Dynamics and Control of Electric Transmission and Microgrids

CFryze–Buchbolz–Depenbrock Method for Load Compensation

C.1 Introduction

We consider here a multi‐terminal load fed by nonsinusoidal and unbalanced voltages at the terminals. It is assumed that the source voltages are sinusoidal, but the load bus voltages are distorted due to the imbalance in the lines feeding the load and the nonlinear load characteristics. The compensator is connected in parallel with the loads and is designed to inject currents that will compensate the non‐active currents drawn by the load and this results in sinusoidal voltages at the load bus, if the source voltages are sinusoidal. The basic approach is to compute the desired currents in the line that will result in supplying the required (active) power to the load, which will lead to the algorithm for generating the compensator currents.

The method of compensation is based on the Fryze–Buchbolz–Depenbrock (FBD) approach [1] using time‐domain power theory [2].

C.2 Description of FBD Theory

In a single‐phase circuit (see Figure C.1) supplying a linear load (say an R‐L load made up of resistance and inductance), the power and reactive power supplied by a sinusoidal voltage source are well defined and are given below:

(C.1)

Here and are the rms quantities of the sinusoidal voltage and current, respectively. ...