Method for realizing reheat steam temperature multivariable coordinate predictive control through performance indexes

Abstract

The invention discloses a method for realizing reheat steam temperature multivariable coordinate predictive control through performance indexes. According to the method, the reheat steam temperature system of a thermal power generating unit is regarded as a 2*1 multivariable system, a multivariable predictive controller is designed on the basis of novel performance indexes, and the opening degree of a reheat steam temperature reducing water-spray valve and the opening degree of a smoke baffle are controlled simultaneously. In the performance indexes, on one hand, an algorithm is simplified and rapid control is realized on the basis of requirements on a single-step prediction error and a prediction error change rate, and the control performance of a control system can also be effectively adjusted by adjusting a predictive length and a predictive error change rate weight; on the other hand, dynamic limit on the opening degree of the temperature reducing water-spray valve is added in the indexes, the part of the performance parameters is self-adaptive to changes during a control process, and the amount of temperature reducing water sprayed in reheat steam can be reduced while a reheat steam control quality is improved, thus effectively increasing the cycle efficiency of the unit.

Description

technical field [0001] The invention belongs to the technical field of thermal automatic control, and in particular relates to a method for realizing multivariable coordinated predictive control of reheating steam temperature through performance indicators. Background technique [0002] The reheat steam temperature is an important parameter in the thermodynamic system of a thermal power plant. The quality of reheat steam temperature control directly affects the safe and economical operation of the entire unit. The reheat steam temperature control system is one of the important control systems of the unit. However, regardless of the steam side control or the flue gas side control, the reheat steam temperature object has a large delay and inertia, and the reheat steam temperature is difficult to control. At present, considering the poor controllability and accuracy of the flue gas baffle adjustment, two independent PID controllers are generally used to realize the adjustment o...

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Problems solved by technology

[0004] Purpose of the invention: Aiming at the above problems, a method for realizing multi-variable coordinated predictive control of reheat steam temperature through performance indicators is proposed, which can solve the problem of large dynamic and static deviations in reheat steam temperature adjustment, and the water injection volume on the steam side cannot be optimized, which affects the economical efficiency of the unit. , and ordinary predictive control has a large amount of calculation, cannot realize online control, lacks effective control parameters to adjust the performance of the control system, etc.

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