Energy

 

Access to energy, in conjunction with access to water is one of the biggest drivers of quality of life. Given the current environmental impact issues of traditional
fossil fuel based energy, expanding access to energy in this direction is not an option. This group researches systems and technologies that ensure adequate
secure supply of clean electrical energy into the future. The following thrusts are currently pursued:
 

1. Renewable energy sources

a. Exploring optimal conversion from various sources such as solar and wave energy into electrical energy. The energy available from renewable sources is very dependent on the availability of the source and is often not well matched the the energy usage patterns of consumers. This
places difficult constraints on the system design and needs careful optimization. 
b. Linear synchronous generators for ocean wave-energy harvesting. South Africa has a very long coastline and the potential for harvesting this resource is large. In this thrust it is the actual electrical machine doing the conversion that is being developed.
c. Photo voltaic systems convert solar energy directly into electrical form and offers one of the cleanest and most simple renewable energy source. It is however relatively expensive and as such need to becarefully optimized in order to be able to achieve the largest energy output with the lowest capital investment.
d. Wind energy generators. Both the turbine blade profile as well as the conversion machines are investigated for small costs effective units. These units are intended for standalone islanded operation where conventional grid connections are not available.
 

2. Electrical Energy conversion

a. Electrical energy almost always needs conversion from one from into another. The voltages and currents that are optimal for generation or storage are often not what are required for an end process. Converting from one form to another is possible with Power Electronics and much effort goes into trying to accomplish this conversion with as low a loss as possible. All aspects of this conversion process are investigated from circuit topologies through the devices and components as well as control methods.
 

3. Intelligent energy systems

a. Distributed generation has many advantages over large centralized generation. It also presents many challenges in its design and operation in a stable controllable and safe manner. Mircogrid for sub-urban as well as rural application with renewable sources are investigated with a view to future implementation. The focus lies with the control and metering systems required that are seen as the key drivers. 
 

4. Load identification and understanding of usage context

a. The primary objective of access to energy is to influence the quality of life of people in a positive manner. Before the finer technological aspects of access to energy can be addressed it is very important to  be able to understand the energy needs and requirements of a society. This is affected greatly by factors such as socio-economic aspects and urban or rural settings. In order to discover the energy requirements research in conducted through both direct interaction with the people and indirectly though observation of daily patterns of energy usage. 
 

5. Condition monitoring

a. The major part of South Africa’s conventional generation capacity is aging and starting to reach the end of its design life. This means that the possibility for failures and unplanned outages is increasing. Coupled with this is an increasing demand to reduce the time that plant is turned off for maintenance. These two conflicting requirements can be addressed simultaneous by being able to accurately determine the condition of the plant while it is in operation and to be able to predict impending faults on the machines. If this is known then it is possible to be able to schedule maintenance with the minimum of disruption. Ongoing research investigates these methods by which to monitor the condition of the generating plant. 

PUBLICATIONS

Title Publication Name Authors Year published
PREDICTING THE REMAINING LIFE OF MEDIUM VOLTAGE VACUUM SWITCHGEAR USED IN DISTRIBUTION NETWORKS Proceedings of the 23rd South African Universities Power Engineering Conference (SAUPEC 2015)
J. OReilly
J.M. van Coller
N. Smit
2015
APPARENT SOIL STRUCTURES RELEVANT TO BURIED EARTH ELECTRODES IN SOUTH AFRICA - A RESEARCH PROPOSAL Proceedings of the 23rd South African Universities Power Engineering Conference (SAUPEC 2015) P. H. Pretorius 2015
SENSOR-LESS OUTPUT CURRENT MEASUREMENT FOR SWITCHING CONVERTERS Proceedings of the 23rd South African Universities Power Engineering Conference (SAUPEC 2015)
A.M. Hank
D.J. Cooper
I. Hofsajer
2015
THE FUNDAMENTAL CONSTRAINTS OF CONSTANT VOLTAGE POWER CONVERTERS Proceedings of the 23rd South African Universities Power Engineering Conference (SAUPEC 2015)
J.A. Naud
I.W. Hofsajer
2015
COST EFFECTIVE SOLUTION FOR A SMART HOUSE ENVIRONMENT Proceedings of the 23rd South African Universities Power Engineering Conference (SAUPEC 2015)
D. Horne
Q. Machin
M. Shuma
Iwisi
I. Hofsajer
2015
A SYSTEMS ENGINEERING APPROACH TO ANALYSING MICROGRID CHALLENGES IN SUB-SAHARAN AFRICA Proceedings of the 23rd South African Universities Power Engineering Conference (SAUPEC 2015)
W. Doorsamy
L. Lakay
Doorsamy
W.A. Cronje
2015
A DYNAMIC THREE-PHASE LOAD EMULATOR FOR DISTRIBUTED GENERATION STUDIES IN A MICROGRID LOAD TEST-BED Proceedings of the 23rd South African Universities Power Engineering Conference (SAUPEC 2015)
T.K. Nkalai
M.V. Mabuyakhulu
W.A. Cronje
2015
DYNAMIC POWER REQUIREMENTS FOR CONTROLLED ENERGY STORE USED FOR STABILIZATION OF THREE-PHASE LOW-VOLTAGE STANDALONE MICROGRID Proceedings of the 23rd South African Universities Power Engineering Conference (SAUPEC 2015)
N. Horonga
W. Cronje
2015
A DATA VISUALISATION SOLUTION FOR SMART ENERGY MONITORING SYSTEMS Proceedings of the 23rd South African Universities Power Engineering Conference (SAUPEC 2015)
M.C. Geddes
B.E. Phillips
K.J. Nixon
2015
PERFORMANCE PREDICTION OF WIND TURBINE BLADES: PRELIMINARY TESTING AND RESULTS Proceedings of the 23rd South African Universities Power Engineering Conference (SAUPEC 2015) J. Braid 2015