191 results about "Adjustable-speed drive" patented technology

Zero current transition (ZCT) topologies are presented for three-phase inverters and rectifiers. Such devices are used for example in AC adjustable speed drives for so-called zero-emission vehicles (i.e., electric and hybrid combustion / electric automobiles). Compared to existing three-phase ZCT techniques, the number of auxiliary switches is reduced from six to three, while not altering the necessary device rating. Correspondingly, the number of gate-drivers for the auxiliary switches is also reduced to three. Meanwhile, the merits of the existing three-phase ZCT techniques are still retained, i.e., all the main switches and the auxiliary switches are turned on and turned off under zero-current conditions, and the independent commutation for each main switch is achieved. The desired soft-switching features are achieved. Therefore, this invention will contribute to more cost-effective, reliable, and efficient high-performance three-phase inverters and rectifiers.

A cable and termination system for use with adjustable speed drives, including flexible tray cables and metal-clad cables, and terminations coupled therewith. The cables generally include three phase conductors, three ground conductors and fillers, and are wrapped with copper tape and other elements. The terminations coupled with the cables include a plurality of connectors and flexible, tinned-copper braids which act as the shield termination for the copper tape. More detailed and other embodiments of the present invention are disclosed in the specification hereof.

An electric motor with an adjustable speed drive includes a bearing current reduction assembly including a charge concentrator providing a higher electric field concentration through a clearance between an inner bearing cap and a rotor shaft than occurs within a bearing. Accordingly, damaging rotor to ground currents through a bearing are reduced or eliminated. The charge concentrator is disposed on either the rotor shaft or the inner bearing cap, or both.

The present invention relates to a protective circuit to provide over voltage protection for an ASD. The protective circuit provides the benefits of fewer components with lower power ratings than existing protective circuits. The protective circuit may be incorporated directly in the ASD for continuous protection or mounted externally and connected to the ASD under operating conditions that require the circuit. This flexibility for mounting the protective circuit allows the capacitor of the protective circuit to be sized either in relation to capacitive elements on the DC bus within the ASD or according to external capacitance observed at the output of the ASD. In addition, the circuit is only operative during an overvoltage condition allowing for power ratings lower than would be required for continuous operation.

Apparatus and method for controlling power in an auxiliary power system of a thermal power plant having a generator and one or more auxiliary buses. The apparatus includes adjustable speed drives and capacitance sources for connection to the one or more auxiliary buses and sensors for measuring voltage and reactive power on the one or more auxiliary buses. A controller is operable to control the adjustable speed drives and the capacitance sources to control the power factor of the auxiliary power system, while providing steady state voltage regulation and dynamic voltage support.

A strapping machine is provided to feed a strap around a load, position, tension and seal the strap around the load. The strapping machine includes a surface to support the load in the strapping machine; a strap chute to carry a strap around the load and release the strap from the strap chute; a motor assembly to convey the strap around the strap chute, retract the strap material around the load, and tension the strap around the load; and an adjustable speed drive capable of receiving a first reference signal and a second reference signal, and configured to actuate the motor assembly to apply a first amount of torque to the strap when receiving the first reference signal and to apply a second amount of torque to the strap when receiving the second reference signal. The strapping machine also includes a controller configured to operate the adjustable speed drive in a first mode while conveying the strap around the strap chute and retracting the strap material around the load, and a second mode while tensioning the strap around the load. In the first mode, the adjustable speed drive actuate the motor assembly to apply the first amount of torque to the strap, and in the second mode, the adjustable speed drive actuates the motor assembly to apply the second amount of torque to the strap.

A filter for mitigating harmonics in an electrical distribution system. In one embodiment the filter has one winding that is connected to the power distribution system which may be a three phase system and capacitors are connected to other end of the winding in either a delta or y-connection. There is one tapping on the winding for connection to a load which may an adjustable speed drive. In another embodiment the filter has two or more separate reactors. In either embodiment a switch may be in series with the capacitors and capacitors may be connected in parallel with the series combination of switch and capacitors.

A system and method for detecting input phase loss in an adjustable speed drive (ASD) includes an input unit to detect operating data from the ASD. The operating data includes a DC link current of the ASD. The system also includes a state observer that is adapted to receive the operating data from the input unit and extract a DC link capacitor current of the ASD using the DC link current. The system also includes a controller programmed to compare the extracted DC link capacitor current to a predetermined fault range and generate a fault indication of an input phase loss if the extracted DC link capacitor current is within the predefined fault range. The controller is also programmed to calculate an estimated lifespan of the DC link capacitor based on the extracted DC link capacitor current.

In an electrical distribution system for supplying power from an AC source to an adjustable-speed drive connected in a single-phase manner, a device for substantially eliminating harmonic currents in the supply lines of said system. The device includes a completely-passive parallel resonant circuit having three passive electrical branches connected in parallel and also having an almost infinite impendence at a third harmonic frequency of a fundamental frequency of said AC source to prevent the formation of only said third harmonic frequency so that there is no third harmonic current to remove or dissipate as heat. The three passive electrical branches comprise a first branch consisting of a capacitor, a second branch consisting of a reactor, and a third branch consisting of a resistor. The parallel resonant circuit is electrically connected to at least one supply line.

A vibratory separator including a frame, a basket disposed on the frame, and a motor configured to impart a vibratory motion to the basket. Additionally, the vibratory separator includes an adjustable speed drive operatively coupled to the motor to control a vibratory motion imparted to the basket. Also, a method of processing drilling waste including generating a first vibratory motion on a vibratory separator using at least one motor, and adjusting the first vibratory motion using an adjustable speed drive to generate a second vibratory motion.

A filter for mitigating harmonics in an electrical distribution system. In one embodiment the filter has one winding that is connected to the power distribution system which may be a three phase system and capacitors are connected to other end of the winding in either a delta or y-connection. There is one tapping on the winding for connection to a load which may an adjustable speed drive. In another embodiment the filter has two or more separate reactors. In either embodiment a switch may be in series with the capacitors and capacitors may be connected in parallel with the series combination of switch and capacitors.

A vibratory separator including a frame, a basket disposed on the frame, and a motor configured to impart a vibratory motion to the basket. Additionally, the vibratory separator includes an adjustable speed drive operatively coupled to the motor to control a vibratory motion imparted to the basket. Also, a method of processing drilling waste including generating a first vibratory motion on a vibratory separator using at least one motor, and adjusting the first vibratory motion using an adjustable speed drive to generate a second vibratory motion.

The Brushless Multiphase Self-Commutation Controller or BMSCC is an adjustable speed drive for reliable, contact-less and stable self-commutation control of electric apparatus, including electric motors and generators. BMSCC transforms multiphase electrical excitation from one frequency to variable frequency that is automatically synchronized to the movement of the electric apparatus without traditional estimation methods of commutation and frequency synthesis using derivatives of electronic, electro-mechanical, and field-oriented-control. Instead, BMSCC comprises an analog electromagnetic computer with synchronous modulation techniques to first establish magnetic energy and then dynamically share packets of magnetic energy between phase windings of a multiphase, position dependent flux, high frequency transformer by direct AC-to-AC conversion without an intermediate DC conversion stage.