Recent Motor-Generator Sets (Completion of a Large-Capacity Frequency Converter)

摘要

The Motor-Generator set (MG set) has a variety of outstanding features. Therefore, its application range is very wide in the fields of power supply, e.g. testing power supply for the factory test of power transformers such as the temperature-rise test and high frequency induced AC withstand voltage test, for the factory test of direct-on-line start of large induction motors, three-phase or single-phase breaking current supplies for type tests of circuit breakers, and so on. Still more, it is applicable to the single phase power supply for the test running of the Shinkansen (Bullet Train) which requires not only a power supply during running but also power back to the grid through MG set during stopping, or being frequency converters, simulators for thermal power generators, wind power generators and motors to drive various equipment for simulating actual grid, and others. Recently the Company manufactured a large-capacity synchronous frequency converter, consisting of a synchronous motor, a synchronous generator and a starting motor. Its starting method is such that the equipment is started by a directly coupled wound-rotor type starting induction motor (called the pony motor) and then the synchronous motor which is running almost at synchronous speed is put into parallel with the grid by applying the ordinary automatic synchronizing equipment for the synchronous generator. As a result, a small disturbance will be given to the grid during starting of the large synchronous motor. Further, we realized the low noise apparatus for better environmental circumstances and the system without cooling water to make maintenance almost unnecessary. As a result, the overall system resulted in easy operational and maintenance for the customer.