Abstract This paper proposes a hierarchical air balancing control method for the ventilation system, which implements a dual loop PID control loop on a layered system structure. A set of fan-duct PID design methods are proposed, which can be programmed to realize automatic design in microcomputer, including determining the transfer function as a first-order plus time delay model, open-loop characteristic test with two points method and self estimation of PI parameter. The negative open proportional characteristic of the damper is discovered. Based on this fact, the first-order plus time delay mode is used to build the damper transfer function too, and the same estimation method of fan-duct is adopted to estimate the PI parameter. A two-step action way of angle adjustment is presented to avoid the mechanical error and achieve better response characteristics while implementing the damper PID control. The experiments demonstrate that the proposed air balancing method is correct and effective and has the ability to achieve control objectives. Moreover, this method has good adaptability and can be applied to different VAV ventilation system to realize variable air volume control.

中文翻译：

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变风量通风系统分级空气平衡控制方法研究

摘要 本文提出了一种通风系统的分层空气平衡控制方法，该方法在分层的系统结构上实现了双回路PID控制回路。提出了一套可以编程实现微机自动设计的风机风道PID设计方法，包括确定传递函数为一阶加时延模型、两点法开环特性测试和自估计PI 参数。发现了阻尼器的负开比例特性。基于这一事实，同样采用一阶加时延模式建立阻尼器传递函数，并采用与风道相同的估计方法来估计PI参数。提出了一种角度调整的两步动作方式，以在实现阻尼器PID控制的同时避免机械误差并获得更好的响应特性。实验表明，所提出的空气平衡方法是正确有效的，具有达到控制目标的能力。而且，该方法具有良好的适应性，可以应用于不同的VAV通风系统，实现变风量控制。