{
 "cells": [
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Unbalanced power flow calculation with pandapower\n",
    "\n",
    "We will create a simple three bus system to demonstrate how to run unbalanced power flow calculations with pandapower. First, we create the three buses as follows:"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 27,
   "metadata": {},
   "outputs": [],
   "source": [
    "import pandapower as pp\n",
    "\n",
    "net = pp.create_empty_network()\n",
    "b1  = pp.create_bus(net, 20.0)\n",
    "b2  = pp.create_bus(net, 0.4)\n",
    "b3  = pp.create_bus(net, 0.4)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "The external grid connection can then be created with the short-circuit parameters s_sc_max_mva and rx_max as well as the parameters x0x_max and r0x0_max that define the zero sequence impedances. The ext_grid parameters are all defined in the [ext_grid parameter documentation](https://pandapower.readthedocs.io/en/develop/elements/ext_grid.html#input-parameters)."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 28,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "0"
      ]
     },
     "execution_count": 28,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "pp.create_ext_grid(net, b1, s_sc_max_mva=1000, rx_max=0.1, x0x_max=1.0,\n",
    "                   r0x0_max=0.1)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "The transformer requires the additional parameters vk0_percent, vkr0_percent, mag0_percent, mag0_rx, vector_group and si0_hv_partial for unbalanced calculation. The transformer parameters are all defined in the [transformer parameter documentation](https://pandapower.readthedocs.io/en/develop/elements/trafo.html#input-parameters)."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 29,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "0"
      ]
     },
     "execution_count": 29,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "pp.create_transformer_from_parameters(net, b1, b2, sn_mva=0.63,\n",
    "                                      vn_hv_kv=20., vn_lv_kv=0.4,\n",
    "                                      vkr_percent=0.1, vk_percent=6,\n",
    "                                      vk0_percent=6, vkr0_percent=0.78125,\n",
    "                                      mag0_percent=100, mag0_rx=0.,\n",
    "                                      pfe_kw=0.1, i0_percent=0.1,\n",
    "                                      vector_group=\"Dyn\", shift_degree=150,\n",
    "                                      si0_hv_partial=0.9)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "For lines, the zero sequence impedances r0_ohm_per_km, x0_ohm_per_km and c0_nf_per_km are required in addition to the balanced parameters. The line parameters are all defined in the [line parameter documentation](https://pandapower.readthedocs.io/en/develop/elements/line.html#input-parameters)."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 30,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "0"
      ]
     },
     "execution_count": 30,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "pp.create_line_from_parameters(net, b2, b3, length_km=0.1, r0_ohm_per_km=0.0848,\n",
    "                               x0_ohm_per_km=0.4649556, c0_nf_per_km=230.6,\n",
    "                               max_i_ka=0.963, r_ohm_per_km=0.0212,\n",
    "                               x_ohm_per_km=0.1162389, c_nf_per_km= 230)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Finally, to create an unbalanced power flow, we create an asymmetric load. The input parameters are all defined in the [asymmetric load parameter documentation](https://pandapower.readthedocs.io/en/develop/elements/asymmetric_load.html#input-parameters)."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 31,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "0"
      ]
     },
     "execution_count": 31,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "pp.create_asymmetric_load(net, b3, p_a_mw=0.25, p_b_mw=0.18, p_c_mw=0.20, type=\"wye\")"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "We can now run an unbalanced power flow:"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 32,
   "metadata": {},
   "outputs": [],
   "source": [
    "pp.runpp_3ph(net)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "The results are stored in the result tables with suffix \"_3ph\", such as \"res_bus_3ph\", \"res_line_3ph\" etc.:"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 33,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
       "<div>\n",
       "<style scoped>\n",
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       "        vertical-align: middle;\n",
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       "\n",
       "    .dataframe tbody tr th {\n",
       "        vertical-align: top;\n",
       "    }\n",
       "\n",
       "    .dataframe thead th {\n",
       "        text-align: right;\n",
       "    }\n",
       "</style>\n",
       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th></th>\n",
       "      <th>vm_a_pu</th>\n",
       "      <th>va_a_degree</th>\n",
       "      <th>vm_b_pu</th>\n",
       "      <th>va_b_degree</th>\n",
       "      <th>vm_c_pu</th>\n",
       "      <th>va_c_degree</th>\n",
       "      <th>p_a_mw</th>\n",
       "      <th>q_a_mvar</th>\n",
       "      <th>p_b_mw</th>\n",
       "      <th>q_b_mvar</th>\n",
       "      <th>p_c_mw</th>\n",
       "      <th>q_c_mvar</th>\n",
       "      <th>unbalance_percent</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>0</th>\n",
       "      <td>0.999949</td>\n",
       "      <td>-0.003361</td>\n",
       "      <td>0.999975</td>\n",
       "      <td>-119.995771</td>\n",
       "      <td>1.000076</td>\n",
       "      <td>119.999132</td>\n",
       "      <td>0.23147</td>\n",
       "      <td>0.038112</td>\n",
       "      <td>0.190741</td>\n",
       "      <td>0.03422</td>\n",
       "      <td>0.214526</td>\n",
       "      <td>0.000889</td>\n",
       "      <td>0.007796</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>1</th>\n",
       "      <td>0.990115</td>\n",
       "      <td>-154.177654</td>\n",
       "      <td>0.996316</td>\n",
       "      <td>87.027718</td>\n",
       "      <td>0.995532</td>\n",
       "      <td>-33.324385</td>\n",
       "      <td>0.00000</td>\n",
       "      <td>0.000000</td>\n",
       "      <td>0.000000</td>\n",
       "      <td>0.00000</td>\n",
       "      <td>0.000000</td>\n",
       "      <td>0.000000</td>\n",
       "      <td>0.686963</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>2</th>\n",
       "      <td>0.977489</td>\n",
       "      <td>-158.242495</td>\n",
       "      <td>1.001535</td>\n",
       "      <td>85.148380</td>\n",
       "      <td>0.974531</td>\n",
       "      <td>-35.450453</td>\n",
       "      <td>-0.25000</td>\n",
       "      <td>-0.000000</td>\n",
       "      <td>-0.180000</td>\n",
       "      <td>-0.00000</td>\n",
       "      <td>-0.200000</td>\n",
       "      <td>-0.000000</td>\n",
       "      <td>1.221643</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>\n",
       "</div>"
      ],
      "text/plain": [
       "    vm_a_pu  va_a_degree   vm_b_pu  va_b_degree   vm_c_pu  va_c_degree  \\\n",
       "0  0.999949    -0.003361  0.999975  -119.995771  1.000076   119.999132   \n",
       "1  0.990115  -154.177654  0.996316    87.027718  0.995532   -33.324385   \n",
       "2  0.977489  -158.242495  1.001535    85.148380  0.974531   -35.450453   \n",
       "\n",
       "    p_a_mw  q_a_mvar    p_b_mw  q_b_mvar    p_c_mw  q_c_mvar  \\\n",
       "0  0.23147  0.038112  0.190741   0.03422  0.214526  0.000889   \n",
       "1  0.00000  0.000000  0.000000   0.00000  0.000000  0.000000   \n",
       "2 -0.25000 -0.000000 -0.180000  -0.00000 -0.200000 -0.000000   \n",
       "\n",
       "   unbalance_percent  \n",
       "0           0.007796  \n",
       "1           0.686963  \n",
       "2           1.221643  "
      ]
     },
     "execution_count": 33,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "net.res_bus_3ph"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "We can check the voltage in all phases as well as the unbalance percentage according to IEC 62749:"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 37,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
       "<div>\n",
       "<style scoped>\n",
       "    .dataframe tbody tr th:only-of-type {\n",
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       "\n",
       "    .dataframe tbody tr th {\n",
       "        vertical-align: top;\n",
       "    }\n",
       "\n",
       "    .dataframe thead th {\n",
       "        text-align: right;\n",
       "    }\n",
       "</style>\n",
       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th></th>\n",
       "      <th>vm_a_pu</th>\n",
       "      <th>vm_b_pu</th>\n",
       "      <th>vm_c_pu</th>\n",
       "      <th>unbalance_percent</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>0</th>\n",
       "      <td>0.999949</td>\n",
       "      <td>0.999975</td>\n",
       "      <td>1.000076</td>\n",
       "      <td>0.007796</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>1</th>\n",
       "      <td>0.990115</td>\n",
       "      <td>0.996316</td>\n",
       "      <td>0.995532</td>\n",
       "      <td>0.686963</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>2</th>\n",
       "      <td>0.977489</td>\n",
       "      <td>1.001535</td>\n",
       "      <td>0.974531</td>\n",
       "      <td>1.221643</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>\n",
       "</div>"
      ],
      "text/plain": [
       "    vm_a_pu   vm_b_pu   vm_c_pu  unbalance_percent\n",
       "0  0.999949  0.999975  1.000076           0.007796\n",
       "1  0.990115  0.996316  0.995532           0.686963\n",
       "2  0.977489  1.001535  0.974531           1.221643"
      ]
     },
     "execution_count": 37,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "net.res_bus_3ph[[\"vm_a_pu\", \"vm_b_pu\", \"vm_c_pu\", \"unbalance_percent\"]]"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "The line and trafo results provide currents and loadings in different phases or overall loading, which is defined as the maximum of all phase loadings."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 38,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
       "<div>\n",
       "<style scoped>\n",
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       "        vertical-align: middle;\n",
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       "\n",
       "    .dataframe tbody tr th {\n",
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       "    }\n",
       "\n",
       "    .dataframe thead th {\n",
       "        text-align: right;\n",
       "    }\n",
       "</style>\n",
       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th></th>\n",
       "      <th>i_a_from_ka</th>\n",
       "      <th>i_b_to_ka</th>\n",
       "      <th>loading_b_percent</th>\n",
       "      <th>loading_percent</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>0</th>\n",
       "      <td>1.107461</td>\n",
       "      <td>0.778228</td>\n",
       "      <td>80.812922</td>\n",
       "      <td>115.001163</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>\n",
       "</div>"
      ],
      "text/plain": [
       "   i_a_from_ka  i_b_to_ka  loading_b_percent  loading_percent\n",
       "0     1.107461   0.778228          80.812922       115.001163"
      ]
     },
     "execution_count": 38,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "net.res_line_3ph[[\"i_a_from_ka\", \"i_b_to_ka\", \"loading_b_percent\", \"loading_percent\"]]"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 39,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
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       "<style scoped>\n",
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       "\n",
       "    .dataframe tbody tr th {\n",
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       "    }\n",
       "\n",
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       "        text-align: right;\n",
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       "</style>\n",
       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th></th>\n",
       "      <th>i_a_hv_ka</th>\n",
       "      <th>i_b_lv_ka</th>\n",
       "      <th>loading_b_percent</th>\n",
       "      <th>loading_percent</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>0</th>\n",
       "      <td>0.020317</td>\n",
       "      <td>0.838315</td>\n",
       "      <td>92.281286</td>\n",
       "      <td>111.713642</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>\n",
       "</div>"
      ],
      "text/plain": [
       "   i_a_hv_ka  i_b_lv_ka  loading_b_percent  loading_percent\n",
       "0   0.020317   0.838315          92.281286       111.713642"
      ]
     },
     "execution_count": 39,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "net.res_trafo_3ph[[\"i_a_hv_ka\", \"i_b_lv_ka\", \"loading_b_percent\", \"loading_percent\"]]"
   ]
  }
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