Abstract: Apparatus and methods for controlling electric motors are disclosed. In addition, such apparatus and methods for starting and controlling electric motors and controlling electric motors switching from a PWM control to six step method of control. Methods and apparatus are further included to provide for robust control of an electric motor operating in a six-step running mode.

Abstract: Embodiments are disclosed for the control of downhole pumping systems that can perform a controlled draining operation of the downhole pumping system in the event of an interruption of a drive. Such embodiments include a zero power factor control, a motor braking, and a pumping down operation. The apparatus and the methods disclosed can include an independent piece of equipment interlocked with a variable speed drive, and installed at the primary or secondary of the step-up transformer where used. However, integration within other pieces of equipment, in particular the variable speed drive, and its control by the latter is also contemplated. Also disclosed is a transformer having a tap changer that includes a plurality of taps and contacts including shorting contacts, open contacts and auxiliary contacts.

Abstract: Apparatus and methods for controlling electric motors are disclosed. In addition, such apparatus and methods for starting and controlling electric motors and controlling electric motors switching from a PWM control to six step method of control. Methods and apparatus are further included to provide for robust control of an electric motor operating in a six-step running mode.

Abstract: SOGI based apparatus and methods for providing balanced three phase output signals free of harmonics, DC components and imbalance present in the input signals, are disclosed. In addition, such apparatus and methods for providing corresponding output signals which are drift-free integrals of the input signals and which signals may enable the control of a power electronics inverter for improved and robust grid power injection and for motor control are disclosed.

Abstract: An apparatus and method for controlling a downhole pumping system is disclosed. The apparatus is capable of detecting motor operating conditions and pump operating conditions thereby and includes control systems for utilizing the motor operating conditions to control the operation of the downhole pumping system.

Abstract: An apparatus and method is disclosed to monitor the operating condition of a rotational electromechanical system and to further sense and diagnose an abnormal condition of such systems in real time. The apparatus and method includes an improved technique of monitoring such systems, detecting problems, diagnosing causes and acting on the problems to reduce failures and increase production.

Abstract: Embodiments are disclosed for the control of downhole pumping systems that can perform a controlled draining operation of the downhole pumping system in the event of an interruption of a drive. Such embodiments include a zero power factor control, a motor braking, and a pumping down operation. The apparatus and the methods disclosed can include an independent piece of equipment interlocked with a variable speed drive, and installed at the primary or secondary of the step-up transformer where used. However, integration within other pieces of equipment, in particular the variable speed drive, and its control by the latter is also contemplated. Also disclosed is a transformer having a tap changer that includes a plurality of taps and contacts including shorting contacts, open contacts and auxiliary contacts.

Abstract: An apparatus and method for controlling a downhole pumping system is disclosed. The apparatus is capable of detecting motor operating conditions and pump operating conditions thereby and includes control systems for utilizing the motor operating conditions to control the operation of the downhole pumping system.

Abstract: SOGI based apparatus and methods for providing balanced three phase output signals free of harmonics, DC components and imbalance present in the input signals, are disclosed. In addition, such apparatus and methods for providing corresponding output signals which are drift-free integrals of the input signals and which signals may enable the control of a power electronics inverter for improved and robust grid power injection and for motor control are disclosed.