Calibration of Programmable Loads

The Standards and Calibration Laboratory (SCL) in Hong Kong has developed a system for the calibration of programmable loads. A programmable load is commonly used to emulate DC or AC loads required to perform functional tests of batteries, photovoltaic cells, power supplies, inverters and transformers. In recent years, programmable loads have more new applications such as electric vehicle testing and regenerative energy system testing. Load regulation test, battery discharge measurement and transient tests can be automated by programmable loads, which load changes for these tests can be made without introducing significant switching transient. Programmable load settings and read back accuracy for constant current mode, constant resistance mode, constant voltage mode, constant power mode and power factor modele loads can also be tested. Details of the proposed AC and DC programmable load calibration system developed at SCL are described in the paper.