• Proceedings of the KIEE Conference
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• 2005.07b
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• pp.1500-1502
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• 2005

In this paper, the electrical characteristics of the non-contact transformer is presented using conventional coupled inductor theory. Each non-contact transformer is analyzed through simulation and measurement. In high power applications, non-contact transformer is so bulky and heavy that it should be split by some light transformers. So non-contact transformer needs several small transformer modules which are connected series or parallel to transfer the primary power to the secondary one. This paper shows analytic result of the each non-contact transformer module and comparison result between series-connection and parallel-connection of the non-contact transformer. The results are verified on the simulation based on the theoretical analysis and the 30kW experimental prototype.

• Journal of Power Electronics
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• v.4 no.1
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• pp.12-17
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• 2004

In this paper, a practical implementation to reduce leakage flux of a high-frequency inverter based non-contact type power transformer composed of EE-shape ferrite cores is presented for key technology of the next generation medical use X-ray CT scanner system. Design consideration for the unique structure of the non-contact power transformer with 900mm in diameter is also introduced. The complete non-contact transformer is actually arranged by several blocks of the magnetic circuit assembled by using 10 small EE shape cores with 120mm in length. It is experimentally and analytically discussed from a reduced leakage flux viewpoint related to its inductively coupling coefficient. A practical method to lower the leakage flux is described based on effective Copper-Sheet- Treatment placed on EE shape ferrite cores of magnetic circuit.

• Proceedings of the Korea Society of Information Technology Applications Conference
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• 2005.11a
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• pp.233-235
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• 2005

Non-contact power supply (NCPS), as a clean and safe energy supply concept has been applying wildly. Comparing with the conventional transformer the non-contact transformer has a large air gap between the long primary winding and the secondary winding. Due to it, the non-contact transformer has increased leakage inductance and reduced magnetizing inductance. So the high frequency series resonant converter has been widly used on the non-contact power supply system for transferring the primary power to the secondary one, from what a high influence voltage can be gained on the secondry coil even though the large air gap exists. However, it still has the disadvantages of the load sensitive voltage gain characteristics when load is changing. In this paper, we propose a fuzzy logic controller to adjust the frequency of the inverter to track the resonat which is changing when the load is change.

• Proceedings of the KIPE Conference
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• 2005.07a
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• pp.511-513
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• 2005

In this paper, the electrical characteristics of the non-contact transformer is presented using conventional coupled inductor theory. In high power applications, the non-contact transformer is so bulky and heavy that it poses some maintenance problems. Therefore it should be divided into some light transformer modules. This paper shows the analytic method of how to measure the parameters of the multiple connected non-contact transformer The analytical results are verified through measurement.

• Proceedings of the KIPE Conference
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• 2000.07a
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• pp.258-261
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• 2000

A non-contact battery charger which transfers energy using magnetic field has a difficulty with a feed-back control due to the interaction between the power and signal processing This paper proposes an effective method which uses auxiliary windings of transformer as signal path and copes with cross-talk using the MOSFET ringing phenomenon and ceramic filter. The power stage is half-bridge series resonant converter. Design procedure and experimental verification are presented.

• Proceedings of the KIPE Conference
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• 1998.10a
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• pp.447-451
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• 1998

This paper conducts a study on a non-contact power delivering system using high-frequency inverter with the purpose of discussing the non-contact electric power transmission characteristics through circuit analysis, magnetic analysis and feasible experiments. In this power delivering scheme, various properties pertaining to the non-contact transformer of the power system such as the design, the core depth, core material, primary side frequency etc. are considered with a view of improving the non-contact power dilivery to the secondary.

• The Transactions of the Korean Institute of Power Electronics
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• v.9 no.5
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• pp.405-412
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• 2004

In this paper, Non-contact power supply(NCPS) with the long primary cable longer than 20m and the large air-gap between the primary and secondary of Non-Contacting Transformer(NCT) is presented. The NCT has a large leakage inductance bigger than its magnetizing inductance because it has low coupling, and it is not efficient for NCPS to transfer the primary energy to the secondary one. In order to improve this problem, the voltage-gain characteristics of the series resonant converter, the parallel resonant converter, and the series-parallel resonant converter are analyzed respectively. In addition, the experimental results of 10kW prototype the series-parallel resonant converter is presented.

• Proceedings of the KIEE Conference
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• summer
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• pp.1166-1168
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• 2004

The high frequency series resonant converter has been widely used for the non-contact power supply system with the large air gap and the increased leakage inductance of the non-contact transformer. However. the high frequency series resonant converter has the disadvantages of high voltage gain characteristics in the overall load range due to the large air gap and the circulating magnetizing current. In this paper, unit voltage gain is revealed in the proposed three-level series-parallel resonant converter. The results are verified on the simulation results and the 5kW experimental prototype.

• Proceedings of the KIPE Conference
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• 2008.06a
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• pp.574-576
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• 2008

Now there are two types Non-contact compensation AC automatic voltage regulator (A.V.R). One is transformer compensation regulator, whose principle is the combination of multiple compensation transformers, do the compensation by turning on and off the connections of the transformer through the multi-full bridge circuit. This method removed the mechanical drive and contacts, which increases the life and the dynamic performance of the A.V.R. However, the compensation is multilevel, and it needs many compensation transformers and switches, the circuit is complex, the compensation precision is low. Another type is PWM switch AC regulator, whose principle is getting the AC voltage from the input, then induce the AC compensation voltage through commutating and high frequency PWM transforming, and phase tracking. Here the compensation is step-less, the compensation precision is high, and the response is fast. But the circuit is complex, and it needs an inverse compensation transformer, which is difficult to realize high-power applications. In this paper, it shows an Automatic Voltage Regulator which use high frequency PWM inverter do compensation. This A.V.R has the function as the custom-power, which make the performance of the power supply in a high level.

• Journal of IKEEE
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• v.28 no.2
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• pp.131-135
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• 2024

In this study, the sensor such as current transformer type was developed for measuring non-contact partial discharge in power electrical facilities, and the results of the characteristic evaluation were discussed. The frequency response characteristics of the HFCT sensor were shown to be measurable from 20 [kHz] to 20 [MHz]. The average sensitivity for the positive direction was 0.308 [mV/pC], and the negative direction was 0.459 [mV/pC]. Which showed that the sensitivity for the negative direction was better than that for the positive direction. The developed HFCT sensor is possible to measure very small partial discharge pulse signals and can be measured various types of partial discharge that may occur at power electrical facilities.