Balancing – Active and Passive

 

The act of bringing the voltage of serially connected cells to within a tolerance of each other. The goal of balancing is to equalize discharging between cells and optimize the life of the group. Methods include “active” and “passive”.

 

Battery Management System

 

A control system governing the charge, discharge, temperature, current, and voltage of a battery module or pack

 

Battery – Cell

 

A chemical system that produces DC voltage

 

Battery – Module

 

A series parallel arrangement of cells including module level battery management controls

 

Battery – Pack

 

A series parallel combination of modules including pack level battery management controls

 

Black start

 

Returning a generation asset to operation without relying on the external electric power transmission network.

 

Blackout

 

Total cut out of an electrical power supply.

 

BMS

 

Battery Management System. Device attached to each Durathom Module to manage its performance and operation.

 

Brownout

 

Intentional drop in voltage in an electrical power supply system in order to reduce load in an emergency.

 

C Rate

 

The charge or discharge rate relative to a full charge or full discharge in 1 Hour. For example if a battery is discharged in 30 minutes the C rate is 2.

 

Capacity factor

 

Ratio of the actual output of a power plant over a period of time and its potential output if it had operated at full nameplate capacity.

 

CDC

 

Charge-Discharge-Cycle; operating the battery continuously alternating between charge and discharge in partial state of charge to optimize the battery energy throughput.

 

Congestion

 

When the electricity load exceeds the maximum capacity of the transmission system.

 

Constant Current Charge

 

The beginning portion of a battery’s charging profile where the charging current is fixed and the charging voltage is dependent on the battery’s state of charge.

 

Constant Power Charge Mode

 

A fixed kW power charge level.

 

Constant Power Discharge Mode

 

A fixed kW power discharge level.

 

Constant Voltage

 

The final portion of a battery’s charging profile where the charging voltage is fixed near the battery’s maximum voltage and the charging current is dependent on the battery’s state of charge.

 

Current Transformer

 

An instrumentation transformer used to scale down a large current on the primary side to a smaller current on the secondary side which is measurable by another device.

 

Demand Response

 

Demand Response programs offer incentives to electricity users to reduce their power use in RESPONSE to a utility's need for power due to a high, system-wide DEMAND for electricity or emergencies that could affect the transmission grid.

 

DER

 

Distributed Energy Resources.

 

Digital peaker

 

Energy storage asset that is primarily used to provide power during periods of peak demand.

 

DMS

 

Distribution Management System.

 

DOD

 

Depth of Discharge.

 

DSO

 

Distribution Service Operator.

 

Durathon Module

 

The basic building block of the Durathon Energy Storage System.

 

Electromagnetic Interference

 

A disturbance that affects an electrical circuit.

 

Energy arbitrage

 

Storing energy at one time of day and then discharging at another time, effectively shifting energy from one time to another. Most commonly used in renewables where energy is generated and stored off peak and then delivered during peak times. (see shifting)

 

Energy time shift

 

Storing energy at one time of day and then discharging at another time, effectively shifting energy from one time to another. Most commonly used in renewables where energy is generated and stored off peak and then delivered during peak times. (see shifting)

 

Firming

 

Using storage to "fill in" gaps in intermittent renewable power generation so the power supplied looks somewhat to very constant.

 

Flicker

 

Utility industry term describing the very short term effect on power quality caused at the start of a load.

 

Frequency response

 

Response taken by interconnected party to address imbalances in frequency on an electric grid.

 

Grid Synchronization

 

While in island mode with the isolation contactor open, the act of aligning the inverter’s output voltage and frequency (point-to-point) with those of the AC utility prior to closing the contactor.

 

Grid Tie Inverter

 

A grid tie (synchronous) inverter changes DC to AC and either sends energy back to the utility company or for immediate use by the home or business owner.

 

HV network

 

High voltage network – typical voltage above 50kV.

 

Interconnection rules

 

Rules and regulations that an entity connecting to an electricity grid must meet. Often concerned with ensuring safety and security of supply.

 

IPP

 

Independent Power Producer.

 

Island Mode

 

System could detect abnormal utility conditions, open contactor, and serve customers in an island. When the utility is restored, will re-synchronize and re-connect.

 

Islanding

 

A self contained electric grid which has no or just limited connection to a large electrical network.

 

KW

 

Kilowatt. Unit of Power.

 

KWH

 

Kilowatt Hour. Unit of Energy.

 

Load Management

 

The active process of balancing the supply of electricity on the network with the load by adjusting or controlling the load.

 

LV network

 

Low voltage network – typical voltage range less than 1kV.

 

Monthly Demand Charge

 

A charge for the maximum rate at which energy is used during peak hours of a billing period. That part of a power provider service charged for on the basis of the possible demand as distinguished from the energy actually consumed. $/kW paid monthly On Peak Energy Price Retail price of Energy supplied during periods of relatively high system demands as specified by the supplier. ($/kWh) Off Peak Energy Price Retail price of Energy supplied during periods of relatively low system demands as specified by the supplier. ($/kWh)

 

MV network

 

Medium voltage network – typical voltage 1kV- 50kV.

 

Peak lopping

 

Reducing a user's effective peak load by using storage discharge to augment power delivered by the grid (see peak shaving).

 

Peak management

 

Reducing a user's effective peak load by using storage discharge to augment power delivered by the grid (see peak shaving)

 

Peak Shaving

 

The process of utilizing alternative energy sources to meet customer demand during peak-use periods.

 

Peaking capacity

 

Using storage to deliver relatively rapid power to the grid at times of high load where additional capacity, over base capacity, is needed.

 

Power factor

 

The ratio of the real power flowing to the load to the apparent power in the circuit.

 

Power Factor Correction

 

The process of supplying reactive power to the load in order to bring the power factor of the circuit closer to 1.0.

 

Power quality

 

The overall quality of electric power. Affected by voltage, frequency, power factor, and harmonics.

 

PSOC

 

Partial State of Charge.

 

Rate Arbitrage

 

The practice of profiting through the volatility of energy market prices, brought on by significant changes in daily supply and demand.

 

Rated Power

 

The total possible output from the energy storage system, expressed in kW.

 

Reactive Power

 

The “phantom power” of reactive loads such as inductors and capacitors measured in Volt-Amps-Reactive (VAR).

 

RES

 

Renewable Energy Sources.

 

Residual power availability

 

The remaining energy available at the lower state of charge limit in a partial state of charge operating window.

 

Shifting

 

Storing energy at one time of day and then discharging at another time, effectively shifting energy from one time to another. Most commonly used in renewables where energy is generated and stored off peak and then delivered during peak times.

 

Smoothing

 

Process to ensure that rapid changes output energy from solar and wind generation can be effectively managed on a utilities grid.

 

SOC

 

State of Charge.

 

Spinning reserve

 

On-line reserve capacity that is synchronized to the grid system and ready to meet electric demand within 10 minutes response time.

 

State-of-Charge

 

The amount of energy remaining in a battery relative to a full charge.

 

Transmission congestion

 

Occurs when electrical load exceeds transmission capacity in a given area.