3 Phase & 1 Phase UPS

Robert Lyga Gamatronics

Agenda • Module 1 – Modular UPS technology-3-Phase

– Basics of Modular UPS technology – Centralized vs Decentralized Battery – Planning for Capacity and Future Growth – N+1 Redundancy Methods – Modular UPS vs Single Size UPS – Reliability/Maintenance of Today’s Modular Systems

• Module 2 – Single Phase Technology

– Methods of achieving long run times – Charging batteries in multiple battery packs

Basics of Modular UPS Technologies • Traditional UPS consists of single rectifier and

inverter sized for full capacity of UPS. – System may not be upgradeable for future expansion

• Replacement with larger system required • High cost of expansion

– System may need to be oversized today for correct size in future

• Higher cost of UPS today • Lower efficiency and higher Cost of Operation while

undersized – Failure of the rectifier or inverter transfers the loads to

static bypass • Lower reliability due to single points of failure • Redundancy can be done but at a higher cost

Rectifier Inverter

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80kVA

Basics of Modular UPS Technologies • Today’s modular UPS system

– Can be configured from 10kVA to 100kVA • 10kVA to 12kVA power modules • UPS capacity based on the # of modules • Modules can be added to increase capacity, redundancy, or

charging

– Each module contains rectifier and inverter – Control system may be in each module or at system

level • Module level control with master – slave relationship

Basics of Modular UPS Technologies • Modular UPS consists of multiple, smaller

rectifier/inverter modules. – System can be upgraded with addition of power modules as

loads grow

• System does not have to be replaced

• Lower cost of expansion

– Customer purchases the correct size UPS today and the UPS can grow as needed.

• Lower initial investment

• UPS can be operated at % load that give the best efficiency and operating cost

– One rectifier or inverter may fail without causing the UPS to transfer the loads to static bypass

• Remaining modules may support the load

• Higher reliability due to lack of single point of failure

• Redundancy can be done at lower cost at the module level

80kVA

Centralized vs Decentralized Battery • Centralized Battery

Centralized vs Decentralized Battery • Centralized Battery

– Batteries are charge simultaneously by all modules, independent of the integrity of the individual modules

– Backup time not affected by faulty module

– Optional addition of battery strings in parallel

– High reliability

– Charge current control and monitoring according to battery capacity

– Operation unaffected by rectifier failure in one of the modules

Centralized vs Decentralized Battery • Decentralized Battery

Centralized vs Decentralized Battery • Decentralized Battery

– End-of-discharge disconnection voltage is determined by the weakest battery set.

– An inverter failure in one of the modules reduces the backup time

– A rectifier failure in one of the modules excludes its battery set as well as its inverter output.

– Over current condition may develop in the remaining battery sets in case of a module failure

– Problematic maintenance of multiple battery sets (hundreds of batteries per system!)

– Downgrade of battery reliability due to so many batteries that are liable to fail

Planning for Capacity and Future Growth • Planning for Capacity

– Determine the amount of load as normal

• Consider start surges and periodic loads as needed

– Select a UPS size based on current capacity requirements

– Select battery system to meet runtime needs.

– Determine the type of maintenance bypass required

Planning for Capacity and Future Growth • Planning for Future Growth

– Select UPS chassis that is scalable to future needs

– Select battery system that is scalable or with proper over current protection

– Size maintenance bypass to allow UPS growth

– Size wiring for future capacity

N+1 Redundancy Methods • Single Size UPS

2 units of 80kVA provide N+1 Redundancy

N+1 Redundancy Methods • Single Size UPS

– High initial capital cost • Must Purchase 2 large UPS system

– High installation cost • Must install 2 systems

– Lower efficiency = higher operating cost • Systems operating at 50% load

– 2X footprint • Floor space may not be available

• Square foot cost

N+1 Redundancy Methods • Modular UPS

8 x 10kVA for Capacity plus 1 x 10kVA for N+1 Redundancy

+ 10kVA

10kVA

10kVA

10kVA

10kVA

10kVA

10kVA

10kVA

10kVA

80kVA

N+1 Redundancy Methods • Modular UPS

– Low initial capital cost • Add one additional module for N+1 redundancy

– Lower installation cost • Install a single UPS system

– Lower efficiency = higher operating cost • All modules operating at higher % load

– Single UPS footprint • Lower floor space costs

Reliability / Maintenance of Today’s Modular Systems

• Reliability – Scalability allows operation at optimal % load

– N+1 redundancy increases system reliability

• Maintenance – Achieved on modular lever

– Lower MTTR

– Lower labor costs for repair

– Spare parts = spare module

Single Phase UPS Technologies

• Methods of achieving long runtimes – Single battery systems with large wpc batteries

• Typical for larger single phase UPS

• May not be available for smaller UPS

• High initial cost

• Difficult to add incremental runtime

• May require a large charger

Single Phase UPS Technologies

• Methods of achieving long runtimes – Multiple external battery packs (EBP)

• Typical for smaller UPS

• Use smaller wpc batteries in each pack

• Lower initial cost

• Can add incremental runtime

• Charging method dependant on system

Single Phase UPS Technologies

• Methods of achieving long runtimes – Multiple external battery packs (EBP)

Single Phase UPS Technologies

• Charging batteries in multiple battery packs – Single charger in UPS

• May be too small for total battery

• Battery packs may receive different charge voltage and current

– Chargers in each battery pack • Charger sized correctly for the pack

• Each pack receives correct current and voltage

Single Phase UPS Technologies

• Charging batteries in multiple battery packs – Chargers in each battery pack

Questions?