Insurance Considerations Cost of Outage vs. Cost of Insurance Consider 5 year to 10 year life cycle cost Do Not Forget Maintenance Costs Which Energy Storage Technology is Best Suited for the Application?
Battery Technologies: 10 Year VRLA –A.k.a. Maintenance Free, Gel Cell, AGM –3 to 7 year life on most UPSs –Fails in open or shorted position –Low cost, most prevalent
Conventional Grid Design Improved High Rate Grid Design
Battery Technologies: 20 Year Sealed VRLA –12 to 18 year life (depending on number of outages; environment) –Fails in shorted position –About 2x initial cost of 10Year VRLA
Battery Technologies: 20 Year Wet Cell –17 to 20 year life –Very reliable –High maintenance, large footprint, eye wash station… –About 3x initial cost of 10 Year VRLA
Battery Maintenance IEEE Std Recommended Practice for Maintenance, Testing, and Replacement of Valve-Regulated Lead-Acid (VRLA) Batteries for Stationary Applications –Monthly: float voltage, charger output, temperature measurements –Quarterly: cell/unit ohmic values; temperature value of each negative terminal; representative sample of intercell connection resistances –Annually: cell-to-cell and terminal connection detail resistance of the entire battery; AC ripple current and/or voltage imposed on the battery
Battery Monitoring More Prevalent Real Time Status of Batteries Monitors: Impedance, Temperature, and Float Charging Voltage Cost = $6k to $10k per system (installed)
Other Energy Storage Technologies Flywheels Ultracapacitors Lithium Ion Batteries Thermal and Compressed Air Storage
UPS Electronics Trends
AC DC 6-Pulse Rectifier AC DC Inverter Static Bypass Batteries Input Filter Typical Double Conversion UPS Oneline
DIODE DIODE THYRISTOR IGBT IGBT:INSULATED GATE BIPOLAR TRANSISTOR The Evolution of the Rectifier/Converter Device
The Evolution of the Converter (Rectifier) Circuit 6 PULSE CONV. 12 PULSE CONV. PWM CONV. PWM CONV.:PULSE WIDTH MODULATION CONVERTER CONV.:CONVERTER
6 PULSE RECTIFIER CIRCUIT AND INPUT CURRENT WAVEFORM Ic
. Id 12 PULSE RECTIFIER CIRCUIT AND INPUT CURRENT WAVEFORM Ic
.18 PWM THREE PHASE PWM CONVERTER CIRCUIT L C P N Sine Wave Form (pf=1.0) AC Input Current AC Input Voltage
PWM CONVERTER (2) The input power factor is UNITY (1.0) with PWM converter 0.8 – 0.85 with Thyristor rectifier
Results of IGBT Converter Generator Sizing Dependant Upon UPS Input Requirements Linear Current Draw = Smaller Generator IEEE 519 – Low Current Harmonics at Utility Source
INVERTER POWER DEVICE HISTORY THYRISTOR G T O IGBT BPT GTO:GATE TURN OFF THYRISTOR BPT:BIPOLAR POWER TRANSISTOR IGBT:INSULATED GATE BIPOLAR TRANSISTOR
High Speed PWM Inverter Improved output control characteristics resulting from the use of a high speed PWM inverter 16kHz Switching Frequency Supports nonlinear loads with minimal voltage distortion
IGBT CONV IGBT INV ALL IGBT UPS
Also…Improving Efficiencies UPS efficiencies are up 10% over the past 15 years Most large UPS systems are currently over 93% efficient In Years, Most Large UPS Systems Will Be > 97% Efficient
Other Trends… Higher Output Power Factor on UPS –Match trends in the Computer Power Supply Market Internal Redundancy/Scalability for High 9s Applications –Avoid Single Points of Failure –Maintain High Efficiency
What does all this mean? Its dependant on your susceptibility. Given the quality of supply do I have to worry about problems with my equipment or systems?
What you should be asking… What is my susceptibility to power problems? What is my economic exposure to such problems? $$$$$$
The big picture… Its the complete electrical environment, not just the quality of supply.
What you should be asking… Does my power system have the capacity for my present needs? How about future growth? Be proactive!
Thank you for your time! Chuck Barry Central Region Sales Manager Toshiba UPS 8711 Burnet Road, Suite E-55 Austin, TX Tel. (512)