JOURNAL
VOLTAGE FLICKER EFFECT ON THE WORK INDUCTION MOTOR
MECHANICAL SPEED + MORTOR INDUCTION
Abstract
VOLTAGE FLICKER EFFECT ON THE WORK INDUCTION MOTOR
MECHANICAL SPEED + MORTOR INDUCTION
Abstract
Voltage Dips is one of the quality parameters of electricity so becoming costumer attention. because it can bring adverse impact on the operation of the electrical installation.
Voltage flicker disturbance is one form of the disorder that is considered the most frequent cause losses due to disruption of production processes in industry. Voltage flicker interference is a problem which is effectively at the side of the installation user and supplier of power. Interference voltage flicker very short time (0.1 seconds). In this study discussed the blink of an induction motor voltage at speed, especially on the mechanics. This analysis was based on the results of research on the research operation of induction motors.
Voltage flicker disturbance is one form of the disorder that is considered the most frequent cause losses due to disruption of production processes in industry. Voltage flicker interference is a problem which is effectively at the side of the installation user and supplier of power. Interference voltage flicker very short time (0.1 seconds). In this study discussed the blink of an induction motor voltage at speed, especially on the mechanics. This analysis was based on the results of research on the research operation of induction motors.
Keywords: voltage flicker, voltage flicker disturbances, mechanical speed.
I. INTERODUCTION
1.1 Background
Power quality can affect the production of an industrial process that requires special requirements on the quality of electric power, which is directly or indirectly a very prominent regulator means to improve productivity, product quality, and competitiveness of production. If the power quality does not meet expectations, and production operations can disturbed. This is often a problem for the power companies and consumers.
Power companies are obliged to provide services and the supply of electricity with good quality. Inaccuracy in the power purchase agreement between the electricity companies and consumers are often raises difficult problems that completely resolved.
Consumers who feel harmed by the power quality which does not meet the requirements of the machinery of production, appealed for their losses. The power company can not accept complaints objection granted, because its bad either power quality can be caused from two sides: the electric company or the consumer.
In general, if the quality of electric power comes from the power company, an attempt to reach a solution is to provide quality supply that is expected, but these efforts are often not met expectations, so in this case needs to be done by using Permanent Power Supply Systems (UPS), which would require a significant financial cost.
One of the parameters of power quality is the quality of perceived stress in general consumer terminated (Pakpahan., 2000), the quality of the expected electricity consumer are:
- The minimum power supply Diskontuinitas
- Voltage strict regulation
- Harmonization of voltage as low as possible
- Voltage fluctuations without effect voltage terminal.
Disturbances in the transmission line or feeder adjacent to feeder that supplies industrial installations can result in flicker voltage and phase imbalance resource system of industrial installations. The interference burdens sensitive to disturbances in the installation may be automatically regardless of the network, caused by the work of the automatic system or existing protective equipment.
According to the journal “IMPROVEMENT OF VOLTAGE QUALITY BY USING DYNAMIC VOLTAGE RESTORER (DVR)” Power distribution systems, ideally, should provide electricity to customers continuously with voltage level and smooth sinusioda fixed frequency. However, in practice there are many power system load is not linear, having a significant effect on the quality of the power supply.
Due to this non-linear load, the waveform of the supply becomes purely sinusoidal. It produces power quality problems. Besides the non-linear loads, multiple events on the system (eg: capacitor switching, motor starting) or the presence of interference can also cause power quality problems. Power quality issues are becoming increasingly important to consumers of electric power at all levels of usage. Sensitive equipment and non-linear loads are now becoming commonly used both in the industrial sector and the domestic environment. therefore the awareness of power quality continue to grow in the use of electricity. Disturbances in transmission or distribution line can cause voltage transients, sag or swell in the system. Same thing on the heavy load conditions, a significant voltage drop can occur in the system. Voltage sag can occur at any time with the amplitude range between 10-90% and the duration of the half cycle of up to one minute. On the other side the increase in voltage (swell), defined as the sudden rise in the value of the electrical voltage in the range of 110% -180% amplitude with a duration of 10 ms to 1 minute. Sag and Swell can cause sensitive equipment become fail to operate or stop. The impact could be the start of production berhentiya to damage the equipment.
1.2 Problem Formulation
Voltage Dips and termination of the instantaneous power becomes the most important issue of power quality can affect industrial and commercial customers in wide. event is usually associated with disorders something to the power supply system. Termination can occur when gagguan actually be at the customer supply circuit. Voltage Dips most of more common because it can be associated with disturbances away from the customer. Voltage Dips is one of the power quality parameters of concern to consumers, because it can bring harm to the operation of the equipment electricity.
Voltage Dips, although the course of just a moment, but the impact can result in that particular consumer disruption. the majority of consumers, especially consumers who use equipment that is sensitive to voltage, this disorder can lead to the equipment does not function normally or even stop altogether. Voltage-sensitive equipment, such as electronic instrumentation, computers, electric motors, lighting can be disrupted due to low voltage quality, one reason is the interference voltage flicker. Mansoor et al, (1997), suggests disturbance and three-phase voltage flicker is relatively rare (usually less than 20%), but the three-phase unexpected disruptions will result in the worst condition of stability (Das, 1990)
Voltage flicker analysis focuses on understanding the characteristics of voltage flicker, information characteristics caused possibility that describes the voltage flicker sensitivity load load in this case induction motor.
Voltage flicker analysis focuses on understanding the characteristics of voltage flicker, information characteristics caused possibility that describes the voltage flicker sensitivity load load in this case induction motor.
Based on the things that have been in the background described above, the formulation of the problem in this study are:
- What magnitude mechanical speed when the percentage magnitude of voltage flicker enlarged.
- how much power the mechanical speed if extended speech disorders.
1.3 The purpose of the study
Determine the magnitude of the mechanical speed during a pulsating voltage, both when the disturbance and recovery time lasts. The magnitude of the voltage flicker to the percentage of 40%, 60%, and 80% of the normal voltage motors and interference detection 0.2 and 0.8 seconds.
1.4 Theoritical review
There are several methods used to reduce sag and swell. The use of a custom Power devices (CPD) is considered as the most efficient method. There are many types of CPD, among others, active power filter / Active Power Filters (APF), the power storage system batteries / Battery Energy Storage System (BESS), Distribution Static synchronous COMpensators (DSTATCOM), Capacitors Series / Distribution Series Capacitors (DSC), Restorer voltage electric dynamic / dynamic Voltage Restorer (DVR), Uninterruptible Power Supplies (UPS) and others.
Each of CPD devices has advantages and limitations The type of equipment that are considered most effective is the dynamic power supply voltage restorer (DVR). There are several reasons why the DVR is preferred over other equipment. Some of these reasons are presented as follows. SVC devices earlier than the DVR, but DVR is preferred because SVC does not have the ability to control the flow of active power. Another reason is DVR cheaper than UPS.
UPS is not only expensive, but also requires intensive maintenance because the battery leak and has a certain life span, so it must be replaced every five years. Other reasons are the DVR has a higher capacity and cheaper than equipment smash. In addition, the size of the DVR smaller and cheaper than the DSTATCOM.
Based these reasons, it is not surprising when the DVR is widely considered as an effective power tool in mitigating voltage sag. In addition, besides compensating sag and swell, DVR also has additional features such as harmonic filters and power factor correction. Compared to other devices, DVRs provide the best economic solution for the size and capabilities.
According to the standard IEEE 1159-1995, IEEE Recommended Practice for Monitoring Electric Power Quality, the definition of sag is the decline in the value of the rms voltage or current at power frequency for duration of 0.5 cycles (0,01detik) to 1 minute. And the range of changes from 0.1 to 0.9 pu at a price the amount of voltage or current rms. This led to the release (trip) equipment that is sensitive to voltage changes.
Figure 1. Voltage Sag [9]
Figure 2 shows the type of voltage sags caused by disturbances of the phase to ground at another feeder of the same substasion. Approximately 80% voltage sag will appear for three cycles to the circuit breaker substasion able to decide fault current. Time termination time (clearing times) ranges from 3-30 cycles depending on the type of major fault current and overcurrent protection.
Figure 2. Voltage Sag due to interference of the phase to ground [9]
II. THEORY
2.1 Mechanical speed
Figure 1.1 Speed motor mechanics to blink voltage 40%, duration 0.2 seconds
Mechanical speed of the motor in normal conditions is 77.75 rad / sec, but the mechanical speed is decreased when the speed of voltage flicker disturbances. Speed down to 76.286 rad / sec. When the disorder is lost, then the mechanical speed of the motor back riding until a normal condition within 0.685 seconds So be seen from these results that in the event of disruption, decreased motor rotation, but when the conduction disturbance is lost, the motor speed is not directly normal again , but require a recovery time so that the motor rotates back at normal speed.
Figure 1.2 mechanical speed for voltage flicker disturbances 40%, duration of 0.8 seconds.
So it appears that if the interruption duration was extended from 0.2 seconds to 0.8 seconds, it will result in a decrease in the mechanical speed of the motor becomes larger. Mechanical speed fell to 73.492 rad / sec to 0.8 sec duration of the interruption. Meanwhile for a duration of 0.2 seconds, the disruption mechanical speed dropped to 76.286 rad / sec.
Figure 1.3-b Va voltage to the voltage flicker 60%, duration 0,8 detik
Figure 1.3, interference occurs at t = 10 seconds to 10.8 seconds, and the magnitude of the voltage flicker magnitude is 1980 volts (60% of normal voltage), after the supply voltage is normal again.
Figure 4.20 electromagnetic torque for 60% voltage flicker duration of 0.8 seconds
Figure 4.20 shows the characteristics of the electromagnetic torque to the pulsating voltage of 60% with a duration of 0.8 seconds. At the time of normal conditions the electromagnetic torque constant value of 0.79 x 104 Nm which occurs at t = 10 seconds, after which the electromagnetic torque experienced loss. When the disturbance ends and normal stress condition back, re-experiencing the electromagnetic torque peak torque at t = 10.8 seconds magnitude is 2,373 x 104 Nm, the recovery time for 0.595 seconds. It is seen that if the duration of the interruption is extended from 0.2 to 0.8 seconds, while maintaining the voltage flicker magnetude 60%, then the maximum amount of torque when the initial disturbance is fixed, but when the interruption ends or when the initial recovery, electromagnetic torque peak for interference duration greater than 0.8 seconds 0.2 seconds duration disturbance is 2.12 x 104 Nm.
Figure 4.22. Mechanical speed for 60% voltage flicker duration of 0.8 seconds
Figure 4.22. Mechanical speed for 60% voltage flicker duration of 0.8 seconds
Mechanical characteristics of the motor speed to 60% voltage flicker disturbances in 0.8 seconds duration are shown in Figure 4:22. Mechanical speed decreased speed at saan disturbance occurs. The speed decreases until it reaches 72.026 rad / sec. After missing disorders and the motor supply voltage returns to normal, the mechanical speed of the motor back up and reach its normal condition within 0.501 seconds. So it is seen that by extending the duration of the interruption of 0.2 seconds to 0.8 seconds, then decrease the mechanical speed becomes larger.
Graph 4.25. Torque elektrimagnetik for 80% voltage flicker duration of 0.2 seconds
When normal conditions, the electromagnetic torque is constant 0,79x104Nm, but in the event of voltage flicker at t = 10 seconds, the electromagnetic torque experienced fluktusasi during the transition period. Teradi peak torque at the beginning of disorder is 1,542 x104Nm. After the voltage flicker disturbances ended, torque astray back ride to reach 1,738 x104Nm, and then declined to fluctuate to return to its normal state within 0.488 detij. The results showed that the greater the voltage flicker presentasion magnetude of normal voltage, the smaller the peak torque during the transition took place, both at the time of interruption or at the time of recovery, it is shown from the results of the study as follows: peak torque disturbance when each is -3.130 x1044 Nm (40%); X1044 Nm 2,105 (60%); x104 Nm and 1,542 (80%), while peak torque at the time of recovery is x104 Nm 2.24 (40%), 2,120 x104Nm (60%) and 1,738 x104 Nm (80%).
Figure 4:27 mechanical speed for voltage flicker 80%, duration 0.2 seconds
Characteristics mechanical speed at the time of interruption is shown in Figure 4:27 Disorders arising voltage flicker at t = 10 seconds resulted in mechanical speed decreases until it reaches 77.3915 rad / sec. After the interruption ends, the speed slowly starting to climb back up to its normal condition at the speed reached 77.75 rad / sec. The results of the study showed that when the magnitude of the voltage flicker is enlarged, the mechanical speed reduction becomes smaller, it is proved the following results: a decrease in the maximum mechanical speed is, 76.286 rad / sec (40%), 76.916 rad / sec (60%) , and 7.395 rad / sec (80%) with large states megnetude presented a voltage flicker.
Description
|
Percentage Voltage Dips
(%) |
Duration Disorders
(Seconds) |
Duration Recovery
(Sec) |
Value
Maximum Down |
amount
reduction |
Mechanical speed (rad / sec)
|
40
|
0,2
|
0,685
|
762,86
|
1,464
|
0,8
|
0,737
|
73, 492
|
4,258
| ||
60
|
0,2
|
0,479
|
76,916
|
0,834
| |
0,8
|
0,501
|
76,026
|
1,724
| ||
80
|
0,2
|
0,413
|
77,390
|
0,360
| |
0,8
|
0,435
|
77,280
|
0,470
|
TABLE 2 The magnitude of the decline at the time of disturbance and recovery of mechanical speed.
It should be noted that the peak value of the voltage recovery time is greater than at the time of lengthening the duration of the interruption will only lead to increased interference peak value of the electromagnetic torque at the beginning of the peak alone, (when the interruption ends while the peak value occurring at the time of interruption remain, as a result more cause long interruption occurs will the length of the recovery duration required by the motor.
III. CONCLUSION
3.1. Conclusion
Voltage flicker disturbances will cause mechanical speed decreases until the disturbance is over, after the mechanical speed of the ride back to normal condition is reached. If the voltage flicker greater percentage (the smaller the voltage drop) then the smaller the mechanical speed reduction, thereby further recovery duration Short. if extended interruption duration, the greater the magnitude of the decline, as a result of extended duration of recovery.
- The mechanical speed dropped to 76.286 rad / sec, or the magnitude of the decline 1.464 rad / sec with a duration of 0.685 seconds recovery.
- mechanical speed dropped to 73.494 rad / sec, or the magnitude of decrease in 4,258 rad / sec, with a duration of 0.737 seconds recovery.
- mechanical speed dropped to 76.916 rad / sec, or the magnitude of the decline 0.834 rad / sec, with a duration of 0.479 seconds recovery.
- mechanical speed dropped to 76.026 rad / sec, or the magnitude of decrease in 1,724 rad / sec with a duration of 0.501 seconds recovery.
- mechanical speed dropped to 77.390 rad / sec, or the magnitude of the decline 0.360 rad / sec with a duration of 0.413 seconds recovery.
- mechanical speed dropped to 77.280 rad / sec, or the magnitude of decrease in 0,470 rad / sec with a duration of 435 seconds of recovery.
3.2 Suggestions
Today equipment control electric motors mostly use power electronics-based control systems are very sensitive to changes in the amount of input. The existence of short duration voltage flicker, will be felt by the control equipment, as a result, the control system becomes disrupted and It is going to affect the performance of the motor. Additional compensation equipment such as DVR, SCV, and so is designed to overcome the interference voltage flicker is that if there is disruption of motor performance is no longer affected. This study has shown that the presence of voltage flicker disturbances have caused fluctuating currents are, therefore this research can be developed further by examining the effect of the use of compensation DVR, SCV and so on to work when the induction motor voltage flicker problems arise.
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journal “IMPROVEMENT OF VOLTAGE QUALITY BY USING DYNAMIC VOLTAGE RESTORER (DVR)” by Winarso
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