A benchmark test system for testing frequency dependent network equivalents for electromagnetic simulations

The complexity of modern power systems often makes it impractical to model it in its entirety for electromagnetic transient studies. Therefore areas outside the immediate area of interest must be represented by some form of frequency dependent network equivalent (FDNE). The equivalent must be “frequency dependent”, that is match the frequency response of the system it represents, if it is to faithfully represent it. This paper presents a z-domain rational function formulation for developing a FDNE and demonstrates the use of it for the assessment of the steady-state and transient response of the Lower South Island of New Zealand. This paper also shows the accuracy that can be expected from using FDNEs as well as providing a test system for other researchers to benchmark their work against. This is achieved by using a well publicized test system (Lower South Island of New Zealand) the parameters of which are readily available as well as providing complete information of the developed FDNE.