Tag: generator

DC Power(R)

Posted on by lechuck park

Data Center DC Power System Comprehensive Overview

This diagram illustrates the complete DC (Direct Current) power supply system for a data center infrastructure.

1. Core Components

① Power Source

  • 15.4 KV High Voltage AC Power
  • Received from utility grid
  • Efficient long-distance transmission (Efficient Delivery)
  • High voltage warning indicator (High Warning)

② Primary Transformer

  • Voltage conversion: 15.4 KV → 6.6 KV
  • Function: Steps down high voltage to medium voltage
  • Transformation method: Voltage Step-down
  • Adjusts voltage for internal data center distribution

③ Backup Power #1 – Generator System (Long-Time Backup)

  • Configuration: Diesel generator + Fuel tank
  • Characteristic: Long-duration backup capability
  • Purpose: Continuous power supply during main power outage
  • Advantage: Unlimited operation as long as fuel is supplied

④ Secondary Transformer

  • Voltage conversion: 6.6 KV → 380 V
  • Function: Steps down medium voltage to low voltage
  • Transformation method: Voltage Step-down
  • Provides appropriate voltage for UPS and final loads

⑤ Backup Power #2 – UPS System (Short-Time Backup)

  • Configuration: UPS + Battery
  • Characteristic: Short-duration instantaneous backup
  • Purpose: Ensures uninterrupted power during main-to-generator transition
  • Role: Supplies power during generator startup time (10-30 seconds)

⑥ Final Load (Power Use)

  • Output voltage: 220 V AC or 48 V DC
  • Target: Servers, network equipment, storage systems
  • Feature: Stable IT infrastructure operation with DC power

2. Voltage Conversion Flow

15.4 KV (AC)  →  6.6 KV (AC)  →  380 V (AC)  →  48 V (DC) / 220 V
  [Reception]   [Primary TX]   [Secondary TX]   [Final Conversion]

3. Redundant Backup Architecture

Two-Tier Backup System

Main Power (15.4 KV) ─────┐
                          ├──→ Transform ──→ Load
Generator (Long-term) ────┘
         ↓
    UPS/Battery (Short-term) ──→ Instantaneous uninterrupted guarantee

Backup Strategy:

  • Generator: Hours to days operation (fuel-dependent)
  • UPS: Minutes to tens of minutes operation (battery capacity-dependent)
  • Combined effect: UPS covers generator startup gap to achieve complete uninterrupted power

4. Operating Scenarios

Scenario 1: Normal Operation

Utility power (15.4KV) → Primary transform (6.6KV) → Secondary transform (380V) → UPS → DC load (48V)

Scenario 2: Momentary Power Outage

  1. Main power interruption detected (< 4ms)
  2. UPS battery immediately engaged
  3. Continuous power supply to load with zero interruption

Scenario 3: Extended Power Outage

  1. Main power interruption detected
  2. UPS battery immediately engaged (maintains uninterrupted power)
  3. Generator automatically starts (10-30 seconds required)
  4. Generator reaches rated capacity and replaces main power
  5. Generator power charges UPS + supplies load
  6. Long-term operation with continuous fuel supply

Scenario 4: Generator Failure

  • Limited-time operation within UPS battery capacity
  • Priority operation for critical systems or graceful shutdown

5. Additional Protection and Control Devices

Supplementary devices for system stability and safety:

Circuit Breaker Hierarchy

  • GCB (Generator Circuit Breaker): Primary protection at reception point
  • VCB (Vacuum Circuit Breaker): Vacuum interruption, medium voltage protection
  • ACB (Air Circuit Breaker): Low voltage distribution panel protection
  • MCCB (Molded Case Circuit Breaker): Individual load protection
  • Role: Circuit interruption during overload or short circuit to protect equipment and personnel

Switching Devices

  • STS (Static Transfer Switch): High-speed transfer between main power ↔ generator
  • ATS (Automatic Transfer Switch): Automatic transfer between power sources ( UPS level)
  • ALTS (Automatic Load Transfer Switch): Automatic load transfer ( for 22.9kV class)
  • CCTS: Circuit breaker control and transfer system
  • Role: Automatic/immediate transfer to backup power during power failure

Switching Points (Red circle indicators)

  • Reception point, before/after transformers, backup power injection points
  • Critical points for power path changes and redundancy implementation

6. Key System Features

✅ Uninterruptible Power Supply: Three-stage protection with main power → generator → UPS
✅ Multi-stage Voltage Conversion: Ensures both transmission efficiency and usage safety
✅ Automated Backup Transfer: Automatic switching without human intervention
✅ Hierarchical Protection: Stage-by-stage circuit breakers prevent cascading failures
✅ Scalable Architecture: Modular configuration enables easy capacity expansion

Summary

This DC power system architecture ensures continuous, uninterrupted operation of mission-critical data center infrastructure through a sophisticated combination of redundant power sources, automated failover mechanisms, and multi-layered protection systems. The integration of long-term generator backup and short-term UPS battery systems creates a seamless power continuity solution that can handle any grid interruption scenario. The multi-stage voltage transformation (15.4KV → 6.6KV → 380V → 48V DC) optimizes both transmission efficiency and end-user safety while providing flexibility for diverse IT equipment requirements.

#DataCenter #DCPower #PowerSystems #CriticalInfrastructure #UPS #BackupPower #DataCenterDesign #ElectricalEngineering #PowerDistribution #MissionCritical #DataCenterInfrastructure #FacilityManagement #PowerReliability #UninterruptiblePowerSupply #DataCenterOperations

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Emergency Power System

Posted on by lechuck park

This image shows a diagram of an Emergency Power System and the characteristics of each component.

Overall System Structure

At the top, the power grid is connected to servers/data centers, and three backup power options are presented in case of power supply interruption.

Three Backup Power Options

1. Generator

  • Long-term operation: Unlimited operation as long as fuel is available
  • Operation method: Engine rotation → Power generation
  • Type: Diesel engine generator
  • Disadvantages:
    • Start-up delay during instantaneous power outages
    • Start-up delay, noise, exhaust emissions
    • Periodic testing required
    • Requires integration with ATS (Automatic Transfer Switch)

2. Dynamic UPS

  • Features:
    • Uninterrupted/Long-term operation (until diesel engine starts)
    • Flywheel kinetic energy storage
    • Combined generator and diesel engine
  • Advantages: Seamless power supply without STS (Static Transfer Switch)
  • Disadvantages: High initial cost, large footprint, noise

DR (Diesel Rotary) UPS: A special form of Dynamic UPS that provides uninterrupted power through flywheel energy storage technology.

3. Static UPS

  • Operation time: Instantaneous/Short-term (typically 5-15 minutes)
  • Power quality: Clean power supply
  • Configuration: Battery(DC) → Inverter(AC) → Rectifier
  • Features:
    • Millisecond-level instant transfer
    • Battery life 3-5 years, replacement costs, heat generation issues

Key Characteristics Summary

Generators can operate long-term with fuel supply but have start-up delays, while Static UPS provides immediate power but only for short durations. Dynamic UPS (including DR UPS) is a hybrid solution that provides uninterrupted power through flywheel technology while enabling long-term operation when combined with diesel engines. In actual operations, it’s common to use these systems in combination, considering the advantages and disadvantages of each system.

With Claude

Power Flow

Posted on by lechuck park

Power Flow Diagram Analysis

This image illustrates a power flow diagram for a data center or server room, showing the sequential path of electricity from external power sources to the final server equipment.

Main Components:

  1. Intake: External power supply at 154 kV / 22.9 kV with 100MW(MVA) capacity
  2. Transformer: Performs voltage conversion (step down) to make power easier to handle
  3. Generator: Provides backup power during outages, connected to a fuel tank
  4. Transformer #2: Second voltage conversion, bringing power closer to usable voltage (220/380V)
  5. UPS/Battery: Uninterruptible Power Supply with battery backup for blackout protection, showing capacity (KVA) and backup time
  6. PDU/TOB: Power Distribution Unit for connecting to servers
  7. Server: Final power consumption equipment

Key Features:

  • Red circles indicate power switching/distribution points
  • Dotted lines show backup power connections
  • The bottom section details the characteristics of each component:
    • Intake power specifications
    • Voltage conversion information
    • Blackout readiness status
    • Server connection details
    • Power usage status

Summary:

This diagram represents the complete power infrastructure of a data center, illustrating how electricity flows from the grid through multiple transformation and backup systems before reaching the servers. It demonstrates the redundancy measures implemented to ensure continuous operation during power outages, including generators and UPS systems. The power path includes necessary voltage step-down transformations to convert high-voltage grid power to server-appropriate voltages, with switching and distribution points throughout the system. This comprehensive power flow design ensures reliable, uninterrupted power delivery critical for data center operations.

With Claude