BasicLoad

Basic Load

The BasicLoad class serves as a basic, constant impedance power load.

Usage

• The input design parameters that must be specified by the modeler when creating an instance of the BasicLoad component is the complex impedance, Z, in Ohms (complex).

• This component supports DC and AC (single or multiphase) power. At instantiation, this component's power type is unspecified. NPSS Power System Components need to have a power type in order to correctly run power calculations. For this component, the power type is typically set by calling the findSourcesAndPropagate() method at the top level assembly (see ElectricPort).

• This component does not contain a node, and so starts each iteration with its port voltages unknown. The NPSS Power System Library requires that all components that contain nodes all have a prePass() method specified that pushes node voltage information, via their ports to all components that do not contain nodes and so do not know their voltages. The intent is that after all component prePass methods are automatically called, all components in the system will then have port voltages specified. Then during the normal iteration, components that don't contain nodes such as this one, will execute first. These components typically transmit power from one node to another and do not transform it from one kind to another (e.g. cables and breaker). These execute first in the solver sequence, and inside their calculate() methods, they calculate their currents, which are then passed via the ports, to all other components in the circuit. So after these nodeless transmission components execute, all electric port voltages and currents should be specified, and so all other components are free to run.

• This component is a circuit component and, at this time, has not been set up to include thermal models.

• Also note that this component has an output port. This (for the example the component is used for) represents a return path (a node with voltage = 0).

• Solver independents and dependents are not used in the BasicLoad component, and there is no sizing logic included in this component.