Microchip Technology Inc. (Microchip) has introduced a new dsPIC digital signal controller (DSC) that offers expanded support for motor control applications. The dsPICDEM MCLV Development Board is a new low-voltage Brushless DC (BLDC) motor-control development platform supporting the dsPIC33F family of motor control DSCs. It offers a cost-effective method for evaluating and developing sensored or sensorless BLDC and permanent magnet synchronous motor (PMSM) control applications.
The board contains a three-phase inverter bridge circuit. This circuit drives a BLDC or PMSM motor using different control techniques, without requiring any additional hardware. The dsPICDEM MCLV board is capable of controlling motors rated up to 48V and 15 Amps, and supports multiple communication channels, such as USB, CAN, LIN and RS-232. It employs a processor-differentiated Plug-In Module (PIM) strategy to support a variety of dsPIC33F motor-control DSCs with different memory and pin configurations. A dsPIC33FJ32MC204 PIM (32 KB Flash and 44 pins) is included with the dsPICDEM MCLV Development Board.
Additionally, the company announced two new motor-control software solutions: one shows how Power Factor Correction (PFC) algorithms can be combined with sensorless motor-control algorithms on a single chip. The second software solution demonstrates how to run an AC Induction Motor (ACIM) faster than its rated speed for a class of applications, to lower cost, save space or reduce weight.
“Microchip is dedicated to providing the industry’s most robust product offering and associated infrastructure for motor control,” said Rich Hoefle, marketing manager for Microchip’s Digital Signal Controller Division. “As the need for improved reliability, better performance, lower cost and increased efficiency builds, dsPIC DSCs—along with their comprehensive suite of tools and libraries—fill an ever more important role.”
Power Factor Correction plus Sensorless Motor Control on a single chip:
The worldwide demand for improved power quality standards is driving the trend to add PFC to line-powered motor control applications. Power quality can be enhanced by implementing PFC, and efficient control of a motor can be realized using sensorless Field Oriented Control (FOC) techniques. Both can be achieved by integrating PFC and sensorless FOC algorithms on a single dsPIC DSC. Microchip’s Application Note 1208 describes the process of integrating these two complex functions in a PMSM application. This application note also lists the necessary hardware requirements, and provides the guidelines to optimize the development procedure.
Sensorless Field-Oriented Control of an AC Induction Motor using Field Weakening:
This algorithm provides high torque at low speed and high performance, with lower torque at extended speed. It is ideal for applications such as washing machines, automotive traction control, or any ACIM application that wishes to optimize torque per amp above the rated speed or constant torque region of an ACIM. The strategy is described in Microchip’s Application Note 1206, which provides source code for the dsPIC30F and dsPIC33F DSCs.
Enhancements to the MPLAB IDE:
To reduce motor-control development time, users can now tune motor parameters in real time, completely eliminating the stop motor/build/reprogram/run motor development cycle. The graphical Data Monitor and Control Interface (DMCI) in MPLAB IDE Version 8.15 have been enhanced to include a Real-Time Data Monitor (RTDM) function. DMCI enhanced with RTDM provides a graphical method to input and adjust motor parameters in real time and immediately see the effect, without halting the application. A serial USB or UART cable supports bi-directional information transfers between the host PC and the target dsPIC DSC. This tool is useful for modifying software parameters and visualizing historical data during debug sessions, so that the motor’s dynamic response can be analyzed.
“The motor-control market is diverse,” said Derek Carlson, vice president of Microchip Development Tools. “Our customers have a wide variety of motor performance requirements. At Microchip, we are committed to providing continuous enhancements to the MPLAB development environment to facilitate the variety of needs our customers encounter. We are pleased to add these new tools to enhance their success.”