CN-115015675-B - Medium-voltage distribution network line parameter estimation method and device

CN115015675BCN 115015675 BCN115015675 BCN 115015675BCN-115015675-B

Abstract

The invention discloses a medium-voltage distribution network line parameter estimation method and device. The medium voltage distribution network line parameter estimation method is suitable for intelligent terminals configured on any power supply section of the medium voltage distribution network, and comprises the steps of collecting local power flow data in each preset period, obtaining power flow data collected by adjacent intelligent terminals of the intelligent terminals as remote power flow data, constructing a line parameter estimation model based on pi-type equivalent circuits of lines between the intelligent terminals and the adjacent intelligent terminals, and solving the line parameter estimation model according to the local power flow data and the remote power flow data to obtain line parameter estimation values of the lines. The method and the system can accurately estimate the line parameters of the medium-voltage distribution network at regular time according to the local power flow data and the power flow data of the adjacent intelligent terminals.

Inventors

CHEN PEIDONG
YANG YIFEI
LIN LINGXUE
GAO CHONG
CAO HUAZHEN
HE XUAN
ZHANG JUNXIAO
DUAN YAO
XU ZHIHENG
HUANG YE
ZHANG YONGJIE

Assignees

广东电网有限责任公司

Dates

Publication Date: 20260512
Application Date: 20220708

Claims (8)

1. The method is characterized by being suitable for intelligent terminals configured on any power supply section of the medium-voltage distribution network, and comprises the following steps: Collecting local tide data in each preset period, and acquiring tide data collected by an adjacent intelligent terminal of the intelligent terminal as remote tide data; Constructing a line parameter estimation model based on a pi-type equivalent circuit of a line between the intelligent terminal and the adjacent intelligent terminal; according to the local power flow data and the remote power flow data, solving the line parameter estimation model to obtain a line parameter estimation value of the line, wherein the line parameter estimation model is as follows: ; Wherein R is the resistance of the line, X is the reactance of the line, B C is the equivalent capacitance to ground of the line, wherein the resistance, reactance and equivalent capacitance to ground are all the line parameters required to be solved, P 1 is the active power of the line head end, Q 1 is the reactive power of the line head end, P 2 is the active power of the line tail end, Q 2 is the reactive power of the line tail end, U 1 is the voltage of the line head end, and U 2 is the voltage of the line tail end.
2. The medium voltage distribution network line parameter estimation method according to claim 1, wherein the step of collecting local power flow data and obtaining power flow data collected by an adjacent intelligent terminal of the intelligent terminal as remote power flow data in each preset period includes: collecting bus voltage of a power supply section where the intelligent terminal is located and active power and reactive power of each distribution line as the local tide data in each preset period; And in each preset period, determining adjacent intelligent terminals of the intelligent terminals based on the topological structure of the medium-voltage distribution network, and acquiring bus voltage of a power supply section where the adjacent intelligent terminals are positioned and active power and reactive power of each distribution line as the remote tide data.
3. The medium voltage distribution network line parameter estimation method according to claim 1, wherein the step of solving the line parameter estimation model according to the local power flow data and the remote power flow data to obtain a line parameter estimation value of the line comprises the following steps: And solving the line parameter estimation model by adopting a Newton iteration method according to the local power flow data and the remote power flow data until the estimated error is smaller than a preset error, and obtaining the line parameter estimated value of the line.
4. A medium voltage distribution network line parameter estimation method according to claim 3, wherein the estimation error is: ; Wherein R (i+1) is the resistance of the line obtained in the (i+1) th iteration, R (i) is the resistance of the line obtained in the (i+1) th iteration, X (i+1) is the reactance of the line obtained in the (i+1) th iteration, X (i) is the reactance of the line obtained in the (i+1) th iteration, B C (i+1) is the reactance of the line obtained in the (i+1) th iteration, and B C (i) is the reactance of the line obtained in the (i) th iteration.
5. A medium voltage distribution network line parameter estimation device, which is suitable for an intelligent terminal configured on any power supply section of the medium voltage distribution network, the device comprising: The data acquisition module is used for acquiring local tide data in each preset period and acquiring tide data acquired by an adjacent intelligent terminal of the intelligent terminal as remote tide data; The model construction module is used for constructing a circuit parameter estimation model based on a pi-type equivalent circuit of a circuit between the intelligent terminal and the adjacent intelligent terminal; The parameter estimation module is configured to solve the line parameter estimation model according to the local power flow data and the remote power flow data, to obtain a line parameter estimation value of the line, where the line parameter estimation model is: ; Wherein R is the resistance of the line, X is the reactance of the line, B C is the equivalent capacitance to ground of the line, wherein the resistance, reactance and equivalent capacitance to ground are all the line parameters required to be solved, P 1 is the active power of the line head end, Q 1 is the reactive power of the line head end, P 2 is the active power of the line tail end, Q 2 is the reactive power of the line tail end, U 1 is the voltage of the line head end, and U 2 is the voltage of the line tail end.
6. The medium voltage distribution network line parameter estimation apparatus of claim 5, wherein the data acquisition module comprises: The local power flow data acquisition unit is used for acquiring bus voltage of a power supply section where the intelligent terminal is located and active power and reactive power of each distribution line as the local power flow data in each preset period; And the remote tide data acquisition unit is used for determining adjacent intelligent terminals of the intelligent terminals based on the topological structure of the medium-voltage distribution network in each preset period, and acquiring bus voltage of a power supply section where the adjacent intelligent terminals are positioned and active power and reactive power of each distribution line as the remote tide data.
7. The medium voltage distribution network line parameter estimation device according to claim 5, wherein the parameter estimation module is specifically configured to solve the line parameter estimation model by using newton's iteration method according to the local power flow data and the off-site power flow data until a line parameter estimation value of the line is obtained when an estimation error is smaller than a preset error.
8. The medium voltage distribution network line parameter estimation apparatus according to claim 7, wherein the estimation error is: ; Wherein R (i+1) is the resistance of the line obtained in the (i+1) th iteration, R (i) is the resistance of the line obtained in the (i+1) th iteration, X (i+1) is the reactance of the line obtained in the (i+1) th iteration, X (i) is the reactance of the line obtained in the (i+1) th iteration, B C (i+1) is the reactance of the line obtained in the (i+1) th iteration, and B C (i) is the reactance of the line obtained in the (i) th iteration.

Description

Medium-voltage distribution network line parameter estimation method and device Technical Field The invention relates to the technical field of power distribution network line parameter estimation, in particular to a medium-voltage power distribution network line parameter estimation method and device. Background The medium voltage distribution network is a tie for connecting a power supply system with users and is also an important component for building urban infrastructure. Along with the rapid economic development, in order to meet the rapidly-increased load demand of a user side, the scale and the structure of a medium-voltage distribution network are huge and complex, the phenomena of randomness, dispersibility and the like of the access of a photovoltaic and other distributed power sources lead to increasingly complex and changeable trend distribution, objects to be monitored are more and more, the medium-voltage distribution network is developed towards the direction of distributed cooperative control in the future, namely a distribution terminal with intelligent decision-making capability is configured at a key distribution ring network point, monitoring and judging information is exchanged through the interactive communication between adjacent intelligent terminals, and various control, protection and regulation functions of the medium-voltage distribution network are realized in a partition autonomous and cooperative mode. The distributed control and decision based on the intelligent terminal generally need the related information such as the line parameters of the medium voltage distribution network. Under the influence of external environment, the line parameters of the medium-voltage distribution network can change to a certain extent in actual operation, and if the initial parameters and the line distance of the line delivery are always taken as references, the line operation state is difficult to evaluate accurately, so that the distributed control or decision deviation is caused. Therefore, it is necessary to estimate line parameters of the medium voltage distribution network with timing accuracy. Disclosure of Invention In order to overcome the defects of the prior art, the invention provides a medium-voltage distribution network line parameter estimation method and device, which can accurately estimate the line parameter of a medium-voltage distribution network at regular time according to local power flow data and power flow data of adjacent intelligent terminals. In order to solve the above technical problems, in a first aspect, an embodiment of the present invention provides a method for estimating a line parameter of a medium voltage distribution network, which is applicable to an intelligent terminal configured on any power supply section of the medium voltage distribution network, and the method includes: Collecting local tide data in each preset period, and acquiring tide data collected by an adjacent intelligent terminal of the intelligent terminal as remote tide data; Constructing a line parameter estimation model based on a pi-type equivalent circuit of a line between the intelligent terminal and the adjacent intelligent terminal; And solving the line parameter estimation model according to the local power flow data and the remote power flow data to obtain a line parameter estimation value of the line. Further, in each preset period, collecting local power flow data, and obtaining power flow data collected by an adjacent intelligent terminal of the intelligent terminal as remote power flow data, including: collecting bus voltage of a power supply section where the intelligent terminal is located and active power and reactive power of each distribution line as the local tide data in each preset period; And in each preset period, determining adjacent intelligent terminals of the intelligent terminals based on the topological structure of the medium-voltage distribution network, and acquiring bus voltage of a power supply section where the adjacent intelligent terminals are positioned and active power and reactive power of each distribution line as the remote tide data. Further, the line parameter estimation model is: Wherein R is the resistance of the line, X is the reactance of the line, B C is the equivalent capacitance to ground of the line, P 1 is the active power of the line head, Q 1 is the reactive power of the line head, P 2 is the active power of the line tail, Q 2 is the reactive power of the line tail, U 1 is the voltage of the line head, and U 2 is the voltage of the line tail. Further, the step of solving the line parameter estimation model according to the local power flow data and the remote power flow data to obtain a line parameter estimation value of the line, specifically: And solving the line parameter estimation model by adopting a Newton iteration method according to the local power flow data and the remote power flow data until the estimated error is smaller