電力系統における可変速揚水発電電動機の系統安定度向上に関する研究

抄録

To adjust a frequency during midnight or while an electric power system is carrying a light load, an AC excitation synchronous machine is recently being used in place of the conventional fixed-speed synchronous machine as the generator/motor at a pumped-storage power station. The use of this synchronous machine makes it possible to adjust the rotor speed and to use its inertial energy. We have prepared this paper to show how we can improve the power system stability by using the highly responsive control of the terminal voltage and the active electric power control through the AC excitation control of this adjustable-speed machine. The abstract of this paper can be summarized as follows:
(1) We can enlarge the zone of stable operation by performing terminal voltage and active power control along with current control for the AC excitation of an adjustable-speed machine.
(2) As the stability analysis model of an adjustable-speed machine, we can use an AC excitation woundrotor induction motor. We were able to verify the effectiveness by comparing simulations with the results of the transmission system simulator.
(3) We can substantially improve the system stability by absorbing the power swing of the fixed-speed machine with the adjustable-speed machine, thereby decreasing it.
(4) The effect produced by the adjustable-speed machine for the improvement of the power system stability is more prominent in the transient stability than in the dynamic stability and also more so in the pumping operation than in the generating operation.