Abstract With the extensive use of AC contactors, energy consumption has become a problem that cannot be ignored, in which the coil holding energy consumption is the main source. In order to reduce the energy consumption, the reference value of the holding voltage or current must be as low as possible, and the control system should have the adaptive adjustment function to ensure that the effectiveness of the control is not affected by the aging of the AC contactor or the change of the mechanism characteristics. The closed-loop control mode with coil current feedback can effectively avoid the unreliable holding problem caused by temperature rise by controlling the duty cycle of the coil voltage in real time to keep the coil current at a constant value. However, the closed loop control mode usually uses several times of the critical holding current as the reference value, which will cause additional energy consumption and cannot achieve energy-saving operation in real sense. At the same time, the switching electronic devices in the coil excitation circuit need to be on and off constantly, that will bring additional switching losses. Consequently, giving consideration to both reliable holding and energy saving has become the research focus of holding process control. This paper proposes an adaptive holding control strategy based on multiple feedback parameters, which make the contactor have high holding stability even under low holding current. Through theoretical derivation, simulation and experiment, this paper analyzes the change rule of induced electromotive force when unreliable holding event occurs, and draws the conclusion that the generation of induced electromotive force is almost synchronous with the occurrence of unreliable holding events, and the time interval from the occurrence of induced electromotive force to the contacts breaking is more than 10ms. During this period of time, it is sufficient for secondary control of the contactor. The topology control circuit of the contactor coil is designed, which can adaptively adjust the holding voltage by using the numerical control switching power supply to meet the needs of AC contactor starting and adaptive holding in the closed-loop control mode. Taking coil current, contact current and coil induced electromotive force as feedback parameters, an adaptive holding control strategy for AC contactors based on multiple feedback parameters is proposed. Under normal conditions, the contact current and coil current are used as basic feedback parameters to adaptively adjust the holding voltage. If the moving iron core and the static one are separated abnormally, an induced electromotive force of the coil will be generated. When the induced electromotive force reaches a certain threshold, it will be detected by the single chip microcomputer in the control circuit. At this time, the coil is excited strongly by the circuit to make the moving iron core close again to ensure the reliability of the holding. Based on the control strategy, the control module is designed and tested. The results show that the control module can achieve the following functions. ① When the contact current increases, the holding voltage of the coil can change according to the change amplitude of the contact current, indicating that the control strategy can effectively prevent the unreliable holding of the contactor caused by overload. ② When the coil current drops to a certain threshold, the output voltage of the holding power supply rises, ensuring that the AC contactor can still operate reliably when the coil is powered on for a long time or the coil is heated due to the rise of the ambient temperature. ③ In case of aging of the contactor, change of mechanism characteristics, or unreliable holding of the contactor due to external vibration and other emergencies, the multiple feedback parameter adaptive holding control module will conduct secondary control on the coil based on the induced electromotive force, effectively prevent the separation of moving and static contacts, and ensure the normal operation of the main circuit.
Liu Xiangjun,Yang Cheng,Zhou Yuyuan. Adaptive Holding Control Strategy of AC Contactor Based on Multiple Feedback Parameters[J]. Transactions of China Electrotechnical Society, 2023, 38(2): 554-562.
[1] 李奎, 张国盼, 郑淑梅, 等. 基于实时服役参数的交流接触器电寿命最大化控制策略[J]. 电工技术学报, 2021, 36(9): 1976-1985. Li Kui, Zhang Guopan, Zheng Shumei, et al.A control strategy for maximizing the electrical life of AC contactors based on real-time operating para-meters[J]. Transactions of China Electrotechnical Society, 2021, 36(9): 1976-1985. [2] 游颖敏, 王景芹, 舒亮, 等. 基于音频特征的交流接触器电寿命预测方法[J]. 电工技术学报, 2021, 36(9): 1986-1998. You Yingmin, Wang Jingqin, Shu Liang, et al.The method of electrical life prediction considering the audio characteristics of AC contactor[J]. Transactions of China Electrotechnical Society, 2021, 36(9): 1986-1998. [3] 赵升, 舒亮, 吴自然, 等. 电磁-永磁复合型接触器数值仿真与控制方法[J]. 电工技术学报, 2020, 35(5): 1083-1092. Zhao Sheng, Shu Liang, Wu Ziran, et al.Numerical simulation and control method of electromagnetic-permanent composite contactor[J]. Transactions of China Electrotechnical Society, 2020, 35(5): 1083-1092. [4] 李立志, 史仍辉, 李杰正. 交流接触器磁保吸双线圈电磁驱动器的研究[J]. 电工技术学报, 2014, 29(增刊1): 145-148. Li Lizhi, Shi Renghui, Li Jiezheng.Research on two-coil magnetic latching electromagnetic actuator for AC contactor[J]. Transactions of China Electro-technical Society, 2014, 29(S1): 145-148. [5] 陈德为, 张培铭. 基于人工鱼群算法的智能交流接触器虚拟样机优化设计[J]. 电工技术学报, 2011, 26(2): 101-107. Chen Dewei, Zhang Peiming.Virtual prototype optimal design of intelligent AC contactors based on artificial fish-swarm algorithm[J]. Transactions of China Electrotechnical Society, 2011, 26(2): 101-107. [6] Bai Yongjiang, Yang Xu, Zhang Dan, et al.Con-ducted EMI mitigation schemes in isolated switching-mode power supply without the need of a Y-capacitor[J]. IEEE Transactions on Power Electronics, 2017, 32(4): 2687-2703. [7] 苏晶晶, 许志红. 新型抗晃电的接触器智能控制器[J]. 低压电器, 2011(23): 12-17. Su Jingjing, Xu Zhihong.New intelligent controller for anti-voltage sag[J]. Low Voltage Apparatus, 2011(23): 12-17. [8] 罗海海, 许志红. 组合式开关智能分相控制技术的研究[J]. 电器与能效管理技术, 2016(1): 14-21. Luo Haihai, Xu Zhihong.Research on intelligent individual-phase control technology for combined-switches[J]. Electrical & Energy Management Tech-nology, 2016(1): 14-21. [9] 庄杰榕, 许志红. 基于升压斩波级联方式的接触器控制模块设计[J]. 中国电机工程学报, 2016, 36(15): 4281-4290. Zhuang Jierong, Xu Zhihong.Design of the contactor control module based on the cascade boost-chopper[J]. Proceedings of the CSEE, 2016, 36(15): 4281-4290. [10] 许志红, 汤龙飞. 智能交流接触器一体化仿真及数字控制技术[J]. 中国电机工程学报, 2015, 35(11): 2870-2878. Xu Zhihong, Tang Longfei.Co-simulation and digital control technology of the intelligent AC contactor[J]. Proceedings of the CSEE, 2015, 35(11): 2870-2878. [11] 庄杰榕, 许志红. 电磁接触器多变量反馈吸持控制策略的研究[J]. 中国电机工程学报, 2019, 39(5): 1516-1526. Zhuang Jierong, Xu Zhihong.The multivariate feedback control strategy for electromagnetic conta-ctor holding[J]. Proceedings of the CSEE, 2019, 39(5): 1516-1526. [12] 纽春萍, 陈德桂, 张敬菽, 等. 电动斥力作用下低压断路器分断特性的研究[J]. 电工技术学报, 2005, 20(7): 34-38. Niu Chunping, Chen Degui, Zhang Jingshu, et al.Research on the breaking characteristics of low-voltage circuit breaker with the effect of electrody-namic repulsion force[J]. Transactions of China Electrotechnical Society, 2005, 20(7): 34-38. [13] Zhou Lianke, Man Sida, Wang Zhaobin, et al.On the relationship between contact $a$-spots features and electrodynamic repulsion force for electrical appa-ratus[J]. IEEE Transactions on Components, Packaging and Manufacturing Technology, 2018, 8(11): 1888-1895. [14] 庄杰榕, 许志红. 智能电磁接触器自抗扰电流模型预测控制[J]. 电工技术学报, 2018, 33(23): 5449-5458. Zhuang Jierong, Xu Zhihong.The active disturbance rejection with current model predictive control for intelligent electromagnetic contactor[J]. Transactions of China Electrotechnical Society, 2018, 33(23): 5449-5458. [15] 许志红, 张培铭. 基于神经网络的智能交流接触器分断过程设计模型的建立[J]. 电工电能新技术, 2005, 24(4): 22-25, 29. Xu Zhihong, Zhang Peiming.Neural network based design model for intelligent AC contactor in breaking course[J]. Advanced Technology of Electrical Engin-eering and Energy, 2005, 24(4): 22-25, 29.
2023, Vol. 38 
