Operating Voltage and Loss Analysis of a Bi-Directional Isolated DC/DC Converter
Operating Voltage and Loss Analysis of a Bi-Directional Isolated DC/DC Converter
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双向隔离 DC/DC 转换器的工作电压和损耗分析
DOI：
10.1541/ieejias.127.189
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发表时间：
2007
影响因子：
--
通讯作者：
H. Akagi
中科院分区：
文献类型：
--
作者：
S. Inoue;H. Akagi
本文描述了图1所示的双向隔离DC/DC转换器，该转换器具有单位匝数比的高频Transformer，其中输入和输出DC电压彼此不同。很少有技术论文涉及不同直流电压下的DC/DC转换器。此外，没有技术论文证明了在不同直流电压下额定功率约为10 kW的DC/DC转换器的操作。然而，电压调节能力可以带来DC/DC转换器的应用领域的显著扩展。因此，本文分析了工作直流电压之间的关系，转移功率和功率损耗，以确定如何不同的两个直流电压可以从对方没有过度增加功率损耗。然后，在额定电压为360 V，10 kW和20 kHz的DC/DC转换器上进行实验，证明在不同的直流电压下稳定的双向功率流。文中还讨论了死区时间对系统运行性能的影响。图2显示了当一个直流电压固定在320 V，另一个直流电压在180 V和360 V之间调整时，传输功率PDC和理论损耗之间的计算关系。请注意，图2假设功率传输PDC为正，理论损耗由缓冲器损耗和IGBT导通损耗组成，不包括IGBT开关损耗和磁性元件损耗。计算是在缓冲电容Csnub = 0.01 μF且每个IGBT和二极管两端的电压降为1.5 V（与电流无关）的条件下进行的。E1和E2之间的差异缩小了可能进行ZVS（零电压开关）操作的传输功率范围，导致缓冲器损耗增加。E2越低，传输给定功率所需的电流越高，导致比E1 = E2 = 320 V时更大的功率损耗。基于E1 = E2 = 320 V时的理论损耗，图2中以虚线表示212 W的热极限。当E1 = 320 V且E2 = 180 V时，理论损耗在PDC = 5.6kW时达到热极限。DC/DC转换器的功率损耗或热设计决定了功率传输的可能范围以及两个DC电压之间的差异。如本文所述，电流i1的峰值也对可能的电压差施加限制。尽管存在上述增加的功率损耗，但是在不同直流电压下的操作是有用的，并且可以扩展dc/dc转换器的应用领域。将E1固定为320 V，将E2改变为320 V、360 V、260 V，图3示出了当5 kW的功率从桥2传输到桥1时的dc/dc转换器的实验波形（PDC = −5 kW），E1 = 320 V，E2 = 180 V。i1的峰值为60 A，而其理论值为66 A。虽然桥2是在硬切换图1中操作。一种双向隔离DC/DC变换器，
This paper describes the bi-directional isolated dc/dc converter shown in Fig. 1 having a high-frequency transformer with a unity turn ratio, where the input and output dc voltages are different from each other. Few technical papers have dealt with the dc/dc converter under different dc voltages. Besides, no technical paper has demonstrated the operation of the dc/dc converter rated around 10 kW under different dc voltages. However, voltage-adjusting capability may bring about a significant expansion of the application fields of the dc/dc converter. Thus, this paper analyzes the relationship between operating dc voltages, transfered power, and power loss to determine how different the two dc voltages can be from each other without excessively increasing power loss. Then, experiments are conducted on the dc/dc converter rated at 360 V, 10 kW, and 20 kHz, demonstrating bi-directional power flow under different dc voltages stably. The effect of the so-called “dead time” on the operating performance is also discussed in this paper. Fig. 2 shows the calculated relationship between transfered power PDC and the theoretical loss when one dc voltage is fixed at 320 V and the other is adjusted between 180 V and 360 V. Note that Fig. 2 assumes the power transfer PDC to be positive, and the theoretical loss consists of a snubber loss and an IGBT conducting loss excluding an IGBT switching loss and magnetic-component losses. The calculation was carried out under the condition where the snubber capacitor Csnub = 0.01 μF and the voltage drop across each IGBT and diode is 1.5 V regardless of the current. Difference between E1 and E2 narrows the range of transfered power where ZVS (zerovoltage switching) operation is possible, resulting in an increased snubber loss. The lower E2 becomes, the higher current is needed to transfer a given power, causing larger power loss than that at E1 = E2 = 320 V. Thermal limit of 212 W is drawn as a dashed line in Fig. 2 based on the theoretical loss at E1 = E2 = 320 V. When E1 = 320 V and E2 = 180 V, the theoretical loss reaches the thermal limit at PDC = 5.6 kW. The power loss or the thermal design of the dc/dc converter determines the possible range of power transfer and the difference between the two dc voltages. As is mentioned in this paper, the peak value of the current i1 also imposes limitation on the possible voltage difference. Despite the above-mentioned increased power loss, the operation under different dc voltages is useful and may expand the application field of the dc/dc converter. Experiments were conducted with E1 fixed to 320 V and E2 changed to be 320 V, 360 V, 260 V, and 180 V. Fig. 3 shows experimental waveforms of the dc/dc converter when a power of 5 kW is transfered from Bridge 2 to Bridge 1 (PDC = −5 kW) at E1 = 320 V and E2 = 180 V. The peak value of i1 was 60 A while its theoretical value was 66 A. Although Bridge 2 was operated in hard switching Fig. 1. A bi-directional isolated DC/DC converter
双向隔离DC/DC变换器作为下一代3.3kV/6.6kV电源变换系统的核心电路
DOI：
--
发表时间：
2006
期刊：
電気学会論文誌D 126巻3号
影响因子：
--
作者：
井上重徳;赤木泰文
通讯作者：
赤木泰文