• Proceedings of the KIEE Conference
• /
• 2000.07b
• /
• pp.600-602
• /
• 2000

This paper deals with finite element analysis of 2GVA superconducting generator which has slitted electrothermal shield in d-axis. Open emf voltage is calculated and three phase fault is considered to Predict the generator parameters by F.E.M. Results show that quick response excitation could be applied to superconducting generator with slitted electrothermal shield.

• New & Renewable Energy
• /
• v.10 no.4
• /
• pp.3-8
• /
• 2014

Both of induction generator and synchronous generator is available in the hydroelectric power plant. If the output of the power station is large, the synchronous generator is mainly used but when its output is low, the induction generator is often used. If the output capacity is small, there is a case in which induction motor is used as a generator. Torque at rated operation and start of the induction motor is different depending on the shape of the rotor. Small and medium-sized squirrel-cage induction motor is used primarily double cage rotor or deep bar. In this study, we attempt to interpret characteristics for double cage rotor or deep bar that occur when operating in the induction generator based on the parameters that have been designed and manufactured as an induction motor.

• Journal of Magnetics
• /
• v.17 no.1
• /
• pp.19-26
• /
• 2012

This paper deals with the performance analysis and estimation of the electrical parameters of a permanent magnet synchronous generator (PMSG) for hydrokinetic energy conversion applications using vortex induced vibration (VIV). The analytical solutions for the magnetic fields produced by permanent magnets (PMs) and stator winding currents are obtained using a 2D polar coordinate system and a magnetic vector potential. An analytical expression for the 2D permeance is also derived, which takes into account stator skew effects. Based on these magnetic field solutions and the 2D permeance function, electrical circuit parameters such as the backemf constant and the air-gap inductance are obtained analytically. The performances of the PMSG are investigated using the estimated electrical circuit parameters and an equivalent circuit (EC). All analytical results are validated extensively using 2D finite element (FE) analyses. Experimental measurements for parameters such as the back-emf and inductance are also presented to confirm the analyses.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.20 no.7
• /
• pp.645-649
• /
• 2007

Partial discharge(PD) test for simulated insulation defects of used hydro generator stator winding was conducted to analyze the PD Parameters. Simulated insulation defects are classified by 5 types corona, slot, internal, multi and aging defect. Phase resolved partial discharge, statistical parameter (skewness, kurtosis), PD magnitude as a function of the test voltage(Q-V curve) and PD magnitude change under test voltage for 2 minutes are used as PD parameters. The analysis of PD parameters by 4 types are proved to be useful methods. In particular, PD parameter characteristics of aging defect could help to assess the aging condition of stator winding because aging defect has more weak insulation strength than other insulation defects : PD distribution is wide and flat, PD rises rapidly near $0^{\circ}\;and\;180^{\circ}$ and Q-V curve rises sharply and then gently drops.

• Journal of Institute of Control, Robotics and Systems
• /
• v.4 no.3
• /
• pp.321-328
• /
• 1998

When we control the level of the steam generator in the nuclear power plants, a swell and shrink arises from many disturbances such as feed water rate, feed water temperature, main steam flow rate, and coolant temperature. If we use the conventional type of PI controller in this system, we will not have stability during controlling at lower power, the removal function of disturbances, and a load follow-up control effectively. In this paper, we study the application of a 2-Degree of Freedom(2-DOF) PID controller to the level control of the steam. generator of nuclear power plants through the simulation and the experimental steam generator. We use the parameters $\alpha$, $\beta$, $\gamma$ of the 2-DOF PID controller for the removal of disturbances and the parameters Kp,Ti,Td of the conventional type of PID controller for controlling setpoint. The back-propagation learning algorithm of neural network is used for tuning the 2-DOF PID controller. We can find satisfactory results of the removal of the disturbances and the tracking function in the change of setpoint through the simulation and experimental steam generator.

• Journal of Electrical Engineering and Technology
• /
• v.8 no.6
• /
• pp.1365-1370
• /
• 2013

This paper examines the effects of magnetic induction attenuation on current distribution in the exit regions of the Faraday-type, non-equilibrium plasma Magnetohydrodynamic (MHD) generator by numerical calculation using cesium-seeded helium. Calculations show that reasonable magnetic induction attenuation creates a very uniform current distribution near the exit region of generator channel. Furthermore, it was determined that the current distribution in the middle part of generator is negligible, and the output electrodes can be used without large ballast resistors. In addition, the inside resistance of the exit region and the current concentration at the exit electrode edges, both decrease with the attenuation of magnetic flux density. The author illustrates that the exit electrodes of the diagonal Faraday-type, non-equilibrium plasma MHD generator should be arranged in the attenuation region of the magnetic induction, in order to improve the electrical parameters of the generator.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.13 no.4
• /
• pp.1806-1813
• /
• 2012

This paper proposes a modeling method for hybrid generation system with wind turbine and diesel generator applicable in island area. For modeling objects, squirrel-cage induction generator is considered as wind turbine generator and synchronous generator as diesel generator. Parameters and controllers related to them are established and modeled through analysis of traditional small capacity class. The simulation results for practical size hybrid generation system were suggested.

• Journal of Power System Engineering
• /
• v.11 no.3
• /
• pp.3-8
• /
• 2007

The emergency AC power supply system of the nuclear power plant is designed to supply the power to the nuclear reactor at the emergency operating condition. The safety function of the diesel generator at the nuclear power plant is to supply AC electric power to the plant safety system whenever the preferred AC power supply is unavailable. The reliable operation of onsite emergency diesel generator should be ensured by a conditioning monitoring system designed to maintain and monitor and forecast the reliability level of diesel generator. To do this kind of diesel generator condition monitoring we reviewed several operating factors and history of the wolsong unit 3 diesel generator and selected the proper conditioning monitoring operating factors.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.7 no.3 s.18
• /
• pp.174-183
• /
• 2004

In this paper, the performance improvement and modeling of small onboard generator were described. As the characteristics of the field coil which are a major parameters of generator were improved, the system bandwidth could be increased, therefore the generator could also be satisfied with fast characteristic loads. Established the brief control model of the generator, it could be possible to do the analysis of generator performance, and improve the operational stability of the generator system using the control model.

• Nuclear Engineering and Technology
• /
• v.55 no.1
• /
• pp.109-118
• /
• 2023

In this paper, the evaluation method of fluidelastic instability (FEI) of newly designed steam generator tubing in pressurized water reactor (PWR) nuclear power plants is discussed. To obtain the parameters for prediction of the critical velocity of FEI for steam generator tubes, experimental research is carried out, and the design parameters are determined. Using CFD numerical simulation, the tube array scale of the model experiment is determined, and the experimental device is designed. In this paper, 7 groups of experiments with void fractions of 0% (water), 10%, 20%, 50%, 75%, 85% and 95% were carried out. The critical damping ration, fundamental frequency and critical velocity of FEI of tubes in flowing water were measured. Through calculation, the total mass and instability constant of the immersed tube are obtained. The critical damping ration measured in the experiment mainly included two-phase damping and viscous damping, which changed with the change in void fraction from 1.56% to 4.34%. This value can be used in the steam generator design described in this paper and is conservative. By introducing the multiplier of frequency and square root of total mass per unit length, it is found that the difference between the experimental results and the calculated results is less than 1%, which proves the rationality and feasibility of the calculation method of frequency and total mass per unit length in engineering design. Through calculation, the instability constant is greater than 4 when the void fraction is less than 75%, less than 4 when the void fraction exceeds 75% and only 3.04 when the void fraction is 95%.