Recursive Subspace-based Model Refinement Method for Digital Twin of Thermal Power Unit

doi:10.16182/j.issn1004731x.joss.22-0989

Abstract

Abstract:

Due to factors such as simplified assumptions or equipment characteristic deviation, modeling errors are inevitable in the mechanism modeling of thermal power units. To deal with the problem, this paper proposes a novel model refinement method based on recursive subspace for the digital twin of thermal power units. Firstly, the digital twin models are built based on mechanism analysis and combined with small sample data of typical conditions, ensuring interpretability and generalization performance. Secondly, based on the recursive subspace identification method, the refinement model is built and updated online in real time to compensate for the modeling error, improving the prediction accuracy and ensuring the high fidelity of the overall digital twin model. Finally, simulation results validate the effectiveness of the proposed method.

Key words: digital twin, thermal power unit, model refinement, subspace identification, data driven

CLC Number:

TP391.9

Zhao Yanbo, Cai Yuanli, Hu Huaizhong. Recursive Subspace-based Model Refinement Method for Digital Twin of Thermal Power Unit[J]. Journal of System Simulation, 2024, 36(1): 195-202.

Figures/Tables 14

Table 1

Definitions of variables

变量	释义
$W g$	给煤量
$μ h p c$	主蒸汽阀门开度
$P h p c$	主蒸汽压力
$P w$	输出功率
$T w$	水冷壁惯性时间常数
$T B$	锅炉惯性时间常数
$K D$	汽包比例系数
$K u$	汽包到过热器泄流系数
$K B$	锅炉比例系数
$T D$	汽包惯性时间常数
$K H$	高压缸比例增益
$K I$	中压缸比例增益
$K L$	低压缸比例增益
$T H$	高压缸惯性时间常数
$T I$	中压缸惯性时间常数
$T L$	低压缸惯性时间常数
$K q$	锅炉入口热量修正系数
$Q n e t, a r$	燃煤低位发热量

Table 1

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EI	主蒸汽压力(MPa)				误差降幅(%)
EI	NOMR	SMR	ANNMR	RSMR	SMR	ANNMR	RSMR
EA	0.004 0	0.000 7	0.000 6	0.000 1	82.5	85.0	97.6
EMAX	0.004 7	0.001 3	0.001 4	0.000 3	72.3	70.2	93.6

EI	输出功率/MW				误差降幅/%
EI	NOMR	SMR	ANNMR	RSMR	SMR	ANNMR	RSMR
EA	4.722 5	0.678 4	0.740 7	0.402 8	85.6	84.3	91.5
EMAX	5.186 2	0.950 2	1.211 0	0.532 0	81.7	76.7	89.7

EI	主蒸汽压力/MPa				误差降幅/%
EI	NOMR	SMR	ANNMR	RSMR	SMR	ANNMR	RSMR
EA	0.004 0	0.001 1	0.000 7	0.000 3	72.5	82.5	92.9
EMAX	0.005 5	0.002 5	0.001 6	0.000 7	54.6	70.9	87.3

EI	输出功率/MW				误差降幅/%
EI	NOMR	SMR	ANNMR	RSMR	SMR	ANNMR	RSMR
EA	5.278 8	0.749 3	0.263 0	0.137 2	85.8	95.0	97.4
EMAX	5.686 7	0.806 7	0.679 3	0.192 8	85.8	88.1	96.6

EI	主蒸汽压力/MPa				误差降幅/%
EI	NOMR	SMR	ANNMR	RSMR	SMR	ANNMR	RSMR
EA	0.004 2	0.001 6	0.001 6	0.000 1	61.9	61.9	97.6
EMAX	0.008 1	0.002 2	0.002 5	0.000 4	72.8	69.1	95.1