Voltage Management through MV supply_WPS_best practice series
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Modifying electrical supply infrastructure - Voltage managements best kept secret? Wilson Power Solutions Best Practice Series wilson e2 transformer UTILITY CIRCUIT BREAKER HV METERING Dr Lore Grohmann of Wilson Power Solutions explains why modifying electrical supply infrastructure can be the simplest, most cost effective and least invasive voltage management solution for sites with MV supply 50% reduced TRANSFORMER LOSSES typical site voltage 230v lowest possible site voltage 210v Due to prevailing grid conditions, the average supply voltage in the UK is 242V. This relatively high voltage level has remained unchanged despite recent Electricity Quality and Supply Regulations (EQS) aimed at achieving supply voltage harmonisation across Europe. As a result, electricity supply to site through the UK distribution system often runs at a higher voltage than is necessary and is responsible for significant energy losses. Voltage management is an energy saving technique addressing this issue by systematically modifying supply voltage to a site in order to reduce losses in voltage dependent equipment. The need for voltage management has developed an entire new industry with a whole array of companies offering solutions ranging from simple fixed ratio autotransformers to advanced variable ratio equipment. Suppliers of dedicated Voltage management equipment are claiming superiority of their respective offerings and promoting their products as the best available solution. The fact many of these providers would rather you did not know is that for sites with MV supply, a simple, straight forward and cost effective solution exists that doesn’t require any dedicated VM equipment: Modifying incoming supply infrastructure. Replace existing MV/LV transformer(s) with super low loss amorphous transformers – The 2in1 option Most sites with MV supply are currently operating a supply solution. Why? Replacing the supply transformer does not require any additional equipment to be installed. This eliminates the risk of system disturbance, avoids additional transmission losses, minimises the total plant footprint and is virtually maintenance free. Recent field trials have shown that optimising site voltage through supply transformer that is designed to provide a nominal phase voltage transformers can achieve the same (if not better) levels of savings as of 240V. Where sites can benefit from reducing supply voltage, comparable, fixed ratio voltage management units. What’s more, in replacing existing transformer(s) with modern units (such as a super addition to savings made through optimised site voltage, site owners low loss amorphous transformer) that offer a nominal voltage of benefit from energy savings through reduced transformer losses of 230V alongside an extended tapping range which would operate up to £4000 per year (based on a typical 1000kVA unit) making this satisfactorily down to 207V can be an extremely cost effective an attractive 2in1 solution (see below and figure 1). www.wilsonpowersolutions.co.uk Tel: +44 (0)113 271 7588 Email: info@wilsonpowersolutions.c

Tap down your existing transformer The basic option Most distribution transformers have off-circuit selectors installed to allow for manual ratio adjustment to LV side voltage. These “tap changers” typically offer a range of ±5% either in one per cent or 2.5% steps. Tapping down an existing transformer where site supply voltage is higher than required is a low cost option which can lead to a quick, if limited, reduction in energy use. Despite the comparatively moderate savings it is always worthwhile to ensure that transformers are running on the best possible tap setting for a site’s...

The use of high quality copper conductors has been widespread in Europe and the US to reduce load losses with products being promoted as ‘low loss’ transformers. Amorphous metal core technology has been intensively deployed in countries with notoriously overstretched supply networks (i.e. India) for over two decades and has a proven track record of performance. Super low loss transformers combine the two loss reducing approaches, hence the name ‘super low loss amorphous transformers’. Wilson e2 - super low loss amorphous metal core transformers The Wilson e2 transformers are manufactured...