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KRALJ, K.
WIND POWER PLANTS MODELS IN PROGRAMMING ENVIRONMENT ANALYSIS
KOMUNALNA ENERGETIKA / POWER ENGINERING, 19
The purpose of this paper is to analyze Simulink`s program models of wind power stations. We propose to examine different types of wind farms, from squirrel cage induction generator, synchronous generator and moreover doubly fed induction generator. Firstly we have studied the parameters of each model and discovered when it can be used. Therefore we have used them for simulation of various operating states. The detailed analysis of DFIG, including phasor type and dynamic model has been conducted, while pointing out their differences.
POLAJŽER, B., SRPAK, D.
Evaluation of Probability-Distribution Models for Wind-Power Forecast Error
KOMUNALNA ENERGETIKA / POWER ENGINERING, 53
This paper discusses different probability-distribution models for wind-power forecast error. Models known from the literature (beta, Weibull, gamma) are discussed along with the models with extended-skew generalized-normal distribution. Furthermore, a versatile model is discussed, which enables analytical calculation of the percentile function; however, it is sensitive to wavelets in the probability distribution. Obtained results show that beta, Weibull and gamma probability distributions do not capture the actual (empirical) one; far more adequate are models with skew generalized-normal probability distribution.
BOGOVIČ, J., MIHALIČ, R.
Flexible Alternating Current Transmission System Devices Compensator for Distribution System
KOMUNALNA ENERGETIKA / POWER ENGINERING, 171
One of the possible solutions for improving voltage conditions in an electric power system (EPS) is applying power electronics based or so called flexible alternating current transmission system (FACTS) devices. However, the appropriate inclusion of a FACTS device into the EPS is not a straightforward procedure. On the contrary, it requires several steps. One of the first steps is the power flow analysis, which requires an appropriate FACTS device modelling.
In the past the models of FACTS devices for Newton-Raphson (NR) power-flow and current-injection calculation methods have been developed. The NR analysis, however, is not always suitable for distribution networks due to convergence problems. This is why new three-phase models of FACTS devices for the forward/backward sweep method are presented in this paper. Their application is demonstrated on an IEEE 34 and 123 bus test systems, in order to clearly present the approach virtues for FACTS modelling in distribution networks with included distributed generation units (DGs).
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