A New Hybrid Nelder-Mead Particle Swarm Optimization for Coordination Optimization of Directional Overcurrent Relays

Algorithm 1

Pseudocode of the proposed hybrid NM-PSO algorithm.

1. Initialization. Generate a population of size N (N > (n + 1)).

Repeat

2. Constraint handling method

 2.1 The Gradient Repair Method. Repair particles that violate the constraints by

  directing the infeasible solution toward the feasible region.

 2.2 Identify solutions (that fulfill the constraint conditions) and arrange them in the

  order of good to bad.

3. Nelder-Mead Method. Apply NM operator to the top n + 1 particles and update the

  (n + 1)th particle.

4. PSO Method. Apply PSO operator for updating the 𝑁 particles.

 4.1 Selection. Select the global best particle and the neighborhood best particle from

  the population.

 4.2 Velocity Update. Apply velocity updates to the 𝑁 particles

until the condition is fulfilled.