基于随机过程的飞轮储能系统动态可靠性分析

With the increase of energy density and rotating speed of flywheel energy storage system (FWESS), reliability and safety has become the key problem of FWESS development. By taking reflecting the uncertainty of the acting time and amplitude of loads and the uncertainty of FWESS structure parameters on the failure rate of FWESS as its main goal, a method to evaluate the dynamic reliability of FWESS based on stochastic process is proposed. Poisson process and maximum entropy are adopted to describe the two dimensional uncertainty of loads on acting time and amplitude. The loss analysis and thermal analysis platform is established to obtain the stress, thermal, electromagnetic coupled fields on key components, and then their thermo-elastic fatigue reliability model is set up, based on which, the predictive lifetime of key components is estimated based on Palmgren-Miner linear accumulative damage rule and P-S-N curve. The failure mechanism, including electricity leakage failure, thermal fatigue, and mechanical fatigue of isolation systems is analyzed to establish its reliability evaluation model. Finally, the dynamic balance model of the lifetime of key components was set up based on effective lifetime analysis, which to balance the effective lifetime of key components.

随着飞轮储能系统（FWESS）能量密度和转速要求的日益提高，可靠性和安全性将成为FWESS开发过程中的核心问题。本项目以反映用电载荷时间及幅值及其自身结构的不确定性对FWESS失效率的影响为目标，提出基于随机过程的FWESS动态可靠性评估方法。采用泊松过程和最大熵原理描述用电载荷时间和幅值的二维不确定度；建立FWESS损耗分析与热传导分析平台，得到飞轮储能系统的电磁场温度场力场耦合模型，分析关键部件的热弹耦合疲劳可靠性，根据Palmgren-Miner 线性累积损伤法则和部件的P-S-N 曲线，估算关键部件的疲劳寿命；开展绝缘结构的漏电失效、热疲劳和机械疲劳失效机理分析，得到绝缘结构的可靠性评估模型。最后，建立基于有效寿命的FWESS关键部件寿命动态均衡数学模型，使得FWESS各关键部件的有效工作寿命趋于均衡。

飞轮储能具有储能密度高、功率密度大、具备短时内输出更大能量的特点，在分布式发电、智能电网、交通机车等领域应用广泛。对于便携式和移动式的飞轮储能系统（如车载系统），其功率密度和能量密度是其核心指标。飞轮储能系统由于其高转速和大功率特性，是典型的安全苛求系统，其可靠性与安全性问题是提高其功率密度和能量密度新的挑战。飞轮储能系统载荷的随机性与其可靠性的动态性是其可靠性分析中面临的新的问题。本项目依据飞轮储能系统的故障模式建立了其故障树，提出了用于飞轮储能系统的永磁同步电机及飞轮本体的设计方案，对关键部件如电机保护套、永磁体的静强度可靠性进行了分析；基于Palmgren-Miner 线性累积损伤法则和部件的P-S-N 曲线提出了飞轮储能系统高速轴系的设计方法、模态分析以及疲劳可靠性分析方法；提出了周期性检测条件下基于随机过程的主轴寿命预测及最优视情维修策略。分析了电机的温度场分布，确定了电机绝缘的温度载荷，提出了绝缘热老化的加速寿命评估方法，最终提出了基于寿命分布与时间延迟模型的的电机绝缘寿命预测方法。本项目共发表论文6篇，SCI论文3篇，EI及核心期刊论文3篇，培养研究生3名，完成了项目预期目标。