Showing posts with label Contingency Evaluation. Show all posts
Showing posts with label Contingency Evaluation. Show all posts

Thursday, 1 December 2011

Transient Stability Analysis


The recovery of a power system subjected to a severe large disturbance is of interest to system planners and operators. Typically the system must be designed and operated in such a way that a specified number of credible contingencies do not result in failure of quality and continuity of power supply to the loads. This calls for accurate calculation of the system dynamic behavior, which includes the elector-mechanical, dynamic characteristics of the rotating machines, generator controls, static var compensator, loads, protective systems and other controls. Transient stability analysis can be used for dynamic analysis over time periods from few seconds to few minutes depending on the time constants of the dynamic phenomenon modeled.



The dynamic performance of the system with respect to the disturbance listed below, but not limited to, shall be studied for the following cases:
  • 3 phase  fault 
  • Unbalanced fault 
  • Fault clearance 
  • Loss of transformers 
  • Loss of lines
  • Loss of loads
  • Loss of generators
  • Load shedding
  • Any other relevant contingency
Report and Recommendations from Transient Stability studies
  1. Plots of dynamic response of generator rotor angles, frequency, power outputs, voltages, excitation system outputs and governor prime mover outputs
  2. Plots of Lines, transformer flows, bus voltages, bus frequencies
  3. Plots of the system variables that are of interest from protection point of view like frequencies, fault current seen from over-current relays,etc
  4. Recommendation related to protection and control, operating strategy, Load shedding schemes,  control settings of equipments ( for example: power system stabilizer, relay settings etc), based on various study cases considered
Read more : http://kalkitech.com/offerings/services-power_system_consulting_services-about_power_system_analysis/

Contingency Studies


Contingency Studies


Maintaining power system security is one of the most important requirements for any utility and this includes planning for various contingency situations like outage of transmission lines; loss/recovery of generators and loads; changing/setting of switched shunts; injection groups; as well as opening/closing of buses and equipments. Contingency evaluation is carried out by using static as well as dynamic analytical tools such as load flow analysis and transient stability analysis. Real time control and monitoring solutions in energy control centers or energy management systems or load dispatch centers usually use an algorithm called contingency ranking algorithm to shortlist credible contingencies for real time evaluation and control of power systems. Often contingency ranking algorithm will use some approximate and fast load flow type algorithms from a list of contingencies and rank them in the decreasing order of severity. This ordered or ranked list will normally be considered for a detailed contingency evaluation to assess system security. Often contingency ranking algorithm will use some approximate and fast load flow type algorithms from a list of contingencies and rank them in the decreasing order of severity. This ordered or ranked list will be considered for a detailed contingency evaluation to assess system security.

Read more : http://kalkitech.com/offerings/services-power_system_consulting_services-about_power_system_analysis/