Advanced Materials Research Vols. 354-355

Abstract: Monocyclic phenolic compounds (MCPCs) from petroleum and coal sources mainly include phenol, cresols, and xylenols. A newly isolated 2,3-xylenol-degrading strain, Pseudomonas sp. XQ23, was found to be capable of degrading up to 10 MCPCs for the first time. Addition of easy-to-degrade MCPCs such as phenol and cresols helped decompose hard-to-degrade xylenols and the sequential digestion of the phenolic substrates was highly dependent on their molecule structures. The action on multiple MCPCs by the new isolate XQ23 from this work revealed useful clues on the co-biodegradation of multiple pollutants.

Abstract: Hysteresis current controllers are widely used in PV inverters. The main drawback of conventional hysteresis current control is that the switching frequency is variable, as the hysteresis band is fixed. In this paper an adaptive band hysteresis control algorithm with no derivative calculation is presented. As it will be shown, this algorithm can limit the switching frequency variation within a small range and the algorithm itself is simple and easy to be implemented. The performance of this algorithm, together with the one [10] and conventional hysteresis control has been evaluated by means of simulations performed with PSIM and SIMULINK. Simulation results show the effectiveness of the suggested hysteresis current controller.

Abstract: Based on the mathematical model of the wind power grid-connected inverter, the proposed space vector PWM current control and double current control realize the decoupling for the current active component and reactive component. The simulation results show that the system can output three phase sine current which meet the requirement of the gird-connected, and the harmonic component is low.

Abstract: Power electronic transformer (PET) which has a big potential application value in smart grid is an electrical power transformer device adopting power electronic converter and high frequency switch transformer. A new PET with power factor correctors (PFC) is proposed in this paper. Due to high power level of PET, PFC should have a high power level as well. Therefore, the multi-phase interleaved PFC is employed. The paper describes the one cycle control principle, proposes a current synthesis method based on IGBT current, and then analyses the relationship between ripple current and duty cycle of IGBT. In addition, the whole PFC system is simulated completely by means of Matlab/Simulink. In order to verify the theoretical analysis and simulation analysis, a four-phase interleaved PFC with a rated output power of 8.0kW is designed and implemented based on the an analog control chip. The obtained results show that the interleaved PFC by means of one cycle control and current synthesis is feasible, capable of reaching a good suppression effect of ripple current.

Abstract: Matrix rectifier (AC-DC MC) is a four-quadrant AC-DC power converter device with compact topology. This paper concerns the influence of abnormal power supply conditions to the matrix rectifier. The input and output performances of matrix rectifier with pure sinusoidal supply voltages are discussed. The input currents are symmetrical sinusoidal without any low-order components. But due to the absence of DC capacitors, the abnormal conditions at input side affect the input and output performances directly, which introduce ripples into the DC output and cause the distortion of input currents. In this paper, the low-order harmonic components in input currents, and ripples at output side are theoretically analyzed under conditions that the input voltages are unbalanced and non-sinusoidal respectively. The simulation research is carried out to verify the theoretical analysis, and the results, which demonstrated the analysis conclusions, are given.

Abstract: A new frequency conversion device topology based on matrix rectifier and AC chopper called MCAC） is proposed, which is referred as AC chopper matrix converters. First, the basic configuration of these new topologies and the fundamental principle are introduced. Then, the validity and feasibility of the new topologies are tested by digital simulation and prototype experiments. The results indicate that the output voltage transfer ratio can be larger than 1.0, the output voltage waveform is very close to standard sine wave and the harmonic contents increase slightly, overcoming the drawbacks of conventional MCs that maximum voltage transfer ratio is 0.866. This study may provide inspiration for further engineering applications.

Abstract: This paper proposed a single stage inverter for PhotoVoltaic(PV). The inverter is a push-pull forward converter employed synchronous rectifier technique. The push-pull forward converter is used to convert the photovoltaic battery output voltage into high frequency SPWM square wave, and the rectifier circuit is used to change the polarity of the isolation high frequency transformer output SPWM wave. For improve performance of the inverter in both the command tracking and the load disturbance regulation, a PID control strategy is realized by using the TMS320LF28335 DSP. Theoretical analysis and experimental results indicate that the proposed topology and control scheme are promising for the applications of PV power supply.

Abstract: Interleaving Parallel is the unique technology with the combination of SPWM modulation technology with multiple technology. This paper was researched the interleaving parallel rectifier technology in restraining the AC side current ripple in detail, and compared current ripple in the AC side between the single rectifier and the interleaving parallel rectifier. The research was deduced that current ripple in the AC side of the interleaving parallel rectifier was lessened than the same parameters of the single rectifier. The relevant simulations were verified the characteristic of restraining the current ripple in the AC side in interleaving High-Frequency rectifier was effective.

Abstract: In this paper, the pulse width modulation based on double reference signals is proposed for diode neutral point clamped tri-lever rectifier. In this method, the angle of non-switching region is chosen to make switching losses minimum, and DC voltage utilization is improved. The simulating results show that proposed strategies are correct.

Abstract: A complete direct-driving wind power system consisting of wind turbine, permanent-magnet synchronous generator, multilevel matrix converter with voltage space vector modulation strategy is proposed in this paper. The simulation model is set up through Matlab/Simulink, and the results have verified the control strategy is feasible. Multilevel matrix converters are suitable for high- voltage application of wind power generation system, and it has laid a good basis for the real system development.