DC Bus Voltage Regulation Strategy in Maritime DC Power System for Minimized Converter Loss

Author(s):  
Jonghun Yun ◽  
Young-kwang Son ◽  
Hyung-June Cho ◽  
Seung-Ki Sul AE
Aerospace ◽  
2020 ◽  
Vol 7 (7) ◽  
pp. 94
Author(s):  
Juan J. Rojas ◽  
Yamauchi Takashi ◽  
Mengu Cho

The lean satellite approach requires aggressive measures for cutting development time and resource utilization; therefore, the power system should be simple, with a low part count, high reliability, and good electrical performance. The fully-regulated bus direct energy transfer (FRDET) architecture is considered the most common solution for big satellites; however, it is rarely used in lean satellite designs because of its complexity and the lack of commercial off-the-shelf solutions. Based on this, a new implementation of the FRDET architecture was proposed, prototyped, and evaluated. The system was based on a bidirectional converter that charges and discharges the battery while maintaining the bus voltage regulation. The system was evaluated by comparing it with the prevailing architectures in the field, in terms of efficiency and average harvested solar power per orbit. The proposed system was superior in both aspects which made it more suitable for its application in lean satellite designs.


2018 ◽  
Vol 8 (9) ◽  
pp. 1525
Author(s):  
Ahmad M. A. Malkawi ◽  
Luiz A. C. Lopes

DC bus voltage signaling (DBS) and droop control are frequently employed in DC nano and microgrids with distributed energy resources (DERs) operating in a decentralized way. This approach is effective in enforcing the desired contributions of power sources and energy storage systems (ESSs) in steady-state conditions. The use of supercapacitors (SCs) along with batteries in a hybrid energy storage system (HESS) can mitigate the impact of high and fast current variations on the losses and lifetime of the battery units. However, by controlling the HESS as a single unit, one forfeits the potential contribution of the SC and its high power capabilities to dynamically improve voltage regulation in a DC nanogrid. This paper discusses an approach where the SC interface is controlled independently from the battery interface, with a small droop factor and a high pass filter (HPF), to produce high and short current pulses and smooth DC bus voltage variations due to sudden power imbalances in the DC nanogrid. Experimental results are presented to show that, unlike in a conventional HESS, the SC unit can be used to improve the dynamic voltage regulation of the DC nanogrid and, indirectly, mitigate the high and fast current variations in the battery.


2013 ◽  
Vol 448-453 ◽  
pp. 1727-1731
Author(s):  
Xi Yun Yang ◽  
Li Xia Li ◽  
Ya Min Zhang

The DC bus voltage is key variable for the operation of converter system in a wind power system. When grid voltage drops, a control of the DC bus voltage is needed to keep the smoothness of DC bus voltage for avoiding generator cutting off grid. A combined control method based on the grid voltage information feedforward with a crowbar circuit is proposed for a direct-drive wind power system in the paper. The unbalanced energy of the DC bus can be unleashed by the crowbar circuit during the dropping of grid voltage. At the same time, the output power of motor-side converter can be controlled to decrease according to the grid-side voltage information, and the mechanical speed of wind turbine and generator can be suppressed by the pitch angle regulation when the output power reduces. Thus, the DC-bus voltage can keep smooth. Results based on Matlab/Simulink simulation shows that this method not only improves dynamic response performance of DC bus voltages control, but also reduces the action time of crowbar circuit. It is benefit to the ability of the wind power system riding through the grid fault.


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