产品概述
LXK-80–300 零序电流互感器 这是一种环氧树脂浇注式电流互感器，专为室内 10 千伏和 35 千伏交流电力系统设计。
该变压器采用环形磁芯和整体浇注树脂结构，主要用于非有效接地中性点系统中的单相接地故障检测、继电保护和绝缘监测。
它广泛安装在中压 switchgear环网柜、箱式变电站、电缆分支箱等配电设备。该产品是电力系统接地故障保护方案中的关键传感元件。
产品特点
绝缘与电气性能
- Epoxy resin cast insulation:
The transformer is integrally formed using an epoxy resin vacuum-casting process. The solid insulating body contains no internal air gaps and provides excellent dielectric performance. - Oil-free dry-type construction:
The product contains no insulating oil, eliminating the risks of oil leakage, oil contamination, and oil-related fire hazards. It is suitable for indoor oil-free distribution systems. - High-sensitivity zero-sequence current detection:
环形铁芯采用优质叠片硅钢制成，励磁电流低，磁感应度高，能精确检测单相接地故障时产生的零序电流。 - 兼容接地故障保护设备
该变压器可为低电流接地故障选线装置、零序保护继电器、监测装置及其他保护设备提供电流信号。 - 宽光圈范围
内部可用孔径范围为 80 至 300 毫米。不同型号可适应各种三相电缆束或母线排布置，而无需进行重大的安装改造。 - Low partial discharge:
The advanced casting process limits partial discharge to no more than 10 pC, helping reduce insulation ageing and improve long-term operating reliability. - High insulation withstand capability:
该变压器可承受 10 kV 和 35 kV 系统规定的工频耐受电压和雷电冲击耐受电压要求。
结构和安装特点
- Fully enclosed dry-type structure:
磁芯和次级绕组封装在环氧树脂浇注体内部。该产品提供 IP20 防护等级，并且没有暴露的内部带电部件。 - Compact construction:
环形设计占用有限的安装空间，并与标准开关设备和电缆隔间布局兼容。 - Through-aperture design:
三相电缆或母线直接穿过中心孔，无需传统的初级绕组连接即可实现零序电流检测。 - Simplified primary-circuit arrangement:
贯通式结构减少了初级侧连接数量，简化了安装，并有助于最大限度地减少潜在的连接点及相关故障。 - Clearly identified secondary terminals:
二次端子由透明盖板保护，并清晰标记，方便接线。端子布局兼容常见的零序保护回路要求。 - Flexible mounting:
The metal mounting bracket supports secure bolt installation. The transformer can be mounted horizontally or vertically inside indoor switchgear and provides reliable vibration resistance.
操作与维护特性
- Low-maintenance operation:
The dry-type, oil-free structure presents no oil leakage or oil-related fire risk. The epoxy resin body provides high mechanical strength, impact resistance, and ageing resistance. - Wide operating temperature range:
The transformer can operate at ambient temperatures from -30°C to +70°C. The epoxy resin maintains stable insulation and mechanical properties without becoming brittle or deformed. - Stable signal accuracy:
The high-quality silicon steel core and enamelled copper winding provide low operating losses, limited temperature rise, and stable zero-sequence current detection. - Reliable protection performance:
变压器在其额定范围内可承受开关过电压和短路电流的影响，有助于确保可靠的接地故障保护运行。
技术规格
电气参数
| 参数 | 规格 |
|---|---|
| 适用系统电压 | 10千伏/35千伏交流电，最高工作电压=12千伏/40.5千伏 |
| 额定频率 | 50 赫兹 |
| Rated Primary Zero-Sequence Current | Customized according to the system earth-fault current |
| Rated Secondary Current | 5 A or 1 A, customizable |
| Protection Accuracy Class | 10P10 / 10P15, customizable |
| 工频耐压 | 10千伏系统1分钟耐压42千伏；35千伏系统1分钟耐压95千伏，无击穿 |
| 雷电冲击耐受电压 | 10 kV 系统峰值 75 kV；35 kV 系统峰值 185 kV，无击穿 |
| 局部放电 | ≤10 pC |
| 绝缘电阻 | ≥1,000 MΩ between the primary circuit, secondary circuit, and earth |
| Zero-Sequence Current Sensitivity | Detects earth-fault currents of 0.5 A and above; customizable |
结构和材料参数
| 参数 | 规格 |
|---|---|
| 绝缘介质 | Fully cast epoxy resin |
| 防护等级 | IP20 |
| 内径 | 80毫米/100毫米/150毫米/200毫米/300毫米 |
| Installation Type | 室内螺栓安装 |
| 热等级 | Class B, 130°C |
环境参数
| 参数 | 规格 |
|---|---|
| Installation Altitude | ≤2,000 m; high-altitude versions available |
| 工作温度 | -30°C 至 +70°C |
| Storage Temperature | -40°C 至 +85°C |
| 相对湿度 | ≤95%, non-condensing |
适用标准
| Standard | 描述 |
|---|---|
| GB 1208 | Current Transformers |
| GB/T 20840 Series | Instrument Transformers |
| DL/T 866 | Code for Selection and Calculation of Current Transformers and Voltage Transformers |
应用
Applicable Voltage Levels
适用于最高系统电压为12千伏和40.5千伏的室内10千伏和35千伏交流电力系统。
Typical Applications
- 户内中压开关柜的单相接地故障检测与零序保护
- 环网柜
- Box-type substations
- 电缆分支箱
- Distribution stations and switching stations
- 工业与矿山企业中的10千伏和35千伏配电系统
- Commercial buildings and industrial parks
- Low-current earth-fault line-selection systems
- Zero-sequence protection devices
- Earth-fault monitoring for cable and busbar circuits
主要功能
LXK-80–300 检测通过其中心孔的三相电流的矢量和。
Under normal operating conditions, the three-phase current vectors are balanced, and the resulting zero-sequence current is close to zero. When a single-phase earth fault occurs, the current imbalance produces a detectable zero-sequence current signal.
The transformer supplies this signal to:
- Zero-sequence protection relays
- Low-current earth-fault line-selection devices
- Monitoring equipment
- Control systems
- Earth-fault alarm devices
It also provides electrical isolation between the primary power circuit and the secondary protection circuit, helping protect connected equipment and operating personnel.
操作条件
正常运行条件
- Installation altitude: no more than 2,000 m
- Ambient temperature: -30°C to +70°C
- Severe or sudden temperature changes should be avoided
- Relative humidity: no more than 95%, non-condensing
- The environment should be free from corrosive gases
- Flammable or explosive substances are not permitted
- Severe vibration and mechanical impact should be avoided
- Significant dust and salt-spray contamination should be avoided
- Indoor bolt-mounted installation
- Direct sunlight, rain, and condensation should be avoided
Special Operating Conditions
Customized products are required for:
- Installation altitudes above 2,000 m
- Ambient temperatures outside the range of -30°C to +70°C
- Severe pollution or salt-spray environments
- Chemically corrosive environments
- Applications involving strong vibration or mechanical impact
- 非标准光圈直径
- Special sensitivity requirements
- Special protection accuracy classes
安装与维护
安装要求
- Pre-installation inspection:
检查零序电流互感器，确认环氧树脂本体无裂纹、气泡、机械损伤及其他可见缺陷。检查端子标记清晰，所有附件齐全。核实型号、孔径、灵敏度和保护精度符合系统设计要求。 - Mounting:
将变压器放置在开关柜内指定位置，并用螺栓穿过金属支架上的安装孔将其固定。确保变压器安装牢固，无松动或移位。安装表面可以是水平的或垂直的，但不得对铸造体施加不均匀的机械应力。 - Primary conductor installation:
将三根相线朝同一方向穿过中心孔。三相电缆或母线应尽可能同心地穿过孔。避免导体与孔壁直接接触。在安装电缆或母线时，请勿刮伤或损坏孔内的绝缘表面。 - Cable earthing arrangement:
在采用屏蔽电缆的场合，电缆护套接地导体必须按照保护设计进行敷设，以防止零序电流信号的抵消或误判。 - Secondary-side connection:
Connect the secondary terminals to the zero-sequence protection relay or low-current earth-fault line-selection device according to the terminal markings. The secondary circuit must never be left open while the monitored primary circuit is energized. One point of the secondary circuit must be reliably earthed. - Insulation inspection:
After installation, measure the insulation resistance between:- Primary conductors and secondary circuit
- Primary conductors and earth
- Secondary circuit and earth
维护要求
- Regularly inspect the epoxy resin body for cracks, damage, discharge marks, and contamination.
- 检查内部孔径是否有异物、磨损或损坏。
- Inspect the secondary terminals for looseness, oxidation, or abnormal heating.
- 检查三相电缆或汇流排是否与内部孔壁接触或摩擦。
- 确认二次接线保持牢固，并且没有过热或变色的迹象。
- Ensure that the secondary circuit remains closed and reliably earthed.
- Periodically test the insulation resistance and zero-sequence current detection accuracy.
- Verify the correct operation of the connected protection and earth-fault line-selection devices.
- Clean dust and contamination from the transformer surface.
- Keep the aperture free from foreign materials.
- Prevent oil and corrosive substances from contacting the epoxy resin body.
- 如果检测到开裂、放电、过热、测量精度异常或二次回路故障，请立即断开电源并检查设备。必要时更换变压器。
注意事项
- The secondary winding must never be left open while the monitored primary circuit is energized. An open secondary circuit may generate hazardous overvoltage and create a serious risk to equipment and personnel.
- During maintenance, the secondary circuit must be securely short-circuited and earthed before disconnection.
- 运输和安装过程中，避免与环氧树脂本体和内部孔径发生撞击或碰撞。机械损伤可能会降低绝缘性能或改变孔径尺寸。
- 安装电缆或母线时，请勿刮伤孔内的绝缘表面。
- 三相导体必须同向穿过变压器，并且应同心地布置在孔的内部。
- 选择适合电缆束或母线布置外形尺寸的孔径。切勿将过大的导体强行穿过孔径。
- 在运行过程中，防止电缆或汇流排在孔口壁处移动和摩擦，以免损坏绝缘层，造成放电或短路风险。
- The equipment must be reliably earthed. The grounding terminal on the mounting bracket must be securely connected to the switchgear grounding busbar.
- Store the product in a dry, ventilated, and shaded environment. Avoid direct sunlight, high temperatures, moisture, compression, and mechanical impact.
- Installation, commissioning, and maintenance must be carried out by qualified electrical personnel in accordance with applicable electrical safety procedures.
标准供应清单
| 不。 | 物品 | 功能 |
|---|---|---|
| 1 | LXK-80–300 Zero-Sequence Current Transformer | Main device for zero-sequence current transformation, electrical isolation, and signal acquisition |
| 2 | 安装螺栓和垫圈 | Used to secure the transformer during installation |
| 3 | 透明副端子盖 | Protects the secondary terminals and helps prevent incorrect connection or short circuits |
| 4 | Product Instruction Manual | 提供安装、操作、维护和导线布线指南 |
| 5 | Product Certificate and Factory Test Report | 提供产品质量和性能文档，包括比例、准确度和灵敏度测试数据 |
Applicable Standards and Certification
The product complies with the following standards:
- GB 1208, Current Transformers
- GB/T 20840.1, Instrument Transformers—Part 1: General Requirements
- GB/T 20840.2, Instrument Transformers—Part 2: Additional Requirements for Current Transformers
- DL/T 866, Code for Selection and Calculation of Current Transformers and Voltage Transformers
该产品已通过适用的型式试验，其性能满足室内10千伏和35千伏电力系统对地故障保护的要求。
