The objective of this project is to develop a sensorless control solution for SPMSM. After a brief introduction, the dynamic model of the system is established, followed by the design of a Field Oriented Control scheme. Next, a Closed-loop flux observer, a first-order sliding mode observer, a second-order sliding mode observer, and a first-order sliding mode observer in dq-reference frame are developed. Two compensation methods, a VSI voltage error compensator, and a feed-forward load torque compensator are introduced. The developed estimators are compared to each other in simulation using standardized testing. It was discovered that SMOdq has the best performance. The feed-forward torque compensator is proven to enhance the transient response. The voltage error compensator and the observer robustness are tested in the laboratory with good results. At last, the SMO was compared to the STO and showed similar trends as in simulations.