Study Of Active Power Filter For Harmonic Suppression And Reactive Power Compensation Of Warship

The rapid development of the power electronics has improved the life-force and battle effectiveness of warship. However, the increasing use of power electronic devices causes large amounts of harmonics and reactive current injecting into warship power system, affects the power quality of warship power system seriously, and threatens the security, stability and reliability of the system greatly. Analyzing the specific conditions and environmental characteristics of warship, shunt Active Power Filter (APF) is used to dynamically suppress harmonics and compensate reactive power of warship power system.The reasons for the harmonic and reactive power generated by warship power system are described and the feasibility of harmonic suppression and reactive power compensation with shunt APF is analyzed in this paper. Then the principles of shunt APF are introduced and the mathematical model of three-phase three-wire shunt APF is established. A common detection algorithm of harmonic and reactive current--the ip-iq method based on the instantaneous reactive power theory is discussed. The Phase Locked Loop of traditional ip-iq method is modified by Single Synchronous Reference Frame-Software Phase-Locked Loop (SSRF-SPLL) and Decoupled Double Synchronous Reference Frame-Software Phase Locked Loop (DDSRF-SPLL). On the basis of theoretical analysis, simulations of SSRF-SPLL and DDSRF-SPLL with Matlab/simulink plateform are used to analyze the quality of phase-tracking under the conditions of ideal voltages, distorted voltages, mutational frequency and unbalanced voltages. Meanwhile, simulations of the ip-iq method based on SSRF-SPLL and DDSRF-SPLL are used to analyze the detection performance. A Space Vector Pusle Width Modulation (SVPWM) current control strategy based on voltage feedforward and P controller is designed. The results of simulation prove that the proposed control strategy has a good tracking performance under the condition of a symmetric load, mutational load and asymmetric load.A three-phase three-wire shunt APF prototype based on DSP28335is designed and built for experimental study to verify the accuracy of the ip-iq method based on DDSRF-SPLL, and validate the feasibility of the proposed control strategy under the conditions of a symmetric load, mutational load and asymmetric load. The performance of the designed APF for harmonic suppression and reactive power compensation is good.