Design of an automated meter reading system using NI development systems and AMR systems

We need AMR systems that can collect data from meter devices at remote substations to provide real-time data for long-term data management and daily power usage analysis. In addition, the system must be able to provide automated report generation, energy statistics, and graphical presentation of the power grid in a geographic information system (GIS). In addition, we need systems that can help power companies provide more services.

Our applications address the following key challenges in traditional instrumentation systems:

1. Dependence on people

2. A lot of operation time

3. Human Error

4. Restrictions on the use of instrumentation equipment in rural substations

5. The collected data is not accurate enough to be used for reliability analysis

6. Failure notification is not possible

We developed a flexible substation AMR system using the NI cRIO-9014 embedded real-time controller and GPRS communication interface to collect data from remote substation instrumentation using the NI LabVIEW Real-Time Module. The CompactRIO system provides a good solution for processing data, managing multiple tasks, and communicating using the TCP/IP network protocol.

AMR systems are used to measure electrical parameters from instrumentation installed at remote substations. We built a GIS-based application that provides a graphical view of the substations in a centralized data center. The software provides the ability to update GIS real-time parameters from remote substations.

The software system is divided into five modules:

1. Collect data from substation instrumentation

2. Communicate between the Data Center and the CompactRIO Controller

3. GIS module

4. Substation single channel display/network principle model module

5. Reporting and Analysis

Figure 1. AMR system architecture

Collect data from substation instrumentation

The digital I/O module can be used to monitor the circuit breaker status and send SMS and email to the responsible substation when the circuit breaker status changes. The module reads the following parameters from the instrument equipment:

* Electrical

* temperature check

* Maximum demand

* Fault detection

Communication between the data center and CompactRIO

NI's GPRS module serves as the communication medium, allowing communication between the remote substation and the data center. Data collected from the AMR interface is transmitted using TCP/IP via the GPRS modem and written to the SQL server database in the data center using the LabVIEW Database Connectivity Toolkit. We built a custom website using the LabVIEW Web Publishing Tool to provide access to real-time and historical data. The system is able to log data in the memory of the CompactRIO controller when communication fails, and it can read the data when communication is restored.

GIS

GIS is used to display the location of energy system resources. The idea of ​​integrating GIS and AMR is to provide a graphical user interface for the AMR system so that the power grid can be visualized, as shown in Figures 2 and 3.

The GIS contains special symbols that are dynamically updated using AMR data, continuously representing the current state of the grid. The operator can view the target location on the map and zoom in and out. The map automatically switches between levels at a predetermined zoom ratio, displaying a map that the operator is familiar with in a window.

Figure 2. GIS and substation

Figure 3. GIS zoom out

Substation single line display

The single-line display (SLD) is used to symbolize the substation, substation bus configuration, transformers, and circuit breakers. The AMR system updates the instrument parameters from the remote substation on the SLD, such as each phase current, voltage, power, and power status of the circuit breaker (Figure 4). Detailed parameters can be viewed in another window (Figure 5). The displayed data comes from the database and is updated by the AMR system.

Figure 4. Substation single-line display

Figure 5. Substation real-time parameters

Network principle model

This application includes the functionality to draw and document the physical grid model (substations, HT taps, transformers, and LT taps) and can be updated based on changes (Figure 6). This application is an extension of the AMR system that can graphically display the distributed network and configure network elements at the substation level. Data is collected from the distributed transformers and the instrumentation data is stored in CSV format using a handheld device. The collected data is stored in a database for reporting and analysis.

Figure 6. Power grid model

Reporting and Analysis

Data collected from remote instrumentation devices provides the following information and reports:

* Instruments that have been tampered with or are reading zero

* Energy consumption/supply level, energy consumption of network equipment (LT connectors, transformers, HT connectors and substations) over a period of time

* Maximum requirements, voltage, current, power consumption/load per connector

* Operational status reports including peak demand vs. base demand, line and transformer/substation loading, power factor, reactive power demand, diversity factor and voltage conditions

* Reliability report including the duration of supply disruptions

* Graphical reports including load, voltage waveform, load duration and power factor curves

* Maximum demand for LT/HT joints, transformers and substations

* Abnormal consumption report

* Customized reports such as energy balance, high consumption areas, consumption trends and load/voltage curves

Figure 7. Graphical report

Figure 8. Energy Account Report

in conclusion

The AMR system we developed using NI hardware and software is a reliable and consistent solution for power utilities. We were able to integrate instrumentation, condition monitoring, GPRS communications, and application software such as GIS, data acquisition, SLD, and report generation using a single platform. As a result, we avoided integration issues and reduced development time. The system helps power utilities improve the state of the grid and meet future challenges in India's power sector.

At the time of this article’s publication, the system has completed substation testing and we are developing applications to read meters from multiple substations in a distributed network across geographical areas, as well as adding more advanced features to the application.