# Pandapower converter The pandapower converter can convert the pandapower `net` to power-grid-model input data. It also converts the power flow output of power-grid-model into the `res_*` Dataframes in the pandapower `net`. The converter can be used in a similar way as described in [Converters](converter.md). ## Cross referencing Due to differences between the power-grid-model and pandapower, some components in one model are modeled as multiple components in the other or vise versa. An example on how to cross-reference can be found in the [pandapower conversion example](../examples/pandapower_example.ipynb#cross-referencing-objects). ## Defaults If any of the essential tap attributes: `tap_pos`, `tap_nom`, `tap_side` are not available then the tap feature for transformers are disabled by setting `tap_nom=tap_pos=0` via conversion. If a `vector_group` is not available for transformer then a default is set in conversion as `YNyn` for even clocks and `DYn` for odd clocks. Similarly for three winding transformer, `YNynyn` is set for even clocks of `shift_mv_degree` and `shift_lv_degree`. If the clocks are odd, then the vector group is converted as `YNynd`, `YNdyn` or `YNdd`. ## Modeling differences The user must be aware of following unsupported features or differences in conversion. * Currently, the conversions only support powerflow calculations and their relevant attributes. * Any feature involving a PV bus, i.e., generator, DC line are unsupported as of now. In addition, the following component-specific modeling differences exist. ### Load Delta type of loads, `type="delta"` are not supported in power-grid-model. ### Switch The features regarding `in_ka` and `z_ohm` attributes are currently unsupported. ### External grid The external grid is modeled with a source impedance all sequence components in power-grid-model. Whereas it is only present in negative and zero sequence networks in pandapower. Hence, this impedance value has to be mentioned in the power-flow calculation when using the power-grid-model power flow calculation. ### Transformer Custom zero sequence parameters `vk0_percent` and `vkr0_percent` in transformers are not supported. The same ones as positive sequence admittance is used in power-grid-model. However, `mag0_percent` and `mag0_rx` are fetched from `pandapower`. In case `vk0_percent` is different from `vk_percent` all zero sequence parameters are ignored. **For `pandapower<3.4.0` if installed, `mag0_percent` is treated as a ratio not as a percent in line with definition of `pandapower<3.4.0`. While for `pandapower>=3.4.0` or where `pandapower` is not installed, `mag0_percent` is treated as a percent.** The changing of impedance by the means of characteristics in `net.characteristic` is not directly supported. The phase shift in angle by transforermers by the `shift_degree` attribute only supports clock values in PGM. The `tap_phase_shifter` transformer and shifting of angles with tap via `tap_step_degree` are features not added in power-grid-model yet. The default for transformer model to be used in pandapower is `t` model but power-grid-model supports only `pi` model of transformer hence this may create a minor difference calculation. ### Three winding transformer Custom zero sequence parameters in three winding transformers are not supported. The differences defined in [Transformer](#transformer) are applicable here as well. Additionally, tap connection at star point, i.e., `tap_at_star_point` is not supported.