Advanced Materials Research Vols. 516-517

Abstract: In this paper, the conventional method to acquire Thevenin equivalent parameters is described. The method is based on features of power systems and utilizes the base-case system information. Considering the impact of loads on Thevenin equivalent potential and impedance, this paper makes improvements and brings it closer to the actual situation. The necessary condition about limit power transmission is derived, and the impedance modulus margin can be used to determine voltage stability of power system. Finally, the results of IEEE-14 bus system calculations show effectiveness of the method.

Abstract: The design of a scanning magnet power-supply used in a 10MeV industrial radiation accelerator is presented in this paper. The consideration of linear magnetic field current and the principle of triangle wave modulator are included. In addition, the control system based on single chip and its anti-jamming scheme in industrial circumstance are also introduced. The scanning magnet power-supply can produce continuous triangle waveform current. The frequency can be adjusted by step length of 1Hz ranged from 20Hz to 50Hz, and the peak-to-peak current is 20A.

Abstract: Background noise interference is one of the most important factors for low-voltage power line communication’s reliability. By analyzing the background noise of low-voltage power line communication’s channel, the background noise’s measuring circuit is set up and the AR model of the measured background noise is established. Both of them are respectively using singular value decomposition and Levinson-Durbin (LD) recursive method to calculate the AR model’s parameters and a comparative analysis of the simulation is made. The results induct: parameters acquired from the methods of singular value decomposition and LD recursive method are feasible, the parameter model from singular value decomposition is relatively complex, but extremely accurate, which is suitable for the off-line calculation and analysis of the low-voltage power line’s background noise; the parameter model from LD recursive method is very simple, but has a greater loss of accuracy, fitting for online quickly generation of the low-voltage power line’s background noise.

Abstract: This paper is presented a new method for stability analysis and stabilization problems of continuous-time T-S fuzzy systems with time-delay. A fuzzy Lyapunov function is introduced to establish some delay-dependent stability criteria. Less conservative results are obtained by considering the additional useful terms when estimating the upper bound of the derivative of function. Then based on parallel distributed compensation, a delay-dependent stabilization condition is derived and the corresponding controller can be obtained by solving a set of linear matrix inequalities (LMIs).

Abstract: This paper realizes the fault location in overhead line by using wavelet packet decomposition (WPD) and support vector regression (SVR). All various types of faults at different locations and various fault inception angles on a 735kV-360km overhead line power system are used. The system only utilizes voltage signals with single-end measurements. WPD is used to extract distinctive features from 1/2 cycle of post fault signals after noises have been eliminated by low pass filter. A SVR is trained with features obtained from WPD and consequently used in precise location of fault on the transmission line. The simulation results show, fault location on transmission line can be determined rapidly and correctly irrespective of fault impedance.

Abstract: With the increasing demands are beyond the capacity of the power generation and the progressive demands for higher power quality, it requires for further study on distribution system reconfiguration. This paper describes the distribution network reconfiguration algorithms in detail. The advantages and disadvantages of the various algorithms and improvement are also analyzed in this paper. At the end of the paper, the development directions of distribution network reconfiguration are discussed.

Abstract: The gradually extensive penetration of small-scale distributed renewable generators in existing medium-voltage power distribution networks highlights many technical challenges which call for urgent solutions from power utilities. This paper attempts to optimize the power factor of distributed generators (DGs) integrated in distribution networks and presents a novel algorithmic solution. With the aim of minimizing power loss whilst maintaining the node voltage, the problem is formulated with a mathematical model elaborating the DGs and a set of constraints in distribution networks and addressed through adopting an extended particle swarm optimization (PSO) approach. The suggested algorithm is assessed through numerical simulation experiments with the IEEE 33-bus system and the outcome shows that the optimization algorithm can effectively reduce the power loss and promote the node voltages across the overall distribution network.

Abstract: This article discussed the basic principles of the power line carrier application technology and an example scheme, The unique advantage of the power line carrier networking technology is applied in the Internet of things. The advantage of the application of the power line carrier in the difficult environment of radio frequency application and layout is pointed out.

Abstract: Nonlinear loads generate a large amount of characteristic harmonics , deteriorate the power quality of power distribution systems in Advanced manufacturing enterprises. In this paper a novel hybrid active power filter is proposed which consists of a series thyristor switched filter (TSF) and small rated shunt active power filter(APF). TSF is tuned at fifth and seventh order harmonic frequencies. Consequently APF compensates for third and other order harmonics, unbalance current and reactive power. A new control method based on PHC strategy is presented for APF. The device has already got an application in one of the transformer substations of a automobile factory. It’s revealed that the proposed device can improve the power factor , reduce the harmonics injection and enhancement power quality of the power distribution systems.

Abstract: The introduction of distributed generation will bring new challenges to the theory of power electricity market. The problem of loss allocation is one of them. In the paper three contents are introduced. Firstly, a loss allocation method is proposed for power distribution network with distributed generation. Secondly, the changes of loss allocation which introduction of distributed generation before and after brings about are analyzed and compared and relevant conclusions are obtained. Lastly, a typical mini-grid with a distributed generation is simulated. Simulation results prove the correctness and feasibility of the method.