A stable control method for the rotational speed of an axial flow fan

Abstract

The invention belongs to a control technology for a medium-power axial flow fan and relates to a stable control method for the rotating speed of the axial flow fan. According to the scheme adopted by the invention, the stable control method comprises the following steps: carrying out logic synthesis through utilizing three pulse signals with a difference of 60-degree electric angle among each other, which are output by an axial flow fan position sensor, so as to obtain a speed feedback signal Speed-FB; capturing a count difference between the adjacent hop edges of the Speed-FB signal so as to obtain the frequency f of the Speed-FB, and further obtaining the rotating speed digital signal Speed of the axial flow fan; carrying out a window filtering process with sum and average filtering compensation on the Speed to obtain a real-time rotating speed Speed-BH required by closed loop control; finally adopting a BANG-BANG control algorithm to realize closed loop stable control on the rotating speed of the axial flow fan. The stable control method realizes stable soft starting and precise speed control on the axial flow fan, reduces pulses in the transient corresponding process of the axial flow fan and reduces noise in the running process.

Description

technical field

[0001] The invention belongs to the control technology of a medium-power axial-flow fan, and relates to a method for controlling the rotational speed of an axial-flow fan. Background technique

[0002] Axial flow fan is a general-purpose mechanical product widely used in the industrial field. It consumes a lot of power. The axial flow fan system that adopts automatic speed regulation and then adjusts the air volume can not only realize intelligence, but also have obvious power saving benefits. The Ministry of Finance also encourages The use of this kind of axial flow fan. However, traditional axial flow fans use asynchronous axial flow fans and inverters to realize speed regulation control. The inverter directly operates the power supply and controls the speed by changing the frequency. It is very difficult to achieve stepless speed regulation. In the process of state response, the speed control effect is poor, it is obviously affected by the load, and the p...