Design and implementation of a low cost Solar Panel emulator

Maximum Power Point Tracking (MPPT) is an essential element of a PV system. Bench power supplies provide a reasonable approximation of solar panel behavior and can be used for initial testing. However, detailed testing with actual solar panels is required to accurately establish the performance of MPPTs. This could be a difficult and time consuming task, especially for medium and high power ratings, owing to constraining factors such as panel sizes, panel availability, testing area, daylight hours etc. An alternative to this is the use of Solar Panel Emulators (SPEs) which mimic the behavior of the panel with a reasonable accuracy. These emulators can be used to test circuits indoors for a variety of power ratings and I-V profiles while being significantly smaller in size. In this paper, we have designed and implemented a medium power SPE based on diode approximation model. By minimizing component usage, the cost of the emulator is largely reduced. The proposed circuit is simulated and then tested with loads of up to 60W with satisfactory results.