Transients Stability Analysis
We have an exclusive experience to carry-outfollowing electromagnetic transient study related with the EHV AIS and GIS substation using EMTP software program.
Electro Mechanical Transients Stability :
The study of power system stability involves the analysis of the behavior of power systems under conditions before and after sudden changes in load or generation, during faults and outages. The robustness of a system is defined by the ability of the system to maintain stable operation under normal and perturbed conditions. It is therefore necessary to design and operate a power system so that transient events (i.e. probable contingencies), can be withstood without the loss of load or loss of synchronism in the power system.
Transients in electrical power systems can be classified according to three possible time-frames:
• short-term, or electromagnetic transients;
• mid-term, or electromechanical transients;
• long-term transients.
We perform electromechanical transients stability study using ETAP software and electromagnetic transientsstudy by EMTP software.
Electro Magnetic Transient Analysis :
EMTP is used world-wide for network transient analysis.
The typical EMTP studies,we are performing are:
- Insulation coordination study
Insulation Coordination is the process of determining the proper insulation levels of various components in a power system as well as their arrangements. It is the selection of an insulation structure that will withstand voltage stresses to which the system or equipment will be subjected to, together with the proper surge arrester. The process is determined from the known characteristics of voltage surges and the characteristics of surge arresters.
- Generator transformer Inrush current study
In large transformer, Inrush magnetizing current lasting up to several tens second, the peak value of which are several thousand amperes in maximum, are observed.
A complete study of the Generatortransformer and surrounding network is required to suggest proper protection and operation of the associated power system.
- Closing and reclosing operation on transmission linesand Long cable charging study
Restrikes in line charging current breakings cause high overvoltage in the systems. System design permitting the overvoltage corresponds to over insulation, i.e. expensive construction.
In actual transmission lines, very complicated factors such as capacitive and inductive couplings, skin effects, frequency dependent parameters, etc. exist. So, for detailed survey of the switching's, digital calculations are recommended.