51 results about "Loop analysis" patented technology

The invention relates to a method for analyzing turn-to-turn faults of a generator rotor based on a multiloop model, belonging to the technical problem of analysis and research of asymmetric fault problems of alternating current motor windings and relay protection of power system master devices. In the invention, based on a multiloop analysis method of an alternating current motor, a voltage and flux linkage equation is listed according to actual connection conditions of all stator and rotor loops in consideration of various space harmonics of air gap magnetic field caused by rotor faults, unbalance current inside a stator phase winding and the change of a topological structure of an excitation winding circuit; various loop parameters, particularly induction parameters related to an excitation winding generating turn-to-turn short circuit faults are accurately calculated, and a transient state calculation method and a stable state calculation method for the turn-to-turn short circuit faults of the excitation winding are provided. Experimental results prove the correctness and the accuracy of the two calculation methods and provide a quantified basis for designing turn-to-turn short circuit protection.

The invention discloses a three-phase load flow calculation method of a weak looped distribution network comprising multi-type distributed power sources. Firstly, the effective three-phase load flow calculation method of a weak looped distribution network is put forward in a distribution sequencing network based on a sequence component calculation method and in combination with characteristics of the weak looped distribution network and a loop analysis of a road. Secondly, detailed formula derivation of iterative computation of distributed generation (DG) of a PQ node type, a PQ (V) node type, an OV node type and a PI node type is conducted and the easy formula is introduced into the load flow calculation method. The three-phase load flow calculation method of the weak looped distribution network comprising the multi-type distributed power sources can effectively process multi-type DG and the weak looped distribution network and is distinct in calculation procedure, simple in programming, and easy to achieve. In addition, the three-phase load flow calculation method of the weak looped distribution network comprising the multi-type distributed power sources retains strong points of rapid calculation and stable convergence of a forward-back substitution method catering to branch circuits. Finally, effectiveness and good convergence of the three-phase load flow calculation method of the weak looped distribution network comprising the multi-type distributed power sources is tested and verified by means of a IEEE (institute of electrical and electronic engineers)-37 generatrix test calculation case, and the three-phase load flow calculation method of the weak looped distribution network comprising the multi-type distributed power sources has good ability of processing the multi-type DG and the looped network.

The invention is an optimization method of main protection configuration of internal failure of a large-scale generator stator winding, advancing a multiloop analysis method of AC machine, considers an electric machine as a circuit network with relative movement to research its movement behavior by general circuit analysis methods, and can flexibly analyze the influence of various harmonic magnetic fields, space position and from of its winding, etc, thus solving the problem of simulation and calculation of the internal failure. On the basis of complete simulation and calculation of internal failure, the invention proposes that it should adopt a different design optimizing course according to different structures of generator winding, opens up a new way of scientifically making a solution of main protection configuration of a generator and reasonably selecting a led-out mode of neutral point-side branch and a solution of current mutual inductor configuration, corrects the previous wrong methods in the engineering, and provides a high- quality guarantee for safe operation of a large-scale generating set.

The invention discloses a three-phase decoupling load flow calculation method of a power distribution network based on a path matrix. The method comprises the following steps: firstly, adopting a symmetrical component method to perform sequence component decoupling on a three-phase unbalanced power distribution network to obtain zero sequence, a power distribution sequence network with positive sequence and negative sequence, and adopting a loop-analysis method based on the path matrix to perform one-phase-sequence component load flow calculation to obtain load flows of the three-sequence networks; and secondly, transforming sequence network load flows in a phase component mode by an inverse transformation principle of the symmetrical component method to obtain three-phase load flows. By using the method, a three-phase unbalanced power distribution network system is decoupled into zero sequence, positive sequence and negative sequence networks, so that large matrix manipulation in the three-phase load flow calculation is avoided, the calculated amount is decreased, and the calculation efficiency is improved. The method has the advantages of clear calculation process, simple programming and fast calculation speed. Finally, a 6-busbar test example verifies the correctness and good convergence; and the method is good in generality and practical applicability.

The invention discloses a three-phase decoupling power flow calculation method for a power distribution network containing multiple transformer branches. According to the characteristics of basically symmetrical three-phase line parameters, unbalanced three-phase load and the tree structure of the power distribution network, the method comprises the following steps: performing sequence component decoupling on the three-phase unbalanced network of the power distribution network by a symmetrical component method; in a power distribution three-sequence network model, transforming the transformer branches into the common branches by a phase transformation technology; and calculating the sequence network power flow of the power distribution system by a path matrix-based loop analysis method and transforming sequence component power flow into phase component power flow by an inverse transformation principle so as to realize three-phase decoupling power flow calculation of the three-phase unbalanced system of the power distribution network containing multiple transformer branches and reduce calculated quantity. The method is clear in calculation process, simple in programming and high in calculation speed. The correctness and high convergence property of the method are verified through 34 bus test calculation examples. The method has high generality and practicability.

The invention discloses a distributed generation power distribution network three-phase load flow calculation method taking a phase sequence mixing method into consideration. The distributed generation power distribution network three-phase load flow calculation method comprises the following steps that firstly, a power distribution network three-phase load model, a network phase sequence parameter model and a distributed power supply access model are built based on the phase sequence mixing method, an effective three-phase unbalance power distribution power network improved load flow calculation method is disclosed in a power distribution sequence network, and a sequence component method is fully utilized to process the advantages that a three-phase unbalance system has access to symmetrical distributed generation (DG) and PV nodes; and then PQ, PQ(V), PV and PI node type DG calculation models are deduced in detail and are induced into the discloses load flow calculation method. The distributed generation power distribution network three-phase load flow calculation method taking the phase sequence mixing method into consideration has the advantages of being clear in calculation process, simple to program, quick in calculation speed and good in convergence. Finally, the effectiveness and generality of the distributed generation power distribution network three-phase load flow calculation method are tested and verified through diffset. The distributed generation power distribution network three-phase load flow calculation method has good convergence and strong capacity of processing DG nodes and generating reactive power boundary cross.

A method and system for performing component fault problem close loop analysis are provided. The system establishes a component failure physics fault tree, converts the failure physics fault tree into a failure locating fault tree, establishes, a component fault dictionary with failure mechanism cause corresponding to failure characteristics and performs fault problem close loop analysis to the component according to the fault tree and the fault dictionary. By the method and system of the present disclosure, it is possible to locate the component fault in the internal physical structure by the failure locating fault tree, to give a clear failure path, to quickly identify the failure mechanism corresponding to the component failure mode by analysis of failure feature vector of the fault dictionary, and to determine the mechanism factors and influencing factors of relevant failure mechanism by the failure physics fault tree. Thus, targeted failure control measures are proposed to achieve fast and accurate locating and diagnosis to the electronic component failure.

The invention discloses a high-resolution phase locked loop. The high-resolution loop phase locked loop comprises an input frequency divider, a phase detector connected with a reference frequency divider, a low pass filter connected with the phase detector, a voltage-controlled oscillator connected with the low pass filter, a multiphase loop frequency divider connected with the voltage-controlled oscillator and a phase frequency detector, and an output frequency divider connected with the voltage-controlled oscillator. The high-resolution phase locked loop provides high-resolution and low-noise clock signals, and the multiphase loop frequency divider provides high-resolution feedback signals for the phase frequency detector. The high-resolution phase locked loop improves the resolution of output signals of a phase locked loop in conditions of reducing loop analysis difficulty and reducing resource consumption.

The invention discloses a three-phase decoupling load flow calculation method for a weakly meshed distribution network based on a sequence component method, comprising the following steps of: (1) carrying out three-phase load flow modeling on the weakly meshed distribution network based on the sequence component method and realizing three-sequence decoupling; and (2) building a three-phase decoupling load flow calculation method for the weakly meshed distribution network based on the step (1), wherein the three-phase decoupling load flow calculation method for the weakly meshed distribution network is a loop analysis method based on roads. Thereof, the algorithm keeps the advantages of a forward-backward sweeping method facing to branches; the convergence of the algorithm is not affected by the loop and the loop has better algorithm. Simultaneously, after adopting the three-sequence decoupling, the node number of the system load flow calculation is reduced; the load flow calculation quantity is reduced; and the calculation efficiency is improved. Finally, the accuracy and better convergence of the method provided by the invention are tested through 6-busbar and 33-busbar tests; the stronger loop processing ability is also tested; and the number of iterations is reduced along with the increased closed loop.

The invention discloses a loop-analysis method based linear method for calculating a three-phase power distribution network tide. The loop-analysis method based linear method comprises the following steps: obtaining the relation function of node voltages and node injection currents of a power distribution network according to a loop-analysis method; for a single-phase system, according to the relation function, obtaining node injection currents in an impedance anti-load, a constant current load, a constant power load and a mixed mode respectively, and introducing in the relation function for calculation to obtain node voltage values; and for a three-phase system, according to the relation function, obtaining node injection currents in an impedance anti-load, a constant current load and a constant power load, and introducing in the relation function for calculation to obtain node voltage values, wherein the three-phase system comprises a star connection load and a delta connection load. The method disclosed by the invention is high in calculation efficiency, few in occupied resources and high in calculation accuracy.

The invention relates to the field of welding, discloses an acquiring method of influence sensitivity of parameters on welding residual stress and deformation, and establishes a simulation model of the welding process of a welded joint. The method comprises the steps of selecting multiple performance arguments of a parent material, conducting experiments sequentially, and acquiring a parameter of each performance argument; adopting the parameter of each performance argument as a standard, and inputting multiple different parameter values within a set difference range of the argument into the simulation model sequentially; conducting the experiments again to acquire the parameter of a performance argument with the highest sensitivity, adopting the parameter of the performance argument with the highest sensitivity as the standard, and inputting multiple different parameter values within the set difference range of the performance argument with the highest sensitivity into the simulation model sequentially; comparing doublet characteristic curves corresponding to parameter changes of each performance argument, determining the performance argument with the highest sensitivity, and forming a close-loop analysis. The acquiring method of influence sensitivity of parameters on welding residual stress and deformation can establish a simulation database of core welding, improves the reliability of welding simulation, and reduces the cost of the testing experiments.

The invention discloses a method and a system for generating a virtual taxpayer fund loop. The method comprises the following steps: determining a falsely making and receiving taxpayer and corresponding social relation personnel; establishing a bank flow information table comprising the falsely making and receiving taxpayer and the bank flow information of the corresponding social relation personnel; generating a fund flow graph according to the bank flow information table, carrying out fund loop analysis operation on the fund flow graph by using a directed graph depth-first algorithm with a sliding time window, and displaying a virtually opened virtual fund receiving loop obtained by the analysis operation; the system comprises a bank flow information table, a social relation data table,an analysis unit and a display unit. The analysis unit is used for generating a fund flow graph according to the bank flow information table and analyzing a fund loop for the bank flow information inthe bank flow information table; according to the method and the system, the problems of low efficiency and few achievements of manual fund loop query are solved, and the case handling efficiency of related departments is greatly improved.

The invention relates to gyroscopes. In order to achieve production of gyroscope control loop hardware and integrate the function of analysis and testing of a gyroscope control loop, and according to the technical scheme, the gyroscope hardware production device comprises a testing component, a processing unit and a power supply device; the testing component comprises a high-precision two-axis positional rate turntable and a gyroscope mounted on the same; the processing unit comprises a data acquisition and control device, a data processing industrial personal computer, a digital rebalance loop and a control circuit; and the power supply device comprises an exciting power supply, a circuit board power supply and a gyroscope power supply. The method and the device are mainly applicable to design and production of the gyroscopes.

A method of controlling speed of an electric machine having a rotor and a stator is provided. The method may comprise the steps of monitoring a desired speed and a measured speed of the rotor, generating a torque command based on the desired speed and the measured speed, and controlling phase current to the stator based on a hybrid closed loop analysis of the torque command, the measured speed and an estimated position of the rotor. The estimated rotor position may be derived at least partially from the desired speed.

The invention discloses a main-distribution integrated online real-time closed-loop analysis method based on CIM / SVG, which is characterized by comprising the steps of establishing a main-distributionnetwork integrated model; analyzing the model to determine a loop closing path; and performing power flow calculation before and after loop closing on the loop closing path, and performing safety verification according to the closed-loop power flow calculation result to obtain a conclusion on whether the closed loop is successful or not and an adjustment suggestion. The invention has the advantages that the safety verification of the closed loop is provided through closed-loop analysis, the conclusion on whether the closed loop is successful or not is obtained, corresponding adjustment measures and suggestions are provided for the closed loop which does not pass the safety verification, the judgment information of whether the closed loop condition is met after the adjustment is provided,operation dispatchers are enabled to know the closed-loop operation result more visually and clearly through the closed-loop analysis, and meanwhile, the dispatchers can also be facilitated to realizethe closed-loop operation timely, effectively and quickly.

The invention discloses a drawing archive system with a simulation function, which adopts an object-oriented technology, is used in a windows environment, takes Visual Graph Window as a software development tool, and uses a TBL database to store graphic data and manage drawings. The system has the functions of a drawing tool and a drawing file management tool, and the drawing tool can be used fordrawing a drawing and storing the drawing in a computer in the form of a database file. This is also the basis of drawing management. And the management of the drawings is to classify and archive files of the drawings for a user to look up. The system comprises a drawing tool, a simulation library, a database, a picture library and a drawing management module. According to the system, the problemsof rapid modeling and rapid loop analysis in secondary loop simulation are solved, and rapid establishment of a secondary loop simulation system and rapid and accurate calculation of a system operation time loop measurement result are realized.

A method of controlling speed of an electric machine having a rotor and a stator is provided. The method may comprise the steps of monitoring a desired speed and a measured speed of the rotor, generating a torque command based on the desired speed and the measured speed, and controlling phase current to the stator based on a hybrid closed loop analysis of the torque command, the measured speed and an estimated position of the rotor. The estimated rotor position may be derived at least partially from the desired speed.

The invention relates to a multi-input-multi-output aircraft stability margin root locus equivalent determination method, which is used to solve the technical problem that the existing aircraft stability margin root locus determination method cannot determine different combinations. This method establishes the open-loop transfer function matrix of the multi-loop system, and connects a diagonal matrix with gain and lag phase angle to the open-loop transfer function matrix of the system, and obtains the stability margin analysis using the closed-loop transfer function matrix, thus obtaining The root locus scalar equation of the equivalent multi-loop stability margin analysis; the selection of different values ​​of the diagonal matrix artificially connected in series can analyze the phase margin and amplitude of the overall loop, a certain loop, and various combinations margin.

The invention discloses a distributed generation power distribution network three-phase load flow calculation method taking a phase sequence mixing method into consideration. The distributed generation power distribution network three-phase load flow calculation method comprises the following steps that firstly, a power distribution network three-phase load model, a network phase sequence parameter model and a distributed power supply access model are built based on the phase sequence mixing method, an effective three-phase unbalance power distribution power network improved load flow calculation method is disclosed in a power distribution sequence network, and a sequence component method is fully utilized to process the advantages that a three-phase unbalance system has access to symmetrical distributed generation (DG) and PV nodes; and then PQ, PQ(V), PV and PI node type DG calculation models are deduced in detail and are induced into the discloses load flow calculation method. The distributed generation power distribution network three-phase load flow calculation method taking the phase sequence mixing method into consideration has the advantages of being clear in calculation process, simple to program, quick in calculation speed and good in convergence. Finally, the effectiveness and generality of the distributed generation power distribution network three-phase load flow calculation method are tested and verified through diffset. The distributed generation power distribution network three-phase load flow calculation method has good convergence and strong capacity of processing DG nodes and generating reactive power boundary cross.

Method and system for performing close-loop analysis to electronic component failures are provided. The system establishes an electronic component fault tree of physics of failure (FTPF), converts the FTPF into a failure locating fault tree, establishes an electronic component fault dictionary with the cause of failure mechanism corresponding to failure characteristics, and performs close-loop analysis to the electronic component according to the fault tree and the fault dictionary. According to the disclosure, it is possible to locate the electronic component fault in the internal physical structure by the failure locating fault tree, to give a clear failure path, to quickly identify the failure mechanism corresponding to the electronic component failure mode by analyzing the failure characteristic vector in the fault dictionary, and to determine the mechanism factors and influencing factors of relevant failure mechanism by the FTPF, thereby achieving fast and accurate locating and diagnosis for the electronic component failure.

The invention relates to a method for analyzing turn-to-turn faults of a generator rotor based on a multiloop model, belonging to the technical problem of analysis and research of asymmetric fault problems of alternating current motor windings and relay protection of power system master devices. In the invention, based on a multiloop analysis method of an alternating current motor, a voltage and flux linkage equation is listed according to actual connection conditions of all stator and rotor loops in consideration of various space harmonics of air gap magnetic field caused by rotor faults, unbalance current inside a stator phase winding and the change of a topological structure of an excitation winding circuit; various loop parameters, particularly induction parameters related to an excitation winding generating turn-to-turn short circuit faults are accurately calculated, and a transient state calculation method and a stable state calculation method for the turn-to-turn short circuit faults of the excitation winding are provided. Experimental results prove the correctness and the accuracy of the two calculation methods and provide a quantified basis for designing turn-to-turn short circuit protection.

The invention discloses a loop-analysis method based linear method for calculating a three-phase power distribution network tide. The loop-analysis method based linear method comprises the following steps: obtaining the relation function of node voltages and node injection currents of a power distribution network according to a loop-analysis method; for a single-phase system, according to the relation function, obtaining node injection currents in an impedance anti-load, a constant current load, a constant power load and a mixed mode respectively, and introducing in the relation function for calculation to obtain node voltage values; and for a three-phase system, according to the relation function, obtaining node injection currents in an impedance anti-load, a constant current load and a constant power load, and introducing in the relation function for calculation to obtain node voltage values, wherein the three-phase system comprises a star connection load and a delta connection load. The method disclosed by the invention is high in calculation efficiency, few in occupied resources and high in calculation accuracy.

The invention discloses a method and system for generating a fund circuit of a false taxpayer. The method refers to determining the false taxpayer, the false taxpayer, and the corresponding social relationship personnel; establishing the false taxpayer and the corresponding social relationship The bank flow information table of personnel bank flow information, generates a capital flow graph according to the bank flow information table, and uses the directed graph depth-first algorithm with a sliding time window to perform capital circuit analysis and calculation on the capital flow graph, and the analysis operation The obtained virtual opening and receiving capital circuit is displayed; the system includes a bank flow information table, a social relationship data table, an analysis unit and a display unit; The bank flow information in the flow information table is used to analyze the capital circuit; the method and system solve the problem of low efficiency of manual query of the capital circuit and few results, and greatly improve the case handling efficiency of relevant departments.

The invention relates to a method for state estimation in the electrical field, in particular to a practical method for simple state estimation of a distribution network, comprising the following steps: (1) historical section data matching; (2) distribution network topology tree generation; (3) Switch remote signal identification; (4) Remote measurement completion; (5) Loop closure analysis; (6) Assessment statistics; (7) Daily load forecasting. This application provides a practical method for simple state estimation of a distribution network, so as to identify the remote signal value of the switch / knife switch, complement the switch telemetry value, and estimate the most reliable system operating state.

The invention relates to a project transaction closed-loop analysis method, which comprises the following steps of S100, monitoring the compliance condition of a project from two dimensions of a unitand time based on the project milestone time, and obtaining a special monitoring result; step S200, according to a special monitoring result, positioning a position where the abnormal action occurs, the monitoring result comprising a monitoring white list, a monitoring black list and a monitoring gray list; step S300, importing the monitoring result into an analysis tool, wherein the analysis toolautomatically removes a white list of the special monitoring result; and step S400, using a data visualization tool to visually configure and display the thematic monitoring result without the whitelist based on the user-defined rectification index and the newly-added index value.

The invention discloses a three-phase load flow calculation method of a weak looped distribution network comprising multi-type distributed power sources. Firstly, the effective three-phase load flow calculation method of a weak looped distribution network is put forward in a distribution sequencing network based on a sequence component calculation method and in combination with characteristics of the weak looped distribution network and a loop analysis of a road. Secondly, detailed formula derivation of iterative computation of distributed generation (DG) of a PQ node type, a PQ (V) node type, an OV node type and a PI node type is conducted and the easy formula is introduced into the load flow calculation method. The three-phase load flow calculation method of the weak looped distribution network comprising the multi-type distributed power sources can effectively process multi-type DG and the weak looped distribution network and is distinct in calculation procedure, simple in programming, and easy to achieve. In addition, the three-phase load flow calculation method of the weak looped distribution network comprising the multi-type distributed power sources retains strong points of rapid calculation and stable convergence of a forward-back substitution method catering to branch circuits. Finally, effectiveness and good convergence of the three-phase load flow calculation method of the weak looped distribution network comprising the multi-type distributed power sources is tested and verified by means of a IEEE (institute of electrical and electronic engineers)-37 generatrix test calculation case, and the three-phase load flow calculation method of the weak looped distribution network comprising the multi-type distributed power sources has good ability of processing the multi-type DG and the looped network.

The invention provides a demand closed-loop analysis method, system and device. The method comprises the steps of obtaining satellite scene data, obtaining demand data and carrying out demand timing coverage analysis and calculation. The method comprises the following steps: firstly, starting from two entrances of demand and scene data, carrying out small-amount operation in real time to obtain a certain incidence relation, and finally, summarizing and calculating coverage rate, observation times and observation duration, and sharing large calculation amount at the same moment in the prior art into small calculation amount at different moments, thereby reducing the calculation burden of a database and improving the calculation efficiency of the database. Therefore, the calculation efficiency is ensured, and the database pressure is reduced.