17 results about "System analysis" patented technology

The invention discloses a short-circuit current calculation method based on a power frequency model, and belongs to the technical field of power system analysis. The method comprises the following steps: collecting basic parameters of a power system under power frequency, wherein the basic parameters comprise system rated voltage, impedance parameters of each element and a system topological structure; constructing a power frequency equivalent model of the power system based on the power frequency parameters, and forming equivalent circuit representation; determining the type and position of a short-circuit fault; based on a power frequency equivalent model, a short-circuit current value is calculated through a circuit analysis technology, an asymmetric fault is processed by adopting a symmetric component method, and the influence of transition resistance can be considered; and outputting a short-circuit current calculation result for system protection or equipment verification. According to the method, the calculation process is simplified, the calculation efficiency is improved, the calculation precision under the power frequency is ensured, and the method has high engineering practical value.

The application belongs to the field of wind turbine fault identification, and relates to a fault identification method and system based on a doubly-fed wind turbine, comprising: obtaining operation data of the doubly-fed wind turbine, and processing the operation data to obtain operation time series data set; obtaining associated feature labeling data based on the association between the operation data; constructing a multi-system collaborative integration model and initializing to obtain an initial collaborative integration model; training the initial collaborative integration model to obtain a trained collaborative integration model; inputting a current operation feature vector of the doubly-fed wind turbine into the trained collaborative integration model to obtain generation error and prediction error; calculating an initial fault score based on the generation error and the prediction error, and determining a system of the doubly-fed wind turbine that has occurred a fault based on the initial fault score; to solve the limitation of single-system analysis, improve fault identification accuracy, and determine the main system and the secondary system that cause the fault.

The invention relates to the technical field of circuit system analysis, in particular to a method, a system and equipment for measuring parameters of a transformer. An excitation current source is applied to the primary side of a to-be-measured transformer, an open circuit of the secondary side is kept, the alternating voltage of the secondary side is measured, the real part and the imaginary part of the ratio of the alternating voltage of a secondary side winding to the alternating input current of a primary side winding are calculated, and the excitation resistance and the excitation inductance of a magnetic core are obtained according to the real part and the imaginary part. Stopping applying excitation, measuring port resistance and inductance from a primary side port, and calculating primary side leakage resistance and leakage inductance in combination with obtained excitation parameters; and opening the primary side, measuring the port resistance and inductance from the secondary side port, and calculating the secondary side leakage resistance and leakage inductance in combination with excitation parameters. The testing method is easy and convenient to operate, the calculation process is simplified, and the parameter measuring precision of the transformer is effectively improved.

This invention relates to the field of power system analysis, specifically to a method for determining the transient stability of a power grid based on a critical credibility index. The method includes: calculating the transient instability probability using real-time acquired transient response trajectories of electrical quantities at the initial stage of a fault and a trained transient stability discrimination model; predicting a transient stability label based on the transient instability probability; evaluating the predicted transient stability label to obtain the final transient stability discrimination result. This invention significantly improves the accuracy and generalization ability of the transient stability discrimination model by constructing an electromechanical transient simulation dataset covering multiple operating modes and fault types, and using transient response trajectories of electrical quantities as core feature inputs. The introduction of a critical credibility index quantifies the uncertainty of the model output results, reducing the possibility of instability conditions being misclassified as stable conditions, and improving the conservatism and accuracy of the discrimination results.

The invention provides a method and system for predicting the separation time of an industrial machine through a laboratory electromagnetic classificator test. The method comprises the following steps of separation preparation, ore pulp preparation, cyclic separation, sampling, ore discharging, system closing, analysis and test and test data processing. The system further comprises a control cabinet and an electromagnetic classificator, a concentrate outlet of the electromagnetic classificator is connected with the ore feeding groove and the concentrate collecting groove, a discharging opening of the ore feeding groove is connected with a feeding opening of the electromagnetic classificator, and a tailing outlet of the electromagnetic classificator is connected with the tailing collecting groove to control material conveying and start and stop of stirring mechanisms in the ore feeding groove and the tailing collecting groove. According to the method, real prediction of the industrial indexes of the electromagnetic classificator is completed, the problem of poor concentrate grade indexes of the laboratory electromagnetic classificator is solved, an accurate basis is provided for special design and model selection of industrial large-scale equipment, and substandard mineral separation effect or investment loss caused by wrong specification and model selection can be avoided; debugging of dressing plant equipment is guided, the debugging period is shortened, and good industrial indexes are rapidly obtained.

The embodiment of the invention provides a wind power plant internal short-circuit current analytical calculation method and system, and belongs to the technical field of power system analysis. The method comprises the following steps: acquiring electrical topological data and operation state data of a wind power plant, and constructing a wind power plant equivalent network model based on the electrical topological data; constructing a wind turbine generator short-circuit injection model, and generating a short-circuit analysis model; preset short-circuit working condition parameters are obtained, a short-circuit working condition is applied to the short-circuit analytical model, short-circuit current is solved in an analytical calculation mode, and an initial short-circuit current analytical result is output; and correcting the wind turbine generator short-circuit injection model, performing analytical calculation on the short-circuit analytical model again under the constraint of the corrected wind turbine generator short-circuit injection model, and outputting a target short-circuit current analytical result. According to the method, an injection model correction mechanism based on an initial short-circuit current result is introduced into an analytic calculation framework, so that consistency analytic calculation of short-circuit current distribution and network equivalence relation of different electrical positions in the wind power plant is realized.

The invention relates to the technical field of circuit system analysis, in particular to a method, a system and equipment for measuring parasitic parameters of a high-frequency transformer. Voltage is applied to the primary side of the transformer, the secondary side is open-circuited, the secondary side voltage is measured, and the real part and the imaginary part of the ratio of the secondary side voltage to the power supply voltage are calculated; stopping power supply, measuring resistance and inductance of a primary side port, and obtaining magnetization inductance, magnetic core equivalent resistance, primary side leakage inductance and leakage resistance in combination with the ratio parameters; and opening the primary side, measuring the resistance and the inductance of the secondary side port, and calculating the leakage resistance and the leakage inductance of the secondary side by combining the measured parameters. Complex electrical connection is avoided, operation is easy and convenient, measurement errors are small, parasitic parameters of the transformer under different frequencies can be measured, and therefore the dynamic change rule of the parasitic parameters of the high-frequency transformer along with the frequencies is obtained.

This invention addresses the shortcomings of existing technologies by providing a method for parameter identification and SOH estimation of a first-order RC equivalent circuit model for automotive lithium batteries. The method includes the following steps: 1) Analysis of the principle of unknown parameter identification in chaotic systems; 2) Connecting electronic components such as load-controlled memristors as loads to the output of the first-order RC equivalent circuit model to establish a fourth-order chaotic system; 3) Analyzing the dynamic characteristics of the fourth-order chaotic system, including its phase trajectory diagram and time-domain waveform diagram; 4) Constructing an adaptive control law for the unknown parameters of the fourth-order chaotic system to achieve parameter identification and SOH estimation of the first-order RC equivalent circuit model. This invention's method exhibits high accuracy, stability, higher convergence speed, and stronger nonlinear prediction capabilities.

The invention discloses a power distribution network power electronic equipment broadband domain impedance characteristic test and stability evaluation method, a system, equipment and a medium, and relates to the technical field of power system analysis and power electronic equipment test, and the specific steps are as follows: injecting a controlled broadband disturbance signal at an access point of tested power distribution network power electronic equipment; the method comprises the steps of collecting voltage data and current data before and after disturbance, calculating equipment side impedance and power grid side impedance, evaluating single-equipment access stability by adopting a frequency domain stability analysis method, establishing a node admittance matrix to evaluate multi-equipment access stability, establishing an equipment impedance change trend calculation formula to calculate an equipment impedance change rate, and calculating the equipment impedance change rate. And outputting a comprehensive stability evaluation result of the power distribution network power electronic equipment. According to the method, broadband domain impedance online testing and stability evaluation of the power distribution network power electronic equipment under the actual operation working condition can be achieved, meanwhile, the trend that the equipment impedance changes along with time or the working condition can be recognized, and early warning is conducted for potential instability risks.

The invention relates to the field of power system equipment management, in particular to a power plant electrical equipment intelligent predictive maintenance and health management system which comprises an electrical equipment operation data acquisition module, a state monitoring module, a fault prediction module and an expert decision module. An equipment state manifold model is constructed in combination with a differential geometry theory, a geodesic evolution prediction system is utilized to analyze a state trajectory evolution trend, a potential fault type and failure time are identified through a critical region identification and specific point analysis system, and the core innovation lies in mapping an equipment state to a differential manifold space. Technical upgrading from linearity to nonlinearity, from point monitoring to trajectory analysis and from determinacy early warning to topological structure analysis is realized, and a scientific decision basis is provided for power plant electrical equipment management.

The invention relates to the technical field of flywheel energy storage systems, in particular to a consistency control method and system for a distributed flywheel energy storage system, and the method comprises the following steps: based on the flywheel energy storage system, analyzing the power and change trend of an energy storage unit, discriminating a load signal, comparing the power and rotating speed of multiple units in real time, triggering synchronous adjustment, and compensating output difference. And finally, optimizing the response consistency to obtain a consistency adjustment reference. According to the invention, through dynamic comparison of power difference and rotation speed change, multi-unit operation states are brought into an overall determination view angle, dynamic synchronization of energy distribution and output targets is realized, and after units with low energy utilization are screened, target correction is automatically completed, so that the adjustment action is finer, and output current and rotation speed parameters are linked; a self-adaptive compensation mechanism is formed for power output offset, a dynamic cooperation relation of units in a global situation is formed, and after an adjustment action is finished, a self-adjustment and discrimination mechanism is improved through comparison of a response rate and a state.

This invention relates to the field of mechanical equipment testing equipment technology, and discloses a gear fault detection and analysis method and detection system. The analysis method includes the following steps: preprocessing the vibration acceleration signal and rotational speed signal of the gear fault test bench under preset working conditions to form an intrinsic dataset; performing variational mode decomposition on the data in the intrinsic dataset to obtain a modal component set; reconstructing the modal component set based on the spectral kurtosis map method to form an extreme kurtosis set; processing the extreme kurtosis set using an adaptive time-domain synchronous averaging method, and then superimposing the processed dataset into a frequency domain enhancement; based on the envelope spectrum fault characteristics, analyzing the superimposed frequency domain enhanced dataset to obtain the fault characteristic frequency. This invention addresses the problem that traditional signal analysis methods cannot directly analyze gearbox faults under complex working conditions, and proposes a method and system for obtaining early fault characterization of gears, effectively suppressing noise interference in nonlinear and non-stationary complex signals.

The application relates to an inverter grid-connected parameter stability domain identification method and device based on bifurcation characteristics, which comprises the following steps: establishing a generalized swing equation based on the differential algebraic equation of different inverters; deriving a unified standard form and equivalent parameters suitable for bifurcation analysis; systematically analyzing the boundary conditions of generalized saddle-node bifurcation, Hopf bifurcation and homoclinic bifurcation, and constructing the area division in the parameter space with different dynamic behaviors; based on the system equilibrium point and the manifold characteristics in different areas, the stability domain of the inverter control parameters and electrical parameters is accurately identified by combining the Melnikov function analysis result. The method uses the principle of nonlinear dynamics to derive the bifurcation boundary conditions of the inverter grid-connected system, construct the typical area with different dynamic structures in the parameter space, and then identify the parameter stability domain under different operating conditions. The multi-parameter stability problem of a complex system can be reduced to the boundary judgment of a few key parameters, and the efficiency and accuracy of the stability domain identification are greatly improved.

The invention relates to the field of electric power, and discloses a method for evaluating and analyzing the deep peak regulation capability of a coal-fired power generating unit, which is used for introducing a nonlinear dynamic system theory into the field of evaluating the deep peak regulation capability of the coal-fired power generating unit. According to the method, the dynamic behavior of the system is described by using the phase space reconstruction technology, the stability boundary is quantitatively analyzed in combination with the Lyapunov index and the Hamiltonian system theory, and the evaluation model considering the multi-time scale coupling effect is established. The peak regulation limit is accurately recognized from the dynamic characteristic level in the unit, the problems that in an existing method, the mechanism is not clear, system analysis is isolated, and real-time performance is poor are solved, and guarantee is provided for improving the peak regulation capacity of the unit, guaranteeing safe and stable operation of a power grid and promoting renewable energy consumption.

The application discloses a new energy grid-connected optimal configuration method considering power electronic transient support limits, belongs to the technical field of power system analysis, and comprises the following steps: step 1, evaluating the physical limits and control saturation limits of converter voltage, current, power and other electrical quantities to obtain a maximum working interval; and step 2, finding main factors influencing the transient stability of the converter by comprehensively considering the physical and control limits and comparison, wherein the optimal method proposed in the application considers the fundamental limiting factors influencing the transient support capability of the converter, solves the deficiency that the idealized results are caused by the fact that the converter support capability limits are not considered in the conventional new energy grid optimal configuration method, and makes the analysis results more consistent with the actual operation of the power grid.

This invention discloses a power system analysis method based on power flow calculation across all voltage levels of the main and distribution networks, belonging to the field of power system power flow analysis technology. The method includes: hierarchical modeling of the main and distribution networks according to voltage levels to construct a unified structured topology model; constructing coupled local recursive power flow models at the main and distribution network layers based on a recursive nesting method to achieve cross-layer collaborative solution; real-time acquisition of distribution network operating status and dynamic correction of power flow parameters; and establishing a multi-objective optimization model based on voltage trends to generate the optimal power supply reconfiguration strategy. This invention integrates the main and distribution network topology, electrical parameters, and real-time data to establish a unified structured data model, recursively solves the problem, and introduces a dynamic coupling correction factor to improve the accuracy of power flow calculation. Combined with state feedback, it achieves dynamic adaptation of the local recursive power flow model, constructs a multi-objective optimization model based on voltage trends, optimizes power supply paths, and improves the accuracy, stability, and intelligence level of power grid operation.

The invention discloses a line impedance calculation and anomaly study and judgment method based on data correction of an electric terminal and an electric energy meter, and relates to the technical field of analysis, operation and maintenance of an electric power system. The method comprises the following steps: carrying out abnormal value detection and polynomial fitting correction on voltage and power time sequence data collected by an electric energy meter; based on the corrected voltage data, preliminarily identifying a user-transformer relation through principal component analysis and Gaussian mixture model clustering, and correcting a real subordinate transformer area of a user in combination with a Pearson's correlation coefficient; constructing an impedance optimization model according to the corrected topology and the corrected data, and solving line impedance parameters by adopting a doliolaria optimization algorithm; and finally, based on historical impedance data, carrying out anomaly study and judgment through a dual mechanism of'isolated forest initial check + confidence interval recheck '. According to the method, the original data quality and the topology identification accuracy are improved, the robustness calculation of the impedance parameters is realized, and the abnormal misjudgment rate is effectively reduced.