Abstract：Vienna rectifier is one of the most potential topologies for aircraft electrical systems due to its high power density, high efficiency, and high reliability. With the onboard electrical equipment increasing, the electrical power consumption increases significantly in more-electrical aircraft, resulting in harmonics and grid unbalanced issues in aircraft electrical systems. Three-phase rectifiers must maintain stable operation under unbalanced grid and lack phase condition, which presents a challenge to the control strategy of the Vienna rectifier. According to the instantaneous symmetrical component, the unbalanced grid voltage comprises fundamental positive-, negative- and zero-sequence components. The negative-sequence component leads to second-harmonic ripples in dc-link voltage and low-order harmonics in input currents. The mathematical model of the Vienna rectifier under unbalanced conditions is derived. DSOGI-PLL is utilized to calculate positive- and negative- sequence components of the grid and generate current references. In this way, input current harmonics and dc-link voltage ripples are suppressed well under the unbalanced grid. For higher reliability requirements, the application under the grid lack phase should be considered. Under a lack-phase grid, the conventional three-phase control strategy is invalid. Rectifiers usually detect the lack-phase fault condition and shutdown for protection, which decreases the reliability of the electrical system. In order to make Vienna rectifiers maintain stable output under a lack-phase grid, this paper first analyzes the mathematical model. The rectifier under the lack-phase grid is regarded as a single-phase PWM rectifier. By analyzing operational modes, a single-phase space vector pulse width modulation method is proposed, and the implementation process is introduced in detail. Different operational modes can be seen as seven basic voltage vectors, divided into zero, short, and long vectors according to the vector length. Like conventional three-phase space vector modulation, seven basic voltage vectors are used to synthesize the reference voltage vector. Not all switch combinations for each vector can be achieved at each moment, and four sectors are divided for exact synthetization. The dwell time for each basic vector satisfies the voltage-second balance principle. The vectors sequence is selected to be a five-segment form for minimizing the switching loss. The voltage of output capacitors can be balanced by adjusting the dwell times of a pair of redundant short vectors. Furthermore, according to the three-phase voltage sampling conditions under a lack-phase grid, a lack-phase fault detection method based on the phase locked loop is proposed. Different grid fault conditions can be determined by calculating the positive- and negative-sequence components of sampling grid voltages. The corresponding control loop is also designed for stable dc output under lack-phase conditions. If the grid voltages are three-phase input, a control strategy for the unbalanced grid is applied. If a lack-phase fault occurs, the corresponding control strategy is switched for lack phase control. A 4.5 kW aircraft Vienna rectifier prototype is built to verify the proposed control strategy. Experiment results prove that the Vienna rectifier can maintain stable operation under the unbalanced grid and lack-phase grid with the proposed control strategy.
[1] Wheeler P.Technology for the more and all electric aircraft of the future[C]//2016 IEEE International Conference on Automatica (ICA-ACCA), Curico, Chile, 2016: 1-5. [2] Chen Jiawei, Wang Chengjun, Chen Jie.Investigation on the selection of electric power system architecture for future more electric aircraft[J]. IEEE Transactions on Transportation Electrification, 2018, 4(2): 563-576. [3] Ren Xiaoyong, Zhou Yuting, Guo Zhehui, et al.Analysis and improvement of capacitance effects in 360-800 Hz variable on-time controlled CRM Boost PFC converters[J]. IEEE Transactions on Power Elec- tronics, 2020, 35(7): 7480-7491. [4] 周运红, 张爱民, 黄晶晶, 等. 基于动态事件触发的Vienna整流器模型预测控制[J]. 电工技术学报, 2022, 37(8): 2040-2050. Zhou Yunhong, Zhang Aimin, Huang Jingjing, et al.Dynamic event-triggered model predictive control for Vienna rectifier[J]. Transactions of China Electro- technical Society, 2022, 37(8): 2040-2050. [5] 陈杰, 沈禹廷, 沈佳茜, 等. 三相VIENNA整流器的混合空间矢量脉宽调制策略[J]. 电工技术学报, 2021, 36(增刊2): 665-675. Chen Jie, Shen Yuting, Shen Jiaqian, et al.Hybrid space vector pulse width modulation strategy for three-phase VIENNA rectifier[J]. Transactions of China Electrotechnical Society, 2021, 36(S2): 665-675. [6] 肖蕙蕙, 苏新柱, 郭强, 等. 三相Vienna整流器无网压传感器预测电流控制策略[J]. 电工技术学报, 2021, 36(6): 1304-1312. Xiao Huihui, Su Xinzhu, Guo Qiang, et al.Predictive current control of three-phase Vienna rectifier without grid voltage sensors[J]. Transactions of China Electro- technical Society, 2021, 36(6): 1304-1312. [7] Kolar J W, Zach F C.A novel three-phase utility interface minimizing line current harmonics of high- power telecommunications rectifier modules[J]. IEEE Transactions on Industrial Electronics, 1997, 44(4): 456-467. [8] Gong G, Heldwein M L, Drofenik U, et al.Comparative evaluation of three-phase high-power- factor AC/DC converter concepts for application in future more electronic aircraft[J]. IEEE Transactions on Industrial Electronics, 2005, 52(3): 727-737. [9] Chen Xudong, Ren Xiaoyong, Zhang Zhiliang, et al.Dynamic response optimization for three-phase Vienna rectifier with load feedforward control[C]// 2016 IEEE Energy Conversion Congress and Exposi- tion, Milwaukee, 2017: 1-7. [10] Enjeti P N, Choudhury S A.A new control strategy to improve the performance of a PWM AC to DC con- verter under unbalanced operating conditions[J]. IEEE Transactions on Power Electronics, 1993, 8(4): 493-500. [11] Rodriguez P, Pou J, Bergas J, et al.Decoupled double synchronous reference frame PLL for power con- verters control[J]. IEEE Transactions on Power Electronics, 2007, 22(2): 584-592. [12] Teshnizi H M, Moallem A, Zolghadri M, et al.A dual-frame hybrid vector control of vector modulated VIENNA I rectifier for unity power factor operation under unbalanced mains condition[C]//IEEE Applied Power Electronics Conference, Austin, TX, USA, 2008: 1402-1408. [13] Rodríguez P, Luna A, Muñoz-Aguilar R S, et al. A stationary reference frame grid synchronization system for three-phase grid-connected power con- verters under adverse grid conditions[J]. IEEE Transa- ctions on Power Electronics, 2012, 27(1): 99-112. [14] Burgos R, Lai Rixin, Pei Yunqing, et al.Space vector modulator for Vienna-type rectifiers based on the equivalence between two- and three-level converters: a carrier-nased implementation[J]. IEEE Transactions on Power Electronics, 2008, 23(4): 1888-1898. [15] Hang Lijun, Li Bin, Zhang Ming, et al.Equivalence of SVM and carrier-based PWM in three-phase/wire/ level Vienna rectifier and capability of unbalanced- load control[J]. IEEE Transactions on Industrial Electronics, 2014, 61(1): 20-28. [16] RTCA. DO-160G-2010. Environmental conditions and test procedures for aircraft equipment[M]. Washington USA: TRCA, 2010. [17] Kolar J W, Friedli T.The essence of three-phase PFC rectifier systems-part I[J]. IEEE Transactions on Power Electronics, 2013, 28(1): 176-198. [18] 王达开, 常越, 王娇娇, 等. 变频器缺相故障检测及相序自适应方法[J]. 电机与控制应用, 2018, 45(8): 110-115, 123. Wang Dakai, Chang Yue, Wang Jiaojiao, et al.Phase- loss detection and phase-sequence adaption method of frequency converter[J]. Electric Machines and Control Application, 2018, 45(8): 110-115,123. [19] 王栋, 刘利. 一种基于单片机的相序检测及电机缺相保护方法[J]. 电机与控制应用, 2006, 33(9): 50-52. Wang Dong, Liu Li.A novel method for phase dequence test and phase-break protection based on MCU[J]. Electric Machines & Control Application. 2006, 33(9): 50-52. [20] Zhang Xianjin, Fan Caihong.Research on 3-phase 4-wire VIENNA rectifier based on one cycle control[C]//2012 Fifth International Conference on Intelligent Computation Technology and Automation, Zhangjiajie, China, 2012: 280-282. [21] 张志, 谢运祥, 乐江源, 等. 二极管钳位型单相三电平逆变器空间矢量脉宽调制方法[J]. 中国电机工程学报, 2010, 30(27): 62-68. Zhang Zhi, Xie Yunxiang, Le Jiangyuan, et al.Study of SVPWM method for single-phase three-level diode-clamped inverter[J]. Proceedings of the CSEE, 2010, 30(27): 62-68. [22] 王建华, 骆芳芳, 季振东, 等. T型三电平变换器的通用PWM平均模型[J]. 中国电机工程学报, 2018, 38(2): 573-581, 688. Wang Jianhua, Luo Fangfang, Ji Zhendong, et al.A unified PWM averaged model for T-type three-level converter[J]. Proceedings of the CSEE, 2018, 38(2): 573-581, 688. [23] Hang Lijun, Zhang Hao, Liu Sensen, et al.A novel control strategy based on natural frame for Vienna- type rectifier under light unbalanced-grid condi- tions[J]. IEEE Transactions on Industrial Electronics, 2015, 62(3): 1353-1362. [24] Zhang Ming, Hang Lijun, Yao Wenxi, et al.A novel strategy for three-phase/switch/level (Vienna) recti- fier under severe unbalanced grids[J]. IEEE Transa- ctions on Industrial Electronics, 2013, 60(10): 4243-4252.
2023, Vol. 38 
