产品概述
LZZBJ9-20/24 电流互感器 这是一款全封闭式柱式电流互感器，专为 20 kV 和 24 kV 交流电力系统设计，适用于最高系统电压为 24 kV 和 27.5 kV 的室内环境。
该电流互感器采用环氧树脂真空浇注工艺制造，具有多伞裙爬电结构，满足24千伏系统的绝缘和爬电距离要求。一次绕组有母线式或穿墙式两种配置，二次绕组则采用漆包铜线绕制。
该产品提供高绝缘性能、高短时热稳定和动稳定电流承受能力以及稳定的精度特性。主要用于电力系统中的电流测量、电能计量、继电保护和信号采集。典型应用包括户内中压 switchgear箱式变电站、配电站和开关站。
产品特点
高绝缘和爬电性能
- Epoxy resin cast insulation: 采用优质环氧树脂真空浇注成型。实心绝缘体内部无气隙，绝缘性能可靠。能够满足24千伏系统运行电压、工频耐受电压和雷电冲击耐受电压的要求。
- Multi-shed creepage structure: 多个外部绝缘子显著增加了爬电距离，有助于满足高海拔或污染环境下 24 kV 系统的绝缘要求，并降低表面闪络的风险。
- 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.
卓越的电气性能
- Wide range of current ratios: 提供多种一次/二次电流比，包括 10/5 A、20/5 A、30/5 A，以及高达 2,000/5 A 的比率。可根据计量和保护要求选择精度等级，包括 0.2S、0.5、5P 和 10P。
- High short-time thermal and dynamic withstand capability: 该变压器能够承受 24 kV 系统中短路故障期间产生的规定短时热电流和动冲击电流。适用于大电流和高短路容量的应用场合。
- Stable accuracy characteristics: 计量绕组提供低且稳定的测量误差，可满足0.2S级高精度电能计量要求。保护绕组提供合适的准确限值系数，以支持可靠的继电器保护运行并降低误跳或拒跳的风险。
结构和安装特点
- 全封闭式柱式结构 一体式压铸结构不包含裸露的带电部件，并提供IP20防护等级。它适用于安装在室内开关设备内，有助于减少灰尘和湿气的侵入。
- Compact modular design: 紧凑的结构占用有限的安装空间，并兼容标准的 24 kV 开关设备布局，支持柜内多回路布置。
- Clearly identified secondary terminals: 次级端子由透明盖板保护，并清晰标记，方便接线。该盖板有助于防止接线错误、短路以及次级电路意外断开。
- Flexible installation: The metal base includes mounting holes for secure bolt installation. The transformer can be installed horizontally or vertically inside indoor switchgear and provides reliable resistance to vibration.
操作与维护特性
- Low-maintenance operation: 环氧树脂浇注体具有高机械强度、抗冲击性和耐老化性。它不含绝缘油，因此没有泄漏风险，有助于减少日常维护需求。
- Wide operating temperature range: The transformer can operate at ambient temperatures from -30°C to +70°C. The epoxy resin maintains stable mechanical and insulation performance under both high- and low-temperature conditions.
- Strong environmental adaptability: 爬电距离和绝缘结构可针对高海拔或相对污染的配电环境进行优化。
技术规格
Typical Electrical Parameters
| 参数 | 规格 |
|---|---|
| 适用系统电压 | 20 千伏/24 千伏 交流电，Um = 24 千伏/27.5 千伏 |
| 额定频率 | 50 赫兹 |
| Rated Primary Current | 10–2,000 A, customizable |
| Rated Secondary Current | 5 A or 1 A |
| Metering Accuracy Class | 0.2秒 / 0.2 / 0.5 |
| Protection Accuracy Class | 5P10 / 10P10 / 5P20 / 10P20 |
| 工频耐压 | 65千伏，持续1分钟，相间和相对地，无击穿 |
| 雷电冲击耐受电压 | 125千伏峰值，无击穿 |
| 局部放电 | ≤10 pC |
| Short-Time Thermal Current (Ith) | 20 times the rated current for 1 second, customizable |
| Dynamic Current (Idyn) | 2.5 times Ith, customizable |
结构和材料参数
| 参数 | 规格 |
|---|---|
| 绝缘介质 | Cast epoxy resin |
| 防护等级 | IP20 |
| Installation Type | 室内柱式螺栓安装 |
| 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 20840.1 | Instrument Transformers—Part 1: General Requirements |
应用
适用电压等级
LZZBJ9-20/24电流互感器适用于20千伏和24千伏交流电力系统室内安装，其最高系统电压分别为24千伏和27.5千伏。
Typical Applications
- 室内 24 千伏中压开关柜中的电流测量、电能计量和继电保护
- Current signal acquisition in box-type substations, distribution stations, and switching stations
- 工矿企业 20 kV 和 24 kV 供电系统
- Commercial buildings and industrial parks
- Current monitoring and control in power automation systems
- 高海拔或相对污染的 24 千伏配电应用
主要功能
电流互感器将高一次侧电流按规定比例转换为标准的5A或1A二次侧电流。
It supplies current signals to:
- Energy meters
- Measuring instruments
- Relay protection devices
- Monitoring equipment
- Control systems
It also provides electrical isolation between the primary and secondary systems, 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 post-type 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 impact
- Non-standard current ratios
- Special accuracy classes
- Non-standard mounting dimensions
安装与维护
安装要求
- Pre-installation inspection:
检查电流互感器，确认浇注体无裂纹、气泡、机械损伤及其他缺陷。检查所有端子标记是否清晰，所供附件是否齐全。核实型号、规格、电流比及准确度等级是否符合设计要求。 - Mounting:
将电流互感器安装在开关柜内指定位置，并用螺栓穿过底座上的安装孔将其固定。确保互感器安装牢固，无松动或移位。安装表面应水平，以避免机械应力不均。 - Primary-side connection:
Connect the primary busbar according to the electrical design. Ensure close contact between the busbar and the primary terminals and tighten all bolts securely to prevent overheating caused by poor contact. - Secondary-side connection:
Connect the secondary winding terminals according to their markings. Metering and protection windings must be connected separately and correctly. The secondary circuit must never be left open while the primary circuit is energized. One point of the secondary circuit must be reliably grounded to prevent hazardous overvoltage. - Insulation inspection:
After installation, measure the insulation resistance between:- Primary and earth
- Secondary and earth
- Primary and secondary
维护要求
- Regularly inspect the epoxy resin body for cracks, mechanical damage, discharge marks, and contamination.
- Check the secondary terminals for looseness, oxidation, or overheating.
- Inspect the external sheds for accumulated dust or contamination.
- Regularly check the primary busbar and secondary wiring for secure connections, overheating, or discoloration.
- 确保二次回路不会意外开路或错误短路。
- 定期测试绝缘电阻和电流比误差，以确认计量和保护精度保持在规定范围内。
- Clean dust, oil, and contamination from the transformer surface and keep the equipment clean and dry.
- 如果检测到开裂、放电、过热或测量误差过大，请立即断电并检查设备。必要时更换电流互感器。
注意事项
- The secondary winding must never be left open while the primary circuit is energized. An open secondary circuit may generate a hazardous overvoltage of several thousand volts, creating a serious risk to equipment and personnel. During maintenance, the secondary winding must be securely short-circuited and grounded.
- 运输和安装过程中，避免与铸体和绝缘裙发生碰撞或接触。机械损伤可能导致环氧树脂开裂，并降低爬电距离和绝缘性能。
- The equipment must be reliably grounded. The grounding terminal on the base 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 | LZZBJ9-20/24 电流互感器 | 24千伏系统中的电流变换和电气隔离主设备 |
| 2 | 安装螺栓和垫圈 | 用于在安装过程中固定电流互感器 |
| 3 | 透明副端子盖 | Protects the secondary terminals and helps prevent incorrect connection or short circuits |
| 4 | Product Instruction Manual | Provides installation, operating, and maintenance guidance |
| 5 | Product Certificate and Factory Test Report | Provides evidence of product quality and performance |
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
该产品已通过适用的型式试验，其性能满足20千伏和24千伏电力系统的运行要求。
