Mixed Mode Control of Constant Power and Constant Current for Resistance Spot Welder using Dynamic Resistance Characteristics

동저항 특성을 이용한 저항 스폿 용접기의 정전력과 정전류의 혼합모드 제어

Kang, Sung-Kwan;Jung, Jae-Hun;Nho, Eui-Cheol

  • Received : 2015.10.13
  • Accepted : 2015.10.30
  • Published : 2015.11.01


A new mixed mode control of constant power and constant current for resistance spot welding inverter is proposed to improve the weld quality. The conventional control scheme adopts constant current or constant power control mode, however, it is not easy to guarantee the high weld quality because of the nonlinear resistance characteristics of the welding point. The proposed method utilizes the nonlinear characteristics by measuring the dynamic resistance in real time. Therefore, it is possible for the welder to be controlled adaptively depending on the welding state. Experimental results show that the proposed control scheme improves the weld quality by 6.8 times compared with the conventional constant current mode control.


Dynamic resistance characteristics;Weld quality;Constant current and power control


  1. S. M. Cho, "Principle of resistance welding and analysis of monitoring results, "Journal of the Korean Welding & Joining Society, Vol. 15, No. 2, pp. 7-11, Apr. 1997.
  2. Hyungsuck Cho, "Welding quality supervision and control resistance welding processes," Journal of the Korean Welding & Joining Society, Vol. 18, No. 4, pp. 2-7, Aug. 2000.
  3. S.A. Gedeon, C.D. Sorensen, K.T. Ulrish, and T.W. Eagar, "Measurement of dynamic electrical and mechanical properties of resistance spot welds," Weld journal, pp. 185-378, Dec. 1987.
  4. D.W. Dickinson, J.E. Franklin and A. Stantya, "Characterization of spot welding behavior by dynamic electrical parameter monitoring," Welding research supplement, pp. 170-176, Jun. 1980.
  5. J.M. Kim, L.H. Kim, B.G. Min, C.Y. Won, G.S. Kim, and S.W. Choi, "Variable Power Control of Inverter Spot Welding Machine using Evolution Algorithm," The Transactions of The Korean Institute of Power Electronics, Vol. 7, No. 4, pp. 384-394, Aug. 2002.
  6. Yongjoon Cho. Sehun Rhee, Hyun Shin, and Kyungmin Bae, "Charateriztion primary dynamic resistance in spot welding," Journal of the Korean welding & joining society, Vol. 17, No. 2, pp. 159-164, Apr. 1999.
  7. J.M. Kim, Y.C. Kim, C.Y. Won, G.S. Kim, "A study on spot welder of PI controller using evolution strategy," Proceedings of the KIEE EMECS Annual Autumn conference 1997, pp. 531-533, 1997.
  8. M.K. Park and J.W. Lee, "Fuzzy-PID gain scheduling algorithm of resistive welder for electronic parts," 2004 conference on information and control systems, pp. 114-116, 2004.