286 results about "Electric power quality" patented technology

An electronic electric meter for use in a networked automatic meter reading environment. The electric meter retrofits into existing meter sockets and is available for new meter installations for both single phase and three phase electric power connections. The meter utilizes an all electronic design including a meter microcontroller, a measurement microcontroller, a communication microcontroller and spread spectrum processor, and a plurality of other communication interface modules for communicating commodity utilization and power quality data to a utility. The electric meter utilizes a modular design which allows the interface modules to be changed depending upon the desired communication network interface. The meter measures electricity usage and monitors power quality parameters for transmission to the utility over a two-way 900 MHz spread spectrum local area network (LAN) to a remotely located gateway node. The gateway node transmits this data to the utility over a commercially available fixed wide area network (WAN). The meter also provides direct communication to the utility over a commercially available network interface that plugs into the meter's backplane or bus system bypassing the local area network communication link and gateway node.

There is provided an intelligent electronic device for responding to user data and information requests regarding power usage and power quality for any metered point within a power distribution system. The intelligent electronic device includes a first network interface which receives client side information and data requests, which are processed in accordance with a network protocol and forwarded to a network interface via a network socket interface translator which translates management signals to facilitate the eventual data transfer. Protocol routines process the requests by constructing an internal data request in certain cases and forwards the internal data request to a data interface for translation from an internal data request format of the protocol routine format to a native database format. The database receives the translated request, and retrieves the requested data from a measuring unit of the electric power meter, and forwards the data back to the requesting client.

This invention relates to an anti-theft alarm for electric power cable. Wherein, connecting an ac large-resistance inductance in series at least on two wires ends; arranging a dc detection power on wire supply end to form detection port with wire testing circuit with output linked to an alarm circuit; and connecting the detection port to wire on power supply end. This invention simplifies circuit to reduce cost and increase reliability, and brings benefit to treatment in time and loss reduction.

A composite power quality indication generated from user weighted statistical contributions of selected system parameters provides an overall indication of power quality in an electric power distribution system. The user defined weightings are maintained over time by continually updating sensitivities that normalize the component contributions to the composite power quality indication. The current composite power quality indication is displayed in relation to its long-term mean and to dynamic thresholds determined as multiples of the standard deviation of the long-term mean.

A multi-object comprehensive control energy conservation method of a subway power supply system fully recovers and utilizes the braking energy, and overcomes the shock to the electric network caused by the energy fed back instantaneously through part of the absorbed energy and the feedback energy. When energy is required for starting or accelerating the train within the power supply section, two parts of circuits are comprehensively controlled to release the excessive electric energy with the aim of maintaining the basic electric energy storage of the independent condenser banks. During the running process of the trains, the advanced algorithm is adopted for reasonable energy distribution, thereby achieving the purpose of the optimal performance of the entire system, improving the utilization factor of the recovered energy and enhancing the energy conservation effect. The control system further detects the harmonic wave and the reactive component of other non-traction load of the traction substation, triggers an AC/DC converter module to compensate for the harmonic wave and the reactive component of the part, and avoids the pollution of the electric network so as to further reduce the loss caused by the harmonic wave and realize the control of the multi-object comprehensive energy conservation.

The invention provides a composite energy storage system, which consists of a supercapacitor and a storage battery, wherein the composite energy storage formed by the supercapacitor and the storage battery has both power type and energy type characteristics; through the combined use, the charging and discharging times of the storage battery can be effectively reduced; in addition, the utilization rate of the energy storage system can be improved. According to an energy management and control optimization method matched with the composite energy storage, the total power of the composite energy storage is distributed through a low-pass filter, so that the supercapacitor and the storage battery respectively share a high-frequency component and a low-frequency component in the fluctuating power; through the two-way DC/DC1 converter constant-power control on the storage battery, the two-way DC/DC2 converter constant bus voltage control on the supercapacitor, and control strategies of the two-way DC/AC converter, the network loss of a power distribution network is reduced; the utilization efficiency of new energy sources is improved; the power fluctuation during micro power grid interconnection is effectively inhibited; the electric energy quality of a region electric network is improved; in an offline state, the stability of the voltage and the frequency of a micro power grid system can be ensured; the power balance generated during grid connection/off-grid switching is fast compensated.

Various examples are provided for power quality of service optimization for microgrids. In one example, among others, a microgrid includes a smart meter configured to control supply of electric power to loads based at least in part upon energy consumption scheduling of the loads, which is based at least in part upon an effective electric generation capacity associated with the microgrid. The energy consumption scheduling can be based at least in part upon estimated power output of a sustainable energy resource of the microgrid and a load demand characterization of the loads. In another example, a system comprises a plurality of microgrids and an advanced metering infrastructure (AMI) configured to monitor operations of the microgrids and to control supply of electric power from sustainable energy resources and energy storage systems to loads of the microgrids via smart meters based at least in part upon energy consumption scheduling of the loads.

The invention discloses an energy storage grid-connected circuit based on lithium batteries and a super capacitor and a control method thereof in the technical field of power equipment design, which is used for solving the problems that the electric power quality, the reverse current, the power random fluctuation and the like of a power grid are influenced by the grid connection of a distributed power supply. The energy storage grid-connected circuit comprises a lithium battery pack, a bidirectional power translation circuit, a super capacitor array, an inverter circuit, a filtering and grid-connected circuit and a three-phase AC (alternating current) breaker, which are connected in sequence. The control method comprises the following steps: controlling the bidirectional power translation circuit to discharge the lithium battery pack when a power-grid side needs power compensation and the lithium battery pack is in a normal working voltage state; controlling the inverter circuit to output power needing be compensated; and controlling the bidirectional power translation circuit to charge the lithium battery pack when the power-grid side has surplus power. According to the invention, when the distribution power supply generates random power fluctuation, the surplus power is stored, and electricity is supplied to the power grid properly when the power grid needs power compensation.

Time-domain characteristic of voltage signal is analyzed due to the methods of voltage quality monitoring based on time-domain analysis and automatic classification method of disturbance; four characteristic quantities used for classifying disturbing signal of electric power quality are extracted; an automatic classification method for disturbance of electric power quality is given out based on the four characteristic quantities. The method can conclusively and automatically identify the disturbing signals of electric power, such as a harmonic wave, an inter-harmonic wave, a wave and flickering, under voltage, overvoltage, oscillation transient voltage, voltage swell and sag, momentary interruption, and the like, and mixing disturbing signals from voltage signals. The generation time can be identified and strength of the disturbing signals can be evaluated. The method is little in calculated amount, which can be realized with single chip DSP, thus especially being applicable to on-line monitoring of voltage quality. Disturbing signal of various electric power qualities and the mixing disturbing signals can be automatically identified from a plurality of recorder data of substation busbar voltage, the generation time can be identified and the strength of the disturbing signals can be evaluated.

The invention discloses an electric power system data reconfiguration decompressing method based on orthogonal matching pursuit. A compressed sensing theory is adopted for conducting parallel data compression of sampling and compression on an electric power quality signal. The method includes that first, a line with the largest correlation with margin is selected in a sensing matrix, and simultaneously a selected space is updated. By solving a least square problem, residual is guaranteed to be minimum, sparse vector elements are obtained, then, the residual is updated, selected lines in the sensing matrix are removed, and finally sparse elements are obtained through loop iteration. By means of the method, the compressed sensing theory is adopted for conducting sparse decomposition on electric power quality data, then gauss measuring coding is conducted on sparse signals, and finally a signal is reconfigured through an orthogonal matching pursuit algorithm. The method breaks through a traditional data compression method framework of first sampling and then compressing, sampling and compression are conducted parallelly, a small amount of sampling can recover an original electric power quality signal well, a requirement for hardware is reduced, and compression efficiency is improved.

An apparatus includes an upstream/downstream probability module that determines, for each measurement point in an electrical power system, an upstream/downstream probability. The apparatus includes a zone module that identifies a plurality of zones within the power system and an upstream/downstream module that identifies, for each measurement point and for each zone, if a power quality event in a zone is upstream or downstream of a measurement point. The apparatus includes a zone probability module that determines a zone probability for each zone by multiplying the upstream probability or the downstream probability for each measurement point. The zone probability is a probability that the event happened in a zone. The zone probability module uses the upstream probability of a measurement point when the zone is upstream of the measurement point and uses the downstream probability when the zone is downstream of the measurement point.

A distributed electric power generation system is configured to include a plurality of electric power distribution stations operable to receive electric power from an external power source and generate electric power in a balanced manner, a power transmission grid network connected to the plurality of electric power distribution stations for supplying received electric power to a plurality of demand loads using electric power, and a control station operable to acquire information on an electric power distribution period used to calculate a period during which electric power supply is needed, acquire an amount of power supply demand to be supplied via the power transmission grid network during the period during which electric power supply is needed, the period being determined from the acquired information on the electric power distribution period, and select one or a required number of electric power generation facilities for supplying electric power to the plurality of demand loads at a low cost based upon a start and stop cost and a running cost of each of the electric power distribution stations in accordance with the calculated electric power distribution period and the amount of power supply demand.

The present invention provides a network voltage sag source positioning system. The system comprises a data parsing and synchronizing module, a data storage module, a stationing scheme generating module, a sag source positioning and calculating module, an application program interface module and a human-computer interface module, wherein the data parsing and synchronizing module, the stationing scheme generating module, the sag source positioning and calculating module, the application program interface module and the human-computer interface module are respectively in two-way connection with the data storage module, and data interaction is performed through the data storage module. According to the network voltage sag source positioning system, voltage sag data, a network topological structure and network parameters are read respectively from an electric energy quality monitoring system or monitoring terminal and a power data SCADA system, the positioning function is achieved through a sag source positioning algorithm, the positioning result can be used by electric power quality analysis personnel, and the positioning result can also be used for fault analysis and diagnosis and the like through interconnection and interflow of a power distribution automation system or a scheduling system.

The invention discloses a mixed induction type active electric power filter system. The mixed induction type active electric power filter system comprises a rectifier transformer, a filtering branch, a rectifier and the other filtering branch, wherein the other filtering branch comprises three passive filters and a voltage source inverter, the passive filters are connected to the voltage source inverter, the primary side of the rectifier transformer is connected to a three-phase power grid through connecting impedor, an epitaxy winding of the secondary side of the rectifier transformer is connected with the rectifier, and the passive filters are connected to three junction points between a delta winding and the epitaxy winding of the secondary side of the rectifier transformer in parallel respectively. According to the mixed induction type active electric power filter system, influence of frequency fluctuation of the power grid side and the high-capacity nonlinear load side on electric power filtering performance is eliminated; meanwhile, the problems that serious harmonic pollution, high additional loss of a master device, high vibration and noise, low system power factor and low system operation efficiency are caused by harmonic waves and idle work to an industrial power distribution and consumption system are effectively solved on the premise that electric power quality on the power grid side meets the national standard of China.

The invention relates to an electric power equipment detection algorithm based on a convolution neural network, comprising the following steps of (1) a labelImg tool is used for labeling the visible light image and infrared image of the electric power equipment, and obtaining the label about the electric power equipment in the image; (2) the images and device-level tags in the training set are inputted to the detection model of electric power equipment for training, and update the model parameters by using the gradient descent algorithm of driving quantity to back propagate; (3) in the testingphase, the prediction box is reduced by soft non-maximum suppression, and the prediction box whose confidence level is higher than the threshold value is outputted finally; (4) compared with the current power equipment detection methods, the algorithm can converge and obtain excellent detection performance without fine-tuning on the pre-training model, has excellent robustness for small power equipment, can effectively reduce the phenomenon of frame error and frame leakage, and has high detection accuracy and detection speed to achieve real-time processing.

The invention provides an error data identification method applicable to secondary equipment of a power supply system. The method comprises the following steps: if difference between two adjacent sampling values of the secondary equipment is greater than a preset threshold, then the current data are the error data, and the error data are discarded. The theory is as follows: firstly, as primary equipment of the power supply system has large inductance and capacitance, in the case of serious fault of the power supply system, the current value or voltage value of the power supply system does not suddenly changes but changes according to an exponential function curve; secondly, a mutual inductor of the primary system and an internal mutual inductor of the secondary equipment which are used for signal transformation have a maximum range limit, so the sampling value of the second equipment has a maximum value; and thirdly, if the sampled signal has frequency, the sampled signal has the frequency characteristics. The threshold of the permissible maximum sampling value difference can be set by integrating the three steps with the specific characteristics of the secondary equipment, such as amplitude corresponding to sampling point number and sampling conversion of each cycle.

The invention relates to a monitoring device, in particular to a system for monitoring and orientating an electric power quality pollution source in an electric network. The system provides the monitoring and the orientation of a voltage swell/dip pollution source in the electric network: a wavelet analysis method is used for the first time to capture the voltage swell/dip from the real-time voltage waveform, and as long as a corresponding transient course is monitored, the effective value change curve of the line current is monitored and whether the voltage swell/dip is related to the line is judged, thereby achieving the purposes of monitoring and orientation of the voltage swell/dip. Besides, the system further provides the monitoring and the orientation of a harmonic-wave pollution source and a flickering pollution source. The system realizes the function of the on-line orientation of the electric power quality pollution source for the first time, provides effective centralized processing for the power supply system, avoids the widespread propagation of the polluted signals, improves the power supply quality of the electric network, and provides the uniform standard and theoretical foundation for the solution of the electrical energy pollution source, thereby being of great significance to the technological development of the monitoring and the orientation of the pollution source in the electric network.

The invention relates to a hybrid energy storage wind/PV hybrid generation system based on a solid state transformer. The system comprises a wind driven generator, a photovoltaic array, the solid state transformer, a hybrid energy storage module, a power grid, and a control module. The solid state transformer is respectively connected with the wind driven generator, the photovoltaic array, the hybrid energy storage module, the power grid, and the control module. The control module is connected with the hybrid energy storage module. Compared with the prior art, the system obviously reduces system size and cost and improves a device utilization rate. Power fluctuation the system can be preferably restrained, power distribution reliability and electric energy quality of a distributed power supply can be improved, and the system can provide short-time energy support under conditions of low illumination intensity, low wind speed, or the like.