Design of power supply monitoring system based on fieldbus technology

The hardware of the system uses PROFIBUS fieldbus and Kinco-R1 remote I/O series modules. Two Kinco-B131 PC adapter cards are used to connect the microcomputer to PROFIBUS; two Kinco-R131-08IV A/D converters with a total of 16 points collect analog signals in the field and convert them into digital quantities and transmit them to the microcomputer through the bus; eight Kinco-R121-08DX 8-channel DI digital input modules with a total of 64 points and 37 15-channel DI digital input modules with a total of 555 points complete the monitoring of the system switch quantity; two Kinco-B141 repeaters extend the bus distance; 14 intelligent AC sampling modules with a total of 196 points, a total of 831 points in total.

The system software is configured using the "Kingview" software, which runs on the Microsoft Windows 95/98/NT Chinese platform with a full Chinese interface. It uses new technologies such as multi-line and COM components to achieve real-time multi-tasking, and the software runs stably and reliably.

2. System structure

(1) The system structure is shown in the figure below: The two master stations are composed of two industrial computer systems, which are installed in the central station and the south station building respectively. They read the slave station data and display it on their respective CRTs.

Kinco-R1 series I/O modules act as slave stations on the PROFIBUS fieldbus to collect field data and perform necessary control.

The master station and slave stations together constitute a multi-master and multi-slave PROFIBUS system. The master station exchanges information with the slave stations scattered in the basement, east annex building, west annex building, and south station building of the central station within a predetermined period. Any master station can read the information of the slave station, so it is a redundant structure.

(2) Basic configuration of system hardware

A. Two hosts, using high-end PC-compatible Pentium II microcomputers, with a main frequency of 233MHZ, 64M memory, a hard disk of *G, two PC adapter cards, and running in dual-machine hot standby mode.

B. Printer: One EPSON LQ1600K Chinese and English printer.

C. Monitor: High-resolution color display SVGA card driver with a resolution of 1024*768, diagonal size 21 inches.

D. Sampling module: Two Orient-2010 A/D converters are used to collect analog signals such as temperature and humidity.

E. AC sampling module: Kinco-R1 series power transmitter is used to sample three-phase voltage and three-phase current to complete the patrol measurement of U, I, P, Q, power factor, switch status of each substation, continuous accumulation of active and reactive power, event recording, signal alarm and other tasks.

F. Switching quantity module: Use Kinco-R1 series 8-channel digital input module and Kinco-R1 series 15-channel digital input module to realize the collection of all switching quantities on site.

G.UPS uninterruptible power supply provides reliable power supply guarantee to prevent sudden breakpoints from causing paralysis of the monitoring system and production losses.

3. Basic functions of the system

(1) Functions of the power supply center operation station

The power supply center operation station is the monitoring center of the entire low-voltage power supply system. It monitors the switch status, temperature, humidity, illegal intrusion alarm, real-time curves, historical curves, system reports and other detailed conditions of the systems in each distribution room of the central station, south station building, east annex building and west annex building.

(2) Field Instruments

The field instrument provides a standard 4-20 mA industrial current signal, which is digitally converted by the Kinco-R1 remote I/O series module and then sent to the host computer via the PROFIBUS fieldbus for monitoring.

(3) Fieldbus technology

The use of PROFIBUS fieldbus technology is a significant feature of the entire system. PROFIBUS fieldbus has simple hardware composition, practical network protocol, and strong anti-interference ability. It is internationally recognized as one of the best fieldbuses.

4. Functions implemented by the system

(1) Automatically monitor the switch status of the low-voltage power distribution system and the real-time electrical values ​​of voltage, current, power, power factor, electric energy, etc.;

(2) Fault alarm, real-time tracking display, and automatic pop-up of the fault location screen;

(3) Electricity billing;

(4) Transformer over-temperature alarm detection and monitoring;

(5) Indoor temperature and humidity detection and display in the power distribution rooms of the east and west annex buildings;

(6) The east and west annexes are unattended, fire-proof, theft-proof, and anti-illegal intrusion-proof;

(7) A master station is set up in the central station and the south station building to form a redundant system;

(8) CRT screen monitoring step by step;

(9) The master station and the slave station communicate using PROFIBUS fieldbus;

(10) An upgrade and expansion interface is provided.