The Application Of MAX1000 And Analyse Of CCS Control Strategy In 125MW Generating Unit

In the middle of 1990s,with the increasing requirements of automation and reliability in power plant from electricity net and the spread of work in depletion of numbers and increasing efficiency and saving power and deducing wastage, there is much limitation in many medium scale thermal power units in the range of 100-200MW for the purpose of demand of electricity net and of secure operation. In this paper, aiming at old equipments and low automatic shift rate in addition to coordinated control system not being put into, the distributed control system MAX1000 is introduced into the NO.7 unit.This work introduces hard wares structure and function, explicates the principle of CCS based on direct energy balance, and then describes all kinds of subsystems, at last there are many online tests on MAX1000. After the project completed, the operating data can be well adopted, turbine and boil can be coordinated and operating personnel's labor intensity could be reduced, which will take an active role in increasing benefit. Furthermore, after DCS and MIS connected, the managers can know the status at any moment, that promotes the level of management.L&N Company is developing CCS based on direct energy balance concept, and then nowadays it is the fourth unit control strategy. DEB/400 can change turbine running status independently while continue keeping the balance between turbine and boiler in urgent time or under the requirement of design, besides keeping turbine and boiler stable status. So, it has remarkably superiority on rapidly adaptation to load demand and on overcoming inner disturbance, thus it is a better scheme compared with all CCS at present. In addition, this paper gives a brief introduction about some advanced control methods, such as decoupling, pole configuration, INA method, model pre-control, fuzzy control and inner model control, applied to multi variants control system. Because all variants are not of the same importance in multi variants control system of pyrological process, unilateral decoupling method can meet the need of control.DEB coordinated control system is a synthetical control strategy in term of a lot of practical experience and profound analysis of unit generator running mechanism, it can not only resolve the stability of overall running situation and overall balance situation and stabilize main steam pressure, but also greatly promote adaptability of load rapidtrack, as a result, it is the basis and core of unit generator automation. Moreover, from insuring the start of harmonizing operation with the energy balance between turbine and boiler to coordinating all key control loop, and from normal operation status to coordination between abnormal status and start or stop status, this coordinated control strategy accords with the natural rules of unit generator running, and it is good for keeping equipments healthy, prolonging life-span and holding optimal operation status, so there is obvious benefit.Practice proves that DCS altered possesses strong functions, advanced structure and high specific performance and price, and the system put into operation contributes essentially to safe and stable and economic operation. Reliability and stability of the system both have been greatly increased and regulating quality also gets improvement, therefore, the overall unit's alteration is feasible and successful, and in future the system will perform better through further perfecting.