Businesses are faced with multiple challenges relating to power distribution including unpredictable power quality, unplanned outages, and unstable energy prices. As growth in new technologies and data consumption continues to rise, businesses can no longer afford to have blind spots in their low voltage power infrastructure.
Although LV switchgear assemblies are often a small part of a larger power system, they still present a significant risk of arc flash and fire. Therefore, it is important that LV switchgear efficiency and reliability is on par with the rest of the system to avoid costly failures that impact upstream equipment. The first step to managing LV power distribution efficiently is understanding how the system operates; this can be achieved by integrating a range of metering and monitoring solutions. Energy management systems (EMS) can be used to monitor, control and optimise power distribution. An EMS tracks power usage and changes within the network, alerting facility managers to potential problems before they arise. This helps to maximise the availability and reliability of critical processes while optimising energy usage and operational efficiency. Every EMS system consists of following 3 levels
1. Field Level
At this level of the system metering devices including sensors, PLC’s and RTU’s are employed to record and process performance data from their respective switchgear components, the data recorded will depend on the capabilities of the metering device employed. Devices can be placed at a variety of points within an electrical system, the priority of where they are placed will be determined by the data required. The level of insight available into the electrical system will depend on the type and placement of the metering devices.
With extensive metering options available, complexity can range from a simple voltage measurement to measuring individual power usage to accurately bill data centre tenants. Varying metering frequencies can also be employed depending on the nature of the data being recorded. For instance, temporary metering can be integrated into an LV switchgear system to monitor less critical switchgear functions at regular intervals. Whereas permanent metering would be required to record primary functions such as circuit breaker performance which must be continually monitored to ensure safe and reliable system operation.
Generally, the greater the complexity of the metering device, the greater the cost. Therefore, it is vital that metering requirements for each point in the system are carefully assessed to avoid overdesigning the system. For instance, whilst complex metering will provide detailed data with more accuracy, it may not be needed to record simple energy measurements. Typically, a power monitoring system will have 2 or more discrete metering points that are both connected to a communication medium.
2. Automation Level
For devices within a network to successfully communicate, all connected devices must understand the signals they are receiving in order to interpret them accurately and carry out tasks as expected. Communication protocols set out a common rule structure that EMS systems can use to automate the transmission of data collected by the metering devices to the human machine interface. The protocols used will differ for each EMS; ethernet, Modbus, internet and LonWorks are all examples of the platforms used.
The automation level is essentially the glue that holds the energy management system together as it converts the raw metering data into meaningful information.
3. Management Level
At the management level, a software application is required to translate the metering data transmitted by the communication protocol into a user-friendly format. This software, referred to as an HMI (human machine interface) allows the end user to use graphical representation to evaluate and control energy usage remotely. Most of the time, only the HMI will be visible and interacted with by the end user, therefore it is important that the software employed presents the required data in a clear and concise manner.
Reasons to invest in an LV energy monitoring system
- Safety
Since most low-voltage switchgear assemblies are custom-built with no uniform safety specification, stricter monitoring protocols may be required in order to maintain a safe and reliable service. Energy monitoring systems also facilitate predictive maintenance, as the condition of electrical components can be analysed using performance data to determine when maintenance is required. This allows for greater ability to react to system problems before they progress to something more serious. - Cost
Whilst monitoring hardware and software can be costly to integrate, the value of the performance insights they provide are much greater. Information gathered from an EMS can be used to improve system efficiency, ultimately reducing operating costs. Advanced metering and monitoring technologies can allow for accurate costing analysis, this is useful for identifying and optimising panels that are causing financial strain. - Productivity
By analysing energy usage, organisations can easily identify areas of excessive energy consumption, where improvements may be required. This information may prompt system upgrades to reduce wastage, in turn increasing productivity levels. Aside from energy waste, unplanned downtime is another huge threat to business productivity. As previously mentioned, energy management systems can be used to identify potential threats to the system and predict maintenance requirement, ensuring continuity of service. - Environment
Reduced energy consumption also means reduced environmental impact, which is why many businesses are introduce EMS to support their sustainability policies. As the issue of sustainability continues to grow within the power distribution industry, many government agencies are offering financial incentives to businesses with efficient energy consumption levels.
