UPS Topologies and Multi Module Configurations IEEE IAS
- Slides: 37
UPS Topologies and Multi. Module Configurations IEEE IAS Section Atlanta GA November 17, 2008
Agenda UPS Topologies Line Interactive UPS Delta Conversion UPS Double Conversion UPS Rotary UPS Design Market Drivers UPS Components Multi-Module UPS Configurations 2/ / 10/26/2020
Critical Power System Generation Power Quality TVSS Distribution UPS Static Switch PDU Critical Load Servers ATS Paralleling Switchgear 3/ / 10/26/2020
Line Interactive UPS 4/ / 10/26/2020
UPS Topologies – Line Interactive Runs on AC power from Utility and switches to Inverter if Utility source power quality is not within predetermined tolerance. Provides some surge protection. Benefits – very efficient due to minimizing inverter run time Disadvantages – limited surge protection Application – Single computer or single rack 5/ / 10/26/2020
Delta Conversion 6/ / 10/26/2020
Delta Conversion This Line Interactive system carries the load by using both the utility line by means of a Line Conditioner (Course Regulation) and two converters (Actually two inverters for Fine Regulation & Battery Charger). This topology can regulate the load voltage by manipulating the secondary winding of the series t -former using the Series Converter. Advantages • System does not go on battery for voltage fluctuations. • System efficiency is higher in normal mode. Disadvantages • The unit needs two inverters, less reliability. • It circulates more ripple current to the batteries. • If the utility frequency goes out of tolerance, the unit must go on batteries. 7/ / 10/26/2020
Double Conversion UPS 8/ / 10/26/2020
UPS Topologies – Double Conversion Rectifies AC power into DC and then converts the DC back to AC. Provides clean power, completely isolated from the Utility during normal operation. Benefits – No interruption of Power; Protects load from Utility spikes and Surges Disadvantages – Greater losses than Line Interactive design 9/ / 10/26/2020
Rotary UPS 10 / / 10/26/2020
UPS Design Key Market Drivers Reliability – The 5 “ 9’s” - 99. 999% up time Efficiency EPA Influence Green Grid Server Technology Voltage Outage Ride Through 11 / / 10/26/2020
Efficiency Line Interactive UPS ~98% efficient Double Conversion ~ 92% to 94% efficient Methods to improve UPS efficiency Eliminate Input and Output Transformers “ECO” mode -Line interactive mode of operation Data Center Efficiency Trends Eliminate PDU transformers Electrical Distribution Voltages 12 / / 10/26/2020
ECO Mode Overview 13 / / 10/26/2020
Server Technology Server Voltages Today – 120 VAC - 240 VAC 600 V or 480 V distribution with PDU transformers 400 V distribution without PDU transformers Future – 277 VAC? ; 480 VAC? Server Power Outage Ride Through CEMBA Curve – Now the “ITIC” Curve Key Factor for “ECO” mode. 14 / / 10/26/2020
CBEMA-ITIC Curve for Double Conversion UPS 15 / / 10/26/2020
UPS Components Rectifiers SCR or IGBT SCR – 6 Pulse and 12 Pulse Inverters IGBT with PWM Static Switch Module Transformers Input Transformer Output Transformer Filters Input Harmonic Filters 16 / / 10/26/2020
Rectifiers IGBT Rectifier – Clean Input High power sinusoidal rectification – low harmonics, limited need for filters SCR Rectifiers 6 Pulse – ~30% THD without filters – 7% with 5 th Harmonic Filter <5% with 5 th and 11 th filter 12 Pulse – reduces harmonics by using parallel rectifiers with a phase shift ahead of one rectifier – requires input transformer • Rectifiers can be programmed to sequentially ramp up Lower efficiency than 6 Pulse 17 / / 10/26/2020
6 Pulse Current Input THD without filter THD with filter 18 / / 10/26/2020
12 Pulse Rectifiers 19 / / 10/26/2020
750 k. VA - 6 P vs 12 P Rectifier – Energy Efficiency 25% 6 -Pulse no Xfrmr 92. 8 % 12 -Pulse w/xfrmr 91. 8 % 50% 94. 2 % 93. 3 % 0. 9 % 75% 94. 2 % 93. 2 % 1. 0 % 100% 93. 6 % 92. 4 % 1. 2 % Percentage load Difference 1. 0 % 20 / / 10/26/2020
Inverters Converts DC power into AC using IGBTs and PWM Several different methods to implement PWM 21 / / 10/26/2020
Static Switch Modules Static Switch Module consists of breaker or contactor in series with back to back SCRs. Static Switch modules can be continuous duty or momentary rated. Momentary rated Modules have a breaker or contactor in parallel. Continuous duty is required for ECO mode operation. 22 / / 10/26/2020
Input Isolation Transformer – required for 12 Pulse Rectifier 23 / / 10/26/2020
UPS Output Transformer - Isolates load from inverter - Provides greater protection to load during inverter failure - Transformer MTBF > IGBT MTBF 24 / / 10/26/2020
Input Filters 5 th Harmonic Cancellation • The filter is designed to cancel the current distortion that is most present on the 5 th harmonic. Power Factor Correction • The input filter also raises the input pf to approximately 0. 93 with addition of capacitors. This will allow the generator to operate more efficiently delivering more real power 25 / / 10/26/2020
Multi-Module UPS Configurations Paralleling UPS Modules Capacity or Redundancy Centralized Bypass Distributed Bypass Typical Parallel UPS Configurations Isolated Redundant Parallel Redundant Distributed Redundant System plus System 26 / / 10/26/2020
Parallel for Capacity Multiple units = N Not recommended for a N System (single system) Frequently used for System + System (N+N) MTBF impact Parallel for capacity reduces MTBF value Approximately half the MTBF of a single unit 27 / / 10/26/2020
Centralized Bypass 28 / / 10/26/2020
Distributed Bypass 29 29 / / 10/26/2020
Centralized Bypass Cabinet Distributed Bypass Configuration does not need this gear lineup 30 / / 10/26/2020
Parallel UPS Configurations Isolated Redundant Parallel Redundant Distributed Redundant System plus System 31 / / 10/26/2020
Isolated Redundant 32 / / 10/26/2020
Parallel Redundant 33 / / 10/26/2020
Distributed Redundant 34 / / 10/26/2020
System + System 35 / / 10/26/2020
Questions? 36 / / 10/26/2020
Contact Information: Harry Handlin GE Power Quality Systems Engineer P 205 -789 -7479 E harry. handlin@ge. com 37 / / 10/26/2020