What are the methods to solve the surge of centrifugal compressor?

The root causes of surge are: low speed and high pressure head; ; Low flow, high pressure head. The treatment in operation is very simple: increase the inlet flow, reduce the outlet pressure head and increase the speed. Note: The flow and lift referred to include all parts. Not just the last exit. As for preventing equipment and instruments from interlocking, special institutions are needed to design and deal with them.