Block Diagrams of Current Control Methods for Vector Control of AC Machines

Question 1
Present the block diagrams of the following current control methods related to vector control of AC
machines and describe the merits and demerits of each of those separately.
i. Three – phase Hysteresis control
ii. Stationary – Frame PI control
iii. Synchronous – Frame PI control
Solution
Figure 1: Three-phase hysteresis control block diagram
Merits

Figure 2:Stationary-Frame PI control
Figure 3:Synchronous -Frame PI control
Question 2
A permanent Magnet Synchronous Machine (PMSM) needs to be controlled using a vector control
scheme in synchronous coordinates. The first step in the process is to derive a mathematical model of
the machine. This needs to be developed in synchronous coordinates. The machine parameters are
given in the table below.
Parameter PMSMs in test rig
Rated Voltage/VAC 230
Induced emf/Vrms1-1/1000 rpm 42
Rated current/A 16.3
Rated torque/Nm 10.5