Keep in touch with meI'm using Intch to connect with new people. Use this link to open chat with me via Intch app
Work Background
EnergyFlexibility.org - Energy System Planning & OptimisationAdvisor
May. 2023London, England, United Kingdom
PowerON Technologies (Pty) LtdDirector
Mar. 2019Pretori
Medium Voltage Technologies (Pty) LtdDirector
Feb. 2019Pretoria
ArioGenix (Pty) Ltd ("Ario")Chief Technical Officer
Sep. 2016 - Oct. 2018Pretoria
SPD Electrical Engineers (Pty) LtdDesign Engineer
Jan. 2012 - Jan. 2017Pretoria
SPDNew multilevel inverter cable tester
Jan. 2012 - Dec. 2016Johannesburg Area, South AfricaRecently I have designed, manufactured and delivered a new type of medium voltage cable tester, and it has been operating successfully for more than 2000 hours. I have previously posted about this project, and it has now been completed successfully and it has several advantages over conventional resonant cable testers. The first advantage of this system is, that unlike the state-of-the-art systems, which work as either variable inductance or variable frequency or a combination of both, this system operates at fixed frequency and requires no resonant (variable) inductor, which makes it much simpler to operate (there is no need to find the resonant frequency of the load, this system operates at 50Hz or 60Hz). The second advantage is that it only draws the active power from the primary supply, which is less than 4% of the load kVA. This means that for an on-site mobile tester the Diesel Generator is much smaller than the state of the art system, where the primary power is a function of the Q of the resonant circuit, which can be quite high. The third advantage of my system is that it can actually perform full three phase test, whereas all the state-of-the-art systems on the market today are single phase systems (limited by the size and cost of the resonant components). It is totally impractical to even consider a three phase system using resonant technology, whereas with my system it is simple (because it does not have large, bulky and expensive resonant chokes). Being able to do a three phase test will reduce the test time of a three phase cable because all three the conductors can be tested simultaneously, and this is more representative of the actual operating conditions (as opposed to testing one conductor at a time with the single phase resonant system).
SPD Electrical Engineers (Pty) LtdMulti-Battery System Renewable Energy Systems
Jan. 2010 - Dec. 2015ChloorkopAt Megatron I developed a unique battery management system for Diesel Generators and renewable energy sites. It allows the optimal operation of batteries in these applications, by ensuring that the battery is never subjected to micro-cycling, that the battery is charged exactly in accordance with the charge profile requirements of the battery manufacturer, circulating currents are eliminated, and finally allowing the battery to cool down after a charge cycle.
This is achieved by taking the single large battery bank, which for example would be made up of two strings of cells in parallel, and separating it into two separate strings of cells. Each of these strings is charged and discharged separately. For example, one string would be charged from the primary power source, while the other is used to supply the load. The result is that the string on charge is never subjected to micro-cycling, because it is no longer connected in parallel with the load while charging. By separating the two strings, circulating currents between the batteries are eliminated as well. The system can be applied to any number of strings. Another benefit of this, is that the warranty period of the cells can be extended, because each string is only cycled every secondary (in the case of a two battery system). For example, in a system where the original bank of batteries is separated into four individual strings, the ratio is four, meaning that every string is only cycled every fourth day, resulting in a fourfold increase in the warranty period.
This concept was verified by First National Batteries, a local battery manufacturer at their East London test laboratories. The cells tested operated for more than 2000 cycles, and while the battery retained 85% of its working capacity over this period. A patent was filed.
SPD Electrical Engineers (Pty) LtdDiesel Generator Optimization System using Durathon SMH Batteries
Jan. 2010 - Dec. 2015ChloorkopA Diesel Generator Optimization System developed for Telco sites, and patented. It comprised two Durathon SMH batteries. It operates by running the Diesel Generator to charge the batteries, and then switch of the Diesel Generator while the load continues to supplied from the now fully charged batteries.
The unique feature of the system is that each battery is supplied from the Diesel Generator via its own bank of rectifiers, and the load is connected to each of the batteries via its own bank of inverters. This arrangement allows the charging and discharging of each battery to be controlled individually and accurately. A key factor in the operation of the Durathon SMH battery is the regulation of its internal temperature, and by being able to regulate the charge and discharge current, the internal temperature can be regulated to within a pre-set band.
The system has been deployed operationally on various sites in South Africa and Nigeria, and has lead to fuel savings at least 50%.
SPD Electrical Engineers (Pty) LtdMultilevel Inverter Development for Grid Tied PV Applications
Jan. 2010 - Dec. 2016ChloorkopA cascaded multilevel inverter was developed, using either a binary or ternary arrangement, a further feature is the implementation of either primary or secondary inverter connections.
With a primary connection, the inverters are connected to the primary side of the transformers, while transformer secondary windings (with either binary of ternary secondary windings), are connected in series to produce the required load voltage. The closed loop control is implemented using the primary side inverters. Secondary side switching can also be utilized, where each of the inverters are fed with DC from its own regulated and isolated power supply. Both of these applications have their own unique field of application, providing a high performance, high power power supply with a very high bandwidth.
This technology has been developed for use in grid tied PV installations, and the result is a low cost, high performance system that competes with imported units. In the PV application, the MPPT function, which is normally implemented as a open loop configuration, has been replaced with closed loop MPPT, utilizing a solar pyranometer. This ensures verifiable, optimal energy harvesting at all times, a key factor in ensuring the highest return from the PV power plant.
The same UEPC technology is also being applied in the design of a very cost effective UPS.
ClearlineDesign Consultant
Jan. 2008 - Dec. 2010Midrand,At Clearline I continued with the development of the IPS (Integrated Power System) for Neotel, designing a SCR based source selector switch.
In addition I was also involved in the development of a binary tap changer for a transformer with the purpose of acting as an accurate AC voltage stabilizer. The unit is able to vary the load voltage in 1V increments, while the input voltage can vary with 50%. The design had several unique features, and a local patent was filed.
I was also involved in the development of a single phase SCR soft starter for air conditioners This soft starter was completed and several hundred units were sold to Neotel, which reduced the peak current demand on their sited significantly.
Liquid Intelligent Technologies South AfricaElectrical Engineer
Jan. 2007 - Dec. 2008WoodmeadDuring the start of the Neotel network, I was employed to develop the power systems for the various facilities, ranging from the base stations to the data and switching centres. I introduced the concept of a standardized power systems, which was called the "IPS" (Integrated Power System). The IPS was used throughout the network.
The IPS proved to be reliable and cost effective solution. It basically comprised all the power conversion (rectifiers & inverters), surge protection, batteries and circuit breakers normally required, all built into a single 19" enclosure.
Self EmployedDesign Engineer
Jan. 2006 - Dec. 2007PretoriaDuring this period I developed a range of electronic soft starters for Squirrel Cage Induction Machines. The design had some unique features, such as a single, ultra-compact control electronics card that were used for the entire range of soft starters, and the card included active trigger modules for the SCR's or thyristors. The design further incorporated a very efficient heatsink design, which lead to a very compact overall product design. The soft starters also included a circuit breaker and motor protection relay function, which meant that it was a fully, self contained unit. The design was suitable for operation in harsh environments.
Self EmployedDesign Engineer
Jan. 2006 - Dec. 2007PretoriaDuring this period I developed a range of electronic soft starters for Squirrel Cage Induction Machines. The design had some unique features, such as a single, ultra-compact control electronics card that were used for the entire range of soft starters, and the card included active trigger modules for the SCR's or thyristors. The design further incorporated a very efficient heatsink design, which lead to a very compact overall product design. The soft starters also included a circuit breaker and motor protection relay function, which meant that it was a fully, self contained unit. The design was suitable for operation in harsh environments.
CBiChief Engineer - Standard Products
Jan. 2005 - Dec. 2006ElandsfonteinDuring my time at CBi I was responsible for the design of the standard range of circuit breakers. My work involved overseeing the design improvements, as well as aspects such as failure analysis. I left CBi to start my own business supplying them with a range of electronic soft starters for Squirrel Cage Induction Machines.
SPD Electrical Engineers (Pty) LtdDesign of Accelerated Ageing Rigs for Medium Voltage Cables
Jan. 2002 - Dec. 2016Stanford road, Port ElizabethThe 500Hz/19kV XLPE cable accelerate ageing rig, as well as a 50Hz/25kV a general purpose ageing rig, had to be replaced. I have been contracted to design and manufacture both of these accelerated ageing rigs.
This opportunity to replace the 500Hz/19kV XLPE ageing rig was used to further develop the UEPC (cascaded multilevel inverter) technology.
The objective is to design and build a system that does not require a resonant secondary circuit at all, but by making use of the unique features of the UEPC, a solution is being developed that is much smaller than conventional designs, while still only drawing the active (losses) component from the primary source, while also supplying the reactive load power to the cable.
The system is being patented.
Denel DynamicsFacility Manager
Jan. 2001 - Dec. 2003IreneDuring my time with Denel, I was the manager for the fire control system of the surface to air defense system. Some of the certification issues involved EMI certification of the fire control electronics.
MH Automation InternationalDesign Engineer
Jan. 1995 - Dec. 2001MidrandI worked as a consulting design engineer for MH Automation on the development of a cyclo converter as well as a DC/DC variable speed drive, both for overhead cranes. The DC/DC variable speed drive was based on a unique patented design, and the development work was aimed at replacing the resistor/contactor controllers used on DC motors that drives overhead cranes. The cyclo converter was developed as an alterantive to modern IGBT variable speed drives, and the reasoning was that the cyclo converter was more efficient and could handle regeneration more efficiently than IGBT variable speed drives. The cyclo converter was also meant to be more robust than the IGBT variable speed drives.
Advanced Technologies and EngineeringProgram Manager
Jul. 1989 - Jun. 1992Midrand, South AfricaDuring my time at ATE, I started a project to develop a variable speed drive for mine locomotives, building on the work I had done at GEC(SA). I was also enrolled for my D. Eng while I was employed at ATE. The work resulted in a working system being developed, but it never entered production. I left ATE to start my own business, developing variable speed drives and various types of inverters.
GECDesign Engineer
Jan. 1985 - May. 1987Driehoek, GermistonDuring my time at GEC(SA) I was employed as an engineer in training. I worked on the development of the control system for a low voltage, battery operated variable speed drive for mine locomotives. In particular I was responsible for the development of the microprocessor based control system. At the time I was also registered for a M. Eng at Rand Afrikaans University, which I completed in 1987. During this time I also worked at the GEC variable speed drives factory in Rugby, England, where I continued with the development of the mine loco variable speed drive control system.
Intch is a Professional Networking App for the Future of WorkSee more people like Andries on Intch
300k+ people
130+ countries
AI matching
Get Intch if you'd like to
501717 people
38
Entrepreneur / 3x Tech Startup / Marketing and Growth @ Morlean Trading Group
22
Environmental Coordinator and Officer
17
CTO / Solutions Architect
57753 people
30
Senior Business Consultant @ Collabitec Pty ltd
21
Project Manager/Consultant @ A Steyn Consulting
22
Founder @ Acorn41