In a de-regulated electricity market, finely worked-out operation of utility systems is inevitable to survive in the competitive market. Optimal utility control is also essential for complying with strict environment standards. Utility systems are often composed of many units, such as boilers and turbines and these units are usually characterized with different efficiency curves, which vary with age degrading. Based on these efficiency curves (unit efficiency model), the optimal control system effectively schedules and assigns the proper demand settings for each unit so that minimum energy consumption or cost (or combined evaluation index with energy and money) should be achieved.
Benefits
Toshiba provides for a variety of unit model structures, so almost all utility systems can be easily built up, evaluated, and optimized with actual process data available.
Toshiba has also developed one of the most advanced techniques, for handling highly nonlinear characteristics, found in a turbine's steam-power relation. (Refer to Figure 1)
Details
In Figure 2, optimal control system configuration is presented. Main process values sampled from sensors are collected and transferred to optimizer, where optimization computation is performed in each optimization period, based on units' efficiency models organized in advance. The optimization results are transferred to DCS (Distributed Control System) and each unit in the utility system is optimally operated.
In some legacy system configurations, the optimizer sometimes just output the optimization results on CRT, and then human operators refer the values and set them into the separated DCS. |
