Xinhai Power Co., Ltd. 200MW Unit The Digital Hydraulic DEH Technology Program Design And Implementation

Along with the national economy fast development, the society has much more demands for theelectric power, and also sets a higher request for the electrical energy quality and the electricitygeneration cost. Because the electric power cannot be stored up and has the timely characteristic, thepower plant must adapt to the demands of exterior users promptly. Meanwhile in order to guarantee thestability of the entire electrical network, a higher requirement is set for the steam turbine velocitymodulation system.The velocity modulation system of the single set capacity in 200MW in out country is basically themechanical hydraulic pressure type velocity modulation system. It has not been able to adapt tocoordination control system (CCS) and the electrical network automatic electricity generation controlfunction (AGC). And the adjustment system also has the disadvantages of the joint dead-bands, badadjustment quality and disability of realizing valve management. It threatens the unit and the electricalnetwork security seriously, and brings a great deal of inconveniences to the end-users. Therefore thetransformation to the mechanical hydraulic pressure type velocity modulation system appears urgent.Advanced digital electrical hydraulic pressure system (DEH) is flexible to various control tactics andable to satisfy the request of the modern steam turbine control system. In the aspects of the systemsecurity and reliability, the DEH has achieved the request of the power plant. This article has analyzedeach kind of current transformation plan in or out of China, and pointed out the advantages anddisadvantages of each transformation plan. According to the actual running of original 200MW unit'stiming system of xinhai Electricity Generation Co. Ltd, the feasibility to apply DEH in No. 11 unit ofxinhai Electricity Generation Co. Ltd has been drawn.Through analysis and research of the experimental data after transformation, it is feasible to apply thedigital-hydraulic controlling system to replace the existing mechanical hydraulic controlling system.And such application can achieve the anticipated goal, show its practical value and significance, andprovide a new thought for the Turbine Generator Control System transformation.