Report on an industrial visit to Platinum Jubilee Jute Mills Ltd., Khulna.

1. Khulna University of Engineering & Technology
Department of Electrical & Electronic Engineering
Project: Industrial Visit to Platinum Jubilee Jute Mills Ltd.
Submitted by:
1603013 – Symon Saroar
1603015 – Al Imran Fahim
1603016 – Arnab Sarkar
1603017 – Maruf Ahsan Rifat
1603018 – Sagar Mutsuddi
1603025 – Naheen Aanan
Submitted to:
1. Dr. Bashudeb Chandra Ghosh
- Professor, Dept. of EEE, KUET
2. Dr. Md. Habibullah
- Assistant Professor, Dept. of EEE, KUET
Wednesday, 19th June, 2019

2. Overview
An industrial visit to “Platinum Jubilee Jute Mills Ltd.”, Khulna was organized by the department
of Electrical and Electronic Engineering of Khulna University of Engineering & Technology on
Saturday, 25th May, 2019. We, A group of 6 students visited the jute mills to interact with the mills
& its procedures for a better understanding of our academic course elements.
Company Profile
Name Platinum Jubilee Jute Mills Ltd.
Address BIDS Road Town, Khalishpur, Khulna.
Year of establishment 1954 (Active since 1958)
Shareholders Bangladesh Jute Mills Corporation (BJMC)
Year of incorporation with BJMC 1972
Area 55.84 Acres
Number of looms Hessian 560 Sacking 315 Carpet Backing
Cloths (CBC)
82
Monthly average production
capacity (in ton)
Hessian 554.50 Sacking 1069.25 Carpet Backing
Cloths (CBC)
165.50
Contact:
Coordinates: 22.861357, 89.548262
Address: Khalishpur, Khulna
Email: platinum_jubilee@yahoo.com
Phone: +880 (41) 760 291
Web: bjmc.gov.bd
Objectives of the visit
The main Objectives of this industrial visit was –
1. To learn the practical process of motors.
2. To learn how a jute mill controls its power supply & operates.
3. To learn practical implementation of EE 3108 – Sessional on Electrical Machine - II &
determine the associativity of this course in real life.
Introduction
Industries widely uses 3 phase AC Motors. Induction motors or asynchronous motors are more
popular than Synchronous motors because of them being self-starting, reliable and more
economical.
Three phase squirrel-cage induction motors are suitable for most industrial loads. As squirrel-cage
motors has a rugged construction and simple design.

3. Three phase slip ring induction motors are less practical as they require external resistors to gain
a high starting torque.
Single phase induction motors are used extensively for smaller loads.
As per our visit to “Platinum Jubilee Jute mills” all of the running motors were squirrel-cage
induction motors. Slip ring motors are used where there is an application of rotating platform (or
need a strong jumpstart).
The Jutes goes through a long journey before turning into production.
The Jute mill works at following flow –
The mills do their power distribution on their own.
They follow common structure for power distribution with HT (High Tension) Panels, LT (Low
Tension) panels and ACBs (Air Circuit Breaker).
Two Step down transformers are used to convert the grid voltage then supplied to all the motors
in the factory.
Raw Jute Selection
Softening
Carding
Drawing
Spinning
Winding
Weaving
Calendaring
Cutting
Sewing
Pressing
Storing

4. Power Distribution structure of Platinum jubilee Jute mils –
Power Distribution
Electric power is supplied from some private utilities or public utilities or in some cases both to a
industry. These supplied voltage ranges between 11kV, 33kV, 66kV or 132kV. It is necessary to use a
step-down transformer to convert supplied >= 11kV voltage to ~440 V for using them to run motors.
This 440 V system is called Low Tension System.
Then power from LT (low tension) panel is supplied into the factory to various panels through
switches, circuit breakers, fuses and other protective equipment.
Also, before the power is supplied to various panel, they go through a Capacitor Bank. A Capacitor
Bank, consisting lot of high capacitors that can help counter-act all lagging current due to all the loads
of the industry. This will help to improve the power factor hence more economy.
HT Panel
LT Panel
Sub LT Panel
SDB
(Sub
Distribution
Board)
PDB
(Power
Distribution
Board)
Grid (11 KV),
Transformers
(Step down)
3 phases
440V, 50Hz
APFC
(Automatic Power Factor
Correction Panel)

5. Description of different aspects of power distribution:
Low Tension Panel (LT) :- The switchgear arrangement on each distribution side is housed in
metal-enclosed structures called LT panels. These LT panels are responsible for distributing the to
various sub LT panels after receiving it from the transformer.
Air Circuit Breaker (ACB) :- It makes or breaks the Circuit either manually or remotely
controlled during normal operating condition and break the circuit during fault condition
automatically.
Bus Bar :- Bus bars are made with highly conductive copper, in some cases, aluminum to reduce
cost. Bus Bars collect the supply from transformer terminal to various elements in the panel such as
ACBs, capacitor bank, switch gear and other connected loads.
Capacitor Bank or Automatic Power Factor Correction Panel (APFC) :- It is a separate
panel that consisting of bus bars, MCCBs, tuned reactors, capacitor
units, contactors, metering equipment and cables. The capacitors
and reactors are type of indoor air-cooled units. The capacitor
banks are connected across the supply to improve power factor of
the system. The capacitors are switched automatically through
programmable devices (or manually if needed) depending on the
amount of reactive power to be compensated. In the mill these was
a 870 KVAR capacitor banks that can well enough improve the
power factor up to 0.99.
Metering and Indication :- Voltmeters, ammeter and power factor meters in LT panel indicate
various parameters and these are also protected with MCBs. On all LT and sub-LT panels indicating
lamps are provided for each phase to monitor live condition.
Sub-Distribution Boards (SDB) :- SDBs consist of bus bars that receives power from either
sub LTs or main LT panels and distributes it to various heavy machineries and PDBs.
Power Distribution Boards (PDB) :- These consists of short circuit as well as overload
protection. PDBs distributes power to various machines and equipment. PDBs are also fitted with
different protective relays.

6. Installed Load
Important load of the industry is the motors. Almost all of the motors are induction motors
running for various purposes (other than ceiling fans which are fan motors).
Induction motors or asynchronous motors are of two types: i) Squirrel Cage ii) Slip Ring
Squirrel Cage motors has a rugged body around its winding, easy to maintain and economical
overall. So, the factory used squirrel cage motors for every purpose.
Some of the Heavy loads (high power motors) uses Wye – Delta starter. Because starting current
of an induction motor is almost 6 to 7
times higher than its running current.
The wye-delta starter helps reducing
the starting current. It connects the
motor winding to wye during the start
that makes it so the current can divide
and reduces the voltage across the
winding. After the starting period
when motor is in stable speed the
starter connects it to delta like
before. As The starter reduces voltage
it also reduces the torque (which is
bad). But its okay because most of the
motors do not need high starting
torque.
When we need high starting torque its better to use a slip ring induction motor. As it has high
external resistance to give it a jumpstart.
Most of the task of the mill do not require high load. Machines such as spinning machines,
winding machines, cutting machines etc. uses single phase induction motor. But the pressing
machine has high load. It runs on a three-phase induction motor.
Motors installed for different purpose is given below:
Softening -> Softening machines are used for making the selected jutes soft and pliable. 3
machines of 18 HP running at approximately 720 rpm.
Carding -> Carding machine produce straight fiber and removes dust. 5 machines of 15 HP are
used for this purpose.
Drawing -> There are 26 machines using 5HP each to reduce the width of fibers and making
uniform fibers for storing.

7. Spinning -> The spinning operation produces yarn from fiber. 47 machines of 20 HP each are
running at about 1450 rpm for this purpose.
Winding -> By winding the yarns, spools and cops are made. 14 machines of 5 HP each are used
for winding.
Weaving -> Weaving is a process of interlacement of two series called “wrap” and “weft” yarns
to produce the fabric of desired quality. 208 machines of 1 HP and 22 machines of 3 HP each are
used for weaving.
Damping and Calendaring -> This procedure provides the fabric desired moisture. 2 machines
of 15 HP running for this purpose.
Cutting -> Cutting the fabrics to desired size for making bags. 1 machine of 5 HP appointed for
this.
Sewing -> This work can be done by hand as well as using a sewing machine. 4 sewing machines
is present of 1 HP for sewing.
Pressing -> After preparing the bags they are pressed and bound together for storage and
shipments.
The Pressing Machine:
The pressing machine is the highest power
machine in there. This machine pumps water
in and out under a platform that creates
hydraulic pressure. A three phase 65 HP
induction motor is used for pumping the
water. When the water is pumped in, the
platform rises up. To pump enough water
inside the induction motor needs to run at
certain speed. When the pressure needs to
be decreased, speed is reduced. The platform
then slowly gets down.
So, the pressure depends on the speed of the
induction motor. From torque – speed curve we
see that high resistance at starting rotor
resistance produces high starting torque but less
efficiency at rated speed. Again, low starting
resistance produces low starting torque but high
efficiency. That means its possible to vary the
rotor resistance and, in a result, vary speed.

8. The platform beneath the pressing machine’s motor, there is huge resistance. Workers connects
and disconnects it as needed, decreasing pressure during loading products and increasing it during
packing.
Calculation
Motor
HP
Quantity Total power in KW
65 1 48.49
18 3 40.28
15 54 604.26
5 41 39
3 22 49.23
1 242 158.15
Total Power = 𝟏𝟎𝟓𝟐. 𝟖 𝑲𝑾
Required Transformer size:
Apparent Power: 𝑃𝑖 =
𝑃𝑜
𝜂∗ cos 𝜃
Where,
𝑃𝑖 = 𝐴𝑝𝑝𝑎𝑟𝑒𝑛𝑡 𝑃𝑜𝑤𝑒𝑟
𝑃𝑜 = 𝑂𝑢𝑡𝑝𝑢𝑡 𝑃𝑜𝑤𝑒𝑟
𝜂 = 𝐸𝑓𝑓𝑖𝑐𝑖𝑒𝑛𝑐𝑦
cos 𝜃 = 𝑃𝑜𝑤𝑒𝑟 𝐹𝑎𝑐𝑡𝑜𝑟
So, 𝑷𝒊 =
𝟏𝟎𝟓𝟐.𝟖
𝟎.𝟖∗ 𝟎.𝟖𝟓
= 𝟏𝟓𝟒𝟕. 𝟎𝟔 KVA
Demand load of 440 V, 3-phase, 4-wire panelboard is 69 KVA. Therefore, the transformer size
required for converting the system voltage 11 KV, 3 phase, 3 wire to 440 V, 3-phase, 4 wire is:
Transformer size = 𝟏𝟓𝟒𝟕. 𝟎𝟔 ∗ 𝟏. 𝟐𝟓 = 𝟏, 𝟗𝟑𝟑. 𝟖𝟐𝟓 KVA
Two 1500 KVA transformers will be used for this application.
Required Compensation of Reactive Power:
Reactive Power: 𝑄 = 𝑉𝑙 ∗ 𝐼𝑙 ∗ sin 𝜃
Here, 𝑉𝑙 = 440 𝑉, 𝐼𝑙 =
𝑃𝑜
√3∗𝑉 𝑙∗𝜂∗cos 𝜃

9. So, 𝑄 = 𝑉𝑙 ∗
𝑃 𝑜
√3∗𝑉 𝑙∗𝜂∗cos 𝜃
∗ sin 𝜃
= 440 ∗
1052.8∗1000
√3∗400∗0.8∗0.85
∗ 0.53
= 𝟐𝟐𝟑𝟒. 𝟔𝟗 KVAR = Total Reactive Power
This Q amount of KVAR should be compensated by the capacitor bank.
So, 𝑄 =
𝑉2
𝑋 𝑐
𝑋𝑐 =
𝑉2
𝑄
=
4402
2234.69
= 𝟎. 𝟎𝟖𝟔𝟔
Required Capacitance, 𝐶 =
1
2∗𝜋∗𝑓∗𝑋 𝑐
𝐶 =
1
2∗𝜋∗50∗0.0866
𝑪 = 𝟎. 𝟑𝟕 𝑭
So, 440 V, 0.37 F capacitor needed.
Required Capacitor Bank to Improve Power Factor:
Power factor of the system, cos 𝜃1 = 0.85
Power factor desired, cos 𝜃2 = 0.99
Required KVAR to improve power factor from 0.85 to 0.99 is:
= 𝑃𝑜 ∗ (tan 𝜃1 − tan 𝜃2)
= 1052.8 ∗ (0.62 − 0.14)
= 𝟓𝟎𝟓. 𝟑𝟒𝟒
The Capacitor bank in Platinum Jubilee Jute Mills is of 870 KVAR. Which is just enough for
improving power factor to 0.99.
Estimation of Monthly Bill
Total power consumed =
1052.8∗0.6
0.8
= 789.6 KW
If each motor runs 15 hours a day the total Energy consumed = 15 ∗ 789.6 = 11844 KWh
Per unit of electricity costs 10 taka.
So total cost per month = 𝟏𝟏𝟖𝟒𝟒 ∗ 𝟏𝟎 ∗ 𝟑𝟎 = 𝟑𝟓𝟓𝟑𝟐𝟎𝟎 taka

10. Discussion
For the proper functioning of the industry a total of 363 motors were working with 1052.8 KW
real power and 2234.69 KVAR reactive power. 5 sets of 500 KVAR reactive power was aiding the
industrial loads. 2 sets of 1500 KVA transformers were involved for converting 11 kV HT coming from
electrical substation to 440 V. A capacitor bank of 870 KVAR was responsible for improving the power
factor up to 0.99. Monthly electricity bill of the industry is approximately 35 lakhs taka. Though they
said it’s around 70 lakhs taka. We are assuming it’s because we didn’t take in the costs of the workers’
quarters, fans, ventilation systems and other utilities. The industry owns its workshop which is
responsible for repairing purposed. Faulty machines are immediately taken out of order for repairing.
Conclusion
This visit was very beneficial for us as the process was closely related to our session course. We
studied synchronous and asynchronous motors, generators and their characteristics. From this
industrial visit to Platinum Jubilee Jute Mills Ltd., Khulna we got to observe practical implementation
of our theoretical knowledge. Staffs were very helpful to make us understand every part of the
industry. We are sure that this attachment will help us in future work field.