Electrical Engineering: Capacitor Comparison and Analysis

This report delves into the comparative analysis of run capacitors utilized in single-phase motors and filter capacitors employed in Uninterruptible Power Supply (UPS) systems. It elucidates the fundamental distinctions between these capacitor types, focusing on their operational characteristics and intended applications. The report outlines the specific functions of run capacitors in single-phase motors, emphasizing their role in providing the necessary phase shift for motor operation. Conversely, it explores the functionality of filter capacitors within UPS systems, highlighting their importance in smoothing power inconsistencies and improving power quality. The report provides technical specifications, performance graphs, and data sheets for both types of capacitors. It addresses the question of why a 5uF run capacitor is unsuitable for input and output filtering in a UPS. The report also provides application examples to illustrate the practical use of each capacitor type. This comprehensive analysis aims to provide a detailed understanding of the differences and applications of run capacitors and filter capacitors within their respective electrical systems, making it a valuable resource for electrical engineering students and professionals.

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Difference between run capacitor used in single phase motor and capacitor for filtering
used in the UPS
A capacitor generally defines a device used in the storage of energy. It defines a system through
which energy is stored to be released over a given period of time or suddenly. The capacitance or
otherwise energy of an electric capacitor is often measured in microfarads. A run capacitor
adopts the charge within the dielectric in boosting the current that offers power to the motor. It is
adopted in keeping a charge. In AC units, there exist dual run capacitors in which one of
capacitors offer power to fan motor even as the other sends power to compressor. Run capacitors
often taken measurements at about 7-9 microfarads. The value of even the rating of run capacitor
has to be of high accuracy [1]. In case the value tends to be very high, the phase shift would be
less than ideal and the winding current would be too high. Suppose the capacitor value otherwise
rating tends to be too low, the phase shift would be higher with the winding current being too
low. In cases where the capacitors are not idea, the motor is likely to overheat and the actual
torque would not be sufficient in driving the current.
A few single phase AC induction structures utilize motor run capacitors, which are left
associated with the auxiliary coil considerably after the start capacitor is detached by the
centrifugal switch. Such plans work by making rotating magnetic field. Motor run capacitors are
intended for persistent obligation, and stay fueled at whatever point the motor is controlled,
which is reason electrolytic capacitors are dodged, and low-misfortune polymer capacitors are
utilized [6]. The capacitance estimation of rotor capacitors is normally lower than the
capacitance of start capacitors, and is freqm can bring about a lopsided attractive field, which can
be seen as lopsided motor revolution motor, execution drops and expanded vitality utilization,
just as extra warming, which can make motor overheat.

Motor run capacitors are utilized in single-stage AC enlistment motors. Such motors are utilized
at whatever point a solitary stage control supply is more commonsense than a three-stage control
supply, for example, in local apparatuses[2]. They are not as productive as three-stage AC
acceptance motors, be that as it may. Truth be told, single-stage AC motor are 2 to multiple times
less proficient than three-stage AC motors, which is reason they are utilized distinctly for less
incredible motors. Run of mill applications which use turn over and run motor capacitors
incorporate power apparatuses, clothes washers, tumble dryers, dishwashers, vacuum cleaners,
air conditioners as well as compressors.
Figure 1: Changing run capacitor speeds in single phase motors [2]

Figure 2: Run capacitor data [2]
Figure 3: Specifications [2]
The stock of capacitors inside an UPS shifts enormously contingent upon the greatness of
activity to be done, that is, the kVA rating of unit [3]. To place this in context, a run of mill

individual PC contains around 50 capacitors; a 750 kVA three-stage UPS may have several
them. Indeed, even the littlest UPSs use many capacitors.
The hypothetical operational lifetime of a capacitor is a numerical capacity of evaluated voltage,
applied voltage, current through the capacitor, surrounding temperature and warm obstruction.
Practically speaking, you can evaluate expected assistance life in light of maker's evaluated life
expectancy and the working temperature of gadget. The more smoking the working temperature,
the shorter the life. The wide scope of various forces implies that UPS items are part up into
different sections: little single-stage UPS frameworks for the most part with powers up to 12
kVA, trailed by 3-stage mid and high power goes up to 50 kVA, 200 kVA and even over 200
kVA [4].
At the point when utilized as channels, control capacitors will smooth any inconsistencies in the
power organize and help to improve control quality and unwavering quality. A run of mill UPS
of mid control extend utilizes a normal of ten power capacitors for each framework for sifting.
Aluminum electrolytic capacitors work as DC interface capacitors. EPCOS offers these parts in
various variations, for example with screw, snap-in, 4-pin snapin or patch pin terminals. The
fitting film capacitors for the info and yield channels of UPS frameworks are the PhaseCap
MKK, MKP or even MFP arrangement [5].

Figure 4: overview of capacitors used in UPS [3]
Figure 5: Power capacitors [3]

Table 1: Technical data [3]
Figure 6: Dimensional drawings [3]
Figure 7: Filter capacitor performance in UPS [5]
Can use 5uf running capacitor into UPS to filter input and distribution output, why not?
The size of input filter is very significant since it is a factor of the reducing lower order
harmonics to double conversion UPS. The size of the capacitor bank insinuates suppose the
double conversion UPS is loaded lightly, the overall power factor taking into consideration the
UPS or filter combination would most likely be classified as leading. This translates to the

profile for the double conversion appearing to be capacitive to utility or even local generator.
The 5uf running capacitor is thus not usable in UPS to filter input and distribution output as the
size of the capacitance is very low and may not generate any harmonics
References

[1] M. Aamir, K.A. Kalwar and S. Mekhilef, Uninterruptible power supply (ups)
system. Renewable and sustainable energy reviews, 58, pp.1395-1410, 2016
[2] A.K. Adapa and V. John, Active-phase converter for operation of three-phase induction
motors on single-phase grid. IEEE Transactions on Industry Applications, 53(6),
pp.5668-5675, 2017.
[3] Z. Anthony and F. Ismail, Single Phase Induction Motor with 4 Windings Design and
Current Control in Auxiliary Winding. In International Conference of CELSciTech 2019-
Science and Technology track (ICCELST-ST 2019). Atlantis Press, 2019, December.
[4] M.R. De Souza, Whirlpool, Start and control method for a single-phase induction motor,
a start and control system for a single-phase induction motor and an electronic start and
control device applied to a single-phase induction motor. U.S. Patent 9,160,259, 2015.
[5] W.R.N. Santos, E. de Moura Fernandes, E.R.C. da Silva, C.B. Jacobina, A.C. Oliveira
and P.M. Santos, Transformerless single-phase universal active filter with UPS features
and reduced number of electronic power switches. IEEE Transactions on Power
Electronics, 31(6), pp.4111-4120, 2015.
[6] M.B. Shamseh, T. Yoshino and A. Kawamura, Current-Dependent Capacitor Voltage
Control of Parallel Autonomous UPS Systems. IEEE Transactions on Industrial
Electronics, 65(4), pp.2873-2882, 2017.
[7] M. Zanelato, C. Bruning and M.R. De Souza, Whirlpool, Method for starting a single-
phase induction motor, starting device for a single-phase motor and starting system
therefor. U.S. Patent 9,184,678, 2015.