Inside every modern inverter and Uninterruptible Power Supply (UPS) lies a high-speed electronic switching semiconductor that converts direct current (DC) into alternating current (AC).
The two dominant semiconductor technologies used today are MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors) and IGBTs (Insulated-Gate Bipolar Transistors).
While MOSFETs are widely used in low-capacity consumer inverters, heavy-duty commercial and industrial UPS systems almost exclusively deploy IGBT technology.
In this engineering guide, we break down why IGBTs are the gold standard for high-capacity power backup systems.
What Is a MOSFET?
A MOSFET is a voltage-controlled semiconductor known for its ultra-fast switching speeds (often in hundreds of kilohertz).
- Strengths: High efficiency at low voltages (12V–24V) and low power levels (< 1,500 Watts).
- Weaknesses: As voltage and current increase, the internal resistance ($R_{DS(on)}$) rises exponentially, causing excessive heat dissipation and thermal runaway under heavy inductive surge loads.
What Is an IGBT?
An IGBT combines the best attributes of two electronic worlds: the high input impedance and simple gate drive of a MOSFET, combined with the high current-carrying and low saturation voltage capability of a Bipolar Junction Transistor (BJT).
- Strengths: Handles immense voltage (up to 1,200V+) and continuous high current with minimal thermal losses.
- Surge Resilience: Exceptionally robust against motor startup current spikes and short-circuit fault conditions.
Direct Comparison: MOSFET vs IGBT in UPS Design
| Engineering Parameter | MOSFET Inverter | IGBT Inverter (ESSMA Standard) |
|---|---|---|
| Optimal Voltage Range | Low DC Voltage (12V – 24V) | High DC Voltage (48V, 72V, 96V, 120V+) |
| Power Capacity Range | 500VA – 2,000VA (Small Home Units) | 3,000VA – 100KVA+ (Heavy Commercial) |
| Thermal Efficiency Under Load | Degrades rapidly under heavy current | Maintains ultra-low saturation voltage ($V_{CE(sat)}$) |
| Inrush Surge Tolerance | Sensitive to compressor startup surges | High instantaneous surge handling (300%) |
| Reliability & Lifespan | Moderate (prone to thermal stress) | Heavy-Duty Industrial Longevity (10+ Years) |
| Acoustic Noise | Prone to switching squeal under load | Whisper-quiet high-frequency switching |
Why ESSMA Employs IGBTs in Commercial UPS Systems
For models starting from 3KVA through 7.5KVA+, ESSMA UPS leverages high-grade fifth-generation IGBT power modules:
- Effortless Inverter AC & Motor Starts: 1.5-ton and 2-ton air conditioner compressors draw severe locked-rotor amperage on startup. ESSMA IGBT modules absorb these current peaks without tripping or voltage drop.
- Cooler Running Temperatures: Lower internal power dissipation means internal heatsinks stay up to 25°C cooler compared to parallel MOSFET arrays, significantly lengthening internal capacitor lifespan.
- True Double-Conversion Isolation: IGBTs allow high-speed PWM switching at pure 50Hz with total harmonic distortion (THD) under 2%.
Featured ESSMA IGBT Power Systems
- ESSMA 5KVA IGBT 72V Pure Sine Wave UPS — Best seller for clinics, offices, and luxury villas.
- ESSMA 7.5KVA / 120V Online Industrial UPS — Heavy commercial deployment with continuous double-conversion topology.
Discover why over 30 years of engineering in Bengaluru makes ESSMA the trusted name in high-durability IGBT power solutions.
