隔离型交-直流固态变压器前后级协调控制对比

doi:10.16180/j.cnki.issn1007-7820.2022.07.013

摘要/Abstract

摘要：

隔离型交-直流固态变压器广泛采用双向变换器的前后多级级联结构。由于前后级控制带宽存在不同,导致两级传递功率存在不同。功率突变时,该差异会威胁此类SST的运行安全。针对此问题,文中分析了级间功率差异的产生机理,对各类减少级间功率波动的控制策略进行归纳整理,推导了不同策略下负载扰动对两级间电压的数学模型,利用MATLAB得到了各类典型控制策略的闭环波特图与时域下对应的阶跃响应,并横向对比了各类策略的优势与不足。仿真及实验结果证明了分析比较结果的正确性和有效性。

关键词: 固态变压器, 双向变换器, 控制带宽, 级间功率差异, 负载扰动, 波特图, 阶跃响应, 横向对比

Abstract:

Isolated AC-DC solid-state transformers widely use the front and rear multi-stage cascade structure of the bidirectional converter. Due to the difference in the control bandwidth of the front and rear stages, the transmission power of the two stages is different. When the power suddenly changes, the difference will seriously threaten the operational safety of this type of SST. In view of this problem, this study analyzes the mechanism of the power difference between the stages, summarizes various control strategies to reduce the power fluctuations between the stages, and derives the mathematical model of the load disturbance on the voltage between the two stages under different strategies. Using MATLAB, the closed-loop Bode plots of various typical control strategies and the corresponding step responses in the time domain are obtained, and the advantages and disadvantages of various strategies are compared horizontally. Finally, simulation and experiment results verify the correctness and validity of the analysis and comparison results.

Key words: solid-state transformer, bidirectional converter, control bandwidth, power difference between stages, load disturbance, Bode plot, step response, horizontal contrast

中图分类号:

郑征,姜鹏飞,张国澎,李子汉. 隔离型交-直流固态变压器前后级协调控制对比[J]. 电子科技, 2022, 35(7): 79-86.

ZHENG Zheng,JIANG Pengfei,ZHANG Guopeng,LI Zihan. Comparison of Coordinated Control between Front and Rear Stages of Isolated AC-DC Solid-State Transformers[J]. Electronic Science and Technology, 2022, 35(7): 79-86.

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参数	数值	参数	数值
u_s/V	380	u_o_ref/V	750
L_s/mH	2	f_c/Hz	5k
C₁/mH	1.5	L_r/μH	20
u_dcref/V	700	n	1∶4
C₂/mH	2.2	f_s/Hz	10k
R₁/Ω	10	u_o/V	750
u_dc/V	700	R₂/Ω	2

参数	数值	参数	数值
k_pd	0.25	k_id	3.00
k_pi	15.00	k_ii	525.00
k_po	0.01	k_io	0.40

参数	数值	参数	数值
u_s/V	50	R₂/Ω	2
L_s/mH	2	f_c/kHz	5
C₁/mH	2	L_r/μH	20
u_dcref/V	70	n	1∶4
C₂/mH	1.5	f_s/kHz	10
R₁/Ω	10

参数	数值	参数	数值
k_pd	0.300	k_id	8.000
k_pi	5.000	k_ii	105.000
k_po	0.005	k_io	0.200

功率切换 (正→负)	传统控制	交错前馈控制	直接前馈控制	间接前馈控制	依次前馈控制
Δu_dc	20.0 V	4.5 V	6.0 V	14.0 V	16.0 V
Δt	0.300 s	0.075 s	0.100 s	0.150 s	0.200 s