235 results about "Low voltage grid" patented technology

A smart electricity meter with a function of monitoring and protecting power failure comprises a metering chip, a leakage current sampling circuit, a phase current sampling circuit, a phase voltage sampling circuit, a CPU (central processing unit), a power module and a low voltage breaker. The leakage current sampling circuit is electrically connected with the metering chip which is mutually electrically connected with the CPU. The CPU is electrically connected with the low voltage breaker through a trip output port. The low voltage breaker is electrically connected with the CPU through a status acquisition interface. The invention further provides a power failure monitoring and controlling method of the smart electricity meter. The smart electricity meter has the advantages that the reliable power module for power failure protection and control is provided, various types of power failure warning and protection are provided, failure warning and failure protection for voltage, current, power and the like are achieved for power users, failure spots are prevented and isolated, economic loss and personal safety accidents due to failure of electric circuit equipment of the users are prevented and reduced, and reliability of low voltage grids is effectively improved.

The present invention provides an intelligent low-voltage distribution electricity monitoring system based on a wiring diagram. The system comprises: a terminal information collector configured to collect the real-time data of a device and/or line and send the real-time data through a wireless device; a monitoring center configured to receive, store and develop the real-time data of a remote control command and configured to analyze and arrange the real-time data; and a monitoring terminal configured to provide an editing interface and an editing tool to perform the wiring diagram scheme design and store and load the graphic files, perform electric data superposition through combination of the real-time data wiring diagram and further provide an operation interface for the electric data superposition wiring diagram. The intelligent low-voltage distribution electricity monitoring system based on the wiring diagram can visually, comprehensively and stereoscopically grasp the running state of a device, accelerate the reaction of the low-voltage grid accidents, enhance the discrimination accuracy of the low-voltage grid accidents, reduce the manpower risk and reduce the financial cost.

A system and method for providing extreme fast charging of electric vehicles that mimics the typical gas station experience while also supporting local grid energy management using a distributed network of extremely fast charging stations to form a large virtual resource for the grid. The system consists of a controller unit responsible for system operation tasks, a high-voltage battery pack capable of rapid discharge rates to support extreme fast charging, a cloud-based database to persist and manage system and network data, a DC electric vehicle outlet for providing charging, safety systems, and power electronic equipment configured to allow bi-directional flow of power between a local, low-voltage AC grid and the extreme fast charging station. The bi-directional capabilities of the power electronic circuits within the system allow the charging station to provide power resources, stored within the high-voltage battery pack, to help support local grid power consumption.

A lightning arrester device for protecting an electrical circuit connected to a low-voltage network against transient overvoltages includes a plurality of gas-type spark gaps each connected directly in parallel with each other across two common nodes. Each of the plurality of gas-type spark gaps individually has a surge current rating below a desired surge current rating of the device.

An intelligent low-voltage network comprehensive protection device comprises a moulded case circuit breaker, a power circuit, a leakage analog circuit, a leakage detection circuit, a leakage amplifying circuit, an over/under-voltage sampling comparison circuit, an overcurrent sampling comparison circuit, a tripping operating value parameter adjustment setting circuit, a singlechip U4, a liquid crystal display circuit, an action state alarm circuit, a 485 communication interface and an electric switching on and off control circuit. The device not only has the functions of protecting earth fault, leakage tracking, overload, short circuit, overvoltage, undervoltage, faulted neutral line and the like, but also has the comprehensive function of adjusting the leakage operating values and actuation time, overvoltage and undervoltage operating values, overcurrent operating value and the like in a multi-switching manner, also has the functions of displaying voltage, current, leakage and other data and failure alarming, and further has the network systematic management function of telemetering, telecommunication, remote control and other low-voltage networks.

The invention provides an off-grid wind power supply system based on gird power complementation. A first part of the system comprises a wind driven generator, a fan controller, a main inverter, a storage battery group I, a storage battery group II and a double-power-supply conversion switch I which are mutually connected, wherein the double-power-supply conversion switch I is connected with a load, and power is supplied to the load through the double-power-supply conversion switch I; a second part comprises a storage battery group II, a storage battery group I, a grid-connected inverter and a charge-discharge control switch which are mutually connected, wherein the charge-discharge control switch is connected with a computer control unit; and a third part comprises a low-voltage grid, a double-power-supply conversion switch I, a double-power-supply conversion switch II and the computer control unit which are connected mutually. The off-grid wind power supply system has the benefits as follows: the capacity of the off-grid wind driven generator can be selected according to quantity of loads and characteristics of a wind field, and the 'one with multiple' distributed wind power supply system is constructed; the system and the low-voltage grid realize complementary double-power-supply for the loads; and wind energy resources are used for supplying power for the loads as far as possible, and the power utilization cost of an enterprise is effectively reduced.

The invention relates to a combined automatic dirt removing device of a medium-lower-voltage power grid overhead line. The combined automatic dirt removing device is technically characterized in that the device comprises a locking body, a travelling module, a reciprocating movement module, a dirt removing module and an obstacle removing module, a wire is sleeved with the modules with the dirt removing module as the center, the reciprocating movement module, the travelling module, the locking body and the obstacle removing module are symmetrically installed on the two sides of the dirt removing module, control modules are arranged in the locking body and the obstacle removing module, and a power source module is installed in the locking body and connected with the corresponding control module to supply power to the control module. The combined automatic dirt removing device is reasonable in design, peculiar matter wound on the wire can be effectively removed, dirt attached to the surface of the wire can also be removed, automatic dirt removing of the medium-lower-voltage power grid overhead line is achieved, unnecessary trouble caused by manual dirt removing is avoided, and the dirt removing efficiency is greatly improved.

The invention provides a control method and system for a power electronic transformer. The method includes the steps that S1, an active current instruction value of the power electronic transformer is determined, and active power which the power electronic transformer needs to output is controlled; S2, a reactive harmonic current instruction value of the power electronic transformer is determined; S3, according to the active current instruction value and the reactive harmonic current instruction value, a recombination current instruction value of the power electronic transformer is determined; S4, the current of the power electronic transformer is detected; S5, the output current of the power electronic transformer is controlled to follow the recombination current instruction value through a current control algorithm. The power electronic transformer and a traditional transformer operate in a parallel connection mode, while the load active power is provided, the quality of electric energy of a low-voltage grid is adjusted, distribution network contamination is eliminated, and stability and power supply reliability of a power distribution system are improved.

The invention discloses an electric shock fault detection method based on leakage current instantaneous amplitude-phase product sum features, and the method organically combines discrete Hilbert transform with a break variable calculation method, and comprises the steps: firstly extracting the break features of the accumulated sum of leakage current instantaneous phase differences through employing the instantaneous phase of a power supply voltage as a reference standard vector; then, calculating the summed sums of the sudden increments of the instantaneous amplitudes of the total leakage current signals, and extracting the proportional characteristics of the abrupt change of the amplitudes of the adjacent periods of the sampling signals; finally, using the product and sudden change characteristics of the instantaneous phase and amplitude of the total leakage current signal transient process and the cumulative effect function of the technical instantaneous amplitude-phase characteristic information in the transient change process as the criterion of electric shock fault detection in the low-voltage power grid, and providing a new electric shock fault detection method. The technicalproblems of misoperation and low correct commissioning rate generally existing in a low-voltage current residual current protection device are solved.

The invention relates to a distributed photovoltaic power generation integrated control system. A low-voltage microgrid control terminal and a low-voltage power quality control device are accessed into a low-voltage grid, and a medium-voltage power quality control device and a medium-voltage distributed power generation control terminal are accessed into a medium-voltage grid. The distributed photovoltaic power generation integrated control system has the advantages that by means of the distributed photovoltaic power generation integrated control system, a distributed photovoltaic power supply serves as standby energy, power supply blockage can be alleviated, margin of a power distribution network is enlarged, power supply reliability is improved remarkably, controllable idle-work output capability is provided, busbar voltage level is maintained, voltage drop is alleviated, large-area power outage is avoided, and capacity of the existing power quality regulation device can be reduced remarkably when the distributed photovoltaic power generation integrated control system and the existing power quality regulation device of the power distribution network are combined to operate to perform idle-work regulation or harmonic wave inhibition.

The invention provides a control device for residual current in a low voltage power grid, and comprises a residual current controller, a zero line grounding detector, an overvoltage detector, a zero-sequence current detection controller, a time controller, an actuating member controlled by the time controller, and a load switch controlled by the actuating member, wherein the zero line grounding detector, the overvoltage detector and the zero-sequence current detection controller are connected with the time controller, which comprises a time relay; and the residual current controller comprises a potentiometer, a residual current relay, a closed contactor of the time replay in the time controller and a normally open contactor and a normally closed contactor of the residual current relay. The device has the advantages of scientific designing, low cost, high power supply reliability, and assurance of personal safety, and overcomes the shortcomings of the existing residual current protector, including frequently tripping and non-detectable line insulation during operation at the same time.

An embodiment of the invention provides a method for monitoring low-voltage power grid equipment. The method includes: setting up a low-voltage power grid equipment data base comprising graphic data and attribute data of the low-voltage power grid equipment; receiving low-voltage power grid equipment ID (identification) number inputted by a user; extracting corresponding graphic data and attribute data of the low-voltage power grid equipment from the low-voltage power grid equipment data base according to the ID number; associating the low-voltage power grid equipment according to a preset service mode; and revealing low-voltage power grid information to a client according to a monitoring request to facilitate monitoring, wherein the low-voltage power grid information includes graphic information, attribute information and associated information of the low-voltage power grid equipment. The embodiment of the invention further provides a system for monitoring the low-voltage power grid equipment. Using the method and the system for monitoring low-voltage power grid equipment can realize unified monitoring and management of the low-voltage power grid equipment in the whole power distribution substation and improve monitoring efficiency of the power grid equipment.

The invention relates to a method for transmitting data records (D1...n) between a central communication device (Z) and any number of terminals (X1...n). At least one data co-ordination device (E) ensuring the data transmission between the central communication device (Z) and the terminals (X1...n) is provided, said data co-ordination device receiving or forwarding data records (D1...n) transmitted over the first data transmission section (A) between the data co-ordination device (E) and the terminals (X1...n), and a second data transmission section (B) between the data co-ordination device (E) and the central communication device (Z), the first data transmission section (A) being part of a low-voltage network (PLC). According to the invention, priority steps (P1...n) are defined for the data records (D1...n) to be transmitted over the first data transmission section (A). A reference time span (T) is defined for the transmission of the data records (D1...n), and a determinable part (T1...n) of the reference time span (T), in which the first data transmission section (A) is provided for the transmission of data records (D1...n) corresponding to each priority step (P1...n), is associated with the respective priority step (P1...n).

The invention relates to a bidirectional DC/DC converter for transmitting energy between a high-voltage grid (HV) and a low-voltage grid (LV), comprising connections for a high-voltage battery (U_HV) and a low-voltage battery (U_NV). The converter comprises the following:—one or more transformers (1) for galvanically isolating the low-voltage grid (LV) from the high-voltage grid (HV), an intermediate circuit capacitor (C_ZK) in the high-voltage grid (HV),—electronic switches (D₁ to D₄, M₁ to M₄) for connecting and reversing the polarity of the coil of the transformer (1) on the high-voltage grid (HV) and on the low-voltage grid (LV),—a controller (2) for controlling the electronic switches (D₁ to D₄),—and a series inductance (W₁) in the low-voltage grid (NV). The series inductance (W₁) is designed as a discharge transformer (3) for discharging the energy stored in the series inductance (W₁), wherein a second coil (W₂) is connected in series to a discharge switch (S) and a diode (D), and the series inductance (W ₁) is discharged to the low-voltage battery (UNV) when the discharge switch (S) is activated. The invention additionally relates to a method for charging the intermediate circuit capacitor (C_ZK) of the converter to the high-voltage grid potential from the low-voltage battery (U_NV).

The invention relates to an accounting method for indirect carbon emission reduction generated by imbalance management of three-phase load of a low-voltage distribution network. The method includes: analyzing the additional loss generated in a low-voltage line by three-phase load imbalance of the low-voltage distribution network; analyzing the additional loss generated in a distribution transformer by the three-phase load imbalance of the low-voltage distribution network; and after implementing management measures for the three-phase load imbalance, based on an analysis conclusion of the additional losses, calculating the carbon emission reduction of the concerned low-voltage distribution network brought by the reduction of indirect carbon emission intensity due to reduced additional losses. The accounting method can be used for registering national voluntary emission reduction methodology, evaluating the effect of carbon emission reduction of the management measures for the three-phase load imbalance of the low-voltage distribution network, and providing technical guidance for the management of carbon asset of power grid enterprises; besides, the management of the operation and optimization of medium and low voltage power grids is enhanced, further improvement of the operation efficiency of the power grids can be promoted, the target of energy saving of the power grid enterprises can be realized, and the method is directly related to the economic benefit of the power grid enterprises.

The invention relates to an unbalance and reactive compensation control device for a low-voltage power grid. The control device comprises a data processing module, a CPU module and a communication module. Switching of a control capacitor bank is achieved with network loss as the control target. After the data processing module samples currents and voltages of the low-voltage power grid, the effective values of the collected currents and voltages, the active factor, the reactive factor, the power factor and the current unbalance degree are calculated according to the collected currents and voltages. The CPU module calculates compensation amount according to the deviation between the reactive power and the set value of the reactive power and the deviation between the current unbalance degree and the set value of the current unbalance degree, and outputs three-phase compensation and single-phase separate compensation switching control signals according to the compensation amount. The switching control signals are transmitted to a switching device of the capacitor bank, and the switching device carries out switching according to the switching control signals and compensates for the low-voltage power grid. According to the unbalance and reactive compensation control device, reactive compensation can be carried out, the three-phase current unbalance problem can be solved at the same time, and therefore the optimum compensation effect can be achieved.

The invention discloses a low-voltage reactive compensation cabinet. The low-voltage reactive compensation cabinet comprises a cabinet body, a cabinet body base, an upper cabinet chamber, a middle cabinet chamber and a lower cabinet chamber, wherein the upper cabinet chamber is connected with an upper cabinet door, the middle cabinet chamber is connected with a middle cabinet door, the lower cabinet chamber is connected with a lower cabinet door, and the top portion of the cabinet body is provided with a lightning rod at the same time. The low-voltage reactive compensation cabinet is compact in structure, novel in layout and low in cost, facilitates electric maintenance, and can enable a low-voltage power network to obtain reactive power compensation on an occasion with not high harmonic waves.

The invention relates to the field of power distribution automation, discloses a method and a system for rapidly responding to power-down faults of low-voltage power grid user lines and aims to rapidly respond to the power-down faults of the low-voltage power grid user lines, improve operation and maintenance efficiency and improve service level. The method comprises the following steps: detecting power-down faults in real time or obtaining power-down faults from an electric energy meter via an electric energy meter communication module, generating power-down fault information by using power supply of a spare power supply and sending the power-down fault information to a concentrator through a wired manner or a wireless manner after the faults are detected; sending the power-down fault information and self attribute information to a master station via the concentrator; analyzing the power-down fault information forwarded by the corresponding concentrator via the master station, starting remote meter reading of a target electric energy meter through a wired manner or a wireless manner according to analysis results, determining that the power-down fault information is valid if the meter cannot be read normally, and starting corresponding rush-repairing processes.

The invention aims at overcoming the prejudice of the prior art, and designs a scientific ultra-large-scale low-voltage data processing method, wherein the existing network architecture is utilized, thus data storage and retrieval are much facilitated, and abnormal data therein can be analysed in time; the missing of data is also avoided during the whole system running process. The technical scheme adopted by the ultra-large-scale low-voltage data processing method disclosed by the invention is as follows: the ultra-large-scale low-voltage data processing method comprises the steps of storing the whole database in a single file on a host machine, creating a cache for low-voltage grid data in a memory according to the belonged running unit of operating personnel, forming the subset of the whole low-voltage grid, and the like. The ultra-large-scale low-voltage data processing method disclosed by the invention belongs to an improvement on the traditional technology; with the adoption of the ultra-large-scale low-voltage data processing method disclosed by the invention, the minimum calculation unit can be effectively set; due to the manner of setting a spatial grid index and combining with an R-tree index, the efficiency of indexing is greatly increased and the calculation amount is reduced.

The invention provides a feeder automation simulation training system, which includes a power distribution master station, an EPON communication network, a power distribution terminal, and a feeder grid, and is characterized in that: the power distribution master station is provided with a simulation system microcomputer, and the simulation system microcomputer There are simulation system server software and power distribution SCADA, the simulation system server software includes feeder fault simulation software and a two-dimensional virtual feeder test module, and the two-dimensional virtual feeder test module includes a virtual operation learning module and a feeder operation test module; The feeder network frame includes a simulated ring network composed of outgoing busbars, outgoing line switches, feeder line switches, tie switches, low-voltage cables, and overhead lines. The present invention intensifies distribution automation system components scattered in geographical areas, lowers the primary network frame low pressure, has a simple and clear structure, can carry out debugging, testing and training of various feeder automation modes, and optimizes distribution automation operation and maintenance operation training and assessment way, reduce the risk of operation, test and assessment process, and improve the pertinence of distribution automation engineering training.

The invention belongs to the field of power equipment and discloses a community low-voltage grid integrated distribution box. The community low-voltage grid integrated distribution box comprises a box body, and the box body is prepared from perlite, sepiolite, borax, dolomite, brucite, an activating agent, aluminum oxide, serine, methacryloxypropyltrimethoxysilane, polypropylene resin, graphite, nano silicon carbide, polyolefin elastomer, polycarbonate, polyvinyl alcohol, isopropyl palmitate, tributyl phosphate and talcum powder. The community low-voltage grid integrated distribution box is excellent in mechanical property, insulating property, corrosion resistance and flame retardation and effective in prevention of damages, electric shock and fire disasters.