Deliang Zeng

Dynamic model for controller design of condensate throttling systems.

Improving the load adjustment rate of coal-fired power plants in China is very important because of grid load fluctuations and the construction of new large-scale power plants connected to the countrys power grid. In this paper, a new application of condensate throttling system for rapid load adjustment is proposed on the basis of the characteristics of turbine-stored energy. To ensure effective and safe operation of the condensate throttling system, a non-linear control model is derived through reasonable simplifications of fundamental physical laws, and the model parameters are identified using experimental data from a 660 MW supercritical coal-fired power plant. The model outputs are compared with actual measured data for different unit loads. Results show that the established models responses strongly correlate with the actual units responses and can be used for controller design.

Soft-sensing model of oxygen content based on data fusion

The soft-sensing technique of oxygen content in flue gases based on data fusion is presented according to the high first cost of conventional oxygen content analyzers, their high maintenance expenses and low durability. Through the mechanism analysis and the statistical analysis of a number of data, soft-sensing models of oxygen content and air flow. etc. are set up. Based on multisensor data fusion, more reliable and accurate values of input data are obtained. At last, this soft-sensing model fit well with the practical oxygen content, which is illustrated by the simulations.

Genetic algorithm-based multi-variables nonlinear boiler model identification for 300 MW power unit

A kind of improve genetic algorithm for identifying multi-variables nonlinear boiler model of 300 MW power unit is introduced. In the algorithm, floating-point coding, rank-based selection, elitist reservation and grouping method are used, and the premature convergence is restrained, and the searching ability is improved. The genetic algorithm-based model identification MATLAB program is designed and the model parameters can be gotten with it according to the operating data log files. It is shown by simulation research that the multi-variables nonlinear model can be identified accurately no matter what kind of input signal is used.

A Non-Linear Dynamic Model of Second Air System in Power Plant and a New Control Method Design

In this paper, we present a nonlinear dynamic model of second air system. This model is constructed by means of mechanism and statistical analysis. Simulations show that it fits well to the practical process output. Then two disturbance experiments are made on this model to analysis the dynamic response performance of second air system. In order to resolve the coupling between the airflow and air pressure, coordinated control system of second air system is designed. Simulation results compared with other control method show that our approach could obtain good control quality

Coordinated control of once-through boiler-turbine units using feedforward-feedback approach based on stable inversion

The structural features of the once-through boiler-turbine unit are nonlinear, strong coupling and multi-parameter, which affect the response ability of load of its coordinated control system. In order to improve the control performance of the once-through boiler-turbine coordinated system, a control method of feedforward-feedback control based on the nonlinear model of the once-through boiler-turbine unit was proposed in this article. First a nonlinear model that has certain accuracy and is fit for the controller design was established after reasonable reduce. Then the theory of stable inversion was introduced to seek the inversion solution of the nonlinear model. Feedforward control via inversion system leads the outputs of unit to the set points rapidly, while the feedback controller is designed for multivariable outputs to remove the tracking errors caused by external interference. Finally, simulation tests of the state disturbance and set point perturbation in different static operating conditions were carried out. Simulation results verify that the outputs of feedforward-feedback control method can track the set points accurately and fast.