After several years of long work, research and testing Advanced Lightning Protection Systems Ltd. have created the first fully tested and laboratory proven ESE device made by a UK engineering company. In this post we will give you an overview of the research carried out by some of the leading Universities who were able to assist us in achieving this goal.
In House Design
With trained and experienced engineers in house who have previously manufactured parts for ESE devices we were able to fully design the exterior body and machined parts for our new systems. With various packages, 2D and 3D CAD drawings / models were created for our new device and with a lot of tweaking and editing a final model was created intended for ease of install and reliability.
After CAD modelling was completed, a prototype of the ESE housing was machined to ensure all parts connected together correctly and the device was easy to assembly for installation purposes. Prototype parts are shown below.
Once modelling and design was completed we were then put in contact with several Universities through Wolverhampton City council to help with further development and simulation tests before laboratory testing was carried out.
After the mechanical parts for the ESE system were machined we then needed electronics designed for the device to act as an E.S.E.A.T (Early Streamer Emission Air Terminal). The device was then shown to Aston University who have specialists in electronic development who were able to develop a circuit to enable the system function as an E.S.E.A.T. The device would later be simulated through a computer program elsewhere to see how the electronics enabled the device to function. Below is a short video showing how the ESE works when installed.
At this point in development we were put in contact with a specialist at Manchester University who has expertise in high voltage and electrical power engineering. Now that the electronic circuit was complete from Aston University and an end product was created a simulation was produced to show how the ESE would function. From the simulation it was stated "the field enhancement is 115kV/cm. The magic number used for corona initialisation is 30kV/cm, so it’s almost 4 times that.". Along with a statement from Warwick University "The results look encouraging – seems like your product will function as an ESE device" An image below shows the simulation.
After being in touch with experts at Warwick University we were advised along with laboratory testing to NFC 17-102: 2011 which would need to be completed a simulation test could be performed for wind resistance on our device. Although this testing wasn't necessary to comply to the standard it would serve as an additional test to ensure the system was safe after installation. The simulation test was completed and the results confirmed the system was safe against high speed winds. This is shown below with a FoS of over 2 with winds up to 100 mph.
It was also a specialist in mathematics from Warwick University who advised on Rp (Radius of Protection) enabling us to create a console app which can automatically complete the formula for the Rp, providing us with all the values for the Rp depending on test results from high voltage laboratories.
Full laboratory testing was carried out to NFC 17-102: 2011 which is the French standard as BS EN 62305 doesn't cover ESE devices. A variety of laboratories were used including ICMET Craiova and Cobham Technical Services now known as Element. The ALPS ESE passed testing in accordance to NFC 17-102: 2011 with an advanced triggering time of 35.5 μs. More information on testing & certification can be found here
Radius of Protection
The radius of protection Rp of an ALPS ESE is given by the French standard NFC 17-102 (September 2011).
It depends on the ESEAT efficiency ∆T of the ALPS ESE measured in a high voltage laboratory, on the levels of protection I, II, III or IV calculated according to the lightning risk assessment guides or standards (NF C 17-102 annex A or IEC 62305-2, guides UTE C 17-100-2 or UTE C 17-108) and on the height h of the lightning air terminal over the area to be protected (minimum height = 2 m).
∆T is the triggering time difference between the ESE device and a ‘normal’ reference rod. ∆T should be calculated as the average from 50 repeat tests.
The protection radius is calculated according to Annex C in French standard NFC 17-102. For ALPS ESE, the value of ∆T used in the protection radius calculations is 35.5 µs (∆T = T’SRAT – T’ESEAT = 366.9 – 331.4 = 35.5 µs)
From a console app created this enables us to insert the ∆T from the laboratory tests and gain a full table for the Rp (Radius of Protection). The formula and calculation is shown below.
After the successful launch of our first ESE device we have developed another version which has been modified to achieve a greater advanced triggering time, although currently being tested by laboratories we believe the device will achieve an advanced triggering time of 60 or above with 60 being the maximum no matter the test results.
Special thanks to Warwick University, Aston University and Manchester University for assisting in the development of our ESE systems and other accessories currently in development.