Performance Evaluation and Comparison of a Low-Cost, PLL-Based Acquisition System under Off-Nominal Conditions

In the last years, strong changes of power network architectures and operation have led to make use of huge quantities of instrumentation, spread around the grid. In fact, there is a strong need to perform very accurate measurements of electrical quantities in many nodes of the network, mainly due to the strong penetration of distributed generation. Recently, also the main Italian utility has asked for such kind of instrumentation. Its main feature must be to perform accurate measurements in all actual conditions. Such conditions include the instrumentation operation during off-nominal condition of the network. To this purpose, in this paper, a low-cost acquisition system developed by the authors, is recalled. Then a full comparison with off-the-shelf products during ideal or not power source is provided. Obtained results highlight the potentialities of the developed system for its implementation in both laboratory or medium/low voltage networks.