Research On Unified Power Quality Conditioner Technology Based On Super Capacitor Energy Storage

Currently, the demand for emergency power supply system and mobile powersupply system is increasing, diesel generator set are widely applicated in the abovetwo systems due to its easy-to-move, strong adaptability to environment, highreliability, controllable energy supply etc. However, in some special applications，which require higher power quality, diesel generator sets’ feature of the soft outputvoltage is difficult to meet the requirements. In order to optimize the dynamic outputpower quality of the diesel generator sets and to improve its operating effic iency,this paper focuses on the study of unified power conditioner technology, which isbased on the super capacitor energy storage.Firstly, this paper builds the mathematical model of diesel generatorindependent power system including diesel engine and its control system,synchronous generator as well as excitation system, which derives the expression ofoutput voltage transient time-domain in the step load disturbance, reveales thenature reason of the output voltage dynamic drop, and lays a theoretical foundationfor follow-up research on optimizing the performance of the dynamic output of thediesel generator set and improving its operating efficiency.Secondly, a unified power quality conditioner for diesel generator set withstorage link is proposed, further more, the corresponding control strategy combiningthe reactive power compensation, e index based dynamic active powercompensation and active filter technology is proposed. At the same time, the Innercurrent loop vector control for power quality conditioning system, phase-lockedloop technology is in-depth studied, and proposed the DC side energy storage supercapacitor energy management strategies and flexible charging current controlstrategy to build a complete power quality conditioner systems.Finally, on the basis of theoretical analysis, this paper design the keyparameters of the super capacitor’s capacitance and filter inductor and obtain thedesign principles. Using MATLAB/SIMULINK to build the simulation model of thesystem, carry out a detailed simulation study of the proposed control scheme and theresults of theoretical analysis. The results of simulation show that, the proposedpower quality conditioning system has good control performance, diesel generatorset’s overall performance can be markedly improved, which is close to the outputfeature of public power grid. And a low-power experimental platform was built,the experimental results verify the correctness and feasibility of proposed schemeand control strategies.