Tests are generally necessary to demonstrate that the equipment under test fulfils the specified requirements and quality standards. The tests may have different purposes, a type test as check and quality assurance for the design of the equipment and a routine test as check and quality assurance for the manufacturing processes. Further tests could be an acceptance test in the factory or on site to demonstrate the quality of the components under test or to check the integrity of the components after transportation and installation. With the introduction of new technologies or the use of higher voltages so-called prequalification test could be required from the customer in order to check the quality of a complete system under on-site conditions but with higher stresses. Such a prequalification test allows the change of the design and adaption of the system as consequences of the test results, but the test takes time in the range of one year or more. An example is the use of extruded cables up to 250 kV for DC transmission systems. Above all a routine test should show that the equipment is able to withstand the test conditions, which are selected according to the stress during the whole time period of service. That means the test stress should be high enough concerning the sensitivity but low enough to prevent an initiation of undetected defects during the test procedure, which may lead to damage after a certain time of service. Therefore, the test requirements are based on experiences concerning the stress and the behaviour of the tested material during normal operation conditions. Furthermore the following parameters have to be taken into account for the type and/or routine tests: regulations by law, requirements, recommendations, mutual agreements on technical specifications, economy. The following chapters are only related to high-voltage testing requirements and recommendations for type and routine tests, without any consideration of regulations by law, mutual agreement on technical specifications and economic factors.

Chapter Contents:

• 16.1 Introduction
• 16.2 Recommendations and definitions
• 16.3 Test voltages
• 16.3.1 DC voltage
• 16.3.2 AC voltage
• 16.3.3 Impulse voltage
• 16.4 Impulse current
• 16.5 Test conditions
• 16.6 Summary
• References

Inspec keywords: test equipment; quality assurance

Other keywords: DC transmission systems; acceptance testing; equipment design; test stress; manufacturing processes; quality assurance; basic testing techniques; economic factors; high-voltage testing requirements; quality standards; prequalification test; routine test

Subjects: Production facilities and engineering