阅读说明：本技术 一种基于黎曼积分的谐波排吸占比分析方法和装置 (Riemann integral-based harmonic elimination and absorption ratio analysis method and device ) 是由 张海江 张建宇 陈龙 杨立 柏玉墙 谢斌 鲁峰 于 2019-10-23 设计创作，主要内容包括：本发明提供一种基于黎曼积分的谐波排吸占比分析方法和装置,包括如下步骤：(1)搜集多个监测点的谐波历史数据：通过谐波监测装置搜集到多个监测点的谐波历史数据,并存入文件；(2)计算各监测点的吸收或排放电能：基于多个监测点的谐波历史数据,利用黎曼积分法计算出各监测点谐波的吸收或排放量；(3)计算各监测点的排吸占比：根据各监测点的吸收或排放电能,计算出各监测点的排吸占比。本发明另提供一种基于黎曼积分的谐波排吸占比分析装置,完成上述方法的实现,同时展示并导出分析结果。本发明可以快速地得到区域电网内的谐波排放和吸收情况,为谐波的分布与流向分析提供有效的参考依据。(The invention provides a harmonic elimination and absorption ratio analysis method and device based on Riemann integral, comprising the following steps: (1) collecting harmonic history data of a plurality of monitoring points: harmonic history data of a plurality of monitoring points are collected through a harmonic monitoring device and stored in a file; (2) calculating the absorption or emission electric energy of each monitoring point: calculating the absorption or discharge amount of the harmonic waves of each monitoring point by utilizing a Riemann integral method based on the harmonic wave historical data of the monitoring points; (3) calculating the ratio of the discharge to the suction of each monitoring point: and calculating the discharge and suction ratio of each monitoring point according to the absorption or discharge electric energy of each monitoring point. The invention further provides a harmonic rejection and absorption ratio analysis device based on Riemann integral, the implementation of the method is completed, and the analysis result is displayed and derived at the same time. The method can quickly obtain the harmonic emission and absorption conditions in the regional power grid, and provides an effective reference basis for the distribution and flow direction analysis of the harmonic.)

1. A harmonic elimination and absorption ratio analysis method and device based on Riemann integral are characterized by comprising the following steps:

s1, collecting harmonic history data of a plurality of monitoring points: harmonic history data of a plurality of monitoring points are collected through a harmonic monitoring device and stored in a file;

s2, calculating the absorption or discharge electric energy of each monitoring point: calculating the absorption or discharge amount of the harmonic waves of each monitoring point by utilizing a Riemann integral method based on the harmonic wave historical data of the monitoring points;

s3, calculating the ratio of the drainage to the suction of each monitoring point: and calculating the discharge and suction ratio of each monitoring point according to the absorption or discharge electric energy of each monitoring point.

2. The method and apparatus for analysis of harmonic absorption and emission ratios based on riemann integration according to claim 1, wherein in the step S1, the harmonic history data comprises: harmonic voltage of 2-50 times, current amplitude, harmonic voltage of 2-50 times, current phase angle, and active and reactive power of 2-50 times.

3. The method and apparatus for harmonic rejection ratio analysis based on Riemann integral as claimed in claim 1, wherein the apparatus is used to implement the above analysis method, and can display and derive the analysis results.

Technical Field

The invention relates to the field of harmonic analysis of a power system, in particular to a harmonic discharge and absorption ratio analysis method and device based on Riemann integral.

Background

With the rapid growth of extra-high voltage direct current, wind power photovoltaic, electrified railways and other nonlinear loads, the problem of the power quality of the power grid is increasing day by day, and the problem of the power quality is paid extensive attention under the background. The harmonic pollution is always the most prominent and most concerned problem of the power quality, and therefore, the key point for solving the problem of the power quality is to solve the harmonic problem of a power grid.

The harmonic problem is solved by firstly figuring out the distribution and the flow direction of the harmonic of the power grid. At present, monitoring/testing is the only means for comprehensively controlling the current situation of the harmonic wave of the power grid, and the common method is field measurement of a harmonic wave monitoring device and construction of a harmonic wave monitoring system. However, the method still stays in the out-of-limit statistics and event alarm stages, so that subsequent harmonic treatment is difficult to develop, and after monitoring data are obtained, manual intervention is needed to perform harmonic analysis and obtain information such as reports. Therefore, how to accurately and quickly find out the distribution and the flow direction of the power grid harmonic waves becomes a focus of attention of power grid harmonic wave researchers.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention provides a harmonic discharge and absorption ratio analysis method and device based on Riemann integral, which can quickly obtain the harmonic discharge and absorption conditions in a regional power grid and provide an effective reference basis for harmonic distribution and flow direction analysis.

The invention provides a harmonic elimination and absorption ratio analysis method based on Riemann integral, which comprises the following steps:

s1, collecting harmonic history data of a plurality of monitoring points: harmonic history data of a plurality of monitoring points are collected through a harmonic monitoring device and stored in a file;

s2, calculating the absorption or discharge electric energy of each monitoring point: calculating the absorption or discharge amount of the harmonic waves of each monitoring point by utilizing a Riemann integral method based on the harmonic wave historical data of the monitoring points;

the electric energy absorbed or emitted by the electric equipment in a certain time period is represented by symbol W, the calculation formula of the electric energy is W ═ Pt (P is active power, t is statistical time), if a function f (t) ═ Pt exists, the constant integral of f (t) in a time period [ a, b ] is:

according to the riemann integration principle, the electric energy W can be understood as the area value of a curved trapezoid surrounded by a curve (t, f (t)), a straight line t ═ a, t ═ b, and an abscissa axis on a coordinate plane;

at present, it is assumed that a certain substation has N monitoring points M1-MN, and in a time period t, h-order harmonic electric energy emitted and absorbed by each monitoring point is as follows in sequence:

W_ph1，W_ph2，W _ph3，…W_phN

W_xh1，W_xh2，W _xh3，…W_xhN

s3, calculating the ratio of the drainage to the suction of each monitoring point: calculating the discharge-suction ratio of each monitoring point according to the absorption or discharge electric energy of each monitoring point;

then, during time period t, h-th harmonic emission duty ratio P of monitoring point M1_ph1. Absorption ratio P_xh1 is defined as:

h-th harmonic emission, absorption ratio of monitoring point M2-MN and so on.

The invention also aims to provide a harmonic elimination and absorption ratio analysis device based on Riemann integral, which integrates an analysis method, realizes the harmonic elimination and absorption ratio analysis of the monitoring point, and simultaneously displays and derives the analysis result.

Compared with the prior art, the invention has the following advantages and effects:

1. the invention provides a harmonic emission and absorption ratio analysis method based on Riemann integral, which is rigorous in theory, can quickly analyze the harmonic emission and absorption ratio of a monitoring point and is convenient for practical engineering application;

2. the invention also provides a harmonic elimination and absorption ratio analysis device based on Riemann integral, which can realize the method, display and derive the analysis result and provide an effective reference basis for the distribution and flow direction analysis of the harmonic.

Drawings

FIG. 1 is a flow chart of an analytical method;

FIG. 2 is a schematic view of the structure of the analyzer;

FIG. 3 shows the results of analysis of an embodiment of the present invention.

The specific implementation mode is as follows:

the present invention will be described in detail with reference to examples.

The embodiment aims to provide a method and a device for analyzing the harmonic elimination and absorption ratio based on Riemann integral, so as to realize the analysis of the harmonic elimination and absorption ratio of a monitoring point, and the specific implementation is as follows:

s1, collecting harmonic history data of a plurality of monitoring points: the method comprises the following steps of collecting minute-level harmonic historical data of 10 monitoring points (lines) in a certain 35kV transformer substation continuously for one day through a harmonic monitoring device, and storing the minute-level harmonic historical data into a file;

s2, calculating the absorption or discharge electric energy of each monitoring point: calculating the absorption or discharge amount of the harmonic waves of each monitoring point by utilizing a Riemann integral method based on the harmonic wave historical data of 10 monitoring points;

the electric energy absorbed or emitted by the electric equipment in a certain time period is represented by symbol W, the calculation formula of the electric energy is W ═ Pt (P is active power, t is statistical time), if a function f (t) ═ Pt exists, the constant integral of f (t) in a time period [ a, b ] is:

according to the riemann integration principle, the electric energy W can be understood as the area value of a curved trapezoid surrounded by a curve (t, f (t)), a straight line t ═ a, t ═ b, and an abscissa axis on a coordinate plane;

taking 5-harmonic as an example, the 5-harmonic electric energy emitted and absorbed by 10 monitoring points of the transformer substation within 1 day sequentially comprises:

W_ph1，W_ph2，W _ph3，…W_phN

W_xh1，W_xh2，W _xh3，…W_xhN

s3, calculating the ratio of the drainage to the suction of each monitoring point: calculating the discharge-suction ratio of each monitoring point according to the absorption or discharge electric energy of each monitoring point;

then, the 5 th harmonic emission ratio P of a single monitoring point in 1 day_ph1. Absorption ratio P_xh1 is defined as:

the 5 th harmonic emission and absorption ratios of other monitoring points are analogized, and the analysis result is shown in figure 3.

Finally, it should be noted that the above-mentioned examples, although describing particular embodiments in conjunction with the drawings, are not intended to limit the implementation of the present invention, and those skilled in the art who refer to the above-mentioned examples may modify or replace the particular embodiments of the present invention without inventive step, without departing from the spirit of the present invention, which is within the scope of the claims.