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- APC Back UPS
- APC EASY UPS
- APC Modular UPS
- APC Smart SMC UPS
- APC Smart SMT UPS
- APC Smart SURT UPS
- APC SPM UPS
- APC Symmetra Power Module
- APC SYMMETRA LX
- APC Symmetra PX
- Eaton 5P UPS
- Eaton 5PX G2 UPS
- Eaton 93PR UPS
- Eaton 9PX Li-Ion UPS
- Eaton 9PX UPS
- Eaton 9SX Tower UPS
- Eaton DX RT UPS
- Eaton DX UPS
- Eaton Ellipse ECO UPS
- Eaton Marine UPS
- Eaton Power Module
- SANTAK UPS
- Schneider Galaxy 3L / EASY 3L UPS
- Schneider Galaxy VS UPS
- Schneider Galaxy VL UPS
- Vertiv UPS
Analysis of the main architecture and core component functions of a double-conversion online UPS
I. Core Architecture Components
1. Input filtering and rectification unit
Input filter:
Composed of inductors, capacitors and varistors, it filters out high-frequency noise, surges and voltage spikes (such as lightning strikes) in the power grid to protect downstream circuits.
Rectifier (AC/DC):
Uses IGBTs or thyristors to convert alternating current into direct current, providing a stable DC bus voltage (typically 380V DC) for inverters and battery charging.
2. Energy Storage and Battery Management
Battery packs:
Lead-acid batteries (mainstream) or lithium-ion batteries (emerging), providing backup power (typically 15-30 minutes). For example, 12V 100Ah batteries connected in series form a 384V system.
Battery Management System (BMS):
Monitors battery voltage, temperature, and internal resistance to achieve balanced charging, over-discharge protection, and life prediction (such as SOC/SOH estimation).
3. Inverter and Output Unit
Inverter (DC/AC):
Adopts full-bridge IGBT topology to convert DC power into pure sinusoidal AC power (220V/380V 50/60Hz), with total harmonic distortion (THD) <3%.
Static Switch (STS):
An electronic switch based on SCR or IGBT that seamlessly switches between mains power and inverter output within 0.5-4ms, ensuring zero load interruption.
4. Bypass and Redundancy Systems
Maintenance Bypass (Manual):
Manually switch to direct AC power supply during maintenance to isolate the internal circuitry of the UPS.
Automatic bypass:
When the inverter is overloaded or malfunctions, it automatically switches to mains power or a backup generator to ensure continuous power supply to critical loads.
II. Detailed Explanation of Key Component Functions
| Devices | Technical parameters | Functions and roles |
| IGBT module | Voltage 1200V-1700V, current 200-600A | The core switching devices of the rectifier/inverter determine the conversion efficiency (up to 97%). |
| DC bus capacitor | Electrolytic capacitor bank, capacitance 10,000-50,000μF | Smooth rectified output ripple, energy storage buffer (supports 5-10ms instantaneous power outage). |
| Digital Signal Processor | 32-bit DSP (such as TI TMS320F28335) | Real-time control of PWM waveform enables precise voltage/frequency adjustment (±1%). |
| Temperature sensor | NTC thermistor (accuracy ±0.5℃) | Monitor the temperature of critical components such as IGBTs and capacitors to trigger fan speed adjustment or over-temperature protection. |
| SNMP communication card | Supports Modbus/TCP and HTTP protocols | Remotely monitor UPS status (input voltage, load rate, battery capacity) and integrate it into the DCIM system. |
III. Comparison of Typical Topologies
| type | Architectural features | Conversion time | efficiency | Applicable Scenarios |
| Offline (VFD) | Direct mains power supply + battery backup | 2-10ms | 95-98% | Small IT devices |
| Online interactive | Bidirectional inverter with voltage regulation | 0-4ms | 90-95% | medium-sized server |
| Double conversion online | Full-time AC-DC-AC conversion | 0ms | 85-93% | Core Data Center (Tier III/IV) |
IV. Reliability Enhancement Design
Modular redundancy
uses N+X power modules in parallel (e.g., 6+1), and automatically disconnects when a single module fails, reducing MTTR (Mean Time To Repair) from 4 hours to 15 minutes.
The hot synchronization parallel operation technology
allows multiple UPS units to output phase synchronization (<1° error), achieving load sharing and seamless switching, with system availability reaching 99.9999% (annual downtime <32 seconds).
ECO mode dynamic switching
automatically switches to bypass mode when the power grid is stable, improving efficiency to 99% while maintaining 0ms switching capability .
V. Future Technological Evolution
Lithium-ion batteries: Use lithium iron phosphate batteries (6,000 cycle life), which are 60% smaller in size than lead-acid batteries and support fast charging (80% charge in 30 minutes).
AI predictive maintenance: By analyzing the growth trend of battery internal resistance through machine learning, it can provide early warning of failure risk up to 2 months in advance.
Photovoltaic-storage-DC-flexible (PDU): Integrates photovoltaics and DC microgrids to reduce AC/DC conversion losses, reducing PUE to below 1.1.
