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VOLTAGE STABILISATION TECHNIQUES
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There are many different types of products and techniques involved in voltage stabilisation
and it is important to understand the differences between them when considering a specific application. The situation can become confusing for the lay person when competing manufacturers of voltage stabilisers quite naturally promote their own product by talking
about their advantages whilst at the same time playing down or forgetting to mention the disadvantages. As we manufacture and supply most types of voltage stabiliser we are often asked what the real differences are between them and which is the best for a particular application.
Servo-mechanical Voltage Stabilisers
For many applications we would normally recommend a servo-mechanical voltage stabiliser. At the same time we would want to know the full details of the load and whether or not there are any other specific considerations.
Servo-mechanical voltage stabilisers are a very reliable and economical method of stabilising mains voltage variations of up to 50% and are used for many applications in industry, commerce, mining, aerospace, computing and telecommunications. They use a proven technology that combines solid electrical engineering with electronic sensing and control to give a continuous, smooth and very stable output voltage of ±0.25%. Servo-mechanical voltage
stabilisers have some moving parts, which depending on the application will require a small amount of low-level maintenance after a long period of time. Even with moving parts they are a far more reliable method of stabilising voltages than electronic tap-changing techniques, which due to surges and transients on the mains supply are prone to failure. The long-life and low cost of ownership makes servo-mechanical stabilisers a very economical and reliable solution.
Because of the popularity of this method of voltage stabilisation and the high demand for
models between 2kVA and 60kVA it is possible to purchase some of the more popular
models from stock or with very short delivery times. We can manufacture special servo-mechanical voltage stabilisers up to 2MVA. An example of larger servo-mechanical voltage stabilisers we have recently produced would be a MSX I000kVA stabiliser for a
tanning process plant in Africa The design uses standard components configured in such a
way as to reduce the overall size and weight of the unit without compromising its efficiency. Output voltage is 415/240V with an output stability of ±1%.
For recommendations and information on specific applications please Contact Us.
Alternative techniques
Having stated that servo-mechanical voltage stabilisers are the best solution for most
applications there are always exceptions as some forms of stabilisation are more appropriate to one kind of application than to another. So as a general guide we will review here some alternative techniques we can offer and identify some typical applications we have applied them to.
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Electronic Voltage Stabilisers
Servo-mechanical stabilisers such as our Series TS normally provide the best combination
of economy and continuous stabilisation.
However some applications requiring extremely
fast correction speed or when located in hostile climatic conditions can
be best met by a
solid-state continuous acting electronic voltage stabiliser.
An example of solid-state electronic voltage stabilisers we have produced against quantity requirements is this rack-mounted unit designed for a military application in the Middle
East. This stabiliser has a fast correction speed of 30 milliseconds and provides an output
of 220V at up to 13.6A (3kVA) stable to ±0.5% over an input correction range of ±15%.
Another example of this type of stabiliser is a floor standing model produced to meet a
quantity requirement from an Egyptian telecommunication authority. This is a three-phase stabiliser providing independent correction and balancing of the phases. With an output of 380/220V stable to ±0.5%, the input correction range is -20% to +15%.
For recommendations and information on specific applications please Contact Us.
Tap-Changing Voltage Stabilisers and Conditioners
The majority of applications for voltage stabilisation require the voltage to be corrected to
within close limits. For these applications we would recommend as previously stated servo-mechanical or high speed continuously correcting electronic voltage stabilisers. However
for less critical application where true stabilisation is not required as long as the output
voltage can be maintained within broad limits acceptable to the equipment being supplied,
a tap-changing solution may be acceptable.
Applications such as freezers and air-conditioning units can accept the inevitable voltage
jump that occurs at the moment of tap changing in tap changing stabilisers. Voltage
jumps are common to all tap-changing types of stabiliser and sadly are often not mentioned
by other manufacturers. If used to supply inappropriate loads such as sensitive monitoring equipment tap-changing stabilisers are likely to cause graphic distortion or data loss.
If ignored this will eventually shorten the life of the equipment or cause expensive damage.
There are a number of different tap-changing stabilisers on the market and some are more
reliable than others. A common type used by many manufacturers incorporate electronic
tap-changing techniques, which are prone to failure due to switching stresses; we prefer to
use a technique that employs highly reliable relays with a patented zero-crossing control
circuit. Claude Lyons manufacture to quantity order both basic units and line-voltage
conditioning units incorporating low capacitance ultra-isolation transformers and filtering.
An example of tap-changing voltage stabilisers we have produced against quantity
requirements included specially designed Mains Voltage Compensators (MVC) for worldwide use through the World Health Organisation. Approved to WHO/UNICEF Standard E7/VR.1 & E7/VR.2, these 0.5kVA units are compact, reliable and low cost voltage regulators providing an output voltages of -8% to +9% from input voltage variations of -34% to +26%.
For recommendations and information on specific applications please Contact Us.
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