Throw-in Device And Power Quality Parameters Monitoring System Based On GPRS

Most of the traditional dual power supply for automatic switch device is composed of relay, contactor, and the corresponding hardware connection, according to different operation requirements for automatic switch circuit, but cheaper device volume, switch slow, contact, easily damaged greatly affect the continuity and stability of the power supply; Due to their function, the shortcomings of poor flexibility, less current power system scale is getting bigger, the structure becomes more complex, the performance requirements also more and more high, the traditional automatic switch device is not very practical.This paper in the light of the shortcomings of the traditional case since the switch device is studied and designed by S7-200PLC control of full automatic switch system, choose to have the Modbus communication protocol of intelligent electric energy meter and intelligent circuit breaker, used to measure the electrical parameters of power supply and control for standby power, and by profibus-dp network real-time data exchange to local monitor. The use of fieldbus hardware connection, instead of the traditional point-to-point communication is stable and reliable, to safeguard the quality of power supply at the same time improve the automation level of power supply system. Design, in order to solve the enterprise office center over a long distance to the operation of the power supply system, power distribution parameters is difficult to monitor problem, creative USES the GPRS wireless communication mode, the system of real-time data transmission to the monitoring center, and displayed in the WinCC monitoring menu, staff through simple operation in the monitor screen equipment remote control of the scene.This design mainly from the following detailed study:(1) Double power supply for automatic switch system design. Mainly includes for the pitch control system of power supply and working mode and working style. Which works in the control rule is prepared from the cast device for must follow the principle of was the key to system software and hardware design. Prepare the switch device works with bright and dark is installed spare two kinds, in this design for the switch device work normally in standby mode. In the system software design with dark and backup control program is installed at the same time, only a modest changes in the external hardware connection, you can change the way prepare the cast work, improve the portability of the equipment.(2) The network structure and network configuration of the system. This monitoring system is mainly composed of the remote monitoring stations, GPRS wireless communication network, the local monitor, the scene of equipment and terminal station. System according to the function of each component is different, different hardware and software configuration.(3) The system hardware and software implementation. Pithead heap-leaching in order to save the design cost, at the end of each two transformer secondary side of transformer substation are installed by the detection circuit of voltage transformer and the voltage relay, voltage state of two way power detection, collected through the native integrated I/O port of PLC. Three intelligent circuit breaker through Modbus network upload it, brake state signals to PLC; Installed on the two low voltage bus intelligent electric energy meter respectively through the Modbus network upload their distribution parameters on the bus to PLC, including voltage, current, active power, reactive power and power factor. S7-200PLC through these data to determine power supply is normal or not, and then through the Modbus network signal control of intelligent circuit breaker on-off. PLC by EM277through profibus-dp network, real-time data exchange to local monitor and displayed in the local PC WinCC monitor screen. At the same time, through wireless communication module of PLC MD720-3pass the data to GPRS public network, and then displayed on the remote monitoring PC WinCC.This monitoring system by S7-200PLC as the controller, the power supply system can work in dark standby mode can also work in standby mode, the local monitor and monitoring and remote monitor, monitor each pithead power supply substation real-time distribution parameters, the circuit breaker working status, fault alarm record, etc., and choose to manually, since the vote from the complex or couldn’t since the compound mode. It guarantees the continuity and stability of the power supply of an effective monitoring system for the enterprise.