.. _hydraulic_couplings:

===================
Hydraulic Couplings
===================

Hydraulic couplings are used to model multiple reservoirs connected to the same hydraulic system.

There are 5 different hydraulic couplings, 3 who are connected to a plant, and 2 who are not connected to a plant.

`Notebook with examples <hydr-couplings-notebook.ipynb>`_.

Overview
========

.. image:: overview.excalidraw.png
    :scale: 70%
    :align: center

Station joined couplings
========================

100
---

Each reservoir is connected to their own "virtual" power plant.

* Station controlled discharge
* No flow between reservoirs
* Power plants connected to coupling
* Each power plant can have their own PQ-curves local discharge energy equivalents.
* Only 1 "virtual" power plant is allowed to be active at each time step.

.. image:: 100.excalidraw.png
    :scale: 50%
    :align: center

Example:

.. code-block:: json

    {
        "hydraulic_couplings": [
            {
                "name": "coupling_100"
            }
        ]
    }

.. collapse:: JSON model

  .. literalinclude:: 100.json
    :language: JSON


120
---

* Free flow between reservoirs
* Limited by tunnel/canal max flow rate
* Power plant connected to coupling

.. image:: 120.excalidraw.png
    :scale: 50%
    :align: center

Example:

.. code-block:: json

    {
        "hydraulic_couplings": [
            {
                "name": "coupling_120",
                "max_flow": 70
            }
        ]
    }

130
---

* Discharge limited by gates
* Limited by max flow rate in tunnel/canal
* Flow between reservoirs limited by gates
* Power plant connected to coupling

.. image:: 130.excalidraw.png
    :scale: 50%
    :align: center

Example:

.. code-block:: json

    {
        "hydraulic_couplings": [
            {
                "name": "coupling_130",
                "max_flow": 70,
                "gate_switch_frequency": 50
            }
        ]
    }


Reservoir joined couplings
==========================

200
---

* Free flow between reservoirs
* Limited by max flow rate in tunnel/penstock.
* Power plants connected to 0 or more reservoirs

.. image:: 200.excalidraw.png
    :scale: 50%
    :align: center

.. code-block:: json

    {
        "hydraulic_couplings": [
            {
                "name": "coupling_200",
                "max_flow": 70
            }
        ]
    }

300
---

* Discharge limited by gates
* Flow between reservoirs limited by max flow rate in tunnel/canal
* Power plants connected to 1 or more reservoirs

.. image:: 300.excalidraw.png
    :scale: 50%
    :align: center

.. code-block:: json

    {
        "hydraulic_couplings": [
            {
                "name": "coupling_300",
                "max_flow": 70,
                "gate_switch_frequency": 50
            }
        ]
    }

200+300 example
---------------

An example combining couplings 200 and 300 in 1 model.

.. image:: 200-300.excalidraw.png
    :scale: 50%
    :align: center

.. collapse:: JSON model with type 200 and type 300 couplings.

  .. literalinclude:: 200_300.json
    :language: JSON