Analysis of a switched and linear power amplifier for Power Hardware-in-the-Loop testing of Smartgrid systems

The integration of Distributed Energy Resources (DER) into the Smartgrid requires test techniques to ensure the reliability and security of the electric infrastructure. These test techniques have to be flexible enough to allow the needed diversity requirements of Smartgrids. Nowadays, Power Hardware-in-the-Loop (PHIL) is one of the best test techniques which offers an excellent trade-off between test fidelity and test coverage. PHIL systems are built up with a Digital Real-Time Simulator (DRTS) and a Power Amplifier (PA) to perform the test. However, they are not so widespread due to their high cost and the uncertainty to fulfil test hardware requirements in advance. This paper tackles this issue and describes a real case laboratory study to acquire a PA in order to perform particular Smartgrid tests in its facilities. Three different PHIL tests of Smartgrid systems are detailed, discussing the use of a switched and a linear PA to evaluate the stability and performance of each one. The results are analyzed in order to obtain the best PA according to the laboratory requirements.