The paper proposes a new control of a transformerless singe-stage single-phase grid-connected inverter in photovoltaic generation systems. The control scheme is mainly based on voltage-oriented control (VOC) with help of second order Generalized Integrator (SOGI). A cascaded control structure with an outer dc link voltage control loop and an inner current control loop is used. The currents are controlled in a synchronous dq reference frame using a decoupled feedback control. The simulated results have proven an excellent performance and verified the validity of proposed system.
In view of the advantage of low voltage power line carrier technique and general packet radio service(GPRS), a solution of fan filter unit(FFU) motor remote mointoring system based on GPRS and low voltage power line communication is introduced. This system combines a framework of low voltage power line communication and GPRS network with host computer monitoring center, which changes the traditional FFU motor control mode, and realize FFU motor remote real-time on-line automatic monitoring.The system implementation methods were described in detail, and the hardware and sofware design were given.The test and practice showed that the proposed has higher efficient and stronger anti-interference capability, which met the requirements of networkization and intelligentization, and a better way for the FFU motor control. The designed system has good application value.
Measurement of bullet data is very important to the target trial. The reliable signal acquisition and analysis is the bases of the design of weapon. When the ordinary photoelectric target work, firelight or ambient light will bring an error trigger signal or cannot capture the shot off target signal. These may affect accuracy and sensitivity of the system. A system of the data acquisition and process based on PCI local bus is introduced in this paper. The device of hardware and data acquisition base on PCI local bus is in detail. Introduce how to design the PCI driver. This system has been successfully used to measure several kinds of projectiles’ velocity.
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