BEMF-MRAS Based Sensorless PMSM for Solar Irrigation Pump with Ancillary Load Services

There are two problems in permanent magnet synchronous motor (PMSM) driven irrigation pump system. The first one is the use of encoder or resolver to sense the rotor position and the second one is the absence of provision to deliver power to ancillary loads. Such a load is necessary and unavoidable as it includes lighting load, fan load, provision to charge battery, and other miscellaneous electronic loads. To overcome these problems, a back electromotive force (BEMF) based model reference adaptive system (MRAS) for sensorless control of PMSM operated solar irrigation pump system with provision for delivering power to ancillary load is presented in this paper. Although the active power based MRAS and rotor flux based MRAS give an accurate estimation of rotor speed information, the former is sensitive to speed error while the existence of integrators is the main issue of the former. These problems are overcome by the BEMF-MRAS, and thus it is used in this work. The performances of the presented system with BEMF based MRAS under various operating scenarios are acquired by using simulations, which are then validated by the experimental results.