Advanced Materials Research Vols. 986-987

Abstract: To improve the speed sensorless speed control system’s performance, this paper analyzes the rotor flux and speed estimation principle based on MRAS. On this basis, a new online identification method of induction motor stator resistance based on fuzzy logic is proposed. This method takes rotor flux and stator current vector as input and the stator resistance changes as the output. In the simulation environment, we compare the speed waveforms after the increase of stator resistance identification and conduct simulation to the identification effect when doubling the original value of stator resistance suddenly. The experiments show that the method has simple structure, high reliability, low computational complexity and obvious ability to identify the stator resistance changes, and besides, it can significantly improve the speed control system performance.

Abstract: Regards the compound auto transmission as the object of research, an optimal-power ratio optimization algorithm that takes into account the efficiency of CVT was presented in the paper. Firstly, the numerical models of drivetrain were established, which included the engine output torque model and the efficiency model of CVT. Then, the driving power was chosen as the dynamic target, and the optimized objective function was built. According to the requirement of shift gear, the ratio of shuttle transmission components was determined. Based on the Simulation X, the simulation car model with the compound auto transmission was design to confirm the validity and effectiveness of the proposed method.

Abstract: With the development of high-power full-controlled power electronic devices based HVDC voltage source converter (VSC) and pulse width modulation (PWM) technology (VSC-H VDC) technology has become a reality. Currently VSC - HVDC technology in foreign countries in the theoretical study of the transition phase to the experimental system, while the domestic is just beginning, many of the basic theory and applications related to basic issues to be studied. In this paper, based on existing research, analyzes power VSC-HVDC system control strategy proposed dq0 coordinates using a steady state model, and based on the model , designing the control program. Finally, to build a system using SIMULINK simulation model for a steady-state simulation analysis.

Abstract: The micro power generators that depend on converting the ambient energy into usable electrical energy for portable electronic devices have attracted much attention in recent years. A novel microfluidic power generator which is based on reverse electrowetting in a microchannel geometry was presented by Tom Krupenkin and J. Ashley Taylor. This generator overcomes the defects such as low output and low resource utilization of traditional energy converters. Understanding the parameters influencing output of this generator is a key to enhance the power output of it. This paper discussed the effects of factors on generator output by numerical simulation. The results show that promising performance of REWOD-based power generator can be achieved by choosing a thinner dielectric film with high dielectric constant and high break strength, and increasing the droplet oscillation frequency.

Abstract: This paper presents a typical application for a newly developed thermoelectric energy harvesting system. The proposed solar thermoelectric generator (TEG) operates with phase change material (PCM) day and night. An energy management system was connected with the TEG to increase the output voltage while the harvested power was used to drive a wireless transmitter. The wireless receiver controlled the switch of a water tap which functions as a smart cooler of a photovoltaic cell. This study demonstrates a way of using micro-energy to improve macro-energy production smartly.

Abstract: The LCL filter is widely applied as interface between grid-connected inverter and grid due to the preferable high frequency attenuation characteristic. Under the condition of weak grid, impedance value of grid model cannot be ignored, the existence of grid impedance results in different LCL resonant frequencies, which will arise challenges of traditional active damping control. Based on the analysis of band pass filter using active damping control strategy, an adaptive active damping control is proposed in this paper by introducing the application of active notch filter, which can adjust the position of negative resonance point adaptively so as to manage sudden grid changes. Theoretical analysis and simulation results presented on the platform of grid-connected PV inverter system indicate the effectiveness and adaptability of this active damping strategy.

Abstract: Governments have become increasingly concerned about the development of the smart grid, and a series of smart grid demonstration projects have been started. Multi-levels common and integrated infrastructure architecture for smart grid demonstration project was proposed in the paper. The implementation and operation of its back office systems were presented, which include the design, development and deployment of network management system, meter data management system, load control systems, community level and home energy management system, and web portal. The integration between different parts and their managements were also were proposed.

Abstract: To avoid or relief the fatal damage of an earthquake, a seismic automatic alarm system was put forward to meet the needs of power plant. Both a digital accelerometer AKE392B and a programmable automation controller SC200AD-1 were introduced to compose the earthquake emergency alarm system. The AKE392B converts the acceleration of ground motion into a series of digital signal, and this digital signal is transferred to the SC200AD-1 by the field bus EIA485. The PAC in the system is applied to collect the ground motion data, remove the non-seismic interrupts, access an earthquake’s intensity, carry out emergency auto-handling actions by ON/OFF values, and generate emergency alarm to its parent system, power plant management system. Through theory and experiment analysis, the earthquake emergency alarm system could be easily built to measure the ground motion acceleration in accuracy, and generate the seismic emergency alarm rapidly.

Abstract: The battery ability of recovering electricity plays a significant role in improving the regenerative braking performance. In this paper, a control for recovery of braking energy in Electric Vehicles (EVs) with electro hydraulic brake (EHB) is proposed, which makes the recovery transfer to the electric hydraulic pump of EHB directly, rather than being stored statically in the battery. An energy flow strategy was designed for the maximum braking energy recovery based on this control. The simulation results show higher energy recovery rate in comparison to the general recycling control.

Abstract: With the increase of the load capacity and the development of the automation degree, the power dispatching center has a higher requirement for the primary frequency regulation function of the unit aircrew. After a certain period of time when the unit has been put into operation, the primary frequency regulation function must have the conditions to be put into operation, so that the unit can be involved in grid frequency at any time when the conditions are satisfied and the power supply quality can be fully guaranteed ^[1]. The regulation performance of primary frequency regulation plays a vital role in maintaining the stability of the unit aircrew and the power grid, so it is very necessary to conduct the frequency tests for the thermal power units ^[2]. In this paper, we describe the disturbance tests and recovery tests under different load points and different network frequencies. Through the analysis, we can draw the conclusion that the primary frequency regulation function of unit 1 can fully meet the requirement of the frequency regulation of the power grid.