Fault Localization Strategy for Modular Multilevel Converters Under Submodule Lower Switch Open-Circuit Fault

Liu, Chengkai; Deng, Fujin; Qian, Heng; Zhu, Rongwu; Liserre, Marco; Wang, Zheng; Wu, Chaozhong

doi:10.1109/tpel.2019.2941129

Cited by 55 publications

(18 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Modular Multilevel Converter (MMC) [1] -based high voltage direct current (HVDC) transmission is the preferred scheme for grid integration of large-scale long-distance offshore wind farms, as shown in Figure 1, thanks to its modularity, scalability, high efficiency, [2], [3], etc. In the last The associate editor coordinating the review of this manuscript and approving it for publication was Zhixiang Zou .…”

Section: Introductionmentioning

confidence: 99%

Generalized MIMO Sequence Impedance Modeling and Stability Analysis of MMC-HVDC With Wind Farm Considering Frequency Couplings

et al. 2020

View full text Add to dashboard Cite

Recently, small-signal stability of the modular multilevel converter (MMC) based high-voltage direct current (HVDC) transmission for wind farm integration has attracted great attentions. The impedance-based frequency-domain method is an effective tool for such studies, in which the accuracy of the impedance model is of significant importance. Currently, the decoupled single-input single-output (SISO) sequence impedance of the MMC-HVDC system with wind farm is commonly used due to the simplicity in stability analysis. However, since both the MMC and wind farm exhibit frequency coupling behaviors, the decoupled SISO sequence impedance model may lead to inaccurate stability conclusion under certain conditions. In order to improve the model accuracy, based on the harmonic state-space (HSS) modeling approach, this paper proposes a generalized multi-input multi-output (MIMO) sequence impedance model of the MMC-wind farm system. The proposed MIMO impedance model can effectively capture the frequency couplings in the interconnected system, based on which the coupling mechanism of multi-frequency components within the MMC is then revealed. To facilitate the interconnection analysis, the model truncation criteria is proposed and validated by comparing the accuracy of the MIMO model with different truncated dimensions. In addition, this paper considers the internal impedance network of the wind farm when developing the aggregated wind farm impedance model for interaction stability analysis. Finally, the proposed MIMO sequence impedance model is applied to accurately predict the instability of the MMC-HVDC connected wind farm system.

show abstract

Section: Introductionmentioning

confidence: 99%

Generalized MIMO Sequence Impedance Modeling and Stability Analysis of MMC-HVDC With Wind Farm Considering Frequency Couplings

et al. 2020

View full text Add to dashboard Cite

show abstract

“…Once the faulty sub-module is detected, the corresponding arm will lose the voltage level. This paper focus is on FTO, so advanced works on fault detection can be found in [8]- [10], [30]- [33]. Let F max be maximum of (F a , F b , and F c ).…”

Section: B Fault Detection Techniquementioning

confidence: 99%

DC Voltage Control and OLTC Control Strategy for MMC-Based HVDC System Under SM Failure

2021

View full text Add to dashboard Cite

The Modular multilevel converters (MMCs) have excellent performance when operated with high modulation index such as the case of gird-connected converters in high voltage direct current (HVDC) system. Reliable and fault tolerant operation (FTO) of the system is very important in HVDC. A novel FTO algorithm under sub module failure without using any additional redundant SMs is proposed. In the proposed method, the direct current bus voltage control and on-load tap changer (OLTC) control strategy are combined for interruption free operation of the system without any additional voltage stress on switching devices and performance degradation of the system during fault. The analytical details of the normal as well as FTO operation are given. The proposed FTO strategy is verified through simulation and also experimentally using a prototype. The simulation and experimental results are presented. INDEX TERMSfault tolerant operation (FTO). high voltage direct current (HVDC), On load tap changer (OLTC), Multi-level converters(MLCs), modular multilevel converter (MMC), pulse width modulation (PWM), voltage source converters (VSC), sub module (SM) failure

show abstract

“…Fig. 1(b) illustrates the i-th (i=1, 2……n) SM in the upper arm in phase A, which includes the top IGBT/diode (T1/D1), the bottom IGBT/diode (T2/D2), and the capacitor Caui [17]. Normally, the i-th SM is dominated by i-th drive signal Saui as 12 12 1, is on and is off 0, is off and is on…”

Section: A Structure Of Mmcsmentioning

confidence: 99%

Thermal Optimization Strategy Based on Second-Order Harmonic Circulating Current Injection for MMCs

Zhao

Deng

et al. 2021

IEEE Access

Self Cite

View full text Add to dashboard Cite

Thermal management is one of the most significant challenges for reliability improvement of modular multilevel converters (MMCs). The thermal stress difference caused by the uneven loss distribution between top and bottom IGBTs/diodes will lead to lifetime difference of the IGBTs/diodes which will decrease the reliability of the MMC. In this paper, a thermal optimization strategy for MMCs is proposed, where the maximum thermal stress in the IGBT/diode of each SM can be effectively reduced through injecting optimum second-order harmonic current into the circulating current of MMCs, and accordingly the lifetime of MMCs can be improved by the proposed strategy. Detailed simulation results with PSCAD software and experimental results with 3kW MMC platform are provided to confirm the validity of the proposed thermal optimization strategy for MMCs. INDEX TERMSCirculating current injection, Modular multilevel converters, lifetime, thermal optimization.

show abstract

Fault Localization Strategy for Modular Multilevel Converters Under Submodule Lower Switch Open-Circuit Fault

Cited by 55 publications

References 36 publications

Generalized MIMO Sequence Impedance Modeling and Stability Analysis of MMC-HVDC With Wind Farm Considering Frequency Couplings

Generalized MIMO Sequence Impedance Modeling and Stability Analysis of MMC-HVDC With Wind Farm Considering Frequency Couplings

DC Voltage Control and OLTC Control Strategy for MMC-Based HVDC System Under SM Failure

Thermal Optimization Strategy Based on Second-Order Harmonic Circulating Current Injection for MMCs

Contact Info

Product

Resources

About