Page 129 - Mathematical Models and Algorithms for Power System Optimization

New Algorithms Related to Power Flow 119

systems indicate that the algorithm proposed in this chapter can effectively improve the
convergence of the ill-conditioned power flow calculation in a large-scale system. It
provides an alternative algorithm for power flow calculation in the power system.
(2) This chapter proposes a new algorithm for solving the discrete OPF problem. This
algorithm can systematically process discrete variables such as transformer tap ratio, and
number of capacitor and reactor banks in the actual-scale discrete OPF problem.
The results of calculation used for an actual system show that the algorithm proposed is
effective. The characteristics of this algorithm include:
1. The algorithm can treat the tap ratio, and number of capacitor and reactor banks as
discrete variables.
2. The approximate mixed-integer LP algorithm (see Appendix A) can be used to solve
the actual-scale discrete OPF problem.
3. The SLP calculation technique is used to obtain the power flow solution that satisfies
the power flow equation.
4. The bounds of variable variation are adjusted to improve the linear approximation
accuracy of the power flow equation.
The discrete feasible near-optimal solution can be obtained by the proposed algorithm. When
the initial values are rounded off from the integer variable of the traditional OPF algorithm, the
solution is infeasible. In this case, the algorithm is particularly effective.