The equivalent load in phase coordinates is given by a constant active and reactive power. Based on the magnitude of the load power and voltage, a direct transfer matrix is calculated.

In fig. 1 is an equivalent constant load equivalent circuit. Resistance is determined only in a direct sequence and depends on the total load power.

Fig. 1. Equivalent load equivalent circuit

In phase coordinates, the equivalent load is described by the direct transfer matrix

,

where , , , , *U *– equivalent load voltage, – equivalent load power.

The attached file shows the calculation of the equivalent load form matrix in Matlab: A_load.m