Abstract: Disclosed is a device for controlling an inverter. The device achieves a minimum switching loss in a discontinuous modulation duration regardless of a power factor. The device includes: a command voltage transform unit configured for transforming each of 3 phases command voltages into each of pole command voltages using the DC stage voltage, a pulse width modulation index, a discontinuous modulation angle corresponding to a discontinuous modulation duration, and each phase difference between each of the 3 phase command voltages and each of 3 phases output currents of the inverting module; and a controller configured for generating a control signal based on a comparison between each pole command voltage and a triangular carrier wave, wherein the control signal controls upper and lower switching elements of each phase leg.

Abstract: Disclosed is a device for controlling an inverter. The device achieves a minimum switching loss in a discontinuous modulation duration regardless of a power factor. The device includes: a command voltage transform unit configured for transforming each of 3 phases command voltages into each of pole command voltages using the DC stage voltage, a pulse width modulation index, a discontinuous modulation angle corresponding to a discontinuous modulation duration, and each phase difference between each of the 3 phase command voltages and each of 3 phases output currents of the inverting module; and a controller configured for generating a control signal based on a comparison between each pole command voltage and a triangular carrier wave, wherein the control signal controls upper and lower switching elements of each phase leg.

Abstract: The present invention provides a battery pack including a base plate including one surface on which two or more battery module assemblies respectively having a plurality of battery cells arranged therein are mounted in a separated state from each other with a predetermined interval therebetween; a cover member battery coupled at one surface of the base plate in a state that the module assemblies are incorporated therein; and a reinforcement supporting member positioned at a separation part between the battery module assemblies while supporting a mounting state of the cover member for the base plate.

Abstract: A surface inspection apparatus includes a camera that captures an image of an object to be inspected, a half mirror disposed above the camera on a first optical axis, and a light source disposed adjacent to the half mirror on a second optical axis that intersects the first optical axis. The light source radiates light, and the light is directed toward the object to be inspected by the half mirror. The surface inspection apparatus further includes a reflector disposed above the half mirror on the first optical axis. The reflector includes a reflective concave surface that faces toward the object to be inspected.

Abstract: An inverter control device is disclosed. The device is configured: for determining a fundamental-wave magnitude of a phase-voltage corresponding to a modified voltage; for performing a proportional-integral (PI) operation of an error between the fundamental-wave magnitude of the phase-voltage and a magnitude of a reference voltage, and for outputting a compensation voltage; configured for adding the compensation voltage to the reference voltage to obtain an output; and for over-modulating the output and for outputting the over-modulated output as the modified voltage.

Abstract: An apparatus for controlling an inverter is disclosed. The apparatus for controlling the inverter contained in an inverter system configured to drive a motor determines a slip frequency to be used for compensation of a frequency of a first reference voltage, not only using a first reference voltage (including an amplitude and frequency) of the first reference voltage applied to the inverter, but also using an output current of the motor or a rotor speed of the motor. The apparatus determines not only a frequency of a second reference voltage obtained by compensation of the slip frequency, but also an amplitude of the second reference voltage corresponding to the frequency of the second reference voltage.

Abstract: The present invention provides a battery pack mounted to a battery pack mounting part of a device for supplying power, including: a base plate including one surface on which two or more battery module assemblies respectively having a plurality of battery cells arranged therein are mounted in a separated state from each other with a predetermined interval therebetween; a cover member mounted on one surface of the base plate while enclosing the battery module assemblies; and a reinforcement supporting member positioned at a separation part between the battery module assemblies while supporting the mounting state of the cover member for the base plate, wherein the battery pack is mounted in a state in which an external circumferential surface of the cover member faces a battery pack mounting part of a device.

Abstract: An apparatus for controlling an inverter is disclosed. The apparatus for controlling the inverter contained in an inverter system configured to drive a motor determines a slip frequency to be used for compensation of a frequency of a first reference voltage, not only using a first reference voltage (including an amplitude and frequency) of the first reference voltage applied to the inverter, but also using an output current of the motor or a rotor speed of the motor. The apparatus determines not only a frequency of a second reference voltage obtained by compensation of the slip frequency, but also an amplitude of the second reference voltage corresponding to the frequency of the second reference voltage.

Abstract: Disclosed is a sensorless control system for a permanent magnet synchronous machine. The sensorless control system includes a counter electromotive force estimation unit configured to estimate a counter electromotive force using a phase voltage reference applied to an inverter and a phase current applied from the inverter to the permanent magnet synchronous machine, and a speed estimation unit configured to estimate an angular velocity and an electrical angle of a rotor of the permanent magnet synchronous machine, and the counter electromotive force estimation unit according to one embodiment of the present disclosure may maintain robust performance at a low speed by modifying some portion of a conventional Luenberger observer.

Abstract: Provided is a method of controlling a three phase equivalent voltage in a multilevel inverter including sensing a state of each of power cells of the multilevel inverter to determine whether or not failure occurs at each of the power cells, bypassing power cells which are determined as being failed to connect power cells operating normally to each other in series per each phase, calculating an offset voltage value using a phase voltage reference per each phase and a sum of each of direct current (DC) link voltages of the power cells which operate normally and configure each of the phases, and calculating a pole voltage reference per each phase for maintaining an equivalence of a three phase line-to-line output voltage using the phase voltage reference per each phase and the calculated offset voltage.

Abstract: In one embodiment, an offset voltage generator includes a first limiter configured to compare a first phase-voltage signal with a maximum limit value and a minimum limit value to output a first limit-voltage signal; a second limiter configured to compare a second phase-voltage signal with the maximum limit value and the minimum limit value to output a second limit-voltage signal; a third limiter configured to compare a third phase-voltage signal with the maximum limit value and the minimum limit value to output a third limit-voltage signal; and a summer configured to add a difference between the first phase-voltage signal and the first limit-voltage signal, a difference between the second phase-voltage signal and the second limit-voltage signal, and a difference between the third phase-voltage signal and the third limit-voltage signal, to output an offset voltage.

Abstract: In an embodiment, an offset voltage generator includes a first limiter configured to compare a first phase-voltage signal with a maximum limit value and a minimum limit value to output a first limit-voltage signal; a second limiter configured to compare a second phase-voltage signal with the maximum limit value and the minimum limit value to output a second limit-voltage signal; a third limiter configured to compare a third phase-voltage signal with the maximum limit value and the minimum limit value to output a third limit-voltage signal; and a summer configured to add a difference between the first phase-voltage signal and the first limit-voltage signal, a difference between the second phase-voltage signal and the second limit-voltage signal, and a difference between the third phase-voltage signal and the third limit-voltage signal, to output an offset voltage.

Abstract: In some embodiments, a system of controlling an induction electric motor, includes a command voltage output unit for generating a command voltage for operating an inverter according to a command speed and outputting the generated command voltage to the inverter; a control unit for controlling the command voltage output unit such that the command voltage output to the inverter is compared with an operation limiting voltage and the command voltage is corrected to fall within the operation limiting voltage; and the inverter for controlling the induction electric motor depending on the corrected command voltage. Thus, it is possible to precisely control the induction electric motor even in a high speed operation region by regulating the magnitude of the command voltage applied to the induction electric motor by means of dynamic modulation strategies without the magnetic flux controller.

Abstract: Disclosed embodiments relate to apparatuses, methods, and systems for restarting an induction machine. In some embodiments, a method includes estimating a position of a rotor and a speed thereof in a position and speed estimation Operation, resetting a speed reference to correspond to the speed of the rotor in a speed reference resetting Operation, generating a control voltage corresponding to the speed reference to regulate a voltage magnitude using the control voltage in a voltage magnitude regulation Operation, and re-accelerating the induction machine up to a target speed after the regulation of the voltage magnitude in a re-acceleration Operation.

Abstract: Provided is a method of controlling a three phase equivalent voltage in a multilevel inverter including sensing a state of each of power cells of the multilevel inverter to determine whether or not failure occurs at each of the power cells, bypassing power cells which are determined as being failed to connect power cells operating normally to each other in series per each phase, calculating an offset voltage value using a phase voltage reference per each phase and a sum of each of direct current (DC) link voltages of the power cells which operate normally and configure each of the phases, and calculating a pole voltage reference per each phase for maintaining an equivalence of a three phase line-to-line output voltage using the phase voltage reference per each phase and the calculated offset voltage.

Abstract: The present invention relates to a novel epoxy compound, a method for preparing same, a composition and cured product comprising same, and use thereof, wherein the compound shows excellent heat-resistant properties—specifically, a low thermal expansion property and a high glass transition temperature (including Tg-less which does not show a glass transition temperature), a flame retardant property and processability—specifically, a viscosity-control property, does not require a separate silane coupling agent, and has improved brittleness in a composite. According to one aspect of the present invention, provided are: an epoxy compound having at least one non-reactive silyl group, alkenyl group or combination thereof together with at least two epoxy groups and at least one alkoxysilyl group; a method for preparing the epoxy compound through alkoxysilylation and alkylsilylation; an epoxy composition comprising same; and a cured product.

Abstract: Disclosed embodiments relate to apparatuses, methods, and systems for restarting an induction machine. In some embodiments, a method includes estimating a position of a rotor and a speed thereof in a position and speed estimation Operation, resetting a speed reference to correspond to the speed of the rotor in a speed reference resetting Operation, generating a control voltage corresponding to the speed reference to regulate a voltage magnitude using the control voltage in a voltage magnitude regulation Operation, and re-accelerating the induction machine up to a target speed after the regulation of the voltage magnitude in a re-acceleration Operation.

Abstract: In some embodiments, a system of controlling an induction electric motor, includes a command voltage output unit for generating a command voltage for operating an inverter according to a command speed and outputting the generated command voltage to the inverter; a control unit for controlling the command voltage output unit such that the command voltage output to the inverter is compared with an operation limiting voltage and the command voltage is corrected to fall within the operation limiting voltage; and the inverter for controlling the induction electric motor depending on the corrected command voltage. Thus, it is possible to precisely control the induction electric motor even in a high speed operation region by regulating the magnitude of the command voltage applied to the induction electric motor by means of dynamic modulation strategies without the magnetic flux controller.

Abstract: In an embodiment, an offset voltage generator includes a first limiter configured to compare a first phase-voltage signal with a maximum limit value and a minimum limit value to output a first limit-voltage signal; a second limiter configured to compare a second phase-voltage signal with the maximum limit value and the minimum limit value to output a second limit-voltage signal; a third limiter configured to compare a third phase-voltage signal with the maximum limit value and the minimum limit value to output a third limit-voltage signal; and a summer configured to add a difference between the first phase-voltage signal and the first limit-voltage signal, a difference between the second phase-voltage signal and the second limit-voltage signal, and a difference between the third phase-voltage signal and the third limit-voltage signal, to output an offset voltage.

Abstract: In one embodiment, an offset voltage generator includes a first limiter configured to compare a first phase-voltage signal with a maximum limit value and a minimum limit value to output a first limit-voltage signal; a second limiter configured to compare a second phase-voltage signal with the maximum limit value and the minimum limit value to output a second limit-voltage signal; a third limiter configured to compare a third phase-voltage signal with the maximum limit value and the minimum limit value to output a third limit-voltage signal; and a summer configured to add a difference between the first phase-voltage signal and the first limit-voltage signal, a difference between the second phase-voltage signal and the second limit-voltage signal, and a difference between the third phase-voltage signal and the third limit-voltage signal, to output an offset voltage.