Research On One Cycle Control Strategy Of Active Power Filter

As the most widely used one of the secondary energy on today’s society, the amount of electricity consumption is staggering. The problems about power quality have appeared with the electrical energy widely used in various fields, especially harmonic pollution. A large number of non-linear loads and power electronic device were applicated, so that the serious distortion of the voltage and current of the power system is apparing, the normal operation of the power grid is threatened seriously, and even cause incalculable economic losses. The governance of energy pollution is imminent. For many years the experts at home and abroad efforts to research, active power filter (APF) for harmonic suppression has become an effective way of harmonic control, as a new kind of compensation measures, it has broad market prospects and is a hot research field of harmonic control.Based on three phase three wire system shunt active power filter, an intensive study on the basic working principle and control system is made in the paper, and focus on the two key technology of active power filter system, which is harmonic detection technology and tracking control strategy. Then a simulation is done in MATLAB software simulation environment, as the basis for guiding, the software and hardware of the APF system is designed and the experimental platform is built. The main research contents are as follows:The operating principle of active power filter is introduced, and the characteristics and application of a variety of active power filter are also described. The selected ip-iq harmonic detection technology and one cycle control technology are also highlighted, and the mathematical model of active power filter based on one-cycle control was derived.In the MATLAB simulation platform, one-cycle control mode of the APF system is built and the system parameters are set. The simulation model is simulated respectively on condition that steady loads and dynamic loads. Simulation results show that, under the condition of two kinds of negative load compensation effect is good, which illustrates the ip-iq harmonic detection technology and one-cycle control technology are feasible.The hardware platform of APF system is built, and signal detection and conditioning modules, operator control modules, intelligent power module and its drive circuit are introduced in detail. The parameter of smoothing reactor and DC side capacitance is calculated and set. Finally, the circuit debugging and precision calibration of each module are completed.In the CCS development environment the software of APF system is design, following the principles of modular design and using C language, the main program and its initialization program, interrupt capture program, and each subroutines (including A/D sampling subroutine, the Butterworth filter subroutine, harmonic calculation subroutine and compensation to control subroutine) are written. Software debugging is done on APF system hardware platform software, and the APF system filtering is accomplished. The finally obtained experimental results showed that, in the case of steady state load the APF system of one-cycle control get good compensation effect, in the case of mutation load, mutation harmonic current can be well compensated by APF system.