Abstract: A wafer manufacturing method, an epitaxial wafer manufacturing method, and a wafer and epitaxial wafer manufactured thereby, are provided. The wafer manufacturing method enables the manufacture of a wafer with a low density of micropipe defects and minimum numbers of particles and scratches. The epitaxial wafer manufacturing method enables the manufacture of an epitaxial wafer that has low densities of defects such as downfall, triangular, and carrot defects, exhibits excellent device characteristics, and improves the yield of devices.

Abstract: A motor drive device is proposed. The motor drive device is configured to drive a motor having a plurality of windings respectively corresponding to a plurality of phases, and includes: a first inverter including a plurality of first switching elements, and connected to a first end of each of the plurality of windings; a second inverter including a plurality of second switching elements, and connected to a second end of each of the plurality of windings; and a controller configured to generate phase voltage commands of the first inverter and phase voltage commands of the second inverter based on preset voltage commands of the motor so that the phase voltage commands of the first inverter and the phase voltage commands of the second inverter are respectively represented as vectors of different angles.

Abstract: An apparatus and method for suppressing torque generation of a three-phase motor, includes a torque determination device that determines a second torque value for suppressing a first torque value due to a zero phase sequence component current of the three-phase motor, a control amount determination device that determines a voltage control amount for generating the determined second torque value, and a controller that is configured to control the three-phase motor according to the determined voltage control amount.

Abstract: A wafer manufacturing method, an epitaxial wafer manufacturing method, and a wafer and epitaxial wafer manufactured thereby, are provided. The wafer manufacturing method enables the manufacture of a wafer with a low density of micropipe defects and minimum numbers of particles and scratches. The epitaxial wafer manufacturing method enables the manufacture of an epitaxial wafer that has low densities of defects such as downfall, triangular, and carrot defects, exhibits excellent device characteristics, and improves the yield of devices.

Abstract: A system for estimating a rotor resistance of an induction motor includes: an equivalent torque curve generation unit to generate an equivalent torque curve based on output torques of the induction motor; a minimum current operation point determination unit to determine a minimum current operation point of the equivalent torque curve; an equivalent current phase variable control unit to variably control a rotor resistance of the induction motor when a stator current command of the minimum current operation point is applied to the induction motor; an output torque detection unit to detect the output torque of the induction motor when the rotor resistance is variably controlled; and a rotor resistance determination unit to determine a maximum torque among the detected output torques and determine an actual rotor resistance of the induction motor based on the rotor resistance when the maximum torque is generated.

Abstract: A motor drive device is proposed. The motor drive device is configured to drive a motor having a plurality of windings respectively corresponding to a plurality of phases, and includes: a first inverter including a plurality of first switching elements, and connected to a first end of each of the plurality of windings; a second inverter including a plurality of second switching elements, and connected to a second end of each of the plurality of windings; and a controller configured to generate phase voltage commands of the first inverter and phase voltage commands of the second inverter based on preset voltage commands of the motor so that the phase voltage commands of the first inverter and the phase voltage commands of the second inverter are respectively represented as vectors of different angles.

Abstract: An apparatus and method for suppressing torque generation of a three-phase motor, includes a torque determination device that determines a second torque value for suppressing a first torque value due to a zero phase sequence component current of the three-phase motor, a control amount determination device that determines a voltage control amount for generating the determined second torque value, and a controller that is configured to control the three-phase motor according to the determined voltage control amount.

Abstract: A battery heating system and method using a motor driving system are provided. A temperature of a battery is increased by injecting an alternating current into the battery so that charging and discharging of the battery is repeated using the motor driving system including an inverter and a motor provided in a vehicle.

Abstract: A battery-heating system and method using a motor-driving system is provided. The battery-heating system includes an inverter having legs respectively including a pair of switching elements connected in series between the ends of a battery and corresponding to a plurality of phases. A motor of the system includes coils each having one end connected to a connection end between a pair of switching elements of the legs, other ends of the plurality of coils being connected together. A controller determines one of the plurality of phases as a reference phase, and alternately controls the on-off states of the switching elements so that the on-off state of the switching element included in the leg corresponding to the reference phase and the switching element included in the other leg are mutually complementary, thereby generating AC current to be injected into the battery.

Abstract: A DC-to-DC converter includes a first capacitor, first to fourth switches connected in series between first and second electrodes of the first capacitor, a second capacitor connected to a connection node of the first switch and the second switch and a connection node of the third switch and the fourth switch, an inductor connected to a connection node of the second switch and the third switch, and a controller that performs PWM control. In a case where a failure occurs in the second capacitor, the DC-to-DC converter performs PWM control such that the first switch and the second switch enter the same state and the third switch and the fourth switch enter the same state on the basis of a result of comparison between a first detection voltage that is a measured output voltage and a target output voltage of the DC-to-DC converter.

Abstract: An embodiment vehicle charging device includes a battery, an inverter electrically connected to the battery, a communicator configured to communicate with a constituent element included in a vehicle, and a controller configured to identify whether a person is present within a predetermined reference distance range from the vehicle based on signals received through the communicator during charging of the battery and to adjust a switching frequency of the inverter such that a voltage supplied to the battery is converted based on the identification result indicating presence or absence of the person within the predetermined reference distance range.

Abstract: A DC-to-DC converter includes a first capacitor, first, second, third, and fourth switches connected in series between first and second electrodes of the first capacitor, a second capacitor connected to a connection node of the first switch and the second switch and a connection node of the third switch and the fourth switch, an inductor connected to a connection node of the second switch and the third switch, and a controller that controls an on/off state of each of the first to fourth switches on the basis of a value obtained by applying a reciprocal of a detection current that is a measured current flowing through the inductor to a difference between a first detection voltage and a first voltage instruction value and a difference between a second detection voltage and a second voltage instruction value.

Abstract: A multi-input charging system and a multi-input charging method using a motor driving system can promptly compulsorily discharge a high charging voltage formed in a neutral point capacitor forming a neutral point voltage in a charging process and formed in a DC capacitor between an inverter and a battery.

Abstract: A battery-heating system and method using a motor-driving system is provided. The battery-heating system includes an inverter having legs respectively including a pair of switching elements connected in series between the ends of a battery and corresponding to a plurality of phases. A motor of the system includes coils each having one end connected to a connection end between a pair of switching elements of the legs, other ends of the plurality of coils being connected together. A controller determines one of the plurality of phases as a reference phase, and alternately controls the on-off states of the switching elements so that the on-off state of the switching element included in the leg corresponding to the reference phase and the switching element included in the other leg are mutually complementary, thereby generating AC current to be injected into the battery.

Abstract: A multi-input charging system and method using a motor driving system can prevent relay fusing or cutting in a motor and damage of a neutral point capacitor provided in a charging power input stage in a process of receiving external charging power through a neutral point of the motor and charging a battery.

Abstract: A battery heating system and method using a motor driving system are provided. A temperature of a battery is increased by injecting an alternating current into the battery so that charging and discharging of the battery is repeated using the motor driving system including an inverter and a motor provided in a vehicle.

Abstract: A flying DC-to-DC converter has a capacitor protection function of preventing a flying capacitor from overheating. The flying DC-to-DC converter estimates the temperature of a capacitor on the basis of a switching duty and an inductor current determined according to a result of comparison between an output voltage and a voltage instruction value, and determines whether to perform de-rating.

Abstract: A flying DC-to-DC converter has a capacitor protection function of preventing a flying capacitor from overheating. The flying DC-to-DC converter estimates the temperature of a capacitor on the basis of a switching duty and an inductor current determined according to a result of comparison between an output voltage and a voltage instruction value, and determines whether to perform de-rating.

Abstract: A DC-to-DC converter includes a first capacitor, first to fourth switches connected in series between first and second electrodes of the first capacitor, a second capacitor connected to a connection node of the first switch and the second switch and a connection node of the third switch and the fourth switch, an inductor connected to a connection node of the second switch and the third switch, and a controller that performs PWM control. In a case where a failure occurs in the second capacitor, the DC-to-DC converter performs PWM control such that the first switch and the second switch enter the same state and the third switch and the fourth switch enter the same state on the basis of a result of comparison between a first detection voltage that is a measured output voltage and a target output voltage of the DC-to-DC converter.

Abstract: A DC-to-DC converter includes a first capacitor, first, second, third, and fourth switches connected in series between first and second electrodes of the first capacitor, a second capacitor connected to a connection node of the first switch and the second switch and a connection node of the third switch and the fourth switch, an inductor connected to a connection node of the second switch and the third switch, and a controller that controls an on/off state of each of the first to fourth switches on the basis of a value obtained by applying a reciprocal of a detection current that is a measured current flowing through the inductor to a difference between a first detection voltage and a first voltage instruction value and a difference between a second detection voltage and a second voltage instruction value.