• The KSFM Journal of Fluid Machinery
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• v.12 no.6
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• pp.26-32
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• 2009

We have constructed loading apparatuses to electrical motor with a powder brake and a oil pump for load test of a several ten kilowatt-motor and performed load test with two motors. On operating the loading apparatus with a oil pump, temperature of the oil may excessively increase and fail to operate due to dynamic energy loss of equipment in oil loop. In order to control the oil temperature, factors of the energy loss were analyzed and the quantitative loss was calculated. Load tests of motors with two loading apparatuses constructed were successfully performed and strengths of each apparatus come out on operating.

• Proceedings of the KSME Conference
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• 2001.06d
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• pp.260-265
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• 2001

This paper describes total flow control of an ice slurry system for pump energy saving. Similar turbo machinery has a characteristic that input power ratio is proportional to the three time of revolution speed ratio. To reduce the energy cost of brine pump in ice slurry storage systems, inverter is adapted instead of 3-way valve to control the speed of brine pump motor. One type of cooling load profile was used as driving load of the system, generated by a boiler and warm water storage tank. As results of the laboratory test, energy consumption and cost of the pump were reduced by 11.4%.

• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.4
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• pp.1062-1070
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• 1995

The study deals with controlling the velocity of hydraulic motor with PI controller through the control of displacement pump which has higher efficiency than valve-controlled system. This was done as follows. First, we modified original displacement pump and designed this electrohydraulic puma system. Second, after experimenting static and dynamic characteristics, we identified system parameter of approximated model. Lastly, to control the velocity of hydraulic motor we controlled the angle of the swash plate of displacement pump. Test carried out in the laboratory shows that transient and steady state response could be improved by PI controller reducing power loss.

• Proceedings of the KIEE Conference
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• 2004.10a
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• pp.113-115
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• 2004

This paper presents a design and characteristics analysis of an SRM drive for a hydraulic pump application. A hydraulic pump is used AC Induction motor in conventional applications. The suggested drive system supplies required pressure on-line for energy saving, while conventional one holds the pressure during stand by period. The prototype motor is designed and tested through simulation and experiments.

• Transactions of The Korea Fluid Power Systems Society
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• v.4 no.1
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• pp.7-12
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• 2007

It is strongly requested to reduce fuel consumption because of high oil price and exhaust gases of road vehicles for environmental preservation. To solve these problems, several types of hybrid vehicles have been developed. Among them, flywheel hybrid vehicle using variable displacement pump/motor was already proposed as one of the feasible hybrid systems in place of hybrid vehicle by the conventional storage battery. The proposed flywheel hybrid vehicle is to keep constant pressure of high pressure line by the control of swash plate angle of flywheel pump/motor as pressure compensator. The efficiency of the overall system depends severely on the efficiency of hydraulic pump/motor in the energy saving hydraulic control system by simulation. According to the control methods of swash plate angle of piston pump/motor, there remain several problems to be solved. In this paper, experimental setup for energy saving is fabricated and the efficiency of energy saving is investigated by experiments with respect to various experimental conditions.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.1081-1086
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• 2007

It is strongly requested to reduce fuel consumption because of high oil price and exhaust gases of road vehicles for environmental preservation. To solve these problems, several types of hybrid vehicles have been developed. Among them, flywheel hybrid vehicle using variable displacement pump/motor was already proposed as one of the feasible hybrid systems in place of hybrid vehicle by the conventional storage battery. The proposed flywheel hybrid vehicle is to keep constant pressure of high pressure line by the control of swash plate angle of flywheel pump/motor as pressure compensator. The efficiency of the overall system depends severely on the efficiency of hydraulic pump/motor in the energy saving hydraulic control system by simulation. According to the control methods of swash plate angle of piston pump/motor, there remain several problems to be solved. In this paper, experimental setup for energy saving is fabricated and the efficiency of energy saving is investigated by experiments with respect to various experimental conditions.

• Journal of the Korean Society for Precision Engineering
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• v.24 no.5
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• pp.68-76
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• 2007

It is strongly requested to reduce fuel consumption because of high oil price and exhaust gases of road vehicles for environmental preservation. To solve these problems, several types of hybrid vehicles have been developed. Among them, flywheel hybrid vehicle using variable displacement pump/motor was already proposed as one of the feasible hybrid systems in place of hybrid vehicle by the conventional storage battery. The proposed flywheel hybrid vehicle is to keep constant pressure of high pressure line by the control of swash plate angle of flywheel pump/motor as pressure compensator. The efficiency of the overall system depends severely on the efficiency of hydraulic pump/motor in the energy saving hydraulic control system by simulation. According to the control methods of swash plate angle of piston pump/motor, there remain several problems to be solved. In this paper, experimental setup for energy saving is fabricated and the efficiency of energy saving is investigated by experiments with respect to various experimental conditions.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.6
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• pp.1249-1256
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• 2018

Recently the research on artificial intelligence is actively processing in the fields of diagnosis and prediction. In this paper, we acquire the data of electrical current, revolution per minute (RPM) and vibration that is occurred in the motor and pump where hey are installed in the industrial fields. We train the acquired data by using the k-nearest neighbors. Also, we propose the status diagnosis methods that judges normal and abnormal status of motor and pump by using the trained data. As a proposed result, we confirm that normal status and abnormal status are well judged.

• Nuclear Engineering and Technology
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• v.54 no.7
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• pp.2540-2549
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• 2022

For a pressurized water reactor power plant, the reactor coolant pump (RCP) is a kernel component. And for a canned motor RCP, the rotor system's properties determines its safety. The liquid coolant inside the canned motor RCP fills clearance between the metal shields of rotor and stator, forming a lengthy clearance flow. The influence of inlet preswirl on rotordynamic coefficients of clearance flow in canned motor RCP and their effects on the rotordynamic characteristics of the pump are numerically and experimentally investigated in this work. A quasi-steady state computational fluid dynamics (CFD) method has been used to investigate the influence of inlet preswirl. A vertical experiment rig has also been established for this purpose. Rotordynamic coefficients on different inlet preswirl ratios (IR) are obtained through CFD and experiment. Results show that the cross-coupled stiffness of the clearance flow would change significantly with inlet preswirl, but other rotordynamic coefficients would not change significantly with inlet preswirl. For the case of clearance flow between the stator and rotor cans, influence of inlet preswirl is not so significant as the IR is not large enough.

• The Transactions of the Korean Institute of Power Electronics
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• v.18 no.6
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• pp.540-546
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• 2013

The induction motor is used for driving the special equipments such as warship and submarine pump due to robust structure and simple maintenance. Domestic and foreign warships use a wide range of voltages and the DC voltage sources mainly from battery. In the low voltage level, the ${\Delta}$-connection operation of induction motor can be used for the maximum power. However, the temperature of the inverter increases because of the high input current. On the other hand, Y-connection operation of the induction motor does not cause a problem of temperature because of the low input current compared to the ${\Delta}$-connection. But the lack of the supply voltage can not be avoided. Therefore, this paper suggests the algorithm of the optimum field weakening control to extend the operating range of the induction motor with maximum power in a limited thermal and DC voltage condition.