323results about How to "Ensure power supply reliability" patented technology

The invention discloses a micro-grid multi-objective optimized operation control method, which comprises the steps of: constructing a micro-grid operation indicator function aiming at wind-light complementary and cold, heat and electricity combined supply micro-grid; then constructing a complete small signal model of the micro-grid for theoretical analysis to provide theoretical guidance for the multi-objective optimized operation control of the micro-grid; and finally on the basis of a multi-objective intelligent optimization theory, comprehensively using power system computer aided design (PSCAD)/electromagnetic transients including direct current (EMTDC) and MATLAB software to design the micro-grid multi-objective optimized operation control method, so as to enable the micro-grid to realize comprehensive optimization of multiple operation indicators such as economy, cleanness, reliability, stability, dynamic performance and the like in different operation modes such as a synchronized operation mode, a mode capable of being switched between the synchronized operation mode and an independent operation mode, an independent operation mode with sudden load change and a resynchronized operation mode.

The invention relates to an electric secondary AC circuit detection method which comprises the following steps: before a power plant machine set is started, a low-voltage short-circuit point or a short-circuit bogie is input; three-phase 380 V voltage is added at the high-voltage side of a booster station to form a circuit by means of the impedance of a transformer and a generator; current amplitude and phase are measured through a current detecting apparatus to check polarity and transformation ratio in advance; all current protective directions such as generator differential motion are measured. When a neutral point is not connected, a short-circuit point is made at a high plant transformer low-voltage side, and the three-phase 380 V voltage is added at the neutral point of the generator, thereby realizing overall checkup of a generator AC circuit; then, the three-phase 380 V voltage is converted into one-phase voltage or two-phase voltage to carry out overall checkup of a zero sequence circuit. The detection method can check all CT and PT circuits of a generation-transformer group before power transmission; moreover, all protection directions of the generation-transformer group are checked in advance, thereby saving time and fuel oil along with economical efficiency, environmental protection and safety. The electric secondary AC circuit detection method can check secondary circuits such as the transformer and the bus differential protection of a transformer substation.

The invention provides an on-line three-phase load unbalance processing method suitable for a low-voltage distribution network. The on-line three-phase load unbalance processing method comprises the following steps of: monitoring three-phase load by three-phase load monitoring units on the low voltage side of a distribution transformer, and transmitting monitoring data to three-phase load unbalance monitoring units of the distribution transformer; judging whether the three-phase load unbalance exceeds a standard value or not by the three-phase load unbalance monitoring units of the distribution transformer; if the three-phase load unbalance exceeds the standard value, transmitting signals to an on-line load phase modulation control unit by a communication unit; judging whether the three-phase load unbalance of the distribution transformer is caused by the three-phase load unbalance of a main low-voltage circuit or not by the on-line load phase modulation control unit; and if so, setting an on-line load phase modulation strategy according to the monitoring data of the load monitoring units of branches of three phases of the main low-voltage circuit, sending a control command to an on-line load phase modulation switch combination unit by an on-line load phase modulation judging and controlling unit, and switching the load phases of the branches of users so as to realize the on-line three-phase load unbalance processing.

Provided is a low voltage microgrid group independent coordination control system, employing a layered control structure, i.e., an equipment layer, a grid control layer and a group control layer. A microgrid group controller receives a scheduling instruction of a group level energy management system; based on the safety and reliability of a control target of the microgrid group and sub microgrids, the microgrid group controller controls exchanging power between a microgrid group and a power distribution network and each sub microgrid, grid disconnection or grid connection of the microgrid group, and grid connection or grid disconnection of the sub microgrids, realizes interface control between the sub microgrids and the microgrid group, and meanwhile issues a control instruction to a grid level controller. The grid level controller works out optimal control strategies of distributed power supply, energy storage and load, and realizes stable operation and smooth transition among states of the sub microgrids in a grid connection state, and information communication with the microgrid group controller. A supply or energy storage local controller completes primary regulation of frequency and voltage of distributed power supply and energy storage; a load controller completes load grading control.

The invention discloses an integrated power grid optimization auxiliary decision analysis system comprising an external data server, a system database, a data extraction service module, a data transformation service module, a data management service module, a graphics generation engine module, a graphics editing engine module, a topological analysis engine module, a grid rack data management module, a grid rack analysis evaluation module, a grid rack optimization management module and a business expansion auxiliary decision module. According to the integrated power grid optimization auxiliary decision analysis system, a whole network contact map of power grid racks is generated, the existing grid racks are analyzed by utilizing grid rack device data and real-time operating data, operations are carried out on the whole network contact map to simulate optimization, change and business expansion access of the grid racks, and the simulated grid racks are analyzed for solving the problem that various technical specifications, typical design guidelines and the like are not effectively applied to construction and renovation of a power grid so that the construction and the renovation of the power grid have blindness and the problems of insufficient analysis to the current situation of the power grid by a business expansion access scheme and unreasonable selection of an accesses point.

The invention relates to a self-adaptive auto-switching scheme for standby power supply of an incoming circuit breaker of a transformer station. Breakers for standby auto-switching in the present power system are divided into a power type and an intermediate interconnection type. The self-adaptive auto-switching scheme for standby power supply is characterized in that self-adaptive standby switching function of standby auto-switching units can be achieved by adopting four work manners no matter what the main wiring manner of transformer station with a voltage level of 110 kV or less is; four standby auto-switching work manners can be selectively switched and the primary connection manner of a voltage transformer can be determined through protection value setting; and the state of an interconnection circuit breaker can be determined through value setting and external pressplate switching. The novel scheme can maximally reduce the alteration cost of the present equipment, and has application and popularization values. The standby self-switching unit adopting the scheme can self-adaptively operate under the different wiring manners and different operation manners without being operated by operators, thereby ensuring the power supply reliability.

The invention relates to the technical field of electromobile charging, particularly to an electromobile charging system based on new energy application and a control method thereof. An electromobile charging station micro-grid system is composed of a new energy power supply system, a reserve diesel power supply system and an energy storage system. The new energy power supply system includes one or more of a photovoltaic power supply system, a wind power supply system and the like. The electromobile charging station micro-grid system is controlled by an intelligent control system, in case of normal mains supply, the new energy power supply system is subjected to networking operation with mains supply to power electromobile charging piles in the manner that the new energy power supply system is a priority; in case of mains supply outage or failure, connection with the mains supply is cut, and the electromobile charging piles are power by the new energy power supply system, the diesel power supply system and the energy storage system. In this way, power pressure, caused by additional power load capacity of the electromobile charging station, is balanced, an intelligent electromobile charging system safe, reliable and free of noise and pollution is established, and the electromobiles are charged in the energy-saving and emission-reducing manner.

The invention relates to an intelligent household microgrid system based on a technology of internet of things. The intelligent household microgrid system includes an energy system and a control platform thereof. The energy system includes a photovoltaic cell, a chopper module, an energy storage device, a rectifying module and a PCC (point of common connection) switch. The control platform includes a CPU, a storage module, a ZigBee wireless networking device (full-function ZigBee (FFD) main coordinator, a local ZigBee universal remote controller, and a reduced-function (RFD) ZigBee terminal node) and a peripheral interface. The control platform of the intelligent household microgrid system also includes a cloud computation background service system in the broad sense. The intelligent household microgrid combines intelligent grid, microgrid and internet of things technologies and one of great characteristics of the intelligent household microgrid is that a ZigBee wireless technology is introduced to the household microgrid so that the system is capable of networking flexibly. The intelligent household microgrid system is combined with a peak-valley electrovalency system to realize functions such as reliable power supplying through combination of self generation and grid power, intelligent scheduling of distributed photovoltaic power generation, intelligent charging and discharging of the storage device under different states, power bidirectional flowing between the system and the grid, real-time visualization of electricity quantity information and automatic switching of grid connection and grid isolation and the like.

The invention discloses a dynamic voltage restorer (DVR) for realizing smooth switching of different operation modes of a microgrid. The DVR uses a hybrid cascade H-bridge multi-level inverter topological structure as a main-body frame. A DC energy storage unit adopts a built-in wind turbine generator-storage battery of the microgrid and is serially connected between a power distribution network and a sensitive load in the microgrid through a filtering unit. The DVR is capable of working at three kinds of operation modes with the microgrid: a grid connection operation method, a grid-connection-to-island switching operation method and an island method. When it is detected that a microgrid system is to switch between two kinds of operation modes, the DVR rapidly moves and injects a compensation voltage to the system so that the microgrid is capable of smoothly transiting from one operation mode to the other operation mode. The DVR ensures the power supplying reliability of the sensitive load in the microgrid; and a transient electric energy quality problem which happens in the microgrid can be solved and a standby state of an original DVR is reduced in a large degree and thus device utilization rate is improved.

The invention discloses a dynamic voltage recovery system based on double-bus cross power supply, and the problem that the temporary drop compensation is difficult when the load-side multi-sensitive loads generate voltage sag faults at the same time is solved. A full-bridge direct-current booster circuit and a cascade 27-level inverter main circuit topology structure are adopted; a direct-currentunit supplies power according to needs by adopting super-capacitor energy storage and a storage battery pack, so that the investment of a large power grid is reduced. The voltage recovery system judges the voltage sag and voltage interruption by detecting the magnitude of the voltage sag, and which system is determined to be merged into the power grid for voltage compensation. On the basis of thedouble-bus cross power supply mode during voltage interruption compensation, the island mode and grid-connected operation modes of the compensation device are controlled to be switched, and due to thefact that the micro-grid works in three operation modes of the island mode, the operation mode of switching from the island mode to the grid-connected mode, and the grid-connected operation mode, thecross power supply of two sections of buses is realized, and the reliability of the power supply of the sensitive loads in the microgrid is ensured. According to the dynamic voltage recovery system,the voltage sag is effectively compensated, and the electric energy quality is improved.

The invention discloses a complex line full parallel AT traction power supply system and method based on comprehensive energy. The system comprises a complex line full parallel AT traction power supply system and a comprehensive energy system; a photovoltaic array, a wind generating set and a fuel cell are connected in parallel to a direct current bus, electric-hydrogen storage is added to supplement power vacancy and peak load shaving, comprehensive energy is accessed into a traction power supply system through a reasonable mode, the power and the state of each microsource are detected in real time, the energy optimization management by taking the lowest total generation cost as a target is achieved based on a particle swarm optimization. The complex line full parallel AT traction powersupply system and method based on comprehensive energy can ensure the safety and stability of the system and the high reliability of power supply; the traction energy consumption structure is optimized, and the new energy consumption level is improved; and the method meets the development direction of national energy conservation and emission reduction, and reduces the power supply requirement ofthe electrified railway on the power system to a certain extent.

The invention provides an alternating-current/direct-current hybrid micro-grid layered control method based on electricity price. The control for an alternating-current/direct-current hybrid micro-grid is divided into three layers such as a converter control layer, a bus voltage control layer and a power scheduling layer. On the bottom converter control layer, all kinds of converters are divided into energy terminals and relax terminals according to control objectives thereof; on the middle bus voltage control layer, any unit in the alternating-current/direct-current hybrid micro-grid can smoothly adjust the output power of an interface converter thereof according to a direct-current bus voltage signal under a same control structure, so that dispersion autonomous operation of the alternating-current/direct-current hybrid micro-grid is realized; on the upper power scheduling layer, a grid-connected converter decides a specific operating state according to time-of-use electricity price information on an alternating-current grid side, and then the output power of an energy storage unit is changed so as to make full use of remaining capacity thereof and improve the economy and schedulability of system operation.

The invention relates to the electrification maintenance field of a 66kV disconnector, in particular to a method for electrically disconnecting or connecting a disconnector with a drainage wire between buses. The method is characterized in that an equipotential electrician is lifted to a flexible busbar along an insulated hanging ladder, potentials are transmitted in the equipotential method, and people on the floor can realize disconnection and connection of the drainage wire by virtue of arc extinction pulleys and haulage ropes of the drainage wire. The method specifically comprises an electrically disconnection step and an electrically connection step. Compared with the prior art, the method provided by the invention has the beneficial effects that the equipotential electrician adopts the equipotential operating method, and the disconnection and the connection of the drainage wire with electricity can be realized on an aerial flexible bus bar, so that defects or hidden dangers can be eliminated, operating times of power outage and switching of operators can be reduced, reliability of power distribution of a power grid can be ensured, and a safe operation of electrical equipment can be guaranteed.

A power supply unit for an electric vehicle includes a tray and at least one battery module fixed on the tray via a strip. Each battery module includes a housing having a bottom plate mounted onto the tray, first to fourth side plates disposed on the bottom plate, a battery pack disposed in the housing and having a plurality of cells arranged along a thickness direction, and first flexible members disposed between the first side plate and the battery pack, and between the third side plate and battery pack respectively, for fastening the battery pack.

The invention discloses a DG (Distribution Generation) optimized configuration method taking into account operation risk cost of a power distribution network. The method includes steps of S1, constructing a power distribution network operation risk cost model in a DG grid connected mode; S2, constructing an operation risk cost model in a DG off-grid operation mode; S3, constructing target functions and constraint conditions of power distribution network operation risk cost according to the S1 and the S2; S4, solving S3 by adopting an improved particle swarm optimization and obtaining particles, which correspond to a configuration scheme, with the optimal adaptive value change rate. According to the invention, the DG optimized configuration model taking into account the operation risk costof the power distribution network is established; and risk costs in DC grid-connected operation and off-grid operation are taken as the target functions and DG access capacity, active power balance, no threshold crossing of node voltage, no overload of lines and no threshold crossing of reverse load flows and the like are taken as the constraint conditions in the DG multi-target optimized configuration model, and a Pareto multi-attribute decision method is adopted for processing the constructed multi-target model, so that DG optimized configuration is achieved.

The invention discloses a DC traction power supply device comprising a voltage reduction module, an AC/DC conversion module, a voltage distribution module and a DC/DC voltage conversion module which are connected in sequence, wherein the voltage reduction module is connected into a three-phase power supply through a high-voltage circuit breaker for three-phase voltage reduction; the AC/DC conversion module converts AC into DC and carries out power transmission; the voltage distribution module comprises a plurality of voltage distribution units connected in series and carries out series voltage distribution on the DC; the DC/DC voltage conversion module comprises a plurality of DC/DC voltage conversion units connected in parallel; each DC/DC voltage conversion unit is connected to one voltage distribution unit in parallel and carries out DC voltage conversion on distributed voltage output by the voltage distribution unit, and the converted voltage is output to a DC traction power supply system in parallel. The DC traction power supply device is wide in application range and small in work amount, saves cost, achieves DC power supply of the traction system under the condition of not changing an AC traction power supply network structure, and has the advantage of solving the application problems of high input voltage and large output current.

The invention relates to an intelligent grid technology and particularly relates to a micro grid energy management method. A micro grid comprises a plurality of distributed power generation units; each distributed power generation unit is provided with an intelligent agent; and communicated communication networks are designed among the distributed power generation unit and among the intelligent agents. The method comprises the following steps of: establishing an optimal mathematical model for micro grid distributed energy management; measuring and obtaining local information at grid connectionpoints where the distributed power generation units access to the micro grid, and carrying out initialization processing; implementing information exchange of the intelligent agent of each distributed power generation unit by the communication networks, calculating to obtain a reference value of active power outputs of the distributed power generation units, and according to the reference value,regulating the active power output of each distributed power generation unit; and determining an end condition. According to the method, various constraint conditions in the micro grid are comprehensively considered, a node does not need to be commanded to provide global load active demand information, fully distributed micro grid energy management can be implemented, and a calculation result is high in reliability and high in accuracy.

The invention discloses a real-time checking device and a real-time checking method for an analog quantity sampling loop of an intelligent transformer substation protecting device. The real-time checking device comprises an analyzing module, a configuring module, a sampling module, a judging module and an output module. The configuring module is connected with the analyzing module and the judging module. The judging module is connected with the sampling module and the output module. The analyzing module is used for analyzing an SCD file of the intelligent transformer substation and extracting an IED equipment list in the SCD file. The configuring module configures an interval to which each set of IED equipment is affiliated according to the IED equipment list and classifying the IED equipment according to the interval. The sampling module acquires analog quantity measurement data of each set of IED equipment from a station control layer. The judging module is used for performing redundant checking on the analog amount loop of each set of IED equipment in the interval. The output module performs outputting and displaying of a judgment result of the judgment module. The real-time checking device and the real-time checking method have advantages of improving checking speed on the condition of analog quantity loop fault of the protecting device, improving reliability of the protecting device and ensuring integral power supplying reliability of the power grid.