Power distribution network state estimation method and system based on event triggering, terminal and medium

Abstract

The invention discloses a power distribution network state estimation method and system based on event triggering, a terminal and a medium, and the method comprises the steps: collecting a three-phase imbalance state quantity on a line switch of a three-phase imbalance power distribution network, describing a three-phase imbalance constraint of the three-phase imbalance state quantity, and constructing a three-phase imbalance measurement matrix based on the three-phase imbalance constraint; establishing a communication verification mechanism by using the three-phase imbalance measurement matrix, filtering a three-phase imbalance state quantity to be transmitted by using the communication verification mechanism, and transmitting a three-phase imbalance event to a state estimation server; in the state estimation server, reconstructing a three-phase imbalance estimator by using the received three-phase imbalance event, and constructing a power distribution network state estimation target in combination with a measurement error auxiliary matrix pre-generated in the state estimation server; and solving the state estimation target of the power distribution network to obtain a state estimation result of the power distribution network. According to the method, an excellent estimation effect is obtained while the communication pressure is relieved.

Description

Technical Field

[0001] The present invention relates to a field, and more specifically, to a distribution network state estimation method, system, terminal and medium based on event triggering. Background Art

[0002] In recent years, the widespread adoption of renewable energy and the increasing penetration of distributed power sources have brought significant uncertainty to the safe and stable operation of distribution networks. High-precision and timely distribution network state estimation is key to ensuring reliable operation. Traditional distribution networks primarily rely on limited Supervisory Control and Data Acquisition (SCADA) measurements. Consequently, insufficient redundancy in measurement information often hinders real-time state estimation.

[0003] With the development of advanced measurement systems in distribution networks, smart meter data provides a wealth of user information for distribution network state estimation. Therefore, combining smart meter measurement data with SCADA measurement data will effectively improve the redundancy of measurement information at the time of state estimation. However, the massive amount of smart meter data also places high communication pressure on the distribution network. One of the current challenges in building a distribution network situational awareness system is how to filter valid measurement data to reduce unnecessary real-time measurement uploads while achieving high-precision distribution network state awareness. In recent years, some researchers have introduced event-triggered mechanisms from the control field into distribution network state estimation. However, these studies limit the definition of events in event-triggered mechanisms to load fluctuations. However, topological changes in the distribution network can also cause changes in measurement information. Furthermore, the convergence and accuracy of real-time state calculations depend on the accuracy and real-time nature of the system topology data. Therefore, it is necessary to research real-time state identification technologies for distribution network switches to ensure the reliability of basic distribution network data and real-time calculations.

[0004] To address the above issues, there is an urgent need for a distribution network state estimation method, system, terminal and medium based on event triggering. Summary of the Invention

[0005] To address the deficiencies in the prior art, the present invention provides a distribution network state estimation method, system, terminal, and medium based on event triggering. By constructing a three-phase unbalance measurement matrix, a communication verification mechanism is adopted to extract unbalance events, and a state estimation server is used to comprehensively verify the three-phase unbalance state risk.

[0006] The present invention adopts the following technical solutions.

[0007] A first aspect of the present invention relates to a distribution network state estimation method based on event triggering, the method comprising the following steps: collecting three-phase unbalanced state quantities on line switches of a three-phase unbalanced distribution network, describing three-phase unbalanced constraints of the three-phase unbalanced state quantities, and constructing a three-phase unbalanced measurement matrix based on the three-phase unbalanced constraints; establishing a communication verification mechanism using the three-phase unbalanced measurement matrix, filtering the three-phase unbalanced state quantities to be transmitted using the communication verification mechanism, and transmitting three-phase unbalanced events to a state estimation server; in the state estimation server, reconstructing a three-phase unbalanced estimate using the received three-phase unbalanced event, and constructing a distribution network state estimation target in combination with a measurement error auxiliary matrix pre-generated in the state estimation server; and solving the distribution network state estimation target to obtain a state estimation result of the distribution network.

[0008] The three-phase unbalanced state quantities on the line switches of the three-phase unbalanced distribution network are collected, the three-phase unbalanced constraints of the three-phase unbalanced state quantities are described, and a three-phase unbalanced measurement matrix is ​​constructed based on the three-phase unbalanced constraints. The method includes: obtaining a topological connection relationship of the three-phase unbalanced distribution network based on the line switch positions and line connection relationships of the three-phase unbalanced distribution network; obtaining an association between the three-phase unbalanced state quantities on the line switches of the three-phase unbalanced distribution network based on the topological connection relationship of the three-phase unbalanced distribution network; constructing a three-phase unbalanced constraint based on the association; and constructing a three-phase unbalanced measurement matrix A with the numbers of the three-phase unbalanced constraint formulas as columns and the numbers of the three-phase unbalanced state quantities as rows.

[0009] The communication verification mechanism is established by using the three-phase unbalanced measurement matrix, including: constructing an event generation function based on the measurement device SCADA measurement device and the smart meter of the three-phase unbalanced distribution network:

[0010]

[0011] Where z t =[z s,t ] 1×n is the measurement of the measuring devices s = 1, 2, ..., n at the communication time t, where the measurement of the sth SCADA measuring device is (P s,ij ,Q s,ij );ij is the branch where the measuring device s is located, or the downstream branch; the amount of the s-th smart meter is (P s,k ,Q s,k ,V k ), k is the load node number where the smart meter is located, P, Q and V represent the active injected power, reactive injected power and voltage amplitude on the branch or node where the measuring device is located, respectively;

[0012] is the relevant state quantity of the current measuring device at the communication time t-1;

[0013] a mn is the element in the mth row and nth column of the three-phase unbalance measurement matrix; σ is the event threshold.

[0014] The communication verification mechanism is used to filter the three-phase unbalance state quantity to be transmitted, and the three-phase unbalance event is transmitted to the state estimation server, including: obtaining the event trigger logic variable γ of the sth measurement device according to the event generation function s,t ; If the event triggers the logical variable γ s,t =1, the three-phase unbalance event of the s-th measuring device is sent to the state estimation server.

[0015] Obtain the event trigger logic variable γ of the sth measurement device according to the event generation function s,t , including: If the event generates the result of the calculation function The event generation quantity g of the sth measurement device is s,t , greater than 0, a three-phase unbalance event is generated

[0016]

[0017] Where,

[0018] In the state estimation server, the three-phase imbalance event is used to reconstruct the three-phase imbalance estimation, including: setting the state transition amount of the three-phase imbalance event to be Based on the measurement error auxiliary matrix R pre-generated in the state estimation server, the three-phase unbalance objective function is constructed as follows:

[0019]

[0020] Based on the three-phase unbalance measurement matrix A, the three-phase unbalance constraint condition is constructed as follows:

[0021] X=v

[0022] AX=0

[0023] Where v is the random error vector.

[0024] The measurement error auxiliary matrix R is stored in the state estimation server during the last iteration and has

[0025] R=[cov(x s ,x s′ )] n×n

[0026] Where x s′ An element in the state transition quantity of another measurement device.

[0027] The distribution network state estimation target is constructed by combining the measurement error auxiliary matrix pre-generated in the state estimation server, including: the optimal solution of the three-phase unbalance objective function when the three-phase unbalance constraint condition is met is:

[0028]

[0029] Where λ=[λ1,λ2,…,λ i ,…λ N ], element λ i Calculated based on the random error vector v, where N is the number of parameters.

[0030] Solving the distribution network state estimation target to obtain the distribution network state estimation result includes: calculating the threshold value as:

[0031]

[0032] Where, v λ,ii is a diagonal matrix The i-th element of ;

[0033] C1 is the coefficient matrix.

[0034] A second aspect of the present invention relates to an event-triggered distribution network state estimation system, which is implemented using the event-triggered distribution network state estimation method described in the first aspect of the present invention. The system includes an acquisition module, a filtering module, a construction module, and an estimation module. The acquisition module is used to acquire three-phase unbalanced state quantities on line switches in a three-phase unbalanced distribution network, describe three-phase unbalanced constraints of the three-phase unbalanced state quantities, and construct a three-phase unbalanced measurement matrix based on the three-phase unbalanced constraints. The filtering module is used to establish a communication verification mechanism using the three-phase unbalanced measurement matrix, filter the three-phase unbalanced state quantities to be transmitted using the communication verification mechanism, and transmit three-phase unbalanced events to a state estimation server. The construction module is used to reconstruct a three-phase unbalanced estimate using the received three-phase unbalanced event in the state estimation server, and construct a distribution network state estimation target in combination with a measurement error auxiliary matrix pre-generated in the state estimation server. The estimation module is used to solve the distribution network state estimation target to obtain a state estimation result of the distribution network.

[0035] A third aspect of the present invention relates to a terminal, comprising a processor and a storage medium; the storage medium is used to store instructions; and the processor is used to operate according to the instructions to execute the steps of the method described in the first aspect of the present invention.

[0036] A fourth aspect of the present invention relates to a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the method described in the first aspect of the present invention.

[0037] The present invention offers the following advantages: compared to existing technologies, the event-triggered distribution network state estimation method, system, terminal, and medium described herein construct a three-phase imbalance measurement matrix, employ a communication verification mechanism to extract imbalance events, and utilize a state estimation server to comprehensively verify the three-phase imbalance state risk. This method achieves superior estimation results while alleviating communication pressure.

[0038] The beneficial effects of the present invention also include:

[0039] 1. To address the communication pressure on the distribution network caused by massive amounts of smart meter data, a closed-loop event trigger mechanism is introduced to reduce unnecessary measurement transmission. The definition of events in the event trigger mechanism is expanded from single load fluctuations to topology changes.

[0040] 2. Because the station switches lack telesignaling data and their status cannot be directly obtained, this invention uses triggered measurement information to establish a joint estimation model. Using a modified IEEE13 three-phase asymmetric system, the proposed method demonstrates that it can reduce communication pressure while achieving accurate estimation results and effectively identifying switch errors. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 A schematic diagram of three-phase unbalanced network quantity measurement and collection in a distribution network state estimation method based on event triggering according to the present invention;

[0042] Figure 2 A schematic diagram of an unbalanced network in an embodiment of a method for estimating a distribution network state based on event triggering according to the present invention;

[0043] Figure 3 This is an effect diagram of a communication filtering mechanism in a distribution network state estimation method based on event triggering according to the present invention;

[0044] Figure 4 An event triggering diagram in a distribution network state estimation method based on event triggering according to the present invention;

[0045] Figure 5 This is an example 1 of an estimation error diagram in a distribution network state estimation method based on event triggering according to the present invention;

[0046] Figure 6 This is Example 2 of an estimation error diagram in a distribution network state estimation method based on event triggering according to the present invention;

[0047] Figure 7A schematic diagram of communication parameters of a switch fault state in a distribution network state estimation method based on event triggering according to the present invention;

[0048] Figure 8 This is a schematic diagram of communication parameters after switch fault recovery in a distribution network state estimation method based on event triggering of the present invention. DETAILED DESCRIPTION

[0049] In order to make the purpose, technical solutions and advantages of the present invention clearer and more accurate, the technical solutions of the present invention are described in detail below through multiple specific embodiments. The embodiments used in the present invention are only used to explain the present invention and are not intended to limit the content of the present invention.

[0050] A first aspect of the present invention relates to a distribution network state estimation method based on event triggering, the method comprising steps 1 to 4.

[0051] Step 1: collect the three-phase unbalanced state quantity on the line switch of the three-phase unbalanced distribution network, describe the three-phase unbalanced constraints of the three-phase unbalanced state quantity, and construct a three-phase unbalanced measurement matrix based on the three-phase unbalanced constraints.

[0052] The three-phase unbalanced state quantities on the line switches of the three-phase unbalanced distribution network are collected, the three-phase unbalanced constraints of the three-phase unbalanced state quantities are described, and a three-phase unbalanced measurement matrix is ​​constructed based on the three-phase unbalanced constraints. The method includes: obtaining a topological connection relationship of the three-phase unbalanced distribution network based on the line switch positions and line connection relationships of the three-phase unbalanced distribution network; obtaining an association between the three-phase unbalanced state quantities on the line switches of the three-phase unbalanced distribution network based on the topological connection relationship of the three-phase unbalanced distribution network; constructing a three-phase unbalanced constraint based on the association; and constructing a three-phase unbalanced measurement matrix A with the numbers of the three-phase unbalanced constraint formulas as columns and the numbers of the three-phase unbalanced state quantities as rows.

[0053] like Figure 1 As shown in the figure, taking the three-phase unbalanced three-node distribution network system as an example, the state quantity collected from the smart meter is x = [x1, x1, x3], which supports the exponential increase of parameter dimensions. The state quantity also comes from the terminal measurement equipment in the SCADA system and is fed back to the smart meter side through each iteration.

[0054] x s =[x1,x2,x3,x4,x5,x6,x7,x8,x9], the feedback parameters come from the calculation on the server side, such as the parameter λ mentioned below.

[0055] In one embodiment, the measurement device of the three-phase unbalanced distribution network is a SCADA measurement device or a smart meter. The measurement of the sth SCADA measurement device is (P s,ij ,Q s,ij), ij is the branch where the measuring device s is located, or the downstream branch; the amount of the s-th smart meter is (P s,k ,Q s,k ,V k ), k is the load node number where the smart meter is located, P, Q and V represent the active injection power, reactive injection power and voltage amplitude on the branch or node where the measuring device is located, respectively.

[0056] In the embodiment, the corresponding constraints can be obtained by ensuring that the voltage phasors at both ends of the closed station switch are equal. For example:

[0057]

[0058] Substituting the actual collected measurement, for the single constraint x2=x5, considering the three-phase parameters, we have:

[0059]

[0060] The three-phase unbalance measurement matrix corresponding to the above constraints is constructed as follows:

[0061]

[0062] In one embodiment, the three-phase unbalance measurement matrix is ​​a matrix composed of measurement residuals. In order to implement state estimation, the power network of the present invention additionally takes into account zero-impedance elements, the estimated nodes are physical connection points, and the node voltages at both ends of the switch are additionally taken into account in the state variables. To this end, the collected information and the unbalance matrix are expanded accordingly. Figure 1 In the state variable, the voltage of the independent bus node and the voltage amplitude and phase angle information of the nodes at both ends of the switch are included.

[0063] Step 2: establish a communication verification mechanism using the three-phase unbalance measurement matrix, filter the three-phase unbalance state quantity to be transmitted using the communication verification mechanism, and transmit the three-phase unbalance event to the state estimation server.

[0064] In order to reduce unnecessary measurement transmission and alleviate the communication pressure of the distribution network, the present invention proposes a closed-loop event trigger mechanism, which no longer uploads measurement data at fixed time intervals, but only uploads the measurement data to the estimator when the trigger condition is met.

[0065] To this end, the line switch of the three-phase unbalanced distribution network is used as the measurement device, and the event generation function is constructed as follows:

[0066]

[0067] Where z t =[z s,t ] 1×nis the measurement of the measuring devices s = 1, 2, ..., n at the communication time t, where the measurement of the sth SCADA measuring device is (p s,ij ,Q s,ij );ij is the branch where the measuring device s is located, or the downstream branch; the amount measured by the s-th smart meter is (p s,k ,Q s,k ,V k ), k is the load node number where the smart meter is located, P, Q and V represent the active injected power, reactive injected power and voltage amplitude on the branch or node where the measuring device is located, respectively;

[0068] is the relevant state quantity of the current measuring device at the communication time t-1, where the relevant state quantity of the sth measuring device is It can be based on the measurement function Determine the current measurement z s,t Measurements of other related measuring devices;

[0069] a mn is the element in the mth row and nth column of the three-phase unbalance measurement matrix,

[0070] σ is the event threshold, and its specific value is obtained from offline experimental tests.

[0071] The communication verification mechanism is used to filter the three-phase unbalance state quantity to be transmitted, and the three-phase unbalance event is transmitted to the state estimation server, including: obtaining the event trigger logic variable γ of the sth measurement device according to the event generation function s,t ; If the event triggers the logical variable γ s,t =1, the three-phase unbalance event of the s-th measuring device is sent to the state estimation server.

[0072] An event triggering logic variable is obtained based on the event generation function. When it is greater than 0, that is, when the measurement error reaches the threshold, the event triggering logic variable is defined as 1, otherwise it is 0.

[0073]

[0074] Where g s For function The element corresponding to the s-th measurement device.

[0075] The triggered quantity measurement is obtained according to the event triggering logic variable. When it is 1, the real-time measurement is transmitted to the estimator, otherwise the measurement prediction value is transmitted.

[0076] Obtain the event trigger logic variable γ of the sth measurement device according to the event generation function s,t ,include:

[0077] If the result of the event generating function is The event generation quantity g of the sth measurement device is s,t , greater than 0, a three-phase unbalance event is generated

[0078]

[0079] Where,

[0080] Step 3: In the state estimation server, the received three-phase imbalance event is used to reconstruct a three-phase imbalance estimation quantity, and the measurement error auxiliary matrix pre-generated in the state estimation server is combined to construct a distribution network state estimation target.

[0081] In the state estimation server, reconstructing a three-phase imbalance estimation value using the received three-phase imbalance event includes:

[0082] Assume that the state transition of the three-phase unbalance event is but

[0083] Based on the measurement error auxiliary matrix R pre-generated in the state estimation server, the three-phase unbalance objective function is constructed as follows:

[0084]

[0085] In one embodiment, the state transition amount of the three-phase unbalance event may be the calculated measurement residual of each measured state amount in the measurement device.

[0086] Based on the three-phase unbalance measurement matrix A, the three-phase unbalance constraint condition is constructed as follows:

[0087] X=v

[0088] AX=0

[0089] Where v is the random error vector.

[0090] The measurement error auxiliary matrix R is stored in the state estimation server during the last iteration and has

[0091] R=[cov(x s ,x s′ )] n×n .

[0092] Where x s′ An element in the state transition quantity of another measurement device.

[0093] Solving the above formula yields:

[0094]

[0095] λ is the parameter vector newly introduced by the algorithm.

[0096] The distribution network state estimation target is constructed by combining the measurement error auxiliary matrix pre-generated in the state estimation server, including: the optimal solution of the three-phase unbalance objective function when the three-phase unbalance constraint condition is met is:

[0097]

[0098] Where λ=[λ1,λ2,…,λ i ,…λ N ], element λ i Calculated based on the random error vector v, where N is the number of parameters.

[0099] The embodiment of the present invention supports multiple communications between multiple smart meters, SCADA terminal devices and servers. Multiple iterations can ultimately yield the following iterative formula:

[0100]

[0101] k is the number of iterations,

[0102] Δλ (k) , ΔZ (k) With ΔX (k) are the correction amounts of parameters λ, Z and X during iteration respectively.

[0103] The coefficient matrix is ​​calculated as follows:

[0104]

[0105] Element λ i The calculation method is:

[0106] Cov(λ i ,λ i′ )=C1H T R -1 HC1 T =V λ

[0107] E(λ i )=E(C1H T R -1 v)=0

[0108] As mentioned earlier, v is a random error vector and therefore usually follows a white noise distribution.

[0109] During multiple iterations, the smart meter or SCADA terminal device on the switch side sends the filtered three-phase unbalance event to the server side according to the communication filtering method, and the server then sends the element λ i The parameters of the composition are λ=[λ1,λ2,…,λ i ,…λ N ]Distributed to the smart meter on the switch side.

[0110] Step 4: Solve the distribution network state estimation target to obtain the distribution network state estimation result.

[0111] Solving the distribution network state estimation objective to obtain a state estimation result of the distribution network includes:

[0112] The calculated threshold value is:

[0113]

[0114] Where, v λ,ii is a diagonal matrix The i-th element of ;

[0115] C1 is the coefficient matrix.

[0116] Based on the normal distribution characteristics, the false alarm probability is given, and the corresponding switch state can be identified as error information by calculating the threshold value. Ni If it is smaller than the transmission residual during iteration, it means that a switch state error occurs.

[0117] In this embodiment, the IEEE 13 three-phase asymmetric system is expanded to include a physical connection diagram with physical connection points. The measurement configuration is as follows: Smart meters are installed at independent nodes carrying loads to collect node-injected active power, reactive power, and voltage amplitude measurements; SCADA measurement equipment is installed on 50% of the branches to obtain branch headend active and reactive power measurements. During the simulation, measurement data is obtained by superimposing Gaussian noise on the true power flow value. The standard deviation for power measurement is set to 0.01, and for voltage amplitude measurement to 0.005.

[0118] The present invention uses the mean absolute error of node voltage amplitude and phase angle to measure the estimation accuracy of the proposed algorithm. The calculation formula is as follows:

[0119]

[0120] In the formula, N represents the number of state quantities, T represents the total number of time sections, Represent the estimated values ​​of the voltage amplitude and voltage phase angle of node i at time t, They represent the true values ​​of the voltage amplitude and voltage phase angle of node i at time t respectively.

[0121] The event trigger rate is:

[0122]

[0123] m Zet The number of real-time measurements actually transmitted to the estimation server to meet the trigger conditions; m Z is the total number of measurements collected by the measurement device.

[0124] Through offline testing, the trigger threshold of the SCADA measurement equipment is set to 0.0006, and the trigger threshold of the smart meter is set to 0.006. At this time, the average event trigger rate is 80%.

[0125] Figure 3 The figure shows the trigger counts for five measurement devices at an 80% event trigger rate. As can be seen, in conventional state estimation, real-time measurements are uploaded to the estimator at every estimation moment, resulting in each measurement device uploading 96 measurements. With the event-triggered mechanism, a measurement device only uploads real-time measurements when the trigger condition is met. As a result, the number of measurement triggers drops below 60, a reduction of approximately 37% compared to conventional periodic sampling.

[0126] Figure 4 The trigger time interval of the measuring device 1 under an 80% event trigger rate is shown. As can be seen from the figure, some trigger time intervals have been increased from 15 minutes in traditional periodic sampling to more than 30 minutes. The longest trigger time interval is 105 minutes, which greatly alleviates the communication pressure on the distribution network.

[0127] To demonstrate the estimation accuracy of the algorithm proposed in this invention, the algorithm (abbreviated as ET-GSE) is compared with the estimation algorithm of weighted least squares (WLS). The average event trigger rate in the test is 80%. Figure 5 and Figure 6 The mean absolute error of voltage amplitude and voltage phase angle between ET-GSE and WLS are shown. As can be seen from the figure, the estimation error of ET-GSE is almost the same as that of WLS, with an average error of 10 -3 It can be seen that the proposed algorithm can obtain accurate estimation results while reducing real-time measurement transmission.

[0128] To verify the topology recognition performance of the proposed algorithm, this section sets a topology error scenario: switches 6-8 are open but mistakenly considered closed. The false alarm probability is set to 0.005, and the threshold value is calculated using the norminv function in MATLAB to be 2.81. Figure 7 、 Figure 8 The maximum value of the communication parameters corresponding to each switch is shown. Figure 7It can be seen that the multiplier value of switch 6-8 exceeds the threshold value of 2.81, indicating that the state information of switch 6-8 is incorrect, which shows that the proposed algorithm can identify topology error information. Through the feedback communication transmission mechanism, after deleting the incorrect constraints in the three-phase unbalance measurement matrix, the maximum value of the communication parameters of each switch is recalculated. Figure 8 It can be seen that the multiplier value of each switch is less than the threshold value, which indicates that there is no switch status error information in the test system.

[0129] A second aspect of the present invention relates to an event-triggered distribution network state estimation system; the system is implemented using the method described in the first aspect of the present invention; the system includes an acquisition module, a filtering module, a construction module, and an estimation module; the acquisition module is used to acquire three-phase unbalanced state quantities on line switches of a three-phase unbalanced distribution network, describe three-phase unbalanced constraints of the three-phase unbalanced state quantities, and construct a three-phase unbalanced measurement matrix based on the three-phase unbalanced constraints; the filtering module is used to establish a communication verification mechanism using the three-phase unbalanced measurement matrix, use the communication verification mechanism to filter the three-phase unbalanced state quantities to be transmitted, and transmit three-phase unbalanced events to a state estimation server; the construction module is used to reconstruct a three-phase unbalanced estimation quantity in the state estimation server using the received three-phase unbalanced event, and construct a distribution network state estimation target in combination with a measurement error auxiliary matrix pre-generated in the state estimation server; the estimation module is used to solve the distribution network state estimation target to obtain a state estimation result of the distribution network.

[0130] A third aspect of the present invention relates to a terminal, comprising a processor and a storage medium; the storage medium is used to store instructions; and the processor is used to operate according to the instructions to execute the steps of the method described in the first aspect of the present invention.

[0131] A fourth aspect of the present invention relates to a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the method described in the first aspect of the present invention.

[0132] Finally, it should be noted that the above embodiments are intended only to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art will appreciate that the technical solutions of the present invention still include modifications or equivalent substitutions that may be made to the specific embodiments of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention are intended to be covered by the claims of the present invention.

Claims

1. A distribution network state estimation method based on event triggering, characterized in that: The method comprises the following steps: Collect the three-phase unbalanced state quantity on the line switch of the three-phase unbalanced distribution network, describe the three-phase unbalanced constraints of the three-phase unbalanced state quantity, and construct a three-phase unbalanced measurement matrix based on the three-phase unbalanced constraints; A communication verification mechanism is established using the three-phase unbalance measurement matrix, the communication verification mechanism is used to filter the three-phase unbalance state quantity to be transmitted, and the three-phase unbalance event is transmitted to the state estimation server; In the state estimation server, a three-phase imbalance estimation quantity is reconstructed using the received three-phase imbalance event, and a distribution network state estimation target is constructed in combination with a measurement error auxiliary matrix pre-generated in the state estimation server; The distribution network state estimation target is solved to obtain a state estimation result of the distribution network.

2. The method for estimating the state of a distribution network based on event triggering according to claim 1, characterized in that: The method of collecting three-phase unbalanced state quantities on the line switches of the three-phase unbalanced distribution network, describing three-phase unbalanced constraints of the three-phase unbalanced state quantities, and constructing a three-phase unbalanced measurement matrix based on the three-phase unbalanced constraints includes: Based on the line switch positions and line connection relationships of the three-phase unbalanced distribution network, a topological connection relationship of the three-phase unbalanced distribution network is obtained; Obtaining, based on a topological connection relationship of the three-phase unbalanced distribution network, an association of three-phase unbalanced state quantities on circuit switches of the three-phase unbalanced distribution network; constructing a three-phase unbalance constraint based on the association; A three-phase unbalance measurement matrix A is constructed with the numbers of the three-phase unbalance constraint equations as columns and the numbers of the three-phase unbalance state quantities as rows.

3. The method for estimating the state of a distribution network based on event triggering according to claim 2, characterized in that: The method of establishing a communication verification mechanism by utilizing the three-phase unbalance measurement matrix includes: According to the measurement devices of the three-phase unbalanced distribution network, the SCADA measurement device and the smart meter, the event generation function is constructed as follows: Where z t =[z s,t ] 1×n is the measurement of the measuring devices s = 1, 2, ..., n at the communication time t, where the measurement of the sth SCADA measuring device is (P s,ij ,Q s,ij );ij is the branch where the measuring device s is located, or the downstream branch; the amount of the s-th smart meter is (P s,k ,Q s,k ,V k ), k is the load node number where the smart meter is located, P, Q and V represent the active injected power, reactive injected power and voltage amplitude on the branch or node where the measuring device is located, respectively; is the relevant state quantity of the current measuring device at the communication time t-1; a mn is the element in the mth row and nth column of the three-phase unbalance measurement matrix; σ is the event threshold.

4. The method for estimating distribution network state based on event triggering according to claim 3, characterized in that: The method of filtering the three-phase unbalanced state quantity to be transmitted by adopting the communication verification mechanism and transmitting the three-phase unbalanced event to the state estimation server includes: Obtain the event trigger logic variable γ of the sth measuring device according to the event generation function s,t ; If the event triggers the logical variable γ s,t =1, the three-phase unbalance event of the s-th measuring device is sent to the state estimation server.

5. The method for estimating distribution network state based on event triggering according to claim 4, characterized in that: The event triggering logic variable γ of the sth measuring device is obtained according to the event generation function s,t ,include: If the result of the event generating function is The event generation quantity g of the sth measurement device is s,t , greater than 0, a three-phase unbalance event is generated Where, 6. The method for estimating distribution network state based on event triggering according to claim 5, characterized in that: The state estimation server reconstructs a three-phase imbalance estimation value by using the received three-phase imbalance event, including: Assume that the state transition of the three-phase unbalance event is but Based on the measurement error auxiliary matrix R pre-generated in the state estimation server, the three-phase unbalance objective function is constructed as follows: Based on the three-phase unbalance measurement matrix A, the three-phase unbalance constraint condition is constructed as follows: X=v AX=0 Where v is the random error vector.

7. The method for estimating distribution network state based on event triggering according to claim 6, characterized in that: The measurement error auxiliary matrix R is stored in the state estimation server during the last iteration process and has R=[cov(x s ,x s′ )] n×n Where x s′ An element in the state transition quantity of another measurement device.

8. The method for estimating distribution network state based on event triggering according to claim 7, characterized in that: The method of constructing a distribution network state estimation target by combining a measurement error auxiliary matrix pre-generated in the state estimation server includes: The optimal solution of the three-phase unbalance objective function when the three-phase unbalance constraint condition is met is: Where λ=[λ1,λ2,…,λ i ,…λ N ], element λ i Calculated based on the random error vector v, where N is the number of parameters.

9. The method for estimating distribution network state based on event triggering according to claim 8, characterized in that: The solving the distribution network state estimation target to obtain the distribution network state estimation result includes: The calculated threshold value is: Where, v λ,ii is a diagonal matrix The i-th element of ; C1 is the coefficient matrix.

10. A distribution network state estimation system based on event triggering, characterized by: The system is implemented using a distribution network state estimation method based on event triggering according to any one of claims 1 to 9; The system includes an acquisition module, a filtering module, a construction module, and an estimation module; The acquisition module is used to acquire three-phase unbalanced state quantities on the circuit breaker of the three-phase unbalanced distribution network, describe the three-phase unbalanced constraints of the three-phase unbalanced state quantities, and construct a three-phase unbalanced measurement matrix based on the three-phase unbalanced constraints; The filtering module is configured to establish a communication verification mechanism using the three-phase unbalance measurement matrix, filter the three-phase unbalance state quantity to be transmitted using the communication verification mechanism, and transmit the three-phase unbalance event to the state estimation server; The construction module is configured to reconstruct a three-phase imbalance estimation value in the state estimation server using the received three-phase imbalance event, and construct a distribution network state estimation target in combination with a measurement error auxiliary matrix pre-generated in the state estimation server; The estimation module is used to solve the distribution network state estimation target to obtain the distribution network state estimation result.

11. A terminal comprising a processor and a storage medium; characterized in that: The storage medium is used to store instructions; The processor is configured to operate according to the instructions to execute the steps of the method according to any one of claims 1 to 9.

12. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the steps of the method according to any one of claims 1 to 9 are implemented.

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