The Simulation Of Active Power Filter System And Realization Of The RLS Algorithm Based On DSP

With the wide application of electric & electronic devices in power system, power quality problems have already become a serious problem to which both suppliers and users of electricity have paid close attention.Active power filter(APF) is one of the effective measurements to mitigate harmonic problem and improve power quality The APF system is studied and simulated in this paper on the basis of the APF principle.And the harmonic current is detected by applying the recusive least-squares (RLS) algorithm based on the DSP -- TMS320F240.First of all,the harmonic detecting method based on RLS algorithm is discussed. Then two new improved RLS algorithm are introduced.In the paper,the Matlab simulation results show that the improved RLS algorithm can ensure a high detecting precision and provide a fast dynamic response,by simulating the single-phase circuit, which satisfy the demond of real time tracing and detection.Also the simulation results have verified the effectiveness and practicability of the new algorithm in the situations of the 3-phase symmetrical current,the 3-phase dissymmetrical current and the 3-Phase 4-wire system.Secondly,the shunt voltage APF system is simulated.Compensated current is tracked by applying the time-coatrol instantaneous comparison method and the whole simulating system is realized by means of detecting the current of the load.The simulation results show that dynamic compensation can be achieved in the situation of 3-phase symmetrical circuit and the 3-phase dissymmetrical circuit.Finally,the two detection algorithms that are the normalized RLS algorithm and the new improved RLS algorithm are realized by applying assemble language on the basis of DSP respectively By comparing the two initial converging speeds and the real-time properties of the fast transient responses,the experiment results show that the improved RLS algorithm is much better than the normalized one in the two respects.