12 results about "Susceptance" patented technology

The invention discloses a residual sensitivity matrix-based power distribution network parameter anomaly positioning and correction method. The method comprises the following steps of: determining the type of each branch of a power distribution network and then obtaining a to-be-checked parameter of each branch; obtaining actual values of active power and reactive power of each branch in the power distribution network; obtaining conductance and susceptance of each branch, calculating theoretical values of active power and reactive power of each branch according to the conductance and susceptance of each branch and the to-be-checked parameter data, and calculating an active power residual error and a reactive power residual error of each branch; constructing a sensitivity matrix and a measurement residual vector, establishing a regular equation through the sensitivity matrix and the measurement residual vector, and solving the regular equation to obtain a line length deviation value and a transformer transformation ratio deviation value; and correcting the line length and the transformer transformation ratio. According to the invention, high-precision, anti-interference and stable identification of the line length and the transformation ratio of the transformer is realized.

The invention discloses an island micro-grid load flow calculation method, system and device and a storage medium, and the method comprises the steps: obtaining the resistance, reactance and susceptance of a power transmission network line and a transformer at a rated frequency, and building a node power model considering the frequency characteristics; obtaining an active droop coefficient and a reactive droop coefficient of the distributed power supply, and further establishing a droop control model for load flow calculation; obtaining a dependency relationship of power of a load element on voltage and frequency, and further establishing a load model considering frequency characteristics; simultaneously establishing the three models to obtain an overall model for island micro-grid load flow calculation, and taking the system frequency as a variable to be solved; and determining the initial value of the system frequency, solving the overall model through iteration until the load flow calculation is converged, and obtaining the steady-state values of the voltage, the phase angle and the system frequency of each node. And the characteristic description of the distributed power supply and the load flow calculation result are more accurate.

The invention relates to a static voltage stability evaluation method, device and equipment for new energy through a flexible direct current delivery system. The method comprises the steps of obtaining a full-order power grid susceptance matrix, a plurality of pieces of measurement data and a network topology and operation mode of the new energy through the flexible direct current delivery system; calculating to obtain a complex power matrix according to all measurement data; performing deletion and elementary row / column transformation processing on the full-order power grid susceptance matrix according to the network topology and the operation mode to obtain an updated power grid susceptance matrix; calculating static voltage stability margin index data according to the complex power matrix and the updated power grid admittance matrix; calculating the static voltage stability margin according to the static voltage stability margin index data; and according to the static voltage stability margin, judging whether the static voltage of the new energy in the operation period of the flexible direct current delivery system is stable or not. According to the method, the static voltage stability evaluation of the new energy in the operation period of the flexible direct current delivery system is realized through the static voltage stability margin, and the evaluation accuracy is improved.

The invention relates to the technical field of power grid control, in particular to a no-droop control method and system for access of complete new energy to an isolated microgrid and a test platform, and the method comprises the steps: obtaining electrical network parameters, inter-node communication network parameters and distributed power capacity parameters of the isolated microgrid; constructing a susceptance matrix based on electrical network parameters, constructing a Laplacian matrix based on communication network parameters, and constructing a power matrix based on distributed power capacity parameters; constructing a system matrix based on the susceptance matrix, the Laplacian matrix, the power matrix, a preset filter time constant and a controller gain; solving a state equation of the micro-grid control system based on the system matrix to obtain a state vector representing active power output of the distributed power supply of each node; and generating a control signal for driving the distributed power supply of each node based on the state vector, and controlling each node to distribute loads according to the capacity proportion of the distributed power supply. According to the invention, accurate and stable control of the isolated microgrid can be realized.

Disclosed in the present invention are a variable admittance-based fault current limiting system and method for a grid-forming converter. The system comprises: a power calculation module, an excitation link module, a virtual rotor module, a coordinate transformation module, a dual-loop control module, and a space vector pulse width modulation module. The power calculation module is used for calculating active power and reactive power of a current power grid; the excitation link module is used for performing steady-state stepless variable susceptance control on the basis of the calculated reactive power, so as to adjust the electromotive force of the current power grid; the virtual rotor module is used for performing transient stepped variable conductance control on the basis of the calculated active power, so as to adjust the phase angle of the current power grid; the coordinate transformation module is used for converting the adjusted electromotive force and phase angle into electromotive force components in a direct current coordinate system; the dual-loop control module is used for generating and calculating a current instruction on the basis of the converted electromotive force components; and the space vector pulse width modulation module is used for generating a modulation signal to guide operation of a switching device.

The application discloses a power distribution network parameter abnormality positioning and correction method based on a residual sensitivity matrix, and the method comprises the following steps: determining the types of each branch of the power distribution network to obtain to-be-checked parameters of each branch; obtaining actual values of active power and reactive power of each branch in the power distribution network; obtaining conductance and susceptance of each branch, and calculating theoretical values of the active power and the reactive power of each branch according to the conductance, the susceptance and the to-be-checked parameter data of each branch, and calculating active power residuals and reactive power residuals of each branch; constructing a sensitivity matrix and a measurement residual vector, and establishing a normal equation through the sensitivity matrix and the measurement residual vector, and solving the normal equation to obtain line length deviation and transformer ratio deviation; and correcting the line length and the transformer ratio. The application realizes high-precision, anti-interference and stable identification of the line length and the transformer ratio.

The invention belongs to the technical field of power system measurement and modeling, and particularly relates to a line parameter identification method based on non-intrusive PMU prior error analysis and correction, which comprises the following steps: calibrating a PMU through a synchronous standard source, obtaining measurement errors of a voltage amplitude, a phase angle and a current phase angle, and counting distribution characteristics of the measurement errors; establishing an error mapping relation between a true value known scene and an unknown scene to quantify the influence of the operation state on resistance, reactance and susceptance identification; and correcting the identification parameters according to the error distribution pattern, and adaptively selecting arithmetic mean, truncation mean, Huber estimation or GMM-EM weighted average methods to determine final parameters according to the error distribution pattern. According to the method, PMU measurement errors can be effectively compensated, and the precision and robustness of parameter identification in scenes such as a short circuit are remarkably improved.

The invention discloses a harmonic power flow analysis method considering background harmonic voltage, which comprises the following steps of: establishing a harmonic equivalent circuit comprising a background harmonic voltage source and a plurality of nonlinear loads, and establishing a node admittance matrix according to the equivalent circuit; a method of establishing a harmonic equivalent conductance and harmonic equivalent susceptance model is used to decompose harmonic current at a node, and harmonic current reflecting nonlinear characteristics of a harmonic source is extracted. The nonlinear load harmonic current is used as node injection harmonic current, each harmonic voltage at the node is solved by adopting a current injection type retaining nonlinear algorithm, and when the convergence condition is met, the harmonic voltage value of each node under the condition of considering the background harmonic voltage can be solved. And analyzing the transmission characteristics of harmonic waves in the power distribution network system according to the obtained node harmonic voltage. According to the method, the harmonic load flow calculation can be performed on the power distribution network under the condition of considering the background harmonic voltage to obtain an accurate harmonic voltage value in the system, so that the harmonic transfer characteristic is analyzed, and the application is wide.

The application discloses a single-phase grounding fault control method and system, wherein the method comprises the following steps: collecting first zero sequence voltages, equivalent ground conductance and equivalent ground susceptance of all feeder lines of a power distribution network; analyzing all the first zero sequence voltages to determine corresponding respective fault lines; collecting first zero sequence susceptances of active inverters, second zero sequence susceptances of arc suppression coils and third zero sequence susceptances of respective feeder lines; determining single-line compensation zero sequence susceptances of each fault line; collecting zero sequence currents and second zero sequence voltages of respective pole switches; calculating self zero sequence susceptances of each pole switch; determining fault types of each pole switch; and simulating and verifying fault control measures corresponding to each fault line obtained by each fault type and executing the fault control measures. The single-phase grounding fault control method and system provided by the embodiment of the application improve the real-time performance of single-phase grounding fault control.

The invention discloses an intelligent voltage power meter monitoring method based on real-time data acquisition, and relates to the technical field of electrical measurement, and the method comprises the steps: obtaining equivalent conductance and equivalent susceptance through inner product operation based on a discrete voltage sequence and a discrete current sequence, and generating an orthogonal physical component through an FBD orthogonal decomposition theory; establishing a discrete pixel coordinate sequence, and filling the orthogonal physical component into the discrete pixel coordinate sequence to generate a real-time Fryze power manifold image; scaling the real-time Fryze power manifold image into a standardized tensor, inputting the standardized tensor into an embedded end ShuffleNet V2 model for hierarchical processing, and outputting a high-dimensional manifold feature vector; and calculating a feature similarity score based on the high-dimensional manifold feature vector, and obtaining a fault type in combination with a dynamic anomaly threshold. According to the method, abstract electrical parameters are converted into structured images, the non-linear feature capturing capability is enhanced, and the effect of improving the fault feature analysis precision of the intelligent sensor is achieved.

The application belongs to the technical field of power system measurement and modeling, and particularly relates to a line parameter identification method based on non-intrusive PMU prior error analysis and correction, comprising the following steps: calibrating the PMU through a synchronous standard source, obtaining the measurement errors of voltage amplitude, phase angle and current phase angle, and statistically analyzing the distribution characteristics; establishing an error mapping relationship between the true value known scene and the unknown scene to quantify the influence of the operating state on the resistance, reactance and admittance identification; correcting the identified parameters accordingly, and selecting the arithmetic mean, the truncated mean, the Huber estimation or the GMM-EM weighted average method to determine the final parameters according to the error distribution form. The application can effectively compensate for the PMU measurement error, and significantly improve the accuracy and robustness of parameter identification in the short line and other scenes.

A method for solving multiple OPF equations of an AC electrical power system with plural topologies and admittances is provided. The method includes determining a continuous admittance space to embed the plural topologies, determining a plurality of voltage magnitudes and a plurality of voltage phase angles of the plurality of buses by a deep neural network, and reconstructing an active power generation and a reactive power generation using power flow equations according to the plurality of voltage magnitudes, the plurality of voltage phase angles, and the load inputs. The continuous admittance space is an admittance matrix of a plurality of line admittances each having a default admittance computed using a conductance and a susceptance of the plurality of branches. The deep neural network receives the load inputs and the plurality of line admittances as inputs.