Modelling and state estimation of power plant steam turbines
Modelling and state estimation of power plant steam turbines
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电厂汽轮机建模与状态估计
DOI：
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发表时间：
1990
期刊：
影响因子：
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通讯作者：
A. Pinkerton
中科院分区：
文献类型：
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作者：
K. Lo;P. Zeng;E. Marchand;A. Pinkerton
基于Levenberg-Marquardt算法和Givens正交行处理技术，提出了一种病态系统的鲁棒状态估计器。该估计器分两个阶段工作：将无平方根的Givens变换应用于测量Jacobian矩阵，将其约简为单位上三角矩阵和对角矩阵的乘积，然后再次使用无平方根的Givens变换来变换对角矩阵，其对角元素等于Levenberg-Marquardt参数。通过调整Levenberg-Marquardt参数，使得二次代价函数的降阶在连续迭代中呈下降趋势，保证了估计量的快速收敛。文中还提出了一种简单易行的可观测性分析算法。给出了无平方根Givens变换的描述和实现。该估计器被应用到一个250 MW，双流，一次再热蒸汽涡轮机，其中有七个给水加热器。测试结果表明，该估计器在较宽的测量误差和测量冗余率范围内具有良好的性能。给出了额定载荷条件下的估算结果示例。在附录中，讨论了涡轮机的建模过程。
The development of a robust state estimator for ill-conditioned systems based upon the Levenberg-Marquardt algorithm in connection with Givens orthogonal row processing technique is described. The estimator works in two stages: the square-root-free Givens transformation is applied to the measurement Jacobian matrix to reduces it to the product of a unit upper triangular matrix and a diagonal matrix, then the square-root-free Givens transformation is again used to transform a diagonal matrix whose diagonal element is equal to the Levenberg-Marquardt parameter. The Levenberg-Marquardt parameter is adjusted so that the reduction in quadratic cost function is downhill in successive iterations and rapid convergence of the estimator is ensured. An observability analysis algorithm is also developed which is simple and easy to implement. Both description and implementation of the square-root-free Givens transformation are presented. The estimator is applied to a 250 MW, double-flow, single reheat steam turbine which has seven feedwater heaters. Tests results show that the estimator performs well under a wide range of measurement errors and measurement redundancy ratios. A sample of estimated results for rated loading condition are presented. In the appendix, the turbine modelling procedure is discussed.