Principles of modular harmonic power flow methodology

The generalisation and refinement of a very efficient modular harmonic power flow (MHPF) methodology, initially available for simple components only, is presented. Its capabilities have been extended to three-phase systems that may include: nonlinear elements, such as generators; components with distributed and frequency-dependent parameters, as in the case of transmission lines; and switched components, exemplified by a thyristor controlled series capacitance (TCSC). The exact modelling of complex components is carried out individually in the time domain using Poincare acceleration for the fast and accurate calculation of the steady state. An incremental harmonic domain admittance matrix for the whole system is then used in an iterative process to obtain a system-wide solution. Numerical results for a small system serve to illustrate some details of the MHPF