Electronically adjustable load for testing three phase AC systems

Some equipment such as AC voltage sources, power generators, inverters, and others converters have to be exhaustively tested before being used. To implement these tests it is necessary, in many cases, to use variable AC loads, such as passive (inductive, capacitive and resistive) and active loads (battery chargers and photovoltaic panels). This paper presents an analysis and design of an AC electronic load to emulate either purely active and reactive three-phase loads or other impedance combinations. This electronic variable load allows the user set precisely the amount of power required for practical experiments and bench tests. Furthermore, this work presents the modeling of a voltage source converter (VSC) and a buck converter, used to purpose of emulating a variable and adjustable load. Also it is discussed the compensators design to control the converter and is presented simulation results with the electronically adjustable load to active and reactive power consumption.