PCP and ESP control program for low voltage ACS880 industrial drives

In the core of the control program is the backspin control. When PCP or ESP is stopped, and fluid flows back to the well, this function controls the reverse rotation of the rotor.

In the case of PCP pump the rod connecting the motor to the pump has rotational tension while it is operating, when the motor is stopped this tension will unwind rapidly. This rapid release of energy must be controlled to avoid damage to the rod.

With ESP there is no risk of damaging the equipment, but the reverse rotation must be identified to prevent starting of the motor.

The PCP and ESP control modes utilize the direct torque control (DTC) function, which means that no additional devices are needed for torque control purposes. In high and low torque situations drive can be set to automatically reduce the speed of the pump. For underload situations, control program can have a user-defined speed-torque curve which acts as a reference for shutting down the system. These functions protect the pump system and reduce energy consumption.

Thermal protection function supervises the pump temperature based on a temperature signal from an external sensor and starts the shutdown procedure after the set level is reached.

Pressure protection function provides pump protection from high pressure or high discharge pressure. When pump is shut down due to high pressure, it can be set to restart automatically after pressure level is back within operation limits. This eliminates the need of manual restart, thus saving time and raising your production rates.

Fluid level control function uses input from built in PI controller to keep optimal fluid level in well. Speed of the pump is adjusted according the value of actual fluid level, based on data from pressure or fluid level sensor. With this concept you can keep production rate at the optimum level during the whole process time. The control program also has a sleep-function which will shut down the pump if fluid level goes below set level and starts it again after the fluid level is within set limits. With an unstable oil well the sleep-function can generate significant energy savings.

In addition to linear and s-shape acceleration ramps, you can set the pump to accelerate in two stages. After first linear acceleration, pump waits at set speed before ramping up to final reference speed. For example, the first part of the ramp might be set to slower acceleration in order to protect the equipment. The control program has also a jogging function which can be used for maintenance and position purposes.

The control program has ability to supervise and control variety of pump conditions based on signals received from instrumentation in the artificial lift system.