摘要
在分析三相四线制二极管中点箝位型(NPC)三电平整流器小信号交流模型的基础上,以电网电流正弦且单位功率因数运行为目标,在dq0坐标系下,提出基于复矢量解耦的PI+谐振控制的电流控制策略,以零极点相消的方法设计PI控制器;引入2倍基波频率的谐振控制器,以抑制硬件参数分散性和电网电压不平衡导致的网侧负序和3次谐波电流。为了解决不平衡负载引起的整流器正负母线电压不均的问题,在总压控制环的基础上,将正负母线电压差作为反馈量构建均压控制环路,实现直流侧电压均衡。最后,在10 kW的三相四线制三电平整流器+逆变器平台上进行实验验证,结果表明,在提出的控制策略下,整流器网侧电流质量高,输出的直流母线电压稳定且均衡。
Based on the analysis of small signal AC model of three-phase four-wire three-level diode neutral-point clamped(NPC) rectifier, a current control method of PI+resonant controller based on complex vector decoupling is proposed, aiming at the sinusoidal current of power grid and the unit power factor. In a dq0 coordinate system, the dq components of the grid currents are cross-decoupled, and PI controllers of current loops are designed by the zero-pole cancellation method. In order to suppress negative sequence and third harmonic currents, which are caused by device parameter dispersion and unbalanced grid-side voltage, the resonant controller with two times fundamental frequency is connected in parallel with PI controllers. On the other hand, in order to solve the problem of unbalanced voltages in DC buses of rectifier caused by unbalanced loads, the voltage difference between the positive and negative buses is used as feedback to establish a voltage sharing control loop based on the total voltage control. At last, a 10 kW experimental platform of inverter fed by three-phase four-wire NPC rectifier is established. The experimental results show that currents on the grid side are superior in quality,and the voltages of both positive and negative DC buses are stable and balanced by the use of the proposed strategy.
作者
董德智
徐德鸿
DONG Dezhi;XU Dehong(School of Electrical Engineering,Zhejiang University,Hangzhou 310027,China;School of Electrical Engineering,Tongling College,Tongling 244000,China)
出处
《高电压技术》
EI
CAS
CSCD
北大核心
2021年第4期1363-1371,共9页
High Voltage Engineering
基金
安徽省高校自然科学重点研究项目(KJ2018A0476)
安徽省卓越人才培养创新项目(2020zyrc153)。
关键词
三相四线制三电平整流器
模型
复矢量
电流控制
均压控制
three-phase four-wire three-level rectifier
model
complex vector
current control
voltage sharing control
