Connections¶

Connections model power flow paths between elements. They define how power moves through the network and can apply constraints, efficiency losses, and costs to that flow.

Connection class hierarchy¶

HAEO provides a hierarchy of connection types with increasing functionality:

classDiagram
    Connection <|-- PowerConnection
    Connection <|-- BatteryBalanceConnection

    class Connection {
        +source: str
        +target: str
        +power_source_target
        +power_target_source
        +power_into_source
        +power_into_target
    }

    class PowerConnection {
        +max_power_source_target
        +max_power_target_source
        +efficiency_source_target
        +efficiency_target_source
        +price_source_target
        +price_target_source
    }

    class BatteryBalanceConnection {
        +energy redistribution
    }

Connection types¶

Connection (base class): Lossless bidirectional power flow. Provides the fundamental power variables and interface that all connections share. Use when no efficiency, limits, or pricing are needed.

PowerConnection (extends Connection): Adds optional power limits, efficiency losses, and transfer costs. This is the primary connection type for most user-configured connections.

BatteryBalanceConnection: Specialized lossless energy redistribution between battery sections. Used internally by the Battery device to balance energy across SOC sections. Not typically used directly.

Common interface¶

All connection types provide these properties for node power balance calculations:

The power_into_* properties handle efficiency losses internally, so elements don't need to know about connection efficiency.

Design philosophy¶

Connections are kept separate from elements to enable flexible network topologies:

• Elements define what they do (store energy, generate power, consume power)
• Connections define how elements interact (power limits, efficiency, cost)

This separation allows the same element types to be connected in different ways depending on the physical system being modeled.

Next Steps¶