引用本文: | 张勤进,张博,刘彦呈,等.基于低频电流注入的船舶直流微电网线路阻抗检测[J].电力系统保护与控制,2020,48(8):134-140.[点击复制] |
ZHANG Qinjin,ZHANG Bo,LIU Yancheng,et al.A line impedance detection of a ship DC microgrid based on low frequency current injection[J].Power System Protection and Control,2020,48(8):134-140[点击复制] |
|
摘要: |
下垂控制是船舶直流微电网中一种实现系统能量分配的有效方法。在传统下垂控制中,系统内各微源之间线路阻抗不一致,导致各分布式微源承担的功率也不一致,严重时微源直流变换器甚至出现过载故障。为了解决船舶直流微电网中由线路阻抗引起的负载均流精度问题,提出利用低频注入来检测线路阻抗的方法。通过在电感电流上注入低频交流信号,检测注入后的变换器电压、电流信息,利用傅里叶变换求得线路阻抗值,进一步补偿下垂系数。该方法可以提高微电网系统直流母线电压质量,改善直流变换器并联均流时的负载均分效果,对系统稳定运行影响小。最后仿真结果验证了该方法的有效性。 |
关键词: 直流微电网 负载均分 线路阻抗检测 低频注入 |
DOI:10.19783/j.cnki.pspc.190590 |
投稿时间:2019-05-24修订日期:2019-11-12 |
基金项目:国家自然科学基金项目(51709028,51979021);辽宁省自然科学基金项目(20170540082);中央高校基本科研业务费专项资金资助(3132019317) |
|
A line impedance detection of a ship DC microgrid based on low frequency current injection |
ZHANG Qinjin,ZHANG Bo,LIU Yancheng,ZHUANG Xuzhou,LIU Hongliang,LIU Qiang |
(Marine Engineering College, Dalian Maritime University, Dalian 116026, China;Shanghai Merchant Ship Design and Research Institute, Shanghai 201203, China) |
Abstract: |
Droop control is an effective method for realizing system energy distribution of a ship DC microgrid. In traditional droop control, the line impedance between the micro-sources in the system is inconsistent, which leads to inconsistency of the power of the distributed micro-sources. In serious cases, the micro-source DC converter even can suffer overload failure. To solve the problem of load current sharing accuracy caused by line impedance in a marine DC microgrid, a method of detecting line impedance by low frequency injection is proposed. This is achieved by injecting low-frequency AC signals into the inductance current, detecting the converter voltage and current information after injection, and obtaining line impedance by Fourier Transform. Then the droop gains can be compensated. This method can enhance the voltage quality of the DC bus in a microgrid system, improve the load sharing effect of a DC converter in parallel current sharing, and exert little influence on the stable operation of the system. Finally, the simulation results verify the effectiveness of the proposed method. This work is supported by National Natural Science Foundation of China (No. 51709028 and No. 51979021), Natural Science Foundation of Liaoning Province (No. 20170540082), and the Fundamental Research Funds for the Central Universities (No. 3132019317). |
Key words: DC microgrid load sharing line impedance detection low frequency injection |