Fig.1

Relationship of frames

Fig.2

Block diagram of PLL observer of position

Fig.3

High-frequency voltage signals

Fig.4

Current response with ideal high-frequency voltage injection

Fig.5

Current response with actual high-frequency voltage injection

Fig.6

d axis differential high-frequency response current

Fig.7

Fitting curve of cross saturation angle φ vs iq

Fig.8

System control diagram of proposed method

Fig.9

Deadbeat adaptive amplitude regulator

Fig.10

Bode of adaptive amplitude-phase control loop

Fig.11

Experiment platform of PMSM control system

Table 1

Parameters of PMSM system

Fig.12

Control diagram of fixed amplitude square wave voltage injection method

Fig.13

Dynamic response of speed

Fig.14

Dynamic response of position estimation with proposed method

Fig.15

Dynamic response of position estimation with pulse injection

Fig.16

Rotor position error after loading

Fig.17

Comparative results of position estimation at 50 r·min-1

Fig.18

Comparative results of position estimation at 100 r·min-1

Fig.19

Comparative results of position estimation at 150 r·min-1

Fig.20

Comparison results with acceleration and deceleration

Fig.21

Estimation performance of fixed amplitude square wave voltage injection at 50% rated load

Fig.22

Position estimation performance of proposed method at 50% rated load

Fig.23

Estimation performance of fixed amplitude square wave voltage injection at 100% rated load

Fig.24

Position estimation performance of proposed method at 100% rated load

Fig.25

Relationship between injected voltage and high-frequency response current