WO2023077889A1 - 一种半波长输电系统的暂态稳定快速判定方法及系统 - Google Patents

一种半波长输电系统的暂态稳定快速判定方法及系统 Download PDF

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WO2023077889A1
WO2023077889A1 PCT/CN2022/110130 CN2022110130W WO2023077889A1 WO 2023077889 A1 WO2023077889 A1 WO 2023077889A1 CN 2022110130 W CN2022110130 W CN 2022110130W WO 2023077889 A1 WO2023077889 A1 WO 2023077889A1
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transmission system
wavelength
power transmission
generator
instability
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PCT/CN2022/110130
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English (en)
French (fr)
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�田�浩
杨冬
蒋哲
赵康
马欢
周宁
张志轩
程定一
李山
刘文学
房俏
郝旭东
邢法财
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国网山东省电力公司电力科学研究院
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Publication of WO2023077889A1 publication Critical patent/WO2023077889A1/zh

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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
    • H02H7/06—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for dynamo-electric generators; for synchronous capacitors
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for ac mains or ac distribution networks

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  • the invention relates to the technical field of transient power angle stability analysis of a force system, in particular to a method and system for quickly determining transient stability of a half-wavelength power transmission system.
  • the half-wavelength AC power transmission technology refers to the ultra-long-distance three-phase AC power transmission technology whose electrical distance of power transmission is close to a power frequency half-wave, which is about 3000km at 50Hz.
  • the advantage of the half-wavelength line itself that it does not emit or absorb reactive power makes the transmission system structure simpler, and there is no need to provide additional voltage support equipment along the line; compared with the UHV DC transmission method, The complex commutation process and harmonic pollution are avoided, and the construction and maintenance of equipment are easier. Therefore, half-wavelength power transmission technology has certain research prospects and can play a certain role in the construction of future power grids.
  • the half-wavelength transmission line has the most serious fault area. When a short-circuit fault occurs near this area, it will cause overvoltage along the line and also cause a significant increase in the electromagnetic power of the generator. The imbalance between electromagnetic power and mechanical power increases the transient state of the system. risk of instability.
  • the length of the half-wavelength transmission line is usually slightly longer than the half-wave distance of the power frequency. Under normal operating conditions, the electrical angle between the sending and receiving ends is about 180°.
  • engineering often uses the maximum generator power angle difference greater than a certain limit as the basis for judging whether the system is stable or not. According to different documents, this value is usually in the range of 180° to 360°. Obviously, this engineering practicality criterion is not applicable to the half-wavelength power transmission system whose power angle exceeds 180° under normal operating conditions, and a more general stability determination method needs to be sought.
  • Generator real-time trajectory information directly reflects the degree of transient stability of the power system, and the analysis and control of real-time transient stability based on the measured trajectory information does not depend on models and parameters.
  • the present invention proposes a method and system for quickly determining the transient stability of a half-wavelength power transmission system. Classification.
  • the present invention adopts the following technical solutions:
  • a method for quickly determining transient stability of a half-wavelength power transmission system comprising:
  • the instability modes include two power angle instability modes for constructing a half-wavelength power transmission system based on the equal-area method, that is, instability mode 1 and instability mode 2.
  • the generator continues to decelerate and become unstable, and in the instability mode 2, the generator decelerates first, and then continues to accelerate and become unstable.
  • the constructed index system includes: a generator power angle-angular velocity phase plane curve constructed with the power angle of the generator as the abscissa and the angular velocity of the generator as the ordinate.
  • the constructed index system further includes: a convex region boundary, which is constructed based on the concavity of the phase trajectory defined by the slope of the phase trajectory of the generator power angle-angular velocity phase plane curve as the power angle changes.
  • the generator trajectory moves to the left plane and crosses the boundary of the left convex region as instability mode 1.
  • instability mode 2 that the generator trajectory first moves to the left plane, then moves to the right plane and crosses the boundary of the right convex region.
  • the index system constructed also includes: an auxiliary index characterizing the direction field of the inflection point;
  • the constructed index system is discretized by using the discretization processing method of the constructed judgment index, so as to judge the transient power angle stability and instability mode of the half-wavelength transmission system according to the discretized index system.
  • a fast transient stability determination system for a half-wavelength power transmission system comprising:
  • the data acquisition unit is configured to acquire the power and power angle of the generator at the sending end of the half-wavelength power transmission system
  • the mode determination unit is configured to determine the transient power angle stability and its instability mode of the half-wavelength power transmission system by using the constructed index system;
  • the instability modes include two power angle instability modes for constructing a half-wavelength power transmission system based on the equal-area method, that is, instability mode 1 and instability mode 2.
  • a computer-readable storage medium in which a plurality of instructions are stored, and the instructions are suitable for being loaded by a processor of a terminal device and executing the described method for fast determination of transient stability of a half-wavelength power transmission system.
  • a terminal device including a processor and a computer-readable storage medium, the processor is used to implement instructions; the computer-readable storage medium is used to store multiple instructions, and the instructions are suitable for being loaded by the processor and executing the described one Fast transient stability determination for half-wavelength power transmission systems.
  • the invention constructs two types of instability modes unique to the half-wavelength power transmission system, which can accurately describe the transient power angle characteristics of the half-wavelength power transmission system under severe faults, and its characteristics are significantly different from those of the AC power transmission mode .
  • the invention constructs a transient stability judgment method based on the locus curve of the generator at the sending end of the half-wavelength power transmission system.
  • the trajectory concavity is defined based on the rate of change of the generator trajectory slope with the power angle, and the boundary of the convex region is constructed. According to the direction and angle of the generator trajectory entering the boundary of the convex region, different instability modes are classified, which ensures the accuracy and operability of the transient stability judgment.
  • the invention constructs a discretization processing method for the determination index, and proposes an auxiliary index representing the direction field of the inflection point.
  • a discretization processing method for judgment indicators is constructed.
  • auxiliary indicators representing the direction field of the inflection point the influence of factors such as data errors, excitation regulators, and frequency regulators is avoided, and the judgment of transient stability is more robust.
  • Fig. 1 is the flowchart of the present embodiment
  • Fig. 2 (a) is the phase 1 diagram of the power angle operation state of the half-wavelength power transmission system of the present embodiment
  • Fig. 2 (b) is the phase 2 diagram of the power angle operation state of the half-wavelength power transmission system of the present embodiment
  • Fig. 3 is a phase locus diagram under different fault removal times in the half-wavelength transmission line area of the present embodiment
  • Fig. 4 is a curve diagram of the phase locus of the generator at the sending end under the test conditions of the present embodiment
  • FIG. 5 is a time-domain change diagram of the temporary stability judgment index under the test conditions of this embodiment.
  • a method for quickly determining the transient stability of a half-wavelength power transmission system includes the following steps:
  • instability mode 1 the generator continues to decelerate and become unstable
  • instability mode 2 the generator decelerates first, and then continues to accelerate and become unstable
  • S2 Obtain the power and power angle of the generator at the sending end of the half-wavelength transmission system based on the wide area measurement system (WAMS) and the phasor measurement unit (PMU); the power of the generator includes: mechanical power and electromagnetic power;
  • WAMS wide area measurement system
  • PMU phasor measurement unit
  • S4 Define the concavity of the phase trajectory based on the slope of the phase trajectory of the generator power angle-angular velocity phase plane curve with the change rate of the power angle, and construct the boundary of the convex region;
  • S5 Define the generator trajectory to move to the left plane and cross the boundary of the left convex region, which is considered as instability mode 1 in step 1; define the generator trajectory to move to the left plane first, then move to the right plane and pass through the right side The boundary of the convex region is identified as the instability mode 2 in step 1;
  • S7 Quickly determine the transient power angle stability and instability mode of the half-wavelength power transmission system according to the constructed index system.
  • ⁇ 0 is the synchronous angular velocity in the initial state
  • ⁇ is the change in angular velocity
  • T J is the inertial time constant
  • P m and P e ( ⁇ ) are the mechanical power and electromagnetic power, respectively
  • ⁇ is the power angle of the generator
  • t is time.
  • Fig. 2 shows the relationship curve between the electromagnetic power of the generator and the power angle under fault conditions, where the angles shown in Fig. 2(a) and Fig. 2(b) represent the power angle of the generator.
  • Figure 2(a) when a fault occurs in the most serious fault area of the half-wavelength line, the electromagnetic power will be significantly higher than the mechanical power, and the operating point of the system will move from point a to point b, and the power angle of the generator will show a decreasing trend , to obtain the deceleration area A-.
  • the power angle will oscillate between points g and e, and if the damping effect is considered, the angle will eventually return to the initial operating point ⁇ 0 . From the above analysis, it can be found that there are two power angle instability modes near the most serious fault point of the half-wavelength transmission line. First, in the operation stage 1, if the acceleration area A+ ⁇ A- is obtained when the power angle of the generator reaches ⁇ min , the generator will continue to obtain the deceleration area, and the angular velocity will continue to decrease until it stops.
  • S2 Obtain the electromagnetic power and power angle of the generator at the sending end of the half-wavelength transmission system based on the wide area measurement system (WAMS) and the phasor measurement unit (PMU);
  • WAMS wide area measurement system
  • PMU phasor measurement unit
  • the wide area measurement system (WAMS) and the phasor measurement unit (PMU) have been widely used in the field of power grid state monitoring.
  • the present invention uses the real-time data of the power grid collected by the system and the device as input.
  • the power angle-angular velocity ( ⁇ - ⁇ ) phase plane of the system can be constructed, and the transient process of the generator can be expressed as a curve that changes with time on the phase plane, called the phase plane. track.
  • the stability of the system can be analyzed according to the phase trajectory. When a three-phase short circuit occurs at the most serious fault point of a half-wavelength transmission line, the moment the fault occurs, the electromagnetic power rises instantaneously, showing a negative unbalanced power, and the angular velocity shows a decreasing trend. The power angle continues to decrease. If the fault can be removed in time, a closed phase trajectory will appear and the system will be stable. If the fault cannot be removed in time, the trajectory of the generator will diverge and become unstable.
  • S4 Define the concavity of the phase trajectory based on the slope of the phase trajectory of the generator power angle-angular velocity phase plane curve with the change rate of the power angle, and construct the boundary of the convex region;
  • the slope of the phase locus of the generator at the sending end of the half-wavelength transmission system is derived as:
  • ⁇ is the power angle of the generator
  • ⁇ 0 is the synchronous angular velocity in the initial state
  • ⁇ is the angular velocity variation
  • M is the inertia constant
  • ⁇ P( ⁇ ) is the electromagnetic power variation.
  • the rate of change of the slope of the phase trajectory with the change of the power angle is derived as:
  • the boundary derivation of the convex region is further as follows:
  • ⁇ P'( ⁇ ) is the first derivative of the unbalanced power with respect to the power angle.
  • the phase trajectory and concave-convex boundary of the generator drawn on the phase plane are shown in Figure 3.
  • the fast fault clearing time can make the trajectory appear an inflection point, so that a clockwise closed trajectory appears, and the system remains stable; If the fault is cleared internally, the power angle will continue to accelerate or decelerate along the original running trend, resulting in system instability.
  • the power angle difference between sending and receiving ends of the half-wavelength line has exceeded 180° during normal operation, it can be found by observing the phase trajectory curve that the instability of the system is not directly related to the absolute size of the power angle difference.
  • the combined effect of fault clearing time, load level and generator dynamic characteristics Therefore, the analysis of the phase trajectory characteristics after the fault occurs can be used to judge the transient stability of the half-wavelength transmission system, avoiding the misjudgment that may be caused by the absolute value judgment method of the power angle difference.
  • S5 Define the phase trajectory of the generator to move to the left plane and cross the boundary of the left convex region, which is identified as instability mode 1 in step 1; define the phase trajectory of the generator to move to the left plane first, then move to the right plane and Crossing the boundary of the right convex region is identified as instability mode 2 in step 1;
  • phase trajectory of the generator when the fault removal time is t1, the phase trajectory of the generator is a closed curve, and the system is considered stable; when the fault removal time is t3, the phase trajectory of the generator moves to the left plane and passes through the left convex area Boundary, identified as system instability, and defined as instability mode 1; when the fault removal time is t2, the generator trajectory first moves to the left plane, then moves to the right plane and crosses the boundary of the right convex area, and is identified as system failure stable, and defined as instability mode 2.
  • the above stability judgment formula is given based on the model. In order to adapt to the response-based stability judgment, it is necessary to discretize the judgment index.
  • the judgment index after discretization is:
  • auxiliary index r that characterizes the direction field of the inflection point is proposed.
  • the auxiliary index r is now defined as:
  • the discretized engineering auxiliary judgment index is:
  • ⁇ P'(i) is the first derivative of electromagnetic power variation.
  • S7 Quickly determine the transient power angle stability and instability mode of the half-wavelength power transmission system according to the constructed index system.
  • the effectiveness of the proposed method is verified by simulating faults using actual system parameters.
  • the fault of the test system is set at the line 2600km, the transmission power of the line before the fault is 1p.u, and the fault clearing time is 0.06s, 0.11s, 0.12s, 0.15s respectively, the phase trajectory curve of the generator during the fault occurs is shown in Figure 4 , where the generator angle shown in Figure 4 represents the power angle of the generator.
  • the fault limit removal time is within 0.11s, the phase trajectory curve converges to the initial state, and the system is stable; when the fault removal time is greater than 0.12s, the phase trajectory diverges.
  • the fault clearing time is 0.12s
  • the power angle of the generator at the sending end first shows a reverse swing trend
  • the second pendulum is positive swing
  • the swing is larger and the generator accelerates to an unstable state.
  • the fault clearing time increases to 0.15s, which is shown by the black curve, the generator will continue to decelerate to stop.
  • the two indexes mentioned in the present invention are both greater than zero at about 0.6s, reaching the criterion for judging instability.
  • the fault clearing time in Figure 5-13 is 0.11s, the two indicators do not appear to be greater than zero at the same time. It can be seen that the transient stability judgment method based on the concavity and convexity of the phase trajectory has good adaptability under critical fault conditions, and can be used to judge the instability of the half-wavelength transmission system.
  • a fast transient stability determination system for a half-wavelength power transmission system comprising:
  • the data acquisition unit is configured to, based on the wide-area measurement system and the phasor measurement unit, acquire the power and power angle of the generator at the sending end of the half-wavelength power transmission system;
  • the mode determination unit is configured to determine the transient power angle stability and its instability mode of the half-wavelength power transmission system by using the constructed index system;
  • the instability modes include two power angle instability modes for constructing a half-wavelength power transmission system based on the equal-area method, that is, instability mode 1 and instability mode 2.
  • the data acquisition unit and the mode determination unit can be one or more processors, controllers or chips with communication interfaces capable of implementing communication protocols, and can also include memory and related interface, system transmission bus, etc.; the processor, controller or chip executes program-related codes to realize corresponding functions.
  • the data acquisition unit and the mode determination unit share an integrated chip or share a processor, a controller, a memory and other devices.
  • the shared processor, controller or chip executes program-related codes to implement corresponding functions.
  • a computer-readable storage medium stores a plurality of instructions, and the instructions are suitable for being loaded and executed by a processor of a terminal device to execute a method for quickly determining transient stability of a half-wavelength power transmission system provided in this embodiment.
  • a terminal device includes a processor and a computer-readable storage medium, the processor is used to implement instructions; the computer-readable storage medium is used to store multiple instructions, and the instructions are suitable for being loaded and executed by the processor provided in Embodiment 1.
  • a fast transient stability determination method for half-wavelength power transmission systems includes a processor and a computer-readable storage medium, the processor is used to implement instructions; the computer-readable storage medium is used to store multiple instructions, and the instructions are suitable for being loaded and executed by the processor provided in Embodiment 1.
  • the embodiments of the present application may be provided as methods, systems, or computer program products. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) having computer-usable program code embodied therein.
  • computer-usable storage media including but not limited to disk storage, CD-ROM, optical storage, etc.
  • These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing apparatus to operate in a specific manner, such that the instructions stored in the computer-readable memory produce an article of manufacture comprising instruction means, the instructions
  • the device realizes the function specified in one or more procedures of the flowchart and/or one or more blocks of the block diagram.

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Abstract

本发明提供了一种半波长输电系统的暂态稳定快速判定方法及系统，所述方法包括：获取半波长输电系统送端发电机的功率及功角；利用所构建的指标体系判定半波长输电系统的暂态功角稳定性及其失稳模式；具体的，所述失稳模式包括基于等面积法构建半波长输电系统的两种功角失稳模态，即失稳模式1和失稳模式2。本发明基于等面积法构建了半波长输电系统所独有的两类失稳模式，能够准确描述半波长输电系统在严重故障下的暂态功角特性，而且其特性显著区别于传输交流输电方式。

Description

一种半波长输电系统的暂态稳定快速判定方法及系统 技术领域
本发明涉及力系统暂态功角稳定分析技术领域，尤其涉及一种半波长输电系统的暂态稳定快速判定方法及系统。
背景技术
本部分的陈述仅仅是提供了与本发明相关的背景技术信息，不必然构成在先技术。
半波长交流输电技术是指输电的电气距离接近1个工频半波，在50Hz下约为3000km的超远距离三相交流输电技术。半波长线路本身不发出或吸收无功功率的优势使其与传统特高压交流输电方式相比，输电系统结构更为简单，沿线无需提供额外的电压支撑设备；与特高压直流输电方式相比，避免了复杂的换流过程和谐波污染，设备的建造与维护更加简便。因此，半波长输电技术具有一定的研究前景，可以在未来电网构建中发挥一定的作用。
半波长输电线路存在最严重故障区域，当在这个区域附近发生短路故障时，引起线路沿线过电压的同时也会导致发电机电磁功率显著升高，电磁功率与机械功率的不平衡增加系统暂态失稳的风险。半波长输电线路长度通常略长于工频半波距离，在正常运行工况下，送、受端电气角度大约在180°左右。在现有的同步电网中，工程上常以最大发电机功角差大于一定限值作为判断系统稳定与否的依据，根据不同文献，该值通常在180°～360°。显然，该工程实用性判据并不适用于正常运行条件功角已经超过180°的半波长输电系统，需要寻求更具有一般性的稳定判定方法。
随着相量测量单元(PMU)以及广域测量系统WAMS的发展，实时地获取发电机轨迹信息已经成为可能。发电机实时轨迹信息直接反映了电力系统暂态稳定的程度，而且根据实测的轨迹信息进行实时暂态稳定性的分析和控制不依赖于模型和参数。
发明内容
本发明为了解决上述问题，提出了一种半波长输电系统的暂态稳定快速判定方法及系统，本发明能够根据发电机轨迹信息快速判定半波长输电系统的功角稳定性，并进行失稳模式分类。
根据一些实施例，本发明采用如下技术方案：
一种半波长输电系统的暂态稳定快速判定方法，包括：
获取半波长输电系统送端发电机的功率及功角；
利用所构建的指标体系判定半波长输电系统的暂态功角稳定性及其失稳模式；
具体的，所述失稳模式包括基于等面积法构建半波长输电系统的两种功角失稳模态，即失稳模式1和失稳模式2。
进一步地，所述失稳模式1中发电机持续减速失稳，失稳模式2中发电机先减速，后持续加速失稳。
进一步地，所述构建的指标体系包括：以发电机的功角为横坐标、发电机的角速度为纵坐标构建的发电机功角-角速度相平面曲线。
进一步地，所述构建的指标体系还包括：凸区域边界，凸区域边界是基于发电机功角-角速度相平面曲线的相轨迹的斜率随功角变化的变化率定义的相轨迹凹凸性构建。
进一步地，定义发电机轨迹向左平面移动，并穿过左侧凸区域边界为失稳模式1。
进一步地，定义发电机轨迹先向左平面移动，后向右平面移动并穿过右侧凸区域边界为失稳模式2。
进一步地，所述构建的指标体系还包括：表征拐点方向场的辅助指标；
则，利用所构建的指标体系判定半波长输电系统的暂态功角稳定性及其失稳模式，包括：
适应工程稳定性需要，构建判定指标离散化处理方法；
利用构建的判定指标离散化处理方法对所构建的指标体系进行离散化处理，以根据离散化处理后的指标体系判定半波长输电系统的暂态功角稳定性及其失稳模式。
一种半波长输电系统的暂态稳定快速判定系统，包括：
数据获取单元，被配置为，获取送半波长输电系统送端发电机的功率及功角；
模式判定单元，被配置为，利用所构建的指标体系判定半波长输电系统的暂态功角稳定性及其失稳模式；
具体的，所述失稳模式包括基于等面积法构建半波长输电系统的两种功角失稳模态，即失稳模式1和失稳模式2。
一种计算机可读存储介质，其中存储有多条指令，所述指令适于由终端设备的处理器加载并执行所述的一种半波长输电系统的暂态稳定快速判定方法。
一种终端设备，包括处理器和计算机可读存储介质，处理器用于实现各指令；计算机可读存储介质用于存储多条指令，所述指令适于由处理器加载并执 行所述的一种半波长输电系统的暂态稳定快速判定。
与现有技术相比，本发明的有益效果为：
本发明基于等面积法构建了半波长输电系统所独有的两类失稳模式，能够准确描述半波长输电系统在严重故障下的暂态功角特性，而且其特性显著区别于传输交流输电方式。
本发明构建了基于半波长输电系统送端发电机轨迹曲线的暂态稳定判断方法。基于发电机轨迹斜率随功角变化率定义轨迹凹凸性，并构建凸区域边界。根据发电机轨迹进入凸区域边界的方向及角度归类不同的失稳模式，保证了暂态稳定判断的准确性及可操作性。
本发明构建判定指标离散化处理方法，提出表征拐点方向场的辅助指标。为了适应工程数据离散化的特点，构建判断指标的离散化处理方法。另外通过构建表征拐点方向场的辅助指标，避免数据误差、励磁调节器、调频器等因素的影响，使暂态稳定的判断更具有鲁棒性。
附图说明
构成本申请的一部分的说明书附图用来提供对本申请的进一步理解，本申请的示意性实施例及其说明用于解释本申请，并不构成对本申请的不当限定。
图1是本实施例的流程图；
图2(a)是本实施例的半波长输电系统功角运行状态阶段1图；
图2(b)是本实施例的半波长输电系统功角运行状态阶段2图；
图3是本实施例的半波长输电线路区内不同故障切除时间下的相轨迹图；
图4是本实施例的测试条件下送端发电机相轨迹曲线图；
图5是本实施例的测试条件下暂稳判断指标时域变化图。
具体实施方式：
下面结合附图与实施例对本发明作进一步说明。
应该指出，以下详细说明都是例示性的，旨在对本申请提供进一步的说明。除非另有指明，本文使用的所有技术和科学术语具有与本申请所属技术领域的普通技术人员通常理解的相同含义。
需要注意的是，这里所使用的术语仅是为了描述具体实施方式，而非意图限制根据本申请的示例性实施方式。如在这里所使用的，除非上下文另外明确指出，否则单数形式也意图包括复数形式，此外，还应当理解的是，当在本说明书中使用术语“包含”和/或“包括”时，其指明存在特征、步骤、操作、器件、组件和/或它们的组合。
实施例1.
如图1所示，一种半波长输电系统的暂态稳定快速判定方法，包括以下步骤：
S1：基于等面积法构建半波长输电系统两种功角失稳模态，即失稳模式1：发电机持续减速失稳，失稳模式2：发电机先减速，后持续加速失稳；
S2：基于广域测量系统(WAMS)及相量测量单元(PMU)获取半波长输电系统送端发电机的功率及功角；发电机的功率包括：机械功率及电磁功率；
S3：以发电机的功角为横坐标，发电机的角速度为纵坐标，构建发电机功角-角速度相平面曲线；
S4：基于发电机功角-角速度相平面曲线的相轨迹的斜率随功角变化的变化率定义相轨迹凹凸性，并构建凸区域边界；
S5：定义发电机轨迹向左平面移动，并穿过左侧凸区域边界认定为步骤1中的失稳模式1；定义发电机轨迹先向左平面移动，后向右平面移动并穿过右侧 凸区域边界认定为步骤1中的失稳模式2；
S6：适应工程稳定性需要，构建判定指标离散化处理方法，提出表征拐点方向场的辅助指标。
S7：根据所构建的指标体系快速判定半波长输电系统的暂态功角稳定性及其失稳模式。
具体的，
S1：基于等面积法构建半波长输电系统两种功角失稳模态；
若忽略阻尼，送端等值机转子运动方程可以表示为：
Figure PCTCN2022110130-appb-000001
式中，ω 0为初始状态同步角速度；Δω为角速度变化量；T J为惯性时间常数；P m和P e(δ)分别为机械功率及电磁功率；δ为发电机的功角；t为时间。
忽略发电机调速器及阻尼的作用，且维持机械功率P m＝P e(δ 0)不变。设三相短路发生在t＝0时刻，故障清除时间为t c，故障清除后，假设系统结构及负荷状态与故障前保持一致。
图2显示故障条件下发电机电磁功率与功角的关系曲线，其中，图2(a)、图2(b)中所示的角度表示发电机的功角。图2(a)所示，当半波长线路最严重故障区域发生故障时，电磁功率会显著高于机械功率，系统运行点从a移动到b点，发电机功角会呈现出减小的趋势，获得减速面积A-。当故障在δ 1清除后，系统运行点从c移动到d点，有Δω<0且P m-P e(δ 0)>0，功角会在继续减小的同时获得加速面积A+，在e点，即功角δ 2时达到Δω＝0。在此刻，发电机机械功率大于电磁功率，如图2(b)所示，发电机获得加速面积B+，在超过初始功角δ 0后， 获得减速面积B-，系统运行点从e运行至f并最终达到g。如果不考虑阻尼作用，功角将在g到e点间振荡，如果考虑阻尼作用，角度将最终回到初始运行点δ 0。从上述分析可以发现，半波长输电线路最严重故障点附近存在两种功角失稳模式。首先，在运行阶段1，如果发电机功角运行至δ min时，获得的加速面积A+<A-，则发电机将继续获得减速面积，角速度也将继续减小至停机。如果存在δ 2>δ min时，获得的加速面积A+＝A-，则发电机开始反向加速，如果有B+＝B-，发电机将在阻尼的作用下回到初始运行状态，系统稳定；如果在发电机最大功角δ 3＝δ max时，有B+>B-，则发电机将继续加速至失稳。综上所述，半波长输电系统最严重故障处共有两种失稳模式，定义故障后发电机功角持续减小至停机状态为失稳模式1；定义发电机先减速，后加速至失稳状态为失稳模式2。
S2：基于广域测量系统(WAMS)及相量测量单元(PMU)获取半波长输电系统送端发电机的电磁功率及功角；
广域测量系统(WAMS)及相量测量单元(PMU)已广泛应用于电网状态监测领域，本发明通过利用该系统及装置采集的电网实时数据作为输入量。
S3：以发电机的功角为横坐标，发电机的角速度为纵坐标，构建发电机功角-角速度相平面曲线；
以功角δ为横坐标，角速度Δω为纵坐标，可以构建系统的功角-角速度(δ-Δω)相平面，发电机暂态过程可以表示为相平面上随时间变化的曲线，称为相轨迹。根据相轨迹可以分析系统稳定性，半波长输电线路在最严重故障点发生三相短路时，故障发生瞬间，电磁功率瞬间激升，呈现出负的不平衡功率，角速度呈减小趋势，发电机功角持续减小，若能够及时切除故障，则呈现出闭合相轨迹，系统稳定。如不能及时切除故障，发电机轨迹将发散失稳。
S4：基于发电机功角-角速度相平面曲线的相轨迹的斜率随功角变化的变化率定义相轨迹凹凸性，并构建凸区域边界；
半波长输电系统送端发电机的相轨迹的斜率推导为：
Figure PCTCN2022110130-appb-000002
式中，δ为发电机的功角，ω 0为初始状态同步角速度；Δω为角速度变化量；M为惯性常数，ΔP(δ)为电磁功率变化量。
相轨迹的斜率随功角变化的变化率推导为：
Figure PCTCN2022110130-appb-000003
相轨迹凹凸性定义为：1)vΔω<0，位于凹区域；2)vΔω>0，位于凸区域；3)vΔω＝0，位于两区域交界处。凸区域边界推导进一步为：
Figure PCTCN2022110130-appb-000004
式中ΔP'(δ)为不平衡功率对功角的一阶导数。
在相平面绘制的发电机的相轨迹及凹凸性边界如图3所示，快速的故障清除时间可以使轨迹出现拐点，从而出现呈顺时针走向的闭合轨迹，系统保持稳定；若无法在极限时间内清除故障，则功角将沿原有的运行趋势继续加速或减速，导致系统失稳。虽然半波长线路送、受端功角差在正常运行时就已经超过180°，但是通过观察相轨迹曲线可以发现，系统的失稳与否与功角差的绝对大小并不直接相关，而受故障清除时间、负荷水平及发电机动态特性等因素的综合影响。因此，分析故障发生后的相轨迹特性可以用于半波长输电系统暂态稳定性的判断，避免了采用功角差绝对值判断方法可能带来的误判。
S5：定义发电机的相轨迹向左平面移动，并穿过左侧凸区域边界认定为步 骤1中的失稳模式1；定义发电机的相轨迹先向左平面移动，后向右平面移动并穿过右侧凸区域边界认定为步骤1中的失稳模式2；
根据图3给出的示意图，绘制相轨迹拐点v＝0的位置，见图中所示。需要指出的是，半波长系统的精确功角表达式包含双曲函数，难于解析，求得的拐点曲线为数值解。当故障无法及时清除，导致相轨迹进入阴影的凸区域后，判定为系统失稳。如图所示，故障切除时间为t1时，发电机的相轨迹为闭合曲线，认定为系统稳定；故障切除时间为t3时，发电机的相轨迹向左平面移动，并穿过左侧凸区域边界，认定为系统失稳，并定义为失稳模式1；故障切除时间为t2时，发电机轨迹先向左平面移动，后向右平面移动并穿过右侧凸区域边界，认定为系统失稳，并定义为失稳模式2。
S6：适应工程稳定性需要，构建判定指标离散化处理方法，提出表征拐点方向场的辅助指标；
上述稳定性判断公式是基于模型给出的，为了适应基于响应的稳定性判断，需要对判定指标进行离散化处理。离散化后的判断指标为：
Figure PCTCN2022110130-appb-000005
Figure PCTCN2022110130-appb-000006
由于半波长输电系统的电磁曲线不再是理想情况下的正弦关系，另外考虑到发电机励磁调节器、调频器等因素的影响，相轨迹穿越拐点曲线后其方向场的方向不再唯一，等值相轨迹进入凸区域后，也存在使其重新返回凹区域的可能。因此，只采用单一指标可能会出现误判情况。提出表征拐点方向场的辅助指标r。现定义辅助指标r为：
Figure PCTCN2022110130-appb-000007
离散后的工程辅助判断指标为：
r(i)＝ΔP'(i)-ΔP'(i-1)＞0
Figure PCTCN2022110130-appb-000008
式中，ΔP’(i)为电磁功率变化量一阶导数。
S7：根据所构建的指标体系快速判定半波长输电系统的暂态功角稳定性及其失稳模式。
现利用实际系统参数进行模拟故障验证所提方法的有效性。测试系统故障设置在线路2600km处，故障前线路传输功率为1p.u，故障清除时间分别为0.06s、0.11s、0.12s、0.15s时，故障发生过程中发电机相轨迹曲线如图4所示，其中，图4中所示的发电机角度表示发电机的功角。当故障极限切除时间在0.11s以内时，相轨迹曲线收敛至初始状态，系统稳定；当故障清除时间大于0.12s，相轨迹发散。与前述的分析结论类似，当前运行状态存在两种不同的失稳模式，图绿色曲线所示，故障清除时间0.12s，送端发电机功角先呈现反摆趋势，而第二摆的正摆摆幅更大，发电机加速至失稳状态。当故障清除时间增加至0.15s时，即黑色曲线所示，发电机将持续减速至停机。
图5所示故障清除时间为0.12s时，本发明所提的两项指标在0.6s左右均大于零，达到判定失稳的标准。而图5-13故障清除时间为0.11s时，两项指标未出现同时大于零的情况。由此可见基于相轨迹凹凸性的暂态稳定判定方法在临界故障条件下具有较好的适应性，可以用于半波长输电系统的失稳判断。
实施例2.
一种半波长输电系统的暂态稳定快速判定系统，包括：
数据获取单元，被配置为，基于广域测量系统和相量测量单元，获取送半波长输电系统送端发电机的功率及功角；
模式判定单元，被配置为，利用所构建的指标体系判定半波长输电系统的暂态功角稳定性及其失稳模式；
具体的，所述失稳模式包括基于等面积法构建半波长输电系统的两种功角失稳模态，即失稳模式1和失稳模式2。
在本申请的实施例中，所述数据获取单元，模式判定单元，分别可以是具有通信接口能够实现通信协议的一个或多个处理器、控制器或者芯片，如有需要还可以包括存储器及相关的接口、系统传输总线等；所述处理器、控制器或者芯片执行程序相关的代码实现相应的功能。或者，可替换的方案为，所述数据获取单元，模式判定单元共享一个集成芯片或者共享处理器、控制器、存储器等设备。所述共享的处理器、控制器或者芯片执行程序相关的代码实现相应的功能。
实施例3.
一种计算机可读存储介质，其中存储有多条指令，所述指令适于由终端设备的处理器加载并执行本实施例提供的一种半波长输电系统的暂态稳定快速判定方法。
实施例4.
一种终端设备，包括处理器和计算机可读存储介质，处理器用于实现各指令；计算机可读存储介质用于存储多条指令，所述指令适于由处理器加载并执行本实施例一提供的一种半波长输电系统的暂态稳定快速判定方法。
本领域内的技术人员应明白，本申请的实施例可提供为方法、系统、或计算机程序产品。因此，本申请可采用完全硬件实施例、完全软件实施例、或结合软件和硬件方面的实施例的形式。而且，本申请可采用在一个或多个其中包含有计算机可用程序代码的计算机可用存储介质(包括但不限于磁盘存储器、CD-ROM、光学存储器等)上实施的计算机程序产品的形式。
本申请是参照根据本申请实施例的方法、设备(系统)、和计算机程序产品的流程图和/或方框图来描述的。应理解可由计算机程序指令实现流程图和/或方框图中的每一流程和/或方框、以及流程图和/或方框图中的流程和/或方框的结合。可提供这些计算机程序指令到通用计算机、专用计算机、嵌入式处理机或其他可编程数据处理设备的处理器以产生一个机器，使得通过计算机或其他可编程数据处理设备的处理器执行的指令产生用于实现在流程图一个流程或多个流程和/或方框图一个方框或多个方框中指定的功能的装置。
这些计算机程序指令也可存储在能引导计算机或其他可编程数据处理设备以特定方式工作的计算机可读存储器中，使得存储在该计算机可读存储器中的指令产生包括指令装置的制造品，该指令装置实现在流程图一个流程或多个流程和/或方框图一个方框或多个方框中指定的功能。
这些计算机程序指令也可装载到计算机或其他可编程数据处理设备上，使得在计算机或其他可编程设备上执行一系列操作步骤以产生计算机实现的处理，从而在计算机或其他可编程设备上执行的指令提供用于实现在流程图一个流程或多个流程和/或方框图一个方框或多个方框中指定的功能的步骤。
以上所述仅为本申请的优选实施例而已，并不用于限制本申请，对于本领域的技术人员来说，本申请可以有各种更改和变化。凡在本申请的精神和原则 之内，所作的任何修改、等同替换、改进等，均应包含在本申请的保护范围之内。
上述虽然结合附图对本发明的具体实施方式进行了描述，但并非对本发明保护范围的限制，所属领域技术人员应该明白，在本发明的技术方案的基础上，本领域技术人员不需要付出创造性劳动即可做出的各种修改或变形仍在本发明的保护范围以内。

Claims (10)

  1. 一种半波长输电系统的暂态稳定快速判定方法，其特征在于，包括：
    获取半波长输电系统送端发电机的功率及功角；
    利用所构建的指标体系判定半波长输电系统的暂态功角稳定性及其失稳模式；
    具体的，所述失稳模式包括基于等面积法构建半波长输电系统的两种功角失稳模态，即失稳模式1和失稳模式2。
  2. 如权利要求1所述的一种半波长输电系统的暂态稳定快速判定方法，其特征在于，所述失稳模式1中发电机持续减速失稳，失稳模式2中发电机先减速，后持续加速失稳。
  3. 如权利要求2所述的一种半波长输电系统的暂态稳定快速判定方法，其特征在于，所述构建的指标体系包括：以发电机的功角为横坐标、发电机的角速度为纵坐标的发电机功角-角速度相平面曲线。
  4. 如权利要求3所述的一种半波长输电系统的暂态稳定快速判定方法，其特征在于，所述构建的指标体系还包括：凸区域边界，所述凸区域边界是基于发电机功角-角速度相平面曲线的相轨迹的斜率随功角变化的变化率所定义的相轨迹凹凸性构建。
  5. 如权利要求4所述的一种半波长输电系统的暂态稳定快速判定方法，其特征在于，定义发电机的相轨迹向左平面移动，并穿过左侧凸区域边界为失稳模式1。
  6. 如权利要求5所述的一种半波长输电系统的暂态稳定快速判定方法，其特征在于，定义发电机的相轨迹先向左平面移动，后向右平面移动并穿过右侧凸区域边界为失稳模式2。
  7. 如权利要求6所述的一种半波长输电系统的暂态稳定快速判定方法，其特征在于，所述构建的指标体系还包括：表征拐点方向场的辅助指标；
    则，利用所构建的指标体系判定半波长输电系统的暂态功角稳定性及其失稳模式，包括：
    适应工程稳定性需要，构建判定指标离散化处理方法；
    利用构建的判定指标离散化处理方法对所构建的指标体系进行离散化处理，以根据离散化处理后的指标体系判定半波长输电系统的暂态功角稳定性及其失稳模式。
  8. 一种半波长输电系统的暂态稳定快速判定系统，其特征在于，包括：
    数据获取单元，被配置为，获取半波长输电系统送端发电机的功率及功角；
    模式判定单元，被配置为，利用所构建的指标体系判定半波长输电系统的暂态功角稳定性及其失稳模式；
    具体的，所述失稳模式包括基于等面积法构建半波长输电系统的两种功角失稳模态，即失稳模式1和失稳模式2。
  9. 一种计算机可读存储介质，其特征在于，其中存储有多条指令，所述指令适于由终端设备的处理器加载并执行权利要求1-7中任一项所述的一种半波长输电系统的暂态稳定快速判定方法。
  10. 一种终端设备，其特征在于，包括处理器和计算机可读存储介质，处理器用于实现各指令；计算机可读存储介质用于存储多条指令，所述指令适于由处理器加载并执行权利要求1-7中任一项所述的一种半波长输电系统的暂态稳定快速判定方法。
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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108092304A (zh) * 2017-12-06 2018-05-29 昆明理工大学 基于相轨迹与相对动能变化率的电力系统暂态稳定性判别方法
CN114336586A (zh) * 2021-11-04 2022-04-12 国网山东省电力公司电力科学研究院 一种半波长输电系统的暂态稳定快速判定方法及系统

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108092304A (zh) * 2017-12-06 2018-05-29 昆明理工大学 基于相轨迹与相对动能变化率的电力系统暂态稳定性判别方法
CN114336586A (zh) * 2021-11-04 2022-04-12 国网山东省电力公司电力科学研究院 一种半波长输电系统的暂态稳定快速判定方法及系统

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
"Doctoral Dissertation", 28 May 2020, SHAN DONG UNIVERSITY, CN, article TIAN HAO: "Studies on Operation Characteristics and Voltage Control of UHV Half-Wavelength Transmission System", pages: 1 - 126, XP009545598, DOI: 10.27272/d.cnki.gshdu.2020.000339 *
BAOHUI ZHANG, YANG SONGHAO, WANG HUAIYUAN: "Power System Transient Stability Closed-loop Control (1)—— Principles of Transient Instability Discrimination in Simple Power Systems", ELECTRIC POWER AUTOMATION EQUIPMENT, vol. 38, no. 4, 8 August 2014 (2014-08-08), pages 1 - 6, XP093063438 *

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