A Three-Phase Harmonic Power Flow Algorithm Based on A Hybrid Approach

 Abstract— Steady-state simulation plays a vital role in power system analysis and design. Steady-state initialization is important for the startup of an electromagnetic transient simulation. One of the commonly used steady-state analysis is phasor analysis. If the system is free from harmonics, phasor analysis is accurate. However, when a nonlinear or time-varying component is present in the system, phasor analysis is inadequate because the impact of the harmonics on the operating point is not taken into account. This paper presents a new power flow algorithm based on both time and frequency domains, which is also called the hybrid analysis. The proposed power flow algorithm employs a time-domain method to model nonlinear components and time-varying components and uses a frequency domain method to handle linear and distributed elements. Although in the past work, hybrid approach has been used to obtain steady-state voltage and current waveforms of a nonlinear or time-varying system, it has not yet been used for a power flow analysis. In this paper, we will show how to extend the existing hybrid method to account for the power flow constraints, imposed by the generator and load buses. Moreover, the proposed method is more efficient, as compared to the existing method because one redundant Newton iteration loop is eliminated in the proposed hybrid method.