CN110880753A - Platform area line loss correction method based on HPLC environment - Google Patents

Abstract

The invention discloses a method for correcting line loss in a station area based on HPLC environment, belonging to the field of power supply management. First, obtain the topology structure diagram of the low-voltage distribution network at the community level, user information, obtain the electrical quantity measured by the gateway table and the meter side of the user terminal, and the statistical value of the line loss in the station area; identify the parameters of each line segment in the distribution network at the community layer; User phase identification, floor line and each line segment parameter identification result of power distribution system at residential level, calculate line-by-line and phase-by-phase calculation of technical line loss in building floor and residential level respectively; discriminate the statistical value of line loss in station area; The abnormal points are identified, and the corresponding monthly power consumption of users, and then the monthly power supply and line loss of the station area are corrected. According to the obtained line loss calculation results, it finds the high-incidence link of line loss in the low-voltage station area, so that the line loss can be managed more effectively and the line loss in the low-voltage station area can be quickly reduced. It can be widely used in the field of operation management of power supply system.

Description

A method for correcting line loss in the station area based on HPLC

technical field

The invention belongs to the field of power supply operation management, and in particular relates to a loss reduction method for line loss in a low-voltage station area.

Background technique

In the power system, the station area usually refers to the power supply range or area of a (one) transformer.

Active power loss and electrical energy loss generated in the process of power grid transmission and distribution are collectively referred to as line loss.

The types of line loss can usually be divided into five categories: statistical line loss, theoretical line loss, management line loss, economic line loss and fixed line loss.

The low-voltage station area is the main link of the line loss.

However, under the current line loss refinement platform, the statistical value of line loss in the low-voltage station area can only be obtained by comparing the electricity supply and sales. Due to metering or communication failures, the statistical value is sometimes inaccurate; even if it is accurate, it is impossible to distinguish between technical line loss and management line loss, and it is impossible to grasp where the line loss mainly occurs, which makes the low-voltage station area lack of line loss control. effective means.

Most of the residential loads are three-level loads. The power supply is generally taken from the 10kV power supply circuit of the nearby 110~35/10kV regional substation, and then stepped down to 0.4kV through the 10kV distribution transformer in the community.

The low-voltage power distribution system of the community is divided into two links: the community and the building:

(1) Community level power distribution system: from the 0.4kV outlet of the community distribution transformer to the unit low-voltage power distribution room (for high-rise/small high-rise unit housing)/unit distribution box (for multi-storey unit housing). Usually TN-S or TN-C-S three-phase power supply, radial wiring.

(2) Power distribution system in the building: the link from the unit low-voltage power distribution room/unit power distribution box to the user's electricity meter. For unit-type high-rise residential buildings, a small low-voltage power distribution room is usually set up in the basement of the unit, and the power supply is divided into two power sources. feed. For multi-storey residences or villas, a floor-mounted weather box is usually set at an appropriate position in front of the building or a floor-mounted incoming line box is set at the entrance of the first floor of the unit as an intermediate power distribution point to supply power to each building or floor in a radial manner. Each unit usually provides three-phase power to facilitate three-phase load balancing. There are generally two forms of unit power distribution: the first one, the unit main switch, branch switches and each household metering meter are installed in the unit distribution box, and radial wiring is used from the unit distribution box to each household distribution box; As shown in Figure 1, the unit main switch is installed in the unit distribution box, and the trunk-type wiring is used from the unit distribution box to the floor distribution box. Electric switch, from the floor distribution box to each household, adopts radial distribution. With the increase in the scale of residential electricity consumption, the latter wiring method is more common at present.

At present, high-speed power line carrier (high-speed power line carrier, HPLC) electricity information collection technology is becoming more and more mature. Through HPLC and smart meters, the power outage time can be reported in time, and the voltage, current and power of the low-voltage user's metering point every 5 minutes can be returned, and the station area identification and phase identification of the low-voltage user can be implemented. These functions provide new conditions for mastering the topology of the low-voltage distribution network, and then accurately analyzing the line loss in the low-voltage station area and carrying out the line loss management in the low-voltage station area.

Based on the above situation, in terms of power supply management and energy management, it is urgent to build a low-voltage station line loss analysis and management method suitable for the new acquisition environment, so as to quickly improve the operation efficiency of the low-voltage link.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to provide a method for correcting the line loss in the platform area based on the HPLC environment. It uses the phase-by-phase voltage, current and power data at the floor collector in the HPLC system and the user's electricity meter, and proposes a low-voltage distribution network structure tomography and line parameter analysis method for the floor line in the doorway and the two floors of the residential power distribution system. Then, using the obtained line parameters, the line-by-line line-by-phase line loss calculation is carried out on the building floor and the residential floor respectively, and the separation value of the technical line loss and the management line loss of the residential power distribution system is obtained. Then, according to the obtained line length, line-by-line load current and line loss calculation results of each link, find the high-incidence link of line loss in the low-voltage station area, so that the line loss can be more effectively managed and the line loss in the low-voltage station area can be quickly reduced.

The technical scheme of the present invention is to provide a method for correcting line loss in the platform area based on HPLC environment, characterized in that:

1) Obtain the topology diagram of the low-voltage distribution network community layer from the PMS; obtain the user information from the CIS; obtain the electrical quantity measured by the gateway meter and the user terminal meter side from the HPLC system; obtain the line loss of the station area from the line loss refinement platform Statistics;

2) Identify the parameters of each line segment in the distribution network at the community level;

3) According to the identification results of the user phase identification, floor line and each line segment parameter of the power distribution system at the community layer, calculate the line-by-line and phase-by-phase calculation of the technical line losses of the building floor and the community layer respectively;

4) Distinguish the statistical value of line loss in the station area;

5) Identify the abnormal points of the data, and correct the monthly power consumption of the corresponding users, and then the monthly power supply and line loss of the station area.

Wherein, the line-by-line and phase-by-phase calculation includes neutral line loss calculation, so that the calculation result is more in line with the actual technical loss in the station area.

Further, the determination of the statistical value of the line loss in the station area includes the line loss analysis of the cell distribution network phase-by-phase line-by-line technique and the line-loss analysis of the floor line phase-by-phase line technique.

Specifically, the phase-by-phase-by-wire technology line loss analysis of the cell distribution network includes:

Step 1: Obtain the split-phase current of each door opening;

Step 2: Calculate the current on each line segment in the platform area from the door opening current;

Step 3: From the current on the line segment, the technical line loss of each segment in the t period of the station area cell layer can be further obtained;

Step 4: Calculate the three-phase average current and the three-phase current unbalance of each door opening;

Step 5: Calculate the neutral loss of each door opening;

Step 6: First, calculate the sum of the split-phase currents flowing into each door and hole, so as to obtain the three-phase average current and the three-phase current unbalance degree of the community layer;

Step 7: Calculate the neutral loss of the cell layer.

Specifically, the floor line-by-phase-by-line technical line loss analysis includes:

Step 1: Obtain the current value transmitted on the floor line at each time period;

Step 2: According to the above calculation results of the resistance and reactance of each section of the floor line, combined with the current transmitted on it, calculate the line loss of each section of the phase-splitting technology;

Step 3: Calculate the three-phase current unbalance of each layer;

The fourth step: according to the current value of the users of each layer and the identification results of the aforementioned user phases, obtain the neutral line current of each layer;

Step 5: Calculate the neutral line loss of each layer in the door opening.

Specifically, the judging of the statistical value of the line loss in the station area includes the positioning of the three-phase unbalanced door opening, the line positioning of the unbalanced load, the judgment of whether the power supply radius conforms to the specification, and the rationality analysis of the line shape.

Further, the identification of abnormal data points includes the identification of abnormal measured values of electricity consumption and the correction of line loss in the station area, the detection of electricity theft, the correction of line loss in the station area, and the correction of electricity sales and line loss in the station area. .

Compared with the prior art, the advantages of the present invention are:

1. The technical scheme of the present invention realizes the analysis of the wiring mode and line parameters of the low-voltage distribution network by using the measurement data, thereby providing a basis for the calculation of technical losses in the platform area;

2. Based on the platform structure and parameter tomography results, it is possible to realize the line-by-line and phase-by-phase technical line loss analysis in the low-voltage platform region, as well as the separation of the technical line loss and the management line loss, and find the high-incidence link of the line loss in the low-voltage platform region. Effectively manage line losses and quickly reduce line losses in low-voltage platforms, thereby promoting refined management of line losses in low-voltage platforms;

3. For the time series analysis based on the voltage, current, power, and power factor of the user side, a search method for suspicious users of electricity stealing based on the horizontal migration of the time series of electrical quantities can be constructed to improve the timeliness of anti-stealing electricity, and at the same time, it can also estimate Type of electricity theft;

4. Based on the line length, line-by-line and phase-by-phase line loss analysis results, it is possible to further measure and analyze the distribution network construction and operation indicators such as the radius of the low-voltage power supply and the three-phase load balance of the doorway. The means of reducing loss are promoted and applied to the low-voltage distribution network to promote the loss-reduction and energy-saving of the low-voltage distribution network.

Description of drawings

Fig. 1 is a schematic diagram of a low-voltage power distribution system in a typical residential building;

Fig. 2 is the identification flow schematic diagram of the problem of line loss management in the stage area under the HPLC environment of the present invention;

FIG. 3 is a schematic diagram of a search process flow for suspicious users of electricity stealing based on HPLC electrical quantity level migration determination according to the present invention.

Detailed ways

The present invention will be further described below with reference to the accompanying drawings.

At present, high-speed power line carrier (high-speed power line carrier, HPLC) electricity information collection technology is becoming more and more mature. Through HPLC and smart meters, the power outage time can be reported in time, and the voltage, current and power of the low-voltage user's metering point every 5 minutes can be returned, and the station area identification and phase identification of the low-voltage user can be implemented. These functions provide new conditions for mastering the topology of the low-voltage distribution network, and then accurately analyzing the line loss in the low-voltage station area and carrying out the line loss management in the low-voltage station area.

The technical scheme of the present invention firstly uses the phase-separated voltage, current and power data at the floor collector in the HPLC system and the user's electricity meter to analyze the low-voltage distribution network structure and line parameters of the floor line in the doorway and the two floors of the residential power distribution system. Analysis; and then use the obtained line parameters to carry out line-by-line line-by-phase line loss calculation for the building floor and residential floor respectively, and obtain the separation value of the technical line loss and management line loss of the residential power distribution system; then, according to the obtained line length, According to the calculation results of line load current and line loss of each link, from the perspective of power supply radius, three-phase balance, rationality of wire selection, etc., find suitable technical loss reduction measures for the target station area; explore management loss reduction methods.

The technical scheme of the present invention provides a method for correcting the line loss in the platform area based on the HPLC environment, the invention of which is:

1) Obtain the topology diagram of the low-voltage distribution network community layer from the PMS; obtain the user information from the CIS; obtain the electrical quantity measured by the gateway meter and the user terminal meter side from the HPLC system; obtain the line loss of the station area from the line loss refinement platform Statistics;

2) Identify the parameters of each line segment in the distribution network at the community level;

3) According to the identification results of the user phase identification, floor line and each line segment parameter of the power distribution system at the community layer, calculate the line-by-line and phase-by-phase calculation of the technical line losses of the building floor and the community layer respectively;

4) Distinguish the statistical value of line loss in the station area;

5) Identify the abnormal points of the data, and correct the monthly power consumption of the corresponding users, and then the monthly power supply and line loss of the station area.

The technical solution is further described below:

A. Analysis of the power distribution network in the building:

HPLC collects the phase voltage, phase current, and electricity at the power receiving point of each user, as well as the phase voltage, phase current, and electricity at the floor collector, where the floor electricity is the sum of the electricity received by each phase of the user on the floor. Most of the residential users use single-phase power supply. The structural analysis of the distribution network in the building includes two aspects: the identification of the wiring mode of the split-phase low-voltage distribution lines and the identification of the parameters of the distribution lines of each phase.

The core problem of identifying the split-phase wiring in the building is to determine the phase to which each user belongs.

The phase identification method proposed in this technical solution is a data analysis method based on the user-side voltage, current, and electric quantity measurement signals, and the result can be used as a supplement to the identification result of the physical method; at the same time, the method is not limited to the physical identification method, because At present, the physical identification method for transmitting power line carrier signals only gives the phase of each user, and does not determine the sequence relationship between the users. tandem relationship.

A1. Phase identification:

记同时刻该层中第i个用户计量装置量得的相电压为U_f,i(t)，则用户相位辨识及同层用户间串接关系识别的流程为：In each layer, the in-phase users belong to the series connection relationship, and the load change of the downstream users will cause the same-direction change of the voltage of itself and all in-phase upstream and downstream users. Therefore, the correlation of voltage fluctuations of in-phase users on the same layer is significantly higher than that of non-in-phase users, and the closer the electrical distance between the two metering points, the greater the voltage correlation. According to the above principle, the s-phase voltage at time t collected by the f-th layer collector in the door hole is recorded as

Remember that the phase voltage measured by the i-th user metering device in the layer at the moment is U _f,i (t), then the process of user phase identification and identification of the tandem relationship between users in the same layer is:

Step 1: Calculate the correlation coefficient between the phase voltages of all users on the f-th floor and the phase voltages of the floor collectors, and record the correlation coefficient between the i-th user on the f-th floor and the s-phase voltage collected by the collector on this floor as γ _f,si .

Step 2: For each user belonging to the f-th layer, find the phase with the largest voltage correlation coefficient as the phase to which it belongs, that is, take the phase of the i-th user in the f-th layer

s _f,i =argmax{γ _f,si ; s∈{A,B,C}}

由大到小排序，相关系数较大的离采集器最近，由此确定同层同相用户间的串接关系。Step 3: According to the results of the previous step, the users who belong to the s-phase (s∈{A,B,C}) of the f-th layer are classified according to the in-phase voltage correlation coefficient collected by the collector and the collector.

Sorting from large to small, the one with the larger correlation coefficient is the closest to the collector, thereby determining the tandem relationship between the same-layer in-phase users.

Step 4: Repeat steps 1 to 3 for all floors f to determine the wiring mode of each phase (including the phase to which each user belongs and the serial connection relationship between users).

The user set of the f-th layer s-phase (s∈{A,B,C}) is denoted below as Ω _f,s .

A2. Floor line parameter identification:

In view of the fact that the metering devices of users on the same floor are placed in the same meter box and the distance is very close, the distance and loss of this part of the line are ignored. Therefore, the content of floor line parameter identification includes: ① the length of the line segment between the floor collectors; ② the impedance of the line segment between the floor collectors.

对应的电阻为

电抗为

记时段t采集的第f层采集器处的s相(s∈{A,B,C})电压为

记时段t第f至第f+1层的s相(s∈{A,B,C})楼层线上输送的电量为

则楼层线参数识别的流程如下：Suppose there is an F floor in the doorway, and the length of the floor line from the fth to the f+1th floor is recorded as

The corresponding resistance is

Reactance is

Denote the s-phase (s∈{A,B,C}) voltage at the f-th layer collector collected during period t as

Note that the electricity delivered on the floor line of the s-phase (s∈{A,B,C}) from the fth to the f+1th floor in the period t is:

The process of floor line parameter identification is as follows:

Step 1: Obtain the current value transmitted on the floor line at each time period. The current transmitted on a certain segment of the floor line is equal to the sum of the currents transmitted by all downstream users during the period, that is,

为第k层采集器量得的t时刻s相电流，它等于该时刻该层该相所有用户受电电流之和。In the above formula,

is the current of phase s at time t measured by the collector of the kth layer, which is equal to the sum of the currents received by all users in the phase of this layer at this time.

Step 2: Collect the voltages of each phase and each period collected at the floor collector, and calculate the voltage loss. Among them, the voltage loss on the s-phase floor line from the fth to the f+1th floor:

According to the second equation in the above equation, theoretically, the impedance of the floor line can be obtained by using the voltage and current values at one time. However, in view of the possible errors in the measurement values of voltage and current, the next fitting method is used to obtain the impedance of the floor line.

Step 3: For the floor line between two floors, construct the following minimization problem, and fit the impedance of the floor line between each floor in the doorway by solving the problem

A3. Analysis of the distribution network structure at the community level:

The wiring mode of the power distribution system at the community level can be checked in the PMS system, so the key point of the structural analysis is to determine the length of each line segment and the parameter values of resistance and reactance. The basic data for these parameter identification are only the voltage, current and power data collected at the 0.4kV outlet of the distribution transformer, and the end data is the voltage and current at the collector on the first floor in the doorway. In addition, the learned floor line impedance can be used to calculate The loss of the floor line in the doorway, and then inversely deduce the power supply at the collector on the first floor in the doorway. Based on the above data, this technical solution proposes a line loss comparison method to realize the identification of the parameters of each line segment in the power distribution network at the community level.

The flow of this method is as follows:

该值由门洞内所有用户t时段的受电量与门洞内t时段的电量损耗值相加获得；②各门洞的分相电流，对第k个门洞第s相t时刻的电流记为

它是该门洞该相所有用户在t时刻电流之和；③配电变压器0.4kV侧t时段的供电量E^T(t)。由Step 1: Obtain the original data, including: ① Obtain the power received at the collector on the first floor in the doorway, that is, the total power supply of the entire doorway, and record the mth doorway as

This value is obtained by adding the power received by all users in the doorway in the t period and the power consumption value in the doorway in the t period; ② the split-phase current of each door hole, the current of the kth door hole at the s-th phase at time t is recorded as

It is the sum of the currents of all users in the door and the phase at time t; ③ the power supply E ^T (t) of the 0.4kV side of the distribution transformer in the period t. Depend on

The total technical loss of the distribution network link of the cell in the station area during the t period can be obtained (where M represents the set of door openings in the station area).

The second step: construct the downstream node identification matrix Γ according to the community distribution network structure. Among them, the elements in the downstream node identification matrix take the value according to the following formula

The third step: Calculate the current on each line segment in the platform area from the door-hole current. Since the distribution network of the community is a radial connection, each node corresponds to a branch upstream, so the current of the branch corresponding to the node can be represented by the injected current of the node. Furthermore, the current of the s-th phase at time t can be calculated as follows:

为台区中小区层第s相各线段上t时刻的电流组成的向量；

为台区中各节点第s相t时刻注入电流构成的向量，仅当节点为末端节点时(即门洞配电箱处)，注入电流等于流入门洞的相电流，否则为零。In the above formula: n is the number of nodes at the cell layer within the station area;

is the vector composed of the currents at time t on each line segment of the s-th phase in the cell layer in the platform area;

is the vector formed by the injected current at the s-th phase t of each node in the platform area. Only when the node is the end node (ie, at the doorway distribution box), the injected current is equal to the phase current flowing into the doorway, otherwise it is zero.

From the current on the line segment, it can be further written that the theoretical value of the total loss in the stage t period of the cell layer is:

Step 4: Obtain the resistance value of each line segment through the problem of minimizing the deviation between the theoretical value and the measured value of the loss in each period of the community layer (as follows):

该向量维数等于小区节点数，仅当第i节点为末端门洞节点时对应元素非零。这样，据分叉节点引出的通路l∈L_k可算得的分叉点k的第s相t时刻电压可按下式计算：Step 5: In order to further obtain the branch impedance, and then obtain the branch reactance and line length, count the bifurcated nodes in the cell (that is, there are at least two nodes downstream of the node, and the bifurcated nodes include the distribution transformer exit node, that is, the number is 0 node), denoted as set N _C ; define a path set L _k for each bifurcation node k∈N _C , each element in the set corresponds to a path from the node to the end door node; and, for each For a path l∈L _k , denote all nodes belonging to the path but not including the first node of the path as set N _l ; define the voltage vector of the s-th phase t moment of the end node of the cell

The dimension of this vector is equal to the number of nodes in the cell, and the corresponding element is non-zero only when the i-th node is the terminal door node. In this way, the voltage at the s-th phase t of the bifurcation point _k can be calculated according to the path l∈Lk drawn from the bifurcation node can be calculated as follows:

为仅第j个元素为1、其余元素为零的列向量；Z_j为小区内以第j个节点为尾节点的线段的阻抗。In the above formula,

is a column vector with only the jth element being 1 and the rest being zero; Z _j is the impedance of the line segment with the jth node as the tail node in the cell.

Step 6: Construct the following optimization problem, and fit the impedance Z _j of each line segment that satisfies the following optimization objectives

The above formula indicates that the impedance of each line segment in the cell layer should make the voltages calculated by each bifurcation node according to its various paths approximately equal.

Step 7: Calculate the reactance X _j of the line segment j from Z _j and R _j , the calculation formula is:

Step 8: Calculate the unit length resistance, reactance value and corresponding line type of each line segment. The method is to first find the impedance angle of the wire, and the calculation formula for the impedance angle of the jth line segment is:

Compare the result of the above formula with the impedance angle of each 0.4kV cable, and find the closest line type, which is the line type of the line, and denote the corresponding unit length resistance and reactance as r _l and x _l respectively, then by

l _l =R _l /r _l

or l _l =X _l /x _l

The length of this line segment can be determined.

In the previous centralized reading environment, only the statistical value of the line loss in the low-voltage station area can be obtained through the comparison of electricity supply and sales, and it is impossible to subdivide the technical line loss and management line loss, and it is impossible to subdivide the occurrence of the technical line loss. .

Under the HPLC acquisition environment, the topology results and line parameters of the low-voltage distribution network can be separated out, which provides the possibility to calculate the technical line loss according to the load data; by deducting the calculated value of the technical line loss from the line loss statistical value, you can further know the management of the station area Line loss; in addition, the line-by-line and phase-by-phase loss can be clearly defined in the technical line loss analysis, which provides a basis for the refined management of line loss in the low-voltage station area.

B. Calculation method of line-by-line and phase-by-phase technology in Taiwan area:

According to the identification results of the user phase identification, floor line and each line segment parameter of the power distribution system at the community layer, the technical line loss of the building floor and the community layer can be calculated line by line and phase by phase to realize the refined analysis of the line loss. The technical line loss calculation method in the station area involved in this technical solution is different from the traditional theoretical line loss calculation method: on the one hand, the method proposed in this technical solution implements line-by-line and phase-by-phase calculation; on the other hand, considering that The problem of unbalanced three-phase load in the low-voltage power distribution system is more prominent. The method constructed in this technical solution includes the calculation of neutral line loss, which can make the calculation result more in line with the actual technical loss in the station area.

B1. Calculation of technical line loss of floor line phase-by-phase line-by-line:

(f＝1,…,f-1)，则楼层线逐线损耗的计算流程如下：Suppose there is an F floor in the doorway, and the resistance and reactance of the floor lines from the fth to the f+1th floor are respectively

(f=1,...,f-1), then the calculation process of the line-by-line loss of the floor line is as follows:

Step 1: Obtain the current value transmitted on the floor line at each time period. The current transmitted on a certain segment of the floor line is equal to the sum of the currents of all downstream users during the period, that is,

为第f至第f+1层s相楼层线上t时刻的电流；I_k,i(t)为第k层第i个用户t时刻的电流；Ω_f,s是第f层s相的用户集合。In the above formula,

is the current at time t on the s-phase floor line from the fth to the f+1th floor; I _k,i (t) is the current at the ith user at the kth floor at time t; Ω _f,s is the s-phase current on the fth floor User collection.

The second step: According to the above calculation results of the resistance and reactance of each section of the floor line, combined with the current transmitted on it, calculate the line loss of each section of the phase-splitting technology. For the technical line loss on the s-phase floor line from the fth to the f+1st floor in the period t, the calculation formula is as follows:

Step 3: Calculate the three-phase current unbalance of each layer. First, according to the user current value of each layer of the door opening and the identification result of the aforementioned user phase, the phase-splitting current value of each layer is calculated, and then the average value of the three-phase current of each layer is calculated, and the three-phase current imbalance degree of each layer is obtained. The formulas for obtaining the split-phase current, the average value of the three-phase current and the unbalance degree of the three-phase current in the f-th layer of the period t are as follows:

Obviously, for the three-phase current unbalance, we have

Step 4: According to the current values of users in each layer and the identification results of the aforementioned user phases, obtain the neutral line current of each layer, and the formula for obtaining the neutral line current of the f-th layer in the period t is as follows

则有remember

then there are

有Expressed by three-phase current unbalance

Have

Step 5: Calculate the neutral line loss of each layer in the door opening. According to the obtained neutral line current of layer f, set the neutral line resistance of layer f to be R _f,0 , then the loss of neutral line of layer f in period t is

B2. Calculation of line loss by phase-by-phase and line-by-line technology in residential distribution network:

According to the resistance and reactance values of each line segment of the power distribution system at the community layer obtained from the foregoing content, combined with the current value of the user's meter in each door, the technical line loss at the community layer can be calculated line by line and phase by phase.

The calculation process of technical line loss is as follows:

计算公式如下Step 1: Obtain the phase-splitting current of each door opening. This value is obtained by summing the current values of all users in the same phase in the door opening at time t. The current of the k-th door opening at the s-th phase at time t is recorded as

Calculated as follows

Step 2: Calculate the current on each line segment in the platform area from the door-hole current. The calculation formula for the current at time t of the s-th phase is:

为台区中小区层第s相各线段上t时刻的电流组成的向量；

为台区中各节点第s相t时刻注入电流构成的向量，仅当节点为末端节点时(即门洞处)，注入电流等于流入门洞的相电流，否则为零；n为台区内小区层节点数，针对小区层的树状结构，每条线段均可被其尾节点唯一地表示，因此

表示以节点l为尾节点的线段上的电流。In the above formula,

is the vector composed of the currents at time t on each line segment of the s-th phase in the cell layer in the platform area;

is the vector formed by the injected current at the sth phase of each node in the station area at time t. Only when the node is the end node (that is, at the door), the injected current is equal to the phase current flowing into the door, otherwise it is zero; n is the cell layer in the station area The number of nodes, for the tree structure of the cell layer, each line segment can be uniquely represented by its tail node, so

represents the current on the line segment with node l as the tail node.

Step 3: From the current on the line segment, the technical line loss of each segment in the stage t period can be further written.

In the above formula, τ is the time interval of current measurement.

Step 4: Calculate the three-phase average current and the three-phase current unbalance degree of each door opening. The calculation formula for the three-phase average current and the three-phase current unbalance degree at the time t of the kth door opening is:

Step 5: Calculate the neutral line loss of each door hole, set the neutral line resistance of the kth door hole as R _k,0 , then the calculation formula of the neutral line loss of the kth door hole at time t is:

Step 6: First, calculate the sum of the split-phase currents flowing into each door and hole, so as to obtain the three-phase average current and the three-phase current unbalance degree of the community layer. Assuming that there are K door openings in the community layer, the sum of the split-phase currents of each door opening is

Further calculate the three-phase average current and the three-phase current unbalance degree of the cell layer

Step 7: Set the neutral line resistance of the community layer as R ₀ , and calculate the neutral line loss of the community layer. The formula is as follows

B3. Calculation of management line loss in Taiwan area:

The calculated value of the technical line loss can be obtained by subtracting the calculated value of the technical line loss from the corrected statistical value of the line loss in the station area to obtain the value of the management line loss in the station area, that is,

In the above formula, _ΔEM represents the management line loss of the station area in the current month; E _T (t) is the calculated value of the technical line loss of the station area at time t, which is calculated by the following formula

表示t时段小区配电线路损耗；

表示t时段楼内配电线路损耗。In the above formula,

Indicates the loss of the distribution line in the community during the t period;

Indicates the loss of the distribution line in the building at time t.

C. Ways to reduce technical losses in the low-voltage platform area:

In the traditional acquisition environment, the three-phase unbalance can be analyzed for the low-voltage station area, but I don’t know how to balance the three-phase load; at the same time, because the current and loss on each line cannot be known, there is also a lack of other technologies that can analyze the station area. method of loss reduction measures. The HPLC acquisition environment provides the possibility for line parameter chromatography and line-by-phase line-by-phase line loss analysis in the station area, thereby enriching the means to analyze the technical loss reduction methods in the low-voltage station area, including:

(1) Positioning of three-phase unbalanced door openings: The three-phase unbalance degree of each door opening can be evaluated, and the door openings that need to be treated with three-phase unbalance can be located. For these door openings, the three-phase load balance can be optimized by the user's phase adjustment.

(2) Line positioning with unbalanced load: The lines drawn from the distribution transformers in the cell should balance the load rate as much as possible to avoid heavy load on some lines and light load on other lines. To this end, the load rate balance evaluation can be carried out on the load rate of the outgoing line of the station transformer, and the station area with unbalanced load between the lines can be found. For the completed station area, the load cutover between lines is relatively difficult, but the evaluation results can be used as the basis for evaluating the quality of the project and as a reference for subsequent similar residential wiring projects.

(3) Judgment of whether the power supply radius complies with the specification: The "Regulations on Several Technical Principles of Power Grids" stipulates that the low-voltage power supply radius is ≤150m, but the low-voltage power supply radius cannot be measured and analyzed in the traditional acquisition environment. According to the results of the distribution network tomography in the second chapter, the lengths of the line segments of the community floor and the building floor have been obtained, so that the maximum power supply radius of the community can be calculated and analyzed, and then it can be judged whether it meets the requirements of the technical principles. The unreasonable power supply radius is mainly caused by the unreasonable location of the substation and the unreasonable wiring of the community. For the completed community, it is not feasible to shorten the power supply radius. refer to.

(4) Rationality analysis of line type: Check whether there are perennial heavy-load or light-load lines in the distribution lines of the community and the distribution lines in the building. If replacing other line types helps to reduce losses, it means that there are line types in the station area. Unreasonable question.

C1. Analysis of load imbalance between door openings:

The phase-to-phase load unbalance degree of the door opening can be measured by the three-phase current unbalance degree of the door opening. For the kth door opening, the three-phase current unbalance degree calculation formula is:

与

分别是t时刻第k个门洞口三相中最大、最小的相电流，即in the formula

and

are the maximum and minimum phase currents in the three phases of the kth door opening at time t, namely

与

为t时刻第k个门洞内第

相各用户的电流之和。in

and

is the kth door in the kth door at time t

The sum of the currents of each user of the phase.

The relevant regulations of the power system stipulate that the three-phase load unbalance of the main line and the main branch line shall not exceed 20%. Since the three-phase balance of the doorway directly affects the three-phase balance of the main line and each branch line, this criterion is extended to the doorway. If the phase current unbalance degree is greater than 20%, it is judged as unreasonable, that is, the three-phase load balance is regarded as a technical loss reduction measure to be considered for one phase of the corresponding door opening and corresponding platform area.

相电流不平衡度if defined

Phase current unbalance

Among them: I _φ is the current of each phase, φ={A, B, C}; I _av is the three-phase average current. Then the calculation formula of power loss considering the unbalanced three-phase load is as follows:

In the low-voltage power grid, the cross-section of the neutral line is the same as that of the phase line, that is, R ₀ =R, so the above formula can be simplified as

三相负荷不平衡度增大时线路损耗会增加，不平衡度越大则线路损耗越大。同时可得三相负荷不平衡情况下的线损修正系数It can be seen from the above formula that β _A = β _B = β _C = 0 when the three-phase load is balanced, and the line loss ΔP is the smallest at this time, which is

When the unbalance degree of the three-phase load increases, the line loss will increase, and the greater the unbalance degree, the greater the line loss. At the same time, the line loss correction coefficient under the condition of three-phase load unbalance can be obtained

The above formula can be used to evaluate the drop value of each door opening and then the line loss in the platform area after correcting the three-phase load imbalance problem.

C2. Analysis of load imbalance between lines:

The load of the distribution line should be as balanced as possible to avoid heavy load on some lines and light load on some lines. However, considering the layout of door openings in the cell, load balance between lines can only be considered between adjacent lines. To this end, the load unbalance degree between the distribution network lines in the community is defined as the maximum value of the maximum and minimum power percentage deviations between adjacent lines in the distribution system of the community within a certain period of time, that is,

与

分别是第σ组邻近线路t时刻在变压器出口处的传输功率的最大值和最小值。其中，变压器出线传输功率可在已知门洞第一层采集器处供电量的情况下，通过末端功率加上线路损耗的方法逐级倒推得到。In the formula: Θ is the set of adjacent lines in the cell;

and

are the maximum and minimum values of the transmission power at the transformer outlet at the time t of the σ-th group of adjacent lines, respectively. Among them, the transmission power of the transformer outlet can be obtained by step by step backward by adding the end power and the line loss when the power supply at the collector on the first layer of the door is known.

Since the load balance between lines is related to the distribution of users in the community and the electricity consumption habits of users in each doorway, the load balance between lines can only be used as a reference in the analysis of unreasonable line losses in low-voltage station areas, and it is difficult to further Load balance between lines is achieved through load cutover between lines.

C3. Reasonability analysis of power supply radius:

The power supply radius usually refers to the straight-line distance between the substation and the farthest load point it supplies, but the low-voltage power supply radius generally refers to the line length from the power point to the farthest load it supplies, rather than the spatial distance.

According to the length of the line segment of the cell layer obtained above, the maximum power supply radius of the cell can be calculated and analyzed. To this end, it is necessary to first calculate the length of the line from the distribution of the cell to each door (hereinafter referred to as a path), and its maximum value is the maximum power supply radius of the cell.

According to the line lengths of each line segment at the cell layer calculated earlier, the length vector L ^XQ of the distribution line is constructed, that is,

如下In the formula, l _i represents the line length of the line segment with the i-th node as the tail node, where l ₁ =0. According to the downstream node identification matrix Γ constructed in Chapter 2, the power supply radius vector of each node can be further calculated

as follows

代表第i个节点距离配变出口的线路总长，当i为门洞节点时

即为一条通路的长度。In the node supply radius vector,

Represents the total length of the line from the i-th node to the outlet of the distribution transformer, when i is a doorway node

is the length of a path.

Then calculate the sum of the line lengths of the floors in each door opening. The maximum length vector of the floor line of the door opening is recorded as

代表第i个节点所对应门洞的楼层线最大长度，若第i个节点不对应门洞，则

否则按如下公式计算in the formula

Represents the maximum length of the floor line of the door opening corresponding to the ith node. If the ith node does not correspond to the door opening, then

Otherwise, it is calculated according to the following formula

为第i个节点所对应门洞的f层至f+1层楼层线线长。in the formula

is the line length of the floor line from floor f to floor f+1 of the door opening corresponding to the ith node.

Finally, the maximum power supply radius of the cell is obtained, that is,

是否超过150m，若超过，则说明该小区线长不合理。According to the technical principle, the radius of the low-voltage power supply should not exceed 150m.

Whether it exceeds 150m, if it exceeds, it means that the line length of the cell is unreasonable.

D. Management line loss identification process under HPLC environment:

The process of analyzing the management line loss problem in the station area is shown in Figure 2:

(1) Obtaining the management line loss value: Use the aforementioned correction of abnormal values in the line loss statistics of the station area, and at the same time adopt the calculation and analysis of the line loss of the implementation station area technology, and then subtract the station area line loss statistical value from the station area at the same period. The technical line loss, that is, the management line loss in the Taiwan area.

(2) Power consumption abnormal value identification and line loss correction: Identify abnormal data points, and correct the corresponding monthly power consumption of users, and then the monthly power supply and line loss of the station area.

(3) Investigation of electricity theft in the station area: find out the users suspected of stealing electricity in the station area, make an estimate of the electricity stealing, and then correct the power supply and line loss in the station area.

D1. Identification of abnormal measured value of electricity consumption and correction of line loss in station area:

In the HPLC environment, there are two main phenomena of abnormal user power consumption data collection: one is the signal crosstalk caused by the carrier communication failure, that is, when the meter is copied to a meter with a similar address, the meter skips words, which is manifested as a step change in the metering data. ; The second is data defects caused by meter chip defects, such as the lack of current and electricity. Since the first problem only affects the accuracy of electricity bills and electricity charges, but does not affect the electricity sales and line loss statistics in the Taiwan area, this project only studies the identification of the second problem and the corresponding line loss correction in the Taiwan area. .

After analyzing the user-side data collected by HPLC, it was found that the data caused by the defect of the meter chip often showed that there was current and voltage but no power, including two cases where the power was zero in some periods and zero in all periods. These zero-power situations must be distinguished from zero-power situations resulting from power theft by users.

For this reason, denote I _k (t), U _k (t), and P _k (t) as the current, voltage, and power values measured at the k-th user metering point at time t, respectively, then if part of the time period satisfies:

I _k (t)>0 and U _k (t)>0 and P _k (t)=0

It can be determined that the data abnormality is caused by the problem of the meter; if the current is non-zero and the power is zero continuously, it may be a problem of the meter or electricity theft. Confirmed after manual inspection.

For users who meet the above conditions, the following formula is used to implement the correction of the power consumption at time t:

为该时刻第k个用户用于有功功率矫正的功率因数，可取该用户用电功率量测值非零的时刻中最接近t时刻的功率因数值。In the above formula, P _k '(t) is the corrected electric power value of the kth user at time t;

For the power factor used for active power correction of the kth user at this time, the power factor value closest to time t in the time when the measured value of the user's electric power is non-zero can be taken.

After correcting the power value at the user's metering point, the monthly electricity sales in the station area is calculated as follows

Then, calculate the line loss correction value in the station area as follows:

ΔE=E ^G -E ^S '

D2. Electricity theft investigation and line damage correction in the station area:

The purpose of the electricity theft investigation is to find out the users who are suspected of stealing electricity in the Taiwan area.

The solution to this problem in the HPLC acquisition environment has two characteristics:

①It can be judged by using the measured values of voltage, current and electricity to identify suspicious users of electricity stealing, and can also judge the type of electricity stealing according to the combined relationship between multiple quantities;

②Because one point is collected every 5 minutes, the start and end time of electricity stealing can be determined more accurately, so as to make more accurate corrections for electricity sales and line loss in the station area.

(1) Search method for suspicious users of electricity stealing:

The combined appearance of the user-side measurement data under different power stealing methods is different: the loss of voltage/undervoltage method leads to a sudden drop in voltage, which in turn leads to a decrease in active power metering value and accumulated power consumption; loss of current/undervoltage The current method leads to a sudden drop in current, which in turn leads to a drop in the active power metering value and cumulative power consumption; the phase-shift method causes a sudden drop in the power factor, which in turn leads to a drop in the active power metering value and cumulative power consumption. The power factor is not directly displayed. However, the relationship between the active power metering value and the product of voltage and current can be investigated; the changes of voltage, current and power factor under other electricity stealing methods are more complicated, and the combination is not single, but all will cause active power, and further Sudden drop in power consumption.

No matter which method of stealing electricity will always cause a sudden drop in a certain electrical quantity (such as voltage, current, power factor, active power),

D3. Search method for suspicious users of electricity stealing based on HPLC electrical quantity level migration judgment:

Assume that the time series of electrical collection quantities to be investigated by user k are x ₁ , _{x 2} , . , power factor (for the phase-shift method), and daily electricity consumption (for other possible electricity stealing methods), then each user judges whether to classify it as a suspected electricity stealing user through the process shown in Figure 3.

The method detects the downward horizontal sudden drop point of the electrical quantity by continuously moving the window, and the fixed window sudden drop point detection of each step is implemented by the following steps:

The first step: find the cumulative sum value, the calculation formula is

S ₀ =0

为x₁x₂…x_n的均值，即in

is the mean of x ₁ x ₂ ... x _n , that is

Step 2: Find the maximum deviation of the cumulative sum value, the calculation formula is

Step 3: Calculate the cumulative sum value and its maximum deviation value for various permutations and combinations of the original time series;

计算累积和值

再计算累计和值的最大偏差值

Rearrange the time series x ₁ x ₂ ... x _n in random order, the number of such permutations should be n! -1, take 1000 of them for analysis. The jth permutation is recorded as

Calculate the cumulative sum value

Recalculate the maximum deviation of the accumulated sum value

如果是，则可能存在水平迁移，且该水平迁移的置信度为Step 4: Determine whether there is a certain permutation j such that

If yes, there may be horizontal migration, and the confidence level of this horizontal migration is

的次数；In the above formula, N is the number of experiments in which the original time series is randomly arranged in other order. If all the arrangements are traversed, then N=n! -1; α is in N experiments

the number of times;

Step 5: If the confidence level of the horizontal migration is greater than or equal to 95%, then further obtain the time when the Level Change occurs by calculating the original stationary time series.

Then the time m is the time when the mean value changes, and the time m+1 is the first time after the mean value changes;

If x _m <x _m +1, the horizontal migration is upward horizontal migration; if x _m >x _m +1, the horizontal migration is downward horizontal migration.

Only users who find the downward horizontal migration are judged as suspicious electricity stealing, and the upward horizontal migration time found after the electricity stealing start time can be used as the electricity stealing stop time.

D4. Correction of electricity sales and line loss in Taiwan:

和

(均为日期号，若非目标月开始/结束的窃电，这两个时间可能为月首第一天/月末最后一天)，该用户在窃电起始时间前的同月用电量为

则台区售电量按下式矫正Through the previous investigation of electricity theft, it has been possible to determine the start and end time of electricity theft while finding out the suspicious users of electricity theft. If the set of suspicious users of electricity stealing in the target platform area is set as Cs, the starting and ending times of the kth user's electricity stealing in the current month are respectively

and

(both date numbers, if it is not the start/end of the target month, the two times may be the first day of the month/the last day of the month), the electricity consumption of the user in the same month before the start time of electricity theft is:

Then the electricity sales in Taiwan area can be corrected according to the following formula

In the above formula, n _d is the total number of days in the target month, and ^ES and ^ES ' are the monthly electricity sales of the station area before and after correction, respectively. Furthermore, when the line loss in the platform area is corrected as follows:

ΔE=E ^G -E ^S '

D5. Analysis of loss reduction potential:

For the existing community, the unreasonable power supply radius is difficult to solve by relocation of the substation, and the load imbalance between lines is also subject to the load distribution, and the pilot station area does not have the problem of unreasonable line selection. Therefore, the loss reduction potential can only be tapped from the perspective of three-phase load balance of the door opening.

During the on-site testing process, the three-phase load cutover was implemented for the door openings with a three-phase current unbalance of more than 20%. Assuming that the three-phase load can be completely balanced, the line loss rate of the community dropped from 4.19% to 3.54% during the test phase. , which is a 0.65 percent drop.

According to this ratio, the measures of three-phase load balancing in the doorway can be extended to the residential area of the same type in the jurisdiction of a power supply company (according to 14,000 similar stations and the power supply is about 10 billion kWh/year), it can be passed through the doorway three The improvement of the phase balance reduces the loss by 65 million kWh/year, and increases the electricity fee income by 31.72 million yuan/year (calculated according to the average price of the first grade of 0.488 yuan/kWh).

The advantages of applying the HPLC power consumption information collection technology described in the technical solution of the present invention to the low-voltage line loss treatment method mainly include:

(1) The measurement data can be used to analyze the wiring mode and line parameters of the low-voltage distribution network, thereby providing a basis for the calculation of technical losses in the station area.

(2) Based on the platform structure and parameter tomography results, the line-by-line and phase-by-phase technical line loss analysis in the low-voltage platform area, as well as the separation of the technical line loss and the management line loss, can be found, and the high-incidence link of the low-voltage platform area line loss can be found. Manage line losses more effectively and quickly reduce line losses in low-voltage platforms.

(3) Analyze the time series based on the voltage, current, power, and power factor (the ratio of active power to the product of U and I) on the user side, and construct a new method for searching suspicious users of electricity stealing based on the determination of the horizontal migration of the time series of electrical quantities, so as to improve the anti-counterfeiting method. The timeliness of electricity theft and the type of electricity theft can also be estimated.

(4) Based on the line length and line-by-line line-by-phase line loss analysis results, it is possible to further calculate and analyze the distribution network construction and operation indicators such as the radius of the low-voltage power supply and the three-phase load balance of the doorway. The loss-reducing means of the low-voltage distribution network are promoted and applied to the low-voltage distribution network to promote the loss-reduction and energy-saving of the low-voltage distribution network.

The invention can be widely used in the field of operation management of the power supply system.

Claims (7)

1. A method for correcting the line loss of a transformer area based on an HPLC environment is characterized by comprising the following steps:

1) acquiring a low-voltage distribution network cell layer topology structure diagram from the PMS; acquiring user information from a CIS; acquiring electrical quantity measured by a gateway meter and a user terminal meter side from an HPLC system; acquiring a station area line loss statistic value from a line loss refinement platform;

2) identifying parameters of each line segment in a cell layer power distribution network;

3) according to the identification results of the user phase and the parameter identification results of each line segment of the power distribution system of the floor line and the cell layer, the technical line loss of the inner floor and the cell layer is calculated line by line and phase by phase respectively;

4) judging the line loss statistical value of the transformer area;

5) and identifying the data abnormal points, and correcting the monthly power consumption of the corresponding users and further the monthly power supply and the line loss of the transformer area.

2. The method of line loss correction for a distribution room in an HPLC environment as recited in claim 1, wherein said line-by-line and phase-by-phase calculations include neutral line loss calculations to make the calculation more consistent with the actual technical loss of the distribution room.

3. The method for correcting the line loss of the distribution room based on the HPLC environment as claimed in claim 1, wherein the step of discriminating the statistical value of the line loss of the distribution room comprises a phase-by-phase line-by-line technology line loss analysis of a distribution network of a cell and a phase-by-line technology line loss analysis of a floor line.

4. The method for correcting the line loss of the distribution room based on the HPLC environment as claimed in claim 3, wherein the line loss analysis of the phase-by-phase line-by-line technology of the distribution network of the cell comprises:

the first step is as follows: acquiring the split-phase current of each door opening;

the second step is that: calculating the current on each line section in the platform area according to the door opening current;

the third step: the technical line loss of each segment in the t period of the cell layer of the transformer area can be further obtained by the current on the line segment;

the fourth step: calculating the three-phase average current and the three-phase current unbalance degree of each door opening;

the fifth step: calculating the neutral line loss of each door opening;

and a sixth step: firstly, calculating the sum of split-phase currents flowing into each door opening, and thus obtaining the three-phase average current and the three-phase current unbalance degree of a cell layer;

the seventh step: and calculating the neutral line loss of the cell layer.

5. The HPLC environment-based line loss correction method for a distribution room as recited in claim 3, wherein the floor line phase-by-phase line-by-line technical line loss analysis comprises:

the first step is as follows: acquiring a current value transmitted on a floor line in each time interval;

the second step is that: according to the calculation results of the resistance and the reactance of each section of the floor line, the line loss of each section of the phase splitting technology is obtained by combining the current transmitted on the resistance and the reactance;

the third step: calculating the unbalance degree of the three-phase current of each layer;

the fourth step: obtaining neutral line current of each layer according to the current value of each layer of user and the identification result of the user phase;

the fifth step: and calculating the loss of the neutral line of each layer in the door opening.

6. The method for rectifying the line loss of the transformer area based on the HPLC environment according to claim 1, wherein the discrimination of the statistical values of the line loss of the transformer area comprises the positioning of a three-phase unbalanced door opening, the positioning of a line with unbalanced load, the judgment of whether the power supply radius meets the specification or not and the analysis of line type rationality.

7. The method for correcting line loss of distribution room based on HPLC environment as claimed in claim 1, wherein said identifying data anomaly points comprises identifying abnormal measurement values of power consumption and correcting line loss of distribution room, detecting electricity stealing and correcting line loss of distribution room and correcting electricity selling and line loss of distribution room.

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