RL78 Microcontrollers Help Reduce System Cost and Size

We are surrounded by electrical appliances using motors. In recent years, the variety and numbers have continued to increase, and the controls that are required have grown more diverse. After the 78K and R8C Family, the RL78 microcontrollers (MCUs) have been used in a wide range of applications that use motors. Among the broad device lineup, the RL78/G1F inherited RL78/G14 features and is highly suitable for motor control solutions. On top of the devices to realize motor control, Renesas also provides solutions to aid the development of motor control solutions.

A Variety of Capabilities

The RL78 microcontroller can be used to implement a variety of motor control functions. Here are some application examples and accomplishments.

High-Speed Rotation

High speed rotation control is required for cordless vacuum cleaners, drones, and other small motor applications. Experiments using the RL78/G1F have seen confirmed rotations of more than 500 krpm. We are preparing high-speed rotation solutions to assist in the development of cordless vacuum cleaners.

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High-speed rotation of 50 krpm with a vacuum cleaner motor

High-speed rotation of 50 krpm with a vacuum cleaner motor

Position Estimation at Stop

In general, it is difficult to detect the position of a motor with sensorless control when it is stopped, because detection relies on the induced voltage generated by the rotor. With the RL78/G1F, you can use the polarity of the motor to detect the position when stopped.

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RL78/G1F sensorless BLDC motor initial rotor position detection demo

RL78/G1F sensorless BLDC motor initial rotor position detection demo

Refrigerator

The automatic adjustment software for a refrigerator compressor using the RL78/G1F identifies the motor parameters and control gain, and the compressor can be driven instantly with 1-shunt sensorless vector control.

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Refrigerator motor

Refrigerator


High-Speed Rotation Solution

Features

  • High-speed rotation at 20 krpm (mechanical angle) or higher can be realized
  • The motor settings can be changed (input voltage: 12V to 50V)
  • The control parameters can be easily adjusted
  • The Renesas Motor Workbench development support tool can be used to adjust these settings easily
Components
Inverter GDB01
Communication board for tools USB-Serial converter board
Control software Sensorless rectangular wave control
RL78/G1F Sensorless 120-degree conducting control for permanent magnetic synchronous motor (high-speed rotation) - Sample Code (ZIP)
Development Support Tool Renesas Motor Workbench
Documents Schematic, BOM, application note
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Conceptual image showing use of the high-speed rotation solution

Conceptual image


Evaluation Environment

1. Starter Kits and Inverters for Evaluation

Product Name Product Number Vendor Remarks
24V Motor Control Evaluation System (RSSK) RTK0EM0006S01212BJ Renesas Electronics DC24V input 5A peak, motor included
Trial Series Inverter Unit (High Voltage) T1001, T1102, T1003 Desk Top Laboratories AC110V/230V input 300VA to 4KVA
Trial Series Inverter Unit (Low Voltage) T2001, T2003, T2005, T2006, T2007 Desk Top Laboratories DC24V/48V input 5A peak to 100A peak
Brushless Motor Starter Kit BLM_EV6 Hokuto Electronic DC 7.2V input 2A peak, motor included
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24V Motor Control Evaluation System for RX23T

24V Motor Control Evaluation System (RSSK)

  • Easily evaluate motor control using an MCU
  • Sample software such as vector control and rectangular wave control is available
  • Renesas Motor Workbench development support tool is provided
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Trial Series Inverter Unit

Trial Series Inverter Unit

  • Wide range from low to high voltage
  • Useful for evaluation and development
  • The ICS++ Development Support Tool is available

CPU Cards

Optional boards for the Evaluation System for BLDC Motor and 24V Motor Control Evaluation System for RX23T. You can purchase additional CPU cards and swap them out to allow motor control with various microcontrollers.

MCU Product Number Vendor Inverter Remarks
RL78/G14 RTK0EML130C06000BJ Renesas Electronics RSSK, Trial Series Inverter Unit 64-pin
RL78/G14 T5101 Desk Top Laboratories RSSK, Trial Series Inverter Unit 64-pin
RL78/G14 T5105 Desk Top Laboratories RSSK, Trial Series Inverter Unit 32-pin
RL78/G1F RTK0EML240C03000BJ Renesas Electronics RSSK, Trial Series Inverter Unit 64-pin
RL78/G1F T5103 Desk Top Laboratories RSSK, Trial Series Inverter Unit 64-pin
RL78/G1F HSBRL78G1F-64 Hokuto Electronic Brushless Motor Starter Kit 64-pin
RL78/G1G T5104 Desk Top Laboratories RSSK, Trial Series Inverter Unit 32-pin
RL78/G1M T5108 Desk Top Laboratories RSSK, Trial Series Inverter Unit 20-pin

2. GDB01 Inverter for Evaluation

Features

  • Wide voltage range and high current (input voltage of 12 to 50V, peak current of 30A)
  • Various types of BLDC motor control are possible (3-shunt, 1-shunt, encoder, Hall, sensorless, FOC, trapezoidal)
  • Renesas Motor Workbench with a tool communication board (or ICS) is provided

Specifications

  • Input Voltage: DC 12 to 50V
  • Input Current Limit: 30[A]@ shunt 10mΩ
  • Current Detection Method: 3-shunt and 1-shunt (DC Link)
  • Target Motor: BLDC Motor
  • Dead Time: more than 1µs
  • Heat dissipation: Natural air cooling with heat sink
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GDB01 inverter for evaluation

Block Diagram

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RL78/G1F Motor Solution Block Diagram

 

 

Block Products
MCU RL78/G1F
Half Bridge Driver HIP2101
MOSFET RJK0703DPP-A0
Op-Amp READ2302G

Documents

3. MCU Simulator Online

Initial evaluation of the RL78 can easily be started online.

The MCU Simulator Online can be used for the following:

  • Checking the terminal output for register settings
  • Estimating processing time
  • Debugging variable watch functions in software
Simulation scope
MCU RL78/G1F
Control method 120-degree conducting control
Inverter RSSK

MCU Simulator Online

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Easily conduct motor driving simulations without motor hardware using MCU Simulator Online

Easily conduct motor driving simulations without motor hardware

Sample Software and Application Notes

Control method  
120-degree conducting control (Hall sensor & sensorless) RL78/G1F 120-degree conducting control of permanent magnetic synchronous motor (Implementation) - Sample Code (ZIP)
RL78/G1M 120-degree conducting control of permanent magnetic synchronous motor (Implementation) - Sample Code (ZIP)
120-degree conducting control with initial position detection function (sensorless) RL78/G1F Sensorless speed control of 120-degree conducting controlled permanent magnetic synchronous motor with detection of initial position (Implementation) - Sample Code (ZIP | English, 日本語)
Vector control (sensorless) 3-shunt current detection RL78/G1F Sensorless vector control for permanent magnetic synchronous motor - Sample Code (ZIP)
Vector control (sensorless) 1-shunt current detection RL78/G1F*

*Please contact a sales/distributor location to obtain more information.


RL78 Motor Control MCU Lineup

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RL78 Motor Control MCU Lineup

For details on each solution, please contact a sales/distributor location.