Operational reliability assessment of power systems based on bus voltage

Abstract

Bus voltage is a direct reliability indicator of a transmission network because it is related to system reactive and active power balance especially during a contingency state. This study proposes a technique to evaluate network operational reliability based on bus voltage. Two new voltage related bus reliability indices are proposed to represent bus reliability. Network reliability levels under various operating conditions and contingency states are evaluated and presented by probabilities of system voltage being in normal, under-voltage, critical and collapse zones. The probabilistic voltage margin to the collapse point for each bus is evaluated to provide information for system operator regarding the risk under system random failures and load uncertainty. The IEEE 30-bus system and a practical 220 kV Taiyuan power system in Shanxi Province of China have been analysed to illustrate the proposed techniques.

Strategic management of stochastic power losses in smart transmission grids

“…35,36 In this section, a method to evaluate power network operational reliability based on the voltage of busses is considered. 35,36 In this section, a method to evaluate power network operational reliability based on the voltage of busses is considered.…”

“…As bus voltage is associated with system active and reactive power balance, specifically during a contingency state (the list of contingencies is added in Appendix A), it can be an indicator of the reliability of a transmission network. 35,36 In this section, a method to evaluate power network operational reliability based on the voltage of busses is considered. Under different operating conditions and contingency states, the power system reliability is evaluated.…”

“…Reliability can be classified into four voltage zones-normal, under-voltage, critical, and collapse-based on the voltage limits and collapse voltage. 35,36 In this paper, the load scaling factor (k) is used to represent the collapse point. The load gap that moves power system condition from an operational point to collapse point is considered to be a reliability criterion.…”

“…Liang's algorithm provides a coordinated alternating current (AC) power flow control solution to the smart grid operation in an environment with high shortterm uncertainty and variability, but only the generator active and reactive power is controlled, and, to show that the proposed algorithm is effective, the obtained results are not compared with those obtained from local controller acts, such as large generators' automatic voltage regulators (AVRs), switched capacitor bank volt-ampere reactive (VAR) control relays (VCRs), and on-load tap changing (OLTC) transformers' AVRs. Studies 35,36 proposed a method to evaluate power system operational reliability based on the bus voltage. Owing to large demand and extension limitations of transmissio n networks, these networks operate under high stress.…”

“…As a result of such tension, reliability methods related to voltage instability and voltage collapse become unavoidable in the operation of transmission networks. 35 As bus voltage is specifically associated with system active and reactive power balance during a contingency state, it can be an indicator of reliability in a transmission network. Studies 35,36 proposed a method to evaluate power system operational reliability based on the bus voltage.…”