Underground cable

This section describes underground cable

Similar to Transmission line component, the properties of Underground cable can be defined in three ways, changing the Model definition to Geometry, RLC or Sequence. Properties window of underground cable for all cases of Model definitionis shown in Figure 1, on a) Geometry properties window, Figure 2 on b) RLC properties window and Figure 3 on c) Sequence properties window.

Definition of R, L and C matrices in phase domain will be shown on L matrix, the same way can be applied to R, and C matrix. Underground cable component for RLC parameters definition requires nested python list (matrix) [[Laa, Lab, Lac], [Lba, Lbb, Lbc], [Lca, Lcb, Lcc]], where diagonal elements Laa, Lbb, Lcc represent self-inductances of each phase, and off-diagonal elements represent mutual coupling inductances between phases.

Definition of R, L and C matrices in sequence domain will be shown on L matrix, where the same way can be applied to R, and C matrix. Underground cable component for sequence parameters definition requires nested python list (matrix) [[L00, L01, L02], [L10, L11, L12], [L20, L21, L22]], where diagonal elements L00, L11, L22 represent inductances of zero, positive and negative sequence, respectively. Off-diagonal elements represent mutual couplings between sequences.

Figure 1: Properties window of underground cable with Geometry

Figure 2: Properties window of underground cable with RLC

Figure 3: Properties window of underground cable with Sequence Model definition

The property Number of phases defines the number of phases of the component, which can range from 1 to 3. The Sequence model definition only supports three phases. This is why the number of phases has to be set to three if the user wants to switch to this model definition. Properties input can be in metric or imperial unit systems. The preferred one can be chosen in combo box Unit system. By default it is set to imperial.

Figure 4: Symbol

Figure 5: Schematic diagram of three phase underground cable with RL coupled model

Figure 6: Schematic diagram of three phase underground cable with PI model