C4-4
Experimental Result of Flux Linkage Identification of IPM Motorby Focusing on Current Norm
Xiang Ji, Toshihiko Noguchi (Shizuoka University)

Table 1. Experimental test conditions.
Ψ0.0674 Wb
Ld0.013 H

1. Introduction
Magnetic flux linkage is one of the main parameters of aninterior permanent magnet (IPM) motor.

A novel parameter(1)

identification technique has been proposed by the authors . To
confirm effectiveness of the flux linkage identification proposed inL̂d0.0 H

Kpq
Kpd

1.0 V/A
1.0 V/A300 r/minωthe past work, this paper presents the experiment result and1R+sLdid∗

evaluates the identification error.

2. Flux Linkage Identification Technique and Result
Figure 1 shows the configuration of the proposed identification

ωL̂qωLq

ωL̂d

ωLd1
Riq∗

technique. The q-axis current control loop employs a P regulator
instead of a PI regulator and d-axis inherently does the PI regulator.

1Rid∗

ωL̂dregulator. To separate the effect of Ψ from influence of mismatch
According to this(1)(2)

K Pq + R

Inmagnetic (A)+iq* K Pq

The second term of (2) disturbs identification of Ψ indicated in
the first term. To obtain only the first term of (2), it is necessary

True Value

0.02

0.06720.06800.0688Fig. 3. Current norm characteristic of Ψ.

iq∗ and Kpq to theMagnetic Flux Linkage (Wb)identification. By giving the same values as

d-axis current control loop, the second term of (2) can be known
Equation (3) shows thiscalculation.
(3)

term in (2). is shown in Fig. 3, and experimental result is alsoThe two curves show

similar properties and reach the minimum when Ψ in the controller
is equal to the true value.
Figure 4 shows an experimental result of the Ψ identification.
The identification result converges to 0.0680Wb by hill-climbing
method whereas the true value is 0.0674Wb whose identification

0.069

Magnetic Flux Linkage

0.068
0.067
0.066
0.065

010000

20000

30000

time (ms)The current norm characteristic modified by eliminating the second
compared with the simulation result.

0.04

Magnetic Flux Linkage (Wb)

Figure 2 shows the simulator of the second term in (2) after Lq

iq* K Pq
i* Kid _ rec = d Pd =K Pd + R K Pq + R

Simulation Characteristic
Expermental Characteristic

0.0664scheme.

and be recoded by the d-axis loop.

0.06

0.00

to eliminate the value of the second term by means of the following

error is 1.0 %.

ωψω ψˆ

Fig. 2. Second term simulator after Lq identification.

id = id* = 0K Pq + Riq

1
R + sLq

Mathematical expressions of id and iq can be derived

from Fig. 1 as shown in (1) and (2).

iq =idωLdiq∗situation, the system can perfectly eliminate the effect of theωc (ψˆ − ψ )ωFig. 1. Proposed identification system.

follows to its command with no steady state error because of the PI

detuned Ld.

iqψ

ψ̂

ω

Therefore, the q-axis current is influenced by the mismatches of theflux linkage Ψ and the d-axis inductance Ld. The d-axis currentof Ld, the d-axis current command is set to zero.

idFig. 4. Ψ identification result.

3. Conclusion
This paper has discussed the off-line Ψ identification techniqueand presented the experimental result. The proposed technique
can identify Ψ within the error of approximately ±1.0 %.
References(1)

X. Ji, T. Noguchi: “Off-line Parameter Identification of Interior
Permanent Magnet Motor by Searching Minimum Point of Current
Norm Characteristics,” IEEE SPEEDAM, EMD0064, 2014 (Italy).

平成 26 年度 電気・電子・情報関係学会東海支部連合大会（2014 年 9 月 8 日～ 9 日 於中京大学 名古屋キャンパス 1 号館）