Methods and system for controlling a linear motor for a deep well oil pump

A downhole linear motor pump system comprising:

• a downhole linear electric motor having a stator and a shaft configured to move linearly relative to said stator;
• a downhole pump having an inlet, an outlet, and a piston coupled to said downhole linear motor shaft;
• a motor driver system connected with said downhole linear motor and configured to provide drive commands to said downhole linear motor;
• a surface control computer connected with said motor drive system and configured to control said downhole linear motor;
• a sensor system communicating with said control computer and configured to sense operating parameters of said downhole linear motor;
• said sensor system comprising a downhole position sensor configured to sense position of said motor shaft, a downhole pump inlet pressure sensor, and a current sensor configured to sense motor driver output current;
• and
• said control computer programmed to determine motor output force from said motor driver output current.