MB91580 32-bit microcontroller for HV/EV motor control

Fujitsu Semiconductor has launched the MB91580 series of 32-bit microcontrollers for HV/EV motor control and the MB86R11 system LSI for driver assistance display control. Let's take a look at the specific functions and features of the two devices and how they play a role in automobiles.

MB91580 drive motor control advantages

The MB91580 series is an energy-saving automotive drive motor control chip launched by Fujitsu Semiconductor to meet market demand. As a member of the FR family of high-performance 32-bit flash-embedded microcontrollers (MCUs), this series of products can be widely used in the drive motor control functions of electric vehicles and hybrid vehicles.

This series has a dedicated embedded resolver sensor interface that can pioneer the control of three-phase motors used in EVs and HVs, achieving the high torque response control process required for EV/HV drive motors to improve motor operation and reduce energy consumption.

In addition, built-in peripheral functions suitable for high torque response control processes can reduce system costs while achieving high-speed feedback control. The 12-bit A/D converter and R/D converter that detect current and motor position with high accuracy can detect electrical angles in synchronization with the A/D converter that detects three-phase current.

The dedicated floating point unit (FPU) integrated in the 160DMIPS high-performance CPU processes vector conversion and PID control operations using information generated by built-in peripheral functions. This feature helps improve motor operation and reduce energy consumption by achieving further fast feedback control. In addition, by suppressing the CPU load related to motor control, the system can be controlled instead of the power motor (DC/DC converter and battery management, etc.), which helps to reduce overall costs through system integration.

MB86R11 image display advantages

Figure 1: Fujitsu's proactive green contributions

There are three major innovations in hybrid and electric vehicles: The first is the innovation of electronic control units (ECUs) to improve the locomotive performance generated by hybrid and electric vehicle motors. The use of ECUs can improve the controllability of motors without changing the current hardware, including motors and inverters. The second innovation is to significantly reduce system costs through an overall optimization approach, including system reconfiguration. The third innovation is to improve the inverter module so that it can further meet power and energy-saving requirements, and use components that exceed the current IGBT loss characteristics to significantly improve energy efficiency.

To help customers achieve innovation, Fujitsu continues to develop products focusing on LSI and software, and provides various solutions in a timely manner. Figure 2 shows the three major innovations that are driving the further development of hybrid and electric vehicles.

Figure 2: Three major innovations in the development of hybrid and electric vehicles

ECU Innovation

Meeting the high torque response of hybrid and electric vehicles requires loop control to accurately detect motor operating conditions and calculate the control level of high-speed feedback information. The MB91580 series microcontroller with built-in R/D converter is a solution to meet ECU innovation. The focus is on achieving effective loop control. For example, the built-in 12-bit A/D converter and R/D converter of the MB91580 series can detect the current and position of the motor at high speed and accuracy, as shown in Figure 3. The electrical angle of the resolver is calculated by the R/D converter, which can lock the special function registers with the three-phase current detected by the A/D converter. The SIN (sine) and COS (cosine) values ​​of the electrical angle can also be automatically calculated in single-precision floating-point format (IEE754 standard). This will increase the calculation speed by 10% to 15% compared to the fixed-point method using traditional custom formats.

Figure 3: Motor control algorithm

Cost Innovation

One of the keys to the popularization of hybrid and electric vehicles is to reduce costs. This is possible through system integration. Figures 4 and 5 are block diagrams of innovations achieved through system integration of battery management ECU and DC-DC control ECU.

Figure 4: Consolidating system functions to reduce costs: BMS integration

Figure 5: System function integration to reduce cost: DC-DC integration

These integrations can be achieved by integrating ECU control with motor control in a microcontroller. As mentioned earlier, Fujitsu's MCU can suppress the CPU load rate through motor control, so it can perform battery management control and DC-DC control at the same time.

In terms of driving assistance, MB86R11 can realize the Passive Green function to help drivers experience the green life concept that challenges fuel consumption. Drivers can use the indicator function to check how to achieve Eco-Driving. MB86R11's image display function can freely switch display information according to driving scenarios and support safe driving, including vehicle boundary inspection using camera images, providing drivers with easy-to-use Eco-Driving assistance functions.