UNITROL6000-励磁系统培训.ppt

* * * * * * * * ____________________ UNITROL? 5000 S C Training ___________________ 25. 04. 2003 Rel.: V1 * ? 2005 ABB Ltd 09/09/2005 * The closed loop regulating circuit The closed loop regulating circuit of the synchronous machine can be represented for the electrical variables as shown in the figure. The output voltage UG of the synchronous machine is picked up by the voltage regulator of the excitation system and compared with the setpoint. The output of the excitation system in the form of the excitation current If is the input to the synchronous machine, which closes the regulating circuit. For a synchronous machine coupled to an electrical network, the network simply acts as a disturbance value. Disturbances in the network such as the shutting down of large consumers or short circuits influence the generator voltage in an undesirable way. It is the function of the excitation system to balance out these undesirable changes immediately and to operate the machine stably on the network. * * * * * * * * * * * * * * * * ____________________ UNITROL? 5000 S C Training ___________________ 25. 04. 2003 Rel.: V1 * ____________________ UNITROL? 5000 S C Training ___________________ 25. 04. 2003 Rel.: V1 * ____________________ UNITROL? 5000 S C Training ___________________ 25. 04. 2003 Rel.: V1 * ____________________ UNITROL? 5000 S C Training ___________________ 25. 04. 2003 Rel.: V1 * * * A Static Excitation System for a synchronous machine consists mainly of the following components: Within the power circuit there are: the excitation transformer the thyristor converter, with or without redundancy the field suppression components with: - breaker, crowbar, de-excitation resistor, field flashing and the Regulator, one or two channels, with the main functions of: - voltage regulation with pulse generation, - protection, monitoring and logic control of the complete system * * * * The highest redundancy concept is provided wit