391results about How to "Reduce line loss" patented technology

The invention discloses an abnormal electricity utilization judgment method based on abnormal analysis of electric quantity, voltage and current. The abnormal analysis of the electric quantity comprises a fluctuation electric quantity analysis process and a zero electric quantity analysis process, wherein the abnormal analysis of voltage comprises voltage phase-failure abnormal analysis, voltage off-normal abnormal analysis and voltage unbalanced abnormal analysis; the abnormal analysis of current comprises a current loss abnormal analysis and current unbalanced abnormal analysis. By analyzing and comparing abnormal data of electric quantity, voltage and current of the users, real abnormal users or electricity stealing users can be determined. The abnormal electricity utilization judgment method based on the abnormal analysis of the electric quantity, the voltage and the current, disclosed by the invention, has the advantages that electricity information of power users can be timely grasped, the electricity stealing behavior is prevented and monitored, and the reliability of power supply is improved.

The invention relates to a method and device for performing on-load scheduling on a single-phase load in the intelligent power grid field. A master controller is mounted at an input end of a three-phase wire, a secondary controller is mounted at each single-phase branch of the wire, and the master controller exchanges information with the secondary controllers through communication interfaces. When the wire power unbalanced degree is over limit, the master controller optimizes and formulates a control scheme to operate the secondary controllers to convert the single-phase load between the phases; in the conversion process, the load is free from instant power off, and the power grid is free from impact and interference; and therefore, the distribution circuit dynamically runs in a load balance state, the unbalanced consumption problem of the circuit is completely solved.

A distribution network automation system comprises a power distribution main station, power distribution substations and power distribution terminals. The power distribution main station is responsible for monitoring and managing global information and used for monitoring and acquiring data of a whole distribution network to complete fault handling within the whole network; the power distribution substations are used for managing distribution station terminal monitoring equipment such as switchgear cubicles for loop networks, switching stations for distribution networks and the like, acquiring, gathering and uploading signals of the power distribution terminals to the power distribution main station, and transmitting orders of the power distribution main station to the power distribution terminals; the power distribution terminals mainly used for acquiring data of primary equipment, controlling switchgears, detecting and recognizing faults and sending fault information to the power distribution substations and the power distribution main station. The distribution network automation system has the advantages that power supply reliability can be greatly improved, fault time can be greatly shortened, voltage quality can be greatly improved to provide optimal voltage for users, and labor intensity can be relieved for operators; management level of the whole power distribution system can be improved, working efficiency is improved, and user service level is improved.

The invention discloses a low-voltage power grid three-phase imbalance adjustment method based on a phase-change switch. A difference between average current and the inter-phase maximum current is calculated, an average current fixed value and an inter-phase maximum current fixed value for starting imbalance adjustment is calculated according to transformer capacity and a load rate, three-phase transfer load is calculated, a load transfer direction is determined, the phase actually needs to transfer load out if the load which needs to be transferred is positive, the phase actually needs to receive load if the load which needs to be transferred is negative or zero, a phase-change switch which needs load transfer and a transferred target phase are determined according to the phase and the actual load of each phase-change switch, a phase-change switch action queue is generated, the phase-change switches are sequentially controlled to perform load transfer until all phase-change switches complete load transfer, and the system thus achieves the best balance state in the current condition. The method is used for low-voltage power grid three-phase imbalance treatment, the three-phase imbalance degree is reduced, voltage drop is reduced, power supply voltage treatment is improved, and line loss is reduced.

The invention discloses a distributed type power supply zone branch circuit three-phase load current balance monitoring method and device and belongs to the field of power supply and distribution devices. At least one three-phase load current balance main controller is arranged, load current signals of each phase circuit in each branch loop are collected, according to the obtained load current signals of each phase circuit, the three-phase current unbalance rate or the mean value of the three-phase current unbalance rate of each branch loop is computed, and the unbalance situation of three-phase load current of each branch loop is judged. The magnitude of load current in each unit meter box of each branch loop is collected, and the phase of unit meter box load which needs to be adjusted is determined. According to the three-phase load current unbalance situation of a certain branch, a control instruction is issued to an automatic phase-changing switch in a unit meter box corresponding to the branch loop, converting of load phases is carried out, adjusting of three-phase load current balance of each branch loop on the low-voltage side of a distribution transformer is achieved, and the real balance of distribution transformer low-voltage side main loop three-phase load current is guaranteed.

The disclosed real-time method to prevent electric larceny comprises: monitoring the transformer substation pass, 10KV distribution lines, special user and public power parameter by a high-voltage electric energy collection terminal; monitoring original parameters by a low-voltage electric energy collection terminal; using a wireless digital communication network to send data to the monitor center to store in database for classification and analysis, then auto drawing load curve and charge curve for different monitor point. This invention has well monitor effect and can alarm by SMS.

The invention discloses an automatic intelligent power distribution system and a power distribution method. The power distribution system comprises a power distribution executing unit, and the power distribution executing unit receives a power distribution command from a power distribution monitoring terminal and gates a corresponding phase line on a three-phase power transmission line to a single-phase power supply line on an output side of the power distribution executing unit to achieve intelligent power distribution. According to the automatic intelligent power distribution system, low-voltage three-phase disequilibrium distribution on an input side of a single-phase user is achieved through the power distribution executing unit on an input side of an electricity meter of the single-phase user, the power distribution monitoring terminal receives the electrical load information of each single-phase user in a wireless or power line carrier communication mode, and a basis is provided for the equilibrium distribution of single-phase user quantity on each phase line of the three-phase power transmission line on the whole; the power distribution monitoring terminal sends the power distribution command to the power distribution executing unit and the power distribution executing unit enables each single-phase user to be connected to a corresponding power supply phase line in a grouping mode, and therefore equilibrium power distribution is achieved for single-phase users on a low-voltage side.

The invention relates to a dynamic loss reduction method for a distribution network and a synthesized loss reduction system of a distribution network. A principle that an electric field and a magnetic field are mutually symbiotic and affected is applied for dynamically realizing electromagnetic balance; the treatment of'peak load shifting'is carried out on the current difference value between three-phase unbalanced currents caused by the dynamic unbalance of the power used by a three-phase load at the secondary side of a distribution transformer so as to lead the current difference value to approach balance, reduce a zero sequence current and the unbalance degree of the three phases, and restrain a harmonic, thereby realizing the self loss (loss on transmission) of the distribution transformer and the line loss (the copper loss of the line) at the first side and the secondary side of the distribution transformer; the synthesized loss reduction system of the distribution network realizes the synthesized loss reduction management of the distribution network, the loss on transmission of the distribution transformer as well as the automatic measuring and accounting on the data of the copper loss of the line at the first side and the secondary side thereof; the system also realizes the remote automatic collection on the power data of the distribution transformer in the same time as well as the accounting of the line loss of a distribution line, calculates and accounts the line loss of the distribution network, calculates and analyzes the loss reduction as well as analyzes the benefits of energy saving and emission reduction.

The invention discloses a direct-current de-icing method of an overhead ground wire and a composite optical fibre ground wire. A direct-current de-icing device used in the direct-current de-icing method comprises a converter, a direct-current side switch and a control protection system. A whole wire is electrically communicated with two insulated overhead ground wires or one insulated overhead ground wire and connected with an insulated composite optical fibre ground wire in parallel; a one-phase conductor is served as a return wire; after the head ends of the two insulated ground wires are short-circuited, the two insulated ground wires are connected to the cathode of the converter in the direct-current de-icing device through the direct-current side switch; the tail ends of the two insulated ground wires are short-circuited with the tail end of any one-phase conductor in a three-phase alternating-current circuit to be de-iced; the any one-phase conductor is connected with the anode of the converter in the direct-current de-icing device through the direct-current side switch; and the control protection system is connected with the converter. According to the de-icing method usingthe direct-current de-icing device, the voltage to ground of the insulated ground wire in the process of de-icing can be obviously reduced; and the operation voltage requirements of a ground wire insulator and a parallel clearance thereof are reduced; and therefore, wire losses resulted from the overhead ground wire and the composite optical fibre ground wire are greatly reduced.

The invention discloses an abnormal electricity consumption judging method based on analysis of abnormal electric quantity. The method comprises a fluctuating electric quantity analysis process and a zero electric quantity analysis process; the fluctuating electric quantity analysis process comprises the steps: analyzing and giving a user list with possible abnormal electric quantities; with respect to an user with abnormal electric quantity, appointing the electricity consumption in a certain period and comparing it with the specific historical electricity consumption of the user, calculating a fluctuation proportion and considering the user to be the abnormal electricity consumption user when the fluctuation proportion exceeds the expected fluctuation percentage value. The zero electric quantity analysis process comprises the steps: giving a list of electricity users, the daily electricity consumptions of which are zero and are abnormal electricity consumptions; analyzing and checking the abnormal users by work staff and confirming what users with abnormal electric quantities are true abnormal electricity consumption users. The abnormal electricity consumption judging method based on analysis of abnormal electric quantity has the advantages of immediately knowing power users' electricity consumption information, preventing and monitoring electricity stealing behaviors and improving power supplying reliability and the like.

The invention relates to a transformer district line loss rate pre-estimation method, and the method comprises following steps: 1, original sample data collecting, analyzing and processing: all transformer district data of a power supply company is collected and pre-processed; 2, a K-means clustering method is adopted to classify all transformer district data of the power supply company according to transformer district features, and the transformer districts in the administrative region of the power supply company is divided into K' class groups with different features; 3, basic data and a predicted value of each class of typical transformer district are associated, and a mathematical prediction model is established through a way of linear regression; 4, to-be-predicted data is inputted to the model, and an output reasonable required prediction feature data predicted value is obtained, so that a reasonable required prediction feature data predicted value of each class of transformer district is obtained. According to the invention, the method provides effective auxiliary for power supply work through the output reasonable required prediction feature data predicted value.

The invention relates to a load distribution based method for calculating recently planned annual line loss of a medium-voltage distribution network. The method comprises the following steps of: (1) calculating a load distribution coefficient of a typical load distribution line; (2) calculating a load distribution coefficient of an actual line; (3) virtualizing a return line, wherein parameters related to line loss calculation are all average parameters, and the loss of the return line is used as the average loss of the medium-voltage line of the planning area; (4) calculating the loss of a trunk line of the virtual line; (5) calculating the loss of a branch line of the virtual line; and (6) calculating the loss of the medium-voltage line in the planning area. The method has reasonable design, solves the problem that the failure of acquisition of the load data of a recently planned annual distribution network causes difficulty in line loss calculation, realizes the quick estimation of the line loss of the whole planning area and has the characteristics of simple operation, easier obtaining of collected data and short calculation time.

The invention provides an automatic balance device of a distribution network with three-phase load balance, which relates to a device able to automatically regulate the distribution network with three-phase load balance, aiming to solving problems that in the prior art, an adjustment method of the distribution network three-phases load balance is only able to cause the distribution network nearly to the three-phase balance with the disadvantages of waste of time and vigor, requirement of a shutdown and delay manufacture. In the invention, a voltage detection module, an electric current detection module, a voltage across-zero-aberration detection module and a solider relay and power-supply module are connected with the three-phase distribution network; the voltage detection module and the electric current detection module are connected with an electric energy computation module; the electric energy computation module is connected with an interface electric level switching module; the interface electric level switching module is connected with a master controller; the voltage across-zero-aberration detection module is connected with a slave controller; the control input terminal of the slave controller is connected with a control output terminal of the master controller; the solider relay is connected with a first rectifier; the solider relay is connected with the slave controller; the first rectifier is connected with a first inverter; the first inverter is connected with a parallel-in module, and the parallel-in module is connected with the three-phase distribution network.

The invention discloses a distribution network reconfiguration method, which comprises the following steps: building a distribution network load optimization model; and optimizing the distribution network load optimization model on the basis of a genetic algorithm, and obtaining a distribution network reconfiguration scheme. The reconfiguration is carried out on a distribution network on the basis of a genetic method; and load reconfiguration is carried out by changing the state of a switch, so that line loss of the distribution network is reduced; the benefits are improved; and the power supply reliability and safety are improved.

The invention provides a greedy algorithm-based scheduling policy for the three-phase load balance of a real-time-allocating distribution network and relates to a scheduling policy for the three-phase load balance of the real-time-allocating distribution network. The scheduling policy comprises the steps of (1) establishing an array Z with the length thereof to be equal to the number of slave switching devices in the distribution network; (2) conducting the real-time online detection on the total currents of three phases Ia_ph, Ib_ph and Ic_ph, and the currents of all users loads of the slave switching devices; (3) determining the value of epsilon; (4) sorting user loads respectively accessed to three phases of A, B and C in the monotonically increasing manner, and respectively storing in linked lists a, b and c; and so on. Compared with the conventional algorithm, a corresponding scheduling scheme can be found out more quickly based on the greedy algorithm. Meanwhile, a plurality of slaves can be simultaneously controlled in the online manner, so that the three-phase unbalance degree of the distribution network is quickly decreased within a short period of time. Therefore, the time-varying characteristics of the electrical loads of the distribution network can be treated.

The invention discloses a power distribution area energy conservation and loss reduction method based on load prediction and phase sequence optimization. The method comprises the steps of collecting data of a power distribution area; filling the missing data value by using an EM algorithm; calculating line power flow by using real data of the day of the phase modulation day, using the three-phasecurrent at the outlet of the transformer area as a daily load curve of each phase and using a forward-backward sweep method to obtain theoretical line loss of the power distribution transformer area;based on historical data, predicting outlet three-phase current of a phase modulation day and daily electric quantity of each user in the power distribution area by utilizing an Elman neural network;establishing an optimal commutation mathematical model taking the minimum line loss of the power distribution area and the minimum commutation frequency in the commutation process as targets, and solving the optimal commutation mathematical model by using a genetic algorithm to obtain each user phase sequence after phase modulation; and comparing the line loss and the three-phase imbalance degreechange of the user before and after the phase sequence is adjusted. The method can effectively predict the operation data of the power distribution area, and is used for the phase sequence adjustmentof the power distribution area, thereby enabling the area to achieve the energy saving and loss reduction.

The invention provides a realization method for functions of an adaptive load type distribution transformer. The realization method comprises the following steps of setting adaptive load type distribution transformer motion constant values which include a three-phase load unbalance adjusting constant value, a phase-splitting reactive compensation constant value, a load capacitance-modulating current constant value and a load voltage-modulating voltage constant value, and according to the set adaptive load type distribution transformer motion constant values, performing three-phase load balance control, phase-splitting reactive compensation control, rated capacity operation model adjusting control and voltage tap shift adjusting control. The realization method fulfills an aim of adaptive loads by scientifically setting the load capacitance-modulating motion constant value and combining the three-phase load unbalance adjustment and phase-splitting reactive compensation strategy, helps to effectively reduce operation loss of the distribution transformer and low-voltage network wire loss, improve the economic operation level of the power distribution area and guarantee power supply quality to users.

The invention discloses a loss reduction and energy conservation method and system. The method includes the following steps that: a center server (21) builds a power transmission line diagram, calculates the line loss of each section in a piecewise manner and performs weighing on the line loss to obtain theoretical line loss, and calculates actual line loss and transmits control information to a detection device (22); and the device (22) receives the control information and intelligently controls the compensation capacitance in an intelligent capacitor bank according to reactive power compensation in the control information. With the loss reduction and energy conservation method and system provided by the embodiment of the invention adopted, the calculation result of the theoretical line loss is more accurate, and line loss caused by three-phase imbalance can be effectively reduced, and loss reduction and energy saving can be realized.

The invention discloses an environmental-friendly power cable which comprises a core wire, an aluminum tape layer lapping outside the core wire and steel-tape armoring arranged outside the aluminum tape layer, wherein the gap between the core wire and the aluminum tape layer is provided with silicon carbide mineral composite fillers, a polyethylene inner sheath is arranged between the aluminum tape layer and the steel-tape armoring, and a polyethylene outer sheath is arranged outside the steel-tape armoring. The invention has the advantages of good heat radiation property, long service life, strong flame retarding property, electricity saving, no toxicity and environmental protection.

The invention relates to a low-sag annealed aluminum wire, in particular to a special cable for overhead power transmission line, which is applicable to the construction and reforming of overhead transmission lines. The invention comprises two parts, namely, a core and a plurality of conductors; wherein, the conductors are arranged outside the load-bearing core, and the conductors adopt full annealed aluminum wire with a conductivity of 63% IACS; besides LB10 super high strength aluminum-clad wire or EST super high strength galvanized steel wire, the load-bearing core also adopts G3A super high strength galvanized steel wire or carbon fiber composite materials. The cable is in the composite structure with circular wire or shaped conductor, or with single circular wire and shaped conductor.

The invention provides a medium-voltage frequency converter capable of realizing AC-AC (alternating-current) direct transformation, belonging to the technical field of frequency converters and comprising a reduction transformer and three converter arrays, wherein three three-phase secondary windings of the reduction transformer are respectively connected with input ends of the three converter arrays. The medium-voltage frequency converter is novel in conception, strong in generality and simple in overall structure, and can improve power factors of network sides.

The invention provides a three-phase load transfer device, comprising an input module, an input measurement module, a phase sequence adjustment module, a phase sequence display module and an output module, wherein the input module provides the input of the three-phase alternating current, and the input phase sequence of the three-phase alternating current is ABC; by measuring the levels of the current and the voltage of the three-phase alternating current which is input into the input module, the input measurement module judges whether the three-phase load is imbalanced or not; in order to provide three output phase sequences, namely ABC, BCA and CAB, the phase sequence adjustment module adopts three independent contactors for the three-phase current of which the input phase sequence is ABC; when the input measurement module detects the imbalance of the three-phase load by measurement, the operation of switching the output phase sequences is carried out, otherwise, outputting is carried out according to the original phase sequences; the phase sequence display module provides three indicator lights, and each indicator light corresponds to one of the three output phase sequences, namely the ABC, the BCA and the CAB, so as to display the current output phase sequence; and the output module outputs the three-phase alternating current into the load after the phase sequence adjustment module adjusts the phase sequences.

The invention provides an apparatus and method for automatically improving terminal voltages of a low-voltage three-phase line. When first terminal voltages are not within a normal scope, a reactive compensation unit carries out compensation and acquires second terminal voltages and currents after the compensation, and if the second terminal voltages are still not within the normal scope and are greater than a voltage upper threshold and when the current imbalance degree is not within a normal scope, an implementation commutation switch implements commutation; when the second terminal voltages are smaller than a voltage lower threshold yet the current imbalance degree is within the normal scope, power transfer compensation is carried out; if the current imbalance degree is not within the normal scope, after the power transfer compensation is performed, third terminal voltages and currents are acquired; if the imbalance degree of the third terminal voltages is within the normal scope, commutation voltage regulation is stopped; and otherwise, the commutation switch implements the commutation.

This invention relates to a power dispatch method especially to a reactive tide dispatch method to distribution networks, which sets a reactive compensation device with the volume adjusted in many stages at the trunk load center of the distribution networks, sets an electric data collector with radio data communication function at each node [1, 2,apostrophe, n-1, n]to collect voltage U1, active load Pi, reactive load Qi, the active power Pi, i+1 and reactive power Qi, i+1 flowing to the next node, computes the total active power loss value, tries to move the reactive dividing line point to its adjacent node [j+1 ] from the initial reactive dividing line point, computes the total active power loss value at the new reactive dividing line point to regulate the output of the reactive compensation device.

The invention provides a power-voltage coordination control method and device for a DC power distribution network, and the method comprises the steps: building a long-time scale system optimization control model according to the network topology, power and load conditions of the DC power distribution network; solving the long-time scale system optimization control model, and calculating the flow distribution of the DC power distribution network and the power reference value and voltage reference value of a current converter station; determining a sagging control curve according to the power reference value and voltage reference value of the current converter station; and achieving the no-difference adjustment of voltage according to the sagging control curve during load disturbance. The device comprises a modeling unit, a solving unit, a sagging curve control unit, and an adjustment unit. According to the technical scheme of the invention, the method can improve the operation reliability of a power grid, and guarantees the electric energy of the DC power distribution cabinet.

The invention discloses a low-voltage, large-load and customized power adjustment and control method. The method includes the following steps that: a rated capacity value is preset in an intelligent electricity utilization device according to electricity utilization load capacity applied by a user; the intelligent electricity utilization device monitors actual electricity utilization load of the user in real time and judges whether the actual electricity utilization load satisfies conditions of alarm protection action startup, if the actual electricity utilization load satisfies the conditions of alarm protection action startup, an alarm protection action is started; the intelligent electricity utilization device judges whether the cumulative number of times of overload alarm protection in a single period achieves a preset numerical value of number of times of locking, if the cumulative number of times of overload alarm protection in a single period achieves the preset numerical value of number of times of locking, the intelligent electricity utilization device locks a switch-off cut-off circuit; and the rated capacity value preset in the intelligent electricity utilization device is increased according to the application of the user for increasing electricity utilization load capacity, and the switch-off cut-off circuit is unlocked, and power transmission work is recovered. The invention also discloses an intelligent electricity utilization device. With the low-voltage large-load customized power adjustment and control method and the intelligent electricity utilization device of the invention adopted, the user can be urged to quickly adjust the electricity utilization load to a safe operation state, timely handle capacity increasing application and report actual electricity utilization load capacity.

The invention provides an antenna system and a mobile terminal. The mobile terminal comprises a metal frame. The metal frame comprises two corners which are arranged diagonally, a long frame and a short frame, wherein the long frame and the short frame are connected to the two ends of the corners. The antenna system comprises four SIW horn antenna arrays formed on the metal frame. The circumference side of each corner is provided with two SIW horn antenna arrays which are vertical to each other. One SIW horn antenna array is arranged at one end of the long frame connected to the corner, wherein the end is close to the corner. Another SIW horn antenna array is arranged at one end of the short frame connected to the corner, wherein the end is close to the corner. The SIW horn antenna arrayscomprise a plurality of SIW horns. The positions of the metal frame, which correspond to the SIW horns, are provided with a plurality of through holes which are arranged at intervals. The total covering efficiency of the antenna system and the mobile terminal is good.

The invention relates to a transformer low-voltage connection passive compensation of electrolysis system and relative active filter device, wherein the secondary side of transformer is connected to the rectifying device and the electrolytic tank; the secondary side of transformer is parallel connected to the rectifying device and connected to at least one group of capacitor compensators and one group of active filters; one end of first group of capacitors is connected to the main circuit of secondary side of transformer; one end of second capacitors is connected to the main circuit of end of secondary side of transformer; another end of two groups of capacitors are parallel or serially connected; one end of first group of active filters is connected to the main circuit of secondary side of transformer; one end of second group is connected to the main circuit of the end of secondary side; another end of two groups of active filters is connected to the capacitor or the inductor. The invention passively treats the harmonic wave from source, with dynamic and on-site compensation, to save energy and increase yield.

The invention provides an AC / DC hybrid active power distribution network operation control method. Three AC / DC hybrid active power distribution network operation control modes: a normal state, an early warning state and an emergency state are included. When the AC / DC active power distribution network is in the normal state, an optimal control strategy with improvement of a distributed power consumption level, realization of load balance and reduction of line loss as targets is built. When the AC / DC active power distribution network is in the early warning state, a DC power flow solution method is applied and an active power sensitivity concept are introduced, the minimum active power regulation amount serves as a target to eliminate hidden safety dangers such as line power flow overload, and a safety coordination control strategy is built. When the AC / DC active power distribution network is in the emergency state, in view of N-1 fault, through calculating the power which needs to be supported by a flexible DC device, a power support strategy is built. Different control strategies in three operation states are integrated, and the power supply reliability and the operation efficiency of the AC / DC hybrid active power distribution network can be improved.