Electrical motors are essential for many applications. They allow physical motion, actuation, and control. Electric motors, due to their widespread use, are a primary target for energy conservation. Electric motors are estimated to consume almost half of all electricity produced globally. Electric motors’ inefficiency is a major concern for consumers, businesses and legislators. Many laws and regulations are in place around the world to set specific energy goals and improve motor efficiency. In order to achieve these goals, it is important that we continue to develop more reliable and efficient motors as well as control methods.

Driving Motor Efficiency

In order to increase the efficiency of motor drive systems, it is important to understand the different types and characteristics of motor technologies. The selection of the motor type and the components that make up its control system are crucial for an effective motor design. Currently, the brushed DC is the most common form of DC motor. However, as the market expands, the brushless DC motor (BLDC) is becoming more popular due to its efficiency, reliability and small size. The BLDC motor is superior to other motor types when it comes to optimizing size and efficiency in motor applications. BLDC motors are free of brushes and require less maintenance. They also provide better performance.

Permanent magnet motors are another main type of motor. They provide high coercive forces to allow high torque densities for motor control applications that require high torque. Three-phase motors (PMSM and PMSG), as well as single- and three-phase brushless DC, are used in many applications. These include servo motors and robotics. They can also be found in hand-held tools, appliances that run on batteries or lines, industrial prime movers, fans, pumps, and wind turbine generators. These devices are controlled by the information provided by the conveyor rotor. This is done by using the Hall effect or absolute encoders to measure the magnetic field of the rotor. However, many sensorless schemes are available to improve reliability and reduce costs.

In an induction motor, a three-phase voltage, applied directly to the stator, induces a voltage on the rotor conductors. Torque is produced by the interaction between rotor currents and stator flux. These machines are the least expensive because of their low maintenance and manufacturing requirements. They can be used in industrial applications or as generators in windmills. They can be easily started and regulated by variable frequency converters in open-loop systems without a rotor speed or position sensor. Below is a table that highlights the different motor types, as well as their main operational areas, which are associated with reliability, efficiency and performance compromises.

Table 2 describes the most common motor control techniques and applications. It is important to understand and define the motor application before selecting the best controller for analog or digital motor control solutions. Each application can use motor control techniques that require the adjustment of a single or multiple control loops. Precision and efficiency are determined by the method used to control voltage which determines speed, and current, which controls torque.

Table 2. Table 2.

Motor Control Techniques & Applications

Control Technique Applications

Speed up Rotate at a constant RPM or multiple RPMs Pumps, fans and compressors

Torque Keep force when changing direction Industrial machines, such as doors, conveyors and drive systems

Position You can move to the exact location Robotics, radar, satellite communications, drones

In order to increase the efficiency of motor drives, several factors must be considered, such as the motor construction, the system components and the drive method. Torque speed is an important motor characteristic because it determines the motor’s capacity to produce torque under different speeds. In addition, the inertia of the motor and its load affects its performance at different operating conditions. The electromagnetic inertia is defined by the same factors as the mechanical inertia, namely the resistance and the inductance.

Renesas Motor Controls: Accelerate your motor control design

The rapid growth in the motor control industry has been driven by the advancements in semiconductor electronics. Microcontrollers and microprocessors have played an important role. The electrical drive control has become more precise as MCUs are used to manage not only DC current and voltage but also three-phase voltages and currents.

Renesas provides comprehensive solutions to motor and inverter controls that support the entire development cycle. We provide every component necessary to create an effective and optimal motor control system. Four primary components make up our motor control solutions:

• Motor control devices: microcontrollers and ASSPs, as well as other critical analog components and power components
• Hardware Support ecosystem: Wide range of starter kits, solution kits and evaluation kits.
• Motor control algorithms : a library of software samples and application notes
• Motor Control Software Development Tools: A complete and easy-to-use software development tool that allows you to develop motor software simply by following the workflow.

Motor Control Devices

Renesas provides a wide range of ASSPs (application-specific standard products) for motor control based on the high-performance RX and RL78 These products can be used to satisfy a wide range of motor control requirements for embedded applications. Below are highlighted a few important characteristics:

• High Performance CPU: A single precision floating point unit operating between core frequencies of 32MHz to 200MHz, and a dedicated arithmetic module for trigonometric operations (s
• Enhanced Functionality: 32-bit general-purpose timers that can control up to three inverters simultaneously with 0-100% outputs. They also support PoE (power over
• Rich Digital Peripheral: Three 12-bit sample-and-hold ADCs, with a programmable gain amplifier (GPA) on the chip. The DAC unit can be used for motor protection and to interact with other components.
• Communication interfaces: Offers multiple communication methods such as USB 2.0 full-speed inc. Host controller or On-the-Go (OTG), ISO 11898-1 CAN interface, SCI multi-channel, SPI, and 400kbps SMBus, 2 These interfaces allow seamless communication with external systems and devices, including sensors, actuators, and HMIs.
• Encryption, Safety, and Protection Features Renesas’ MCUs are designed for motor control applications and include safety and protection features such as memory protection, cyclic-redundancy-check (CRC-Lite) calculator, and Trusted Secure IP.
• Scalability: MCUs are available in various models, with different performance levels, pin counts, and packages (48 to 144 LQFP pins, LGA, and BGA packages) but with the same concept for pin assignment. This scalability enables developers to select the best MCU for motor control applications while balancing space and cost concerns.