48 results about "Transient stability assessment" patented technology

The invention belongs to the technical field of transient stability prevention and control aided decision making of a power grid and discloses a transient stability prevention and control aided decision making method based on a security domain. The method comprises the steps that practical dynamic security domain information, power grid operation mode information and control cost information are obtained firstly, then transient stability assessment based on the practical dynamic security domain is performed, control strategy calculation based on transient stability improvement is performed, strategy calculation of node injection power reduction control and node injection power improvement control is performed through alternative iteration, and finally additional control strategy calculation of power grid power balance is performed. Rapid analytical calculation of transient stability control aided decision making is achieved by fully utilizing results of offline and online security and stability assessment, limit calculation and control aided decision making analytical calculation, the accuracy and efficiency of transient stability prevention and control aided decision making are constantly improved, and the method has the important significance on improvement of power grid security and stability operation level and improvement of security and stability control benefits.

The invention relates to a Pin-SVM (Support Vector Machine)-based transient stability evaluation method for a power system. The method comprises the following steps: establishing an original feature set comprising training sample data and test sample data; training a transient stability evaluation model of the power system by the training sample data; carrying out stability evaluation on a power system state simulated by the test sample data by using the transient stability evaluation model of the power system; for the fault type of the actual power system, classifying the faults according to the membership degree of a power system feature subset relative to the stable class and unstable class of the power system, if the power system belongs to the unstable class, then the fault being a serious fault; otherwise, the fault being a nonserious failure; obtaining an evaluation index when the fault screening and stability evaluation are completed. According to the method provided by the invention, the feature set dimension and the redundant information can be reduced, and the feature dimension can be reduced, and the evaluation accuracy is higher. The method can be applied to the online safety and stability evaluation of the regional power system in China, and the safe and stable operation of the complex power system is powerfully ensured.

The invention discloses a transient stability real-time assessment method and device based on a deep belief network. The method comprises the steps that a learning sample set is generated by using a time-domain simulation technology; system measurement is taken as model input, a stable state is taken as a model output, the network parameter of the deep belief network is updated through unsupervised pre-training and supervised precise adjustment, and a transient stability assessment model is formed; the data actually measured by a fault clearing moment system is input into the transient stability assessment model, and the transient stability of the system is predicted. According to the method, the electric power system characteristics can be automatically extracted by using the DBN so as to be used for the transient stability assessment, and the requirements for the calculation speed and accuracy of real-time assessment of the transient stability can be met at the same time, the transient stability real-time assessment can be achieved, the assessment efficiency is improved, the assessment accuracy is improved, and the method is simple and easy to implement.

The invention discloses a transient stability risk assessment method considering the uncertainty of new energy units, which generates an expected fault based on the current operating state of the power grid and performs transient stability assessment, and identifies the key transmission section of transient stability corresponding to the fault; by short-term The output interval probability of each new energy power plant is obtained from the prediction results of wind force and light intensity, and the power interval and probability of key transmission sections are obtained by probabilistic power flow calculation; the output of new energy units is increased and the severity of faults is evaluated, and the operation risk of the section power interval is accumulated as Risk indicator for failure. If the risk index of failure is greater than the threshold value, measures to reduce the output of conventional units should be given priority under the premise of ensuring the output of new energy power plants. If the requirements cannot be met, the risk index is guaranteed to be less than the threshold value by limiting the output of new energy power plants. The method of the invention can comprehensively reflect the operating conditions of the system, discover potential risks and weak points in the system, and exert the operating potential of the power grid.

The invention relates to the technical field of power system transient stability assessment, in particular to a power system transient stability assessment method based on power flow characteristics before and after a fault. The specific steps are as follows: S1, data acquisition: obtaining power required for training and testing a classifier System operation data, use PSAT software to build a New England ten-machine thirty-nine node power system model, the simulation platform is based on MATLAB R2016, the present invention adopts the support vector machine (SVM) classifier by design under the concept of safety domain and stability domain. The purpose of making a judgment on the transient stability of the power system is to reduce the number of missed judgment samples under the concept of stability domain. When only one result of the judgment results is that the system is unstable after being disturbed, then the result of the comprehensive analysis is that the system is unstable, which can be Reducing the number of missed judgment samples has certain reference significance for ensuring the safe and stable operation of the power system.

The present invention relates to a method for quickly assessing the transient stability of a super-large city power grid based on a dynamic security domain. Its technical features include the following steps: Step 1. Determine the system data under the potential operating mode of the system to form a system differential algebraic equation; Step 2. According to the system power flow section under the large-scale operation mode, screen heavy-duty lines and substations, and supplement high-power nodes, solve the pre-fault balance point and form a large-disturbance expected accident set; Step 3. Generate a transient stability evaluation scenario set Post-number the evaluation scenarios and start the dynamic safety domain evaluation; step 4, determine the countermeasures and fault response time for the expected accident, search for the critical equilibrium point of transient stability, and calculate the dynamic safety domain of each transient stability evaluation scenario ; Step 5. Evaluate the system's transient stability of the power grid after the expected accident and calculate the stability margin. The invention can shorten the evaluation time of the transient stability of the system and can provide a stability margin.

The invention relates to a power system transient stability evaluation method based on a deep belief network, which extracts feature quantities after a fault according to the maximum phase angle difference of the bus phase angle of the power system during the swing process, and inputs the features into the deep belief network , the invention can realize the rapid evaluation of the transient stability of the power system.

The invention relates to a transient stability evaluation method of an uncertain power system, which belongs to the field of power system stability. The method of the present invention is: first input the basic structural data of the power system, obtain the electromechanical transient equation describing the generator, and further obtain its state equation in vector form; determine the disturbance quantity λ of the system; establish the method of introducing uncertain variables The uncertain power system transient stability evaluation model uses interval Taylor expansion to calculate the relevant response coefficients, and obtains the upper and lower limits of the state quantity x in the power system transient process. The simulation in the single-machine infinite system shows that the method proposed by the invention can effectively evaluate the transient stability of the uncertain power system.

The invention relates to a power system transient stability determination method based on a support vector machine and belongs to the technical field of power system automatic analysis. The method is characterized by determining an input characteristic set of the SVM (Support Vector Machine) using optimization searching step by step, and further establishing transient stability assessment rules through the SVM. The method comprises a first step of determining an input vector alternative set, an input vector element number, a kernel function of the SVM and a training parameter; a step of generating a training sample and a testing sampling; a step of adding all alternative characteristics into the input characteristic set one by one, training the SVM, and determining a characteristic which enables the SVM classification accuracy to be highest; a step of determining whether the characteristic selection computation is completed or not and output of the input characteristic set; and a final step of training the SVM to obtain the stability rules. According to the invention, the algorithm is easy to implement and the computational complexity is low; the method can be applied to on-line safety and stability assessment of power system at different levels such as regional power systems and provincial power systems in the country; and the system safe and stable operation is effectively ensured under the background that the power grid characteristic is gradually complex.