Design And Simulation Of Short Network Reactive Compensation Controller In The Electric Arc Furnace

The process of reactive power compensation in the short network of the electric arc furnace is an important part of energy-saving control technology in the ferroalloy industry.If problems such as reactive power losses in the power supply network are not solved during the operation of the electric arc furnace,the operation of the power supply network will be unstable first,and eventually the energy consumption of the electric arc furnace will increase,and the efficiency will reduce.In this paper,the structure of the short net of the arc furnace is redesigned.Firstly,the parameters of the new structure were analyzed and calculated theoretically.The negative sequence current was calculated based on the symmetric component method.The size of the thyristor trigger angle was controlled by Pulse Width Modulation(PWM),Then,the Fourier transform is applied to the collected negative sequence current,from which the fundamental wave component is extracted and the compensation current value is calculated.Finally,TCR+TSC hybrid circuit control system is adopted to reactive power compensation for negative sequence current in power supply network.The thyristor trigger angle control is completed by digital signal processor,and all data calculation is completed in digital signal processor.The design rationality of the short network is proved by simulation calculation.The hardware part mainly adopts TMS320LF2407A DSP micro-controller produced by TI company of the United States as the main control system,realizing the fast and accurate compensation of low cost reactive power.First,that voltage and current values ware collected are sent to the analog-to-digital converter(A/D)of DSP through the sampling circuit and output to the Industrial PC after A/D conversion.Then,the thyristor trigger angle is calculated by the Industrial PC and fed back to DSP.The pulse width modulation wave is emitted according to the return value.The compensation admittance is controlled by the thyristor trigger circuit and the dynamic regulation of compensation admittance is realized.The three-time spline interpolation approach method is used to determine the compensation control triggering angle,drive switching and continuously adjust the thyristor phase angle in the software part of this paper.The reactive power compensation of the short network of the electric arc furnace can be realized under the condition of no oscillations.By comparing the performance and indicator of various algorithms of the reactive power compensators in the references at the end of the thesis,we established a hybrid reactive power compensation control system with thyristor switched capacitor(TSC)as the main part and thyristor controlled reactor(TCR)as the auxiliary part.Firstly,the working principle of the system is expounded.Then,based on the Simulink of the platform software MATLAB,the compensation control function of the hardware circuit is simulated.Finally,the design and simulation of the short-network reactive compensation controller for the electric arc furnace are completed.