Class / Patent application number | Description | Number of patent applications / Date published |
318805000 | Responsive to motor voltage | 8 |
20080224650 | FEED MOTOR LOCK DETECTION DEVICE - A feed motor lock detection device detects a back-electromotive voltage in a feed motor M and checks whether the feed motor M is in a driven state or in a non-driven state based on the level of the back-electromotive voltage. | 09-18-2008 |
20090001925 | Power Conversion Circuit - A desired current is caused to flow through a coil by controlling switching of switching elements by a PWM controller. For a voltage sensor, a value of Vo−ΔV, which is a difference between a midpoint voltage Vo of the switching elements and a predetermined threshold voltage ΔV, and a value of Vo−(Vc−ΔV), which is a difference between the midpoint voltage Vo and a value obtained by subtracting the threshold voltage ΔV from a voltage Vc of an upper line, are determined. Then, the determined results obtained from the voltage sensor are input to the PWM controller through flip-flops and a dead time compensator to compensate for dead time, such as, for example, for a command for PWM control signal generation. | 01-01-2009 |
20110248663 | CONTROL SYSTEM FOR AC MOTOR - A control system for an AC motor determines a slope Ktl of a tangent TL at an operating point Pa corresponding to the current motor operating state and voltage phase (θ | 10-13-2011 |
20120212172 | MODULAR LINE-TO-GROUND FAULT IDENTIFICATION - The present invention relates generally to systems and methods for detecting ground faults (i.e., line-to-ground faults) in electrical power conversion systems. In particular, the embodiments described herein include a common mode voltage booster module configured to calculate a common mode voltage boost factor and a common mode voltage boost function based on a plurality of voltage commands for the system. The common mode voltage boost factor and/or the common mode voltage boost function may be applied to the voltage commands to generate boosted voltage commands which, when applied to an inverter or converter, source current indicative of ground faults in the system. More specifically, the common mode voltage boost factor may be multiplied by a common mode voltage calculated by a common mode voltage calculator and summed with the voltage commands. In addition, the common mode voltage boost function may be summed with the voltage commands after the voltage commands have been summed with the common mode voltage boost factor. | 08-23-2012 |
20120223668 | Control Method and System with Feedback Indicative of Load Flux - Systems, methods, and devices are disclosed, including an induction-motor controller having a phase path; a solid-state switch interposed on the phase path; and a controller coupled to the solid-state switch. In certain embodiments, the controller is configured to switch the solid-state switch so that the solid-state switch is conductive during a conduction angle of a cycle of an incoming AC power waveform conveyed by the phase path, calculate the conduction angle based on a generally sinusoidal reference value that has a frequency lower than a frequency of the incoming AC power waveform, and adjust the generally sinusoidal reference value based on a value indicative of flux in a load coupled to the phase path. | 09-06-2012 |
20130257343 | CONTROL METHOD FOR INDUCTION MOTOR - In order to cause the residual magnetic flux in an induction motor to decay in a short time without an excessive current flow, an induction motor control apparatus continues an operation in which an inverter apparatus is caused to output a zero voltage to the induction motor for a predetermined time before deactivating an operation of the inverter apparatus. | 10-03-2013 |
20140368152 | Method of Controlling a Pump and Motor - Embodiments of the invention provide a variable frequency drive system and a method of detecting a ground in a system having a pump driven by a motor. The drive system and method can provide one or more of the following: a sleep mode, pipe break detection, a line fill mode, an automatic start mode, dry run protection, an electromagnetic interference filter compatible with a ground fault circuit interrupter, two-wire and three-wire and three-phase motor compatibility, a simple start-up process, automatic password protection, a pump out mode, digital input/output terminals, and removable input and output power terminal blocks. | 12-18-2014 |
20150381094 | INDEPENDENT PATHWAYS FOR DETECTING FAULT CONDITION IN ELECTRIC MOTOR - An electric motor system having substantially independent hardware-based and software-based pathways for detecting and initiating responses to fault conditions, such as over-current conditions, in an electric motor which is powered by a power inverter which is controlled by a power module and a microprocessor. Each pathway involves comparing a voltage, which is representative of an electric current flowing to the motor, to a predetermined maximum voltage, and if the former exceeds the latter using hardware or software to initiate shutting off the motor, such as by shutting off the power inverter. When one pathway detects a fault condition it may notify the other pathway, and the notified pathway may also initiate shutting off the motor. | 12-31-2015 |