Investigation and Minimization of Power System Losses in Bangladesh

Presentation on Investigation and Minimization of Power System Losses in Bangladesh

INTRODUCTION

Providing access to affordable and reliable electricity to all citizens by 2021 is a befitting national goal of the Government of Bangladesh (the Government). GOB is currently working with an interim target of providing electricity to 60% of the population by 2010. At present electricity coverage in Bangladesh is only 43% and per capita electricity consumption is about 140 kWh which is one of the lowest in the World.

As power projects are capital intensive, developing adequate generation, transmission and distribution facilities to provide reliable and quality power supply to the population is a challenge for the Government. Therefore, to materialize GOB’s vision, active participation of the private entrepreneurs and power sector reform & restructuring are essential.

The performance of Bangladesh power sector in last two decades fell short of expectation of our citizen. High system losses in the sector, large amount of accounts receivable and inadequate tariff have been affecting the financial viability of the utilities and attractiveness for investment. Acute scarcity of resources hinders financing the huge cost required for the development of the sector. Absence of clear organizational goals, adequate financial and commercial autonomy and lack of adequate incentives resulted inefficiency in the utility management.

OBJECTIVE

1. To investigate the power system status in Bangladesh.
2. To investigate the nature of technical and non technical losses in power system.
3. To investigate the source of technical and non technical losses in power system.
4. Calculation of losses in power system.
5. To establish a technique to reduce the losses.

METHODOLOGY

The transmission and distribution losses data of BPDB,PGCB,DPDC (DESA), DESCO and REB are collected. Their system performance are determined in terms of percentage. Then various minimization techniques are studied to reduce the transmission, distribution and non-technical losses in electrical power system in Bangladesh.

Transmission & Distribution Power System of Bangladesh

Owner & Regulator:

Power division, ministry of energy and mineral resources.

Generation:

Bangladesh power development board (BPDB).

Independent power producers (IPPs).

Transmission :

Power grid company of bangladesh Ltd. (PGCB).

Distribution :

Bangladesh power development board.

Dhaka electricity supply authority (DESA).

Dhaka electric supply company Ltd. (DESCO).

Rural electrification board through rural electric co-operatives.

Fig: 1. Power transmission & distribution system in Bangladesh.

Key problem faces in Power Sector of Bangladesh

Key Problem are :

1. Load shedding and voltage variation.
2. Operating Inefficiency.
3. System loss.
4. Unadjusted tariff structures and ineffective billing procedures.
5. Limitation and Ineffectiveness of the Electricity Acts and Magistracy.

Types of System Loss

System Losses are Generally two Types-

1. Technical losses.
2. Non-technical losses.

Technical Losses are Classified as Follows-

Transmission losses.

Distribution losses.

Causes of Technical Losses

Main Cause of Transminission Losses:

1. Skin effect.
2. Corona loss.
3. Low power factor.
4. Induction and radiation losses.
5. Operating the system at high voltage.
6. Power Transformer losses.

Cause of Distribution Losses:

1. Lengthy lines more than standards.
2. Overloading of lines.
3. Abnormal operating condition at which the distribution transformers are operated.
4. Operation of primary and secondary distribution system at low power factors.
5. Lose connections at joining in the systems link at the tapping of lines, jumpering of the switch contacts, termination at the transformer bushing.
6. Unequal load distribution among three phase in LT systems causing high neutral currents.
7. Low voltages at the consumers terminals causing higher drawl of currents by inductive loads.
8. Installation of distribution transformers away from the load center.

Cause of Non-technical Losses

External Causes:

1. Electricity theft i.e.
2. Frauds.
3. Illegal connections.
4. Meter tampering.

Internal Causes:

1. Administrative.
2. Defects on installation.
3. Data base errors.

Fig: 2(a)

Fig: 2(b)

Figure: 2. Methods of electricity theft.

Minimization Technique of Technical Losses

Minimization of Technical Loss:

1. Expanding the transmission capacity:
   i. Building new lines-AC or DC.

   a. High voltage AC (HVAC).

   b. High voltage DC (HVDC).

   ii. Upgrading existing lines. Figure: 3. An HVDC station.

   a. Raise the voltage.

   b. Increase the size and/or number of conductors per phase.

   c. Use high-temperature conductor materials.

   iii. Utiliizing existing lines closer to the thermal limits.
   
   Figure: 3. An HVDC station.
2. Flexible ac transmission system (FACTS):
   FACTS equipment increases the capacity and stability of AC lines This device can absorb and deliver reactive power to the system based on the variations of the system voltage fluctuations. The most sophisticated of these devices is the Unified Power Flow Controller (UPFC). The UPFC can regulate both real and reactive power in a line, allowing for rapid voltage support and power flow control. It is estimated that FACTS devices can boost the transmission capacity of lines now limited by voltage or stability considerations by as much as 20 to 40 percent.
3. Power factor correction:
   There are various power factor correction methods:

   1. Static var compensator(SVC).

   2. Fixed capacitors.

   3. Switch capacitors.

   4. Synchronous condensers.

   5. Static synchronous compensator(STATCOM).

   6. Modulated power filter capacitor compensator.

Figure: 4(a).Synchronous condenser

Figure: 4(b). Pole capacitor.

Non-technical Loss Minimization Strategies

Present Status of Meter reading in Bangladesh:

1. Highly Person dependant.
2. Human errors cannot be avoided.
3. Accessibility of meters in rural or agricultural zones.
4. Billing done mainly on estimated or monthly average basis.
5. Inability to monitor and control discrete loads.
6. Billing cycle requires excessive time.
7. Energy Audits performed based on bill collection which is highly inaccurate.
8. Meter data used only for billing, cannot help in analysis like demand analysis, energy audit, pinpointing losses, etc.

Fig:5. Existing network of power system in Bangladesh.

Introduction to Automatic Meter Reading System (AMRS):

AMR (Automatic Meter Reading) is a technology gives utilities the ability to obtain meter-reading values remotely without having to physically visit and manually read the customer's electric meter. AMR allows us to collect an actual meter reading without entering consumer’s property to read the meter. The reading on meter is transmitted through various transmission formats and protocols like GPRS, RF, RS 485, PLC (Power Line Carrier).

In AMR System:

1. Staff do not need to leave the office to read meters.
2. The meters’ data is automatically gathered by the computer system.

Fig:6. AMR network architecture.

Connectivity in AMR Architecture:

1. GSM/GPRS Based Communication:

   Single stage communication between Meter and central station through GSM modem.

2. Hybrid Communication:

   Two stages of communication in AMR System.

Figure:7(a). GSM Based communication.

Figure:7(b). Hybrid communication.

Primary Components:

1. Meter Interface Module

   i. Electro - optical interface.

   ii. Signal processing electronics.

   iii. RAM & program memory.

2. Communication System.
   i. GSM network

   a. GSM modem.

   b. Antenna.

   c. Retrofit card.

   ii. Power line

   a. Data concentrator unit (DCU).

3. Central Office Equipment
   i. Modems.
   ii. Central server
   iii. Client software for data acquisition and data analysis.

Figure: 8(a). GSM modem.

Figure: 8(b). Retrofit card.

Figure: 8(c). DCU.

AMR Features/functions:

Figure :9. AMR Feature.

Conclusion

Any improvement in system and lowering system loss can be brought out if organizational structure properly designed, technical and non technical problems are identified and measures taken to overcome the same as far as practicable. It has been observed that both the technical and non technical loss are high in which adversely affect performance of system, stands as a barrier to expand facilities with foreign aid and thus adversely affecting economic development of the country. Thus all round effective and sincere measures warrant immediate attention of the concerned authorities.

Submitted by Md.Rakibul Islam and Md. Kamal Uddin