Prof. Ramesh Bansal

Professor & Group Head (Power)

Department of Electrical, Electronic & Computer Engineering

University of Pretoria, South Africa email: rcbansal@ieee.org

Addressing some of the challenges of

conventional and renewable power systems

Publications: 230+ (Books: 8, Book Chap.: 14, Journals 129, Conf.: 78

Thesis Supervision: PhD: completed 11 & in progress 14, Masters 13,

Honors over 85

Diversified research in the areas of renewable

and conventional power systems, which includes:

Improvement of efficiency of coal based power plants,

emission reduction and economic dispatch,

Distributed generation

Grid integration of renewable energy (RE): Wind & PV

Hybrid power systems

Transmission pricing & congestion management

Power electronic applications in power & RE

Smart Grid

Electrical Machine (SEIG, DFIG, PMSG, SG), VSD, IM

Power systems analysis: reactive power/voltage control,

FACTS, power quality, stability, faults and protection,

modeling, AI applications in power systems 2

http://www.worldscientific.com/worldscibooks/10.1142/7489

Coal based power plants still play a significant role which provide about

42% of world‟s electricity demands.

China, Australia, and South Africa have more than 70%; and India and US

have over 50% power generation from coal.

Major issues with the power generation from coal based power plants are

large GHG/CO2 emissions and low efficiency.

3

4

Thermal efficiency of coal-fired power plant (source: updated comparison of power efficiency on grid level, 2006, ECOFYS Co.,

2006）

5

𝜼=

• Maximize Q1

• Minimize Q2

• Minimize Q3

• Minimize Q4

Slagging

thickness (inch) Loss of heat

conductivity (%) 1/32 9.5 1/16 26.2 1/8 45.3

3/16 69

6

The geometry of heat transfer process with slagging layer of the case

The temperature distribution of with normal level of slagging

The temperature distribution of with high level of slagging

The temperature distribution of with low level of slagging

X. Liu and R.C. Bansal, “Integrating Multi-Objective Optimization with Computational Fluid Dynamics to Optimize Boiler

Combustion Process of a Coal Fired Power Plant”, Applied Energy, vol. 114, pp. 658-669, 2014.

Research Outcome

7

…Improving Fossil Fuel Boiler Combustion Efficiency

8

• Integrating real time simulation with online learning technology to

improve the power plant boiler combustion process

• To build up a cloud computing, high performance computing, web

services, distributed database and multi-agent supported platform on

which boilers can learn from one another and get real time tuning

services.

X. Liu and R.C. Bansal, “Improving Fossil Fuel Boiler Combustion Efficiency Based on Integrating Real

Time Simulation with Online Learning Technology”, International Journal of Ambient Energy (Taylor &

Francis), Vol. 33, No. 3, pp. 130-141, 2012.

X. Liu and R.C. Bansal, Thermal Power Plants: Modelling, Control and Efficiency Improvement”, book

scheduled for publication with CRC Press, Taylor and Francis in 2015.

Historically, electric utilities have been vertically

integrated, meaning that electric utilities were

responsible for providing its customers with the full range

of electric services including all aspects of generation,

transmission and distribution of electricity.

Electricity supply industry has undergone a rapid change

over the past two decades.

Under the deregulation scheme, the electricity business

has been unbundled into generation, transmission and

distribution sectors and privatization has been

introduced.

9

to satisfactorily allocate the transmission service charges

among all involved participants

to improve the existing transmission pricing in

competitive electricity market by integrating the

transmission loss component with the transmission use

of system (TUoS) charges

with the presence of the renewable generation

integration to the existing grid, the TUoS charging

methodology also need an improvement in order to be

fair and equitable to the market participants

10

Presents a technique which incorporates the

justified distribution factor (JDF) approach has

been proposed to evaluate the transmission line

flows accurately.

Develops a transmission pricing method which

integrates transmission loss component with the

Distribution Factors Enhanced Transmission

Pricing (DFETP) method for pool electricity market

11

N. H. M. Radzi, R. C. Bansal, Z. Y. Dong, M. Y. Hassan, and K. P. Wong, “Integrating Transmission Loss

Component with the Distribution Factors Enhanced Transmission Pricing Method”, Electric Power Components

and Systems, Vol. 23, No. 1, pp. 10-21, 2015.

N. H. M. Radzi, R. C. Bansal, Z. Y. Dong, M. Y. Hassan, and K. P. Wong, “An Efficient Distribution Factors

Enhanced Transmission Pricing Method for Australian NEM Transmission Charging Scheme”, Renewable

Energy (An Elsevier Journal), Vol. 53, pp. 319-328, 2013.

12

Modified 59-bus system of the south east Australian grid

13

SENE: hub approach

SENE: simple approach

„Spaghetti network‟ connection

Transmission configurations

Transmission Pricing: RE Integration

14

Multi-connection terminal station cost of wind

generation and the incremental cost for different types

of connections

explored three types of transmission

configurations, introduced by the

AEMO in order to connect the RE

generation to the existing grid

The existing Australian NEM

transmission pricing methodologies;

CRNP and MCRNP are identified.

The „spaghetti network‟ is not an

efficient and economic option for grid

connection, especially for remote

locations as full cost is borne entirely

by the generators.

The SENE-simple approach is

introduced to overcome the

„spaghetti network‟ drawbacks and to

achieve „economies of scale‟ through

efficient use of the network but

unfortunately, it contributes high

TUoS charges and generation

capital cost.

Therefore SENE-hub approach is the

best connection as total charges for

the generation capital cost and TUoS

charges are well balanced compare

to the other connections.

N. H. M. Radzi, R. C. Bansal, Z. Y. Dong, M. Y. Hassan, and K. P.

Wong, “An Overview of the Australian NEM Transmission Use of

System Charges for Integrating Renewable Generation to Existing

Grid”, IET-Generation, Transmission & Distribution, Vol. 6, No. 9, pp.

863-873, 2012.

N. H. M. Radzi, R. C. Bansal, and Z. Y. Dong, “New Australian NEM transmission use of system charging methodologies for integrating renewable generation to existing grid”, Renewable Energy, Vol. 76, April 2015, pp. 72–81.

…Transmission Pricing: RE Integration

No longer economy to scale with large

generators due to large T&D losses and

grid stability in the event of failure

Small-scale power generation near the

load

Can have large grid integration or micro-

grid (isolated hybrid power system)

Benefits

-Reduction of grid losses*

-Green technologies

15

*D. Q. Hung, N. Mithulananthan, and R.C. Bansal, “A Combined Approach of DG, Capacitor

Placement and Reconfiguration for Loss Reduction in Distribution Networks”, Applied Energy

(An Elsevier Journal), Vol. 105, May 2013, pp. 75-85.

N.C. Hien, N. Mithulananthan, and R.C. Bansal, “Location and Sizing of Distribution Generation

Units for Loadability Enhancement in Primary Feeder”, IEEE Systems Journal, Vol. 7, no. 4, pp.

797-806, 2013.

.

Traditional networks not designed for DGs interconnection

With DG interconnection power flow is bidirectional

Problems can be caused within network such as: ◦ Islanding

◦ Change in fault currents

New protection schemes required

http://www.gwec.net/global-figures/graphs/

Total installed capacity at the end of 2014 was 370 GW.

Wind installed capacity leaders are China 115 GW, USA 66GW, Germany 39

GW, Spain 23 GW and India 22.5 GW, UK 12.5 GW.

Asia 142 GW, Europe 134 GW, North America 78 GW

offshore wind Installed cap. 8.7 GW (2014), UK 4.5 GW,

Europe targets offshore wind 40 GW by 2020 and 150 GW by 2030

UK is the world‟s leading generator of offshore wind farm (300 MW).

Single wind turbine size around 8 MW (220 m height & 80 m blades dia)

17

Increasing Size of Wind Turbine

Wind Farm MW Supplier Status

Dassiesklip 27 Sinovel In Operation

MetroWind 27 Sinovel In Operation

Grassridge 60

Vestas Commissioni

ng

Hopefield 66 Vestas In Operation

Noblesfontei

n 74

Vestas In Operation

Kouga 80

Nordex Commissioni

ng

Dorper 100 Nordex In Operation

Sere 100 Siemens In Operation

Cookhouse 138

Suzlon Commissioni

ng

Jeffreys Bay 138 Siemens In Operation

Large scale wind farms in South Africa

Increase in Wind System rating/Generator and Associated Power

Electronics

World’s installed capacity around 177 GW at the end of 2014 (38.7 GW added in 2014).

21

Distribution system integration in localised

distribution systems

Power Qualities issues

Power Electronics, Storage systems for PV

systems

Large PV Plants Stability issues and issues with

significant PV integration

22

R. Shah, N. Mithulananthan, R.C. Bansal, and V. K. Ramachandaramurthy, “A review of key power system

stability challenges for large-scale PV integration”, Renewable and Sustainable Energy Reviews, Vol. 41, 2015,

pp. 1423-1436.

R. Shah, N. Mithulananthan, and R.C. Bansal, “Damping Performance Analysis of BESS, Ultracapacitor and

Shunt Capacitor with Large-scale PV Plants”, Applied Energy, Vol. 96, Aug. 2012, pp. 235-244.

R. Shah, N. Mithulananthan, and R.C. Bansal, “Oscillatory Stability Analysis with High Penetrations of Large-

scale Photovoltaic Generation”, Energy Conversion & Management, Vol. 66, pp. 420-429, Jan. 2013.

http://jacdigital.com.au/2011/11/sustainability-shapes-queenslands-renewable-future

1.22 MW PV system at UQ: online data

http://www.uq.edu.au/solarenergy/

23

Many under developed and developing countries unable to

provide power to community in remote areas

Power generation through Diesel Generator is high costly with

transportation, O&M cost

Hybrid Power system (Wind-Diesel-PV, etc.) can be a better

option to provide affordable power to isolated communities

24

25

SOPAC Miscellaneous Report 406, August 2005

diesel (2 × 100 kVA), wind (8 × 6.7 kW), and solar (40 kW)

Hybrid Power System at Nabouwalu, Fiji Islands,

Monasavu Hydro Dam (4×20 = 80 MW

Diesel Plant 50 MW (4 ×12)

Butoni 10 MW wind farm (37× 275 kW))

26

27

SG can be regarded as an electric system that

uses information, two-way cyber-secure

communication technologies, and computational

intelligence in an integrated manner for electricity

generation, transmission, substations, distribution

and consumption to achieve a system that is

clean, safe, secure, reliable, resilient, efficient, and

sustainable.

SG survey paper: IEEE com. & Survey tut, 14(2), 2012

Not a replacement of existing grid but complement

to it with features like: Central and distributed generation

Integration of renewable energy

Electric Vehicles

Energy Storage

PMUs

Smart metering

Use of IT to optimize capital assets and reduce O & M

costs

28

SG survey paper: IEEE com. & Survey tut, 14(2), 2012

29

Conv. Grid Smart Grid

Centralized Generation: fossil fuel, hydro, nuclear

Centralized & Dist. Gen., RE, EV, etc.

Power flow unidirectional Power flow bidirectional

One way communication Two way communication

Electromechanical metering Digital metering

Manual monitoring, manual restoration

Self monitoring, self healing

Limited customer choices Many customer choices

S.M. Lukic, J. Cao, R.C. Bansal, F. Rodriguez, and A. Emadi, “Energy Storage

Systems for Automotive Applications”, IEEE Trans. Industrial Electronics, Vol. 55,

No. 6, 2008, pp. 2258-2267.

Significant amount of power generation is likely to continue

from Coal. So there is need to minimize CO2 emission and

improvement in the efficiency of coal fired plants.

To build up a cloud computing, high performance computing,

web services, distributed database and multi-agent supported

platform on which boilers can learn from one another and get

real time tuning services.

Transmission Pricing in Deregulated environment

Power generation though distributed renewable generation

(Wind, PV) are helpful in maintaining clean environment and

reduction of system losses.

Hybrid Power System with proper operation, maintenance &

control strategy can be a better option to provide affordable

power to isolated community.

Smart Grid is the future of Power Systems.

30

31

Thank you for your kind attention!