912results about "Phase sequence/synchronism indication" patented technology

A system and method for determining the relative phase of each of a plurality of load meters connected to a three-phase power distribution system. The system includes a gateway that communicates information to and from each of the individual load meters. The gateway generates a timing pulse that is received by each of the load meters. Based upon the delay from the receipt of the timing pulse to the next zero crossing of the single phase power supply received by the meter, the utility can determine the phase of the individual meter. The system can include a feeder meter connected to each phase of the electrical supply system to determine the energy consumption for each of the meters connected to a specific phase. The utility can compare the energy consumption information from the feeder meter to all of the load meters connected to the same phase to determine whether any energy theft is occurring.

A method and system for detecting and locating a single-phase ground fault on a low current grounded power-distribution network, comprising: respectively testing and picking up the voltage signals and current signals at multiple positions on each phase feeder (61), and determining the corresponding transient voltage signals and transient current signals according to the extraction of the voltage signals and the current signals (62); when the change in the transient voltage signals and the transient current signals exceeds a preset threshold (63), synchronously picking up the voltage signals and current signals at multiple positions on a three-phase feeder (64); calculating corresponding zero-sequence voltages and zero-sequence currents according to the voltage signals and current signals synchronously picked up at multiple positions on the three-phase feeder (65), and then extracting the steady-state signal and transient signal of the zero-sequence voltage and zero-sequence current at each position on the three-phase feeder (66); and determining a specific fault location on a faulty line according to the steady-state signal and the transient signal (67). The method effectively detects and displays a single-phase ground fault on a low current grounded power-distribution network.

A system and methods for optimizing the performance of communication network utilizing an electrical distribution grid are disclosed. Optimization methods may include archiving historical message data and metrics from transmissions by Remote Hubs received on one or more Substation-to-Edge channels. Trends in the archived metrics over time are later analyzed to determine which combination of transmission variables such as frequency band, modulation method, drive voltage, and transmission time produce the highest message success rates overall. The results of such analysis may be used to provide feedback to the Remote Hubs or reveal necessary repairs to the network. Optimization may also be carried out locally by an individual Remote Hub by estimating the impedance of the transmission medium and adjusting either drive voltage or transmission band.

A line phase identification system and method identifies the phase of a power line at a remote unknown-phase line (160) in a three-phase power distribution network (100). The instantaneous phase of a known-phase line (150) is measured and saved each GPS second using a 1-pps time mark of a GPS receiver (660). The instantaneous phase at the unknown-phase line (160) is measured at a single GPS second using the 1-pps time mark of a GPS receiver (660) and compared to the phase measurement taken from the known-phase line (150) at the same GPS second. The differential phase between these simultaneously taken known and unknown instantaneous phases will be close to either 0, +120, or −120 degrees, thus identifying the line phase at the line under test (160).

A system and method for inferring schematic and topological properties of an electrical distribution grid is provided. The system may include Remote Hubs, Subordinate Remotes, a Substation Receiver, and an associated Computing Platform and Concentrator. At least one intelligent edge transmitter, called a Remote Hub Edge Transmitter, may transmit messages on the electrical distribution grid by injecting a modulated current into a power main that supplies an electric meter. The Subordinate Remotes, Remote Hubs, the Substation Receiver, and the associated Computing Platform and Concentrator may contain processing units which execute stored instructions allowing each node in the network to implement methods for organizing the on-grid network and transmitting and receiving messages on the network. The Substation Receiver, Computing Platform and Concentrator may detect and infer schematic grid location attributes of the network and publish the detected and inferred attributes to other application systems including geospatial information systems maintaining the logical and physical network model.

Methods and systems are described for determining a phase of transmitted voltage. In one embodiment, a power distribution system may operate to transmit voltage and an injected signal. The system may also include a power meter that may receive the voltage and injected signal. The power meter may determine a phase of the received voltage based on the received voltage and the injection signal.

Provided is an electric energy meter phase identification method. The phases A, B and C of a general meter in a transformer area are used as reference. Correlation operation is carried out on the voltage values of a user electric energy meter at a plurality of moments and the voltage values of all phases of the general meter in the transformer area at the same moments. The phase is determined according to the highest correlation. As the phase can be identified accurately by measuring the voltage of an intelligent electric energy meter, there is no need for special tools to carry out identification on site, and the workload is reduced.

Phasor Measurement Units (PMUs) tend to be specialized and expensive—relegated to only key points in power distribution networks, and are generally reliant on GPS technology. The present disclosure details how any smart meter—using wireless communication—can perform sub-microsecond-grade synchrophasor measurements. Other aspects concern smart meter-based determination of A, B or C phase of the tri-phase power network. This can involve count-stamp enabling message packets sent to and/or from a smart meter, and then associating such count-stamps to local measurements of power phase by a metrology unit. Once a network of such enabled smart meters and other devices is formed, sub-microsecond metropolitan-wide and entire region-wide synchronizing time standard can calibrate local measurements of power phase, where simple A, B and C phase determination is one low hanging fruit application of such. Low cost aggregate monitoring of metropolitan-wide synchrophasors promises a next chapter of importance for that relatively recent art.

The invention discloses a shared-frequency asynchronous phase-checking method and belongs to the field of measurement. The method comprises the following steps of: generating a synchronous standard phase signal serving as a third-party reference by means of a commercial power network; sequentially acquiring a voltage phase signal between each phase of a system power supply and each corresponding phase of the to-be-checked power supply; performing phase comparison on the measured voltage phase signal and the third-party reference at the time to obtain a voltage phase differential value; comparing the voltage phase differential value between each phase of the system power supply and each corresponding phase of the to-be-checked power supply to obtain a comparison phase difference; and judging whether each phase of the system power supply and each corresponding phase of the to-be-phased power supply belong to the same phase or not according to the value range of the phase difference so as to obtain the conclusion whether the system power supply has the same phase as the to-be-phased power supply or not. The asynchronous phase-checking method can check phases of systems with the same or different voltage levels, can test whether a power supply loop has the failures, such as 'phase failure' and the like, or not, can check phases in different places and widens the application field of the routine phase-checking tests.

The invention relates to a nuclear phase method for a digital transformer substation, comprising the following steps: 1) in a digital transformer substation realized in a point-to-point mode, a nuclear phase device accesses high-speed serial communication data from different interval merging units, and sends the received communication data to a personal computer (PC), and the PC randomly selects one phase voltage as a standard and respectively and intuitively inspects the correctness of the amplitude and phase relation of each phase voltage of the same voltage class or different voltage classes, thereby completing secondary nuclear phase in the process of starting the digital transformer substation; and 2) in a digital transformer substation realized in a networking mode, the nuclear phase device accesses Ethernet communication data from different interval merging units by means of an IEC61850 switched network device, and then sends the communication data to the PC, and when carrying out voltage nuclear phase, the PC randomly selects one phase voltage as a standard and respectively inspects the correctness of the amplitude and phase relation of voltages of the same voltage class or different voltage classes.

A method and system for detecting and locating a single-phase ground fault on a low current grounded power-distribution network, comprising: respectively testing and picking up the voltage signals and current signals at multiple positions on each phase feeder (61), and determining the corresponding transient voltage signals and transient current signals according to the extraction of the voltage signals and the current signals (62); when the change in the transient voltage signals and the transient current signals exceeds a preset threshold (63), synchronously picking up the voltage signals and current signals at multiple positions on a three-phase feeder (64); calculating corresponding zero-sequence voltages and zero-sequence currents according to the voltage signals and current signals synchronously picked up at multiple positions on the three-phase feeder (65), and then extracting the steady-state signal and transient signal of the zero-sequence voltage and zero-sequence current at each position on the three-phase feeder (66); and determining a specific fault location on a faulty line according to the steady-state signal and the transient signal (67). The method effectively detects and displays a single-phase ground fault on a low current grounded power-distribution network.

The invention belongs to the technical field of electrics and relates to a three-phase alternating-current phase sequence detecting method and device thereof. The invention solves the technical problems of complicated phase sequence judging process, complicated judging circuit, high cost and the like of the prior art. The detecting method comprises the following detecting processes of: a, signal collection; b, signal processing; and c, phase sequence judging. The detecting device comprises an A phase sampling unit, a B phase sampling unit, a C phase sampling unit, a processor, a sequencing unit, a judging unit, an A phase sampling unit, a B phase sampling unit, a C phase sampling unit, an analog/digital converter and the like, wherein the A phase sampling unit, the B phase sampling unit and the C phase sampling unit are connected on three-phase electrical equipment or a three-phase alternating-current power supply to be used for collecting each phase of electrical signal. The invention has the advantages that a power grid cycle can reflect phase sequence states in real time at any moment, the phase sequence judging is timely and effective, and the electricity safety is improved; when the detecting device is applied to the field of digital control, a peripheral hardware judging circuit is effectively simplified; and the phase sequence detecting method is simple and practical and the detecting device has strong capacity of resisting disturbance.

A method and system for detecting and locating a single-phase ground fault on a low current grounded power-distribution network, comprising: respectively testing and picking up the voltage signals and current signals at multiple positions on each phase feeder (61), and determining the corresponding transient voltage signals and transient current signals according to the extraction of the voltage signals and the current signals (62); when the change in the transient voltage signals and the transient current signals exceeds a preset threshold (63), synchronously picking up the voltage signals and current signals at multiple positions on a three-phase feeder (64); calculating corresponding zero-sequence voltages and zero-sequence currents according to the voltage signals and current signals synchronously picked up at multiple positions on the three-phase feeder (65), and then extracting the steady-state signal and transient signal of the zero-sequence voltage and zero-sequence current at each position on the three-phase feeder (66); and determining a specific fault location on a faulty line according to the steady-state signal and the transient signal (67). The method effectively detects and displays a single-phase ground fault on a low current grounded power-distribution network.

The invention relates to a method for detecting positive sequence, negative sequence, idle and harmonic currents of a power supply system. The detection method is based on three-phase voltage space vector oriented positive sequence synchronous coordinate rotation transformation, negative sequence synchronous coordinate rotation transformation and low-pass filtering. The method is very effective for detecting various positive sequence, negative sequence, idle and harmonic currents of three-phase four-wire and three-phase three-wire non-linear circuits. The method only transforms the tested current, and does not need to transform voltage. Therefore, the invention has the advantages of simple structure and clear conception. The invention is the simplest engineering method for dynamic and static idle and harmonic compensation.

Systems, methods, and apparatus for utility meter phase identification are provided. A utility meter may receive, from a remote system, a plurality of reference signals for respective zero crossings for a plurality of phases in a multiple-phase power system. The reference signals may be generated utilizing a precision time source. The utility meter may also receive a precision time signal from a time source. The precision time signal may be utilized to time stamp a zero crossing of a voltage signal at the meter, and the time stamped voltage signal may be compared to the plurality of reference signals in order to determine a phase to which the utility meter is connected.

The invention provides an automatic detection and regulation method and an automatic detection and regulation circuit for an air conditioner. The circuit comprises a singlechip control circuit, a phase-sequence detection circuit, a relay driving circuit, a display circuit, a power supply circuit, a compressor overcurrent protection circuit, a relay contact adhesion detection circuit and a startup detection circuit. When the technical scheme is adopted, the power supply circuit provides a working voltage for the phase-sequence detection circuit, the display circuit, the singlechip control circuit and the relay contact adhesion detection circuit; the signals of the phase-sequence detection circuit, the relay driving circuit, the compressor overcurrent protection circuit, the relay contact adhesion detection circuit and the startup detection circuit are sampled and input into the singlechip control circuit; after the signals are processed by the singlechip control circuit, control instructions are output to a corresponding circuit to be executed; and the display circuit displays a phase-sequence output state and codes of various faults such as open phase, relay contact adhesion, relay operation failure, overcurrent and the like and gives a buzzing alarm, so that equipment faults caused by reversed phase, open phase or voltage unbalance are avoided.

The invention discloses a wire order test method for testing cable wire order. The method is as follows: a first N-path analog quantity switch selector is placed at the side of a cable to be tested, and a far-end loopback line is arranged; the far-end loopback line is respectively connected with resistors R1-RN in series, and the requirement of selecting far-end loopback resistors is that the sumof any two resistors is not equal; local 5 V high level is output through the line and then delivered to a far-end loopback passive joint; the 5 V high level is looped back to the local through the tandem resistors in the line and then through the tandem resistors on the other line; and because the sum of any two far-end resistors is not equal, the partial pressure value on any loopback line is not equal, thus the connection manner of the wire order can be judged. In the invention, a single port device is used to achieve measurement and the cost of the test device can be saved. By using the method, the measurement of any wire order can be realized. The method can be used in more occasions owing to the any wire order judgment function.

A multi-phase electrical power distribution network includes a substation; a signal generator for providing a different signal on each of a plurality of phases leaving the substation; and a signal discriminator for detecting each of the different signals at a consumer of the electrical power.

A long range wireless phasing voltmeter determines the phase difference between the time-varying voltage carried on a reference electrical conductor and another, field conductor. The voltage signal from the reference conductor is measured by a reference probe and compared by a first unit in communication with that reference probe to a precision 60 Hz signal generated from a GPS receiver. The phase difference between these, in the form of a nine-bit, audible signal using frequency shift keying to modulate the carrier frequency, is transmitted by the first unit to a second unit perhaps miles away. A receiver in the second unit decodes the signal and uses another precision 60 Hz signal generated from another GPS receiver to re-create a surrogate of the original reference voltage signal. This surrogate signal is forwarded to a meter probe that is measuring the signal on a field conductor. The meter probe can then compare the two signals to determine the phase angle difference between them.

The invention relates to a transformer area phase identification method based on synchronous sampling of a concentrator and an electricity meter. The concentrator is synchronized with a collector, theconcentrator and the collector do not include time delay almost, and thus, after that the concentrator issues an ordered sampling instruction to the collector, the concentrator and the collector start data collection in the same ordered sampling time point, and the accuracy of the transformer area phase identification is improved; three-phase voltage data, collected by the concentrator, of a master meter of a transformer area and voltage data, obtained by the concentrator from the collector, of the single-phase electricity meter are processed to obtain standard deviations of the voltage of the single-phase electricity meter relative to phases of voltages of the master meter of the transformer area, and the phase connected to the single-phase electricity meter is determined according to whether voltage fluctuation curves between the single-phase electricity meter and the three phases of the master meter of the transformer area are similar on the basis of the three standard deviations.The phase identification rate of the single-phase electricity meter in the transformer area can be improved.