具前端脈波幅度調變控制之串聯諧振轉換器的設計

Design of a Serial Resonant Converter with Front-End PAM Control

李英竹(Ying-Zhu Lee)

指導教授 ： 黃明熙

國立臺北科技大學/電資學院/電資碩士在職專班研究所/碩士(2012年)

https://doi.org/10.6841/NTUT.2012.00340

摘要

本論文是以具功率因數修正與電氣隔離之交流-直流轉換器的高效率化作為研究目標，所提系統由一單相主動功率因數修正之整流模組及串接一串聯諧振轉換器所建構。所提單相具功率因數修正整流模組之輸出電壓會依據輸入電源之電壓進行調控，其範圍從200V至400V，如此可有效提升該模組於不同電源電壓之效率，此法對提升串聯諧振轉換器之效率亦有助益。而串聯諧振轉換器為LLC架構，是以固定50%責任週期的互補驅動信號來調變半橋功率晶體之切換頻率，使變壓器初級側漏電感、激磁電感、諧振電容及功率元件MOSFET上的寄生元件產生諧振現象，達到一次側開關的零電壓及二次側開關的零電流切換來降低元件的切換損失，如此可有效提高系統效率；最後於變壓器二次側加入同步整流使系統之效率進一步提升。
所提之轉換器是以一只數位訊號處理器做為控制核心同時驅動所有功率晶體，並建構具110V輸入與400W/12V輸出轉換器作為載具，驗證所提控制策略之有效性。實測結果，當直流鏈電壓由400V降壓至350V，在不同負載條件下交流-直流轉換器效率可提高約2.55%∼5.06%，而串聯諧振轉換器之效率約可提高2.0%∼6.3%，結果符合預期。

關鍵字

功率因數修正 ； 串聯諧振轉換器 ； 脈波高度調變 ； 數位功率控制

並列摘要

The object of this thesis is to design a high efficiency AC-DC converter with power factor correction and electrical isolated DC-DC converter. The proposed converter consists of two stages, including a single phase AC-DC rectifier with power factor correction and a serial resonant converter(SRC) connected in series. The output voltage of the PFC AC-DC converter can be changed from 200V to 400V according to input line voltage, so it can improve efficiency of the converter under different input voltage. Moreover, the efficiency of SRC may also be enhanced. The SRC was constructed from LLC resonant tank which is driven by a half-bridge circuit with fixed 50%-duty carrier frequency. Hence the resonant phenomenon was occurred by both leakage inductance of primary coil and the magnetizing inductance of the transformer, the resonant capacitor and parasitic component of power MOSFETs. The ZVS on primary side power MOSFETs and the ZCS on secondary side power MOSFETs can be achieved to reduce the switching loss, therefore the efficiency of SRC can be yielded. Finally, synchronous rectifier was added in the secondary side of transformer to improve the efficiency further.
The proposed converter with 110V input and 400W/12V output was built and controlled by a DSP. All the power MOSFETs are driven by the DSP. The experimental results, which are successful to meet the expectations, show that the efficiency will be increased about 2.55% to 5.06% for AC-DC converter and about 2.0% to 6.3% for SRC when the DC-link voltage is reduced from 400V to 350V under different loaded conditions.

並列關鍵字

Power factor correction ； Series resonant converter ； Pulse amplitude Modulation ； Digital power control

參考文獻

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