| 摘要 |
PURPOSE: To prevent the heat of a regenerative resistor and at the same time surely supply electric power to a magnetic bearing by supplying electric power to the magnetic bearing from the regenerative electric power of an electric motor when a main electric power source is brought into trouble. CONSTITUTION: AC source power is made into a DC by a rectifier 8, and the DC is made into an AC by an AC converter 4 to supply the AC to the stator 2 of an electric motor. A magnetic bearing 3 is fed from the AC power source through an electric power source circuit 11 and a control circuit 12. When a main power source fails, a switch 15 is closed, a pump 1 is operated as a synchronous generator to supply a direct current to a line 5 and to supply electric power to the electric power source 11 through an auxiliary electric power circuit 14. Therefore, the feeding into the magnetic bearing 3 is ensured. When rotation is lowered and consequently the voltage of the auxiliary electric power source circuit is lowered, an emergency switch 18 is closed to feed the electric power of an emergency battery 13 to the magnetic bearing 3. |
