The Importance of Monitoring of Smart Meters
In the more than 100 years history of the electric power industry, "smart meters" is still in the early stages of deployment and use. Because of the electric meter is the front end of the electric power company "register", must be very accurate.
Although there are a large number of requirements for the meters, performance specifications and regulations, and electric power company is trying to ensure the accuracy of meter, but in fact, once certified meter design, manufacture and installation, most of the electric meter accuracy confirmation just only stay in production at the end of the factory test phase. Specific meters in front of the retired live performance can only be estimated by statistical sample test.
In addition, the power is the primary sources of revenue loss power co., LTD. Although usually think the problem is mainly developing economies, but in many developed regions is increasingly serious. Britain, for example, natural gas and electricity markets (Ofgem) office in July 2013, issued a report titled "stop power - diagnosis", which estimates the power theft happened year after year more than 200 million pounds, power companies need to invest another 25 million pounds preventing electricity-stolen, repair or replace equipment been tampered with.
1.The power meter's accuracy is critical
Smart meters relative to electronic and mechanical connectivity is the main advantage of the electric meter. Networking smart meters can remote report of electricity, power management, collecting data and using time to prevent certain types of power. The measuring of electric meter itself is the key, however, is it possible to function to perform more sophisticated diagnosis?
Other industries have the function of the key tasks, such as automotive and industrial, the diagnosis, introducing the concept of "functions", its essence is to check equipment to determine whether the used before use, and then the normal operation. One of such functions of electric power meter industry is the scene during the service life of electric meter accuracy.
Current meter sample test execution site, only rely on site meter internal components remain within the scope of the calibration to estimate accuracy, but this method exists risk. On-site monitoring accuracy is important, because precision affected by the sensor, the sensor is exposed to high current, voltage events and harsh environment. Therefore, diagnosis must include monitoring the electric meter, including sensors and all electronic components.
Electric meter accuracy check usually requires human intervention, disconnect the scene and using special equipment, so need to spend a lot of cost or the implementation of complex apart to complete the on the spot. However, for each meter of noninvasive monitoring technology can change the dilemma.
2. Opportunity for data analysis
Information system architects need to consider the question: "if can get the accuracy of the deployment of each meter on a regular basis, what do you do?" The ability to eliminate failures and defective goods, but better is to collect and analyze the information of electric meter group.
The monitoring accuracy will not violate any laws and regulations, but it can provide management the advantage of the meter. Per hour or a day to collect information, the data quantity is not too big, but the potential is unlimited.
Figure 1 shows the accuracy of high resolution monitor group, which can extract group differences during service life. So can understand manufacturing batch, supplier, deployment, regional differences or different grid topology.
This data can also be combined with other measures, such as season, temperature, humidity, and power consumption, is used to determine whether the need to improve the future electric meter specifications, to provide more repeatable field measurement.
In addition, knowledge of the performance of the whole group, a goal can be set for the sample test, meet the requirements of regulatory agencies. Implementation of the large data analysis of the electric meter group can make the responsibility of the power companies to better deal with risk.
Three solutions
So far, did not exist, including the meters, on-site operation and self-check accuracy test. It wouldn't change, therefore, to identify and report equipment precision mechanism. The blank highlighted the demand of the new monitoring technology, namely the continuous monitoring site meter accuracy, provide built-in, since the test function, used to check the performance of the electric meter during the whole life. The technology must be in meters run-time monitoring meter accuracy, shall not affect the measurement function at the same time.
To cope with the challenges, ADI company developed mSure technology (as shown in figure 2 green box), aims to inject known reference signal sensor continuous monitor the response of the electric meter. After stacking, sensors can detect at the same time reference signal and load signal. The combined signal from the same path, so existing combination signals at the end of the electronic device digital form.
Detection circuit is the only reference signal from the load signal extraction, once completed this step, the system will have from the sensor to the meter digital representation of transfer function.
The same transfer function can be applied to the load signal to digital, said the change in order to determine the accuracy of power companies. To keep energy data, monitoring signals digitally removed from the signal path, only energy into the measurement data transmission system.
Because has the ability of monitoring sensors and electronic devices, this technology can also be used to detect many existing "tamper-proof" meter cannot identify power method. Even if power company stopped only a few tamper with the event, can significantly improve profitability.
4.Summary
Current meters certified before supply and installation, calibration and factory testing, to ensure a complete set of precision and performance standards, and meet the different level of different areas. Later, electric meter can maintain accuracy can only rely on trust (components quality and statistical test).
By adopting strict meter monitoring method, power companies can use internal connectivity smart meters provide a test precision of the non-invasive, application of big data analysis in order to better understand the precision of electric meter deployment, reduce the power meter.