• Journal of Sensor Science and Technology
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• v.21 no.4
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• pp.303-310
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• 2012

We carried out the power performance evaluation for 1.5 MW${\times}$2 by using anemometer installed on WTGS(Wind Turbine Generator System) in the wind farm at Shi-hwa bang-a-mu-ri. In this paper, we compared and analyzed the performance of guaranteed output and measured output of WTGS which includes output curve, output coefficient, AEP(Annual Energy Product) and availability, etc.. The power performance of WTGS was optimized in the low wind speed sections(3 m/s ~ 10 m/s) and the measured output was more produced by AEP 109 % and availability 112 % than the guaranteed output. In addition, we could also cut the high cost of testing WTGS performance by using anemometer as a substitute for weather mast.

• Journal of Industrial Technology
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• v.25 no.B
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• pp.149-157
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• 2005

The power performance monitoring system for a small class of wind turbine is established. The wind turbine power performance characteristics are determined by measured power curve and the estimated annual energy production (AEP). The measured power curve is determined by collecting simultaneous measurements of wind speed and power output at the test site under varying wind conditions. In order to determine the power performance characteristics of the wind turbine accurately, the data are of sufficient quantity and quality shall be corrected according to defined criteria. In this study, the 6kW wind turbine made by Germany Inventus GmbH is examined.

• Journal of Power Electronics
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• v.3 no.2
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• pp.139-144
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• 2003

In this paper, 11 and 13 layered step-down piezoelectric transformers were fabricated and their electrical characteristics have been analyzed for AC-adapter. When the voltage is applied to the driving piezoelectric vibrator polarized in the longitudinal direction, the output voltage is generated at the generating piezoelectric vibrator polarized in the thickness direction due to the piezoelectric effects. From the piezoelectric direct and converse effects, symbolic expressions between the electric inputs and outputs of the step-down piezoelectric transformer are derived with an equivalent circuit model. With those expressions, load and frequency characteristics are discussed through the simulations. Output voltage and current from a 11-layered and a 13-layered piezoelectric transformers were measured under the different load and frequency conditions. First we measured resonant frequency from impedance curve and got equivalent impedance value of the piezoelectric transformer from admittance plot. It was shown from experiments that output voltage increase s and resonant frequency changes according to the various resistor loads. Output current decreases inversely proportional to the change of loads. Moreover, the measured output voltage and current are well matched with the simulated results obtained from the proposed equivalent circuit model. Furthermore, a new step-down piezoelectric transformer has been suggested to Increase the output power based on a simulation result having a driving piezoelectric vibrator polarized thickness direction.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.389-392
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• 2001

In this paper, we have explained electrical characteristics of a step-down Rosen type piezoelectric transformer for AC-adapter. When the electric voltage is applied to the driving piezoelectric vibrator polarized in the longitudinal direction, then output voltage is generated at the generating piezoelectric vibrator polarized in the thickness direction due to the piezoelectric effects. Output voltage and current from a 11-layered and a 13-layered piezoelectric transformer were measured under the various conditions of loads and frequencies. We measured resonant frequency from impedance curve. It was shown from experiments that output voltage has increased and resonant frequency has changed according to various resistor loads. Output current has changed inversely proportional to resistances.

• Proceedings of the KIEE Conference
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• 1998.07d
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• pp.1462-1464
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• 1998

Poly-Si TFT(Thin Film Transistor) is a electronic device that can be applied to the field of large area electronics such as AMLCD. We have fabricated the poly-Si TFT with lateral body terminal that is counter-doped body electrode and investigated the electrical characteristics of it. The lateral body terminal being short with s terminal, we have measured the transfer charac (Vg-ld) and the output characteristic (Vd-ld) fabricated devices. The measured result showe only that leakage current in OFF-state was re and Kink effect in ON-state was suppressed bu that in output characteristic curve the output Id was sustained constantly with the output v Vd in the saturation region.

• Proceedings of the KIPE Conference
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• 2001.10a
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• pp.47-51
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• 2001

In this paper, we have explained electrical characteristics of a step-down Rosen type piezoelectric transformer for AC-adapter. When the electric voltage is applied to the driving piezoelectric vibrator polarized in the longitudinal direction, then output voltage is generated at the generating piezoelectric vibrator polarized in the thickness direction due to the piezoelectric effects. From the piezoelectric direct and converse effects, symbolic expressions between the electric inputs and outputs of the step-down piezoelectric transformer have derived with an equivalent circuit model. With the symbolic expressions, load and frequency characteristics have discussed through simulation. Output voltage and current from a 11-layered and a 13-layered piezoelectric transformers were measured under the various conditions of loads and frequencies. First we measured resonant frequency from impedance curve and got equivalent impedance value of the piezoelectric transformer from admittance plot. It was shown from experiments that output voltage has increased and resonant frequency has changed according to various resistor loads. Output current has decreased inversely proportional to changing of loads. Moreover, the measured values of output voltage and current are well agreed with the simulated values of the proposed equivalent circuit model.

• The Transactions of the Korean Institute of Power Electronics
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• v.25 no.2
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• pp.118-126
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• 2020

A solar array simulator is a special power supply that regulates the output voltage and current to simulate the characteristics of a photovoltaic panel. The operating point of the panel is difficult to control with a single controller because of the non-linearity of the output curve, which is determined by the amount of irradiation, temperature, and panel material. In the conventional method, the output curve is divided into sections through the current and the voltage mode controls. It reduces the overall performance of the system due to the interchanging control mode. By using the single mode controller, the noise interference of the measured value and the stability of the control around the maximum power point were demonstrated. To solve these issues, this study proposes a new unified controller. The stability of the controller was analyzed along with operating principles, and performance improvement was experimentally verified.

• Proceedings of the IEEK Conference
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• 2001.06a
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• pp.169-172
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• 2001

This paper has been studied a calibration techniques for monopole antenna in the frequency range 150 KHz to 30 MHz. The long wavelength associated with the low frequency, methods used to calibrate or characterize antennas at higher frequencies are not applicable. The equivalent capacitance substitution method uses a dummy antenna in place of the actual rod element See figure 1. for guidance in making a dummy antenna. Set up the matching network to be characterized and the measuring equipment as shown in Figure 2. Subtract the measured output of the matching network from the measured output of the signal generator and subtract -6 dB(for the 1 m rod). Measurements made at a sufficient number of frequencies number of frequencies to obtain a smooth curve of antenna factor.(fig 5.)

• Korean Journal of Optics and Photonics
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• v.1 no.2
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• pp.155-161
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• 1990

A Continous wave tunable $CO_2$ laser which is the slow axial flow type was construccted for the optical pumping of methyl alcohol ($CH_3OH$) laser. The reflective grating of 100 grooveslmm and 10.6$\mu\textrm{m}$ blaze wavelength was used to select wavelength. We have investigated continous outpu: power characteristics, and then have compared tuned output power profile with the gain curve of $CO_2$ laser. The optimum condition for maxium power was found at the gas mixing ratio 1 : 3 : 10 for $CO_2: N_2$ and He. under this condition the flow rate, pressure of lasing gas and discharge current are 9.5 llmin. 14 torr, and 55 mA respectively. The maxium output power was 55 Wlm. Output power of single wavelength operation was measured on 60 individual rotation vibration transitions in the P and K branches of the 9.5$\mu\textrm{m}$ band and 10.4$\mu\textrm{m}$ band in $CO_2$. The output power profile obtained from each band is well consistent with the gain curve of $CO_2$ laser and maxium tuned output power was 20 watt.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.2
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• pp.327-331
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• 2005

In this paper, Another way to measure the visibility of image is presented, and this way is different with existing way which is measured by filtering such as High pass, Low pass. Dynamic range, Gray level and Condition Curve Graph is used among much information of histogram, and the output is limited by log scale. As a result, I can confirm that the output is reasonable. With this output, I present that the possibility of another way to measure the visibility of image is existing.