Online Glossary

Term Description
AMI Advanced Metering Infrastructure (AMI) refers to systems that measure, collect, and analyze energy usage, and communicate with metering devices such as electricity meters, gas meters, heat meters, and water meters, either on request or on a schedule. These systems include hardware, software, communications, consumer energy displays and controllers, customer associated systems, meter data management software, and supplier business systems.
AMM Advanced Metering Management
AMR Automated Meter Reading, systems responsible for handling tasks that require communication with metering devices, for example reading of metering values.
ANSI American National Standards Institute
COSEM Companion Specification for Energy Metering, specifications required in addition to DLMS, which describe the interface to the meter.
CT Current transformer. An alternating current device which reduces actual current flow through meter with a fixed ratio.
CT Ratio The relationship of a current transformers’ primary to secondary rating. This ratio defines the multiplication factor that has to be applied to the meter output in order to obtain the actual metered amount
Demand Interval The interval of time over which a demand measurement is taken. Common intervals: 10, 15, 30, or 60 minutes.
Disconnector A relay that can turn off power to a whole house or other metered electric service. In some cases, it can be operated remotely.
DLMS Device Language Message Specification. This specification provides an environment for structured modelling and meter data exchange. Applications such as remote meter reading, remote control and value added services for metering any kind of energy (electricity, water, gas, and heat) are supported. Managed by DLMS UA.
DSM Demand side management. This is a means to control energy consumption and to optimise network usage via tariff control and/or load control. Both can be controlled via ripple control signals (PLC) and radio signals. DSM encourages consumers to modify patterns of electricity usage, including the timing and level of electricity demand.
EMC Electromagnetic Compatibility is concerned with the unintentional generation, propagation and reception of electromagnetical energy and with the unwanted effects that such an energy may induce. In particular, the aim of EMC is the correct operation, in the same environment, of different equipments which involve electromagnetic phenomena in their operation.
IEC International Electrotechnical Commission, an international standards organization dealing with electrical, electronic and related technologies.
ISO International Standardization Organisation, an international-standard-setting body
KEMA Keuring van Elektrotechnische Materialen te Arnhem, established in 1927, was a global energy consultancy company headquartered in Arnhem, Netherlands. It is the leading international certification and testing lab in the world.
Load Control Activities performed by the utility that can interrupt load at the time of peak by interrupting power supply on consumer premises. Load control is usually applied to residential consumers.
Load Management Utility activities designed to influence the timing and amount of electricity that customers may use.
Load Profile Hourly or sub-hourly pattern of energy use. It is stored as a list of time stamped power data and is sometimes shown as a graph depicting the power consumption over a specific period.
Load Shedding The process of deliberately removing (either manually or automatically) preselected customer demand from a power system in response to an abnormal condition to maintain the integrity of the system and minimize overall customer outages.
Maximum Demand The highest demand measured over a designated period of time, e.g. one month typically.
M-Bus The M-Bus, also called Meter Bus, was produced from the necessity to interlink a large number of consumption measuring units, such as electricity, water, gas or heat meters over a long section at low cost to permit communication with a central station, i.e. to read meter data or to perform service functions (setting starting values, time/date, etc.). The central station computer (PC) together with a repeater connected to its RS232 interface forms the M-Bus master. Up to 250 meters can be connected to the repeater as M-Bus slaves.
Meter Constant The meter constant is a factor applied to the output of a meter to obtain the desired units of measure. In Ferraris-meters, it represents the number of revolutions for 1 kWh. In electronic meters, it defines how many times the Test-LED flashes per 1 kWh.
OBIS OBject Identification System, defines identification codes for all data in DLMS/COSEM compliant metering equipment.
PLC Power Line Communication, a system for carrying data on a conductor also used for electric power transmission.
Power Factor The power factor of an AC electric power system is defined as the ratio of the real power to the apparent power.
Prepayment Meters Prepayment meters are electric meters that allow the customer to pay a specified amount of money in advance of service to guarantee some level of minimum service while allowing low-income customers to keep within their budget.
Reverse Energy Energy that flows from the consumer back to the utility supplier, e.g. generated by solar panels on the consumer’s premises.
Smart Meters Devices with a range of extra functions. A smart meter will be able to record not only how much energy was used, but also when it was used. This enables different electricity rates for different times of the day to encourage customers to regulate their own usage of electricity during peak times. There are basically two types of smart meters: “Time Of Use” meters and interval meters.
Solid State Meter Digital/electronic metering device.
Time-of-Use (TOU) Meters A type of meter that measures and stores consumption and specific times of the day. These meters have lower costs to purchase and to read, and low-end versions cannot be remotely reprogrammed and cannot communicate in real time. Any changes to rate “buckets?requires the meter to be returned to the manufacturer and a new verification seal has to be applied.
THD The Total Harmonic Distortion of a signal is a measurement of the harmonic distortion present and is defined as the ratio of the sum of the powers of all harmonic components to the power of the fundamental.
TOU Time-of-Use tables facilitate load control and planning on the part of utilities. This involves dividing the day, month and year into tariff slots and with higher rates at peak load periods and low tariff rates at off-peak load periods. The TOU table can also be used for load control, signal generation, etc.