• 한국산학기술학회논문지
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• 제11권7호
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• pp.2570-2578
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• 2010

본 논문에서는 임계전류도통모드로 동작하는 디지털제어 단상 역률개선(PFC; power-factor correction) 컨버터를 제안한다. 제안한 컨버터는 PFC를 위하여 DC-DC 부스트 컨버터 구조를 이용하며 인덕터전류를 임계도통모드로 동작시킨다. 또한 제안한 컨버터는 마이컴을 이용하여 디지털적으로 제어되기 때문에 제어회로는 간단해지고 컨버터는 더욱 효과적으로 동작한다. 본 논문에서는 먼저 제안한 컨버터의 동작원리를 설명하고 회로를 해석한다. 그리고 본 논문은 제안한 컨버터의 구현방법을 소프트웨어와 회로설계 부분으로 구분하여 구체적인 설계예와 함께 설명한다. 또한 설계된 회로파라미터에 의한 프로토타입 컨버터의 실험결과로 제안한 컨버터가 단상 PFC 컨버터로써 좋은 동작 특성을 가지고 있음을 보인다.

• 전력전자학회논문지
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• 제16권6호
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• pp.561-568
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• 2011

본 논문은 단상 이중변환 무정전전원장치를 위한 단일 스위치 배전압 방식의 단상 PFC 컨버터의 동작 특성을 기술한다. 단일 스위치 배전압 방식의 단상 PFC 컨버터는 브릿지 다이오드와 양방향 능동 스위치 한 개만이 필요하며 재료비 절감이 가능하다. 하지만 이 회로가 제안된 후 동작 특성 및 제어기 설계에 대한 연구결과가 알려지지 않았다. 본 논문에서는 동작 특성과 제어기 설계방법을 기술하고 성능평가를 위해 단상 정격 3kVA 이중변환 무정전전원장치를 대상으로 실험을 수행하였다. 또한 실험을 통해 입력전류 제어, 입력역률 보상 성능을 확인하였다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2000년도 전력전자학술대회 논문집
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• pp.163-167
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• 2000

This paper presents the digital control of single-phase power factor correction(PFC) converter which has the variable gain according to the condition of inner control loop error. Generally the gain of inner current control loop in single-stage PFC converter has a constant magnitude. This has a bad influence on the power factor because current loop doesn't operate smoothly in the condition that input voltage is low In particular a digital controller has more time delay than an analog controller and degrades This drops the phase margin of the total digital PFC system,. It causes the problem that the gain of current control loop isn't increased enough. In addition the oscillation happens in the peak value of the input voltage open loop PFC system gain changes according to ac input voltage. These aspects make the design of the digital PFC controller difficult The digital PFC controller presented in this paper has a variable gain of current control loop according to input voltage. The 1kW converter was used to verify the efficiency of the digital PFC controller.

• 전력전자학회논문지
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• 제17권1호
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• pp.1-7
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• 2012

This paper describes the performance comparison results for current controller of a single-phase PFC converter with 1-switch voltage doubler strategy for single-phase double-conversion UPS(Uninterruptible Power Supply). A single-phase PFC converter with 1-switch voltage doubler strategy needs a diode bridge and one bidirectional active switch. Thus it is possible to reduce the material cost. However, the study results of current controller design and comparison of current control method has not been known after the converter circuit was proposed. For the performance comparison of current control, single-phase 3 kVA double-conversion UPS was tested. The performance of PI and PR current controller is experimentally confirmed with followings - input current reference tracking, input power factor correction and input current THD suppression.

• 전력전자학회논문지
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• 제11권4호
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• pp.328-339
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• 2006

본 논문에서는 1 단구조방식의 PFC 회로를 갖는 단상 SRM 구동시스템의 특성해석에 대해 다룬다. 단상 SRM은 기계적 및 전기적 구조가 단순하고, 견고하며, 고속운전특성이 우수하다. 다이오드 브릿지 정류기와 직류링크회로의 커패시터로 구성된 종래의 단상 SRM 구동방식은 커패시터의 짧은 시간의 충 방전 전류에 의해 역률이 크게 저하되는 문제가 발생한다. 따라서, 본 논문에서는 우선 부가적인 능동회로가 없는 1 단방식의 PFC 회로에 대한 분석을 통하여 역률개선 및 토크리플 억제를 위한 스위칭 토플로지를 새로 제안한다. 제안한 스위칭 토플로지로 작동하는 PFC 회로를 갖는 단상 SRM 구동시스템을 구축하고 시스템에 대한 수치해석을 통해 운전속도, 부하토크 및 커패시터 용량에 따른 토크리플, 역률 및 효율 등 시스템의 특성을 얻으며, 이를 실제 실험결과와 비교한다.

• 한국산업정보학회논문지
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• 제21권4호
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• pp.21-30
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• 2016

In a single-phase power factor correction (PFC), the standard cascaded control algorithm using a proportional-integral-derivative (PID) controller has two main drawbacks: an inability to track sinusoidal current reference and low harmonic compensation capability. These drawbacks cause poor power factor and high harmonics in grid current. To improve these drawbacks, this paper uses a proportional-integral-derivative-resonant (PIDR) controller which combines a type-III PID with proportional-resonant (PR) controllers in the PFC. Based on a small signal model of the PFC, the type-III PID controller was implemented taking into account the bandwidth and phase margin of the PFC system. To adopt the PR controllers, the spectrum of inductor current of the PFC was analyzed in frequency domain. The hybrid PIDR controller were simulated using PSCAD/EMTDC and implemented on a 3 kW PFC prototype hardware. The performance results of the hybrid PIDR controller were compared with those of an individual type-III PID controller. Both controllers were implemented successfully in the single-phase PFC. The total harmonic distortion of the proposed controller were much better than those of the individual type-III PID controller.

• Journal of Power Electronics
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• 제17권1호
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• pp.31-40
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• 2017

A novel voltage-fed single-stage power factor correction (PFC) full-bridge converter based on asymmetric phase-shifted control for battery chargers is proposed in this paper. The attractive feature of the proposed converter is that it can operate in a wide output voltage range without an output low-frequency ripple, which is indispensable in battery charger applications. Meanwhile, the converter can maintain a high power factor and a controllable dc bus voltage over a wide output voltage range. In this paper, the realization of PFC and the operation principle of asymmetric phase-shifted control are given. A small-signal analysis of the proposed single-stage power factor correction (PFC) full-bridge converter is performed. Experimental results obtained from a 1kW experimental prototype are given to validate the feasibility of the proposed converter. The PF is higher than 0.97 over the entire output voltage range with the proposed control strategy.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.240-243
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• 2001

This paper presents the digital controller using variable gain for single-phase power factor correction (PFC) converter. Generally, the gain of inner current control loop in single-stage PFC converter has a constant magnitude. This is why input current is distorted under low input voltage. In particular, a digital controller has more time delay than an analog controller which degrades characteristics of control loop. So, it causes the problem that the gain of current control loop isn't increased enough. In addition, the oscillation happens in the peak value of the input voltage open loop PFC system gain changes according to ac input voltage. These aspects make the design of the digital PFC controller difficult. In this paper, the improved digital control method for single-phase power factor converter is presented. The variable gain according to input voltage and input current help to improve current shape. The 800W converter is manufactured to verify the proposed control method.

• 전력전자학회논문지
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• 제22권6호
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• pp.496-503
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• 2017

This study proposes a high-performance current control algorithm for a diode-bridge-type single-phase boost power factor correction (PFC) converter. The conventional asynchronous single-phase current controllers that directly control AC-type current tend to be accompanied by steady-state errors due to their poor dynamic characteristics for the transient-state, which can be attributed to bandwidth limitations and phase delays. In the proposed algorithm, an ideal current control with minimal phase delays and steady-state errors can be achieved by using a virtual DQ synchronous reference frame and by controlling the synchronous reference frame excluding the frequency component in the single-phase system. The performance of the conventional asynchronous single-phase current controller is compared with that of the proposed algorithm through simulation and experiments, and the results have confirmed the superiority of the latter.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 B
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• pp.1214-1216
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• 2004

Conventional Switched Mode Power Supplies(SMPS) with diode-capacitor rectifier have distorted input current waveform with high harmonic contents. Typically, these SMPS have a power factor lower than 0,65. To improve with this problem the power factor correction(PFC) circuit of power supplies has to be introduced. PFC circuit have tendency to be applied in new power supply designs. The input active power factor correction circuits can be implemented using either the two-stage or the single-stage approach. In this paper, the comparative analysis of power factor correction circuit using feedforward control with average current mode single-stage flyback method converter and two-stage converter which is combination of boost and flyback converter. The two prototypes of 50W were designed and tested a laboratory experimental. Also, the comparative analysis is confirmed by simulation and experimental results.