基于N-1准则的配电网重构分区评估分析

为解决配电网规划和自动化中的负荷转供问题,结合电网拓扑结构与接线模式,对故障后的配电网重构方案和影响因素进行了分析,提出了配电网重构"N-1"安全准则分区扫描实用评估分析方式,可以对配电网进行完全和逐段两种形式的"N-1"准则校验。同时开发了相应的评估软件,当单馈线无法承担转供负荷时,可以提供多馈线分担转供负荷的方案,并且解决了故障后双电源自动转切负荷对电源馈线容量裕度影响的问题。通过评估软件的分区逐段扫描结果,能够全面、有效地评估配电网的负荷转供能力,并对故障重构的各种方案进行比较。经多个配电网的实际应用,验证了该扫描评估分析方式和软件的效果。

基于GPU加速的大规模系统N-1安全校验中电网连通性的检验方法

随着电力系统规模的扩大,N-1安全校验过程的计算量也显著提升。为了适应N-1安全校验日益上升的实时性需求,提出一种基于图形处理器（graphicsprocessingunit,GPU）加速的大规模系统N-1安全校验中电网连通性的检验方法。根据图论思想,电网模型被抽象为图模型,进而抽象为双向向量图模型。基于向量求和的思想在向量图模型上得到电网连通性判别条件,进行设计连通性检验算法。算例测试表明,所提算法效率高,空间占用小,与传统的连通性检验算法相比具有明显优势,能够有效提高系统N-1安全校验中电网连通性检验的速度,进而有助于大规模电网N-1安全校验整体计算效率的提升,具有工程应用的价值。

含柔性输电装置的输电网规划N-1校核准则研究

输电网规划的重要步骤就是开展比选方案的技术经济校核,其中技术校核的重点又在于规划方案是否满足"N-1"准则。在常规交流电网中,《电力系统安全稳定导则》对需满足"N-1"准则的无件进行了定义:正常运行方式下的电力系统中单一元件,如线路、发电机、变压器等。对于含柔性输电装置的输电网规划方案进行校核时,应充分考虑设备结构以及接入电网的方式等因素,合理确定"N-1"的校核范畴。本文基于柔性输电装置的特性,对其如何与"N-1"准则中"单一元件"的界定进行了研究。通过具体算例的验证,总结得出了含柔性输电装置的输电网规划方案中针对柔性装置的"N-1"校核准则建议。

A Steady-State Contingency Analysis of the SADC Regional Grid Using the N-1 Criterion

Southern Africa has experienced electric power deficits over the last decade. This has been due in part to the member countries＇ inadequate electrical power supply system, as well as load growth in areas which were not adequately planned for. This has induced the formation of organizations such as SADC （Southern African Development Community） and SAPP （Southern African Power Pool） that have the common goal of achieving development and economic growth in the region which comprises of 15 member countries. This paper presents results from a security analysis of the region＇s electric power supply system using a baseline level of performance. This was carried out by performing a steady-state contingency analysis on a SADC power network model subject to the N-1 criteria which expresses the ability of the power network to experience a contingency without causing an overload or failure in any other part of the network. Simulations were carried out using DigSilent.

Transmission network expansion planning with embedded constraints of short circuit currents and N-1 security

An approach of transmission network expan-sion planning with embedded constraints of short circuit currents and N-1 security is proposed in this paper.The problem brought on by the strong nonlinearity property of short circuit currents is solved with a linearization method based on the DC power flow.The model can be converted to a mixed-integer linear programming problem,realizing the optimization of planning model that considers the constraints of linearized short circuit currents and N-1 security.To compensate the error caused by the assump-tions of DC power flow,the compensation factor is pro-posed.With this factor,an iterative algorithm that can compensate the linearization error is then presented.The case study based on the IEEE 118-bus system shows that the proposed model and approach can be utilized to:opti-mize the construction strategy of transmission lines;ensure the N-1 security of the network;and effectively limit the short circuit currents of the system.

1/3码的动态CMOS全自检电路的设计

自检测电路设计方法有多种多样,本文中介绍了TSC电路的概念,并采用1/3码的动态CMOS设计TSC电路,通过在Cadence环境下仿真,仿真结果表明本设计可行。

湘潭二期1×600MW机组降压送出系统研究

为符合国家节能减排政策,降低系统网损,并缓解云田500kV变下网压力,湘潭二期1×600MW机组降压送出工程将在2012年实施。研究表明,湘潭二期1×600MW机组通过1回220kV大截面导线接入白马垄220kV变电站是适宜的。

电力市场环境下区域和省级电网协同安全校核及校正

省内电力市场无法获得外网出清或出力计划,不能保证联络线各支路未来潮流的准确性,尤其是无法有效考虑需省间互济的大功率缺失N-1校核,因此需要进行区域电网的安全校核和校正。为此,考虑基态潮流、未功率缺失N-1故障和功率缺失N-1故障的3种场景约束,建立考虑省级电力现货市场的区域电网安全校正模型;在模型中,考虑省级市场出清特点,提出机组调整价值分析方法;采用奔德斯(Benders)分解方法形成了功率缺失N-1场景子问题,提高计算效率;基于此模型,获得满足安全约束要求的机组组合和越限调整信息,设计分省关键安全约束集,各省基于调整后的机组组合和关键安全约束集重新出清,由此实现区域全网运行安全。以2×IEEE39节点联合算例对所提方法进行验证。

基于图计算的配电网最大供电能力评估研究

最大供电能力是配电网发展的重要参考指标,然而配电网拓扑结构复杂多变使得完整描述供电路径存在一定的局限性。图在描述事物复杂连接关系时具有天然的优势,基于此,开展了基于图计算的配电网最大供电能力评估研究。首先,利用图数据结构与配电网拓扑的一致性,建立了配电网图模型,并利用图遍历描述转供关系,打破了配电网拓扑与描述方法间的壁垒。其次,考虑实际配电网运行约束限制,从转移站内负荷和承担站外转移负荷2个角度,构建了基于图计算的配电网最大供电能力评估模型。最后,利用改进人工鱼群算法求解评估模型,并对结果进行负载修正,获得了满足N-1安全校验的配电网最大供电能力。算例表明,所提出的方法可以有效评估配电网最大供电能力,能够适应配电网拓扑的复杂变化,具有一定的实际应用价值。

考虑多次转供的配电网最大供电能力评估方法

最大供电能力是配电网发展规划的重要参考数据,现有评估方法未考虑多次转供,评估结果偏于保守,不能适应配电网自动化发展趋势。鉴于此,提出一种考虑多次转供的配电网最大供电能力评估模型。首先基于路径描述方式,建立负荷的供电路径集。然后以路径的通断状态为变量,以系统负荷之和最大为目标函数,以配电网N-1安全校验准则为约束条件,建立了配电网最大供电能力评估模型。最后采用粒子群算法求解该问题,并设计了粒子N-1校验不通过时的罚函数。算例证明,该方法可以充分挖掘配电网的供电潜力,同时可以针对各类主变故障提出相应的失电负荷转供策略,破解了传统评估方法的局限性。

差错概率最小化机场安检员在岗模式问题研究

随着国内外安全形势不断严峻,机场安检作为民航安全的重要屏障面临着巨大的压力。安检人员疲劳程度是影响安检差错的主要因素之一。在不改变现有上班模式下,已知不同时段的客流特征、安检员连续在岗时间和安检正确率的关系,建立双目标非线性0~1规划模型,合理安排不同时段内安检人员数量及其连续在岗工作时间模式,使得在安检错误放行概率不高于一定标准的条件下保证安检错误报警概率最小及人员总数最小。文章最后根据模型特点设计了算法并给出了算例。

考虑风电接入和负荷转供的配电网可靠性成本

为了研究风电接入和负荷的一次转供对输配电成本中的可靠性成本的影响,基于配电网的“N-1”安全校验、配电系统安全域和最大供电能力,建立基于主变压器互联的最大供电能力模型;并考虑停电损失费用现值和未来投资成本现值,建立配电网扩容规划模型;根据Beta分布确定风电机组的出力,得出风力发电机组的最佳投资运行时间。在此基础上,根据配电网总额定容量与最大供电能力求出配电网为了保证供电安全稳定而付出的可靠性成本。结果表明,在接入风电机组后,配电网的最大供电能力得以增加,而配电网为了保证供电的安全可靠所需要的成本也相应地减少。

Distribution management system framework based on security region for future low carbon distribution systems

In this paper,a new Distribution Management System(DMS)framework based on security region is proposed.First,the concept of Distribution System Security Region(DSSR)is introduced.DSSR is capable to describe the N-1 security boundary of the whole distribution network,including the secure output range of DGs.This new theoretic tool provides a chance for the implementation of real-time security analysis and active controls in DMS.Second,this paper proposes and describes five security states for distribution system.Third,an upgraded DMS enhanced with DSSR is proposed,which consists of advanced security functions such as preventive and predictive control of the trajectory of operating points.Finally,a practical case is presented to simulate the proposed DSSR-enhanced DMS,in which both the security region of network and the output range of DGs are calculated.Typical security functions are also demonstrated.In conclusion,the new DMS framework aims to help operate the system closed to its security boundary in order to improve the efficiency significantly within same security standard.This work is beneficial for future low carbon distribution systems with high penetration rate of DGs.

Total Quadrant Security Region for Active Distribution Network with High Penetration of Distributed Generation

The region-based method has been applied in transmission systems and traditional passive distribution systems without power sources. This paper proposes the model of total quadrant security region(TQSR) for active distribution networks(ADN) with high penetration of distributed generation(DG). Firstly, TQSR is defined as a closed set of all the N-1 secure operation points in the state space of ADN. Then, the TQSR is modeled considering the constraints of state space,normal operation and N-1 security criterion. Then, the characteristics of TQSR are observed and analyzed on the test systems with different DG penetrations. TQSR can be located in any quadrant of the state space. For different DG penetrations,the shape and security features of TQSR are also different. Finally, the region map is discovered, which summarizes the features of different types of distribution networks.

主动配电网可靠性规划

经济性和可靠性是考量主动配电网规划的两大重要指标,但二者又相对矛盾。基于广义Benders分解算法,建立了以年均综合费用最少为目标的上层规划问题和以年均缺供电费用最小为目标的下层可靠性问题,迭代获得主动配电网可靠性规划方案,实现网架规划、分布式电源规划和可靠性校验的统一求解。结合54节点系统验证所提模型和算法能快速收敛于最优方案。

Reconfiguration in the Transmission System of the Slovak Republic

Topology changes （reconfigurations） in the transmission system are effective remedial actions to restore fulfilling N-I security principle. In the transmission system, Slovak Republic prepares several scenarios of possible reconfigurations, especially in the substation Varin and substation Lemesany. The paper describes reasons of reconfiguration necessity, preparation process, testing process, test results and comparison with expected results from simulation calculations. The conclusion summarizes advantages and disadvantages of the reconfiguration implementation in the transmission system, recommendations for real-time operation, including coordination with neighbouring transmission system operators and affected distribution system operators.

Dynamic-decision-based Real-time Dispatch for Reducing Constraint Violations

This paper proposes a dynamic-decision-based realtime dispatch method to coordinate the economic objective with multiple types of security dispatch objectives while reducing constraint violations in the process of adjusting the system operation point to the optimum.In each decision moment,the following tasks are executed in turn:①locally linearizing the system model at the current operation point with the online model identification by using measurements;②narrowing down the gaps between unsatisfied security requirements and their security thresholds in order of priority;③minimizing the generation cost;④minimizing the security indicators within their security thresholds.Compared with the existing real-time dispatch strategies,the proposed method can adjust the deviations caused by unpredictable power flow fluctuations,avoid dispatch bias caused by model parameter errors,and reduce the constraint violations in the dispatch decision process.The effectiveness of the proposed method is verified with the IEEE 39-bus system.

Exploiting Flexibility of Integrated Demand Response to Alleviate Power Flow Violation During Line Tripping Contingency

Multi-energy integrations provide great opportunities for economic and efficient resource utilization. In the meantime, power system operation requires enough flexible resources to deal with contingencies such as transmission line tripping. Besides economic benefits, this paper focuses on the security benefits that can be provided by multi-energy integrations. This paper first proposes an operation scheme to coordinate multiple energy production and local system consumption considering transmission networks. The integrated flexibility model, constructed by the feasible region of integrated demand response(IDR), is then formulated to aggregate and describe local flexibility. Combined with system security constraints, a multi-energy system operation model is formulated to schedule multiple energy production, transmission, and consumption. The effects of local system flexibility on alleviating power flow violations during N-1 line tripping contingencies are then analyzed through a multi-energy system case. The results show that local system flexibility can not only reduce the system operation costs, but also reduce the probability of power flow congestion or violations by approximately 68.8% during N-1 line tripping contingencies.

基于Infomap算法的配电网边缘划分方法

在能源互联网时代,配电网面临着海量分布式数据的计算和存储需求,而边缘计算可以利用网络末端资源就近提供配用电分析和计算,从而减轻主站计算、存储压力。为了充分发挥配电网边缘计算的优势以及提高配电网精细化运行管理水平,文章提出了一种基于Infomap算法的配电网边缘划分方法。首先,考虑配电网边缘规模和自治需求,明确定义配电网边缘范围并设计边缘划分原则;然后,构建基于路径描述的配电网N-1安全校验模型,并用求解出的联络开关动作次数量化边缘间联系的紧密程度;最后,基于复杂网络社区检测的思想,将配电网抽象为图模型,并结合Infomap算法和配电网运行管理特点进行边缘划分,通过实际配电网的算例验证了文中方法的有效性与合理性。

A diagnostic method for distribution networks based on power supply safety standards

In order to overcome the shortages of diagnostic method for distribution networks considering the reliability assessment,this paper proposed a method based on power supply safety standards.It profoundly analyzed the security standard of supply for urban power networks,and established quantitative indicators of load groups based on different fault conditions.Then a method suitable for diagnostic evaluation of urban distribution networks in China was given.In the method,“N-1”calibration analysis of the distribution network was conducted.Then the results are compared with quantitative indicators of load groups on different conditions deriving the diagnostic conclusions and the standard revision is discussed.The feasibility and accuracy of the method is finally verified in the case study.