Energy saving opportunities - Designing information and monitoring systems
From Electrical Installation Guide
In reality, systems for monitoring and energy control are physically very similar and overlap with the electrical distribution architecture whose layout they often replicate.The arrangements shown in Figure K20 to Figure K24 represent possible examples and reflect the requirements typically associated with the distribution involved (in terms of feeder numbers, the amount and quality of energy required, digital networks, management mode, etc.). They help to visualise and explain all the various services which can be used to promote energy efficiency.
Fig. K20: Monitoring architecture for a small site which only supports sub-metering
Fig. K21: Monitoring and control architecture for a company with several small sites
Fig. K22: Architecture for large multiple-site arrangements
Fig. K23: Monitoring and control architecture for a large, sensitive industrial site
Fig. K24: Architecture for a large service-industry site
In addition, these diagrams make it clear that the choice of components is determined by the choice of architecture (for example, the sensors must be right for the digital bus). The reverse also applies, however, since the initial choice of architecture may be affected by a technological/economic assessment of component installation and the results sought. In fact, the cost (in terms of purchase and installation) of these components, which sometimes have the same name but different characteristics, may vary widely and produce very variable results:
- A measuring device can measure one or more parameters with or without using calculations (energy, power, cos ϕ).
- Replacing a standard circuit breaker with a circuit breaker containing an electronic control unit can provide a great deal of information on a digital bus (effective and instantaneous measurements of currents, phase-to-neutral and phase-to-phase voltages, imbalances of phase currents and phase-to-phase voltages, frequency, total or phase-specific active and reactive power, etc.).
When designing these systems, therefore, it is very important to define objectives for energy efficiency and be familiar with all the technological solutions, including their respective advantages, disadvantages and any restrictions affecting their application (see Fig. K27).
To cover all the various scenarios, it may be necessary to search through various hardware catalogues or simply consult a manufacturer offering a wide range of electrical distribution equipment and information systems. Certain manufacturers, including Schneider Electric, offer advisory and research services to assist those looking to select and implement all these various pieces of equipment.
|Energy savings||Cost optimisation||Availability and reliability|
|Variable speed drives|
|High-performance motors and transformers|
|Supply for MV motors|
|Power factor correction|
|Outage-free supply devices|
|Architecture based on intelligent equipment Level 1|
|Specialised, centralised architecture for electricians Level 2|
|General/conventional, centralised architecture Level 3|
Fig. K27: Solutions chart