Accelerated reliability testing

In Europe, and the rest of the world, the smart meter roll out (or preparation of this roll out) takes place on a large scale. These are major projects with high investments where a number of parties are involved.

Perform accelerated reliability testing

Although the various stakeholders made cost / benefit analyses before the start of the roll out, the real life time of the meter is not exactly known. The whole business case is based on a certain life time expectation of the meters. Henri Schouten, Business Development Manager Utilities at NMi explains: “You can make estimations, and certain calculations but those do not provide a 100% guarantee. One of the methods to have more information and more certainty on the life time of the meter is the execution of Accelerated reliability testing. At NMi we developed a service to conduct these kind of tests, based on the IEC standard 62059-31-1. That document describes methods to perform accelerated reliability testing. The output is an estimated life time of the meter, based on real tests.”

Application of the IEC 62059-31-1 method

As described in this standard thirty samples of a meter type are exposed to a certain stress condition. In total there are five stress conditions. Per stress condition it is checked at which moment a defect arises and which defect that is. Afterwards, based on mathematics, it is possible to calculate when those defects will occur and to calculate the expected life time of the meter under normal conditions. The stress conditions consist of elevated temperature and humidity. The lower the elevated levels are the longer the necessary test will take.

Alternative method for pre-testing

In order to avoid long testing time when applying the IEC 62059-31-1 standard an alternative method could be applied for pre-testing. This can be done by applying the most severe test conditions only, while using some fixed values for some parameters during the calculations. By choosing this scenario, the test remains compact and more cost effective and it gives already good information whether a meter is reliable.

NMi is prepared to expose meters to stress conditions and inform you on the expected life time

The big advantage of executing the accelerated reliability testing for energy suppliers or utilities will be to have more and better information on the expected life time of the meters that will be installed. “This new service is very helpful for both meter manufacturers and utilities. At NMi we are prepared to expose at least 30 meters to those stress conditions, with the mathematics implemented in order to make the appertaining calculations. That makes NMi ready for this type of testing.”

For more information about the Accelerated reliability testing, you can contact Henri Schouten.

Henri Schouten

Henri Schouten

Business Development Manager Utilities, Worldwide

Expert for all utility residential meters (electricity/ gas/ water/ heat). Member/ chairman of multiple IEC, CENELEC, OIML and WELMEC groups. Chairman of the Dutch mirrorgroup NEC13. One of the writers of OIML R137.