Abstract:
PURPOSE: An inverter for generating a three-level voltage is provided to simplify a circuit configuration by reducing the number of diodes and switching devices using a bidirectional switch device. CONSTITUTION: A division unit(10) divides input DC power into three voltage levels and is comprised of two same capacitors. A switching device(20) is connected to each node of the division unit with three voltage levels. A bidirectional switching device(30) is connected between an AC voltage output terminal(40) and a middle voltage level node among three voltage levels.
Abstract:
PURPOSE: A multi-level inverter is provided to easily use a high voltage of input direct current power by dividing input direct current power to be varied to a three-phase alternate current. CONSTITUTION: A dividing part(110) divides the voltage level of input direct current based on a pre-set rate. A switching part(120) includes a plurality of switching groups which generates power by switching the divided power from the dividing part and generating power with different phases. A combining part(130) combines power with identical phases from the switched power. A controlling part(140) controls the switching operation of the switching part based on pulse width modulation carrier signal and reference signal which is set by phases.
Abstract:
본 발명은 고전압을 사용할 수 있도록 입력 직류 전원을 분할하여 3상 교류 전원으로 변환하는 다중 레벨 인버터에 관한 것으로, 입력 직류 전원의 전압 레벨을 사전에 설정된 비율에 따라 분할하는 분할부와, 상기 분할부로부터의 분할된 전원을 각각 스위칭하여 서로 다른 복수의 위상을 갖는 전원을 생성하는 복수의 스위치 그룹을 갖는 스위칭부와, 상기 스위칭부의 복수의 스위치 그룹에 의해 각각 스위칭된 전원 중 동일한 위상의 전원끼리 결합하는 결합부를 포함하는 것을 특징으로 하는 다중 레벨 인버터를 제공하는 것이다. 인버터(Inverter), 다중 레벨(Multi Level), 3상(Three Phase)
Abstract:
PURPOSE: A process for manufacturing a negative electrode material for a lithium secondary battery is provided to manufacture various phosphate-based negative electrode materials without thermal process of high temperature and to reduce the time required for whole process. CONSTITUTION: A process for manufacturing a negative electrode material for a lithium secondary battery includes the steps of: mixing transition metal compounds dissolved in distilled water with poly acid phosphate-based compounds to prepare a mixed solution; stirring the mixed solution to prepare a precipitate by a co-precipitation method; drying the precipitate to a temperature of 50-80 °C; and heat-treating the dried material at a temperature of 300-500 °C.
Abstract:
The present invention relates to a power factor correction circuit of a server power supply. The power factor correction circuit according to the present invention comprises a converter unit configured to receive an AC voltage, convert the AC voltage into a DC voltage, and outputs the same; a DCM detection unit configured to determine whether a system operates in a discontinuous conduction mode (DCM) based on a detected current (iL_sen) on a current flowing in an inductor and a reference current (iref); a DCM current control unit configured to control an inductor current during the DCM operation of the system according to a result of the determination of the DCM detection unit; and a continuous conduction mode (CCM) current control unit configured to the inductor current during a CCM operation of the system according to the result of the determination of the DCM detection unit. According to the present invention, by using the detected current on the current flowing in the inductor and the reference current, it is possible to determine whether the system operates in the DCM or CCM, and perform control corresponding to an operation type of the system. Thus, it is also possible to estimate a correct average current even during the DCM operation and to improve a power factor and the total harmonic distortion ratio.
Abstract:
본 발명은 입력 전원을 사전에 설정된 직류 전원으로 변환하는 DC/DC 컨버터; 상기 DC/DC 컨버터로부터의 상기 직류 전원의 전압 레벨과 부하단에 인가되는 전압 레벨의 차이에 따라 스위칭 온 및 오프하여 상기 직류 전원의 출력을 제어하는 출력 제어부; 및 핫 스왑(hot swap)시 상기 DC/DC 컨버터의 소프트 스타트 동작을 시작시키고, 상기 출력 제어부가 스위칭 온되는 시점에 상기 DC/DC 컨버터의 소프트 스타트 동작을 중지시키는 제어부를 포함하는 전원 모듈 및 이를 갖는 다중 전원 공급 장치를 제안한다.
Abstract:
PURPOSE: A power supplier is provided to reduce conduction loss of a second side rectifier element by controlling the switching of the second side rectifier element based on a first side current. CONSTITUTION: A switching unit switches an input power. A transformation unit transforms the switched power. A rectifying unit (130) has a rectifier element. A control unit (140) controls the switching of the switching unit. A switching control unit (150) turns on and turns off the rectifier element. [Reference numerals] (141) Detection unit; (142) Switching signal generation unit; (151a) Resonance current detection unit; (151b) Magnetization current detection unit; (152) Rectification switching control unit
Abstract:
PURPOSE: A current command value generation method for estimating a maximum power point of a solar energy generation system and an apparatus using the same are provided to calculate output voltage only using a voltage detector, thereby generating a current command value. CONSTITUTION: A voltage detector detects input voltage of a fly-back power conversion part. A first operation unit computes output power from the detected input voltage. A second operation unit computes a power change amount based on the computed output power. The second operation unit computes a voltage change amount of the input voltage. A current command value generating unit(360) creates a current command value. The current command value estimates a maximum power point of a solar cell module.
Abstract:
본 발명은 이중 보빈 구조를 채택하고 이차측 권선을 외부에 연장되는 금속판으로 구성함으로써 제조 공정이 간소화되고, 방열 특성이 개선되며, 절연 특성이 향상된 트랜스포머 및 이를 갖는 전자 장치에 관한 것으로, 일차 권선을 외곽에 형성하여 일차 권선의 방열을 용이하게 하고, 이차 금속판이 내부에 형성되지만 연장부를 구비하여 이차 금속판의 방열이 용이하게 할 수 있다. 또한, 외부 보빈과 내부 보빈의 이중 보빈 구조를 채택하여 일차 권선과 이차 금속판간의 절연 거리를 확보하여 절연 기능을 향상시켰으며, 이차측을 미리 제조된 금속판으로 형성하여 제조 공정을 간소화할 수 있다.