Review on LLC Converter Based on Hold-up

doi:10.11985/2021.02.015

Abstract

Abstract:

LLC converters have been widely used in recent years because of their soft switching advantages. Traditional LLC converters use variable frequency control. It is difficult to achieve a wide voltage input when the switching frequency range is constrained. As a result, LLC converter has a short hold-up time after power failure, and is limited in applications such as UPS. In response to this kind of problem, many domestic and foreign research results of wide-voltage input range LLC converters that can be used for hold-up emerge. The problems of the narrow range of the traditional LLC gain are analyzed, the research results from the control strategy and circuit structure are summarized, and the advantages and disadvantages of them are analyzed.

Key words: LLC, soft-switching, hold-up time, wide voltage input range

CLC Number:

TM46

XIONG Xuan, ZHAO Hui, CHEN Zongxiang. Review on LLC Converter Based on Hold-up[J]. Journal of Electrical Engineering, 2021, 16(2): 115-121.

Figures/Tables 16

References 36

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改进方案		参数				优缺点
种类	关键点	额定电压/功率/(V/W)	输入电压范围/V	开关频率范围/kHz	谐振频率/kHz	优缺点
控制策略	调节PFC^[13,14]	310.5/1 000	320~420	~200	200	无需附加电路,但可调范围有限
	不对称控制^[15]	18.5/85	300~400	61~100	100	不对称控制引起偏置电流
	全桥半桥切换^[17]	500/2 000	125~550	40~120	60	参数设计相对复杂
初级侧网络	初级侧附加开关^[19]	20/50	85~340	~500	500	开关管过多,控制相对复杂
	初级侧附加开关^[20]	385/6 600	225~378	90	78	开关管过多,控制相对复杂
	Boost前级^[21]	15/300	36~72	80~100	100	不对称控制引起偏置电流
	交错Boost前级^[22]	24/600	120~240	~100	100	不对称控制引起偏置电流
副边整流器	附加绕组^[23]	311/300	25~42	~130	130	变压器相对较大
	整流器切换^[25]	400/1 500	100~420	94.37~236.6	170	增益较大,但参数设计相对复杂
	四倍整流切换^[26]	400/1 500	100~500	70~150	100	增益较大,但参数设计相对复杂
	副边短路^[27]	200/300	250~400	34~75	75	电路结构改变小,切换过程没有过大的过冲问题,并控制简单
	副边短路^[28]	12/300	250~400	120~200	200	电路结构改变小,切换过程没有过大的过冲问题,并控制简单
谐振腔	附加变压器^[29]	210/250	25~100	80~140	140	切换过程有较大的过冲问题,参数设计也相对复杂
	可变电感^[32]	56/350	290~405	75~110	110
	可变电容^[33]	56/350	325~385	34~106	90
	谐振腔附加开关^[35]	12/300	250~400	150~260	260	不对称控制引起偏置电流
	谐振腔附加开关^[36]	48/1 000	200~390	70~100	100	增益较大,控制简单