New three-phase inverter reference design allows faster, more precise drive control
There is an increased use of robots in the era of automation to bring about higher productivity in manufacturing as well as lower costs. This requires robots to have faster response times as well as higher-precision positioning, which means improvements in motor-drive control.
High-precision in Motor Drive Control
Next-generation robots utilize three-phase ac motors to move its joints. Three-phase inverter power stages are the fundamental building blocks in industrial motor drive applications like robotics. The inverter converts a DC voltage into a variable frequency and power AC output to drive the motor.
These robots would be impossible to operate without precise motor-drive control during real-time operation. Here are some 3-phase inverter reference designs that make precise control possible:
Reinforced Isolated Phase Current Sense Reference Design with Small Delta-Sigma Modulators
This reinforced isolated phase-current-sense reference design allows designers to create a highly accurate, three-phase inverter subsystem using isolated IGBT gate drivers and isolated current/voltage sensors. It uses AMC1306E25 delta-sigma modulators that generate Manchester-encoded data/clock signals for the processor. In addition to developing a signal for each motor phase current, additional modulators are used to produce a temperature-monitoring signal as well as a signal to monitor the dc input bus. The feedback signals are processed by the TMS320F2837x Delfino 32-bit floating-point MCU. The MCU then generates the PWM for the ISO53xxx IGBT gate drivers.
Three-Phase High PWM Frequency GaN Inverter Reference Design for 200V AC Servo Drives
Another reference design solution is the TIDA-00915, a three-phase, high-frequency PWM frequency GaN inverter reference design for 200Vac servo drives. It features the LMG3410 600-V, 12-A GaN power module in place of the IGBT module. The GaN devices switch 5X faster than silicon FETs, while achieving efficiency levels greater than 98% at 100 kHz and greater than 99% at a 24 kHz PWM frequency.
With GaN, designers can optimize switch performance to reduce power loss in the motor and downsize the heat sink to save board space. Operating the inverter at 100 kHz significantly helps improve torque ripple when used with low-inductance motors. To view the news release, click here.
• Motor Integrated Drive
• Servo Drives