Industrial Inverter Solution

Selecting IGBT module voltage rating: (1) Input voltage: 380V AC systems choose 1200V modules, 220V AC systems choose 600V modules

(2) Safety margin: rated voltage should be at least 1.5x maximum circuit voltage

(3) Switching spikes: consider voltage spikes from parasitic inductance. Current rating selection: (1) Motor rated current: module rating should be 1.5-2x motor rated current

(2) Overload capability: consider current requirements during motor starting and overload

(3) Switching frequency: high frequency applications need larger current margin. Fuji 6MBI100VB-120-50 is suitable for 7.5-15kW inverters, 2MBI200VH-120-50 for 30-75kW inverters.

380V systems choose 1200V modules; module current should be 1.5-2x motor current; high frequency applications need larger margin.

Fuji 7th generation IGBT improvements over 6th generation: (1) Lower Vce(sat): 15-20% reduction in conduction losses

(2) Faster switching: turn-off time reduced by 30%

(3) Softness optimization: softer turn-off waveform reduces EMI

(4) SOA improvement: expanded safe operating area

(5) Chip optimization: thinner wafer and optimized carrier lifetime control

(6) Reliability improvement: advanced chip design and packaging technology

(7) Compatibility: drop-in replacement for 6th generation in many cases. 7th generation technology is especially suitable for new designs requiring highest efficiency and reliability.

New designs should prioritize 7th generation; existing 6th generation designs can be evaluated for upgrade based on efficiency requirements.

Braking unit design points: (1) Braking resistor selection: resistance R = Vdc / Ib, where Vdc is DC bus voltage, Ib is braking current

(2) Power calculation: braking power selected by duty cycle, typically 10-20% of peak power

(3) Braking unit configuration: for 380V systems, typical resistance is 50-100Ω, power 2-10kW

(4) Braking chopper: use IGBT or MOSFET as braking switch, switching frequency 1-5kHz

(5) Protection: overcurrent, overtemperature, and short-circuit protection

(6) Thermal design: braking resistors need forced air or water cooling

(7) Control strategy: automatic braking based on DC bus voltage. Fuji solutions support external braking units configurable by application needs.

Frequent braking applications choose high power braking resistors; occasional braking can use smaller power; thermal design must be considered.

EMI suppression measures for inverters: (1) Input filters: install three-phase EMI filters at power input to suppress common mode and differential mode interference

(2) Output filters: install dv/dt filters or sine wave filters at motor end

(3) Shielded cables: use shielded cables for motor connections with both ends grounded

(4) Grounding design: single point connection for power ground and control ground to avoid ground loops

(5) PCB layout: minimize power loops to reduce parasitic inductance

(6) Gate resistors: appropriately increase gate resistors to slow switching speed

(7) Metal enclosure: inverter enclosure properly grounded for shielding. EMI testing should follow CISPR 11 Class A (industrial) or Class B (residential) standards.

Industrial environments meet CISPR 11 Class A; residential environments meet Class B; professional EMC engineers can assist if needed.

Fuji IPM module advantages: (1) Simplified design: integrated drive and protection circuits reduce external components by 60%+

(2) Shorter development cycle: no need to design complex drive and protection circuits, development time reduced by 50%

(3) Higher reliability: factory-matched devices and optimized layout reduce failure risk

(4) Space saving: compact package design reduces PCB area

(5) Lower cost: although module price is higher, development and BOM costs are saved

(6) Complete protection: integrated overcurrent, short-circuit, undervoltage, and overtemperature protection

(7) Technical support: complete reference designs and technical documentation. Especially suitable for medium-low power, fast development applications. Fuji 7MBP50RA120 is suitable for 5.5-11kW inverters, 7MBP25RSB120 for low power appliance applications.

Standard topology, medium-low power, fast development needs choose IPM; special topology, ultra-high power choose discrete IGBT.

This solution supports multiple motor control algorithms: (1) V/f control: open-loop control, simple implementation, suitable for fans, pumps and general speed regulation

(2) Vector control (FOC): field-oriented control provides excellent dynamic performance and torque control for high-performance drives

(3) Direct Torque Control (DTC): fast response, low torque ripple, suitable for high-performance servo

(4) Sensorless vector control: No encoder is needed, reduces cost for general industrial

(5) PMSM control: supports SPM and IPM permanent magnet motor efficient control

(6) SynRM control: supports new high-efficiency synchronous reluctance motors. Fuji IGBT's fast switching characteristics (<200ns) ensure full algorithm performance.

Fans and pumps choose V/f control; general industrial drives choose vector control; high-performance servo choose DTC or direct torque control.