Detail of GB/T 31487.2-2015

Introduction of GB/T 31487.2-2015

Direct current de-icing devices—Part 2: Thyristor valves 1 Scope This part of GB/T 31487 specifies the basic requirements for the function, design and test of thyristor valves of DC de-icing devices. This part is applicable to water cooling thyristor valves of DC de-icing devices. It may also serve as a reference for thyristor valves adopting other cooling methods. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. GB/T 3859.1-2013 Semiconductor converters - General requirements and line commutated converters - Part 1-1: Specification of basic requirements GB/T 13498 Terminology for high-voltage direct current (HVDC) transmission GB/T 16927.1 High-voltage test techniques - Part 1: General definitions and test requirements GB/T 20990.1-2007 Thyristor valves for high voltage direct current (HVDC) power transmission - Part 1: Electrical testing GB 50150-2006 Standard for hand-over test of electric equipment electric equipment installation engineering IEC/TS 60815-1: 2008 Selection dimensioning of high-voltage insulators intended fuse in polluted conditions - Part 1: Definitions, information general principles IEC 61803: 2011 Determination of power losses in high-voltage direct current (HVDC) converter stations with line-commutated converters 3 Terms and definitions For the purposes of this document, the terms and definitions given in GB/T 13498 and the following apply.   3.1 valve electrical and mechanical combination composed of power electronic devices and auxiliary components, which can realize unidirectional or bidirectional conduction Note: At present, the commonly used valves include diode valves, thyristor valves, insulated-gate bipolar transistors (IGBT), etc. 3.2 thyristor valve valve whose power electronic devices are thyristor valves 3.3 converter electrical device capable of realizing complete commutation function 3.4 single valve valve composed of several thyristor levels in series, which is an arm of 6-pulse converter 3.5 thyristor level component of a valve, which consists of a thyristor or several parallel thyristors and auxiliary equipment adjacent to them 3.6 valve electronics electronic circuit that performs control, monitoring and protection functions at valve potential 3.7 valve base electronics electronic equipment that provides an interface between a ground potential control equipment and valve electronics or valve device, also known as a valve interface electronic equipment 3.8 firing angle time from the forward zero crossing of the ideal sinusoidal commutation voltage to the beginning of the forward current conduction, measured from an electrical angle   3.9 rated direct current direct current (average value) output by the converter according to the specified load conditions and service conditions 3.10 maximum direct current maximum direct current output by the converter to the load under specified operating conditions (theoretically within an infinite time) Note: Generally, there are different values under different cooling media and ambient temperature. 3.11 2h overload direct current direct current that the converter can output to the load within the specified 2h Note: Generally, there are different values under different cooling media and ambient temperature. 3.12 maximum ideal no-load direct voltage maximum direct voltage (Udi0max) of the converter under no-load condition Note: At this time, all kinds of voltage drops and grid voltage fluctuation factors are ignored. 3.13 rated direct voltage average value that the direct voltage output by converter shall reach under the specified conditions 3.14 rated direct power product of rated direct voltage and rated direct current of converter 3.15 coefficient of current distribution ratio of the average value of branch current in parallel operation to the maximum branch current value when the thyristor valve of DC de-icing device adopts double-bridge parallel connection type 3.16 rated junction temperature maximum junction temperature allowed for normal operation of thyristor   3.17 large angle and high current operation operation mode in which DC de-icing device outputs rated direct current output and the firing angle is approximately 90° 3.18 zero power test test for inspecting the direct current control function and current withstand capacity of the DC de-icing device, in which the direct current side of the DC de-icing device is short-circuited through a reactor and the direct current is increased to the set value 4 Technical requirements 4.1 Environmental conditions The normal use environment conditions of thyristor valve of DC de-icing device include the following aspects: a) the altitude is less than 2,000m; b) the ambient temperature is not less than -20°C and not higher than 50°C; c) the maximum relative humidity is 85% (below 20°C); d) the pollution grade is b; e) the magnitude of the earthquake is not more than Grade 8; f) the frequency fluctuation range of AC power grid shall not exceed ±5%. Note 1: When the altitude is greater than 2,000m, the altitude correction design shall be carried out according to relevant standards. Note 2: The outdoor pollution grades are designed generally according to Grade d in IEC/TS 60815-1: 2008. 4.2 Access system The converter of DC de-icing device should be connected to the low voltage side (10kV or 35kV) of the main transformer meeting the de-icing capacity requirements through special converter transformer or commutation reactor, or directly connected to the low voltage side of the main transformer. Otherwise, it shall be connected to the upper power bus through a special transformer. 4.3 Load properties

Contents of GB/T 31487.2-2015

Foreword i 1 Scope 2 Normative references 3 Terms and definitions 4 Technical requirements 4.1 Environmental conditions 4.2 Access system 4.3 Load properties 4.4 Functional requirements 5 Electrical connection type of thyristor valve 6 Design of thyristor valve 6.1 Electrical design of thyristor valve 6.2 Mechanical design of thyristor valve 6.3 Thermal design of thyristor valve 7 Tests 7.1 Introduction 7.2 Type test and routine test 7.3 Field test Annex A (Normative) Loss calculation method of thyristor valve