Connections

The connections is one of the main methods of the LtmApi. It is used to connect objects. For example:

• Areas to DC Lines, Hydro power, Loads

• topology of detailed hydropower modules in API Waterways and hydro topology

Connections parameters

Parameter	Datatype	Description
from	string	name of object from connection point
to	string	name of object to connection point
comment	string	optional comment

Click arrow-head to see connections examples below.

Connections examples

"connections": [
    {
        "from": "pumpekraft", // area
        "to": "PUMPE_TEV_DC"  // dc_line
    },
    {
        "from": "market_step", // market step
        "to": "pumpekraft"     // area
    },
    {
        "from": "PUMPE_TEV_DC", // dc_line
        "to": "tev"             // area
    },
    {
        "from": "FLAT",         // load
        "to": "pumpekraft"      // area
    },
    {
        "from": "upper_main",   // reservoir
        "to": "pumpekraft"      // area
    },
    {
        "from": "upper_main",   // reservoir
        "to": "plant"           // hydropower plant
    }
]

Common attributes

This section gives short descriptions of common attributes not described elsewhere in the LtmApi documentation.

ownership

ownership parameters

Parameter	Datatype	Description
ownership	float	Optional, the ownership share of the system element in percent. Default value is 100 %.

The production in the power plants is scaled relative to the ownership, only the energy equivalent (discharge curve) is scaled. However, it is possible to extract the results for the specified ownership of the system or the total system.

inflow_series

The inflow_series parameters are listed in the table below.

Inflow time series parameters

Parameter	Datatype	Description
name	string	Object name
series	Txy	An inflow series can be defined and used as a reference on Plant or Reservoir. Unit is [m3/s]. See also Inflow.

Examples

Minimal example is provided below (click arrow-head to uncollapse).

inflow_series

"inflow_series": [
    {
        "name": "yearly_inflow_profile",
        "series": {
            "timestamps": [
                "1981-01-01T00:00:00Z",
                "1982-01-01T00:00:00Z",
                "1983-01-01T00:00:00Z",
                "1984-01-01T00:00:00Z",
                "1985-01-01T00:00:00Z",
                "1986-01-01T00:00:00Z",
                "1987-01-01T00:00:00Z",
                "1988-01-01T00:00:00Z",
            ],
            "scenarios": [
                [
                    0.47,
                    0.49,
                    0.40,
                    0.43,
                    0.39,
                    0.46,
                    0.44,
                    0.43
                ]
            ]
        }
    }
]

Usage example for plant is below (click arrow-head to uncollapse).

plant_inflow_series

"plants": [
  {
      "name": "plant",
      "discharge_energy_equivalent": {
          "scenarios": [
              [
                  0.12
              ]
          ]
      },
      "pq_curves": {
          "2024-01-01T00:00:00Z": {
              "y": [
                  0.0,
                  9.89
              ],
              "x": [
                  0.0,
                  24.6
              ]
          }
      },
      "average_unregulated_inflow": 0.6,
      "gross_head": 40.0,
      "tailrace_elevation": 1030,
      "unregulated_inflow_name": "yearly_inflow_profile"
  }
]

Similarly, using an inflow_series on a reservoir object is performed by the regulated_inflow_name attribute.