuit line electrically connected with the second winding in series, and a pair of the first winding and the first return circuit line and a pair of the second winding and the second return circuit line being electrically connected in series.

The invention relates to a control system of a flexible wind power DC convertor on the sea, which pertains to the technical field of power transmission in wind power generation and comprises the doubly closed loop control structure of a sending end rectifier on the sea and the doubly closed loop control structure of a receiving end inverter on the coast; the doubly closed loop control structure of the sending end rectifier on the sea is used for controlling the active power of a flexible DC transmission system and the voltage stability of a wind power AC system; the doubly closed loop control structure of the receiving end inverter on the coast is used for controlling the constant voltage of the DC side of a receiving end convertor and the dynamic regulation of the reactive power of the main network accessing end of the receiving end convertor; two control structures are mutually independent and no data communication exists between the two control structures. The control system can fast and correctly control the active power of wind power transmission on the sea as well as promote the stability of the wind power AC system on the sea and the transmission efficiency and the power quality of the whole DC transmission system.

The data storage and processing resources required for an electric meter are reduced by basing the selection and application of phase error correction on a root mean square load current flowing through the meter.

There is provided an inductive power line data coupler. The coupler includes (a) a magnetic core having a high magnetic permeability at a data communication frequency and being configured to allow a power line of a power distribution system to be routed through the magnetic core to serve as a primary winding, (b) a data signaling circuit that provides a secondary winding through the magnetic core for coupling a data signal between the power line and a communication device, and (c) a choke coil coupled to the data signaling circuit for creating a flux-canceling power frequency current opposite in direction and comparable in magnitude to a power frequency current. The coupler may also include a circuit for sensing a level of current in the power line.

A pick-up is provided for an Inductively Coupled Power Transfer (ICPT) system having a parallel tuned resonant pick-up circuit. The pick-up has a plurality of independently controllable power supply outputs. This allows a first output to supply a high voltage load (e.g. 300V-550V) and one or more additional outputs for supplying other loads such as control circuitry which may only require 24V. The one or more additional outputs may be supplied via a current transformer connected in series with the resonant pick-up circuit. Control for each output may be achieved by partially or completely decoupling the pick-up from a primary conductive path of the ICPT system.

The invention discloses a serial arc-fault circuit interrupter, comprising a power circuit, a current sensor, a current sensing circuit, an amplifying and filtering circuit, a voltage zero-crossing comparison circuit, a microcontroller, a trip trigger circuit. A current transformer collects current signals in a circuit; the current signals are converted into voltage signals through the current sensing circuit, and are input into the microcontroller through the amplifying and filtering circuit; the voltage zero-crossing comparison circuit inputs a voltage zero-crossing pulse signal into the microcontroller; the microcontroller judges arc emergence through arc characteristics analysis and is disconnected with a load circuit by the trip trigger circuit. The protection method transforms a one-dimensional time signal into a two-dimensional time signal by utilizing short-time Fourier transform, analyzes changes of fundamental component, even-order harmonic and odd harmonic component of eachcyclic wave, extracts and judges the serial arc-fault characteristics. The method has the advantages that multiple characteristics are extracted to realize comprehensive judgment of fault arc, missedtrip and balk generated in serial arc detection in small load are prevented, and the reliability of judgment is improved effectively.

The invention discloses a charged test method for a current transformer and application thereof. The method comprises the following steps of: serially connecting a charged analyzer with a secondary low-voltage loop to serve as a test loop through two switches of a secondary terminal box on a secondary side loop of the current transformer under the condition of operating the charged current transformer; injecting a different-frequency test signal generated by the analyzer into the test loop through the analyzer, and realizing a charged error test and a charged frequency response test by measuring and calculating loop key parameters under an injected frequency signal; and changing a method for secondary load impedance to change excitation conditions through the analyzer, and measuring load change influence to test a charged exciting characteristic curve. Compared with the prior art, the method has the advantages that: the charged test of the current transformer can be performed without contact of primary voltage, an upward current source, a standard transformer or a load box, the safety and reliability of an uninterrupted power test are guaranteed, the equipment is high in integration, portable and light, and the method is favorable for on-site and laboratory tests and long-term online monitoring.

The invention relates to a battery energy storage system based power conversion system and a control method thereof. The power conversion system comprises a battery energy storage system, a bidirectional DC / DC (direct-current) converter, a grid-side current transformer, a filter circuit and an isolated voltage transformer. The battery energy storage system is in parallel connection with a direct-current bus of the grid-side current transformer through the bidirectional DC / DC converter; the grid-side current transformer, the filter circuit and the isolated voltage transformer are connected in sequence; and the isolated voltage transformer accesses to a power grid. The control method includes sequentially monitoring the battery energy storage system, the bidirectional DC / DC converter, the grid-side current transformer, the filter circuit and the isolated voltage transformer by a control circuit. Since the battery energy storage system utilizes battery cells connected in series and is in parallel connection with the common direct-current bus through the bidirectional DC / DC converter, circulation among battery packs is avoided, and capacity expansion of the system is facilitated. Further, by the aid of the monitoring control strategy for SOC (super capacitor state of charge) of the battery energy storage system and battery end voltage, excessive charge or discharge state of the battery energy storage system is avoided, service lives of the battery packs are prolonged, and comprehensive service cost is lowered.

The size of a status indicator for monitoring a current in a power cable is reduced by integrating a bobbin for the secondary winding with a current transformer core and integrating a circuit board including output terminals with a current transformer assembly.

The invention discloses a double-shaft fluxgate current sensor of the invention, relating to a device for measuring the current, comprising a fluxgate detecting probe, a zero flux current transformer and a signal processing circuit, wherein the fluxgate detecting probe is composed of two inner annular magnetic cores a and b, an excitation winding and an induction winding, wherein the fluxgate detecting probe is composed of an outer annular magnetic core and a secondary side winding; two inner annular magnetic cores a and b and the outer annular magnetic core are wound via a feedback winding; the signal processing circuit includes an exciting circuit and a detecting circuit, wherein the exciting circuit includes an exciting signal generating circuit, a voltage comparer and a power amplifying circuit; the detecting circuit includes an RLC resonant circuit, a differential amplifier circuit, a bandpass filtering circuit, a phase sensitive detecting circuit, a differential smooth filteringcircuit, a feedback circuit, a voltage controlled current source and a sampling resistor. The invention eliminates the measurement error of the current fluxgate current sensor by means of a closed loop formed by the feedback winding.

The invention discloses an opening current transformer capable of being installed in a powered-on mode. A shell is divided into two oppositely-connected half cylinders used as a movable semicircular shell body and a fixed semicircular shell body. The two shell bodies are hinged at one oppositely-connected position. A longitudinally-extending movable beam is arranged at an opening of the movable semicircular shell body. A longitudinally-extending fixed beam is arranged at an opening of the fixed semicircular shell body. The fixed beam and the movable beam are blocky bodies and make contact with each other when the two shell bodies are oppositely connected. The contact face of the movable beam and the contact face of the fixed beam are each provided with a longitudinally-extending notch. An upper piercing wire card is arranged in the notch of the movable beam. A lower piercing wire card is arranged in the notch of the fixed beam. The upper piercing wire card and the lower piercing wire card are oppositely connected to form a wire holding hole. The upper piercing wire card and the lower piercing wire card are each provided with metal teeth piercing a bus metal core. The opening current transformer further comprises an opening and closing mechanism making the upper piercing wire card and the lower piercing wire card opened or closed. The opening current transformer is reliable in insulation, capable of being firmly installed on a bus, and capable of being widely applied to occasions for measuring primary current and temperature of the bus.

A control apparatus of a single-phase power converter for a photovoltaic power generation system is disclosed, including a POS MPPT controller for calculating a rating current by applying a POS MPPT control method to an output current detected through a current transformer of a single-phase AC filter, a bandpass filter for filtering only signals of a low-frequency band from a load, a single-phase reference current generator for producing a reference current by matching a phase of the current from the POS MPPT controller to a phase from the bandpass filter, a single-phase current subtractor for subtracting an output current of a current transformer from the reference current calculated by the single-phase reference current generator to thereby calculate a difference current between the output current of the current transformer and the reference current, a PI controller for outputting a control signal, corresponding to the difference current from the single-phase current subtractor, to a PWM signal generator, and the PWM signal generator for generating a PWM phase control signal corresponding to the control signal from the PI controller.

In a digital branch circuit monitor, compensation for the phase error is accomplished by selecting a voltage sampled at a time temporally offset from the sampling time of the current by an interval quantifying the phase shift of the secondary current relative to the primary current that is characteristic of a current transformer.

A composite electric circuit breaker, and method thereof, is configured to detect signals regarding arc faults, overcurrent, and earth leakage. Arcs and electric currents are detected by a current transformer and earth leakage is detected by a zero phase current transformer. A variation of electric current, the number of arcs which are generated per a unit time, a present electric current value, and electric current earth leakage are combined to judge whether arc faults occur to then interrupt an electric power supply. Temperature is measured on a printed circuit board, and if temperature rise occurs, the electric power supply is interrupted, and an interruption cause is displayed. Electric accidents and occurrence of fires are prevented simultaneously and more accurately. The interruption causes can be confirmed, analyzed and externally monitored through a network, to thus maximize efficiency of electric management.