| Abstract |
The paper describes both the overall solution of the new d.c. converter meant for hydrogenerators static excitation systems and the specific supply, synchronizing gate control and protection circuits ensuring its operation within wide variation limits of the mains parameters (voltage-frequency) U= (0.2 ... 1.5) Un, f = (0.8 ... 1.6) fn, characteristic in case of failure (shortcircuits in the mains turbine racing in case of load discharge). The operation of the converter under such circumstances permits to maintain a permanent control of the hydrogenerator excitation, under failure conditions and enables the forcing of the excitation at low voltages due to electrical disturbance in the network, in order to maintain a shortcircuit current apt to trigger protection selectively, on the affected branches only, the rest of the consumers remaining energized. Such performances of the converter ensure an increased operating safety for the static excitation system and, implicitly, economic advantages for the user, limiting economic losses. by maintaining some important industrial objectives in operation. |
