Abstract: A pumping system for at least one aquatic application includes a motor coupled to a pump and a controller in communication with the motor. The controller is adapted to determine a first motor speed of the motor, determine a reference power consumption using a reference flow rate and a curve of speed versus power consumption for the reference flow rate, and generate a difference value between the reference power consumption and a present power consumption. The controller drives the motor to reach a steady state condition at a second motor speed based on the difference value.

Abstract: An algorithm for identifying a motor type of a multi-phase (typically 3-phase) motor is described. The algorithm applies a series of active voltage vector pulses to the phases of the motor and measures the current rise-time for each applied voltage vector. The motor type is determined on the basis of the measured current rise-times.

Abstract: A pumping system for at least one aquatic application controlled by a user. The pumping system includes a pump and a motor disposed in a first housing and coupled to the pump. A user interface is associated with a second housing, the second housing defined by a base portion shaped to interact with the first housing and a user interface portion that carries a plurality of control buttons, wherein the second housing is selectively positionable among a plurality of positions relative to the first housing.

Abstract: A method of determining electromagnetic characteristics of an asynchronous motor system is described. A motor system model is presented including a stator resistance, a transient inductance, a magnetizing inductance and a rotor resistance. A DC sequence is used to determine the stator resistance, a voltage pulse is used to determine the transient inductance, a binary injection frequency search algorithm is used to determine the magnetizing inductance, and an AC sine wave at slip frequency with DC offset is used to determine the rotor resistance.

Abstract: A method and apparatus for catching a rotating motor is described. Switches (typically the lower switches) of an inverter of a motor drive circuit are short-circuited for a brief period of time. The pulses generated by this process are analysed to determine the speed and direction of rotation of the motor. The pulses are checked to determine whether they are orthogonal. If they are, the motor velocity determination is deemed to be reliable and then motor is magnetised and normal motor control can be resumed. If not, the motor velocity determination is deemed to be unreliable and a magnetization pulse before the velocity determination step is repeated.

Abstract: The present invention provides systems and methods for reducing harmonics, for example when using an AC to AC converter to drive a load such as a motor drive. In a first embodiment, a plurality of load driving circuits is provided, each drawing current from a 3-phase AC supply and driving an AC load, wherein each of said load driving circuit includes a 3-phase rectifier, with the rectifiers of the load driving circuits being controlled such that the rectification of the AC supply by the load driving circuits is staggered. In a second embodiment, a load driving circuit comprises an electronic inductor configured to control the DC link voltage and/or current such that the current drawn from the AC supply by the load driving circuit has a stepped profile. The first and second embodiments may be combined.

Abstract: A method (19) of cooling a heat generating device (2) where the cooling rate (17, 18) of the heat generating device (2) is determined using the rate of change of the temperature (16) of the heat generating device (2).

Abstract: A method of controlling a motor drive having a normal mode wherein a DC link voltage is charged using an AC (e.g. mains) power supply and an emergency mode wherein the DC link voltage is charged using a DC supply (e.g. from a battery) is described. In the normal mode of operation, if the DC link voltage falls below a threshold indicative of the AC power supply being lost, the emergency mode is entered, typically following an intervening coast mode (during which the motor is not driven). Similarly, in the emergency mode, if the DC link voltage rises above a threshold indicative of the AC power supply being restored, the normal mode is entered, typically following an intervening coast mode.

Abstract: A method of initiating a grid-tied inverter is described, in which in-rush currents and DC overvoltage conditions are reduced or avoided. The method uses a pulse width modulator to drive the inverter under the control of a voltage feedforward signal such that the inverter output is dependent on the measured grid voltage. Then, an AC current feedback controller is enabled and the pulse width modulator is used to drive the inverter under the control of both the voltage feedforward control signal and the feedback control signal.

Abstract: A cover for a motor drive is provided. The cover includes an opening (often at the bottom of the cover) to allow air to pass to an air inlet of the motor drive and an opening (often near the top of the cover) to allow air from an air outlet of the motor drive to exit the cover. A hood provides rain protection for the drive and a separator (such as a baffle) within the enclosure prevents air flowing within the enclosure from the air outlet to the air inlet of the drive. The hood and/or the separator are shaped to direct air from the air outlet away from the enclosure in order to substantially reduce the re-circulation of air from the air outlet to the air inlet of the drive.

Abstract: The invention relates to an arrangement having at least one electric potential-varying device for varying the electric potential of at least one electrical device with respect to earth potential, and a plant room facility. In the operating state, the electric potential-varying device is disposed in the plant room facility.