频率紧急控制中动作时延和措施量对低惯量系统控制有效性的影响分析

doi:10.19595/j.cnki.1000-6753.tces.231175

Abstract
Figure/Table
References (0)
Related Citation (15)

Download: PDF (984 KB) HTML (1 KB)
Export: BibTeX | EndNote (RIS)

Abstract

Frequency emergency control (FEC) is the second defense line to ensure frequency safety after power grid failures, usually triggered by event of fault, and has become a standard configuration of Ultra-High Voltage DC (UHVDC). With the rapid development of high proportion of new energy (NE), the frequency regulation ability and system inertia are continuously decreasing. The frequency response characteristics after power grid faults have some new characteristics of large drop depth and fast speed. The effectiveness of emergency control is a key factor related to the frequency safety.
This article first establishes frequency response model and transfer function of a high proportion NE power system considering FEC.To analyze the effectiveness of emergency control, this article focuses on two types of disturbances: permanent power disturbances (PPD) and short-term power disturbances (STPD). PPD are represented by faults such as DC blocking, unit tripping, and NE disconnection; STPD are represented by low voltage ride through (LVRT, without disconnection) of NE or flexible DC, DC commutation failure.
According to the derivation, the time-domain expression of the system frequency response considering FEC under PPD can be obtained. FEC may not always solve the transient frequency insecurity risk depending on whether the system deviation reaches the control threshold of under-frequency load shedding (UFLS) or over-frequency generator tripping (OFGT) after FEC. When FEC action delay τ₀ is less the time when the frequency reaches its lowest point t_m, the maximum frequency deviation will be improved. But excessive emergency control amount can cause the risk of transient high-frequency in the system. When the delay of FEC is greater than the moment when the system's minimum frequency occurs, FEC cannot improve the maximum frequency deviation. For the current technical level, the emergency control delay is considered as 300ms.If a PPD of 30% load capacity occurs, the limit value for NE access is 65% of the load.
Under STPD the steady-state frequency deviation is zero. With the continuous increase of NE, DC and other power electronic power sources, the amount of STPD will continue to increase. In severe cases, it can also cause the system's transient frequency to cross unsafe boundaries, which may lead to the current frequency corrective control line action and lead to power outages. As the proportion of synchronous machines decreases, the released kinetic energy decreases due to the rotational inertia. So that under the same STPD, the lowest frequency of the system gradually decreases to the threshold value of the third defense such as UFLS, and the demand for FEC is becoming increasingly high. Although timely FEC can improve the minimum frequency and avoid triggering UFLS, excessive FEC may lead to risks of OFGT. As the proportion of synchronous machines gradually decreases, the range of reasonable amounts of FEC that can be taken gradually decreases. When the proportion of synchronous machines is less than 34% of load, under a given STPD boundary, FEC cannot solely rely on traditional one-time actions to avoid triggering UFLS and OFGT.
The following conclusions can be drawn:
(1) The large-scale replacement of traditional synchronous power sources with NE has led to a decrease in the inertia and frequency regulation ability of the power grid, and the increased ROCOF is an important reason for affecting the adaptability of FEC.
(2)In a high proportion of NE grids, large-scale LVRT of NE and flexible DC, conventional DC commutation failure caused by AC short circuit faults can generate significant STPD. Compared to traditional DC blocking faults, it may cause system frequency "flicker" and easily trigger UFLS. When responding to FEC, it is necessary to not only meet the low-frequency control requirements, but also avoid interlocking high-frequency after control implementation, which becomes more and more difficult to adapt to.
STPD such as large-scale LVRT of NE pose significant challenges to the frequency security defense system. Further research is needed on how to improve the grid performance of NE, build grid inertia capacity, optimize FEC and corrective control strategies based on the actual needs of the power grid.

Key words： New energy frequency safety frequency emergency control low inertia power system short term power disturbance low voltage ride through of new energy

Received: 23 July 2023

PACS:

TM76

	Service

	E-mail this article
	Add to my bookshelf
	Add to citation manager
	E-mail Alert
	RSS
	Articles by authors
	Li Zhaowei
	Fang Yongjie
	Wu Xuelian
	Li Jianhua
	Lai Yening

Cite this article:

Li Zhaowei,Fang Yongjie,Wu Xuelian等. Influence of Action Delay and Amount on the Control Effectiveness of Low Inertia Systems in Frequency Emergency Control[J]. Transactions of China Electrotechnical Society, 0, (): 231175-.

URL:

https://dgjsxb.ces-transaction.com/EN/10.19595/j.cnki.1000-6753.tces.231175 OR https://dgjsxb.ces-transaction.com/EN/Y0/V/I/231175

[1] 方勇杰. 英国“8·9”停电事故对频率稳定控制技术的启示[J]. 电力系统自动化, 2019, 43(24): 1-5.
Fang Yongjie.Reflections on frequency stability control technology based on the blackout event of 9 August 2019 in UK[J]. Automation of Electric Power Systems, 2019, 43(24): 1-5.
[2] 孙华东, 许涛, 郭强, 等. 英国“8·9”大停电事故分析及对中国电网的启示[J]. 中国电机工程学报, 2019, 39(21): 6183-6192.
Sun Huadong, Xu Tao, Guo Qiang, et al.Analysis on blackout in great Britain power grid on August 9th, 2019 and its enlightenment to power grid in China[J]. Proceedings of the CSEE, 2019, 39(21): 6183-6192.
[3] 曾辉, 孙峰, 李铁, 等. 澳大利亚“9·28”大停电事故分析及对中国启示[J]. 电力系统自动化, 2017, 41(13): 1-6.
Zeng Hui, Sun Feng, Li Tie, et al.Analysis of “9·28” blackout in South Australia and its enlightenment to China[J]. Automation of Electric Power Systems, 2017, 41(13): 1-6.
[4] 李兆伟, 吴雪莲, 庄侃沁, 等. “9·19”锦苏直流双极闭锁事故华东电网频率特性分析及思考[J]. 电力系统自动化, 2017, 41(7): 149-155.
Li Zhaowei, Wu Xuelian, Zhuang Kanqin, et al.Analysis and reflection on frequency characteristics of East China grid after bipolar locking of “9·19” jinping-sunan DC transmission line[J]. Automation of Electric Power Systems, 2017, 41(7): 149-155.
[5] 刘洋, 王聪颖, 夏德明, 等. 电网故障导致大面积风电低电压穿越对电网频率的影响分析及措施[J]. 电网技术, 2021, 45(9): 3505-3514.
Liu Yang, Wang Congying, Xia Deming, et al.Influence of large area wind power low voltage ride-through on power grid frequency caused by power grid faults[J]. Power System Technology, 2021, 45(9): 3505-3514.
[6] 花赟玥, 吴琛, 黄伟, 等. 考虑风电低电压穿越过程的频率最低点量化及其提升方法[J]. 电力系统自动化, 2023, 47(1): 126-134.
Hua Yunyue, Wu Chen, Huang Wei, et al.Quantification and enhancement method for frequency nadir considering low voltage ride-through process of wind power[J]. Automation of Electric Power Systems, 2023, 47(1): 126-134.
[7] 国家能源局. 电力系统网源协调技术规范: DL/T 1870—2018[S]. 北京: 中国电力出版社, 2018.
[8] 国家质量监督检验检疫总局, 中国国家标准化管理委员会. 电力系统安全稳定控制技术导则: GB/T 26399-2011 [S]. 北京: 中国标准出版社, 2011.
[9] 文云峰, 杨伟峰, 林晓煌. 低惯量电力系统频率稳定分析与控制研究综述及展望[J]. 电力自动化设备, 2020, 40(9): 211-222.
Wen Yunfeng, Yang Weifeng, Lin Xiaohuang.Review and prospect of frequency stability analysis and control of low-inertia power systems[J]. Electric Power Automation Equipment, 2020, 40(9): 211-222.
[10] 张冠锋, 杨俊友, 王海鑫, 等. 基于虚拟同步机技术的风储系统协调调频控制策略[J]. 电工技术学报, 2022, 37(增刊1): 83-92.
Zhang Guanfeng, Yang Junyou, Wang Haixin, et al.Coordinated frequency modulation control strategy of wind farm-storage system based on virtual synchronous generator technology[J]. Transactions of China Electrotechnical Society, 2022, 37(S1): 83-92.
[11] 张剑云, 李明节. 新能源高渗透的电力系统频率特性分析[J]. 中国电机工程学报, 2020, 40(11): 3498-3506, 中插11.
Zhang Jianyun, Li Mingjie. Analysis of frequency characteristics of power system with high permeability of new energy[J]. Proceedings of the CSEE, 2020, 40(11): 3498-3506, 中插11.
[12] 闵勇, 陈磊, 刘瑞阔, 等. 电力系统频率动态中惯量与惯量响应特性辨析[J]. 中国电机工程学报, 2023, 43(3): 853-867, 中插1.
Min Yong, Chen Lei, Liu Ruikuo, et al. Analysis on characteristics of inertia and inertial response in power system frequency dynamics[J]. Proceedings of the CSEE, 2023, 43(3): 853-867, 中插1.
[13] 王科, 秦文萍, 张宇, 等. 双馈风机等效惯量控制比例系数对系统功角首摆稳定的影响机理分析[J]. 电工技术学报, 2023, 38(3): 741-753.
Wang Ke, Qin Wenping, Zhang Yu, et al.Mechanism analysis of effect of equivalent proportional coefficient of inertia control of DFIG on stability of first swing of power angle[J]. Transactions of China Electrotechnical Society, 2023, 38(3): 741-753.
[14] 陈国平, 李明节, 许涛. 特高压交直流电网系统保护及其关键技术[J]. 电力系统自动化, 2018, 42(22): 2-10.
Chen Guoping, Li Mingjie, Xu Tao.System protection and its key technologies of UHV AC and DC power grid[J]. Automation of Electric Power Systems, 2018, 42(22): 2-10.
[15] 罗亚洲, 陈得治, 李轶群, 等. 华北多特高压交直流强耦合大受端电网系统保护方案设计[J]. 电力系统自动化, 2018, 42(22): 11-18, 68.
Luo Yazhou, Chen Dezhi, Li Yiqun, et al.Design of system protection scheme for North China multi-UHV AC and DC strong coupling large receiving-end power grid[J]. Automation of Electric Power Systems, 2018, 42(22): 11-18, 68.
[16] 柯德平, 冯帅帅, 刘福锁, 等. 新能源发电调控参与的送端电网直流闭锁紧急频率控制策略快速优化[J]. 电工技术学报, 2022, 37(5): 1204-1218.
Ke Deping, Feng Shuaishuai, Liu Fusuo, et al.Rapid optimization for emergent frequency control strategy with the power regulation of renewable energy during the loss of DC connection[J]. Transactions of China Electrotechnical Society, 2022, 37(5): 1204-1218.
[17] 孙诚斌, 李兆伟, 李碧君, 等. 电化学储能参与电网低频第三道防线的控制策略[J]. 电力工程技术, 2021, 40(3): 27-34.
Sun Chengbin, Li Zhaowei, Li Bijun, et al.A control strategy for the low frequency third defense line of power grid containing the electrochemical energy storage[J]. Electric Power Engineering Technology, 2021, 40(3): 27-34.
[18] 李兆伟, 方勇杰, 李威, 等. 电化学储能应用于电网频率安全防御三道防线的探讨[J]. 电力系统自动化, 2020, 44(8): 1-7.
Li Zhaowei, Fang Yongjie, Li Wei, et al.Discussion on application of electrochemical energy storage in three defense lines of power grid frequency[J]. Automation of Electric Power Systems, 2020, 44(8): 1-7.
[19] 许涛, 吴雪莲, 李兆伟, 等. 改善系统频率稳定性的多直流功率紧急支援协调控制策略[J]. 电力系统自动化, 2018, 42(22): 69-77, 143.
Xu Tao, Wu Xuelian, Li Zhaowei, et al.Coordinated control strategy of multi-DC emergency power support to improve frequency stability of power systems[J]. Automation of Electric Power Systems, 2018, 42(22): 69-77, 143.
[20] 李兆伟, 方勇杰, 黄慧, 等. 系统保护中跨区直流频率调制与紧急功率支援的协调控制[J]. 电力系统自动化, 2020, 44(22): 31-36.
Li Zhaowei, Fang Yongjie, Huang Hui, et al.Coordinated control of cross-region DC frequency control and emergency power support in system protection[J]. Automation of Electric Power Systems, 2020, 44(22): 31-36.
[21] 电力安全事故应急处置和调查处理条例[S]电力安全事故应急处置和调查处理条例[S].北京:中国电力出版社,2011.
[22] Kundur P, Balu N J, Lauby M G.Power system stability and control[M]. New York: McGraw-Hill, 1994.
[23] 李明节. 大规模特高压交直流混联电网特性分析与运行控制[J]. 电网技术, 2016, 40(4): 985-991.
Li Mingjie.Characteristic analysis and operational control of large-scale hybrid UHV AC/DC power grids[J]. Power System Technology, 2016, 40(4): 985-991.
[24] 赵畹君. 高压直流输电工程技术[M]. 2版. 北京: 中国电力出版社, 2011.
[25] 李德胜, 罗剑波. 特高压直流配套安全稳定控制系统的典型设计[J]. 电力系统自动化, 2016, 40(14): 151-157.
Li Desheng, Luo Jianbo.Typical design of security and stability control system for UHVDC transmission[J]. Automation of Electric Power Systems, 2016, 40(14): 151-157.
[26] 许涛, 励刚, 于钊, 等. 多直流馈入受端电网频率紧急协调控制系统设计与应用[J]. 电力系统自动化, 2017, 41(8): 98-104.
Xu Tao, Li Gang, Yu Zhao, et al.Design and application of emergency coordination control system for multi-infeed HVDC receiving-end system coping with frequency stability problem[J]. Automation of Electric Power Systems, 2017, 41(8): 98-104.