Building Electrical Harmonic Detection And Suppression Research

With the rapid development of automation technology used in building electrical engineering,the problem of harmonic pollution has become increasingly seriously.It not only affects people’s daily life,but also threatens people’s personal and property safety.In the case of severely exceeded harmonics,it will not only cause a drop in the power quality,but also will lead to a reduction in the power factor.Therefore,how to detect and suppress harmonics in building electrical has become a hot research topic recently.It is well known that there are many single-phase loads in the building electrical systems,and the single-phase loads are more easily to cause the three-phase unbalance voltages,which are not symmetrical,therefore the ip-iq detection method cannot be used directly to detect the harmonic currents effectively.In addition,the presence of a low-pass filter will also delay the detected harmonic current.Taking into account all those mentioned above,based on the theory of ip-iq detection method,this paper proposes an improved detection method by replacing the phase-locked loop PLL with the same sine and cosine signals as the signle phase voltage,meanwhile by using the average module instead of the low-pass filter,so as to realize one accurate and real-ime harmonic detection.The harmonic suppression for building electrical systems is carried out with the introduction of active power filter(APF).Based on the research on the APF control method,this paper selects the voltage space vector pulse width modulation(SVPWM)method to control the switching of those switches in the APF main circuit.Moreover,through the design of the double closed-loop PI controller,the smooth charging of the APF DC side capacitor and the stability of the main circuit voltage can be realized,so that the harmonic current can be quickly tracked.Considering the particularities of the building electrical systems,the effectiveness of the proposed harmonic detection and suppression methods are verified through the use of Simulink simulation software.Furthermore,the hardware design about the APF control system are also carried out based on the use of DSP,including the parameter selection of the APF main circuit,the the power and reset circuits,the voltage and current regulaiton circuits,the driving circuits and so on.