Abstract: A static excitation system that can eliminate shaft vibrations of a generator and overvoltage when it is underexited is provided. The static excitation system includes an initial excitation equipment; a step-down transformer; a 3-phase diode bridge; a boost chopper provided with a transistor and a resister, and maintaining DC voltage to be constant; a DC chopper provided with a plurality of transistors and diodes, and supplying DC power to a rotor of a generator; a boost controller for controlling the boost chopper; and a DC chopper controller for controlling the DC chopper, wherein, overvoltage applied on the excitation system when underexcited is eliminated owing to the boost chopper preventing any changes at an output terminal of the generator from being transferred to the excitation system, and maintaining the excitation DC voltage to be constant; and also owing to the DC chopper which is capable of 4 quadrant operation, hereby pole slipping of the generator can be prevented.

Abstract: A rotor of a synchronous motor and a method of manufacturing the same. The rotor of the synchronous motor comprises a main core, formed from a plurality of laminated thin iron sheets, the thin iron sheets having a hole at a center for receiving a rotating shaft, and a number of magnet holes and induced conductor holes radially disposed in the thin iron sheets at a predetermined space differently from the hole. A plurality of magnets are inserted into the magnet holes of the main core. Supplementary cores, having a hole and induced conductor holes corresponding to the hole and the induced conductor holes of the main core, are disposed at the ends of the main core wherein the magnet is inserted. An induced conductor formed by ingoting through the induced conductor holes of the main core and the induced conductor holes of the supplementary cores. Consequently, through the induced conductor and the magnet, the efficiency of the motor can be improved.

Abstract: A linear compressor including a casing, a driving unit provided within the casing, a compressing unit driven by the driving unit, compressing refrigerant, and a supporting spring elastically supporting the compressing unit, a projection projecting from on one of the compressing unit and a ceiling part of the casing, and a stopper provided in a remaining one thereof, movably accommodating the projection within a predetermined movable range. With this configuration, the linear compressor is capable of preventing a collision between a compressing unit and an inner face of a casing.

Abstract: The present invention relates to a static excitation system that can eliminate shaft vibrations of a generator and overvoltage when it is underexited. More specifically, the present invention relates to a static excitation system that can eliminate shaft vibrations of a generator and transient phenomena generated in a prior art, so that the present invention can be applied in a field in which an excitation system has a great importance in an isolated system or a weak system.

Abstract: A rotor of a synchronous motor and a method of manufacturing the same. The rotor of the synchronous motor comprises a main core, formed from a plurality of laminated thin iron sheets, the thin iron sheets having a hole at a center for receiving a rotating shaft, and a number of magnet holes and induced conductor holes radially disposed in the thin iron sheets at a predetermined space differently from the hole. A plurality of magnets are inserted into the magnet holes of the main core. Supplementary cores, having a hole and induced conductor holes corresponding to the hole and the induced conductor holes of the main core, are disposed at the ends of the main core wherein the magnet is inserted. An induced conductor formed by ingoting through the induced conductor holes of the main core and the induced conductor holes of the supplementary cores. Consequently, through the induced conductor and the magnet, the efficiency of the motor can be improved.

Abstract: A vibration-actuated pump is connected to a stirling-cycle refrigerator for absorbing the vibration generated when the stirling refrigerator is operated. The absorbed vibration is converted into a driving power for operating a pump to circulate a heat-transferring medium of a cooling circuit and/or a freezing circuit.