The operation of motorized systems alone accounts for approximately 50% of global electricity consumption and 60-70% usage in the industrial sectors of developed nations. Therefore, reducing energy consumption in these systems is crucial for environmental longevity. Our broad semiconductor portfolio, development tools eco-system and reference designs facilitate the creation of an energy efficient motor control system that eases the demands on power grids to foster a sustainable future.
Boosting Energy Efficiency in Electric Motor Applications
Electric motors are an integral part of a variety of systems including pumps, conveyors, compressors, fans, robotic systems, appliances, material handling systems and CNC machines. These systems are essential for the operation of industrial processes, harvesting resources using smart agriculture, e-mobility and the operation of HVAC units in both residential and commercial settings. Enhancing the energy efficiency of motion control in these applications is crucial, as it can lead to a substantial decrease in greenhouse gas emissions and contribute to a more favorable environmental footprint.
In addition to the proper sizing and selection of the motor type, systems developers consider the following factors when designing real-time, embedded motor control systems exhibiting low power losses for longer battery life and higher longevity:
Optimal voltage and current delivery to a motor
Lower in-rush and motor starting currents
Thermal management optimization
Cost, Size and Noise Reduction
High Power Density
Functional safety and security
Most of these design objectives can be achieved at the system level through selection of an appropriate low-voltage microcontroller (MCU) or microprocessor capable of expeditious mathematical computation and digital signal processing required for deploying real-time control, with highly integrated peripherals for execution of multiple functions using a single device. Furthermore, it is critical to utilize DC/DC converters throughout the system that exhibit adequate energy efficiency at varying load conditions, as well as measurement and signal conditioning integrated circuits (ICs) with wide bandwidth and fast sampling conversion rates to facilitate quick response to motor rotor position and angular speed and torque requirement changes. In essence, the hardware solutions that constitute the motor control system should dynamically adjust pulse width modulation (PWM) signal outputs from the microcontroller or microprocessor to the gate drivers in the power stage to regulate voltage and current delivery to the motor. The voltage and current delivered to the motor depend on the torque and speed demands. AC Induction and Permanent Magnet Synchronous Motor (PMSM) type motors commonly use Variable Frequency Drives (VFD) to vary the frequency and voltage to manipulate the speed and torque of the motor so it can complete its operation as efficiently as possible. We provide motor control software libraries that feature functional code blocks for implementing Field Oriented Control (FOC), a vector control method for variable frequency drives, using either dsPIC® Digital Signal Controllers (DSCs) or 32-Bit MCUs. In comparison to sinusoidal and trapezoidal control methods, FOC algorithms for motor control offer numerous benefits, particularly in high-performance applications that demand precise torque control and low operational noise. Most notably, FOC algorithms contribute to significantly improving energy efficiency. For example, FOC control allows for independent control of the magnetic flux and torque of the motor allowing operation at the most efficient point depending on the load condition applied. To augment the implementation of FOC control, we offer application-specific algorithms tailored to sustainable design practices:
Flux Weakening: Limit voltage demand on the motor at higher speeds
Initial Position Detection (IPD): Start motor motion without retrograde motion
Soft Stop: Limit DC voltage spikes by controlled reduction in motor speed
Stall Detection: React to motor stalls to limit motor overcurrent
Windmilling: Detect speed and position of a free moving motor
Torque Compensation: Detect and reduce motor vibrations
To enable the construction of a complete motor control solution encompassing the controller, the interactive block diagram on the Energy-Efficient Motor Control Systems page on the Microchip Sustainability site (Figure 1) provides a system designer with guidance on using our broad product portfolio to build a sustainable system connected to the power grid, a renewable energy source or an energy storage system (e.g. lithium-ion battery).
Key Microchip Technology Device Solutions for Sustainable Motor Control:
FPGAs, 8/16/32-Bit MCUs and dsPIC® Digital Signal Controllers
Silicon Carbide, Power MOSFETs, IGBTs Power Discretes and Modules
Power Management: LDO, Switching Regulators
Figure 1: Energy-Efficient Motor Control System Interactive Block Diagram
We offer an ecosystem of development tools, reference designs, software libraries for BLDC, PMSM, ACIM and stepper motors running sensor based or sensor-less control algorithms and a broad portfolio of low power products to design embedded, real-time motor control systems.
Jay Nagle, Aug 15, 2024
Tags/Keywords: Automotive and Transportation, Sustainability
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