CN102103160A - Method, system and detection controller for residual current monitoring and alarming - Google Patents

Abstract

The invention provides a residual current monitoring and alarming method, a residual current monitoring and alarming system and a detection controller. The method comprises the following steps: collecting a three-phase load current value and a residual current value of a monitored loop; generating and storing a residual current relative value of each acquisition time point according to the acquired load current value and residual current value; carrying out statistical analysis on a plurality of residual current relative values within a preset time length, and generating and storing statistical parameters of the plurality of residual current relative values; generating an alarm threshold value of the monitoring time point according to the residual current relative value stored before the monitoring time point and the statistical parameter; and monitoring and alarming the residual current of the monitoring loop according to the generated alarm threshold value. The residual current monitoring alarm method, the residual current monitoring alarm system and the detection controller can avoid missed alarm and false alarm caused by the existing fixed alarm threshold value.

Description

Method, system and detection controller for residual current monitoring and alarming

technical field

The invention relates to the technical field of residual current electrical fire monitoring, in particular to a residual current monitoring and alarming method, system and detection controller.

Background technique

The residual current electrical fire monitoring system is a new product that has appeared in recent years. It is installed in the low-voltage power distribution system and its core function is to prevent electrical fires. In view of the serious situation of electrical fires in my country in the past ten years and the obvious improvement of fire prevention awareness in all sectors of society, the application of residual current electrical fire monitoring and alarm systems has developed very rapidly, especially in public buildings and high-rise buildings. The role of the residual current electrical fire monitoring system in preventing electrical fires has been gradually recognized by all parties, and has a very good application prospect.

The residual current electrical fire monitoring system monitors the residual current of the protected circuit in real time. Once the detected residual current exceeds the set alarm threshold, an alarm signal is issued. The alarm principle is very simple. It is precisely because the alarm algorithm is simple and there is no consideration of intelligence, the residual current electrical fire monitoring system has considerable defects in alarm accuracy and reliability. In actual use, there are cases of missed alarms and false alarms. Complete.

The existing residual current electrical fire monitoring system adopts a simple alarm algorithm of fixed alarm threshold, which is the essential reason for frequent false alarms and missing alarms in the system. The setting of the alarm threshold has nothing to do with the change characteristics of the normal residual current of the protected power distribution system, and once set, it cannot be changed automatically and must be reset manually.

Fixed alarm thresholds fundamentally have two disadvantages:

(1) Improper alarm threshold setting

Fig. 1 is one of the principle schematic diagrams of residual current alarm in the prior art. As shown in Figure 1, if the alarm threshold is set too high (alarm setting value 2), far exceeding the maximum value of the normal residual current, even if the power distribution system has an abnormal residual current in the area where point B is located, the alarm threshold is not exceeded. Threshold, the system will not alarm, resulting in leakage alarm; if the alarm threshold is set too low (alarm setting value 1), when the normal residual current in the power distribution system increases to near the maximum value, such as the area where point A is located, it is easy to cause False alarm.

(2) The relative alarm sensitivity is inconsistent

Fig. 2 is the second schematic diagram of the residual current alarm principle in the prior art. If the difference between the alarm threshold and the normal residual current value is defined as the relative alarm sensitivity (Δh1 and Δh2 in Figure 2), in the case of a fixed alarm threshold, the relative alarm sensitivity is not always consistent, but increases with the residual current normal fluctuations. Figure 2 takes the alarm setting value 1 as the reference threshold, and the relative alarm sensitivity difference between point A and point B is relatively large, which may also cause false alarms and missed alarms. When running at low load (the flat area where point A is in Figure 2), even if there is an abnormal residual current, it may not be able to alarm because Δh1 is too large; when running at high load (the area where point B is in Figure 2), even if there is no abnormality For residual current, because Δh2 is too small, a small fluctuation of normal residual current may also cause an alarm.

From the above analysis, it can be seen that the reason for the existence of missed alarms and false alarms in the prior art is determined by the congenital deficiency of the fixed alarm threshold. Alarm and leak alarm.

Contents of the invention

The purpose of the present invention is to provide a method, device and system for monitoring and alarming residual current. The method, device and system can dynamically determine the residual current alarm threshold, effectively solving the problems of missed alarms and false alarms caused by the use of fixed alarm thresholds in the prior art.

An embodiment of the present invention provides a residual current monitoring and alarm method, the method comprising: collecting the three-phase load current value and residual current value of the monitored circuit; generating and storing each Collecting the relative value of residual current at the time point; performing statistical analysis on multiple relative values of residual current within a preset period of time, generating and storing statistical parameters of the multiple relative values of residual current; The relative value of the residual current and the statistical parameters generate an alarm threshold at the monitoring time point; and monitor and alarm the residual current of the monitoring loop according to the generated alarm threshold.

Another embodiment of the present invention provides a residual current monitoring and alarm system. The system includes: a centralized controller, a bus isolator, a detection controller, a current detector, and a residual current detector; connected to the detection controller; the detection controller is connected to the current detector and the residual current detector; the current detector is used to collect the three-phase load current; the residual current detector is used to collect the residual current; The detection controller is used to generate and store the relative value of residual current at each collection time point according to the collected load current value and residual current value; perform statistical analysis on multiple relative residual current values within a preset time length, generate and store Storing the statistical parameters of the multiple residual current relative values; generating an alarm threshold at the monitoring time point according to the stored residual current relative values and the statistical parameters before the monitoring time point; Monitor and alarm the residual current of the circuit.

Another embodiment of the present invention provides a detection controller, the detection controller includes: a collection processing unit, used to generate and store the residual current at each collection time point according to the collected three-phase load current value and residual current value Relative value; Statistical analysis unit, used to perform statistical analysis on multiple residual current relative values within a preset time length, generate and store statistical parameters of the multiple residual current relative values; Threshold value generation unit, Used for monitoring time according to The relative value of the residual current and the statistical parameters stored before the point generate an alarm threshold at the monitoring time point; the monitoring alarm unit is used to monitor and alarm the residual current of the monitoring circuit according to the generated alarm threshold.

The residual current monitoring and alarming method, device and system of the present invention dynamically determine the alarm threshold on the basis of intelligent learning, fully considering the characteristics of the normal residual current change of the protected object. The residual current alarm threshold determined by the method, device and system of this embodiment is more reasonable and scientific, and can avoid missed alarms and false alarms caused by existing fixed alarm thresholds.

Description of drawings

Fig. 1 is one of schematic diagrams of residual current alarm principle in the prior art;

Fig. 2 is the second schematic diagram of the residual current alarm principle in the prior art;

Fig. 3 is the overall flowchart of the method of embodiment 1 of the present invention;

Fig. 4 is a schematic diagram of the residual current alarm principle of Embodiment 1 of the present invention;

Fig. 5 is the detailed flowchart of the method of embodiment 1 of the present invention;

Fig. 6 is a system schematic diagram of Embodiment 2 of the present invention;

7 is a functional block diagram of a detection controller according to Embodiment 2 of the present invention;

FIG. 8 is a detailed block diagram of the threshold generation unit 703 according to Embodiment 2 of the present invention.

Detailed ways

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments It is a part of embodiments of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

Example 1:

This embodiment provides a residual current monitoring and alarming method, the purpose of which is to intelligentize the determination of the alarming threshold through the follow-up technology of the alarming threshold, and to make dynamic adjustments, thereby avoiding the residual current electrical fire monitoring system that uses a fixed alarming threshold. It can improve the reliability and accuracy of the alarm in essence.

Figure 3 is the overall flow chart of the method. As shown in Figure 1, the method of the present embodiment includes:

S301. Collect the three-phase load current value and residual current value of the monitored circuit.

S302. Generate and store a relative value of residual current at each collection time point according to the collected load current value and residual current value.

Optionally, the relative value of the residual current in this embodiment is a ratio of the residual current value at the same moment to the vector sum of the three-phase load currents at the same moment.

S303. Statistically analyze the plurality of relative residual current values within a preset time period, and generate and store statistical parameters of the plurality of relative residual current values.

Optionally, the preset duration in this embodiment may be one day, and the statistical parameters include standard deviations of relative values of residual currents within one day.

Optionally, the preset duration in this embodiment may also be a plurality of subdivided periods within a day, and the statistical parameters further include an average value and a standard deviation of a plurality of relative residual current values in each subdivided period.

S304. Generate an alarm threshold at the monitoring time point according to the relative value of the residual current and the statistical parameters stored before the monitoring time point.

Depending on the actual situation, S304 may specifically include: generating an alarm threshold at the corresponding monitoring time point of the day according to the relative values of the residual current at multiple collection time points of the previous day and the standard deviation of the previous day; The relative value of the residual current and the standard deviation of the previous day, generate the alarm threshold of the corresponding monitoring time point of the day; or, according to the relative value of the residual current of multiple collection time points on the same day last week and the standard deviation of the same day last week, Generate alarm thresholds at the corresponding monitoring time points of the day.

Optionally, the alarm threshold in this embodiment is the sum of the relative value of the residual current and the standard deviation; or, the alarm threshold is the sum of the relative value of the residual current and an integer multiple of the standard deviation.

Optionally, the method further includes: according to the statistical parameter characteristics of the subdivided period, determining the relative value and standard deviation of the residual current used to generate the alarm threshold at the monitoring time point, and determining the specific method used in S304 according to the determined result. The alarm threshold generation method.

S305. Monitor and alarm the residual current of the monitoring loop according to the generated alarm threshold.

Optionally, S305 in this embodiment may specifically include: if the relative value of the residual current at the monitoring time point is greater than the alarm threshold, stop updating the alarm threshold and continue to determine whether the relative value of the residual current at the next monitoring time point is greater than Alarm threshold, if n consecutive relative values of residual current are greater than the alarm threshold, an alarm will be issued, wherein n is a positive integer (eg n=3).

The method of the invention can be specifically divided into intelligent learning process, statistical analysis process, dynamic adjustment process and real-time alarm process. Among them: (1) Intelligent learning process: intelligently analyze the collected current and residual current data, filter unreasonable data, and calculate the relative value of residual current. (2) Statistical analysis process: introduce statistical principles to analyze the change characteristics of the relative value of residual current, and find the average value and standard deviation of the relative value of residual current in different time periods; (3) Dynamic adjustment process: consider the relative value of residual current to reflect According to the periodicity of daily and weekly changes, the alarm threshold is determined according to the average value and standard deviation of the relative value of the residual current, and the alarm threshold is dynamically adjusted in real time; (4) Real-time alarm process: judging whether the alarm should be detected is no longer based on a detection value Exceeding the alarm setting value is the criterion, but taking n (eg n=3) consecutive detection values exceeding the alarm setting value as the criterion. In addition, when the relative value of the residual current used to determine the alarm threshold is 0, the load current must also be included in the judgment. How each process works is described in detail below.

(1) Intelligent-Learn process (Intelligent-Learn), intelligent learning is divided into initial intelligent learning and subsequent real-time intelligent learning.

The initial intelligent learning time is 24 hours on the first day. For each protected circuit, 3 load current data (1 for each phase) and 1 residual current data are collected per second; continue intelligent learning for 1 hour on the second day, At this point, the initial intelligent learning is all completed.

Optionally, in order to ensure the rationality of the data, the following process is performed for the load current and residual current data obtained in the 24 hours of initial intelligent learning:

A1. Filter out unreasonable three-phase load current and residual current data;

B1. After filtering out the unreasonable three-phase load current and residual current data, the vacancy left is based on one reasonable data before and after the unreasonable data, and according to the number of vacancies, interpolation method is used to obtain and supplement to ensure the integrity of the data quantity .

The relative value of the residual current refers to the ratio of the residual current value to the phasor sum of the three-phase load current at the same moment, as shown in the following formula:

${\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; RC</span>}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; I</span>}}_{\mathrm{<span\; class="notranslate">\; RC</span>}}}{{\stackrel{<span\; class="notranslate">\; \&Center\; Dot;</span>}{\mathrm{<span\; class="notranslate">\; I</span>}}}_{\mathrm{<span\; class="notranslate">\; A</span>}}<span\; class="notranslate">\; +</span>{\stackrel{<span\; class="notranslate">\; \&Center\; Dot;</span>}{\mathrm{<span\; class="notranslate">\; I</span>}}}_{\mathrm{<span\; class="notranslate">\; B</span>}}<span\; class="notranslate">\; +</span>{\stackrel{<span\; class="notranslate">\; \&Center\; Dot;</span>}{\mathrm{<span\; class="notranslate">\; I</span>}}}_{\mathrm{<span\; class="notranslate">\; C</span>}}}$

In the formula:

R _RC ——relative value of residual current;

I _RC - residual current test value of the protected circuit, (mA);

——被保护回路三相负荷电流的相量值，(A)。

——The phasor value of the three-phase load current of the protected circuit, (A).

Optionally, in order to ensure the rationality of the data, the calculation of the relative value of the residual current takes the following considerations:

A2. For the collected data, if three or more groups of three-phase load currents are completely equal in magnitude and three consecutive residual current values at the corresponding time are greater than zero, the relative value of the residual current will not be calculated, and the residual current value at the corresponding time will be saved as a reference judgment value;

B2. For the collected data, no matter how much the combined value of the three-phase load current is, as long as the residual current value is zero, the relative value of the residual current is zero;

C2. Considering the characteristics of residual current in different time periods, after filtering out the unreasonable relative value data of residual current in different time periods, the gaps left are calculated according to the number of gaps and one reasonable data before and after the unreasonable data. Supplement later to ensure the integrity of the data quantity.

The premise of initial intelligent learning is that the power distribution system operates normally during this process, and there is no possibility of abnormal residual current, so as to ensure that the data obtained by intelligent learning can be used as the basic reference data for judging abnormalities.

Real-time intelligent learning includes: from the 2nd to 24th hours of the second day, collect 4 current data every second to generate the relative value of residual current; during the 24 hours on the third day, collect 4 current data every second Collect and generate the relative value of residual current; ...; 24 hours on the 7th day, collect 4 current data every second to generate the relative value of residual current; The collection of current data generates the relative value of residual current; the data collected at the 2nd hour of the 8th day begins to replace the data of the 1st hour of the first day, and a total of 7 days and 1 hour of data are stored.

(2) Statistical Analysis Process (Statistics-Analysis)

和标准差σ_h1/d1；获得第1天第2个小时的剩余电流相对值的平均值和标准差σ_h2/d1；……；直到第1天第24小时的剩余电流相对值的平均值

和标准差σ_h24/d1；A3. According to the relative value of residual current calculated within 24 hours obtained by the initial intelligent learning, the average value of the relative value of residual current in the first hour of the first day is obtained

and standard deviation σ _h1/d1 ; obtain the average value of the relative value of the residual current on the first day and the second hour and standard deviation σ _h2/d1 ; ...; the average value of the relative value of the residual current until the 1st day and the 24th hour

and standard deviation σ _h24/d1 ;

B3. Obtain the standard deviation σ _d1 of all residual current relative values within 24 hours on the first day;

和标准差σ_h1/d2；获得第2天第2小时的剩余电流相对值的平均值

和标准差σ_h2/d2；……；直到第2天第24小时的剩余电流相对值的平均值和标准差σ_h24/d2；C3. Obtain the average value of the relative value of residual current in the first hour of the second day

and standard deviation σ _h1/d2 ; obtain the average value of the relative value of the residual current at the 2nd hour on the 2nd day

and standard deviation σ _h2/d2 ; ...; the average value of the relative value of residual current until the 2nd day and 24th hour and standard deviation σ _h24/d2 ;

D3. Obtain the standard deviation σ _d2 of all residual current relative values within 24 hours on the second day; use the same method as A3-D3 to obtain relevant statistical parameters on the 3rd, 4th, 5th, and 6th days;

和标准差σ_h1/d7；获得第7天第2小时的剩余电流相对值的平均值

和标准差σ_h2/d7；……；直到第7第24小时的剩余电流相对值的平均值和标准差σ_h24/d7；E3. Obtain the average value of the relative value of the residual current in the 1st hour on the 7th day

and standard deviation σ _h1/d7 ; obtain the average value of the relative value of the residual current at the 2nd hour on the 7th day

and standard deviation σ _h2/d7 ; ...; the average value of the relative value of the residual current until the 7th and 24th hours and standard deviation σ _h24/d7 ;

F3. Obtain the standard deviation σ _d7 of all residual current relative values within 24 hours on the seventh day.

和标准差σ_h1/d1以及24小时内n_d个剩余电流相对值的标准差σ_d1的具体计算公式如下，其余公式依此类推，此处不再重复列出。Among them, the average value of the relative value of residual current in the first hour

The specific calculation formulas for the standard deviation σ _h1/d1 and the standard deviation σ _d1 of the relative values of n _d residual currents within 24 hours are as follows, and the rest of the formulas can be deduced in the same way, and will not be repeated here.

${\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{\mathrm{<span\; class="notranslate">\; R</span>}}}_{{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="RC\; h"\; filenames="H2009102598589E00041.png"\; state="\{\{state\}\}">RC</figure-callout></span><figure-callout\; id="1"\; label="RC\; h"\; filenames="H2009102598589E00041.png"\; state="\{\{state\}\}">\; </figure-callout>}}_{\mathrm{<span\; class="notranslate">\; </span>}}}<span\; class="notranslate">\; =</span>\frac{\underset{\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{{\mathrm{<span\; class="notranslate">\; no</span>}}_{\mathrm{<span\; class="notranslate">\; h</span>}}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}{\mathrm{<span\; class="notranslate">\; R</span>}}_{{\mathrm{<span\; class="notranslate">\; RC</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}}}{{\mathrm{<span\; class="notranslate">\; no</span>}}_{\mathrm{<span\; class="notranslate">\; h</span>}}}$

${\mathrm{<span\; class="notranslate">\; \&sigma;</span>}}_{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="h"\; filenames="H2009102598589E00041.png"\; state="\{\{state\}\}">h</figure-callout></span>}\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="d"\; filenames="H2009102598589E00041.png"\; state="\{\{state\}\}">d</figure-callout></span>}\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; =</span>\sqrt{\frac{\underset{\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{{\mathrm{<span\; class="notranslate">\; no</span>}}_{\mathrm{<span\; class="notranslate">\; h</span>}}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{{\mathrm{<span\; class="notranslate">\; RC</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}}<span\; class="notranslate">\; -</span>{\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{\mathrm{<span\; class="notranslate">\; R</span>}}}_{{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="RC\; h"\; filenames="H2009102598589E00041.png"\; state="\{\{state\}\}">RC</figure-callout></span><figure-callout\; id="1"\; label="RC\; h"\; filenames="H2009102598589E00041.png"\; state="\{\{state\}\}">\; </figure-callout>}}_{\mathrm{<span\; class="notranslate">\; </span>}}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}{{\mathrm{<span\; class="notranslate">\; no</span>}}_{\mathrm{<span\; class="notranslate">\; h</span>}}}}$

${\mathrm{<span\; class="notranslate">\; \&sigma;</span>}}_{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="d"\; filenames="H2009102598589E00041.png"\; state="\{\{state\}\}">d</figure-callout></span>}\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; =</span>\sqrt{\frac{\underset{\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{{\mathrm{<span\; class="notranslate">\; no</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{{\mathrm{<span\; class="notranslate">\; RC</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}}<span\; class="notranslate">\; -</span>{\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{\mathrm{<span\; class="notranslate">\; R</span>}}}_{{\mathrm{<span\; class="notranslate">\; RC</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; 1</span>}}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}{{\mathrm{<span\; class="notranslate">\; no</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}}}}$

In the formula:

n _h —— theoretically collect a set of data per hour (1 residual current and three-phase current) times;

n _d —— theoretically, the number of times to collect a set of data (1 residual current and three-phase current) in 24 hours a day;

——第1天第1个小时所有计算获得的剩余电流相对值的平均值；

- the average value of the relative values of residual current obtained from all calculations at the first hour on the first day;

——第1天24小时所有计算获得的剩余电流相对值的平均值；

- the average value of the relative values of residual current obtained by all calculations in 24 hours on the first day;

σ _h1/d1 ——Standard deviation of all calculated residual current relative values obtained in the first hour of the first day;

σ _d1 ——Standard deviation of all calculated residual current relative values in 24 hours on the first day.

(3) Dynamic adjustment process (Dynamic-Adjusting)

和σ_h1/d1)进行一致性比较(看看差别是否在一个范围内，如果是，则满足一致性要求)；A4, will ( and σ _h1/d2 ) and (

and σ _h1/d1 ) for consistency comparison (see if the difference is within a range, if yes, the consistency requirement is met);

If the consistency requirements are met, the first alarm threshold after the first hour on the second day is as follows:

${\mathrm{<span\; class="notranslate">\; A</span>}}_{{\mathrm{<span\; class="notranslate">\; RC</span>}}_{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; no</span>}}_{\mathrm{<span\; class="notranslate">\; h</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; 2</span>}}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{{\mathrm{<span\; class="notranslate">\; RC</span>}}_{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; no</span>}}_{\mathrm{<span\; class="notranslate">\; h</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="d"\; filenames="H2009102598589E00041.png"\; state="\{\{state\}\}">d</figure-callout></span>}\mathrm{<span\; class="notranslate">\; 1</span>}}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&sigma;</span>}}_{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="d"\; filenames="H2009102598589E00041.png"\; state="\{\{state\}\}">d</figure-callout></span>}\mathrm{<span\; class="notranslate">\; 1</span>}}$

If the consistency requirements are not met, the first alarm threshold after the first hour on the second day is as follows:

${\mathrm{<span\; class="notranslate">\; A</span>}}_{{\mathrm{<span\; class="notranslate">\; RC</span>}}_{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; no</span>}}_{\mathrm{<span\; class="notranslate">\; h</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; 2</span>}}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{{\mathrm{<span\; class="notranslate">\; RC</span>}}_{{\mathrm{<span\; class="notranslate">\; no</span>}}_{\mathrm{<span\; class="notranslate">\; h</span>}}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; 2</span>}}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&sigma;</span>}}_{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="d"\; filenames="H2009102598589E00041.png"\; state="\{\{state\}\}">d</figure-callout></span>}\mathrm{<span\; class="notranslate">\; 1</span>}}$

By analogy, all the alarm thresholds of the first hour of the second day are obtained;

和σ_h2/d2)与(

和σ_h2/d1)进行一致性比较，B4, will (

and σ _h2/d2 ) and (

and σ _h2/d1 ) for consistency comparison,

If the consistency requirements are met, the first alarm threshold after the second hour on the second day is as follows:

${\mathrm{<span\; class="notranslate">\; A</span>}}_{{\mathrm{<span\; class="notranslate">\; RC</span>}}_{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; no</span>}}_{\mathrm{<span\; class="notranslate">\; h</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; 2</span>}}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{{\mathrm{<span\; class="notranslate">\; RC</span>}}_{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; no</span>}}_{\mathrm{<span\; class="notranslate">\; h</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="d"\; filenames="H2009102598589E00041.png"\; state="\{\{state\}\}">d</figure-callout></span>}\mathrm{<span\; class="notranslate">\; 1</span>}}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&sigma;</span>}}_{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="d"\; filenames="H2009102598589E00041.png"\; state="\{\{state\}\}">d</figure-callout></span>}\mathrm{<span\; class="notranslate">\; 1</span>}}$

If the consistency requirements are not met, the first alarm threshold after the first hour on the second day is as follows:

${\mathrm{<span\; class="notranslate">\; A</span>}}_{{\mathrm{<span\; class="notranslate">\; RC</span>}}_{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; no</span>}}_{\mathrm{<span\; class="notranslate">\; h</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; 2</span>}}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{{\mathrm{<span\; class="notranslate">\; RC</span>}}_{{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; no</span>}}_{\mathrm{<span\; class="notranslate">\; h</span>}}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; 2</span>}}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&sigma;</span>}}_{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="d"\; filenames="H2009102598589E00041.png"\; state="\{\{state\}\}">d</figure-callout></span>}\mathrm{<span\; class="notranslate">\; 1</span>}}$

By analogy, all alarm thresholds of the 2nd hour of the 2nd day are obtained;

 …

By analogy, all alarm thresholds of the 24 hours on the second day are obtained;

C4. After the beginning of the 3rd day, the object of comparison of the average value and standard deviation becomes the data of the 2nd day; through the same method as a and b, all alarm thresholds in each hour of the 3rd-7th day are obtained;

和σ_h1/d8)分别与(

和σ_h1/d7)以及(

和σ_h1/d1)进行一致性比较；D4, enter the 8th day, will (

and σ _h1/d8 ) and (

and σ _h1/d7 ) and (

and σ _h1/d1 ) for consistency comparison;

和σ_h1/d8)与(

和σ_h1/d7)的一致性更好，则第8天第1小时后第1个报警阈值如下：if(

and σ _h1/d8 ) and (

and σ _h1/d7 ), the first alarm threshold after the 1st hour on the 8th day is as follows:

${\mathrm{<span\; class="notranslate">\; A</span>}}_{{\mathrm{<span\; class="notranslate">\; RC</span>}}_{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; no</span>}}_{\mathrm{<span\; class="notranslate">\; h</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; 8</span>}}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{{\mathrm{<span\; class="notranslate">\; RC</span>}}_{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; no</span>}}_{\mathrm{<span\; class="notranslate">\; h</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; 7</span>}}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&sigma;</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; 7</span>}}$

和σ_h1/d8)与(和σ_h1/d1)的一致性更好，则第8天第1小时后第1个报警阈值如下：if(

and σ _h1/d8 ) and ( and σ _h1/d1 ), the first alarm threshold after the 1st hour on the 8th day is as follows:

${\mathrm{<span\; class="notranslate">\; A</span>}}_{{\mathrm{<span\; class="notranslate">\; RC</span>}}_{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; no</span>}}_{\mathrm{<span\; class="notranslate">\; h</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; 8</span>}}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{{\mathrm{<span\; class="notranslate">\; RC</span>}}_{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; no</span>}}_{\mathrm{<span\; class="notranslate">\; h</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="d"\; filenames="H2009102598589E00041.png"\; state="\{\{state\}\}">d</figure-callout></span>}\mathrm{<span\; class="notranslate">\; 1</span>}}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&sigma;</span>}}_{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="d"\; filenames="H2009102598589E00041.png"\; state="\{\{state\}\}">d</figure-callout></span>}\mathrm{<span\; class="notranslate">\; 1</span>}}$

If both consistency is not good, the first alarm threshold after the 1st hour on the 8th day is as follows:

${\mathrm{<span\; class="notranslate">\; A</span>}}_{{\mathrm{<span\; class="notranslate">\; RC</span>}}_{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; no</span>}}_{\mathrm{<span\; class="notranslate">\; h</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; 8</span>}}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{{\mathrm{<span\; class="notranslate">\; RC</span>}}_{{\mathrm{<span\; class="notranslate">\; no</span>}}_{\mathrm{<span\; class="notranslate">\; h</span>}}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; 8</span>}}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&sigma;</span>}}_{\text{<span class="notranslate"> d7</span>}}$

By analogy, all alarm thresholds of the first hour on the eighth day are obtained;

The program must store at least 7 days and 1 hour of data, that is, 7n _d +n _h relative values of residual current, and then replace the earliest relative value of residual current each time a new relative value of residual current is obtained.

...

By analogy, all the alarm thresholds of the 8th day and the 2nd hour are obtained...; the cycle continues.

(4) Real-time alarm process (Real-time-Alarming):

If the calculated relative value of residual current is greater than the determined alarm threshold, stop updating the alarm threshold in real time and continue to judge whether the next relative value of residual current is greater than the alarm threshold. If three consecutive relative values of residual current are greater than the alarm threshold, an alarm will be issued.

If the value of the relative value of the residual current in the alarm threshold at the monitoring time point is less than the set value, and the relative value of the residual current at the monitoring time point is greater than the alarm threshold, then continue to update the alarm threshold; when N consecutive residual currents after the monitoring time point When the current relative values are greater than the alarm threshold, an alarm will be issued, otherwise no alarm will be issued. In this case, the situation of load switching is considered, and N is related to the sampling frequency of data and the length of the load switching process.

If the three-phase load currents at the monitoring moment are all zero or completely equal, the relative value of the residual current is no longer used as the alarm threshold, but the residual current value is used as the alarm judgment value. If the residual current value exceeds the set value, an alarm will be issued, otherwise Do not call the police.

After adopting the method of this embodiment, the alarm threshold changes with the change of the normal residual current, and the alarm principle is shown in FIG. 4 . It can be seen that the alarm threshold varies with the normal residual current, but the relative alarm sensitivity remains consistent. Fig. 5 is a detailed flowchart of the method of the embodiment of the present invention.

It should be declared that: the above specific implementation process is only used to illustrate the present invention, and is not used to limit the protection scope of the claims. In the above specific implementation process, the relative value and standard deviation of the residual current on which the alarm threshold is based can be based on one day, or half a day, or even one hour; the stored data can also be stored for a week, half a month, or even an hour. monthly data, etc. All the various modifications based on the idea of the present invention belong to the protection scope of the claims of the present invention.

Example 2:

This embodiment provides a residual current monitoring and alarm system and a detection controller, and FIG. 6 is a schematic diagram of the system of this embodiment. As shown in Figure 6, the system of this embodiment includes: a centralized controller, a bus isolator, a detection controller, a current detector and a residual current detector; the centralized controller is connected to the detection controller through the bus isolator; the detection controller is connected to The current detector and residual current detector.

Among them: the current detector in this embodiment is used to collect the three-phase load current; the residual current detector is used to collect the residual current; the detection controller is used to generate and store each relative values of residual current at each collection time point; perform statistical analysis on a plurality of relative values of residual current within a preset period of time, generate and store the statistical parameters of the plurality of relative values of residual current; The relative value of the residual current and the statistical parameters are used to generate an alarm threshold at the monitoring time point; and the residual current of the monitoring loop is monitored and alarmed according to the generated alarm threshold.

Referring again to Fig. 6, wherein: the bus isolator is used to isolate the failed bus part from the whole system when the bus fails, so as to ensure that other parts of the system can work normally; the current detector and the residual current detection The device is the current transformer, which is used to detect the A, B, C three-phase load current and residual current of the low-voltage power distribution system, and transmit the detected value to the detection controller; the centralized controller and the detection controller are residual current type The core component of the electrical fire monitoring system. There is no essential difference between the main circuit detection controller and the branch circuit detection controller, but because of the different installation locations, the main circuit detection controller is installed at the main distribution cabinet of the power distribution system, and the branch circuit detection controller is installed at the power distribution At the branch distribution box of the system. The centralized controller is similar to the centralized controller of the fire alarm system. It has the function of collecting all related equipment signals and remote control, and is the main platform for human-computer interaction and parameter setting. The detection controller receives current and residual current signals, judges whether to alarm, transmits the signal to the centralized controller through the bus, and executes the tripping function when necessary. The detection controllers of each loop work independently, and the detection controllers can implement the method of Embodiment 1.

FIG. 7 is a functional block diagram of the detection controller of this embodiment. As shown in Figure 7, the detection controller 70 includes: an acquisition processing unit 701, which is used to generate and store the relative value of the residual current at each acquisition time point according to the collected three-phase load current value and residual current value; the statistical analysis unit 702, configured to perform statistical analysis on multiple residual current relative values within a preset time period, and generate and store statistical parameters of the multiple residual current relative values; a threshold generating unit 703 is configured to store the relative values of residual currents according to the monitoring time point before The relative value of the residual current and the statistical parameters generate an alarm threshold at the monitoring time point; the monitoring and alarm unit 704 is configured to monitor and alarm the residual current of the monitoring loop according to the generated alarm threshold.

Optionally, the preset duration in this embodiment includes one day, and the statistical parameters include the standard deviation of multiple residual current relative values in one day; the threshold generating unit 703 in this embodiment includes (as shown in FIG. 8 ): the first generation The unit 801 is used to generate the alarm threshold at the corresponding monitoring time point of the day according to the relative value of the remaining current at multiple collection time points of the previous day and the standard deviation of the previous day; the second generation unit 802 is used to generate The relative value of the residual current and the standard deviation of the previous day generate the alarm threshold of the corresponding monitoring time point of the day; the third generation unit 803 is used to generate the relative value of the residual current at multiple acquisition time points on the same day last week and the relative value of the remaining current at the same day last week The standard deviation of the same day generates the alarm threshold at the corresponding monitoring time point of the day.

Optionally, the preset duration also includes a plurality of subdivision periods in one day, and the statistical parameters also include the average value and standard deviation of a plurality of residual current relative values in each subdivision period; the threshold generation unit 703 also includes ( As shown in FIG. 8 ): the determination unit 804 is configured to determine the relative value and standard deviation of the residual current used to generate the alarm threshold of the monitoring time point according to the statistical parameter characteristics of the subdivided period, and determine from the first generation One of the generating unit, the second generating unit and the third generating unit is selected to generate the alarm threshold.

Optionally, the monitoring alarm unit 704 is configured to stop updating the alarm threshold when the relative value of the residual current at the monitoring time point is greater than the alarm threshold, and continue to judge whether the relative value of the residual current at the next monitoring time point is greater than the alarm threshold , if n consecutive residual current relative values are greater than the alarm threshold, an alarm will be issued, where n is a positive integer.

Optionally, the alarm threshold in this embodiment is the sum of the relative value of the residual current and the standard deviation; or, the alarm threshold is the sum of the relative value of the residual current and the integer multiple of the standard deviation. Optionally, the relative value of the residual current in this embodiment is a ratio of the residual current value to the vector sum of the three-phase load currents.

The specific control principle of the detection controller in this embodiment has been described in detail in Embodiment 1, and will not be repeated in this embodiment.

The above embodiments are only used to illustrate the technical solutions of the embodiments of the present invention, and are not intended to limit them; although the embodiments of the present invention have been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: it can still understand the foregoing The technical solutions recorded in each embodiment are modified, or some of the technical features are replaced equivalently; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims (10)

1. a residual current monitoring alarm method is characterized in that, described method comprises:

Gather the three-phase load current value and the residual electricity flow valuve in monitored loop;

According to the load current value and the residual electricity flow valuve of gathering, generate and store the residual current relative value of each acquisition time point;

A plurality of residual current relative values in the default duration are carried out statistical study, generate and store the statistics parameter of described a plurality of residual current relative values;

According to the described residual current relative value and the described statistics parameter of storage before the time point of monitoring, generate the alarm threshold value of time point of monitoring;

According to the alarm threshold value that generates the residual current of described monitoring loop is carried out monitoring alarm.

2. method according to claim 1 is characterized in that, described default duration comprises one day, and described statistics parameter comprises the standard deviation of a plurality of residual current relative values in a day;

Described described residual current relative value and described standard deviation according to storage before the time point of monitoring, the alarm threshold value that generates the time point of monitoring comprises:

According to the previous day a plurality of acquisition time points the residual current relative value and the standard deviation of the previous day, generate the alarm threshold value of corresponding time point of monitoring on the same day; Perhaps

According to residual current relative value before the same day time point of monitoring and the standard deviation of the previous day, generate the alarm threshold value of corresponding time point of monitoring on the same day; Perhaps

According to last week a plurality of acquisition time points on the same day the residual current relative value and last week standard deviation on the same day, generate the alarm threshold value of corresponding time point of monitoring on the same day.

3. method according to claim 2 is characterized in that, described default duration also comprises intraday a plurality of segmentation period, and described statistics parameter also comprises the mean value and the standard deviation of a plurality of residual current relative values in each segmentation period;

Described method also comprises: according to the statistics parameter characteristic of described segmentation period, be identified for generating the residual current relative value and the standard deviation of the alarm threshold value of time point of monitoring.

4. method according to claim 2 is characterized in that, described alarm threshold value is described residual current relative value and described standard deviation sum; Perhaps, described alarm threshold value is the integral multiple sum of described residual current relative value and described standard deviation.

5. method according to claim 1 is characterized in that,

When with constantly residual electricity flow valuve with the vector sum of three-phase load electric current constantly when all non-vanishing, described residual current relative value be described with residual electricity flow valuve constantly with described with the moment the three-phase load current vector and ratio;

When non-vanishing with residual electricity flow valuve constantly, and when being zero with the vector sum of three-phase load electric current constantly, described residual current relative value be the residual electricity flow valuve with the moment;

When being zero with constantly residual electricity flow valuve and vector sum with three-phase load electric current constantly, described residual current relative value is zero.

6. method according to claim 1 is characterized in that, describedly according to the alarm threshold value that generates the residual current of described monitoring loop is carried out monitoring alarm and comprises:

If the residual current relative value of described time point of monitoring is greater than described alarm threshold value, then stop to upgrade alarm threshold value, continue to judge that whether the residual current relative value of next time point of monitoring is greater than alarm threshold value, if n residual current relative value is all greater than alarm threshold value continuously, then report to the police, wherein n is a positive integer.

7. method according to claim 4 is characterized in that, describedly according to the alarm threshold value that generates the residual current of described monitoring loop is carried out monitoring alarm and also comprises:

If the numerical value of residual current relative value part is less than setting numerical value in the alarm threshold value of time point of monitoring, and the residual current relative value of time point of monitoring then continues to upgrade alarm threshold value greater than alarm threshold value;

When N continuous after the time point of monitoring residual current relative value during, then report to the police, otherwise do not report to the police all greater than alarm threshold value.

8. method according to claim 5 is characterized in that, describedly according to the alarm threshold value that generates the residual current of described monitoring loop is carried out monitoring alarm and also comprises:

If the vector sum of time point of monitoring three-phase load electric current is zero, judge then whether the residual electricity flow valuve of this time point surpasses default alarm threshold value, if surpass then warning, otherwise do not report to the police.

9. a residual current monitoring warning system is characterized in that, described system comprises: Centralized Controller, buses isolator, detection controller, current probe and residual current detector; Described Centralized Controller connects by buses isolator surveys controller; Described detection controller connects described current probe and residual current detector;

Described current probe is used to gather the three-phase load electric current;

Described residual current detector is used to gather residual current;

Described detection controller is used for generating and storing the residual current relative value of each acquisition time point according to the load current value and the residual electricity flow valuve of gathering; A plurality of residual current relative values in the default duration are carried out statistical study, generate and store the statistics parameter of described a plurality of residual current relative values; According to the described residual current relative value and the described statistics parameter of storage before the time point of monitoring, generate the alarm threshold value of time point of monitoring; According to the alarm threshold value that generates the residual current of described monitoring loop is carried out monitoring alarm.

10. a detection controller is characterized in that, described detection controller comprises:

The acquisition process unit is used for generating and storing the residual current relative value of each acquisition time point according to the three-phase load current value and the residual electricity flow valuve of gathering;

Statistical analysis unit is used for a plurality of residual current relative values in the default duration are carried out statistical study, generates and stores the statistics parameter of described a plurality of residual current relative values;

The threshold value generation unit is used for described residual current relative value and described statistics parameter according to storage before the time point of monitoring, generates the alarm threshold value of time point of monitoring;

The monitoring alarm unit is used for according to the alarm threshold value that generates the residual current of described monitoring loop being carried out monitoring alarm.

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