An investigation on the power output on effect of tower height with same diameter of rotor was conducted in a wind turbine site. As the wind acceleration is varying with height, 3 levels were selected according to the availability of tower. The responses of power output with respect to variation of wind speed are changing for the tower heights of 30, 40, and 50 m. The study showed that the actual ideal power output and measured real power output follow the same trend within range of operating wind speed. The empirical model used for calculation of actual ideal power output was compared with real power output and the overall concepts in power output also had been analysed.

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I. INTRODUCTIONWith the rapid technology advancements in industrial control processes, electric utilities are experiencing more demanding requirements on the power quality from the large industrial power consumers. Such power quality problems have been better appreciated when the price paid due to the economic losses caused by them is large. These concerns are reflected in the newer versions of power quality standards, such as IEEE 1159-1995 [1] and . Trends of deregulation happening in Europe and America exert pressures on the utilities to accommodate such demanding requirements in a competitive electricity market environment.Among the various power quality problems, the voltage sag, usually resulting from the faults on parallel transmission/distribution feeders, is attracting quite a large amount of attention of researchers from both industry and academia [3]- [5]. A definitive solution to this problem at large power levels has been commonly called dynamic voltage restorer (DVR), under the rubric of the custom power concept introduced by EPRI [6]. The main function of DVR is to mitigate the voltage sag, although sometimes, additional functions such as harmonic compensation and reactive power compensation are also integrated to the device. It has also been shown in a previous study that the series compensation device such as the DVR as shown in Fig. 1(a) is preferred over shunt compensation strategy as shown in Fig. 1(b) for stiff systems [7], typical of large industrial load installations. Much of the published literature on DVRs deal with a voltage source converter (VSC) realized using two-level converters, which are well suited for 480-V systems [8], [9]. While in high power applications such as at distribution voltage levels, a multilevel converter is a more attractive solution, whose application in a DVR has not been well addressed. On the other hand, for the control of DVR, the open loop feed-forward technique is found to be a common practice, which generally results in poor damping of the output harmonic filter [10]. In the literatures [1] to [10], the implementation details of DVR using Atmel microcontroller are not available. In this paper, the hardware implementation details using embedded microcontroller are presented. The paper is organized as follows. The power architecture is introduced in Section II followed by simulation results in Section III. The experimental results are given in section IV. II. POWER ARCHITECTUREAlthough various topologies may be used to realize the VSC illustrated in Fig. 1, at higher power levels cascaded H-bridge multilevel power conveners are seen to have advantages in several aspects [11], [12]. First, multilevel converters can realize the higher power and high voltage using semiconductor switches of relative small ratings while avoiding the voltage sharing and current sharing problems associated with series and parallel connection of switches commonly employed in two-level converter realization. Second, multilevel converters can synthesize the output voltage with small...

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