CN-122017542-A - Switch cabinet conductor temperature rise budget system and method thereof

CN122017542ACN 122017542 ACN122017542 ACN 122017542ACN-122017542-A

Abstract

The invention discloses a switch cabinet conductor temperature rise budget system and a method thereof, which belong to the technical field of switch equipment conductor temperature rise state evaluation and are applicable to 3.6-40.5kV alternating current metal closed switch equipment. The method comprises the following steps of data acquisition, data preprocessing, temperature rise budget model construction and temperature rise budget result output. By the high-precision switch cabinet conductor temperature rise budget system and the high-precision switch cabinet conductor temperature rise budget method, the problems of inaccurate early warning caused by incomplete parameter coverage in a traditional system can be solved by comprehensively considering multiple parameters such as load current, running time, ambient temperature and humidity, plum blossom contact temperature, plum blossom contact insertion depth, spring holding force and the like.

Inventors

ZHENG SHIRUI
LIU ZHIYUAN
LI PEIZHONG
Lv kai
WANG XINJUN
ZHAO CHUNYU
Guo Shifa
LU HONGSHEN
ZHAI QINGYU
NIE SHENGDONG

Assignees

山东泰开成套电器有限公司

Dates

Publication Date: 20260512
Application Date: 20251229

Claims (9)

1. The temperature rise budget system for the conductors of the switch cabinet is characterized by comprising the following modules: The data acquisition module is used for acquiring load current I (T), running time T, ambient temperature T1 (T), relative humidity RH (T), tulip contact temperature T2 (T), tulip contact insertion depth h (T) and spring holding force F (T); The data processing module is used for carrying out outlier rejection and standardization processing on the acquired data, and calculating a contact resistance R (t), a corrected conductor body resistance R (t) and a heat dissipation coefficient h (t); the model operation module is used for constructing a temperature rise budget model and solving the conductor temperature rise; and the output module is used for outputting the budget result and the overtemperature early warning signal and uploading the related result and signal to the background monitoring system by the integrated communication interface.
2. The switch cabinet conductor temperature rise budget system according to claim 1, wherein the data processing module adopts an MCU microcontroller, the model operation module adopts an FPGA chip, the output module adopts a man-machine interaction touch screen and an alarm, and the communication interface adopts a Lora module, a Wifi module or a BCNet module.
3. A method for budgeting the temperature rise of a conductor of a switchgear, characterized in that it is implemented with the system for budgeting the temperature rise of a conductor of a switchgear according to claim 1, comprising the steps of: Step one, data acquisition; collecting load current I (T), running time T, ambient temperature T1 (T), relative humidity RH (T), tulip contact temperature T2 (T), tulip contact insertion depth h (T) and spring holding force F (T) of a high-voltage switch cabinet conductor, and obtaining material characteristic parameters, structural parameters and heat dissipation characteristic parameters of the conductor; step two, data preprocessing; Performing outlier rejection and standardization processing on the acquired data, calculating a contact resistance R (T) based on a plum blossom contact insertion depth h (T) and a spring holding force F (T), correcting a conductor body resistance R (T) by combining an environment temperature T1 (T), correcting a conductor surface heat dissipation coefficient h (T) by combining a relative humidity RH (T), and calculating an actual Wen Sheng T1 (T) by combining the environment temperature T1 (T) and a plum blossom contact temperature T2 (T), wherein the temperature rise is an allowable temperature rise threshold; step three, constructing a temperature rise budget model; Based on a heat balance theory, a heat balance equation is established by combining heating power P (T) and radiating power Q (T), and a Euler iteration method is adopted to solve conductor real-time temperature T (T), so that conductor temperature rise delta T2 (T) =T (T) -T2 (T) is obtained; Step four, outputting a temperature rise budgeting result; And comparing the conductor Wen Sheng T2 (T) obtained by budget with the temperature rise delta T1 (T) of the actual conductor, and outputting a budget result and an overtemperature early warning signal.
4. The method for budget temperature rise of a switch cabinet conductor according to claim 3, wherein in the step of data collection, a current transformer is used for collecting the load current I (t), and the current transformer can be integrated in an all-in-one sensor or can be an independent primary current transformer on the switch cabinet or can be a Hall current sensor for monitoring the secondary side current of the current transformer; The temperature and humidity sensor is used for collecting the ambient temperature T1 (T) and the relative humidity RH (T), the all-in-one sensor is used for collecting the temperature T2 (T) of the plum blossom contact, and the sensor is deployed at the top position far away from the heating source in the switch cabinet; a distance measuring sensor is adopted to collect the insertion depth h (t) of the plum blossom contact, the measuring precision is +/-1 mm, and the resolution is 0.1mm; And collecting the clamping force F (t) of the quincuncial contact spring by adopting a pressure sensor, wherein the measuring range is 0-500N.
5. The method for budget temperature increase for a switchgear conductor according to claim 3, wherein in the step of data preprocessing, an empirical formula of the contact resistance R (t) is: R1(t)=K/[n*F(t)*h(t)/h] wherein K is a contact material coefficient, h is a standard insertion depth of the tulip contact, n is a contact form coefficient, and n=1 for the tulip contact.
6. The method for budget temperature increase of a switchgear conductor according to claim 3, wherein in the step of data preprocessing, a correction formula of the conductor body resistance R (t) is: R2(t)=ρ*L*[1+α(T2(t)-20)]/S where ρ is the resistivity of the conductor at 20 ℃, L is the conductor length, α is the conductor temperature coefficient, and S is the conductor cross-sectional area.
7. The method for budget temperature increase of a switchgear conductor according to claim 3, wherein in the step of preprocessing the data, an empirical correction formula of a conductor surface heat dissipation coefficient h (t) is: h(t)=h*[1-0.01*(RH(t)-50)] where h is the heat dissipation coefficient at standard humidity rh=50%.
8. The method for budget temperature increase of a switchgear conductor according to claim 3, wherein in the step of constructing the budget temperature increase model, a calculation formula of the heating power P (t) is: P(t)=I(t)2*[R1(t)+R2(t)] the empirical calculation formula of the heat dissipation power Q (t) is: Q (T) =h (T) ×a [ T2 end (T) -T2 primary (0) ]+ε×σ×a [ T2 end (T) -T2 primary (0) ] Wherein A is the conductor heat dissipation area, epsilon is the conductor surface emissivity, sigma is the blackbody radiation constant, T2 primary (0) is the temperature of the conductor at the initial moment, and T2 tail (T) is the temperature of the conductor after T time.
9. The method for budget temperature increase of a switchgear conductor according to claim 3, wherein in the step of constructing the budget temperature increase model, a thermal equilibrium equation is: C*m*dT2(t)/dt =P(t)-Q(t) Solving by adopting an Euler iteration method, wherein the iteration formula is as follows: T(t+Δt)=T2(t)+[P(t)-Q(t)]*Δt/(C*m) Wherein, C is the specific heat capacity of the conductor, m is the mass of the conductor, Δt is the iteration step length, the value is 0.1, and the initial condition T (0) =T2 (0); Further, the conductor temperature rise delta T2 (T) =T (T) -T2 (T) is obtained; The actual Wen Sheng T1 (T) is calculated by combining the ambient temperature T1 (T) and the tulip contact temperature T2 (T), the temperature rise is an allowable temperature rise threshold, namely delta T1 (T) =T2 (T) -T1 (T), And comparing the conductor Wen Sheng T2 (T) obtained through budget with the temperature rise delta T1 (T) of the actual conductor, outputting a budget result and an overtemperature early warning signal, and outputting an alarm-free signal if the difference is less than or equal to 8K according to experience.

Description

Switch cabinet conductor temperature rise budget system and method thereof Technical Field The invention relates to the technical field of switch equipment conductor temperature rise state evaluation, in particular to a switch cabinet conductor temperature rise budget system and a switch cabinet conductor temperature rise budget method, which are particularly suitable for 3.6-40.5kV alternating current metal closed switch equipment and provide core technical support for state maintenance of intelligent substations. Background The high-voltage switch cabinet is used as a switch and control equipment widely applied in a power system, the operation reliability of the high-voltage switch cabinet is directly related to the safety and stability of a power grid, the conductor temperature rise is one of core indexes for measuring the operation state of the high-voltage switch cabinet, and when the conductor temperature rise exceeds an allowable threshold, serious faults such as the reduction of the insulation performance of the conductor, the increase of contact resistance, even the initiation of arc discharge, the burning of equipment and the like can be caused. The prior art has the following problems in the budgeting system and method for the temperature rise of the high-voltage switch cabinet conductor: The temperature rise can not be early warned, namely the overtemperature warning is carried out only by depending on two parameters of the temperature of a measuring point and the ambient temperature, key factors such as load current, running time, ambient humidity, the insertion depth of a plum blossom contact, spring holding force and the like are completely ignored, and the temperature rise early warning can not be realized; the contact state is not quantized, namely, the plum blossom contact is used as a conductive connection core component, the contact area is reduced due to insufficient insertion depth, the contact pressure is reduced due to attenuation of the holding force of a spring, and the contact resistance is increased due to both the spring and the holding force, but the factor is not considered by the conventional algorithm model; the influence of the humidity on the environment is lost, namely the heat dissipation efficiency of the surface of a conductor is reduced when the humidity is increased, the temperature rise is increased in a nonlinear way when long-term heat accumulation is caused, and the influence of the factor is not considered in the existing algorithm model; The early warning is inaccurate, and the error of the existing algorithm model is usually more than 15% due to the incomplete coverage of the monitoring parameters, so that the temperature rise early warning guidance can not be provided for the operation and maintenance. Disclosure of Invention The invention aims to provide a high-precision temperature rise budget method for a switch cabinet conductor, which can comprehensively consider multi-parameter fusion such as load current, running time, environment temperature and humidity, plum blossom contact temperature, plum blossom contact insertion depth, spring holding force and the like, and solves the problem of inaccurate temperature rise early warning caused by incomplete monitoring parameter coverage in the traditional method. In order to achieve the purpose, the invention discloses a method for budget increase of conductor temperature of a switch cabinet, which is applicable to 3.6-40.5kV alternating current metal-enclosed switchgear and comprises the following steps: Step one, data acquisition; the key parameters of the conductor operation of the high-voltage switch cabinet are collected, and the key parameters specifically comprise: The electric parameters are that the current transformer collects the real-time load current I (t) of the conductor and records the continuous running time t of the current; The environmental parameters are that the real-time environmental temperature T1 (T) and the relative humidity RH (T) in the switch cabinet are acquired through a temperature and humidity sensor, and the temperature and humidity sensor is deployed at the top position, far away from the heating source, in the switch cabinet; the contact parameters are that the real-time insertion depth h (T) of the plum blossom contact is collected through a ranging sensor, the ranging sensor is fixed on the side face of a contact mounting seat, the measuring precision is +/-1 mm, and the resolution is 0.1mm; collecting real-time holding force F (T) of the plum blossom contact spring through a pressure sensor, embedding the pressure sensor into a spring fixed end, and measuring the measuring range by 0-500N, collecting real-time temperature T2 (T) of the plum blossom contact through a temperature sensor, wherein the measuring precision is +/-2 ℃; Basic parameters include a material characteristic parameter (copper conductor resistivity ρ=1.72X -8 Ω·m, temperature coefficient α= 0.00393/°c),