SWITCHING AND SWITCH TRIPPING
Battery systems are used in substations to close and trip high voltage circuit breakers, for transformer protection and safe isolation during normal or fault conditions.
The application requires a high reliability system as energy transmission and distribution is required at all times and cannot move into a situation of unavailability. The application often has a mixed load duty cycle with low level continuous loads and short peak loads for switching operations. Clearly, the battery type must be optimized for the loads and often high performance products are used for solenoid-actuated switch gear and medium to long rate products for spring-actuated switch gear.
Since the battery protects expensive transformers, reliability is foremost in its required attributes. In addition a long life is required as the typical substation life is over 25 years and low maintenance helps to minimise the life cycle cost. Since smaller distribution substations have more extreme temperatures, the ability to function over a wide temperature range is essential.
The advantage of the Ni-Cd battery for this application is that they have a long life and high reliability, with the 20+ year lifetime able to match the system it is supporting. With its steel plate structure it cannot fail in open circuit and is therefore fail-safe and highly reliable. The performance can optimized for the duty cycle and with Ni-Cd there is no tradeoff between long life and performance. With simple and infrequent maintenance and excellent operation under temperature extremes, the attributes provide a low life cycle cost solution.
More information will be found in our Application Note - Switching and Switchgear. (pdf)
Please contact us for further information and support. We can recommend a suitable battery for your specific application.