# Dividing circuits using coupling components

This section describes dividing circuits using coupling components

The idea behind dividing circuits is to allow the user to maximize the use of available SPCs, i.e. that one electrical circuit is to be divided into several sub-circuits, each mapped to a different SPC. Even though sub-circuits are executed in parallel, variables they share are updated in each computation cycle. Each sub-circuit may contain multiple power electronics converters (inverters, rectifiers, bucks, boosts) up to the maximal supported overall weight (typically 3, see Circuit solver configurations! for more details), and a certain number of passive components (resistors, inductors, capacitors, etc.), sources and measurements.

The desired circuit is divided into sub-circuits by means of “Coupling components” which can be found in the Typhoon HIL library (Figure 1). Figure 1. Coupling components in the Schematic Editor

There are three types of coupling components: the coupling component, the three-phase coupling component, and the four phase coupling component.

It is important to note that placement of a coupling component in the circuit is defined by the user.

The question is where to position Coupling component? If we keep in mind that coupling effectively splits one circuit into two sub-circuits, while each sub-circuit can handle converters weighting 3 in total, the most obvious and the most frequent choice is to place the Coupling component into the DC link, between two converters as shown in Figure 2.

It should be noted that the electrical circuit in Figure 2 consists of two sub-circuits connected by a coupling component. Sub-circuit 1 encompasses sources and inductors as a grid, three-phase rectifier (overall weight is 3) and several passive components and measurements, while Sub-circuit 2 is composed of a three-phase inverter, machine and measurements. Figure 2. Example of dividing a circuit into sub-circuits using a coupling component

The circuit in Figure 3 is divided by a three-phase coupling component. In the left sub-circuit there is a three-phase inverter, which has a weight of 3, while in the right sub-circuit there are no power electronics switching blocks: only passive components, sources and a contactor. Figure 3. Example of dividing a circuit into sub-circuits using a three-phase coupling component

The circuit in Figure 4 is divided by a four-phase coupling component. In the left sub-circuit there is a three-phase, three-level NPC inverter, which has a weight of 3, while in the right sub-circuit there are no power electronics switching blocks: only passive components, sources and a contactor. A four-phase coupling is useful when there is a need for the "fourth wire", as in the example below. Figure 4. Example of dividing a circuit into sub-circuits using a four-phase coupling component

In Figure 5 , there are no coupling components. The weight of the boost converter is 1, the weight of the single-phase converter is 2, which is 3 in total. Also, there is only one PV panel.