Patent ID: 8860342

Claim:
A system, comprising: a processor; a first module communicably connected to the processor, wherein the first module is configured for calculating: a q-axis voltage component based on the following equation: v q =r s i q +ω r λ pm +ω r L d i d where r s is a resistance associated with a stator of a motor, i q is a q-axis current component, ω r is a seed of the rotor of the motor, λ pm is a stator flux linkage, L d is a motor stator d-axis inductance and i d is a d-axis current component; and a d-axis voltage component based on the following equation: v d =r s i d −ω r L q i q where r s is a resistance associated with a stator of a motor, i d is a d-axis current component, ω r is a seed of the rotor of the motor, L q is a motor stator axis inductance and i q is a q-axis current component; a second module communicably connected to the processor, wherein the second module is configured for determining a voltage angle relative to the q-axis based on the following equation: Tan θ= V d /V q where θ is the voltage angle, V d is a d-axis voltage component and V q is a q-axis voltage component; and a third module communicably connected to the processor, wherein the third module is configured for: comparing the determined voltage angle to a predetermined value; outputting the determined voltage angle if the determined voltage angle is less than the predetermined value; and outputting the predetermined value if the predetermined value is less than the determined voltage angle.