Run Function

pandapower.grid_equivalents.get_equivalent.get_equivalent(net, eq_type, boundary_buses, internal_buses, return_internal=True, show_computing_time=False, ward_type='ward_injection', adapt_va_degree=False, calculate_voltage_angles=True, allow_net_change_for_convergence=False, runpp_fct=_runpp_except_voltage_angles, **kwargs)

This function calculates and implements the rei or ward/xward network equivalents.

Attention

• Power flow results in the given pandapower net are mandatory.

Known REI equivalents problems:

• shift_degree != 0 of trafos and trafo3ws lead to errors or wrong results

• despite ‘adapt_va_degree’, va_degree at the slack bus showed deviations within large grids

• with large, real grids small deviations in the power flow results occured, in small grids the results fit perfectly

Parameters:

• function. (**net** - The pandapower network including power flow results will not be changed during this)

• **eq_type** (string) –

  The following methods are available:

  • ”rei”: The idea of rei equivalent is to aggregate the power and current injection of the external buses to one or more fictitious radial, equivalent and independent (rei) nodes. There are three types of the rei-node in this routine, i.e. the reserved load, the reserved sgen and the reserved gen (also ext_grid). According to the demand, these elements (load, sgen and gen) are considered in the function “_create_net_zpbn” integrated or separately.

  • ”ward”: The ward-type equivalent represents the external network with some equivalent impedance, shunts and power injections at boundary buses. The equivalent power injections represent the power of the elements (load, sgen and gen), which are removed by the equivalent calculation.

  • ”xward”: The xward equivalent is an extended variation of the ward equivalent. Addition to the ward-representation, a fictitious PV node (generator) is added with zero active power injection at every boundary bus. The voltage of the PV node is set according to the boundary bus voltage.

  ward/xward has two mothods to develop an equivalent circuits, i.e. the injection method and the admittance method. In the admittance method, all the bus power injections in the external networks are converted into shunt admittance before network equivalent. That is the only difference between these two methods. With the help of the function “adapt_net”, these methods are configurable.

• **boundary_buses** (iterable)

• **internal_buses** (iterable)

• **return_internal** (bool, True) – If True, the internal network is reserved in the final equivalent network; otherwise only the external network is the output.

• **show_computing_time** (bool, False)

• **ward_type** (str, "ward_injection") – ward and xward proposed two mothods called the Ward Injection method and the Ward Admittance method to develop equivalent circuits. The only difference between these methods is that in the Ward Admittance method, all bus power in the external networks are converted into shunt admittances before network equivalent.

• **adapt_va_degree** (bool, None) - if True, in add_ext_grids_to_boundaries(), the va_degree of the additional ext_grids (if needed)

• **allow_net_change_for_convergence** (bool, False) - if the net doesn't converge at the first internal power flow, which is in add_ext_grids_to_boundaries()

• **calculate_voltage_angles** (bool, True) - parameter passed to internal runpp()

• arguments (****kwargs** - key word)

• sgen_separate (such as)

• load_separate

• gen_separate

• group_name.

Returns:

net_eq - The equivalent network in pandapower format