Reliability Analysis Functions

Network reliability assessment is used to calculate expected interruption frequencies and annual interruption costs. Reliability analysis is an automation and probabilistic extension of contingency evaluation. The relevance of each outage is considered using statistical data about the expected frequency and duration of outages, taking into account the protection systems and the network operator’s actions to re-supply interrupted customers. This optimal power restoration process can also be analysed and carried out for individual contingencies.
Reliability assessment involves determining, generally using statistical methods, the total electric interruptions for loads within a power system during an operating period. The interruptions and their effects are described by several indices, which are calculated in the simulation. Together with the reliability analysis, an optimal way of placing remote controlled switches (RCS) can be determined, in order to resupply as much demand as possible in the shortest time, with a given number of RCS.
The package also includes Generation Adequacy Analysis, where the system supply capabilities are analysed with the help of stochastic methods.

Failure models

  • Line/cable, transformer, distribution transformer, busbar and circuit breaker failures
  • Generator failures with stochastic multi-state model
  • n-1, n-2 and common mode failures (n-k)
  • Double earth faults
  • Independent second failures
  • Protection/circuit breaker failures
  • Protection over-function

Optimal Power Restoration

  • Failure effect analysis (FEA)
    • Automatic protection-based fault clearing
    • Intelligent high-end system restoration with potential network ­reconfiguration and load-shedding
    • Support of branch and boundary flow limits, absolute ­voltage and voltage drop/rise constraints
    • Sectionalising (remote controlled switches, short-circuit ­indicators, manual restoration)
    • Substation automation with switching rules
  • Animated tracing of individual cases
  • Detailed reports for restoration action plans

Reliability Assessment

  • Fast state enumeration for balanced/unbalanced systems, including optimal power restoration techniques
  • Calculation of all common reliability indices (IEEE 1366)
  • Contribution of components to reliability indices
  • Support of load variation, including load distribution curves
  • Support of generation dispatch profiles
  • Consideration of maintenance schedules
  • Support of various tariff and cost models
  • Parallelised Reliability Assessment using multiple cores

Optimal Remote Controlled Switch (RCS) Placement

  • Determination of optimal number and locations for RCS installation for improvement of system reliability
  • Economic assessment for various objective functions

Optimal Manual Restoration

  • Calculation of optimal switching scheme for manual power restoration phase

Optimal Recloser Placement

  • Optimal locations for reclosers, to improve reliability indices

Generation Adequacy Analysis

  • Stochastic assessment of system supply capabilities (loss of load probabilities, capacity credit, etc.)
  • Consideration of generator outages and maintenance schedules (Monte Carlo), as well as load variation
  • Enhanced probabilistic models for wind generation
  • Rich suite of reporting and plotting tools

Loss of Grid Assessment

  • Risk assessment for loss of grid supply to critical power stations