Author:
Ally Winning, European Editor, PSD
Date
03/05/2025
PDF
Cristian Ionescu-Catrina, product marketing manager. Power Integrations
Electrical motors use up a large amount of the electricity that we generate. Making them perform more efficiently, and therefore reducing that demand, would go a great way to helping with our transition to a greener energy mix. Brushless DC (BLDC) motors are some of the most popular types of electric motor due to their high power to weight/size ratio and efficient operation. The design also offers other benefits, such as high reliability, ability to operate at high speed constantly and operation over the whole speed range. However, there is a downside in that to gain these efficiency benefits requires complex control.
Like many other motor designs, the BLDC motor has a stator with at least three electromagnetic poles. These poles are energized in sequence to create a revolving magnetic field. There are permanent magnets embedded in the rotor. The two magnetic fields interact, and the rotor spins as the pole on the rotor tries to catch the moving pole on the stator that has the opposite polarity. The electromagnets on the stator are energized by electronic switches, mainly MOSFETs, which are controlled by the MOSFET driver, which is in turn, controlled by a microcontroller that takes inputs from a variety of sources to calculate the correct signals. The microcontroller normally runs very complex software to make the correct decisions.
Power Integrations has been operating in the motor control market for a number of years with its BridgeSwitch motor-driver IC family, and companion MotorXpert software suite for the control and configuration of high-efficiency, single- and three-phase BLDC inverters. The company has recently released version 3.0 of the software. The new software release is intended to simplify the implementation of motor designs as well as adding new functionality.
Cristian Ionescu-Catrina, product marketing manager at Power Integrations explained, “the previous version of the software was complex. For example, to program the rotor position needed the manipulation of six different parameters. As you can imagine, this is a balancing act, as one parameter can can have effects on on the functionality of others. It was difficult for people without extensive knowledge to play with all of the six at the same time. The new version extends the capability of the tool by adding a default tuning option, which only has two parameters, which is sufficient for engineers without the advanced skills or time to set all of the parameters needed. It lets the engineer choose between expert mode and default mode for tuning.”
A second major addition to the MotorXpert software is to implement shuntless and sensorless technology for field-oriented control (FOC). Designers are being pushed to bring smaller and lighter designs to market. Cutting down the number of components helps with that, decreases the BoM cost and also brings less risk of a failure occurring. Getting rid of the sensor that detects the rotor position also helps with performance as it can often degrade over time. Other new features added to MotorXpert 3.0 are support for advanced modulation schemes and unconditional startup under any load condition. There has also been significant improvements to the host user interface and debugging tools.
One of the benefits of MotoXpert 3.0 software is that it can be used to set up automatic responses for the driver chip, freeing up the microcontroller for other tasks. Ionescu-Catrina said, “we wanted to add more application layer flexibility, and more versatility to the tool. In a system, other parts of the system interact with the motor so that there are events coming from the motor system. The software includes the ability to program the response of the system based on those events coming from the motor and the inverter. When an over current event happens, do this, and when an over voltage protection comes, do that. That means you don’t have to spend time coding these features. It's already in there. And just needs configured.”
MotorXpert suite is MCU-agnostic and includes a comprehensive porting guide to simplify deployment with a wide range of MCUs. It is implemented in common C language to MISRA standards.
The MotorXpert v3.0 host-side application includes a GUI with Power Integrations’ digital oscilloscope visualization tool to help design and configure parameters and operation and simplify debugging. Parameter tool tips and a tuning assistant improve the development process, and the intuitive parameter list provides easy motor tuning. The new version also features both V/F and I/F control, which permits motor startup in any load condition. A selectable two-phase modulation scheme allows developers to trade off temperature of the inverter vs torque ripple which is beneficial in applications such as hot water circulation pumps, reducing heatsinking requirements and enclosure cost. Single- and three-phase code libraries with sensorless support are included along with reference designs, and other tools such as a power supply design and analysis tool.
MotorXpert v3.0 is available at no cost with an end-user license agreement.
