Application of Hollysys G3 Small PLC in Beijing su

Hollysys G3 Small PLC in Beijing subway distribution transformer remote monitoring system

1 preface

with the rapid development of China's economy, the power consumption is increasing, and the safety and reliability of distribution is becoming increasingly important. The distribution network is composed of distribution transformer, distribution cabinet and distribution line. The safety and reliability of distribution transformer determines the distribution of power, which will become a perfect choice to control the distribution of gas and liquid flow, and the safe and reliable operation. Due to the scattered distribution and large interference of distribution transformers, it is difficult to communicate between distribution transformers, and it is difficult to realize the centralized monitoring of a large number of distribution transformer parameters with conventional automatic monitoring means. When the distribution transformer fails or is damaged by human beings, such as overload operation, it cannot be reported to the monitoring center in time, which is easy to cause huge losses. The intelligent remote monitoring system of distribution transformer described in this paper provides a set of feasible schemes to solve the above problems

2 system functions

1 Protection and monitoring functions: transformer current differential protection, transformer differential current breaking protection, transformer overcurrent backup protection, overvoltage protection, current measurement, voltage measurement, temperature measurement, power factor measurement, harmonic measurement

2. Abnormal alarm function: in case of alarm events (open circuit, short circuit, overload, overheating, undervoltage, power failure, etc.), the corresponding processing shall be carried out locally, and the alarm information shall be sent to the central management computer equipped with DP master station card through DP module. After receiving the alarm information, the central management computer will actively pop up a warning window, tell the user which monitoring point has the alarm type and solutions, and provide alarm data

3. Self protection function: the system has self detection and data power failure protection functions

3 scheme design

HOLLIAS LEC G3 small integrated PLC of hollys has good expansion performance, high cost performance, good anti-interference and rich instructions. The scheme adopts the Llias LEC G3 series PLC for data acquisition and processing from ho to April 2016, as shown in figure 1:

Figure 1 intelligent remote monitoring system of distribution transformer

each DP slave station of the intelligent remote monitoring system of distribution transformer measures the local distribution transformer in real time, including the overload of current and voltage, and detects the operating parameters of the equipment, mainly including the working state of temperature and pressure. Then the data is transmitted to the central management computer in the monitoring room through the DP slave communication module to complete the monitoring function of the whole system. DP slave station includes a CPU module lm3107, a 4-channel analog quantity acquisition module lm3310, a 16 channel switch quantity input module lm3212, an 8-channel switch quantity output module lm3222 and a DP slave station communication module lm3401

each DP slave realizes communication with DP master through PROFIBUS DP bus. For the relevant data of the working state of the distribution transformer, the analog quantity is collected by lm3310, and the switching value is directly obtained by lm3107 and lm3212. The collected data is processed in the CPU module lm3107, and various protective measures are made. The switching value is output by lm3222, and then lm3107 transmits the analog quantity and switching value to be transmitted to the DP master station in real time through the DP communication module lm3401

4 solution advantages

the solution proposed in this paper has the following advantages:

1 Using HOLLIAS LEC G3 PLC to detect the relevant data of the working state of the distribution transformer has the advantages of strong anti-interference and convenient maintenance

2. HOLLIAS LEC G3 PLC has strong communication ability, which guarantees the real-time performance of data transmission. The central management computer summarizes the relevant data of each distribution transformer through PROFIBUS DP bus, and constantly refreshes the real-time database

3. When the distribution transformer fails, the central monitoring room can find the fault at the first time, provide the fault follow-up analysis report, point out the cause of the fault, and put forward fault handling opinions

5 conclusion

this scheme has been successfully applied to the distribution system of Beijing metro lines 1 and 2, and the operation effect is good. The dispatcher can remotely monitor all the distribution transformers in the distribution and monitor the real-time state parameters of the distribution transformers. The system not only improves the efficiency of the staff, but also plays an important role in improving the safety and reliability of the whole power distribution. HOLLIAS LEC G3 PLC has good anti-interference and powerful communication functions to ensure the safety of power distribution, which greatly improves the automation level of power distribution and enhances the safety and reliability of power distribution and subway operation