高压变压器抗震性能分析的简化动力学模型研究

Study on Simplified Dynamic Models for Seismic Performance Analysis of High‑voltage Transformers

摘要:

高压变压器是高压变电站的关键电气设施，起到为电力网络变换电压和分配电能的作用，其抗震性能是相关电网和供电区域抗震性能和震后恢复能力的重要影响因素。高压变压器主要由油箱体系和升高座与瓷套管体系组成，它们都是地震易损的，需要严格的地震可靠度和易损性等抗震性能分析。目前高压变压器抗震性能分析的常用方法是地震模拟振动台试验和有限元分析，但财物成本或计算费用相当高昂，不适用于地震可靠度和易损性等需要多次地震响应分析的抗震性能分析。为了减少高压变压器单次地震响应分析的成本，本文进行了高压变压器抗震性能的简化分析方法研究，建立了高压变压器地震响应分析的简化动力学模型。该模型将高压变压器分解为油箱体系和升高座?瓷套管体系，油箱体系的加速度响应由油箱顶板的加速度放大系数来简化分析，升高座?瓷套管体系的地震响应由一个考虑升高座和瓷套管摇摆特性的 4 自由度振动系统来简化分析，然后，将油箱体系地震响应和升高座?瓷套管体系地震响应的简化分析模型进行耦合，最终形成高压变压器地震响应的快速计算方法。典型天然地震波作用下某 220 kV 变压器瓷套管顶端位移响应有限元分析结果和简化计算结果的对比分析，验证了本文所建立的简化动力学模型的计算精度。

Abstract:

High-voltage transformers are critical components in high-voltage substations, performing essential voltage transformation and power distribution functions for power grids. Their seismic performance significantly affects the earthquake resistance and post-earthquake recovery capacity of related power grids and power supply areas. High-voltage transformers mainly consist of oil tank system and elevated platform-porcelain bushing system. Both systems are seismically vulnerable, requiring rigorous seismic reliability and vulnerability assessments. Currently, common methods for seismic performance analysis include shaking table tests and finite element analysis. However, their financial costs and computational expenses are relatively high, making them unsuitable for seismic performance analysis that requires multiple seismic response analyses, such as seismic reliability and vulnerability assessments. To reduce the cost of single seismic response analysis for high-voltage transformers, this study investigated simplified analysis methods for their seismic seismic performance and then established a simplified dynamic model for seismic response analysis of high-voltage transformers. The model decomposed the high-voltage transformer into oil tank system and elevated platform-porcelain bushing system. The acceleration response of the oil tank system was simplified using the acceleration amplification factor of the tank roof, and the seismic response of the elevated platform-porcelain bushing system was simplified as a 4-degree-of-freedom vibration system that incorporated their rocking characteristics. Subsequently, the simplified models of both systems were coupled, thereby developing a rapid calculation method for the seismic response of high-voltage transformers. A comparative analysis between finite element analysis results and simplified calculation results for the displacement response at the top of porcelain bushings in a 220 kV transformer under typical natural seismic waves validated the calculation accuracy of the simplified dynamic model established in this study.