IEC 61954 pdf download.Static var compensators (SVC) – Testing of thyristor valves
1 Scope
This International Standard defines type, production and optional tests on thyristor valves used in thyristor controlled reactors (TCR), thyristor switched reactors (TSR) and thyristor switched capacitors (TSC) forming part of static VAR compensators (SVC) for power system applications. The requirements of the standard apply both to single valve units (one phase) and to multiple valve units (several phases). Clauses 4 to 7 detail the type tests, i.e. tests which are carried out to verify that the valve design meets the requirements specified. Clause 8 covers the production tests, i.e. tests which are carried out to verify proper manufacturing. Clauses 9 and 10 detail optional tests, i.e. tests additional to the type and production tests.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply: 3.1 thyristor level part of a thyristor valve comprising a thyristor, or thyristors connected in parallel or antiparallel, together with their immediate auxiliaries and reactor, if any 3.2 thyristor (series) string series connected thyristors forming one direction of a thyristor valve 3.3 valve reactor reactor incorporated within some valves for limitation of stresses NOTE For testing purposes it is considered an integral part of the valve. 3.4 valve section electrical assembly, comprising a number of thyristors and other components, which exhibits pro-rated electrical properties of a complete thyristor valve but only a portion of the full voltage blocking capability of the thyristor valve and which can be used for tests 3.5 thyristor valve electrically and mechanically combined assembly of thyristor levels, complete with all connections, auxiliary components and mechanical structures, which can be connected in series with each phase of the reactor or capacitor of a SVC 3.6 valve structure physical structure which insulates the valves to the appropriate level above earth potential and from each other 3.7 valve base electronics VBE electronic unit, at earth potential, which is the interface between the control system of the SVC and the thyristor valves 3.8 multiple valve unit MVU assembly of several valves in the same physical structure which cannot be separated for test purposes (e.g. three-phase valves) 3.9 redundant thyristor levels the maximum number of thyristor levels in the thyristor valve that may be short-circuited, externally or internally, during service without affecting the safe operation of the thyristor valve as demonstrated by type tests; and which if and when exceeded, would require either the shutdown of the thyristor valve to replace the failed thyristors, or the acceptance of increased risk of failures 3.10 voltage breakover (VBO) protection means of protecting the thyristors from excessive voltage by firing them at a predetermined voltage
4 General requirements for type, production and optional tests
4.1 Summary of tests Table 1 lists the tests given in the following clauses and subclauses.4.2 Objectives of tests 4.2.1 General The tests described apply to the valve (or valve sections), the valve structure and those parts of the coolant distribution system and firing and monitoring circuits which are contained within the valve structure or connected between the valve structure and earth. Other equipment, such as valve control and protection and valve base electronics may be essential for demonstrating the correct function of the valve during the tests but are not in themselves the subject of the tests. 4.2.2 Dielectric tests 4.2.2.1 General Tests for the following dielectric stresses are specified: – a.c. voltage; – combined a.c. and d.c. voltage (TSC only); – impulse voltages. In the interest of standardization with other equipment, lightning impulse tests between valve terminals and earth and between phases of an MVU are included. For tests between valve terminals, the only impulse test specified is a switching impulse. 4.2.2.2 Tests on valve structure Tests are defined for the voltage withstand requirements between a valve (with its terminals short-circuited) and earth, and also between valves for MVU. The tests shall demonstrate that – sufficient clearances have been provided to prevent flashovers; – there is no disruptive discharge in the insulation of the valve structure, cooling ducts, light guides and other insulation parts of the pulse transmission and distribution systems; – partial discharge inception and extinction voltages under a.c. and d.c. conditions are above the maximum steady-state operating voltage appearing on the valve structure.
IEC 61954 pdf download
