电潜泵中压变频调速系统的改进

电潜泵中压变频器输出端产生高次谐波和脉冲电流 ,对电潜泵电动机的绝缘性能和轴承寿命造成不利影响。为此 ,提出 3项改进对策 :①采用谐振软性开关逆变电路 ,使功率开关器件在零电压条件下导通 ;②在变频器逆变输出端设置电抗滤波器抑制高次谐波电流 ;③改变电动机内部结构 ,如加大定子槽宽 ,增加转子导条尺寸 ,变星接法为星 角接法 ,采用绝缘轴承等。实践证明 ,采取改进对策后 ,不仅提高了电潜泵的产量 ,而且变频器滤波后电动机端的过电压明显减小 ,电潜泵和电缆的寿命延长

Improvement of medium-voltage variable frequency speed-regulating system of ESP

Higher harmonic and pulsing current are often produced at the output end of the medium-voltage frequency converter of an electric submersible pump (ESP), and they may be harmful to the insulating property and bearing life of the electric motor of the ESP. Thereby measures for improvement are put forward as follows: (1) adopting zero-voltage switching on/off method to control d v /d t ; (2) connecting AC reactor at the inversion output end of frequency converter to restrain producing higher harmonic current; (3) reconstructing the structure of the electric motor of ESP. Practice shows that, after the above-mentioned improvement, not only the oil production of the ESP well is increased, but also the life of the ESP and cables are extended.