13 results about "Power system stabiliser" patented technology

The invention discloses a synchronous generator excitation method based on mathematical modeling and gain scheduling, and relates to the technical field of synchronous generator control, and the method comprises the steps: building a synchronous generator global dynamic mathematical model comprising the electromagnetic dynamic characteristics of a stator winding, a rotor winding and a damping winding through a modeling module; a discretization simulation platform is constructed in a Matlab / Simulink environment by utilizing a simulation module, model parameters are corrected, dynamic adjustment is realized through a gain scheduling excitation controller, an automatic voltage regulator (AVR) adopts PID (Proportion Integration Differentiation) control and comprises a voltage deviation integral separation strategy, and a power system stabilizer (PSS) dynamically adjusts parameters of a lead-lag compensator based on active power. According to the method, the deviation between a model and an actual system can be reduced by more than 30%, the electromechanical oscillation damping ratio within the rated power range of 10%-150% is increased by 25%-40%, the harmonic content of exciting current is reduced to be lower than 5%, the stability of an electric power system and the electric energy quality are remarkably improved, the engineering practicability is high, and the method is easy to transform and upgrade on an existing synchronous generator.

The invention discloses a VSG transient stability control method based on PSS power angle compensation and integral reactive loop cooperation, and the method comprises the steps: constructing an improved rotor motion equation compensation mechanism based on a power system stabilizer, and based on the dynamic parameters of the voltages vabc and pcc at a PCC point and the currents iabc and pcc flowing into the PCC point which are collected in real time, carrying out the compensation of the current iabc and pcc at the PCC point under the condition that the working condition is that the voltage of a power grid drops greatly. The dynamic characteristic of active power is ensured; constructing a PSS parameter optimization method based on zero point position constraint; an integral link is embedded in the traditional voltage-reactive droop characteristic, integral reactive loop control is constructed, and steady-state voltage deviation is eliminated; the output compensation power angle delta and the output voltage amplitude E are cooperatively applied and converted into dq-axis voltage components Ed and Eq, the dq-axis voltage components Ed and Eq are sent to a voltage and current double closed loop, a driving signal is generated through SVPWM, and the stability of the system is enhanced.

Disclosed are a method and system for verifying a low-frequency oscillation damping control effect of a governor power system stabilizer (GPSS), relating to the technical field of power systems. The method includes: selecting a wiring working condition for a fault-free disconnection test, and constructing a unit test working condition; performing the fault-free disconnection test on an outgoing line of a power plant, and collecting an electromagnetic power fluctuation recording curve; and comparing low-frequency oscillation damping effects under different GPSS settings, evaluating the effects, and performing a cyclic test. A success rate of the test is increased, safety of the test is improved, and the overall stability and anti-oscillation capacity of the system are improved in the disclosure.

The application discloses a parameter setting method and system of PSS based on complex domain vector synthesis, and belongs to the technical field of power system automation and control. The method comprises the following steps: obtaining an open-loop frequency response, and extracting a phase lag characteristic curve of a channel; based on a complex domain vector synthesis model and the phase lag characteristic curve, a complex response calculation formula is constructed, a total open-loop phase is defined, a parameter vector is set and a parameter feasible region is determined, a target compensation phase is set, a weighted comprehensive phase error target function is defined, and a boundary value is set; the weighted comprehensive phase error target function is taken as a fitness function, parameter space searching is performed, and a parameter vector that minimizes the fitness function is solved; the parameter searching process of the global optimization algorithm is optimized; the optimal parameter set is verified in multiple dimensions and vector synthesis visual analysis is performed, and parameter setting of a power system stabilizer is completed. The application has correct principles, relatively high efficiency and accuracy in processing, and high engineering applicability.

The invention discloses a new energy power grid frequency stability detection method considering the dynamic state of a power system stabilizer, and the method comprises the steps: employing a linearization equation to represent the voltage influence relation of a power grid between source and load nodes, deducing a voltage-power sensitivity function, combining the sensitivity information of an initial operation point of a system, and calculating the frequency stability of the power grid when the voltage of a generator changes. Voltage variation of each load node; a polynomial load model in an exponential form is adopted to represent diversified loads in the system, the active power variation of the loads is linearized according to the load model, then the active power increment of the loads of the system is obtained, and a voltage-active power dynamic model of the loads of the source network is established; on the basis of a traditional SFR model, a voltage-active dynamic model of a source network load is superposed, a PSS-containing voltage-active new energy power grid frequency response model is constructed, and the influence of voltage-active dynamics on system frequency stability is analyzed; and solving the new energy power grid frequency response model containing the PSS to obtain frequency response, and evaluating the safety in combination with a frequency safety requirement.

The invention belongs to the technical field of multi-machine power systems, and particularly discloses a parameter optimization method and device for a multi-machine power system stabilizer, equipment and a product. According to the method, the damping ratio corresponding to the key electromechanical oscillation mode is calculated; generating a multi-dimensional target optimization function according to the damping ratio, the target deviation parameter and the comprehensive target function; and on the basis of a target weighted average optimization algorithm, searching an optimal parameter combination meeting an optimization constraint condition function according to the multi-dimensional target optimization function. Through the mode, the key electromechanical oscillation mode is identified by using the current oscillation signal of the multi-machine power system, the comprehensive target function which takes the damping ratio into account and takes multiple indexes into account is used when the multi-dimensional target optimization function is generated, then iterative solution is performed based on the target weighted average optimization algorithm, and the optimal parameter combination is searched, so that the multi-dimensional electromechanical oscillation mode is obtained. Therefore, the efficiency and the quality of parameter optimization can be effectively improved, and the robustness of the power system stabilizer during low-frequency oscillation suppression is further improved.

The application provides a method and device for determining an inertia time constant of a generator set. The method comprises: performing step disturbance on a terminal voltage of a to-be-tested generator based on a first inertia time constant and a first preset threshold, amplifying a synthesized mechanical power integral of a power system stabilizer by a first preset coefficient, and recording a first waveform diagram to obtain a first target value based on a first pole value of the first waveform diagram; updating the first inertia time constant based on a preset adjustment step and the first target value to obtain a second inertia time constant, and then determining a second waveform diagram and a second target value; correcting the second inertia time constant based on a preset adjustment step, the first target value and the second target value to obtain a corrected inertia time constant, and then determining a third waveform diagram and a third target value; and obtaining a target inertia time constant when an absolute value of the third target value is less than or equal to a second preset threshold. The method solves the problem of a large error of a unit inertia time constant in the prior art.

The invention belongs to the technical field of electric power system stability control, and particularly discloses a multi-target cooperative control electric power system stabilizer and an obtaining method thereof, and the obtaining method specifically comprises the steps: building a macro variable based on a rotating speed deviation, an electric power deviation and a generator terminal voltage deviation, and then obtaining a multi-target cooperative control electric power system stabilizer according to an electric power system state equation of n generators and the macro variable; solving the control law to obtain a power system stabilizer; wherein the power system is a multi-machine multi-area interconnected power system. The method can improve the dynamic response speed, robustness and low-frequency oscillation suppression capability of the power system stabilizer and enhance the stability of the generator terminal voltage, and is suitable for the operation condition of an actual power system.

The application discloses a kind of multi-branch power system stabilizer suitable for wind and fire bundling system, the stabilizer uses the collaborative control structure of low-frequency branch and subsynchronous branch parallel, pass through the second-order filter of low-frequency branch, direct current compensation and lead-lag module inhibits the low-frequency oscillation of 0.1Hz-4Hz frequency band, and subsynchronous branch extracts subsynchronous risk mode based on the inverse transformation matrix of generator shaft system torsional vibration mode quantity, combined with phase compensation module, and damping signal is injected directionally to inhibit the subsynchronous oscillation of 10Hz-50Hz frequency band.Parallel output module is connected to excitation regulator after the superposition of multi-branch signal is limited, and electromagnetic torque is dynamically adjusted, to realize wide frequency domain oscillation suppression.The application is controlled by mode quantity direction, parameter self-adaptive setting and multi-branch dynamic decoupling, solves the problem, such as the insufficient suppression ability of multiple frequency bands of traditional power system stabilizer in wind and fire coupling system, parameter mismatch and controller conflict, significantly improves the stability and robustness of new energy high penetration rate power grid.

This invention provides an analytical method for the influence of the excitation system of a hydropower unit on ultra-low frequency oscillations. Based on a multi-unit system, an equivalent single-unit, single-load model for analyzing ultra-low frequency oscillation modes is constructed. An improved four-unit, two-zone system model of the excitation control system based on a power system stabilizer is constructed and trained. The transfer function in the equivalent single-unit, single-load model is solved using the trained improved four-unit, two-zone system model to obtain the poles of the transfer function, and the mechanism by which the excitation system influences ultra-low frequency oscillations is analyzed. This invention analyzes the mechanism by obtaining the eigenvalues ​​corresponding to the oscillation modes of the improved four-unit, two-zone system, providing a basis for studying the mechanism by which the excitation system influences ultra-low frequency oscillations. Furthermore, transfer function and damping torque analyses are performed for cases where network losses are ignored and the voltage regulation effect of the load is considered, providing a more detailed analysis of the mechanism by which the excitation system of a hydropower unit influences ultra-low frequency oscillations, thus filling the gap in the study of how the excitation system suppresses ultra-low frequency oscillations.

The invention provides a voltage control method and device for island conversion of a direct-current power transmission system, the voltage control method is applied to a power system stabilizer of the direct-current power transmission system, and the method comprises the following steps: if the frequency input to a power system controller is greater than a preset threshold value, judging a direct-current island conversion mode; if the DC island conversion is the active island conversion, closing a frequency signal branch of the power system controller, keeping a power signal branch of the power system controller effective, and restoring the frequency signal branch of the power system controller to be effective after the DC power transmission system enters the DC island state; and if the DC island conversion is passive conversion and the island signal is judged to be true at the output end of the power system controller, reducing the amplitude of the output end of the power system controller according to a preset proportion, and recovering the amplitude of the output end of the power system controller after the DC power transmission system enters the DC island state.

The invention discloses a method, a device and equipment for suppressing subsynchronous torsional vibration of a shaft system of a steam turbine synchronous generator unit and a storage medium, which are used for solving the technical problem that the steam turbine synchronous generator unit has the risk of subsynchronous torsional vibration of the shaft system. The method comprises the following steps: establishing a mass-spring system model of the shaft system of the steam turbine synchronous generator unit; the mass-spring system model and a preset synchronous generator set equation are combined, and a critical stable torsional vibration mode is determined; inputting the modal rotation angle increment corresponding to the critical stable torsional vibration modal into an additional control loop of a preset power system stabilizer, and outputting a compensation signal; and superposing the compensation signal with a basic control output signal of the power system stabilizer to obtain a suppression signal which is used for suppressing the shaft system subsynchronous torsional vibration of the steam turbine synchronous generator set.

Provided in the present disclosure is a method for determining a control parameter stability region of a power system stabilizer (PSS) of a generator. The method comprises the following steps: S1, acquiring parameters of a generator, an excitation system, a PSS and a grid-connected power system; S2, on the basis of the parameters, determining a system state variable x, a control variable and an intermediate variable u, and on the basis of a system stable-state calculation result, initializing the generator, the excitation system, the PSS and the grid-connected power system; S3, obtaining an operating power system model; S4, extracting a small-disturbance stability analysis model; S5, constructing and initializing a system control parameter space; S6, performing a search and evaluating the trajectory stability of each operating point in a specified direction; and S7, adjusting a control parameter search direction, and determining a set of control parameter stability region boundaries.