Keywords: AMC series intelligent monitoring unit, simplify the system, reduce investment, high cost performance
0 Introduction With the development of the power distribution system, the direction of the development of integrated and networked various instruments in the intelligent distribution circuit is becoming more and more clear. At present, the advantages of single-loop integration have appeared, but the integration of multiple loops has not yet occurred.
This article will introduce the application of the newly developed AMC series multi-loop intelligent monitoring unit in the intelligent distribution outlet circuit. This series of monitoring units is mainly used for the monitoring of electrical parameters of multiple distribution outlet circuits. It centrally measures, displays, and integrates the bus voltage in the circuit, the current, power, energy, and switching status of each circuit. Communication output realizes the centralized measurement and monitoring of distribution outlet circuits with simpler monitoring requirements. An AMC multi-circuit monitoring unit can realize the monitoring functions of the above multiple circuits, which greatly facilitates system wiring, installation and debugging; In order to reduce the user's investment and reduce the cost of the system, it will surely lead the development direction of the smart distribution field at home and abroad, and become the mainstream of the development of the outlet loop monitoring system in smart power distribution.
1 Technical background In the traditional intelligent distribution outlet circuit, to achieve comprehensive monitoring of various electrical parameters of each load in the circuit, there are generally the following two networking methods (taking three-phase as an example):
Option 1: (Figure 1)
figure 1
This scheme is a relatively common scheme in the three-phase intelligent distribution outlet circuit. In the monitoring of the load of the distribution outlet circuit, users generally need to monitor various electrical parameters of each load, including the current, voltage, power, energy, and switching status of each load. Therefore, in the design scheme, for each electrical parameter, the user needs to configure a meter that can measure various electrical parameters separately. As can be seen from Figure 1, in order to monitor each load, the user must configure an ammeter, 1 for each load A voltmeter, a power meter, an energy meter, an I / O module. And in order to achieve network management, each instrument must also be able to communicate. It can be seen from Figure 1 that there are five electrical measuring instruments used to monitor each three-phase load. The disadvantage of using this scheme is that multiple meters are required to monitor various electrical parameters of each load. The more monitoring channels, the more meters are used, and it is inconvenient for users to install, maintain, and manage. And the investment is large. The advantage is that the failure of a single instrument does not affect the monitoring of other electrical parameters of the distribution circuit, the measurement accuracy is higher, and the real-time performance is stronger.
Option 2: (Figure 2)
figure 2
This scheme is also a relatively common scheme in the three-phase intelligent distribution outlet circuit. This program is more advanced than the above program in that the instrument used to monitor the electrical parameters of each loop is replaced by a multi-function smart instrument, and a multi-function instrument integrates measuring current, voltage, power, energy and The switch input and output are integrated, and network communication can be carried out. The advantage of this scheme is that only one meter can be configured for each load to realize the measurement and control of all electrical parameters of the load. The network is convenient, the user investment is less than scheme 1, and the installation, maintenance and management are more convenient. The accuracy is higher and the real-time performance is stronger. The disadvantage is that once the meter is out of line, the load cannot be continuously monitored.
The above two schemes are commonly used in the intelligent distribution outlet circuit, but the shortcomings of the above two schemes are obvious, and the large investment cost is a major disadvantage. Moreover, it is inconvenient for wiring, installation and debugging.
2 AMC series intelligent monitoring unit technical indicators
AMC series intelligent monitoring unit is a multi-loop intelligent power distribution monitoring device developed after full investigation and combining with actual needs in response to the monitoring requirements of the general circuit in the outlet circuit. The monitoring unit is divided into two series of single-phase and three-phase, and its model classification is shown in Table 1. Its technical indicators are shown in Table 2. The appearance and installation dimensions are shown in Figure 3, generally installed in the power distribution cabinet.
Table 1 Product model and function
Table 2 Technical indicators
image 3
3 Introduction to the design of AMC series intelligent monitoring unit
The principle design of the AMC series multi-loop intelligent monitoring unit uses multiple electronic switches + 1 energy measurement chip + 1 CPU to realize monitoring of multiple loops. The principle block diagram is shown in Figure 4.
Figure 4
The core device CPU selects Freescale's MC9S08AW32 single-chip microcomputer. It is the first device based on the highly energy-efficient S08 core. It has abundant on-chip resources and outstanding anti-interference capabilities. Contains 32K bytes of user program space, on-chip integrated 2048 bytes of RAM, supports BDM on-chip debugging function, on-chip integrated watchdog circuit.
The energy measurement chip uses ADI's high-precision three-phase energy measurement chip ADE7758, which is suitable for measuring active power, complex power and apparent power in various three-phase circuits (regardless of three-wire system or four-wire system). The IC is embedded with a high-precision analog-to-digital converter and a fixed mode digital processing signal processor (DSP). It has digital integration, digital filtering, and many practical energy monitoring and measurement functions. It is a new generation of high-performance all-digital energy meters Ideal chip.
The electronic switch adopts the CD4052 high-speed electronic switch with a choice of double four. Under the control of the single chip microcomputer, high-speed switching between different current signals is realized.
The multi-channel current signal enters the power chip through the electronic switch, and various electrical parameters of multiple circuits can be measured by the power chip in combination with the bus voltage.
4 Application of AMC series intelligent monitoring unit
4.1 Typical Application Figure 5 is a typical application diagram of the AMC series three-phase multi-loop intelligent monitoring unit. In the application, all electrical parameters of the three three-phase loads in the outgoing circuit are measured by one AMC three-phase multi-loop monitoring unit. And with Modbus communication output for users to remotely monitor and control.
Figure 5
Figure 6 is a typical application diagram of AMC series single-phase multi-loop intelligent monitoring unit. In the application, all electrical parameters of 9 single-phase loads in the outgoing loop are measured by one AMC single-phase multi-loop monitoring unit. And with Modbus communication output for users to remotely monitor and control.
Image 6
4.2 Application Cases Figure 7 is a 0.4kV low-voltage distribution outlet diagram of a radio and television building in Jiangsu. In this design drawing, the current measurement of each single-phase load is implemented using a CL72-AI (measurement of single-phase current) meter, and the current measurement of each three-phase load is implemented by CL72-AI3 (measurement of three-phase current). It can be seen from the figure that a total of 12 instruments are used in this outlet circuit.
Picture 7
Fig. 8 is the modification made to the system of Fig. 7 after adopting the AMC multi-loop monitoring unit. As can be seen from Figure 8, 1 AMC16-1E9 replaces 9 CL72-AI, 1 AMC16-3E3 replaces 3 CL72-AI3, greatly simplifies the system, and can simultaneously detect the bus voltage, each outlet circuit Electric energy, and can use the communication interface to realize the internal electric energy measurement, assessment and management of the radio and television building.
Picture 8
5 Conclusion
AMC series products are powerful, and a single meter can measure multiple electrical parameters of multiple loop loads. Comparing the two design schemes of Figure 7 and Figure 8, using the AMC series multi-loop intelligent monitoring unit can greatly simplify the system design scheme. Compared with the traditional scheme, it reduces the user's investment cost and facilitates the system's wiring, installation, debugging, Maintenance and other advantages.
The article comes from: "Building Electricity" No. 5 of 2007.
references
[1] Shanghai Ankerui Electric Co., Ltd., AMC series multi-loop monitoring unit selection manual, 2006.
About the Author:
Yu Jing, female, undergraduate, engineer of Wuhan Ankerui Electric Co., Ltd., the main research direction is intelligent power monitoring and power management system
Pm Stepper Motor,Square Flange Stepper Motor,High Precision Stepper Motor,Permanent Magnet Stepper Motor
Changzhou Sherry International Trading Co., Ltd. , https://www.sherry-motor.com