Deduced the relationship between the power factor (PF) and the angular fre-quency according to the simplified equivalent circuit of asynchronous motor, forming a power factor auto-control system. An anti-interference ...Deduced the relationship between the power factor (PF) and the angular fre-quency according to the simplified equivalent circuit of asynchronous motor, forming a power factor auto-control system. An anti-interference circuit was also introduced in the middle voltage link of inverter to avoid the shift of the optimum PF point caused by the change of the load and the reliable run of the control system was assured. The experi-ment results show that it has a good self-adaptation in the whole scope of speed ad-justment and an obvious economization on energy while it runs under load.展开更多
In recent years the variety and complexity of Wireless Sensor Network （WSN） applications, the nodes and the functions they are expected to perform have increased immensely. This poses the question of reducing the ti...In recent years the variety and complexity of Wireless Sensor Network （WSN） applications, the nodes and the functions they are expected to perform have increased immensely. This poses the question of reducing the time from initial design of WSN applications to their implementation as a major research topic. RF communication programs for WSN nodes are generally written on microcontroller units （MCUs） for universal asynchronous receiver/transmitter （UART） data communication, however nowadays radio frequency （RF） designs based on field-programmable gate array （FPGA） have emerged as a very powerful alternative, due to their parallel data processing ability and software reconfigurability. In this paper, the authors present a prototype of a flexible multi-node transceiver and monitoring system. The prototype is designed for time-critical applications and can be also reconfigured for other applications like event tracking. The processing power of FPGA is combined with a simple communication protocol. The system consists of three major parts： wireless nodes, the FPGA and display used for visualization of data processing. The transmission protocol is based on preamble and synchronous data transmission, where the receiver adjusts the receiving baud rate in the range from min. 300 to max. 2400 bps. The most important contribution of this work is using the virtual PicoBlaze Soft-Core Processor for controlling the data transmission through the RF modules. The proposed system has been evaluated based on logic utilization, in terms of the number of slice flip flops, the number of 4 input LUTs （Look-Up Tables） and the number of bonded lOBs （Input Output Blocks）. The results for capacity usage are very promising as compared to other similar research.展开更多
基金Supported by Liaoning Educational Foundation(202183386)
文摘Deduced the relationship between the power factor (PF) and the angular fre-quency according to the simplified equivalent circuit of asynchronous motor, forming a power factor auto-control system. An anti-interference circuit was also introduced in the middle voltage link of inverter to avoid the shift of the optimum PF point caused by the change of the load and the reliable run of the control system was assured. The experi-ment results show that it has a good self-adaptation in the whole scope of speed ad-justment and an obvious economization on energy while it runs under load.
文摘In recent years the variety and complexity of Wireless Sensor Network （WSN） applications, the nodes and the functions they are expected to perform have increased immensely. This poses the question of reducing the time from initial design of WSN applications to their implementation as a major research topic. RF communication programs for WSN nodes are generally written on microcontroller units （MCUs） for universal asynchronous receiver/transmitter （UART） data communication, however nowadays radio frequency （RF） designs based on field-programmable gate array （FPGA） have emerged as a very powerful alternative, due to their parallel data processing ability and software reconfigurability. In this paper, the authors present a prototype of a flexible multi-node transceiver and monitoring system. The prototype is designed for time-critical applications and can be also reconfigured for other applications like event tracking. The processing power of FPGA is combined with a simple communication protocol. The system consists of three major parts： wireless nodes, the FPGA and display used for visualization of data processing. The transmission protocol is based on preamble and synchronous data transmission, where the receiver adjusts the receiving baud rate in the range from min. 300 to max. 2400 bps. The most important contribution of this work is using the virtual PicoBlaze Soft-Core Processor for controlling the data transmission through the RF modules. The proposed system has been evaluated based on logic utilization, in terms of the number of slice flip flops, the number of 4 input LUTs （Look-Up Tables） and the number of bonded lOBs （Input Output Blocks）. The results for capacity usage are very promising as compared to other similar research.
