Determination of Voltage Stabilityin Distribution Network Using ANN Technique

Abstract

Voltage stability condition, reliability and service quality are the important parameters of a distribution system which need to be satisfied from the customer point of view.To measure voltage stability of distribution network a voltage stability index is presented in this paper. Voltage stability improvement of network is facilated by network reconfiguration and voltage stability level is quantified by voltage stability index. Network reconfiguration is a process which alters the feeder topological structure by changing the open/close status of the sectionalizing (normally closed) and ties switches (normally open) in the system. In this work, a two stage search of switching option i.e. local search and global search is implemented to achieve desired network configuration. A multilayer ANN model with Error Back Propagation Learning (EBPL) algorithm is simulated for global search to obtained optimal set of candidate switching. The proposed scheme is tested on an 11 kV practical radial distribution system consisting of 52 buses. After reconfiguration, better voltage stable condition of the system is attained. Active power loss of the system is reduced from 0.854 MW to 0.485 MW and reactive power loss of the system is reduced from 0.355MVar to 0.199MVar after achieving optimal configuration.

Application of Bird Swarm Algorithm for Allocation of Distributed Generation in an Indian Practical Distribution Network

“…The detailed specifications of this test system which is portrayed in Fig. 2 [22] are given in Table 3 and Appendix A. This test RDN is an arrangement of three feeders consists of total 52 nodes and 51 branches.…”

Determination of Generator Steady State Stability Limit for Multimachine System based on Network Losses Concept

“…Calculation result for the current value I of the observed generator using Equation 6 is 665.358 A. iv. The r eq value and the x eq value can calculate using Equation 7, Equation 8 and Equation 9, and we get 0.0000092792 j 0.00199184. v. We can determine the maximum generation of observed generator which is the generator steady-state stability limit using (3), and be obtained 668.929 MW vi. Repeat this procedure for all generators.…”

“…Maximum generation of generator is influenced by several factors: source voltage, phase angle and networks impedance value [8]. Equivalent network impedance can be determined by knowing the losses in the network, then the multimachine system can be changed into SMIB system with an equivalent impedance and an equivalent load.…”

“…Equivalent network impedance can be determined by knowing the losses in the network, then the multimachine system can be changed into SMIB system with an equivalent impedance and an equivalent load. Note that the determination of equivalent impedance value using losses concept has used in [8] and [9], but the change from the multimachine system to Single Machine to Infinite Bus (SMIB) system is not provided. Maximum generation of generator is a generator steady state stability limit that can be calculated after the network impedance is obtained.…”

Circuit theory approach for voltage stability assessment of reconfigured power network

“…It can be done by improving voltage stability of the system by minimising power losses. Voltage stability analysis of power network is dealt seriously as poor voltage stability may lead to voltage collapse and hence outage and gradually total black out of the system [1]. Voltage stability is often analysed using load flow method which involves numerous load flow solutions under both normal and faulted conditions.…”