电磁接触器多变量反馈吸持控制策略的研究

The Multivariate Feedback Control Strategy for Electromagnetic Contactor Holding

该文针对单一电流闭环控制引起的电磁接触器吸持高频噪音以及无法自适应调节吸持参考电流等问题,提出多变量反馈控制思路:通过分析线圈电流强迫上升现象的约束条件,建立铁心分离反馈变量,改变依赖本体结构、预先设定吸持电流参考的现有控制模式,自动获取接触器当前工况下的临界吸持电流,适应本体参数和工作环境的变化,对接触器智能控制具有普遍意义;引入母线电压前馈变量,以电流反馈为内环推导了闭环占空比的控制规律,验证控制规律的闭环稳定性,有效减小了线圈电流纹波及谐波,抑制铁心振动幅值,降低高频噪音;为实现多变量反馈控制策略,设计一种新型的四工作模态接触器控制拓扑,对去磁回路进行动态组合,在宽电压范围内缩短接触器吸持到分断的动作延时。相关仿真及实验验证了控制策略的有效性。

In order to solve the problem of high frequency acoustic noise and disability to adjust reference current adaptively when electromagnetic contactors hold with single current feedback control, the multivariate feedback control strategy was proposed. The constraints of forced current rise was analyzed and the feedback variable was established to indicate iron core opening. Thus critical current for holding was automatically found to adapt to parameter variation of contactors and work environment. This idea has general meaning to intelligent control for contactors and changes existing control mode in which the holding current is set beforehand and relies on mechanical structure. The bus voltage feedforward was imported into closed current loop to infer closed-loop duty law. The law is verified its stability for reducing current ripple and harmonic. As result, vibration amplitude and high frequency noise are effectively controlled.A novel control topology with four operation modes, was designed for performing multivariate feedback control strategy.And dynamic combination of demagnetization shortens the time delay when contactors operate from holding to opening under wide range of voltage. Related simulation and experiment prove the effectiveness of the proposed strategy.