Abstract: A water pumping system, a motor drive, and a method of starting pumping by the motor drive. The method includes powering the electric motor with a motor drive; driving a progressive cavity pump with the electric motor; monitoring a speed difference between an electrical speed and an observed speed of a rotor of the electric motor; and performing a protective action as a function of the speed difference.

Abstract: A water pumping system, a motor drive, and a method of starting pumping by the motor drive. The method includes powering the electric motor with a motor drive; driving a progressive cavity pump with the electric motor; monitoring a speed difference between an electrical speed and an observed speed of a rotor of the electric motor; and performing a protective action as a function of the speed difference.

Abstract: A pumping system and method for operating a pumping system including a motor coupled to a variable speed drive to drive a pump. A torque indicator corresponding to the torque presented to the drive is determined. The torque indicator may be used to detect a fault if it exceeds a baseline torque, or to detect a defective transducer, or to detect a system change by perturbing one parameter and comparing another to a predicted value.

Abstract: This disclosure relates to a power conversion system to power a variable impedance load with a variable power source, the power conversion system comprising a power converter including input terminals adapted to receive variable power from the variable power source and output terminals providing a converted power to the variable impedance load based on the variable power received at the input terminals. The power converter increases the input voltage to an output voltage. The power converter is configured to reflect a source impedance of the variable power source to the variable impedance load.

Abstract: A pumping system and method for operating a pumping system including a motor coupled to a variable speed drive to drive a pump. A torque indicator corresponding to the torque presented to the drive is determined. The torque indicator may be used to detect a fault if it exceeds a baseline torque, or to detect a defective transducer, or to detect a system change by perturbing one parameter and comparing another to a predicted value.

Abstract: This disclosure relates to a power conversion system to power a variable impedance load with a variable power source, the power conversion system comprising a power converter including input terminals adapted to receive variable power from the variable power source and output terminals providing a converted power to the variable impedance load based on the variable power received at the input terminals. The power converter increases the input voltage to an output voltage. The power converter is configured to reflect a source impedance of the variable power source to the variable impedance load.

Abstract: A circuit regulates charging of a rechargeable storage device having a pair of device terminals by a photovoltaic cell having a pair of cell terminals. The circuit has a pair of input terminals for coupling to the cell terminals and a pair of output terminals for coupling to the device terminals. The circuit includes a switch for selectively establishing and breaking an electrical connection between the input terminals and the output terminals and a variable resistor coupled to the device terminals for providing a signal proportional to a terminal voltage across the output terminals. The circuit also includes first and second operational amplifiers responsive to the signal and respective first and second voltage limits, each operational amplifier causing the switch to establish an electrical connection between the input terminals and the output terminals when the signal is equal to a predetermined proportion of the respective voltage limit.