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Author: AdminEMTP-RV
Type: Model
Downloaded: 375 times
Date: 2012-06-18

Ferro_hyst_Zno

Description:
Simple ferroresonance case. In this case the switching of a part of the network comprised of a cable connected to a no-load transformer is carried out. A pole of the breaker fails to open and an impor... see moretant and stable ferroresonance phenomena appears.
The ferroresonance problem, whether in a general circuit or in a power-system circuit, is usually tackled in one of two ways : circuit configuration (i.e series and/or parallel) or nonlinearities (i.e saturation and hysteresis of transformers). A fundamental factor to the occurence of ferroresonance is the nonlinear magnetizing characteristic of the transformer and the capacitive coupling.
In this case a 250 kVA, 20/0.4 kV transformer is used. This transformer is represented by the hysteresis transformer model. The hysteresis element has been used as the magnetization branch of the one-phase transformer model. A 200 m cable is used for the study. This cable is modelled by a PI-section. The short circuit power of the source is about 150 MVA.
In order to reduce overvoltages caused by ferroresonance, surge arresters are installed. Two questions have emerged : will the arresters mitigate ferroresonance, and will they fail during ferroresonance ? Simulations in different transient regimes can be carried out in order to determine the maximal current, overvoltages (voltage at the end of the cable for instance), energy absorbed by the arresters

Tag(s): Protection

Author: AdminEMTP-RV
Type: Model
Downloaded: 300 times
Date: 2012-06-18

Comp_bctran_3Wind

Description:
A good case of comparison between BCTRAN and the regular encapsulated model available in the transformers library during transient state.

Tag(s): Transformers

Author: AdminEMTP-RV
Type:
Downloaded: 213 times
Date: 2012-06-18

Non_Linear_Benchmark

Description:
Benchmark case for testing the nonlinear solution method of transients simulation packages.

This case shows the superior capability of EMTP-RV to handle simultaneous solutions of three very... see more nonlinear elements: Circuit-breaker arc , Hysteretic characteristic of transformers and Zinc-Oxide arresters.

Tag(s): Example