The sewage treatment submersible pump control system using D32 frequency converter has been put into operation for more than three years, and has achieved good economic and social benefits:

• The control device operates reliably, has good environmental adaptability, can resist harsh environments such as oil pollution, dust and damp heat, and has a low failure rate;

• Excellent current limiting characteristics, strong overload capacity, can effectively reduce frequency conversion overload, overcurrent protection, and maximize production continuity;

• According to the needs of the process, make the motor soft start/soft stop, so that the sudden twist and water hammer phenomenon can be solved;

• The economic benefits are remarkable, the power saving effect is more than 20%, and the entire investment increased by the frequency conversion control system can be recovered in more than one year.