Часто задаваемые вопросы (Часто задаваемые вопросы)

What is the primary purpose of Non-Gapped Line Arresters (NGLA)?

NGLAs are designed to prevent flashovers on overhead line insulator strings, not to protect the insulators themselves. Their main function is to reduce or eliminate lightning-induced outages that could impact network stability and have contractual consequences.

How do NGLAs differ from substation arresters?

While substation arresters protect valuable assets like power transformers from financial damage, NGLAs specifically focus on preventing flashovers on transmission line insulators. They are mounted on towers or near insulators to handle lightning and switching surge overvoltages.

Do NGLAs need to be installed on every tower?

Installation on every tower is usually not cost-effective except in cases where line tripping consequences are particularly harmful to the system. The number of NGLAs depends on tower footing resistance and outage reduction targets.

What are the mounting considerations for NGLAs?

NGLAs face higher physical stress than other arresters due to exposure to elements. They must withstand vibration, ветер, torque, and impact stress. Mounting requirements are unique to each tower configuration and require careful consideration.

What determines the AC rating selection for NGLAs?

The Maximum Continuous Operating Voltage (MCOV) must be checked for temporary overvoltage withstand capability. The initial AC rating is generally a minimum value that may need to be increased to meet system constraints.

How does the presence of shield wires affect NGLA selection?

Systems without shield wires require NGLAs with higher charge capabilities due to increased risk of direct lightning strikes. Shield wire systems allow for lower charge requirements as lightning strokes are shared between arresters.

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