• The Transactions of the Korean Institute of Power Electronics
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• v.14 no.1
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• pp.38-45
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• 2009

To get the constant output, synchronous generator field excitation is controlled by AVR(Automatic Voltage Regulator). Most of ships generator AVR uses the thyristor phase controlled rectifier. However this rectifier is difficult to realize that the fast control system because its control period is slower than MOSFET and IGBT type converter. Therefore, this paper deals with PMG(Permanent Magnet Generator) type digital AVR using MOSFET switch for ships synchronous generator. The composition of this digital AVR is very simple, the generator is under the short circuit accident, the output voltage becomes zero state and AVR can not operate. Thus generator is required to add CBC(Current Boosting Circuit) in an excitation circuit to flow output current. The performance of the proposed system is evaluated on a 10[kVA] experimental prototype circuit in place of real ships generator.

• The Transactions of the Korean Institute of Power Electronics
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• v.11 no.5
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• pp.463-470
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• 2006

This paper deals with a new 3-phase power quality disturbance generator. The proposed generator can provide phase jump as well as voltage sag, swell, outage, unbalance, and over and under voltage. The operating principle of the generator is described in each mode of disturbance. The magnitude of the phase jump is analysed and it is found that the magnitude is the function of the turn-ratios of the transformers consisting the generator. The scheme has simple structure compared with the conventional one, and the major components of the proposed scheme are SCR thyristor and transformer, which guarantees high reliability and cost-effective implementation of the generator. Furthermore, high efficiency can be obtained because there is no PWM switching of the semiconductor devices, and it is easy to control the system. Simulations are carried out to confirm the operation in each disturbance mode, and experiments has been done with 5kVA power rating. The usefulness of the proposed scheme is verified through simulation and experimental results. It is expected that the scheme can be applied to the performance test of the custom power devices such as UPS, DVR, DSTATCOM, and SSTS with cost-effective system.