Lg Electronics Inc.

Korea Electronics Technology Institute

Joonsung Park

Jinhong Kim

Kwangwoon Ahn

Junhyuk Choi

Youngcheol Han

Donghan Kim

Kiwon Noh

Kyeongweon Lee

Byongjo Hyon

Jeehyun Kim

Byunghoon Woo

Yongsu Noh

Dongmyoung Joo

Sunghyun Ki

Wonhyun Jung

Sanghyun Lim

Donghan Kang

Changkyu Kim

Insoung Jung

Bon Gwan Gu

Kyeongbae Park

Byungju Kim

Simoon Jeon

This application relates to a wide band gap (WBG) power semiconductor system. In one aspect, the system includes a controller configured to generate a switching control signal and a gate driver configured to receive the switching control signal and generate a switching drive signal in response to the switching control signal. The system also includes a WBG power semiconductor device coupled to the gate driver, comprising a gate terminal for receiving the switching drive signal, and configured to be switched in response to the switching drive signal. The switching drive signal has one of three signal levels: a first voltage level higher than a zero voltage level, a second voltage level lower than the zero voltage level, and the zero voltage level at an arbitrary instant. As a result, the gate driver drives the WBG power semiconductor device with the three voltage levels.

Wide band gap power semiconductor system and driving method thereof

Provided is a linear compressor including a linear motor having a mover reciprocating with respect to a stator; a piston coupled to the mover to reciprocate; a cylinder into which the piston is slidingly inserted, the cylinder having an inner circumferential surface forming a bearing surface together with an external circumferential surface of the piston, the cylinder forming a compression space together with the piston, and the cylinder having at least one first hole formed through the inner circumferential surface of the cylinder and an outer circumferential surface of the cylinder to guide refrigerant discharged from the compression space to the bearing surface; and a porous member inserted into the outer circumferential surface of the cylinder and configured to cover the first hole, the porous member having multiple micropores smaller than the first hole.

Linear compressor

A linear compressor is provided that may include a casing, a compressor body accommodated in the casing and defining a compression space for a refrigerant, a suction pipe coupled to a first side of the casing to supply the refrigerant to the compression space, a discharge pipe coupled to a second side of the casing to discharge the refrigerant compressed in the compression space outside of the casing, a process pipe coupled to the second side of the casing spaced apart from the discharge pipe to inject a refrigerant for supplement into the casing, and a separator that separates a mixed fluid of a refrigerant and oil injected through the process pipe.

The present disclosure provides a motor drive device and a motor drive system for improving a control stability despite an imbalance in zero crossing points in a sensorless motor of which position of a rotor is estimated by a counter electromotive force. The motor drive device includes: a position detector configured to detect a rotational position of a rotor of a motor by detecting a plurality of zero crossing points of a counter electromotive force induced in the motor; and a controller configured to control the motor by estimating a phase change timing based on a time interval between a current zero crossing point and a previous zero crossing point of a same state as the current zero crossing point among the plurality of zero crossing points detected by the position detector.

Motor drive device and motor drive system

A linear compressor is provided. The linear compressor may include a frame coupled to a cylinder, a gas hole defined in the frame, and a gas pocket that communicates with the gas hole and transfers a refrigerant gas to the cylinder.

Disclosed are an apparatus, system and method for detecting, based on a mathematical model, a fault of a permanent magnet motor driven by a square wave. A fault diagnosis apparatus for the permanent magnet motor includes a current voltage measurement unit, a phase shift time calculation unit, and a control unit.

Apparatus, system and method of fault diagnosis for permanent magnet motor

A linear compressor is provided. The linear compressor may include a cylinder; a frame coupled to an outer side of the cylinder; a cylinder groove defined on an outer circumferential surface of the cylinder; and a sealing member provided in the cylinder groove. The sealing member may be provided between the outer circumferential surface of the cylinder and an inner circumferential surface of the frame.

A linear compressor and a method of manufacturing a linear compressor are provided. The linear compressor may include a shell including a suction inlet, a cylinder having a compression space, in which a refrigerant suctioned in through the suction inlet may be compressed, a piston reciprocated within the cylinder, a first surface treatment disposed on an outer surface of the piston, the first surface treatment having a first hardness value, which is a measured hardness value, and a buffer disposed between the outer surface of the piston and the first surface treatment. The buffer may have a second hardness value, which is a measured hardness value. The first hardness value of the first surface treatment may be greater than the second hardness value of the buffer.

Linear compressor and method of manufacturing a linear compressor

The present disclosure relates to reciprocating compressor. The present invention can prevent friction loss or abrasion between a cylinder and a piston, which is caused when a hydraulic bearing is blocked with a foreign substance, by preventing the foreign substance mixed in refrigerant gas from flowing into the hydraulic bearing, and can improve compressor performance by preventing a specific volume in a compression space from increasing when high-temperature refrigerant gas discharged in the compression space is cooled, such that vibration noise of the compressor can be reduced since a gas guiding part offsets vibration and the noise generated when a refrigerant is discharged in the compression space. Furthermore, the number of vibrations of a mover is increased and a driving operation for removing foreign substances is carried out to increase the number of vibrations of a cylinder such that any foreign substance stuck in a gas hole can be cleaned, thereby increasing performance and reliability of the compressor.

Reciprocating compressor and method for driving same

An inverter apparatus having a power supply circuit includes a converter circuit for rectifying AC power into DC power, a smoothening circuit for smoothening the rectified DC power, an inverter circuit for converting the smoothened DC into AC at a variable frequency through a plurality of switches to control a load, and a current detection circuit for detecting overcurrent from the smoothened DC supplied from the inverter circuit, wherein the inverter circuit applies bootstrap power for driving the switches to the current detection circuit to use the bootstrap power as power of the current detection circuit. When bootstrap power for driving switch gates is used, it is possible to use the bootstrap power as the power of the current detection circuit by adding the auxiliary circuit composed of a small number of passive elements.

Growing community of inventors

Seoul, South Korea

Joonsung Park