Differences between the drive algorithms for BLDC, PMSM and IPMSM
A perminant magnet synchronous machine (PMSM) must be excited with an AC current for torque to be developed.
A Brush less DC (BLDC) PMSM has a backEMF profile which is trapizoidal in shape to maximise the peak torque but also to simplify the drive algorithm as they can be excited with a simple quasi square wave controller.
A Brush less AC (BLAC) machine has a sinusoidal backEMF profile and thus should be excited with a sinus current waveform
There are three types of BLAC machines
Surface Permanent Magnet (SPM). The rotor magnets are bonded to the rotor
Interior Permanent Magnet synchronous machines (IPMSM) where the magnets are mounted in slots of the rotor
Flux switching Permanent Magnet (FSPM). A cross between an SR and a IPMSM.
Fundamentally they are controlled exactly the same way. However  due to the fact there is a reluctance component associated with the IPMSM, the machines requires a slight amount of phase advance to provide a balanced torque profile. The motor also benefits from reluctance torque and thus can be more efficient than a SPM as it can produce slightly higher torque for the same current. Likewise they can operate at higher velocities due to the magnets are encased by the rotor