Simulation Analysis And Optimization Of Manganin Shunt For Smart Meter In Power Frequency Magnetic Field

Manganin shunt are widely used in current measurement due to their small temperature coefficient and low cost.As the key component of the single-phase energy meter current sampling circuit,the accuracy of current sampling of the manganin shunt will directly affect the metering accuracy of the meter.In practical applications,the electric energy meter is extremely susceptible to the interference of the power frequency magnetic field,so that the sampling end of the shunt generates an induced electromotive force,thereby seriously affecting the accuracy of the electric current meter current sampling.In this paper,the manganin shunt of single-phase energy meter is taken as the research object.The electromagnetic simulation model,the approximate modeling of the induced current and the optimization design are studied in depth to reduce the influence of the power frequency magnetic field on the induced current of the manganin shunt.Firstly,the simulation analysis method of induction current of Manganin shunt under the action of power frequency magnetic field is studied.Based on the theory of electromagnetic induction,the theoretical calculation and simulation analysis of the induced current of a regular conductor under a power frequency magnetic field is performed.The method is used as a reference for the subsequent shunt simulation.The Flux software is used to establish the electromagnetic simulation model of the shunt,and the power frequency magnetic field is obtained.The influence of the position of the via hole on the induced current;the Helmholtz coil is used to generate the power frequency magnetic field,and the relationship between the position of the shunt via hole and the induced current is tested,and the experimental verification of the simulation result is realized.Secondly,based on the simulation model,the influence of the shunt size parameters on the induced current is studied,the key dimension parameters are determined,and an approximate model is established to realize the fast calculation of the induced current.The single factor method was used to analyze the influence of various size parameters on the induced current,and then the orthogonal test design was used for multi-factor analysis to determine the critical dimension parameters of the shunt.Based on the kriging and radial basis,a rapid calculation model of the induced current is established.Through the error comparison,the radial basis model is finally determined as a fast calculation model of the induced current.Thirdly,based on the Taguchi method,the multi-objective robustness parameter design of Manganin shunt was performed.The key dimension parameters are used as controllable factors and design tolerances are taken as error factors.The test design scheme is constructed by the internal and external table direct product method.The induced currents are quickly calculated by the RBF approximation model,and the four groups are determined by the analysis of signal-to-noise ratio variance and the comprehensive balance method.Experimental program.Orthogonal tables are used to design the four groups of designs.Finally,the optimal level combination of design parameters is obtained by comparing the mean value and the standard deviation.Finally,based on the particle swarm algorithm,the manganin shunt was further optimized globally.A global optimization model of manganin shunt was established based on the RBF approximation model.The multi-objective particle swarm optimization algorithm was used to solve the model and the optimized design parameters were obtained.Comparing the optimization results of Taguchi method and particle swarm optimization algorithm,the effectiveness of particle swarm optimization in the multi-objective optimization design of the shunt is verified.