Before revision: Large brushed machines which are run with DC to the stator windings at synchronous speed are the most common generator in power plants, because they also supply reactive power to the grid, because they can be started by the turbine and because the machine in this system can generate power at a constant speed without a controller.
After revision: Large brushed machines which are run with DC to the stator windings at synchronous speed are the most common generator in power plants, bec00020002 ause they also supply reactive power to the grid, because they can be started by the turbine and because the machine in this system can generate power at a constant speed without a controller.