Reliability estimation method for grid-connected power supply coordination performance

Abstract

The present invention relates to a reliability estimation method for the network source coordination performance of a grid-connected power supply, comprising: obtaining information on grid-related test items of the grid-connected power supply; obtaining abnormal events and fault events that affect the safe and stable operation of a power grid due to the failure of the grid-related test performance of the grid-connected power supply to meet the network source coordination technical specifications, filtering out factors not related to the unqualified network-related test performance of the grid-connected power supply itself, and then counting the number of each network-related test item that meets data cleaning conditions and affects the stable operation of the power grid within a cycle time; calculating the mean time between failures MTBF and the failure rate λ of each network-related test performance of the grid-connected power supply within the statistical cycle; the reliability of the network source coordination performance of the grid-connected power supply within the statistical cycle can further analyze the main network-related test performance items that affect its reliability, find out the weak links of the network-related performance, and serve as the main basis for strengthening the management of the project.

Description

Technical Field

[0001] The present invention relates to the technical field of performance estimation of a grid-connected power supply, and in particular to a reliability estimation method for network source coordination performance of a grid-connected power supply. Background Art

[0002] The dynamic performance of the new power grid is more complex, especially the reduction of system damping, which will significantly increase the power oscillation of the system, and the power grid is at risk of frequency crossing the line or even instability. At the same time, with the continuous advancement of UHV DC projects, since DC and new energy plants do not have the dynamic reactive power support capacity of conventional power sources, the system dynamic reactive power reserve is reduced, and the grid voltage is also at risk of collapse.

[0003] In order to solve the technical challenges brought by the "double high" power grid under the new form, fully tapping the performance of traditional synchronous generators and new energy stations has become the key to solving the risk of instability in the power grid system. Therefore, conducting grid-related tests on grid-related equipment of grid-connected power sources has become an effective technical measure to ensure the stability of the power system. Furthermore, effective evaluation and analysis of grid-related tests carried out on grid-connected power sources will help to grasp the performance status of grid-related equipment required by grid-source coordination and form effective evaluation and management methods.

[0004] Therefore, it is of great significance to study the grid-connected power supply coordination performance analysis and evaluation method based on reliability engineering theory, taking grid-related protection and related test results as basic elements. Summary of the invention

[0005] The purpose of the present invention is to provide a reliability estimation method for the network source coordination performance of a grid-connected power supply, so as to solve the technical problem that the network source coordination performance of the grid-connected power supply cannot be quantitatively estimated in the prior art.

[0006] The technical solution of the present invention is:

[0007] A reliability estimation method for network source coordination performance of a grid-connected power supply comprises the following steps:

[0008] Step 1: Obtain grid-related test project information of the grid-connected power supply;

[0009] Step 2: Obtain abnormal events and fault events that affect the safe and stable operation of the power grid due to the failure of the grid-related test performance of the grid-connected power source to meet the grid source coordination technical specifications, filter out factors that are not unqualified for the grid-related test performance, and count the number of grid-related test items that affect the stable operation of the power grid that meet the data cleaning conditions within the statistical period;

[0010] Step 3: Calculate the mean time between failures (MTBF) of each grid-related test performance of the grid-connected power supply within the statistical period according to the data cleaning results;

[0011] Step 4: Calculate the corresponding failure rate λ according to the MTBF index of each network-related test performance;

[0012] Step 5: Reliability of the grid-connected power supply's coordination performance within the statistical period In the formula, i is the i-th unit of the series structure contained in the entire research object; n is the total number of series structures contained in the entire research object; R i (t) is the reliability of the i-th unit in the statistical period t, Where λ is the failure rate and t is the statistical period.

[0013] Preferably, in step 1, the grid-related test project information of the grid-connected power supply obtained includes the test cycle, test results, and record information of abnormal events and fault events that occurred during operation and affected the stability of grid operation.

[0014] Preferably, the non-self-network-related test performance unqualified factors include other equipment failure factors, operation and maintenance factors, operation environment factors and weather factors.

[0015] The beneficial effects of the present invention are:

[0016] 1. Taking the grid-related test performance of grid-connected power supply as the basic unit and combining it with reliability engineering theory, a grid-source coordination reliability assessment method for grid-connected power supply is formed, which provides a theoretical basis for the systematic quantitative analysis of the grid-source coordination performance of grid-connected power supply, provides a statistical analysis method for the detailed analysis of weak grid-related test items that affect the grid-source coordination performance, and provides technical support for the continuous strengthening of the management of grid-source coordination technical specifications. DETAILED DESCRIPTION

[0017] The present invention is described below in the form of embodiments to assist those skilled in the art in understanding and implementing the present invention. Unless otherwise specified, the following embodiments and the technical terms therein should not be understood without departing from the technical knowledge background of the technical field.

[0018] The object of the present invention is the grid-source coordination performance of the grid-connected power supply, and the specific basis is the test results of the test items in the grid-related test and grid-related protection contained in the grid-source coordination technical specifications.

[0019] The grid-connected power supply equipment of the present invention includes: generators, excitation systems and power system stabilizers (PSS), prime movers and regulation systems, generator-transformer protection systems, automatic voltage control (AVC), automatic generation control (AGC), static VAR compensators (SVC), static VAR generators (SVG), phase regulators and other reactive power compensation devices, wind power and photovoltaic control systems and protection devices, auxiliary machine inverters of power plants, phasor measurement units (PMUs), and other equipment that can affect the stability of the power grid.

[0020] During the implementation process, it is necessary to collect and sort out the types of relevant grid-related test items of the grid-connected power plant, sort out the grid-related test time, performance indicators, and test conclusions of the plant, and establish a historical database for statistics, retrieval, and management of the grid-related test items of each grid-connected power plant. The grid-related tests included in the present invention include grid-related tests of synchronous generator sets and grid-related tests of new energy stations. The grid-related tests of synchronous generator sets included in the present invention include: excitation system parameter tests and modeling tests, speed regulation system parameter and modeling tests, PSS setting tests, phase advance tests, primary frequency regulation tests, AGC tests, AVC tests, high and low voltage ride-through tests of the first-class auxiliary machine inverters in power plants, PMU performance tests, grid-related protection matching verification, and other tests necessary to ensure system safety. The grid-related tests of new energy stations included in the present invention include: power quality test, active power control capability test, reactive power / voltage control capability test, reactive power compensation device grid-connected performance test, inertia response and primary frequency regulation test, plant modeling and model verification, fault ride-through capability simulation verification, voltage and frequency adaptability verification, and other tests necessary to ensure system safety.

[0021] The reliability structure model established by the present invention is: taking the stable and reliable network source coordination performance of a single unit as the top event tree, taking the network-related test performance results of various types of grid-connected power plants and stations as sub-events, and establishing the network source coordination performance reliability structure model of the grid-connected power plant and station. Since the reliable network source coordination performance is the task target of each grid-connected power plant and station, and the performance results of each grid-related test of the grid-connected power supply are independent units, the series model is selected as the reliability structure model of the method of the present invention.

[0022] The reliability estimation method of the network source coordination performance of the grid-connected power supply of the present invention comprises the following steps:

[0023] Step 1: For the grid-connected power supply, take stable and reliable network source coordination performance as the task goal, and draw a reliability structure block diagram according to the series reliability structure.

[0024] Step 2: Collect and organize the grid-related test project information of each grid-connected power source, including the test cycle, test results, and record information of abnormal events and fault events that occurred during operation and affected the stability of grid operation.

[0025] Step 3: Select the abnormal events and fault events that affect the safe and stable operation of the power grid due to the failure of the grid-related test performance of the grid-connected power supply to meet the grid source coordination technical specifications, filter out other factors not related to the unqualified grid-related test performance, such as other equipment failures, operation and maintenance, operating environment, weather, etc., screen and filter the abnormal events and fault events that involve and affect the stability of the grid operation of each grid-connected power supply, and count the number of each grid-related test items that affect the stable operation of the grid that meet the data cleaning conditions within the cycle time.

[0026] Step 4: Calculate the mean time between failures (MTBF) of each grid-related test performance of the grid-connected power supply within a certain statistical period based on the data cleaning results. The calculation method of the mean time between failures (MTBF) is a common method used by those skilled in the art and will not be described in detail here.

[0027] Step 5: Calculate the corresponding failure rate λ according to the MTBF index of each network-related test performance. The calculation method of the failure rate λ is a common method for those skilled in the art and will not be described in detail here.

[0028] Step 6: Select a suitable fault distribution function. Taking exponential distribution as an example, the reliability of a network-related test performance within a certain statistical period can be obtained.

[0029]

[0030] In the formula, i is the research unit; λ is the failure rate; t is the statistical period;

[0031] The reliability of the grid-connected power supply within the statistical period can be obtained by using the reliability structure model established in step 1 to obtain the reliability of the grid-connected power supply's network source coordination performance.

[0032]

[0033] Where, j is the jth unit of the series structure contained in the entire research object; n is the total number of series structures contained in the entire research object; R j (t) is the reliability of the jth unit in the statistical period t.

[0034] Based on the calculated reliability results of the grid-connected power supply's grid-source coordination performance, we further analyze the main grid-related test performance items that affect its reliability, identify the weak links in the grid-related performance, and use this as the main basis for strengthening the project management and filling in the gaps.

[0035] Give full play to the definition characteristics of reliability engineering theory that products must complete specified functions within a specified time, and achieve the goals of periodic evaluation and periodic management of non-equipment and facility carriers such as network-related test performance.

[0036] The present invention has been described in detail above with reference to the embodiments. It should be understood that it is impossible to describe all possible implementation methods in practice, and the inventive concept of the present invention is described as much as possible by way of example. Without departing from the inventive concept of the present invention and without creative work, the technical personnel in this technical field make selections and combinations of the technical features in the above embodiments, make experimental changes to the specific parameters, or use the prior art in this technical field to conventionally replace the technical means disclosed in the present invention to form specific embodiments, which should all belong to the implicit disclosure of the present invention.

Claims

1. A reliability estimation method for the network source coordination performance of a grid-connected power supply, characterized in that: The following steps are involved: Step 1: Obtain grid-related test project information of the grid-connected power supply; Step 2: Obtain abnormal events and fault events that affect the safe and stable operation of the power grid due to the failure of the grid-related test performance of the grid-connected power source to meet the grid source coordination technical specifications, filter out factors that are not unqualified for the grid-related test performance, and count the number of grid-related test items that affect the stable operation of the power grid that meet the data cleaning conditions within the statistical period; Step 3: Calculate the mean time between failures (MTBF) of each grid-related test performance of the grid-connected power supply within the statistical period according to the data cleaning results; Step 4: Calculate the corresponding failure rate λ according to the MTBF index of each network-related test performance; Step 5: Reliability of the grid-connected power supply's coordination performance within the statistical period , where i is the i-th unit of the series structure contained in the entire research object; n is the total number of series structures contained in the entire research object; is the reliability of the ith unit in the statistical period t, , where λ is the failure rate; t is the statistical period; In the step 1, the grid-related test project information of the grid-connected power supply obtained includes the test cycle, test results, and record information of abnormal events and fault events that occurred during operation and affected the stability of the power grid operation; the non-self-grid-related test performance unqualified factors include other equipment failure factors, operation and maintenance factors, operating environment factors and weather factors; The grid-related tests include grid-related tests for synchronous generator sets and grid-related tests for new energy stations; The estimation method further includes: obtaining main grid-related test performance items that affect the reliability of the grid-connected power supply according to the reliability result of the grid source coordination performance of the grid-connected power supply.

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