Zong Xiju

LCL in parallel active power filter of SVPWM control

Although the traditional active power filter, which is in the grid side using the single inductance L as output filter, can be used to improve the quality of the power, the high frequency ripple suppression effect of them is less than ideal. In order to improve the high frequency ripple suppression capacity, in this paper, we propose a topology of the LCL filter paralleling to the grid side, and SVPWM tracking control algorithm is used to improve the tracking performance of active power filter. By constructing Lyapunov function, the stability of the LCL in parallel active power filter is analyzed, and the simulation and experimental results show that APF using LCL as output filter, can suppress the high frequency ripple, and the supperession effect can be improved.

Design of ARM-based Reactive Power Compensator with Time Variable Limits

In this paper, ARM-based reactive power compensator with time variable limits is presented. In order to improve the performance of compensator, ARM is used as processor. The traditional A/D module acquisition has many disadvantages, so the acquisition is implemented by supervisory control and data acquisition (SCADA). The acquired data is transmitted to the compensator by DM9000A network control chip. According to the load level, the whole time intervals in a day are divided into multi-time intervals by fractal and clustering algorithms with the constraints of the maximum allowable daily operating times (MADOT) of transformer or capacitor. The optimal node reactive power ( opt Q ) and the optimal node voltage ( opt U ) of each intervals are calculated by Optimal Power Flow (OPF) algorithm, and then the lower and upper limits of voltages and VARs of time intervals are calculated by voltage step of the transformer, capacity of the capacitor, the time intervals and the grid optimal data. According to the real-time voltage and reactive power and the nine-zone criterion with the new limits, ARM determines which zone the operating point is located in, and then the corresponding compensation scheme is operated. The compensator changes the transformer taps or switched on/off capacitors by I/O extended module. The experimental result shows that the number of operations is reduced. Moreover, the service life of transformers and capacitors are prolonged.

Stabilization of the degasperis-procesi equation with periodic boundary condition

In this paper, we shall study the stabilizability of the Degasperis-Procesi (D-P) equation with periodic boundary condition, namely, by linear distributed feedbacks. First, by using the multiplier technique, we show that the solution to the D-P equation with the distributed feedback control is asymptotically stable. Secondly, by using T. Katopsilas theorem, we show the closed-loop system under a distributed feedback control is locally well-posed. Finally, by taking account into the energy estimates, we draw a conclusion that the closed-loop system is in fact globally well-posed. The proof is based on a remarkable property of this equation: the existence of an infinite sequence of conservation laws corresponding to an infinite sequence of useful multipliers.