Computer aided instruction of rotating electric machines viaanimated graphics

A menu-driven interactive graphics software package has been developed for use as an instructional aid for the electric machines course in the electrical engineering curriculum. The main purpose of this tool is to give the students a clearer understanding of the basics of the operation of rotating electric machines. The animation program was developed for displaying live and rotating diagrams depicting different modes of operation of synchronous generators. Different parts are identified with different colors. The interaction of the magnetic poles on the stator and on the rotor, and the relative spatial positions and time variations of the magnetic and electric quantities are demonstrated through moving images. The software features are described     

Distribution System Protection with Decentralized Generation Introduced into the System

Cogeneration from renewable energy sources has been universally proposed as a partial alternative to the solution of our nation's energy problems. New technical, safety, and operational problems are introduced when this generation is placed into a distribution grid. Addressed is the problem of distribution system protection with the introduction of cogeneration sources and the changes and modifications which may be required in the application of present-day protection devices. A sample system is considered, and system protection and coordination with and without cogeneration has been calculated through a digital fault and system protection coordination program. The results indicate through the study of several systems that additional coordination and protection considerations will be required when sizable cogeneration sources are introduced to maintain a high degree of reliability and service continuity.     

Convertible static compensator performance studies on the NY state transmission system

New York Power Authority is installing a new flexible AC transmission system (FACTS) controller, known as the convertible static compensator (CSC), at Marcy 345 kV substation. Two 100 MVA converters are installed. Through one 200 MVA shunt and two 100 MVA series transformers, the converters may be connected to each other and to the system in 11 different configurations. This arrangement of the converters allows STATCOM, SSSC, UPFC, or IPFC deployment at the bus and two of the lines exiting the substation, namely, Marcy-Coopers Corners and Marcy-New Scotland 345 kV lines. Voltage, small signal, and transient stability simulations are conducted using the developed models of these configurations within the user-defined capability of the EPRI's power system analysis package. The focus of the studies is on finding out which configuration of the CSC provides the highest performance improvement from all stability points of view. Modulation controls are designed to improve inter-area oscillation damping. In general, all CSC configurations improve voltage, small signal, and transient stability margins of the system. The performance of the individual devices resulting from CSC configurations and their capabilities in the studied cases is presented. It is shown that the CSC in conjunction with three fixed capacitor banks at three other substations can increase the system power transfer limit by up to 310 MW.     

Fast Thermal Generation Rescheduling

A new dynamic programming algorithm for fast rescheduling thermal generation is presented. The savings in computational times are brought about by the introduction of two new techniques: the variable truncation dynamic programming and the limitation of the solution space to be searched. Several examples on a 20 machine system are used to illustrate the application of the algorithm and to show that optimal solutions are obtained at significantly reduced computational times.     

Thyristor controlled series compensation application study-controlinteraction considerations

A study of the potential for control interaction between a proposed thyristor controlled series compensation (TCSC) and an existing static VAr compensator (SVC) is presented. The results indicate that a control interaction exists between the voltage-input power swing damping control (PSDC) of the TCSC, the series compensated AC system resonances, and the SVC controls. The addition of recommended filtering and synthesized angle-input PSDC showed improved performance     

A governor/turbine model for a twin-shaft combustion turbine

A twin shaft gas turbine unit was tested for the governor response to disturbances. A computer simulation model is presented as well as the test data which was used to derive values for the model parameters     

Sensitivity Methods in the Dispatch and Siting of FACTS Controllers

Flexible AC transmission systems (FACTS) play an important role in improving the transfer capability and stability of a power system. In the application of voltage-sourced converter (VSC)-based FACTS controllers, it is important to study how a VSC impacts the flows in a power system. In this paper, we investigate this flow control problem using two sensitivity approaches, one using an injected voltage source formulation and the other an equivalent impedance formulation. The applications of sensitivity analysis for line active power redispatch and for new series VSC siting in a 1673-bus system are presented.     

Field tests to validate hydro turbine-governor model structure andparameters

A test procedure was developed to obtain accurate governor models for hydroelectric stations owned by the New York Power Authority to improve the accuracy of stability simulations of the New York State system. Tests were performed on units at three stations and values for parameters of previously available model structures were derived from the information obtained during these tests. However, it was found that the model structures were not adequate to represent the entire range of operating conditions. Additional examination of test measurements and model structures indicated that the model structure needed to be refined. This paper reports on the refinements made to the hydro turbine-governor models which enabled reproduction of the physical system responses. Simulation results indicate that the refined models with the corresponding identified parameters produce responses which closely fit those recorded from the tests performed on three hydro units