针对传统BP神经网络在线估算锂离子电池健康状态(state of health,SOH)容易使权值陷入局部最优解,导致SOH预测不精确。结合模拟退火(simulate anneal,SA)算法能有效收敛于全局最优的特点,提出一种基于SA算法优化BP神经网络的锂离子电池...针对传统BP神经网络在线估算锂离子电池健康状态(state of health,SOH)容易使权值陷入局部最优解,导致SOH预测不精确。结合模拟退火(simulate anneal,SA)算法能有效收敛于全局最优的特点,提出一种基于SA算法优化BP神经网络的锂离子电池SOH在线预测方法。以锂离子电池为研究对象,分析了微分电压、欧姆内阻、循环次数与电池SOH的关系,并以此作为电池的健康状态因子(health indicator,HI)输入至BP神经网络。利用SA算法优化BP神经网络的权值,使预测模型得到最优解。实验结果表明:利用优化算法对电池SOH进行预测,其最大误差仅为1.98%,平均误差为1.09%。相较于传统BP神经网络,优化算法预测最大误差降低了5.62%,平均误差降低2.33%。从而验证了基于SA算法优化BP神经网络能够获取全局最优值并提高电池SOH估算精度是有效的。展开更多
An optical 90° hybrid based on an InP 4 × 4 multimode interference (MMI) coupler is designed and fabricated for the application in a coherent receiver.It reveals that the width of multimode waveguide is the ...An optical 90° hybrid based on an InP 4 × 4 multimode interference (MMI) coupler is designed and fabricated for the application in a coherent receiver.It reveals that the width of multimode waveguide is the most critical parameter for the devices,and the multimode waveguide width can be accurately controlled within 0.1 μm in our experiments.Across the entire C-band (1527-1561 nm),the maximum imbalance of the devices is less than 0.7dB,and the common mode rejection ratios for in-phase channels and quadrature channels are better than - 24 dB.展开更多
文摘针对传统BP神经网络在线估算锂离子电池健康状态(state of health,SOH)容易使权值陷入局部最优解,导致SOH预测不精确。结合模拟退火(simulate anneal,SA)算法能有效收敛于全局最优的特点,提出一种基于SA算法优化BP神经网络的锂离子电池SOH在线预测方法。以锂离子电池为研究对象,分析了微分电压、欧姆内阻、循环次数与电池SOH的关系,并以此作为电池的健康状态因子(health indicator,HI)输入至BP神经网络。利用SA算法优化BP神经网络的权值,使预测模型得到最优解。实验结果表明:利用优化算法对电池SOH进行预测,其最大误差仅为1.98%,平均误差为1.09%。相较于传统BP神经网络,优化算法预测最大误差降低了5.62%,平均误差降低2.33%。从而验证了基于SA算法优化BP神经网络能够获取全局最优值并提高电池SOH估算精度是有效的。
基金Supported by the National Natural Science Foundation of China under Grant No 61076042the Special Project on Development of National Key Scientific Instruments and Equipment of China under Grant No 2011YQ16000205+3 种基金the National Key Technology R&D Program of China under Grant No 2009BAH49B01the National High Technology Research and Development Program(863 Program)of China under Grant Nos 2011AA03A106 and 2011AA010304,Science and Technology Special Project in Hubei Province(No 2009AAA009)the Natural Science Foundation of Hubei Province(No 2010CDB01606)the Research Funds for the Central Universities(HUST No 2011QN036).
文摘An optical 90° hybrid based on an InP 4 × 4 multimode interference (MMI) coupler is designed and fabricated for the application in a coherent receiver.It reveals that the width of multimode waveguide is the most critical parameter for the devices,and the multimode waveguide width can be accurately controlled within 0.1 μm in our experiments.Across the entire C-band (1527-1561 nm),the maximum imbalance of the devices is less than 0.7dB,and the common mode rejection ratios for in-phase channels and quadrature channels are better than - 24 dB.
