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
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
直流融冰裝置 第2部分：晶閘管閥
1 范圍
GB/T 31487的本部分規定了直流融冰裝置晶閘管閥的功能、設計和試驗等的基本要求。
本部分適用于直流融冰裝置水冷卻晶閘管閥，采用其他冷卻方式的晶閘管閥可參照本部分。
2 規范性引用文件
下列文件對于本文件的應用是必不可少的。凡是注日期的引用文件，僅注日期的版本適用于本文件。凡是不注日期的引用文件，其最新版本(包括所有的修改單)適用于本文件。
GB/T 3859.1—2013 半導體變流器 通用要求和電網換相變流器 第1-1部分：基本要求規范
GB/T 13498 高壓直流輸電術語
GB/T 16927.1 高壓試驗技術 第1部分：一般定義及試驗要求
GB/T 20990.1—2007高壓直流輸電晶閘管閥 第1部分：電氣試驗
GB 50150—2006 電氣裝置安裝工程 電氣設備交接試驗標準
IEC/TS 60815-1：2008 污染環境中所用高壓絕緣子的選擇和尺寸測定 第1部分：定義、信息和一般原理(Selection dimensioning of high-voltage insulators intended fuse in polluted conditions—Part 1：Definitions，information general principles)
IEC 61803：2011 采用電網換相換流器的高壓直流(HVDC)換流站功率損耗的確定[Determination of power losses in high-voltage direct current (HVDC) converter stations with line-commutated converters]
3 術語和定義
GB/T 13498界定的以及下列術語和定義適用于本文件。
3.1
閥 valve
由電力電子器件及輔助部件組成的電氣和機械聯合體，能實現單向或者雙向導通。
注：目前常用的閥有二極管閥、晶閘管閥、絕緣柵雙極晶體管(IGBT)閥等。
3.2
晶閘管閥 thyristor valve
電力電子器件為晶閘管的閥。
3.3
換流器 converter
能實現完整換流功能的電氣裝置。
3.4
單閥 single valve
由若干個晶閘管級串聯組成，是6脈波換流器的一個臂。
3.5
晶閘管級 thyristor level
閥的部件，由一個晶閘管或若干并聯的晶閘管與緊靠它們的輔助設備構成。
3.6
閥電子電路 valve electronics
在閥電位上執行控制、監測和保護功能的電子電路。
3.7
閥基電子單元 valve base electronics
提供地電位控制設備與閥電子電路或閥裝置之間接口的電子設備，又稱閥接口電子設備。
3.8
觸發角 firing angle
從理想正弦換相電壓正向過零點至正向電流導通開始時刻的時間，以電角度度量。
3.9
額定直流電流 rated direct current
按規定的負載條件和使用條件，換流器輸出的直流電流(平均值)。
3.10
最大直流電流 maximum direct current
換流器在規定的運行條件下，(理論上可在無限時間內)向負載輸出的最大直流電流。
注：一般在不同冷卻媒質和環境溫度下有不同值。
3.11
2h過載直流電流 2h overload direct current
換流器在規定的2h內，能向負載輸出的直流電流。
注：一般在不同冷卻媒質和環境溫度下有不同值。
3.12
最大理想空載直流電壓 maximum ideal no-load direct voltage
一般指換流器在空載情況下的最大直流電壓(Udi0max)。
注：此時，將各種電壓降和電網電壓波動的因素忽略不計。
3.13
額定直流電壓 rated direct voltage
在規定條件下，換流器輸出的直流電壓應達到的平均值。
3.14
額定直流功率 rated direct power
換流器額定直流電壓與額定直流電流之積。
3.15
均流系數 coefficient of current distribution
直流融冰裝置晶閘管閥采用雙橋并聯型式時，并聯運行支路電流的平均值與最大支路電流值之比。
3.16
額定結溫 rated junction temperature
晶閘管正常工作允許的最高結溫。
3.17
大角度大電流運行 large angle and high current operation
直流融冰裝置輸出額定直流電流且觸發角近似90°的運行方式。
3.18
零功率試驗 zero power test
直流融冰裝置直流側經電抗器短接，將直流電流升至設定值，檢查直流融冰裝置直流電流控制功能及電流承受能力。
4 技術要求
4.1 環境條件
直流融冰裝置晶閘管閥正常使用環境條件包括以下方面：
a)海拔小于2000m；
b)環境溫度不低于－20℃，不高于50℃；
c)相對濕度最大值為85％(20℃以下時)；
d)污穢等級為b級；
e)地震震級，不超過8級；
f)交流電網頻率波動范圍不超過±5％。
注1：當海拔高度大于2000m時，應根據相關標準進行海拔修正設計。
注2：戶外污穢等級，在設計時，一般按照IEC/TS 60815-1：2008中的d級考慮。
4.2 接入系統
直流融冰裝置換流器宜通過專用換流變壓器或者換相電抗器接在滿足融冰容量要求的主變壓器低壓側(10kV或35kV側)，也可與主變壓器低壓側直接連接。否則，應通過專用變壓器接在上一級電源母線上。
4.3 負載性質
直流融冰裝置換流器的負載，主要是不同規格和不同長度的架空導線、架空地線、光纖復合地線(OPGW)、電抗器及其組合。
對直流融冰兼靜止無功補償裝置換流器，在靜止無功補償模式下為三相交流電壓控制電路，負載為電抗器。
4.4 功能要求
4.4.1 輸出直流電流的范圍
直流融冰裝置換流器輸出的直流電流，在穩定運行時，允許選擇從設計要求最小值到最大電流之間的任意電流值。
4.4.2 輸出直流電流的偏差
直流融冰裝置換流器輸出的直流電流，在穩定運行時，其輸出電流的偏差應在目標設定值的±5％以內。
4.4.3 輸出直流電壓的要求
直流融冰裝置換流器輸出的直流電壓應滿足設計要求。
4.4.4 輸出電流的斷續要求
在電流較小的情況下，直流融冰裝置晶閘管閥的輸出電流可能出現斷續的情況。如果每周波電流斷續的次數少于6次，晶閘管閥應能短時間運行(至少10min)。一般情況下應加裝平波電抗器以保證零功率試驗和架空地線(或光纖復合地線OPGW)融冰等工況下的電流連續。
4.4.5 大角度大電流運行的要求
直流融冰裝置晶閘管閥應允許在大電流大角度方式下持續穩定運行。在輸出直流電流達到額定電流，觸發角度近似90°的工況下，連續運行時間大于2h。
4.4.6 工作于靜止無功補償模式的要求
對直流融冰兼靜止無功補償裝置，晶閘管閥需要滿足直流融冰和靜止無功補償兩種運行模式的要求。
5 晶閘管閥的電氣聯結型式
直流融冰裝置晶閘管閥的電氣聯結型式為6脈波換流器或12脈波換流器。12脈波換流器由兩組6脈波換流器串聯或者并聯組成。6脈波換流器每相的臂稱為單閥。
為了滿足電能質量的要求，減少直流融冰裝置運行對供電系統的影響，在將兩組6脈波換流器串聯或并聯時，閥側繞組間的相位(角)差應為30°，以構成12脈波換流器。
6脈波換流器如圖1所示，兩組6脈波換流器串聯構成的12脈波換流器如圖2a)所示，兩組6脈波換流器并聯構成的12脈波換流器如圖2b)所示。
