Electricity: measuring and testing – Fault detecting in electric circuits and of electric components – Of individual circuit component or element
Patent
1995-02-02
1996-05-28
Karlsen, Ernest F.
Electricity: measuring and testing
Fault detecting in electric circuits and of electric components
Of individual circuit component or element
340635, G01R 3126
Patent
active
055215262
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
The present invention relates to a method for checking the condition of an optional semiconductor position included in an electric semiconductor valve, for example a valve in a converter for conversion between alternating current and high-voltage direct current, which semiconductor valve comprises a plurality of semiconductor positions with mutually series-connected semiconductor devices, and to a device for carrying out the method.
The device comprises signal-generating members for generating and applying to the firing channel of the semiconductor position alone a test firing signal, a sensing member for timely studying an indicating signal delivered by the indicating channel of the checked semiconductor position, and an evaluation member for determining and indicating the result of the study.
The term "semiconductor position" in this application means a component group comprising a controllable semiconductor device, such as, for example, a thyristor or a gate turn-off thyristor (GTO thyristor), resistors and capacitors, arranged in a conventional manner at the semiconductor device, for voltage protection of the semiconductor device and for voltage division with other semiconductor positions included in the valve, a firing channel for receiving and transmitting firing signals for the semiconductor device, an indicating unit for generating an indicating signal when the voltage across the semiconductor device in its forward direction exceeds a predetermined value, and an indicating channel for delivering the indicating signal.
The term "semiconductor valve", or just "valve", in this application means a set of a plurality of semiconductor positions with mutually series-connected semiconductor devices, which during normal operation electrically function as a unit.
The firing and indicating channels may comprise, in a manner known per se, light guides for non-galvanic signal transmission between different potential levels and may then at their end points comprise members for conversion between electric signals and light signals.
The semiconductor device may be electrically fired or directly light-fired. In the former case, circuits designed in a manner known per se for conversion of a firing signal received in the form of a light signal into an electric signal, adapted to be supplied to the gate of the semiconductor device, may be associated with the indicating unit. In the latter case, the received firing signal may be directly applied to the semiconductor device, via the firing channel, in the form of a light signal. The indicating signal may be of a short type, which means that a short pulse is delivered when the voltage across the semiconductor device passes the predetermined value in an increasing direction, or of a long type, which means that an indicating signal is delivered as long as the voltage exceeds the predetermined value. Long indicating signals may consist of a continuous signal or be in the form of a pulse train.
BACKGROUND ART
An electric valve, for example included in a converter for conversion between alternating current and high-voltage direct current (HVDC converter), comprises a usually large number of mutually series-connected semiconductor devices in the form of thyristors. A control system, located at ground potential, for the converter generates a firing order for the valve and a control system for the valve, also located at ground potential, generates as a result of the received firing order a firing signal for each one of the thyristors included in the valve. These firing signals are received by a firing channel which is associated with each thyristor and which transmits the firing signal to an electronic unit associated with each thyristor. The electronic unit, which is at the potential of the thyristor, comprises, in the case with electrically fired semiconductor devices, circuits for converting a firing signal received as a light signal into an electric firing pulse which is applied to the gate of the thyristor, as well as an indicating unit. Where the thyris
REFERENCES:
patent: 4471301 (1984-09-01), Durov et al.
patent: 4600917 (1986-07-01), Seki et al.
patent: 4651088 (1987-03-01), Sawada
Nyberg Krister
Seppanen Ari
Asea Brown Boveri AB
Karlsen Ernest F.
Kobert Russell M.
LandOfFree
Method and a device for checking the condition of semiconductor does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and a device for checking the condition of semiconductor , we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and a device for checking the condition of semiconductor will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-789515