310results about How to "Reduce network loss" patented technology

The invention provides an electric car intelligent charging system and method on the basis of a mobile device and belongs to the technical field of electric car charging positive intelligent control. The system comprises a power grid management center, a station level management server, the mobile device, a charging device and a power battery. The station level management server comprises a data input module, a data processing module, a data feedback module and a historical data memory module and is used for calculating, solving and achieving the real-time optimum order charging scheme, outputting specific charging orders to the charging device and the mobile device and feeding back the charging information. According to the method, the local optimum greedy algorithm is used for solving the real-time optimum order charging scheme, the user interaction character is achieved, and the order charging scheme of an electric car is obtained by carrying out data mining and predicting on the user data and the power grid data and carrying out performance analysis on the power battery. Under the circumstance of ensuring that battery loss is small, the electric car intelligent charging system and the method greatly meet the individual requirements of the users and achieve effective optimization of a power grid.

The present invention discloses a decentralized cooperative economic dispatching method comprising a multi-microgrid active distribution system. The method comprises the following steps: (1) establishing a distributed power supply optimization operation model, solving an optimal scheduling model, calculating a microgrid node electricity price, considering a micro gas turbine in a microgrid, a fuel cell, output force characteristics and energy consumption characteristics of an energy storage device and wind power and photovoltaic random output force characteristics, and employing a prime-dual interior point method to calculate each node electricity price of the microgrid; (2) designing a multi-microgrid decentralized cooperative optimal scheduling frame to determine the size of each distributed power supply output force; and (3) researching the active distribution system optimal scheduling model and the solution method thereof considering the influence of multi-microgrid access. The decentralized cooperative economic dispatching method comprising the multi-microgrid active distribution system improve the electric energy quality and peak load shaving capability of the distribution system through depending on the support of the microgrid layer and network reconstruction while economic operation so as to provide valuable reference for allowing the microgrid system to access the distribution system optimal scheduling.

The invention discloses a power distribution network operation aid decision analysis system and an application method thereof. The system comprises a data layer used for classifying and storing acquired external data; the platform layer is used for classifying the data stored in the data layer and building an operation module according to the type; the application layer is used for classifying thestored data according to the operation modules and the data layer built by the platform layer; risk analysis is carried out on the power distribution network and an optimization scheme is provided, the display module is also used for displaying result information of each operation module; the difference characteristic of the urban power distribution network is fully considered from the overall architecture design to the specific service function design, the power distribution network is directly operated, maintained and overhauled, corresponding measures are put forward in a targeted mode forintelligent auxiliary decision analysis of the power distribution network, and the probability of power distribution network faults and risks is reduced.

The invention discloses a method and system for multi-target reactive power optimization of electric power systems. The method comprises the following steps of: establishing a multi-target reactive power optimization model; generating positions of N initial bird nests by utilizing Kent chaotic mapping, taking the positions of the N bird nests as initial populations, calculating a fitness value of each bird nest, establishing an external file set according to a Pareto dominance relation, updating the positions of the bird nests according to self-adaptive weights, updating the external file set according to the dominance relation and calculating a congestion distance to control the capacity of the file set; carrying out a differential evolution operation on each bird nest and updating the external file set; and when an iteration termination condition is satisfied, outputting an optimum Pareto optimal solution set. According to the method and system, a plurality of target functions are considered, so that the disadvantages that the traditional method is used for converting a plurality of targets into a single target and is difficult to determine the weight coefficients are optimally overcome; an improved cuckoo search algorithm is high in convergence rate, high in precision and good in individual diversity; and the obtained optimal solution set has favorable diversity and uniform distributivity, and can be well adapted to solving the multi-target reactive power optimization problems of the electric power systems.

The invention discloses a power distribution network reactive power optimization system and method based on multi-data analysis. The system comprises: a distribution network data acquisition device for acquiring 10kV line outlet node real-time data and transmitting the same to a host computer control system; a dynamic reactive power compensation device for uploading distribution network operating data and reactive power compensation device running status data to the host computer control system by using GPRS. The method, through the EMS and distribution network automation system, get access to the data of each node of a 10kV line, carries on the load flow calculation, obtains the distribution of the voltage, active power and reactive power of each node of the line, and makes the line run in an optimal state through reactive power strategy control, develop reactive power optimization strategy through a genetic algorithm to determine the compensation point, compensation capacity and the like, controls the reactive power compensation equipment in the distribution network to achieve full distribution network reactive power optimization operation control.

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.

The present invention discloses a method of utilizing distributed energy and temporary additional electricity price to optimize control cooperatively. The method comprises the steps of S1 determining power supply areas and a grid structure; S2 predicting the morrow RDG output and the user original load; S3 calculating the user load after the time-of-use electricity price; S4 carrying out the day-ahead optimization scheduling on the power supply areas, and starting a standby set in necessity; S5 gathering the output of the standby set; S6 carrying out the intra-day rolling calculation, namely controlling the RDG output and the user load according to the temporary additional electricity price; S7 gathering the RDG output reduction quantity and the user load reduction quantity. According to the present invention, a more flexible and changeable and more reasonable scheduling mode is provided for an active power distribution network, and fully embodies the distributed energy real-time scheduling control capability, the load flow bidirectional management capability and the distributed energy admission capability required by the active power distribution network, thereby improving the overall operation stability and robustness of the power distribution network.

The invention discloses an electric vehicle charging real-time optimization dispatching method. The technical scheme adopted by the invention is as follows: Net-Electrified Transportation CooperativeSystem Architecture Based on Vehicle Interaction; A micro traffic assignment model based on travel chain tracking is established to track and simulate the real-time information of driving behavior, location distribution, state of charge and charging demand of electric vehicle users. Charging station selection and navigation strategy; A two-layer real-time optimal dispatching model is constructed to determine the specific charging scheme of electric vehicles in each charging station, which takes into account the safety of distribution system and the waiting time of users. YALMIP/CPLEX efficientcommercial solver is used to solve the upper and lower level problems iteratively. The invention can not only alleviate the traffic jam near the charging station; But also can make the load distribute evenly, reduce the network loss and ensure the safe and economical operation of the power network; Also can meet the EV charging demand, improve customer satisfaction, and ultimately achieve the overall optimization of electrified transportation system operation, taking into account the interests of many aspects.

The invention discloses an AC/DC power distribution network scheduling method considering wind power uncertainty, being characterized in that factors such as a flexible adjustment range, an adjustmentrate and adjustment time are considered; quantitative evaluation is carried out on source network load flexibility resources of the AC/DC power distribution network; an AC/DC power distribution network operation flexibility evaluation index and a calculation method are defined; based on non-parametric kernel density estimation and a confidence interval method, constraint conversion of a power distribution network flexibility demand considering wind power uncertainty is realized; and an implementation scheme of a layered and partitioned scheduling strategy in the AC/DC power distribution network is determined, and a multi-target day-ahead flexible economic scheduling model of the AC/DC power distribution network is established by taking the operation economy and the electric energy qualityof the power distribution network as target functions and taking controllable operation parameters in the converter station and the AC/DC power grid as decision variables. On the premise of ensuringthat the AC/DC power distribution network deals with system uncertainty fluctuation, the system network loss is further reduced, and the node voltage level is improved, and the RES acceptance level isimproved, and the total system scheduling cost is reduced.

A load flow calculation method of a distributed power supply connection power grid comprises the steps that S1. initial data of an electric power system are read; S2. sampling frequency N and the dimensions s of input random variables are determined; S3. an s * N order sampling matrix is generated; S4. sampling frequency is initialized, namely n is equal to 1; S5. whether n is larger than the sampling frequency N is judged, and yes, the probability statistics results of the variables are directly output; otherwise, S6 is carried out; S6. a wind power and photovoltaic power generation output model is determined, and a load random model is determined; S7. a load flow calculation model is determined; S8. an optimized economic model is determined; S9. load flow calculation is carried out; S10. data such as voltage, branch power and power generation cost of a <n>th node group are determined; and S11. a next round of load flow calculation is carried out, t is equal to t + 1, and S5 is carried out. The probability distribution of the output random variables can be estimated well, the uncertainty problem in an electricity market can be well solved, debugging manpower and material resources are saved, and production cost is lowered.

The present invention relates to a power distribution network reactive power compensation planning method. Through the setting of a reactive power compensation planning target, condition constraint and selected typical region calculation and the expansion to an entire network, the optimal compensation capacity and economic efficiency of reactive power compensation planning are obtained, the network loss is effectively reduced by using the reactive power compensation planning, the reasonable configuration of a reactive power compensation capacity is realized, and the safe and economic operation of a power system is ensured.

The quality of power supply and the reactive compensation combination controller belongs to the field of the dynamic voltage compensation and reactive compensation technology of the power system. It adopts the design of the series-parallel connection, connects with the silicon controlled in series and with the inverter parallelly through the measure and control circuit centered on the DSP in normal working and increases the reliability and efficiency. When the voltage falls, the inverter will send out the corresponding sine wave to compensate the needed quantity of the voltage and thus can guarantee the failure free operation of users' equipments. When users' reactive demand is excess or negative and affects the level of the voltage, it will devote the shunt-wound general-patching capacitor in stages or get rid of it to compensate the reactive. When the interphase reactive is not balanced, solve the problem of the imbalanced interphase reactive through the casting control to the shunt-wound capacitor. It also solves the problems of fall of the alternating voltage and the reactive compensation in the power system and improves the level of the voltage.

The invention discloses an AC and DC hybrid micro-grid optimal planning method considering a line factor. The method comprises: establishing a target function of an AC and DC hybrid micro-grid considering a line factor relative to investment cost, loss load cost, and system loss, comprehensively considering system power constraint, system branch constraint, distributed energy output constraint, node voltage deviation constraint, random fault constraint of equipment and other constraints, using Monte Cario to perform fault sampling, through mixed integer linear programming, solving, to obtain ascientific and economical AC and DC hybrid micro-grid distributed power addressing capacity grading optimal configuration result. The method solves a configuration problem of effective access of a distributed power supply in expansion planning of an AC micro-grid, improves on-site elimination capability of the hybrid micro-grid, and meanwhile realizes economical efficiency and reliability of planning of the AC and DC hybrid micro-grid.

The invention relates to a power distribution network distributive power supply optimal access capacity determining method based on cone optimization. The method comprises the steps that according to a power distribution system to be expanded and planned, initial values of the line parameters, the load level, the network topology connection relationship, the distributive power supply access position, the power factor, the reference voltage and the reference power are input; a mathematical model for a distributive power supply optimization capacity problem according to each parameter; the rotary cone restriction is set according to a network structure and the scale; a cone optimization method is adopted for solving the rotary cone restriction and the mathematical model of the distributive power supply optimization capacity problem; solving results are output, and the solving results comprise distributive power supply optimal allocation conditions, network power flow results and target function values. The optimal access capacity of a distributive power supply in a power distribution network is determined by the cone optimization method. The consistency of the solution and the original problem of the cone optimization problem is ensured through the rotary cone restriction, the access number of the distributive power supplies are not limited, and the simultaneous optimization of the capacities of a plurality of distributive power supplies can be realized.

The invention relates to a power supply recovery method of a power distribution network comprising distributed power supplies after a fault. The power supply recovery method is technically characterized by comprising the following steps of (1) splitting the distributed power supply which does not have isolated island operation capability after a large-area power failure condition is caused by the fault of the power distribution network; (2) carrying out isolated island division by using a searching method on the basis of the principle that the distributed power supplies run with surrounding loads, and then enabling an isolated land, with the surrounding load, of the distributed power supply with the isolated island operation capability to run; (3) isolating a fault point and recovering power supply of the remaining sound network; and (4) enabling the distributed power supply or isolated island with a grid-connection condition to run in a grid-connection manner and enabling the isolated land without the grid-connection condition to further run. The effects of the distributed power supplies can be fully developed under the premise of recovering load power supply as much as possible; the important load power supply reliability is improved; meanwhile, the switching action frequency is reduced as few as possible in the power supply recovery process; and the network loss is reduced as much as possible after power supply recovery.

The invention discloses an energy-saving management platform based on whole network monitoring reactive compensation technology. The energy-saving management platform comprises a master control program module, a database module and an SCADA system interface module. The SCADA system interface module is used for allowing a reactive voltage optimization server to collect state parameters of the head end of a 10kV distribution network from an SCADA system of a dispatching center; and the master control program module is used for allowing a master control program to obtain such data from a memory database of the database module, then, carrying out a series of calculating and processing to generate comprehensive instructions for adjusting capacitors and taps, and sending control information to each controller to execute operation. The management platform realizes display of data information, such as node voltages, transformer current, capacitor compensation capacity, bus switch state and power factor, which are controlled by different controllers, in a display device, and realizes remote control of behaviors of each controller; and in the analysis process, the system can keep records of the whole process according to actual needs, thereby providing data basis for follow-up analysis.

The invention discloses a method for an AVC (Automatic Voltage Control) system to verify power network global optimal control parameters. the optimal control parameter group and the optimal reactive power flow distribution are verified by being based on EMS (Energy Management System) real time data and the power network state estimation, and based on a uniform typical, substituting load daily historical data, and comparing the pivot node voltage regulation speed rates, the voltage control quality rates and the power network loss values respectively. By adopting the method disclosed by the invention, the problem in the prior art that the AVC substation parameters can not be verified to be optimum in the power network is solved, thus the method provides conditions for achieving the final goal of qualified node voltage in the power network and minimized network loss; and the method also can be used for verifying the optimal reactive power flow distribution, and provides aided decision evidences for investing in the power network construction.

The invention discloses a control device and method based on a phase angle of a phase current of a direct-current brushless motor. The control device comprises a speed setting module, a central processing unit, a current amplifying circuit, an intelligent power module, Hall sensors and a power source module which provides power for the speed setting module, the central processing unit, the current amplifying circuit, the intelligent power module and the Hall sensors. The control method comprises the steps that the real-time rotation speed of the direct-current brushless motor is collected and counter emf is obtained at the same time; the real-time phase current of the direct-current brushless motor is collected, and speed PI adjustment is conducted on a speed difference between the real-time rotation speed and a set rotation speed, so that a speed adjustment signal is obtained; PWM compensation calculation is conducted on the real-time counter emf and the phase deviation of the phase current of the direct-current brushless motor, so that a PWM compensation amount is obtained; a PWM duty ratio signal is obtained through calculation conducted by the central processing unit according to the speed adjustment signal and the PWM compensation amount; the PWM duty ratio signal is output to the intelligent power module, so that control over the phase of the phase current of the direct-current brushless motor is achieved. By the adoption of the control device and method based on the phase angle of the phase current of the direct-current brushless motor, the motor efficiency is improved, and the amount of emitted-heat is reduced.

The invention relates to a peaking strategy optimization method considering the safety constraints of a wind power integration system. On the basis of analysis of the change in peaking demand of a wind power integration system, an improved optimization model based on thermal power, hydropower and pumped storage joint peaking is built by taking maximum consumption of wind power as the goal and considering factors minimizing peaking generation cost and line loss and meeting power flow safety constraints, and the solving method of the improved optimization model is studied using optimal power flow and particle swarm algorithms. Through the peaking method, an effective peaking unit output scheme can be determined under the premise of ensuring safe and economic operation of the system, the cost of power generation can be reduced effectively, the safety of the system can be ensured, and large-scale wind power can be consumed as much as possible. Finally, the peaking strategy optimization method studied is simulated and verified.

The invention relates to a reactive power planning method of wind power grid-connected system considering static transient voltage stability, load probability density and wind speed Weibull distribution is divided into different scenarios, a reactive power programming model of the wind power grid-connected system is established by using a two-layer programming method and solved by Gaussian inverselearning particle swarm optimization algorithm. The static reactive power compensation equipment capacity of the optimal static reactive power compensation node and the dynamic reactive power compensation equipment capacity of the dynamic reactive power compensation node of wind power grid-connected system are outputted. Compared with the prior art, the invention has the advantages of reducing the cost of network loss and reactive power compensation, and improving the static transient voltage stability of the system under different operation states.

The invention relates to a method for acquiring coordinated constraint upper and lower limits of provincial-regional coordinated busbar voltage, and belongs to the technical field of power system automatic voltage control. The method comprises that: based on quasi-steady-state sensitivity, a second time programming model is constructed to calculate the upper limit of the coordinated busbar voltage which can increase reactive power output of a provincial dispatching generator as possible under the conditions of meeting a generator busbar voltage constraint limit, a coordinated busbar voltage operating constraint limit, a monitoring busbar voltage constraint limit and a generator reactive power constraint limit, and the lower limit of the coordinated busbar voltage which can decrease reactive power output of the provincial dispatching generator as possible under the conditions of meeting the generator busbar voltage constraint limit, the coordinated busbar voltage operating constraint limit, the monitoring busbar voltage constraint limit and the generator reactive power constraint limit. The method can effectively reduce grid loss and improve voltage safety level of power grids.