Modular switch cabinet reliability evaluation method based on reliability coefficient

Abstract

The invention discloses a modular switch cabinet reliability evaluation method based on a reliability coefficient. Comprising the following steps: measuring the pressure intensity of gas in the switch cabinet, measuring the humidity of the gas in the switch cabinet, measuring the temperature of each module in the switch cabinet, measuring the voltage of each module in the switch cabinet, measuring the current of a main loop in the switch cabinet, calculating a reliability coefficient, and evaluating the reliability of the switch cabinet. The method has the beneficial effects that by measuring the pressure intensity, the humidity, the temperature, the voltage and the current in the switch cabinet and calculating the reliability coefficient, the reliability of the modular switch cabinet is evaluated, and potential safety hazards can be effectively identified. The method is helpful for maintainers to take corresponding prevention and response measures, so that the safety and reliability of the modular switch cabinet are ensured.

Description

Technical Field

[0001] The present invention belongs to the field of reliability assessment of power equipment, and particularly relates to a reliability assessment method for modular switchgear based on a reliability coefficient. Background Art

[0002] The switchgear is an important and indispensable device in the power system. Its main functions include power grid control, circuit switching, and protection of power equipment. The safe and stable operation of the switchgear is of great significance for ensuring the reliability of the entire power grid power supply. However, for the switchgear after the integration of each unit into a modular form, it is still necessary to evaluate whether the operating states of its various modules are reliable. The reliability state assessment of the modular switchgear mainly relies on regular tests by staff, but this method has disadvantages such as long detection cycles, high detection costs, low test efficiency, and affecting the normal operation of the equipment. Moreover, manual regular inspections cannot conduct real-time assessments on the reliable states of the operating switchgear, often resulting in failures within the switchgear not being discovered in a timely manner.

[0003] Currently, there are still relatively few reliability assessment methods for modular switchgear, and there is no assessment method that has been widely promoted and applied. The present invention proposes a reliability assessment method for modular switchgear based on a reliability coefficient, and then evaluates the reliability of the switchgear. The assessment method proposed by the present invention is simple and can realize the online assessment of the reliability state of the switchgear. Summary of the Invention

[0004] The present invention is a reliability assessment method for modular switchgear based on a reliability coefficient. This method is simple and convenient to operate, and can effectively evaluate the reliability state of the switchgear by calculating the reliability coefficient.

[0005] The technical solution of the present invention is as follows:

[0006] First step: Measure the internal gas pressure of the switchgear

[0007] Measure the internal gas pressure of the switchgear ten times at intervals of 10 seconds using a pressure sensor, and record it as P i , unit: Pa, i represents the air temperature measured for the i-th time, i = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10}, and take the average value of the ten measured gas pressures as the internal gas pressure P of the switchgear a , unit: kP a :

[0008]

[0009] Second step: Measure the internal gas humidity of the switchgear

[0010] Measure the internal gas humidity of the switchgear ten times at intervals of 10 seconds using a humidity sensor, and record it as S i, unit: %, where \(i\) represents the humidity of the measured gas for the \(i\)-th time, \(i = \{1, 2, 3, 4, 5, 6, 7, 8, 9, 10\}\), and the average value of the humidity of the measured gas for ten times is used as the humidity \(S\) of the gas inside the switchgear a , unit: %:

[0011]

[0012] Step 3: Measure the temperature of each module inside the switchgear

[0013] At intervals of 10 seconds, use a temperature sensor to measure the temperature of each module inside the switchgear ten times, denoted as \(T\) ij , unit: K, where \(i\) represents the temperature of each module inside the switchgear measured for the \(i\)-th time, \(i = \{1, 2, 3, 4, 5, 6, 7, 8, 9, 10\}\), and \(j\) represents each module in the switchgear, \(j = \{1, 2, 3, 4\}\). The average value of the temperatures of each module measured ten times is used as the temperature \(T\) inside the switchgear a , unit: K:

[0014]

[0015] Step 4: Measure the voltage of each module inside the switchgear

[0016] At intervals of 10 seconds, use a voltage transformer to measure the voltage of each module inside the switchgear ten times, denoted as \(U\) ij , unit: kV, where \(i\) represents the voltage of each module inside the switchgear measured for the \(i\)-th time, \(i = \{1, 2, 3, 4, 5, 6, 7, 8, 9, 10\}\), and \(j\) represents each module in the switchgear, \(j = \{1, 2, 3, 4\}\). The average value of the voltages of each module measured ten times is used as the voltage \(U\) inside the switchgear a , unit: kV:

[0017]

[0018] Step 5: Measure the main circuit current inside the switchgear

[0019] At intervals of 10 seconds, use a current transformer to measure the main circuit current inside the switchgear ten times, denoted as \(I\) i , unit: A, where \(i\) represents the current measured for the \(i\)-th time, \(i = \{1, 2, 3, 4, 5, 6, 7, 8, 9, 10\}\). The average value of the currents measured ten times is used as the main circuit current \(I\) inside the switchgear a , unit: kA:

[0020]

[0021] Step 6: Calculate the reliability coefficient

[0022] Risk coefficient \(\delta\) f Calculate according to formula (6):

[0023] δ f = ln(0.93T a + 2.12P a - 1.47I a - 1.53U a + 0.05T a S a + 2.56I a U a ) (6)

[0024] Step 7: Evaluate the reliability of the modular switchgear

[0025] If δ f ≤ 5.994, the reliability of the measured modular switchgear is good;

[0026] If δ f > 5.994, the reliability of the measured modular switchgear is poor. Brief Description of the Drawings

[0027] Figure 1 is a flowchart of a method for evaluating the reliability of a modular switchgear based on a reliability coefficient according to the present invention. Detailed Embodiments

[0028] The present invention will be further described below in conjunction with the drawings and specific implementation processes;

[0029] Step 1: Measure the internal gas pressure of the switchgear

[0030] Measure the internal gas pressure of the switchgear ten times at intervals of 10 seconds using a pressure sensor, denoted as P i , unit: Pa, i represents the i-th measurement of the air temperature, i = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10}, and take the average value of the ten measured gas pressures as the internal gas pressure P of the switchgear a , unit: kP a :

[0031]

[0032] Step 2: Measure the internal gas humidity of the switchgear

[0033] Measure the internal gas humidity of the switchgear ten times at intervals of 10 seconds using a humidity sensor, denoted as S i , unit: %, i represents the i-th measurement of the gas humidity, i = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10}, and take the average value of the ten measured gas humidities as the internal gas humidity S of the switchgear a , unit: %:

[0034]

[0035] Step 3: Measure the temperatures of each module inside the switchgear

[0036] Measure the temperatures of each module inside the switchgear ten times at 10 - second intervals, denoted as T ij , unit: K. Here, i represents the i - th measurement of the temperatures of each module inside the switchgear, i = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10}, and j represents each module in the switchgear, j = {1, 2, 3, 4}. Take the average of the ten - time measured temperatures of each module as the internal temperature T of the switchgear a , unit: K:

[0037]

[0038] Step 4: Measure the voltages of each module inside the switchgear

[0039] Measure the voltages of each module inside the switchgear ten times at 10 - second intervals, denoted as U ij , unit: kV. Here, i represents the i - th measurement of the voltages of each module inside the switchgear, i = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10}, and j represents each module in the switchgear, j = {1, 2, 3, 4}. Take the average of the ten - time measured voltages of each module as the internal voltage U of the switchgear a , unit: kV:

[0040]

[0041] Step 5: Measure the main circuit current inside the switchgear

[0042] Measure the main circuit current inside the switchgear ten times at 10 - second intervals, denoted as I i , unit: A. Here, i represents the i - th measurement of the current, i = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10}. Take the average of the ten - time measured currents as the main circuit current I inside the switchgear a , unit: kA:

[0043]

[0044] Step 6: Calculate the reliability coefficient

[0045] Risk coefficient δ f Calculate according to formula (6):

[0046] δ f = ln(0.93T a + 2.12P a - 1.47I a - 1.53U a+0.05T a S a + 2.56I a U a ) (6)

[0047] Step 7: Evaluate the reliability of the modular switchgear

[0048] If δ f ≤5.994, the reliability of the tested modular switchgear is good;

[0049] If δ f >5.994, the reliability of the tested modular switchgear is poor.

Claims

1. A reliability evaluation method for modular switchgear based on reliability coefficient, characterized in that The following steps are involved: Step 1: Measure the gas pressure inside the switch cabinet At 10-second intervals, use the pressure sensor to measure the gas pressure inside the switch cabinet ten times, recorded as P i , unit: Pa, i represents the i-th measured air temperature, i = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10}, the average value of the ten measured gas pressures is taken as the internal gas pressure P of the switch cabinet a , unit: kP a : Step 2: Measure the humidity of the gas inside the switch cabinet The humidity sensor is used to measure the humidity of the gas inside the switch cabinet ten times at an interval of 10 seconds, recorded as S i , unit: %, i represents the i-th measured gas humidity, i = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10}, the average value of the ten measured gas humidity is taken as the internal gas humidity S of the switch cabinet a ,unit:%: Step 3: Measure the temperature of each module inside the switch cabinet At 10-second intervals, use the temperature sensor to measure the temperature of each module inside the switch cabinet ten times, recorded as T ij , unit: K, i represents the temperature of each module in the switch cabinet for the i-th time, i = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10}, j represents each module in the switch cabinet, j = {1, 2, 3, 4}, and the average value of the temperature of each module measured ten times is taken as the internal temperature T of the switch cabinet a , unit: K: Step 4: Measure the voltage of each module inside the switch cabinet At 10-second intervals, use a voltage transformer to measure the voltage of each module inside the switch cabinet ten times, recorded as U ij , unit: kV, i represents the voltage of each module in the switch cabinet measured for the i-th time, i={1,2,3,4,5,6,7,8,9,10}, j represents each module in the switch cabinet, j={1,2,3,4}, and the average value of the voltage of each module measured ten times is taken as the internal voltage U of the switch cabinet a , unit: kV: Step 5: Measure the main circuit current inside the switch cabinet At 10-second intervals, use a current transformer to measure the main circuit current inside the switch cabinet ten times, recorded as I i , unit: A, i represents the i-th measured current, i={1,2,3,4,5,6,7,8,9,10}, the average value of ten measured currents is taken as the main circuit current I inside the switch cabinet a , unit: kA: Step 6: Calculate the reliability coefficient Risk factor δ f Calculate according to formula (6): δ f =ln(0.93T a +2.12P a -1.47I a -1.53U a +0.05T a S a +2.56I a You a ) (6) Step 7: Evaluate the reliability of modular switchgear If δ f ≤5.994, the reliability of the tested modular switchgear is good; If δ f >5.994, the reliability of the tested modular switchgear is poor.

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