Advanced Materials Research Vol. 676

Abstract: Abstract. It is introduced that the complementary advantages between Zigbee and PLC underground in Electrical Control Engineering, improving effectively the reliability and stability of transmission of PLC. Not only is the principle diagram of the design given, also a design of OFDM modulation and demodulation from the signal of Zigbee is realized based on FPGA. The program and simulation is designed for OFDM modulation and demodulation with ISE10.1. It is improved feasible with the data of experiences.

Abstract: The performance of Diesel engine control system influence the engine combination property directly. The traditional mechanical control system can't meet the requirements of the fuel consumption and emissions. We should turn to the advanced electronic control system. This article introduced the basic frame and control mode of low-speed common rail diesel engine electronic control system, and according to the control object, the whole control system is divided into different modules to detailed analysis.

Abstract: In order to study the power distribution strategy of AC and VSC-HVDC hybrid system for wind power integration, a strategy based on improving the transmission capacity of AC lines and reducing the power loss is proposed. By use of the decouple control of active and reactive power of the VSC-HVDC, the transmission capacity of the AC lines can be improved by absorbing enough reactive power, AC lines have the priority before they have reached their transmission limit, meanwhile the VSC-HVDC acts as STATCOM. When the AC lines have been fully used, the VSC-HVDC will act as STATCOM as well as transmit the rest power. A DFIG wind power integration system is set up by use of PSCAD/EMTDC, the simulation results show that the power distribution strategy can realize the wind power integration successfully and reduce the power loss, it can regard as a good method for wind power integration.

Abstract: In the electricity draws control system, the change of Low-velocity area of Rs will bring about a series of problem, especially the stator current and flux, will cause the distortion of the speed pulse vibration. The test discussed control scheme and optimization designs of asynchronous draw motors from exchange transmission electric locomotive operation characteristic demand. It adopts control strategy of neural network direct torque control (DTC) to control electricity draw the locomotive, to analyze the reacting of starting and sudden change of load, verifying this method may effectively improve the dynamic performance of the asynchronous motor, got up the very good inhibitory action to the low speed area torque pulsation. Thus the simulation results have proven the neural network DTC control strategy feasibility.

Abstract: The paper presents a design scheme of a BLDC motor control system based on dual MCUs communication for electrical and electronic application, discusses the rotor position detection circuit, drive circuit, protection circuit, velocity measurement circuit, and dual MCU control circuit, and gives the hardware circuit and the block diagram of software program. It is proved that the design is practical and reliable.

Abstract: A fault phase selection method is proposed based on arc voltage after analysis of inadequate of fault phase selector existed in the paper. A precise fault phase selection can be achieved by using arc voltages in conjunction with phase current differences and sequence components of currents. The method proposed can solve false tripping problems in transmission line protections when single phase to ground faults occur with great reliabilities. Simulation results show that the method can identify faulted phase or phases correctly and effectively.

Abstract: To achieve safety commutation of the bidirectional switch in Matrix Sinusoidal waveform converter with high-frequency link, a decoupling time-driven strategy is proposed in this paper. The two gates in each bidirectional switch are driven by different signals, so the voltage surge caused by non-synchronous commutation of two bidirectional switches can be avoided, and both ZVS and ZCS are also achieved. Since the current polarity of load need not to be detected, the circuit is easy in realization. Experiments has been carried out to verify the feasibility of the proposed method.

Abstract: In this paper, a new topology of compensated AC regulated power supply (ACRPS) in electric power systems based on a high-frequency isolated transformer (HFIT) is proposed. In order to overcome the slow response and low accuracy of the existing ACRPS, the phase shift regulating control (PSRC) based on instantaneous value of voltage single closed loop is applied as well as the software phase locked loop (SPLL). The proposed ACRPS has been simulated in the case of the voltage fluctuation, harmonics and frequency shift with Matlab. The simulation results show that output voltage precision is controlled within 0.5% and total harmonic distribution (THD) can be limited to less than 1%. In a word, the feasibility of the proposed ACRPS is effectively verified.

Abstract: Serving as an important thermal segregation material for air and space vehicles, zirconium diboride has to suffer ultra-high-temperature that might be over 2700°C. However, the highest working temperature we can achieve for the testing of the mechanical properties of such kind of materials is less than 1500 °C. Moreover, the high temperature furnaces are low-usage, and have along experimental period. Making use of the satisfactory electrical and thermal conductivities, we could heat a Zirconium diboride specimen with electrical current. The electrical heating of a Zirconium diboride specimen is simulated with the commercial available finite element code ABAQUS. The temperature and cooling of copper electrodes and that of collets, is also analyzed, and the temperature distributions are obtained. In order to achieve reasonable distribution of temperature in the specimen, the copper electrodes and the collets, the corresponding cooling facilities is designed, and the cooling liquids are selected.

Abstract: The equivalent consumption minimization strategy (ECMS) is a method to reduce the global minimization problem to an instantaneous minimization problem to be solved at each instant. The adaptive ECMS is a development of ECMS in which the equivalence factors are not pre-coded, but rather calculated online. The equivalence factors, their optimal value, which minimizes the cost function while maintaining the vehicle substantially charge sustaining, depends on the specific driving cycle. The method proposed in this paper is one of the most important simplifications for actual real time implementation of A-ECMS and power delivering in energy management for HEV. The charging factor can be calculated if the discharging factor is calculated in the experiment for real time. And only a subset of (charging and discharging factors) generates a trend close to zero which indicates charge-sustainability.