IEEE 1031-1991 pdf free.IEEE Guide for a Detailed Functional Specification and Application of StaticVAR Compensators.
IEEE 1031 of the thyristor valves is to control the ac current in a reactor bank or to switch on or off a capacitor bank(if supplied).
1)Reactor thyristor valves—The reactor thyristor valves should control the phase current to provide variable
amounts of ac current to the reactor bank, thereby controlling variable inductive vars.
2) Capacitor thyristor valves—The capacitor thyristor valves should switch the ac current by allowing full
current conduction or zero current conduction, thereby providing controlled step changes in capacitive vars.
General Description:
1)The thyristor valves should be designed to ensure satisfactory operation according to the overall performancerequirements and including all necessary accessories.
2) The design of the thyristor support structure should permit easy access by the user for visual inspection,routine maintenance, and handling of the thyristor.
3) Each single-phase thyristor valve should consist of reverse parallel pairs of series-connected thyristors,
including all of the necessary heat sinks, snubber circuits, firing circuits, and control-system signal channelequipment.
4) External connections—Each single-phase thyristor valve should be connected in series with a minimum of
two reactive elements. This will limit the current in the thyristor valves in the event of a reactor or capacitorbank flashover. A three-phase assembly should be made by connecting three single-phase valves and reactorsor capacitor banks in a delta configuration.
Required Design Parameters:
The thyristor valve should be designed with individual thyristors applied in a conservative manner with regard to theirbasic design parameters.
1) The thyristor valve should be designed for maximum overvoltage and overcurrent stresses due to systemfaults and switching.These maximum stress values are as specified in Section 3.
2)The thyristor valve design should include an appropriate allowance for unequal voltage distribution across
individual thyristors in the thyristor valve.A minimum of 10% redundant series thyristors (but no less thanone redundant series thyristor) are required in each singlephase thyristor valve.
3)Thyristor Triggering Means—For fiber-optic systems,two independent triggering systems should be provided.
4)Thyristor Failure Indication—A monitoring means to determine the number of thyristors that have failed should be provided.IEEE 1031 pdf download.