Nonlinear coating method based on electrophoresis self-adaptive regulation and control

Abstract

The invention relates to a nonlinear coating method based on electrophoresis self-adaptive regulation and control, which comprises the following steps of: constructing an electrophoresis system consisting of a pair of parallel polar plates and nonlinear conductive particles positioned between the polar plates, monitoring characteristic parameters in the electrophoresis process in real time, and dynamically adjusting voltage and temperature parameters in the electrophoresis process by adopting a control algorithm, therefore, while the characteristic parameters are regulated and controlled in an internal feedback mode, regulation and correction are realized in an external feedback mode according to comparison between the regulated characteristic parameters and error values, the electrophoresis process is monitored in real time, and nonlinear coating is realized. According to the invention, electrophoresis characteristic parameters are measured, and voltage and temperature parameters in electrophoresis are dynamically adjusted according to the characteristic parameters through a data acquisition and monitoring system, so that real-time monitoring and adjustment of electrophoresis quality are realized.

Description

Technical Field

[0001] The present invention relates to a technology in the field of electrical insulation, in particular to an electrophoresis adaptive control method for a nonlinear coating layer of various electrical equipment such as cable terminals, pot-type insulators and power devices. Background Art

[0002] Due to the existence of uneven electrodes and insulation structures, high-voltage power equipment is prone to local electric field distortion under external high voltage operating conditions, especially at weak locations such as metal tips or insulation interfaces. When the electric field is distorted to a certain extent, it is easy to induce local discharge or even breakdown, seriously affecting the reliable and safe operation of the power grid.

[0003] Particles with nonlinear conductivity characteristics, such as silicon carbide and zinc oxide, are arranged and distributed in an orderly manner in an insulating material under the action of electrophoretic force to prepare a nonlinear coating layer. When the electric field of the coating layer with nonlinear conductivity characteristics reaches a certain value, its conductivity will be significantly improved, thereby effectively alleviating the local electric field strength. However, the key issue is that the electrophoretic preparation process is affected by many factors, such as temperature, electric field strength, dielectric constant of the insulating matrix, material conductivity, chemical state of the particle surface, particle size and weight, etc., which may affect the particle charge properties, mobility and migration stability, etc., thereby affecting the quality of the coating layer and the subsequent electric field mitigation effect. Therefore, it is necessary to monitor and adjust the electrophoretic preparation process in real time to ensure the quality of the coating layer and the effectiveness of its electric field mitigation. At present, the electrophoretic process is mainly monitored by optical imaging and other methods, but this method is subjective in evaluating the quality of electrophoresis and cannot achieve quantitative evaluation and regulation of the electrophoretic preparation process. Summary of the invention

[0004] In view of the above-mentioned deficiencies in the prior art, the present invention proposes a nonlinear coating method based on electrophoresis adaptive control, which measures the characteristic parameters of electrophoresis and dynamically adjusts the voltage and temperature parameters in electrophoresis according to the characteristic parameter values ​​through a data acquisition and monitoring system to achieve real-time monitoring and adjustment of the electrophoresis quality.

[0005] The present invention is achieved through the following technical solutions:

[0006] The present invention relates to a nonlinear coating method based on electrophoresis adaptive regulation, which constructs an electrophoresis system consisting of a pair of parallel plates and nonlinear conductive particles located therebetween, monitors characteristic parameters in the electrophoresis process in real time, and dynamically adjusts voltage and temperature parameters in the electrophoresis process using a control algorithm, thereby regulating the characteristic parameters in an internal feedback manner, and realizing regulation correction in an external feedback manner based on the comparison between the adjusted characteristic parameters and error values, thereby monitoring the electrophoresis process in real time and realizing nonlinear coating.

[0007] The nonlinear conductive particles refer to inorganic particle materials that exhibit nonlinear conductive properties when the electric field strength reaches a certain threshold, that is, when the electric field is low, the conductivity basically does not change with the electric field, and when the electric field strength reaches a certain threshold, the conductivity increases with the increase of the electric field strength, such as zinc oxide particles, silicon carbide particles, etc., which are realized by using but not limited to the technology recorded in Chinese patent document CN117476270A (an epoxy composite material capable of accurately controlling nonlinear conductivity and its preparation method).

[0008] The characteristic parameter is the current flowing through the electrophoresis system I = λUσ, where: λ is the geometric parameter of the electrophoresis system, U is the external voltage, and σ is the conductivity of the solution in the electrophoresis system; specifically, the conductivity that changes with time σ(t)=σ0e -αt (1+βΔT(t)), the time-varying current I(t)=λU(t)σ0e -αt (1+βΔT(t)), where: σ0 is the conductivity of the solution in the electrophoresis system at t=0, α and β are the temperature coefficients of the solution conductivity, and ΔT is the change in temperature at t compared to t=0.

[0009] The internal feedback, that is, fine-tuning the particle migration rate according to the fine-tuning temperature and voltage parameters, ensures the uniform electrophoresis effect by controlling the current stability, specifically: through the Kalman filter least squares estimator and the historical characteristic parameter value, set the initial estimate r0(0), the initial covariance P(0), and for each sampling point t, update the state estimate r0(t+1)=r(t)+K(t)*(r(t)-r0(t))), where: r0(t+1) and r0(t) are the current estimation values ​​at time t+1 and t respectively, r(t) is the real-time characteristic parameter value at time t, and the gain K(t) is dynamically calculated according to the covariance matrix, specifically: P(t+1)=(1-K(t))·P(t), P(t+1) and P(t) are the covariances at time t+1 and t respectively.

[0010] The external feedback refers to: calculating the error between the real-time characteristic parameter value r(t) and the estimated value r0(t) Σ = r(t) - r0(t), and then adjusting the voltage and current applied to the electrophoresis system, specifically: U(t+1) = U(t) + γ U Σ, T(t+1)=T(t)+γ T Σ, where: γ U and γ T is the adjustment coefficient, which is used to adjust the electrophoresis characteristic parameter (i.e., current). When the error Σ is large, increase γ U and γ T To increase the adjustment rate, when the error is small, reduce γ U and γT To prevent the system from over-adjusting or oscillating.

[0011] The adjustment coefficient is preferably γ U =0.05,γ T =0.1. Technical Effects

[0012] The present invention monitors the characteristic parameters of the electrophoresis current in real time during the electrophoresis process, and the internal control loop uses a control algorithm to dynamically adjust the voltage and temperature parameters during the electrophoresis process, thereby regulating the characteristic parameters of the current. The external feedback loop compares the adjusted characteristic parameters with the error value to achieve adaptive regulation of the electrophoresis process. Compared with the prior art, the present invention can monitor and control the preparation process of the nonlinear coating layer prepared by electrophoresis for electric field relief of high-voltage power equipment in real time. In addition, the system can also assist in the optimization design of electrophoresis control parameters, and support the quantitative evaluation between electrophoresis parameters and the electric field relief effect of the nonlinear coating layer. The method provided by the present invention is applicable to various electrical equipment such as cable terminals, basin insulators and power devices, and is of great significance for improving the insulation performance of electrical equipment and improving the operational reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a flow chart of the present invention;

[0014] Figure 2 It is a schematic diagram of the electrophoresis adaptive adjustment system;

[0015] In the figure: sample to be coated 1, nonlinear conductive particles 2, high-precision ammeter 3, data acquisition card 4, monitoring system 5, DC high voltage source 6, contact temperature sensor 7, temperature controller 8, wire 9;

[0016] Figure 3 and Figure 4 It is a schematic diagram of the effect of the embodiment. DETAILED DESCRIPTION

[0017] like Figure 2 As shown, this embodiment involves a nonlinear coating system based on electrophoresis adaptive control, including: a pair of samples to be coated 1 (equivalent to parallel plates) arranged relatively to each other and nonlinear conductive particles 2 arranged therein, wherein: the samples to be coated 1 are respectively connected to the positive and negative electrodes of a DC high-voltage source 6, a high-precision ammeter 3 is further provided in the circuit, a contact temperature sensor 7 is provided on the outside of the sample to be coated 1 for measuring the current temperature and converting the temperature value into an electrical signal and outputting it to a data acquisition card 4 and a temperature controller 8 respectively, and the temperature controller compares the real-time temperature with the set temperature value to achieve temperature regulation.

[0018] like Figure 1As shown, this embodiment relates to a nonlinear coating method based on electrophoresis adaptive control, which specifically includes:

[0019] Step 1: Provide the electric field force required for the electrophoresis process through a DC high-voltage source (the initial voltage output is set to 1000V), monitor the real-time temperature of the electrophoresis system through a contact temperature sensor with a detection sensitivity of 0.1°C, and convert the temperature value into an electrical signal and transmit it to the temperature controller. The controller compares the real-time temperature with the set temperature value (the initial temperature value is set to 30°C) to achieve temperature regulation.

[0020] Step 2: The high-precision ammeter measures the current value r(t) flowing through the electrophoresis system in real time, and collects the current value through the data acquisition card. The sampling rate is set to 10s. -1 The collected current is input into the Kalman filter least squares estimator, and the initial estimate is set to r0(0) = 0.5 mA and the initial covariance P(0) = 1. For each sampling point t, the state estimate is updated: r0(t+1)=r(t)+K(t)*(r(t)-r0(t))), where: the gain K(t) is dynamically calculated based on the covariance matrix.

[0021] Step 3: Update the covariance matrix P(t+1)=(1-K(t))·P(t). Calculate the real-time characteristic parameter value r(t) and the expected value r0(t) error Σ=r(t)-r0(t) based on the estimated expected value r0(t). Adaptively adjust the applied voltage and current parameters through the feedback path of the control system: U(t+1)=U(t)+γ U Σ, T(t+1)=T(t)+γ T Σ, where: γ U and γ T is the adjustment coefficient, and the adjustment coefficient is set to γ U =0.05,γ T =0.1, thereby achieving the adjustment of electrophoresis characteristic parameters (i.e. current) and the quality monitoring of the electrophoresis process.

[0022] In this embodiment, the high-precision ammeter 3 can detect currents in the range of 2nA to 20mA, with a resolution as low as 1fA; the data acquisition card 4 has a single-channel maximum sampling rate of 48kHz; the DC high-voltage source 6 has an output voltage range of DC 0 to 3000V, with a ripple ≤0.01%.

[0023] After specific experiments, the current value and electrophoretic coating effect in the electrophoresis process when the adaptive control method is not used, and the current value and electrophoretic coating effect in the electrophoresis process after the adaptive control method is used are compared as follows:

[0024] like Figure 3As shown, (a) and (b) are the real-time current values ​​collected before and after the adaptive control method is adopted. The adaptive control method can effectively improve the current stability.

[0025] like Figure 4 (a) shows the electrophoretic coating effect before the adaptive control method is adopted. There are many residual particles in the middle, the distribution is uneven, and the coating effect is poor.

[0026] like Figure 4 (b) shows the electrophoretic coating effect after the adaptive control method is adopted. There are basically no particles remaining in the middle, and the coating effect is good.

[0027] Compared with the existing technology, the device uses the electrophoretic current in the electrophoretic process as the characteristic parameter of the electrophoretic process, and can achieve quantitative regulation compared with the more subjective optical imaging and other methods in previous technologies; through the internal control loop and the external feedback loop, the preparation process of the nonlinear coating layer prepared by electrophoresis for electric field relief of high-voltage power equipment can be monitored and controlled in real time, thereby improving the accuracy of electrophoresis regulation; in addition, the quantitative evaluation method of the system can also assist in the optimization design of electrophoresis regulation parameters.

[0028] The above-mentioned specific implementation can be partially adjusted in different ways by those skilled in the art without departing from the principle and purpose of the present invention. The protection scope of the present invention shall be based on the claims and shall not be limited by the above-mentioned specific implementation. Each implementation scheme within its scope shall be subject to the constraints of the present invention.

Claims

1. A nonlinear coating method based on electrophoresis adaptive control, characterized in that: An electrophoresis system consisting of a pair of parallel electrodes and nonlinear conductive particles therebetween is constructed. The characteristic parameters of the electrophoresis process are monitored in real time, and a control algorithm is used to dynamically adjust the voltage and temperature parameters of the electrophoresis process. The characteristic parameters are regulated by internal feedback, and adjustment and correction are achieved by external feedback based on the comparison between the adjusted characteristic parameters and the error value. The electrophoresis process is monitored in real time and nonlinear coating is achieved.

2. The nonlinear coating method based on electrophoresis adaptive control according to claim 1 is characterized in that: The characteristic parameter is the current flowing through the electrophoresis system I = λUσ, where: λ is the geometric parameter of the electrophoresis system, U is the external voltage, and σ is the conductivity of the solution in the electrophoresis system; specifically, the conductivity that changes with time σ(t) = σ0e -αt (1+βΔT(t)), the time-varying current I(t)=λU(t)σ0e -αt (1+βΔT(t)), where: σ0 is the conductivity of the solution in the electrophoresis system at t=0, α and β are the temperature coefficients of the solution conductivity, and ΔT is the change in temperature at t compared to t=0.

3. The nonlinear coating method based on electrophoresis adaptive control according to claim 1 is characterized in that: The internal feedback, that is, fine-tuning the particle migration rate according to the fine-tuning temperature and voltage parameters, ensures a uniform electrophoresis effect by controlling the current stability, specifically: setting the initial estimate r0(0) and the initial covariance P(0) through the Kalman filter least squares estimator and the historical characteristic parameter value, and updating the state estimate r0(t+1)=r(t)+K(t)*(r(t)-r0(t))) for each sampling point t, wherein: r0(t+1) and r0(t) are the current estimates at time t+1 and t, respectively, r(t) is the real-time characteristic parameter value at time t, and the gain K(t) is dynamically calculated according to the covariance matrix, specifically: P(t+1)=(1-K(t))·P(t), P(t+1) and P(t) are the covariances at time t+1 and t, respectively.

4. The nonlinear coating method based on electrophoresis adaptive control according to claim 1 is characterized in that: The external feedback refers to: calculating the error between the real-time characteristic parameter value r(t) and the estimated value r0(t) Σ = r(t) - r0(t), and then adjusting the voltage and current applied to the electrophoresis system, specifically: U(t+1) = U(t) + γ U Σ, T(t+1)=T(t)+γ T Σ, where: γ U and γ T is the adjustment coefficient, which is used to adjust the electrophoresis characteristic parameter (i.e., current). When the error Σ is large, increase γ U and γ T To increase the adjustment rate, when the error is small, reduce γ U and γ T To prevent the system from over-adjusting or oscillating.

5. The nonlinear coating method based on electrophoresis adaptive control according to claim 4 is characterized in that: The adjustment coefficient is γ U =0.05,γ T =0.1.

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