scholarly journals STUDY OF TRANSIENT AND STATIONARY OPERATION MODES OF SYNCHRONOUS SYSTEM CONSISTING IN TWO MACHINES

Author(s):  
V. S. Safaryan

The solution of the problem of reliable functioning of an electric power system (EPS) in steady-state and transient regimes, prevention of EPS transition into asynchronous regime, maintenance and restoration of stability of post-emergency processes is based on formation and realization of mathematical models of an EPS processes. During the functioning of electric power system in asynchronous regime, besides the main frequencies, the currents and voltages include harmonic components, the frequencies of which are multiple of the difference of main frequencies. At the two-frequency asynchronous regime the electric power system is being made equivalent in a form of a two-machine system, functioning for a generalized load. In the article mathematical models of transient process of a two-machine system in natural form and in d–q coordinate system are presented. The mathematical model of two-machine system is considered in case of two windings of excitement at the rotors. Also, in the article varieties of mathematical models of EPS transient regimes (trivial, simple, complete) are presented. Transient process of a synchronous two-machine system is described by the complete model. The quality of transient processes of a synchronous machine depends on the number of rotor excitation windings. When there are two excitation windings on the rotor (dual system of excitation), the mathematical model of electromagnetic transient processes of a synchronous machine is represented in a complex form, i.e. in coordinate system d, q, the current of rotor being represented by a generalized vector. In asynchronous operation of a synchronous two-machine system with two excitation windings on the rotor the current and voltage systems include only harmonics of two frequencies. The mathematical model of synchronous steady-state process of a two-machine system is also provided, and the steady-state regimes with different structures of initial information are considered.

2018 ◽  
Vol 58 ◽  
pp. 01005
Author(s):  
Magomed Gadzhiev ◽  
Eugenia Gulevich ◽  
Vyacheslav Korobka ◽  
Vladimir Ryabchenko ◽  
Yuriy Sharov

A solution is presented for the problem of placing phasor measurement unit to identify the mathematical model of the electric power system in the state space. The criterion for complete observability of the Kalman dynamic system is taken as a basis. As a method of solution, we use the canonical genetic algorithm. The complete observability of the power system is ensured by the application of the observability rule in the form of a recursive test of observability. The proposed approach is demonstrated by the arrangement of synchronized vector meters in the Kaliningrad region power system.


2019 ◽  
Vol 24 ◽  
pp. 02012
Author(s):  
Yury Shornikov ◽  
Evgeny Popov

Transients in electric power systems are of great interest to power engineers when designing a new or maintaining an existing system. The paper deals with using hybrid system theory for modeling and simulation of an electric power system with controllers. The presented technique is rather convenient and recommended as mathematical models of transients in electric power systems with controllers in general contain both continuous and discrete components. The modeling and simulation were carried out in the modeling and simulation environment ISMA, which is briefly presented in the paper.


2020 ◽  
Vol 11 (11) ◽  
pp. 28-37
Author(s):  
Aleksey A. SUVOROV ◽  
◽  
Alexander S. GUSEV ◽  
Mikhail V. ANDREEV ◽  
Alisher B. ASKAROV ◽  
...  

The transient stability is the main condition for reliability and survivability operation of electric power system. The transient stability analysis is an extremely complex problem. It uses the results of numerical integration of differential equations that form a mathematical model of the power system. However, the mathematical model of a large-scale power system contains a rigid nonlinear system of extremely high-order differential equations. Such system cannot be solved analytically. The simplifications and limitations are used for improving the conditionality of the power system mathematical model in time-domain simulation. It decreases the reliability and accuracy of the simulation results. In this regard, it becomes necessary to validate them. The most reliable way of validation is to compare simulation results with field data. However, it is not always possible to receive the necessary amount of field data due to many power system states and a large amount of disturbances leading to instability. The paper proposes an alternative approach for validation: using an adequate model standard instead of field data. The prototype of Hybrid Real Time Power System Simulator having the necessary properties and capabilities has been used as the reference model. The appropriate sequence of actions has been developed for validation. The adequacy of proposed approach is illustrated by the fragments of the experimental studies


Sign in / Sign up

Export Citation Format

Share Document