Research On Reactive Power Compensation And Harmonic Suppression With High Cost Performance

As for special goods, power quality becomes more and more concerned by persons. And power quality of distribution network has more close relation to us. AC converter and TSF that combine power electronic technology, digital signal processing and advance control theory has high cost performance on reactive power compensation and harmonic suppression. In this thesis, it does deep research on key technologies of AC converter and TSF to enlarge its application rage, such as, topology of AC converter, switch control strategy, choice for reference of hardware, harmonic and reactive current detection, control of output current, structure and control design for the whole system, and so on.Through analysis traditional topology of AC converter, a lower cost one is chosen which needn't extra snubbers. And it has already existed switch control principle based on voltage detection. However, once detection of direction becomes wrong, it will be short-through, which will cause big damage. Unluckily, situation of detection wrong couldn't be avoided. So it is quite important to put up a new way to solve the problem. Paper implies current detection principle that can run well. And as if wrong detection happens, it just appears open. Then, snubbers could be inserted to make the circuit work continuously. What's more, working time for snubbers is quite short, which leads to little cost. Different work states for the whole circuit are introduced in details in the thesis. In additional, simulation and experiment also are done.Detection of reactive and harmonic current plays an important role in compensation and suppression. Through study on former way, we find LPF is quite common use in each method. Then, a better LPF is designed for detection. And simulation is done in the thesis to show its good performance.Reference of hardware also has big impacts on effects of reactive power current compensation and harmonic current suppression. Paper does the comparisons about output current waveforms and THD between different references (such as, frequency of switch, D, LC) to ensure the analysis through MATLAB simulation.To solve the problem of extensive calculation and complex control technique, a new control principle based on instantaneous current is put forward. PI control way has easy calculation and fast reaction. And good effect could be seen clearly through simulation.In final, we get the conclusion that it will be a trend using mixed STATCOM and TSF in the reactive current compensation and harmonic current suppression. Paper uses AC converter and TSF together to compensate and suppress, also puts up the control of the whole system, TSF does the main role in compensation, and AC converter helps it. Also, simulation and experiment have been done.