PureWave® Storage Management System
With the increase in wind, concentrated solar, and other renewable energy sources in the overall generation mix, it’s essential that these variable sources be made more dispatchable, so that more renewable energy is available to the grid. One way to accomplish this goal is to store the energy during off-peak demand times, and then discharge the energy into the grid during peak demand times.
PureWave Storage Management System offers megawatt-hours of energy storage for Smart Grid applications, permitting this power to be dispatched when it’s needed. Power generated off-peak can be used during periods of peak usage, dramatically reducing the greenhouse gases produced by traditional generating sources, and displacing peak energy costs with off-peak costs.
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Features
The PureWave Storage Management System provides an interface between a stored power source and the utility grid. It consists of a master control system and a 2-MW/2.5-MVA power conversion system (PCS). The PCS is comprised of two inverters, each rated 1 MW/1.25 MVA. When coupled with stored energy, the PureWave SMS can charge the storage device from a utility source, or discharge the storage device to the utility source. When connected to a feeder, the PureWave SMS can supply VARs in response to an external command, or hold feeder voltage at a preset level. The PureWave SMS can also operate independently, supplying power to a load that is not connected to the utility.
- Megawatt-hours of energy storage for Smart Grid applications
- Very high efficiency
- Fully digital control system
- Better utilization of renewable energy
- With S&C’s IntelliTeam® SG Automatic Restoration System, provides dynamic islanding capability
- Automatic or remote SCADA control
- Turnkey installation and project management for smooth integration into utility system
Individual PureWave SMS units can be operated in parallel up to 20.0 MW/25 MVA, with the outputs of the units connected to a common bus at medium voltage. Two or four PureWave SMSs are housed in a single ISO container for outdoor installation. Each 2-MW block contains two dc circuit breakers, two ac circuit breakers, two PCSs and controls. The output of the PCS is a 480-V delta connection that can be connected to a delta or wye transformer. If it is necessary to supply single-phase loads when the utility source is not present, a delta connection must be used.
Ratings
| Current Source AC Ratings | |
|---|---|
| Power Nominal, Per Inverter | -1 MW (charge) to +1 MW (discharge) |
| VA Nominal, Per Inverter | 1.25 MVA |
| Voltage | 480 Vac ±10% |
| Current Nominal | 1504 A |
| Frequency Range | 58.5 to 61 Hz or 48.5 to 51 Hz |
| Current Harmonics | Less than 5% of nominal current if voltage distortion is less than 5% |
| Voltage Source AC Ratings | |
|---|---|
| Power Maximum | 2.0 MW |
| VA Maximum | 2.5 MVA |
| Voltage | 480 Vac ±3% |
| Current Maximum | 3008 A |
| Frequency | 60 Hz ±0.1 Hz |
| Voltage Harmonics | Less than 3% if load current harmonic distortion is below 5% |
| DC Input Ratings (each of the two inputs) | |
|---|---|
| Voltage | 460 Vdc to 800 Vdc |
| Current in Current Source Mode | -1145 A dc (charge) to 1150 A dc (discharge) |
| Current in Voltage Source Mode | 0 to 1374 A dc (discharge—up to 100 seconds above 1 MW) |
| Ripple Current | Typical |
| Ripple Voltage | Less than 4 volts RMS |
| Environmental Ratings | |
|---|---|
| Temperature | -40°C to +40°C without derating |
| Humidity | 0 to 100% condensing, including rain |
| Maximum Altitude | 1000 Meters without derating |
| Seismic Rating | Zone 4 |
| Control Power Backup | UPS, minimum 5-minute backup of all controls needed for data and control of PCS |
| Time | |
|---|---|
| Time Source | Integrated GPS. An offset from UTC can be applied to move to local time |
Applications
PureWave SMS for Renewable Energy. Solar and wind energy are intermittent power sources that the grid must accept whenever available. During absences of sun or wind — when these sources are not generating — replacement power must be provided. The PureWave SMS can store the power when it’s produced, and then use that energy for generation ramp-rate control, output-smoothing, or time-shifting.
Grid-Scale Energy Storage. The PureWave SMS can deliver up to 2 MW of stored energy to the grid from any type of battery storage system.
Islanding. When applied with S&C’s IntelliTeam® SG Automatic Restoration System, the PureWave SMS can be used in remote areas, as an energy source during power outages. Upon loss of utility power, IntelliTeam SG re-configures the distribution system and uses the stored energy to serve local customers — now isolated from the utility — for as long as 7 hours.
Peak Shaving. During high demand periods, the PureWave SMS can provide full output for up to 7 hours. This reduces the system peak, deferring the need for capacity additions on the distribution or transmission system.
Installations
Below are a few examples of PureWave SMS installations completed S&C.
Customer: American Electric Power (AEP)
Project Location: Presidio, Texas
In-service Date: September, 2010
Project Description:
- 4 MW, 24 MW-hour Sodium-Sulfur Battery Storage System
- Turnkey Installation by S&C Power Systems Services
- Peak Shaving and Islanding
- IntelliRupter® PulseClosers reconfigure the system during islanded operation
Customer: American Electric Power (AEP)
Project Location: Chemical Substation, Charleston, West Virginia
In-service Date: June, 2006
Project Description:
- 1.0 MW, 7.2 MW-hour Sodium-Sulfur Battery Storage System
- Turnkey installation by S&C Power Systems Services
- Peak Shaving for 20 MVA Station Transformer
Customer: American Electric Power (AEP)
Project Location: Balls Gap (future substation), Milton, West Virginia
In-service Date: November, 2008
Project Description:
- 2 MW, 12 MW-hour Sodium-Sulfur Battery Storage System
- Turnkey installation by S&C Power Systems Services
- Peak Shaving and Islanding Demonstration with IntelliTeam® II Automatic Restoration System controls
Customer: American Electric Power (AEP)
Project Location: Citizens Substation, Bluffton, Ohio
In-service Date: October, 2008
Project Description:
- 2 MW, 12 MW-hour Sodium-Sulfur Battery Storage System
- Turnkey Installation by S&C Power Systems Services
- Peak Shaving and Islanding
Customer: American Electric Power (AEP)
Project Location: East Busco Substation, Churubusco, Indiana
In-service Date: December, 2008
Project Description:
- 2 MW, 12 MW-hour Sodium-Sulfur Battery Storage System
- Turnkey Installation by S&C Power Systems Services
- Peak Shaving and Islanding
Customer: XCEL Energy
Project Location: Rock County Substation, Beaver Creek, Minnesota
In-service Date: November, 2008
Project Description:
- 1 MW, 6 MW-hour Sodium-Sulfur Battery Storage System
- Turnkey Installation by S&C Power Systems Services
- Peak Shaving, Wind Farm Output Smoothing, Energy Dispatching and Arbitrage