Study On Electromagnetic Vibration Of A Magnetron-saturated Reactor Considering Magnetic Stretching Effect

In the power system,controllable saturable reactor(CSR)can compensate the reactive power.But the vibration and noise caused by the reactor not only have a bad influence on the surroundings,but also damage the performance of the reactor.Moreover,it will do harm to the operation of the entire power gird stability and efficiency.In order to lower the electromagnetic vibration and noise that caused by the reactor core,numerical analysis of the source of electromagnetic vibration was carried out.That is,the electromagnetic vibration was analyzed that takes magnetostrictive effect of laminated iron core into account.Controllable saturable reactor can adjust the degree of saturation by the control current value and permeability.So the reactive power of CSR can be adjust continuous.But,at the same time,there will be a DC bias which will aggravate the electromagnetic vibration.So,it has a great theoretical and practical significance to study the electromagnetic vibration of the reactor caused by the magnetostrictive effect of the laminated core under different saturate degrees.And in this paper,the damping effect of silicon steel sheet was taken into account to analysis the influence of electromagnetic vibration.The main contents of this paper are as follows:Firstly,in order to simulate the magnetic characteristics of the iron core silicon steel sheets under different saturation conditions,the magnetization characteristic curve and magnetostrictive characteristic curve were measured under different control current.In this paper,the DC magnetic flux was taken into account.Magnetization and magnetostrictive characteristic was measured by the Epstein 700 and magnetostrictive measurement system MST500 that was produced by Germany.In order to make the magnetic characteristic curve can apply to numerical analysis,the curve measured were processed into single value curve.Then,based on the Maxwell’s equation and Elastic mechanics equation,the numerical analysis model of magnetic field and the mechanical vibration field of reactor were carried out.By using COMSOL Multiphysics,a three-dimensional numerical model of CSR was established considering magnetostrictive effect and damping effect of laminated core.Damping effect can be reflected by the modal analysis.Through the modal analysis,the damping coupled coefficient can be determined by the first six frequency.And then,the single-value magnetization and magnetostrictive curve were coupled to numerical analysis software.The distribution and magnitude of magnetic field and vibration signal of CSR were calculated and analyzed under different control currents.Finally,for a 4.4kVar/220V CSR prototype of numerical analysis,the vibration test was completed under different control currents.The vibration acceleration magnitude was measured and analyzed under different DC control current level.Then,the measurement results and analysis results were compared.