| 摘要 |
PURPOSE:To control the control target value with a good following property even if it is fluctuated frequently, by comparing the target value with a measured value through the delay generating part of a characteristic approximating the characteristic of the system to be controlled. CONSTITUTION:The explanation is described hereunder on a basis of the oxygen quantity supply control device in the boiler. Converting part 21 converts gaseous oxygen concentration signal 106 in waste gas to air ratio momega. Converting part 22 receives fuel quantity signal 104 and converts it to a theoretical air ratio which the burner requires, and the output is sent to comparing part 24 through delay generating part 23 to obtain measured excess air rate muomega. It is difficult that the characteristic of delay generating part 23 coincides with that of the system to be controlled through the characteristic of delay generating part 23 approximating that of the system to be controlled, and therefore, measured excess air rate muomega is output through delay compensating part 25 and is compared with target excess air rate mus by comparing part 26, and the air quantity for fuel is controlled through proportional integral controller 27 and limiter 28. |
