2019年電気学会産業応用部門大会

Y-119

Sector Identification Method of Space Vector Modulation
Using Boundary Line in Dual Inverter Motor Drive
Melinda Badriatul Fauziah*, Yoshiaki Oto, and Toshihiko Noguchi (Shizuoka University)
Keywords : dual inverter; space vector modulation; open-end winding motor; sector identification.

I. INTRODUCTION

III. SIMULATION RESULTThe sector identification in the space vector modulation(SVM) is required by a dual inverter motor drive to control
motor terminal voltages and a capacitor voltage regarding thecharging and discharging modes. There have been manymethods to identify the sector such as comparing the time
duration ratio of each voltage vector surrounding the reference
voltage vector [1]. This paper focuses on the detection of thereference voltage vector position in the dual inverter motor
drive by determining boundary line equations surrounding eachsector.

Some simulations are conducted in both lower and higher
modulation index conditions. In the lower modulation index
which is m, during 1 period, reference voltage vector is
located in sector 14, 24
4 as depicted in Fig. 3a. Sector
61, 62, 63 is passed sequentially byreference voltage vector during 1 period as depicted in Fig. 3b.
This condition indicates higher modulation index (m > 0.5).

II. PROPOSED METHOD
The open-end winding motor fed by a dual inverter isdepicted in Fig. 1. The left side is INV1 and the other side is
INV2 where the DC bus is replaced with a capacitor having ahalf DC-bus voltage of INV1. The sector identification is
proposed by using the space voltage vector as shown in Fig. 2.
The hexagon is divided into 6 regions with 60-deg phase zone
in which each region is also divided into 4 shaped sectors ofequilateral triangle. The region from 0 to 60 deg is called
region 1 and the sectors located in region 1 are sector 11, 12,13, and 14. Boundary lines, which are lines a, b, c, d, e, f
limiting the sector, are employed to identify the location of thereference voltage vector.
The equation of each boundary line can be calculated byconsidering the maximum voltage vector amplitude and thereference voltage vector decomposed intoaxis. Themaximum voltage vector amplitude can be obtained as follows:
V0
V30

V60
V90V120
V150

2V360

IV. CONCLUSION
The simulation of the sector identification has beenpresented. It can be confirmed that the proposed method can beachieved both in the lower and higher modulation index. The
future plan is to verify this method using an experimentalsetup.
REFERENCES[1]YCapacitor
150 V

Battery
300 V

V60in

V120inVVrefVcos

Overall boundary line equations :V =1 2#23

12Vdc , and(2)

2

#32
#33

V360in1223Vdc,(3)

(4)

sin

where Vref is a voltage vector, V and V are voltage vectors
decomposed intoaxis, and is a space vector angle. The
overall line equations are presented in Fig. 2.
For instance, if the reference voltage vector is located in the
sector 11, boundary line equations a, b, and d are required. The
sector can be selected using inequality equations of theboundary lines as shown in Fig. 2.

［ Y - 119 ］

#12

#54

#43

#52
#51

V =b

#13a

V

#64

#44d

#11

#14

#42

V = 3V

#13

#24
#34

1 22
1 22

V = 3V

#21
#22

#31

3V 1 223V 1 22V = 1 24V =4(1)Vdc ,where V0 V360 are large vectors, V30 V330 are medium vectors,
and V0in V360in are small vectors having a half magnitude ofthe large vector. Moreover, the voltage vector can be calculated
as follows:
VINV2Fig. 1. Dual inverter motor drive.

#41

V0inOpen-endwinding motor

INV13V330

IEEE Int. Conf.

on Pow. Elec. and Drive Sys., 2017, 1172-1177.

#12

#63

#14

#62

Vref
#11

#61
#53

VVV

1 243V 1 223V 1 22Fig. 2. Space voltage vectors and proposed sector identification.
Sector

Sector

60

60

5050

40

4030302020
100.071875

0.075 0.078125 0.08125
Time (s)0.071875

0.075Time (s)0.078125(a) Lower modulation index.
(b) Higher modulation index.
Fig. 3. Sector identification results.

Ⓒ 2019 IEE Japan