Reduction Method of Stopping Vibration for Compressorin Home Appliances
Taisuke Shioi, Takahiro Kumagai, Keisuke Kusaka, Jun-ichi, Itoh
Nagaoka University of Technology
1603-1, Kamitomioka-machi, Nagaoka, Niigata, JAPAN
Tel., Fax: +81 / (258) – 47.9533.
E-Mail: s183135@stn.nagaokaut.ac.jp
URL: http://itohserver01.nagaokaut.ac.jp/itohlab/en/index.html

Keywords«Permanent magnet motor», «Vibration suppression», «Three-phase motor drive», «Sensor-lesscontrol»

Abstract
This paper proposes a low-vibration stopping method by switching the free-run mode and the short-circuit
braking mode for compressors. The vibration is generated by the bounce of the rotor caused by the fluctuationof the load torque. The proposed method suppresses the rotor bounce by stopping the motor during the suction
process because the compressor does not generate large torque in the suction process. In order to stop the
motor during the suction process, the proposed method switches the operation mode form the free-run modeto the short-circuit braking mode at the Top Dead Center, which is starting point of the suction process.
Furthermore, the inrush current during the a short-circuit braking mode is suppressed by a hysteresis current
controller. The vibration is evaluated under four pressure conditions with the conventional method and the
proposed method. As the result, the proposed method achieved more than 58% reduction of the amplitude of
the vibration at all four pressure conditions. Notably, the proposed method reduced the amplitude of thevibration by 71% under the high-pressure condition.

Introduction
Recently, permanent magnet synchronous motors (PMSMs) are being increasingly employed to home
appliances thanks to its distinct advantages of high power density and high efficiency [1]-[9]. The
operation with low acoustic noise and low vibration is required since the home appliances such as
refrigerators and air conditioners are built into a living environment. The compressor in the home
appliances repeats the cycle of (suction) => (compression) => (ejection) for a heat exchange. These
repeated operations lead to a large load torque fluctuation and a large speed ripple of the motor. In
addition, a speed sensor and a position sensor cannot be attached on the compressor motor because theinside of the compressor is the high temperature and the high pressure. Furthermore, there is a limit to
the processing speed of the microcomputer from an aspect of the product cost.
Automatic start-stop control is applied in order to control the pressure of the compressor. This control
leads the reduction of the power consumption. On the other hand, the frequency of the start/stop
operation more increase than general purpose motors. Therefore, it is important for the compressor
motor to reduce the vibration not only under steady state but also under start and stop.
Under the steady state, some literatures have achieved to reduce the vibration by suppressing the speed
ripple due to the load torque fluctuation[10],[11]. The effect of the suppression method for vibration
depends on the accuracy of the estimated position because the most of these methods adopt the sensorless field oriented control (FOC). Generally, a back electromotive force (EMF) based position estimation
method is employed in the medium and the high speed region [12],[13]. However, the accuracy of theestimated position deteriorates in the low speed region because the back EMF becomes small[14].
Therefore, the effect of the reduction method of vibration based on the back EMF become worse under
the start and the stop. In addition, the sensor-less FOC requires expensive microcomputers for thecomplex calculations. Thus, it is not suitable for home appliances which adopts cheap microcomputersin order to save the cost.

During the start, the three-steps starting method is employed [15]. This method consists of the
preposition, the open-loop operation, and the sensor-less control. The motor outputs the torque which islarger than the load torque by the open-loop operation and sensor-less control. However, the vibrationof the compressor is generated by the load torque fluctuation because the period of the open-loop
operations cannot control the motor torque. Under the start, the load torque fluctuation is small because
the pressure of the ejection valve agrees with the suction valve in the compressor. Thus, the vibration
due to the load torque fluctuation is small. On the other hand, under the stop, the vibration due to theload torque fluctuation becomes large because the pressure of the ejection valve is higher than thesuction valve. Therefore, this paper focus on the stop which has the large vibration.
During the stop, the free-run method in which all switching devices are tern-off state is known as oneof the simplest stopping methods. In this method, the motor is stopped only by the load torque including
the mechanical loss because the output torque of the motor becomes zero. The free-run method leads tothe vibration of the compressor due to the speed ripple caused by the load torque fluctuation. In the [16],the vibration is reduced by changing switching pattern to the free-run mode after decelerating therotation speed. This method sets a delay time between receiving the stop signal and changing theswitching pattern to free-run mode. In the delay time, the motor is decelerated at the maximum
acceleration using the motor torque. In this method, the optimize delay time for the reduction of thevibration depends on the rotation speed and pressure of the compressor. Thus, when the rotation speed
and pressure are changed, this method cannot suppress the vibration. Therefore, the low-vibration
stopping method that is independent of the rotation speed and the pressure is necessary in order toreduced the vibration at stop.
This paper proposes a low-vibration stopping method, which is independent of the rotation speed andpressure condition. The originality of this paper is that the vibration is reduced by stopping the motor
during the suction process which does not generate the large torque. This method combines (i) the
deceleration mode using the free-run method and (ii) the stopping mode using the short-circuit braking.
In addition, the inrush current during the short-circuit braking is suppressed by a hysteresis current
controller. Furthermore, the proposed method is implemented with a cheap microcontroller because it
does not require the complex calculation. Therefore, the proposed method is suitable for the home
appliances.
This paper is organized as follows: firstly, the lord torque characteristics of the compressor is described.
Secondly, the cause of the vibration with conventional method is investigated. Next, the detail of the
proposed low-vibration stopping method is explained. Finally, the vibration is compared between theconventional method using free-run mode and the proposed method in the experiment.

Lord torque characteristics of compressor
Figure 1 shows the scheme drawings of the reciprocating compressor. The reciprocating compressor
compresses the refrigerants by repeating the reciprocating motion of a piston which connected to a rotor.
As shown in figure 1, the point where the operation of the compressor changes from the ejection to thesuction is defined as Top Dead Center (TDC). In addition, the point where the operation changes fromthe suction to compression is defined as Bottom Dead Center (BDC). This paper defines TDC as 0
degree of the crank angle and BDC as 180 degree of the crank angle.

Ejection
PistonPistonCon-rod

Con-rodCompression

Crankshaft

Crankshaft(a) Top dead center (TDC)(b)Bottom dead center ( BDC)
Fig.1. scheme drawings of reciprocating compressor.

Figure 2 shows the torque characteristics of the compressor, where Pd denotes the pressure of theejection valve and Ps denotes the pressure of the suction valve. As shown in the figure 2(a), the torqueis small during the suction process and it becomes large during the compression and the ejection. As
shown in the figure 2(b), the torque varies depending on the pressure of the compressor.

Investigation result of the vibration with conventional stopping method
Experimental conditions
This paper evaluates the vibration of the motor during the stop with the free-run method and proposed
stopping method. Firstly, this paper evaluates the vibration of the motor stops with the free-run method
in order to clarify the causes of the vibration.
Figure 3 shows the switching pattern of the inverter during the free-run mode in which all switch of
the inverter is off. Thus, the motor does not generate torque. Therefore, the motor is decelerated by only
the load torque. Note that the voltage of the output of the inverter agrees with the back EMF of the motorin the free-run mode.
Table 1 shows the parameters of the inverter and the motor. The pressure condition influences to thetorque characteristics of the compressor. It is necessary to measure the vibration at same pressure
conditions in order to compare the vibration at stop using the free-run method and the proposed method.
Thus, in this experiment, the motor is driven until the pressure in the compressor becomes constant inthis experiment. After that, the motor is stopped and the vibration is measured with an acceleration
sensor attached to the compressor. The pressure in the compressor and the rotation speed are determinedfrom the operation characteristics of the household refrigerators.
1.0

1.04

1.5

suction: T [p.u.]
TorqueT [N･m]1.2: T [p.u.]
TorqueT [N･m]0.8

ejectioncompression

0.6
0.9

0.4
0.6

Bottom dead center,
BDC(180 deg)

0.2
0.3

0

0

-0.2
-0.3

Top dead center,TDC(0 deg)
0
0

30

60

90
90

180
Crank angle [deg]

120

150
180
210
Crank Angle [deg]

240

270

270

300

330

360
360

Pd吸入0.05,吐出0.4= 0.4, Ps = 0.05 MPa
Pd吸入0.10,吐出0.4= 0.4, Ps = 0.1 MPa
Pd吸入0.05,吐出0.8= 0.8, Ps = 0.05 MPa
吸入0.10,吐出0.8
Pd = 0.8, Ps = 0.1 MPa

3.2
0.8
2.4
0.6
1.6
0.4
0.8
0.2

00

-0.8
-0.2
00

Bottom dead center,
BDC(180 deg)
0deg（上死点）

Top dead center,TDC(0 deg) 178.5deg（下死点）
30

60

90
90

150
180
210
240
Crank180
Angle [deg]Crank angle [deg]120

270 300

270

330

360
360

(a) Pressure characteristics of compressor. (b) Pressure characteristics in each pressure conditions.
Fig.2. Pressure characteristics of compressor.

Sup

Svp

Swp

VDC

M

Sun

Svn

Swn

Fig.3. switching pattern of free-run
Table 1. Experimental conditions.
Parameter
Rating rotation speed
Rating torque
Polar logarithmicWinding resistanced-axis inductace
q-axis inductace
DC-link voltage
Switching frequency
Dead time

Symbol

wn
Tn
P
R
Ld
Lq
Vdc
fsw
Td

Value
80 rps
0.237 N・m
3
6.2 W
76.3 mH
136 mH
280 V
16 kHz0.5 msInvestigation result of the vibration using free-run method
Figure 4 shows the output waveform of the acceleration sensor and the estimated rotation speed whenthe motor is stopped with the free-run method. The rotation speed is estimated from the back EMF
because the compressor does not be hanged the speed sensor. The rotation speed is decreased by theload torque in the free-run method. Therefore, a periodical change of the rotation speed is caused by theload torque shown in Figure 2. The rotation speed is sharply reduced during the compression and theejection process because the compressor generates a large torque in this period. The direction of therotation is reversed because the rotor bounces due to the load torque as shown in figure 4. In addition,
the output of the acceleration sensor becomes large after the rotation speed sharply reduced. As the resultof the figure 4, the vibration occurs due to the speed ripple and the rotor bounce caused by the load
torque fluctuation. In particular, the large vibration is generated after the rotor bounce. This paper
proposes the reduction method of the vibration by suppressing the rotor bounce which is main cause of
the vibration.

Proposed low-vibration stopping method
This paper proposes a low-vibration stopping method with switching the operation mode to the freerun mode and the short-circuit breaking. The proposed method suppresses the rotor bounce, whichcauses the large vibration by stopping the motor during the suction process. In order to stop the motor
during the suction process, the proposed method generates the brake torque with the short-circuit braking.
Figure 5 shows the main circuit configuration for the proposed method. This system requires three
voltage sensors in order to estimate the rotation speed and mechanical position. In addition, this system
requires three current sensors in order to control the amplitude of the current.
Figure 6 shows the switching pattern of the inverter during the short-circuit braking. In the short-circuit
braking, the output voltage of the inverter becomes zero. The motor is rapidly stopped by converting therotation energy of the motor into heat energy at the wire resistance. Note that in the short-circuit braking,the motor may be damaged by an overcurrent due to the back EMF. Therefore, it is necessary to control
the motor current in order to prevent the over current of the inverter.
The proposed method has two operation modes which are (i) the deceleration mode and (ii) the stopping
mode. During (i) the deceleration mode, the motor is decelerated with the free-run state and estimates
50
50
40
40
30
30
20
20
10
10
00
-10
-10
-1.0
20

30

Gate off

-0.8

-0.6

-0.4

-0.2

0.0

20
20

10
10

0

0

-10
20.0
20

Acceleration sensor output[m/s2]

Acceleration sensor output[m/s2]

Rotation
speed [rps]Rotation
speed [rps]

30

-10
-0.7

-0.6

10

10.0

10
0

-0.6

-0.5

(i)Vibration by
speed ripple

-0.5

-0.4

(ii)Vibration
by rebound

0

0.0

-10

200 ms/div

-20

-10

-10.0

50 ms/div-20-0.7

-20.0

-0.6

-0.6

-0.5

-0.5

-0.4

(a) Rotation speed and acceleration sensor output.
(b) Enlarged view at the rotor bounce point.
Fig.4. Rotation speed and acceleration sensor output when the motor is stopped with the free-run.

Sup

Svp

Swp

Sup
M

Sun

Svn

Swp

VDC

M

Sun

Swn

Svp

Svn

Swn

vu vv vw iu iv iw

Fig.5. Main circuit configuration for proposed method. Fig.6. Switching pattern of short circuit braking.

the rotation speed and TDC from the back EMF and the acceleration of the motor. When the rotation
speed becomes under the threshold value and rotor position agrees with TDC, the operation mode change
to (ii) the stopping mode. During (ii) the stopping mode, the motor is stopped with the short-circuit
braking.
Figure 7 shows the control block diagram of the proposed method. The proposed method consists of
the V/f control part for the steady state operation, the speed estimator, the operation mode selector, thecurrent controller, and the switching pattern selector. In the deceleration mode, the rotation speed and
TDC are estimated with the speed estimator and the operation mode selector. The operation mode ischanged according to the signal from the operation mode selector and the current controller.

Estimation method of the rotation speed and TDC
The proposed method estimates TDC from the acceleration and the phase of the motor. As shown infigure 3, the rotation speed sharply reduces only compression and ejection process in the free-run mode.
Thus, the acceleration becomes large during the compression and ejection process. Therefore, themechanical angle is estimated from the acceleration of the motor.
Figure 8 shows the block diagram of the rotation speed and the acceleration estimator. The proposed
method requires to estimate the rotation speed in order to change the operation mode from the (i) the
deceleration mode to (ii) the stopping mode. The rotation speed is estimated from the back EMF under(ii) the deceleration mode with the free-run mode. The electric angle r of the motor is given by (1).
 v 
 r = tan -1  -   ............................................................ (1) vb 
where, v is the -axis voltage, v is the -axis voltage. The rotation speed is given by differentiation of
the electric angle from (1). The acceleration is estimated from the second derivative of the phasecalculated by (1). Note that the accuracy of the acceleration estimator is deteriorated due to the detection
noise. Thus, this method uses the filter that has derivative characteristics under the rated frequency andcut off characteristics above the rated frequency.
V/f control withstabilization controlvu*

vg*= 0

wre*

dq/3f

vd*

Vf

3f/dq

+
-



1/s

Carrier

Kdamp

Switchingpattern selector

+
-

vv*
vw*

+
iu
iv
iw

PWM
generator

+
-

Sup
Sun
Svp
Svn
Swp
Swn

id
3f/2f

i

x2 + y 2ivui
Current
controler

r

vv

Speed
estimator

vw

wr

mode
selector

Flg_short

Flg_hysteresis
Flg_stop

Fig.7. Control brock of the proposed method.
vu

vv

v

3f/

v

vw

-1

*
/

tan-1

r

wr
swac2rsw
s2 + 2wc s + wc2
s +w

Fig.8. Block diagram of the speed and acceleration estimator.
.

The proposed method switches operation mode to (ii) the stopping mode at TDC in order to stop the
motor during the suction process. Therefore, it is necessary to the estimate TDC during (i) the
deceleration mode.
Figure 9 shows the control flowchart of the proposed method. The operation mode is switched in theorder of (i) the deceleration mode with the free-run method, and (ii) the stopping mode with the shortcircuit braking.
Figure 10 shows the phase, the rotation speed, and the acceleration waveform during (i) the
deceleration mode using the free-run method. As shown in figure 10, TDC is the point when theacceleration ar becomes the small value after the rotation speed is sharply reduced due to the load torque.

Current control method using free-run mode and short-circuit braking
Figure 11 shows the amplitude of the current vector with the hysteresis current control under (ii) the
stopping mode. The short-circuit braking causes an overcurrent, which may damage the motor.
Therefore, it is necessary to control the motor current in order to prevent the over current. In (ii) the
stopping mode, the stator current is controlled by switching the short-circuit braking and the gate blockwith the current controller shown as “current controller” in figure 7. The operation mode switches to thegate block, in which all switching device are turn-off, when the current amplitude is more than the upper
START
FLG_STOP = 1
YESCalculating r，wr，arNOarar_maxYES

ar_maxarr - r_max

2pr_max

NO

r
NO
NO

wr wthYES-0.1 r 0.1
YES
FLG_hysterisis 1iith_upperi

ith_under
i

0.1

END

NO
(i) deceleration modeNO
FLG_short

YES

0

NO
FLG_short 1
YES
NO
YES
(ii) stopping mode(a) Short-circuit braking(b) Free-run
t [s]

t [s]

Estimated
TDC

Fig.10. Phase, rotation speed, andacceleration waveform.

t [s]

t [s]

Amplitude ofcurrent vector : i [A]Threshold : wth

FLG_shortPhase Acceleration Rotation speed
Flg_short : r [rad] : ar [m/s2]: wr [rps]Fig.9. The control flowchart of the proposed method.

Upper limit
Lower limitt(a)(b) (a) (b)(a)

Fig.11. Amplitude of the current vector
under the (iii) stopping modetthreshold. On the other hand, all lower switches of the inverter turn on when the current amplitude isless than the lower threshold. The stator current decreases as the rotation speed decreases because thecurrent depends on the back EMF during the short-circuit braking.

Experimental result with proposed method
This experiment evaluates the vibration with the proposed stopping method. The experimental
conditions are same as the experiment using the free-run method. When the threshold value wth whichis threshold value in order to change the operation mode to (ii) the stopping mode is low, the rotor
bounce is happened during (i) the deceleration mode. Thus, in order to avoid the rotor bounce during
the (i) the deceleration mode, the threshold value is set to 15 r/s, which means the 20% of the rated
rotation speed. The upper limit of the hysteresis control is 1 A, which means the 20% of thedemagnetizing current. In addition, the lower limit is 0.9 A in order to set the current ripple rate to 10%.
Figure 12 shows the waveforms of the estimated rotation speed and the estimated acceleration at theswitch point to (ii) the stopping mode from (i) the deceleration mode. Note that the phase, the rotation
speed, and the acceleration cannot be estimated during the short-circuit braking because EMF is notdetected. As shown in the figure 11, the proposed method detects TDC and switches to the short-circuit
braking at TDC.
Figure 13 shows the current waveform of the motor during (ii) the stopping mode. As shown in figure13(a), the peak value of the motor current is approximately 1.9 A when the current control is not enabled.
On the other hand, the peak value of the motor current is suppressed to less than 1 A by the current
control as shown in figure 13(b). Therefore, the proposed prevent the damage of the motor due to theshort-circuit braking.
rotation speed(10 rps/div)

20 ms/div
Short-cicuit
braking

Acceleration (420 m/s2/div)

Phase (3.14 rad/div)

FLG_hysterisis

Fig. 12. Output waveforms of rotation speed and acceleration estimator.

Amplitude of current
vector : i (0.4 A/div)
Free-run

Peak value isabout 1.9 A

Short-circuit braking

Peak value isless than 1 A

Amplitude of current
vector : i (0.4 A/div)
Free-run

Short-circuit braking
20 ms/div

20 ms/div(a) Without hysteresis current control.
(b) With hysteresis current control.
Fig.13. Motor current waveform in the (iii) stopping mode.
Free-run Short-circuit

200 ms/div

Free-runbrakingrotation speed(10 rps/div)

Vibration

U phase current(1 A/div)

rotation speed(10 rps/div)
U phase current(1 A/div)

V phase current (1 A/div)

V phase current (1 A/div)

Acceleration sensor
output (10 m/s2)

Short-circuit
braking

40 ms/div

Threshold value : wth

Acceleration sensor output (10 m/s 2)(a) Estimated speed and acceleration sensor output. (b) Enlarged view of the waveform at switching point.
Fig.14. Deceleration operation waveforms with the proposed method when the motor stops during
the suction process.

Figure 14 shows the estimated rotation speed, the waveform of the U and V phase current, and theoutput waveform of the acceleration sensor with the proposed stopping method. Figure 14(b) shows the
waveforms at around the changing point from (i) the deceleration mode to (ii) the stopping mode. As
shown in figure 14(a), The rotation speed was decreased until less than the threshold value by (i) the
deceleration mode. After that, the motor stopped during the suction process by changing to (ii) the
stopping mode at TDC. As shown in figure 14(a), the proposed method reduced the vibration at the
motor stop compared to the conventional method using the free-run mode shown in figure 4.
Figure 15 shows the estimated rotation speed, the waveform of U and V phase current, and the output
waveform of the acceleration sensor when the operation mode is changed to (ii) the stopping mode at
BDC. When operation mode switches to (ii) the stopping mode at BDC, the motor stops during thecompression process, which generates the large torque. As shown in figure 15, the large vibration occurs
compared to figure 14. This result indicates that the large torque due to the compression leads to thevibration. Thus, it is necessary to stop the motor during the suction process in order to reduce thevibration.
Figure 16 shows the amplitude of the vibration when the conventional and the proposed stopping
method are applied. As shown in figure 15, the proposed method reduced the average amplitude of thevibration by 67% compared to that of the conventional method using the free-run mode. In the free-run
mode, the amplitude of the vibration had large variability because the free-run mode cannot control the
stopping position of the motor. On the other hand, the proposed method controls the stopping position.
Thus, the variability of the amplitude of the vibration when the proposed method was applied was small.
Free-run Short-circuit braking

rotation speed(10 rps/div)

200 ms/div

V phase current (1 A/div)

Free-run

Short-circuit 40 ms/div
brakingrotation speed(10 rps/div)
U phase current(1 A/div)

V phase current (1 A/div)

U phase current(1 A/div)
Acceleration sensor
output (10 m/s2)

Vibration

Acceleration sensor output (10 m/s2)(a) Estimated speed and acceleration sensor output. (b) Enlarged view of the waveform at switching point.
Fig.15. Deceleration operation waveforms when the motor stops during

Frequency [%]

6060
4040

Measurement : 40 times

8080

Average value of
amplitude of vibration :13.6 m/s2

60
60

Average value of
amplitude of vibration :4.4 m/s2

40
40

2020

20
20

0

2

4

8 10 12 14 16
6
Amplitude of vibration [m/s2]

18

20

0

0

2

4

6
8 10 12 14 16
Amplitude of vibration [m/s2]

18(a) Conventional method (free-run)(b) Proposed method
Fig.16. Amplitude of vibration with conventional and proposed stopping method.
Amplitude of vibration [m/s2]00

Measurement : 40 times

Frequency [%]

8080

2020

wth= 20 rps

Measurement : 10 times
wth= 15 rps

1515
1010
55

Amplitude ofvibration : small
Amplitude ofvibration : large

00
-60
60
120
180
240
300
00
60
120
180
240
Mechanical angle at change to short-circuit braking [deg]Fig.17. Peak value of vibration when operation mode switched to (ii) stopping modeat each mechanical angle.

20

Figure 17 shows the amplitude of the vibration when the operation mode is switched to (ii) the stopping
mode at each mechanical angle. when the threshold value of the rotation speed was 15 r/s, the rotor
bounce occurred at the mechanical angle of 300 to 350 degree. Thus, the threshold value was changed
to 20 r/s from 15 r/s, in this period. As shown in figure 17, the proposed method reduced the amplitudeof the vibration by 67% or more compare to the conventional method in the condition of the switching
operation mode to (ii) the stopping mode at the mechanical angle of 0 to 60 degree. Therefore, theproposed method reduces the vibration at stop even when the estimated mechanical angle has error of
approximately 60 degree due to delay of detection of voltage and detection noise.
Figure 18 shows the amplitude of the vibration at the different pressure conditions. As shown in figure
18, in the conventional method using the free-run mode, the amplitude of the vibration increased when
the pressure inside the cylinder was high because the amplitude of the load torque was large. On theother hand, the proposed method reduced the vibration by 58% or more compare to the conventional
method in all four pressure conditions.
Table 2 shows the amplitude of the vibration and the reduction ration of the vibration compare to theconventional method. As shown in the table 2, the proposed method achieved the reduction of thevibration by 71 % at Pd = 0.65 MPa and Ps = 0.05 MPa.

Conclusion
This paper proposed the low-vibration stopping method, which changes (i) the deceleration mode using
the free-run mode and (ii) the stopping mode using the short-circuit braking. The proposed method
reduced the vibration by stopping the motor during the suction process of the compressor because thecompressor generates the lower torque in this process. This method achieved the stopping the motor
during the suction process by switching the operation mode to (ii) the stopping mode from (i) the
deceleration mode at TDC. As the experimental result, the proposed method reduced the amplitude of
the vibration by 67% compare to that of the conventional method using the free-run mode. In addition,
the proposed method reduced the vibration by 58% or more compare to free-run mode in all four
considered pressure conditions.

References[1] B. Hu; Z. Huang: “Linear Quadratic Extended State Observer based Load Torque Compensation for PMSM ina Single Rotor Compressor”, 2019 22nd International Conference on Electrical Machines and Systems (ICEMS),
Harbin, China, 2019

Amplitude of vibration [m/s2]

20
20

16

16

12
12

Measurement : 10 times
Condition1 : (0.05, 0.38)
Condition2 : (0.075, 0.30)
Condition3 : (0.075, 0.60)
Condition4: (0.05, 0.65)

215.0 m/s
9.5 m/s2

88
3.9 m/s2

44
00

Conventional
1 method(Free-run)

4.3 m/s2

Proposed2 method

Fig.18. Peak value of vibration in terms of pressure conditions.
Table 2. Comparison results of vibration at stop.
1

Average value [m/s2]
Reduction
Free-run Proposed method rate [%]
3.9
58.9
9.5

2
Pressurecondition [MPa] 3

10.7

4.1

61.7

14.7

4.2

71.4

4

15.1

4.3

71.5

[2] K. Lee, S. Park and S. Jeong, "A Seamless Transition Control of Sensorless PMSM Compressor Drives for
Improving Efficiency Based on a Dual-Mode Operation," in IEEE Transactions on Power Electronics, vol. 30, no.
3, pp. 1446-1456, March 2015
[3] X. Song, B. Han, S. Zheng and S. Chen, "A Novel Sensorless Rotor Position Detection Method for High-Speed
Surface PM Motors in a Wide Speed Range," in IEEE Transactions on Power Electronics, vol. 33, no. 8, pp. 70837093, Aug. 2018[4] K. Lee, J. Hong, S. B. Lee and S. Lee, "Quality Assurance Testing for Magnetization Quality Assessment of
BLDC Motors Used in Compressors," in IEEE Transactions on Industry Applications, vol. 46, no. 6, pp. 24522458, Nov.-Dec. 2010[5] K. Lee, S. Park and S. Jeong, "A Seamless Transition Control of Sensorless PMSM Compressor Drives for
Improving Efficiency Based on a Dual-Mode Operation," in IEEE Transactions on Power Electronics, vol. 30, no.
3, pp. 1446-1456, March 2015[6] G. Zhang, G. Wang and D. Xu, "Saliency-based position sensorless control methods for PMSM drives - A
review," in Chinese Journal of Electrical Engineering, vol. 3, no. 2, pp. 14-23, September 2017[7] Toshihiko Noguchi, "Trends of permanent-magnet synchronous machine drives," IEEJ Transaction onelectrical and electronic engineering, Vol.2, No.2, pp.125-142, Feb. 2007
[8] Shigeo Morimoto, "Trend of permanent magnet synchronous machines," IEEJ Transaction on electrical andelectronic engineering, Vol.2, No.2, pp.101-108, march. 2007
[9] Yukio Honda, Yoji Takeda, "Technical evolution of permanent magnet synchronous motors for home
appliances," IEEJ Transaction on electrical and electronic engineering, Vol.2, No.2, pp.118-124, march. 2007[10] S. Suthep, W. Yankai, I. Yuuma, M. Ishida, K. Yubai and S. Komada: “Fram- Anti-Vibration Control for
Sensorless IPMSM-Driven Applications”, 2016 42nd Annual Conference of the IEEE Industrial Electronics
Society (IECON), Florence, Italy, 2016[11] P. Mattavelli, L. Tubiana, and M. Zigliotto, “Torque-Ripple Reduction in PM Synchronous Motor Drives
Using Repetitive Current Control”, IEEE Transaction on Power electronics, Vol.20, No.6, pp.1423-1431, Nov.
2005[12] Tinghsu Su, S. Hattori, M. Ishida and T. Hori, "Suppression control method for torque vibration of AC motor
utilizing repetitive controller with Fourier transform," in IEEE Transactions on Industry Applications, vol. 38, no.
5, pp. 1316-1325, Sept.-Oct. 2002
[13] L. Qu, W. Qiao and L. Qu, "An Enhanced Linear Active Disturbance Rejection Rotor Position Sensorless
Control for Permanent Magnet Synchronous Motors," in IEEE Transactions on Power Electronics, vol. 35, no. 6,
pp. 6175-6184, June 2020[14] Qiong Wang, Shuanghong Wang, Chuanhai Chen, “Review of sensorless control techniques for PMSM
drives”, IEEJ Transaction on electrical and electronic engineering, Vol.14, pp.1543-1552, July. 2019[15] X. Song, J. Fang, B. Han and S. Zheng, "Adaptive Compensation Method for High-Speed Surface PMSM
Sensorless Drives of EMF-Based Position Estimation Error," in IEEE Transactions on Power Electronics, vol. 31,
no. 2, pp. 1438-1449, Feb. 2016.
[16] Y. Niimi et al., “Vehicle air conditioner with compressor noise reduction control,” U.S. Patent 5 950 440,
Sep. 14, 1999.