How to Select Power Devices (IGBT / MOSFET) for Residential Storage and Inverters

Bottom line: power device selection looks at topology and voltage platform first, then losses and thermal. Use low-voltage MOSFETs in preference on the low-voltage battery side (48~60V); prefer IGBTs on the high-voltage side and in line-frequency topologies. During selection, work the numbers with three items — switching loss + conduction loss + thermal resistance — instead of looking only at the nominal voltage and current ratings.

Why Selection Goes Wrong So Easily

• Selecting by nominal values only: adequate voltage and current ratings ≠ usable in practice; switching loss and thermal resistance are what actually decide junction temperature.
• Selecting devices before the topology is fixed: different topologies (line-frequency / high-frequency machines, H6 / HERIC, etc.) have completely different device categories and drive requirements.
• Hesitating to try domestic alternatives: no confidence in measured data for domestic IGBTs / MOSFETs, when in fact one round of same-specification benchmarking gives the answer.
• Lead time and cost out of control: dependence on a single brand leads to passive shortage situations, with no second-source plan.

Selection Flow

flowchart LR
    A["Define topology and<br/>voltage platform"] --> B["Calculate current stress<br/>(RMS / peak)"]
    B --> C["Select device category<br/>MOSFET or IGBT"]
    C --> D["Calculate losses<br/>conduction + switching"]
    D --> E["Thermal check<br/>keep 20% junction-temp margin"]
    E --> F["Sample on board<br/>measure efficiency and temperature rise"]

Quick Device Category Comparison

Voltage platform / topology	Recommended device	Reason
Battery side 48~60V (low-voltage end of residential storage)	Low-voltage MOSFET (60~150V)	Low on-resistance, fast switching, high efficiency in synchronous rectification
High-voltage DC bus (300~500V)	IGBT discrete / high-voltage MOSFET	IGBT offers good voltage margin and better cost; high-voltage MOS is an option for high-frequency topologies
Line-frequency inverter	IGBT module / discrete	Low switching frequency, where the IGBT conduction-loss advantage is obvious
Hybrid-topology boost stage	IGBT or SiC, decided by frequency	Evaluate superjunction MOS / SiC when frequency is high and efficiency is sensitive

China Resources Micro Power Device Positioning

Product	Coverage	Typical application
IGBT discrete / module	Medium-low voltage to high voltage series	Inverters, welders, energy-storage conversion
MOSFET (including superjunction)	Low-voltage to high-voltage series	Residential-storage battery side, MPPT boost, motor drive
Diode / FRD	Companion fast recovery	Freewheeling and rectification paired with IGBTs

Specific specifications and the latest part numbers are subject to actual project discussion; Intek Technology can produce a selection comparison table directly from the customer topology parameters.

FAQ

Q1: How do I decide between MOSFET and IGBT?

Simplified judgment: below 200V withstand voltage with high switching frequency, choose MOSFET; above 600V with modest switching frequency (within 20kHz), IGBT gives better overall cost and reliability; the middle ground is decided by loss calculation and cost.

Q2: How risky is replacing imports with domestic IGBTs?

It comes down to three steps: parameter benchmarking → on-board measurement (efficiency, temperature rise, short-circuit withstand) → small-batch validation. Products from major domestic manufacturers such as China Resources Micro already have many mature cases in residential-storage and line-frequency applications, so the risk is controllable if you follow the process.

Q3: How much thermal margin is appropriate during selection?

As a general recommendation, junction temperature at full load should not exceed 80% of the rated value, leaving margin for high-temperature environments and surge conditions. Running junction temperature permanently at the ceiling significantly shortens lifetime.

Hqew Inquiry Channel

• Hqew store (online inquiry / real-time stock / ordering): Intek Technology Hqew store — search the specific China Resources Micro IGBT / MOSFET part number to inquire; samples and volume quotes supported.
• WeChat / Tel: 136-3264-8484 (Mr. Xiao); mention "China Resources Micro power device selection" for priority handling.

Contact Us

Intek Technology (Shenzhen Intek Technology Co., Ltd) is an authorized distributor of China Resources Micro (华润微) power devices (IGBT / MOSFET). For a selection comparison table based on your project topology, or to request China Resources Micro IGBT / MOSFET samples for testing, contact us. Selection review of protection devices (including AMSEMI foldback / snap-back TVS) can be raised at the same time.

Shenzhen Intek Technology Co., Ltd — electronic components distributor and system solutions provider Tel / WeChat: 136-3264-8484 Address: 4F, Building 2, Jingwei Center, No. 309 Pingan Avenue, Pinghu Street, Longgang District, Shenzhen, China Web: www.intek.vip