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Abstract

In the asynchronous interconnected power grid that is composed of the multiterminal voltage-source converter high voltage direct current (VSC-MTDC) system, the control methods of each converter station and the frequency of the connected AC system are not the same. When a fault occurs in any place of the asynchronous interconnected system, it will cause the system to have power shortage or surplus, affecting the safe and stable operation of the interconnected power grid. In order to solve the problem of insufficient regional active power reserve, based on the VSC-MTDC asynchronous regional interconnection system and the principle of regional sharing, the dynamic power controller under disturbance conditions is established, and the controller parameters are set to achieve the accuracy of unbalanced power in the disturbance area measuring. Then, according to the degree of the disturbance power, considering the factors that affect the support effect of the converter station, an emergency DC power support (EDCPS) scheme under different power disturbances is formulated to achieve power compensation for the disturbance area. Based on PSCAD/EMTDC software, the proposed control strategy is simulated. The result shows that the converter station closer to the disturbance area has a better support effect, and the dynamic active power controller can timely and accurately deliver to the disturbance area when the active power reserve is insufficient.
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Bibliography

[1] Li X., Zeng Q.,Wang Y., Zhang Y., Control strategies of voltage source converter based direct current transmission system, Gaodianya Jishu/High Voltage Engineering, vol. 42, no. 10, pp. 3025–3037 (2016).
[2] Kontos E., Tsolaridis G., Teodorescu R., Bauer P., Full-bridge MMC DC fault ride-through and STATCOM operation in multi-terminal HVDC grids , Bulletin of the Polish Academy of Sciences: Technical Sciences, vol. 65, no. 5, pp. 653–662 (2017).
[3] Huang R., Zhu Z., Chen J., Chen M., Zou C., Xu S., Research and Experimental Validation of Control and Protection Strategy of HVDC Circuit Breaker in Fault Condition Application in Nan’ao Multi- Terminal VSC-HVDC System, Dianwang Jishu/Power System Technology, vol. 42, no. 7, pp. 2339–2345 (2018).
[4] Guo X., Zhou Y., Mei N., Zhao B., Construction and Characteristic Analysis of Zhangbei Flexible DC Grid, Dianwang Jishu/Power System Technology, vol. 42, no. 11, pp. 3698–3707 (2018).
[5] Xu T. et al., Design and Application of Emergency Coordination Control System for Multi-infeedHVDC Receiving-end System Coping with Frequency Stability Problem, Dianli Xitong Zidonghua/Automation of Electric Power Systems, vol. 41, no. 8, pp. 98–104 (2017).
[6] Lin Q., Li X., Hu N., Wang X., Li K., A multi-agent based emergency DC power support strategy, Dianwang Jishu/Power System Technology, vol. 38, no. 5, pp. 1150–1155 (2014).
[7] Yu T., Shen D., Ren Z., Research on emergency power shifting control of multi-circuit HVDC systems from Central China Power Grid to East China Power Grid, Power System Technology, vol. 28, no. 12, pp. 1–4+19 (2004).
[8] Yang W., Xue Y., Jing Y., Chao J., Huang W., Hong C., Yang B., Emergency DC power support to AC power system in the south china power grid, Dianli Xitong Zidonghua/Automation of Electric Power Systems, vol. 27, no. 17, pp. 68–72 (2003).
[9] Weng H., Xu Z., Xu F., Tu Q., Dong H., Research on constraint factor of emergency power support of HVDC systems, Zhongguo Dianji Gongcheng Xuebao/Proceedings of the Chinese Society of Electrical Engineering, vol. 34, no. 10, pp. 1519–1527 (2014).
[10] Li G., Fu G., Wang S., Li J., Emergency power support control for MMC flexible HVDC transmission system during AC fault, Power System Protection and Control, vol. 46, no. 13, pp. 107–112 (2018).
[11] Li Cong, Li Y., Guo J., He P., Research on emergency DC power support coordinated control for hybrid multi-infeed HVDC system, Archives of Electrical Engineering, vol. 69, no. 1, pp. 5–12 (2020).
[12] Zhu R., Li X., Ying D., A frequency stability control strategy for interconnected VSC-MTDC transmission system, Dianwang Jishu/Power System Technology, vol. 38, no. 10, pp. 2729–2734 (2014).
[13] Zhang W., Fang X., The Support for Regional Grid Catastrophe Recovery from Multi-terminal DC Asynchronous Interconnection, Power System and Automation, vol. 39, no. 1, pp. 66–69 (2017).
[14] XuT. et al., Coordinated Control Strategy of Multi-DC Emergency Power Support to Improve Frequency Stability of Power Systems, Dianli Xitong Zidonghua/Automation of Electric Power Systems, vol. 42, no. 22, pp. 69–77+143 (2018).
[15] Rakibuzzaman S., Robin P., Mike B., The Impact of Voltage Regulation of Multiinfeed VSC-HVDC on Power System Stability, IEEE Transactions on Energy Conversion, vol. 33, no. 4, pp. 1614-1627 (2018).
[16] Nadew A.B., Cornelis A.P., Analysis of Faults in Multiterminal HVDC Grid for Definition of Test Requirements of HVDC Circuit Breakers, IEEE Transactions on Power Delivery, vol. 33, no. 1, pp. 403–411 (2018).
[17] Fuchs A., Imhof M., Demiray T., Morari M., Stabilization of large power systems using vsc-hvdc and model predictive control, IEEE Transactions on Power Delivery, vol. 29, no. 1, pp. 480–488 (2014).
[18] Harnefors L., Johansson N., Zhang L., Berggren B., Interarea oscillation damping using active-power modulation of multiterminal HVDC transmissions, IEEE Transactions on Power Systems, vol. 29, no. 5, pp. 2529–2538 (2014).
19] Tang G., He Z., Pang H., Research, application and development of VSC-HVDC engineering technology, Dianli Xitong Zidonghua/Automation of Electric Power Systems, vol. 37, no. 15, pp. 3–14 (2013).
[20] Naushath M., Athula D., Aniruddha M., Ioni T., Investigation of Fault Ride-Through Capability of Hybrid VSC-LCC Multi-Terminal HVDC Transmission Systems, IEEE Transactions on Power Delivery, vol. 34, no. 1, pp. 241–250 (2019).
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Authors and Affiliations

Congshan Li
1
ORCID: ORCID
Tingyu Sheng
1
ORCID: ORCID
Yan Fang
1
ORCID: ORCID
Yikai Li
1
ORCID: ORCID

  1. School of Electrical and Information Engineering, Zhengzhou University of Light Industry, China
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Abstract

The use of computer techniques at the design stage of industrial facilities is essential in modern times. The ability to shorten the time required to develop a project and assess the safety of the use of assumptions, often enables the reduction of the costs incurred in the future. The possibility to skip expensive prototype tests by using 3D prototyping is why it is currently the prevailing model in the design of industrial facilities, including in the mining industry. In the case of a longwall working, its stability requires the maintenance of the geometric continuity of floor rocks in cooperation with a powered roof support.

The paper investigates the problem of longwall working stability under the influence of roof properties, coal properties, shield loading and the roof-floor interaction. The longwall working stability is represented by an index, factor of safety (FOS), and is correlated with a previously proposed roof capacity index ‘g‘. The topic of the paper does address an issue of potential interest.

The assessment of the stability of the roof in longwalls was based on the numerical analysis of the factor of safety (FOS), using the Mohr-Coulomb stress criterion. The Mohr-Coulomb stress criterion enables the prediction of the occurrence of failures when the connection of the maximum tensile principal stress σ1 and the minimum compressive principal stress σ3 exceed relevant stress limits. The criterion is used for materials which indicates distinct tensile and compressive characteristics. The numerical method presented in the paper can be utilized in evaluating the mining natural hazards through predicting the parameters, which determine the roof maintenance in the longwall working.

One of the purposes of the numerical analysis was to draw attention to the possibilities that are currently created by specialized software as an important element accompanying the modern design process, which forms part of intelligent underground mining 4.0.

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Authors and Affiliations

Tomasz Janoszek
ORCID: ORCID
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Abstract

Tremors occur randomly in terms of time, energy as well as the location of their focus. The present state of knowledge and technology does not allow for the precise prediction of these values. Therefore, it is extremely important to correctly select a powered roof support for specific geological and mining conditions, especially in the case of areas where dynamic phenomena are often registered. This article presents information on rock burst hazard associated with the occurrence of rock mass tremors and their influence on a powered roof support. Furthermore, protection methods of a powered roof support against the negative effects of dynamic phenomena are discussed. As a result of an analysis the methodology, to determine the impact of dynamic phenomena on the powered roof support in given geological and mining conditions is presented.

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Authors and Affiliations

Wojciech Masny
ORCID: ORCID
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Abstract

Voltage source converter-based multi-terminal high-voltage direct current (VSCMTDC) transmission system can realize a multi-point power supply, multi-drop power receiving, and mutual coordination between the converter stations to ensure the reliability of the transmission. Based on the PSCAD/EMTDC platform, a five-terminal DC transmission system model is established. According to the fast power regulation capability and overload capacity of theVSC-MTDC power transmission system, an analysis of additional emergency power support for a transmission system under large disturbance conditions was carried out. A new control strategy for emergency power support that introduces its basic principle is proposed in this paper. It uses the short-term overload capability of the DC system. By changing the power reserve of the converter station and the electrical distance between the converter stations, the influence of the power reserve and the electrical distance on the emergency power supply guarantee is analyzed the stability of the system is improved, thereby improving the sudden change of power caused by voltage fluctuations, and the feasibility of the control module is verified by PSCAD simulation. The simulation results show that when the system power supply suddenly changes, the converter stations at a short distance and large power reserve has a better effect on emergency power supply protection. A comparative study of the active power support of a single converter station and multiple converter stations is carried out. The research results show that the use of emergency power support in the DC transmission system has a good effect on maintaining the stability of the inter-connection system and the reliability of the power supply.
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Authors and Affiliations

Congshan Li
1
ORCID: ORCID
Zikai Zhen
1
ORCID: ORCID
Tingyu Sheng
2
ORCID: ORCID
Yan Liu
1
ORCID: ORCID
Pu Zhong
1
Xiaowei Zhang
1

  1. Zhengzhou University of Light Industry, College of Electrical and Information Engineering, China
  2. Maintenance Company of State Grid Henan Electric Power Company, China

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