Breakthrough electronics research by Mining3, has been acknowledged for its potential to improve safety and reliability in underground coal mining. TONY HESELEV reports
Article from resourceful: Issue 10
Researchers are developing a prototype spark testing device that may set a new standard of risk management in the potentially explosive environments of underground coal mines.
The new electronic spark tester is designed to replace the electromechanical spark testing device, which has challenged the industry for 50 years.
The test is performed to ensure power supplies are inherently safe, which means they can't cause an explosion if there's a short circuit on the output terminals of the power supply.
The existing device is used in intrinsic testing and certification of power supplies. It provides only a pass or fail result, with a high degree of variability. Tests are expensive and time consuming, and can be undertaken only at a few specialised laboratories.
Power supplies can pass one day and fail the next, even though the test setups are identical. The device also provides no data or analysis of the response of the power supply during the test, so there is no way of telling why it passed or failed. This can be frustrating for manufacturers trying to get their power supplies certified.
Fortunately, a new electronic spark tester is being developed by Mining3 to provide a more reliable, informative and versatile test method, and deliver better protection against explosions.
Mining3's electronic systems engineer and project leader, Enver Bajram, says the new method simulates sparks – rather than creating real sparks or explosions – and then uses computer analysis.
"It makes a series of measurements using a specially designed electronic loading device and interprets these measurements based on knowledge of spark physics developed from experiments undertaken specifically for this project," Mr Bajram says.
"It measures the transient and steady state performance of a device and then provides an indication of spark energy that could be developed and compares this to an explosive limit."
"This information provides much greater value in terms of design validation and margins of safety."
The new technology will enable intrinsic safety testing to be conducted in factories and onsite to ensure continuing performance and safety of devices.
For end users, in-situ testing of power supplies could ensure continued compliance and a more informed approach to managing risks associated with electrical power supplies in potentially explosive environments.
The electronic testing method also helps manufacturers receive far more informative and reliable test feedback and the possibility of 'factory acceptance' intrinsic safety testing.
For testing agencies and laboratories, the new method is safer for staff and provides greater certainty in results.
The research has been funded by the Australian Coal Association Research Program (ACARP) and undertaken in collaboration with Germany's
National Metrology Institute (PTB). The researchers are planning to carry out a large batch sample test on multiple power supplies of various stages, which has been proposed to ACARP for 2016 funding.
A prototype of the electronic spark tester is scheduled to be available for industry use by the first quarter of 2017.
Mr Bajram says the new technology could also eventually be used in the oil and gas industry.
In December last year, Mr Bajram and his research partner Rajiv Shekhar received an ACARP research and industry excellence award for their work on the new tester.
ACARP Executive Director Mark Bennetts says their progress towards creating the new tester as an alternative technique to the flawed existing methodology was a remarkable achievement.
"The fact that their research has been delivered in collaboration with PTB indicates the potential for international change of both testing and eventually International Electrotechnical Commission standards," he says.
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