To reduce emissions, governments around the world, including the European Union and the United States, have introduced mandatory fuel economy standards for internal combustion engines. These initiatives require innovative advancements in technology, thereby driving the need for improved fuel efficiency, but this burdens design teams and can impact development cycle times.
The area of focus involved is the development of strategies to reduce the load on vehicle engines. According to statistics, only 15% of all fuel consumed by a car is used to drive the vehicle on the road, and the inefficiency of the engine and powertrain causes a lot of energy waste. Therefore, reducing the load allows the engine to work more efficiently, thus contributing to the reduction of fuel consumption. Our challenge is to maintain or improve the overall driving experience while delivering the same or higher performance. To achieve this goal, there is a growing need for vehicle electrification, which includes the use of electric motors in place of traditional belt drive systems. To this end, the application of electric motors in the global automotive market is growing at a compound annual growth rate (CAGR) of 4.7%. Specifically, the brushless DC motor (BLDC) market for automotive applications is expected to outpace the growth rate of other types of motors at twice the rate, with a CAGR of 6.3% from 2014 to 2019.
Improving these systems with electrical solutions creates new challenges for Tier 1 manufacturers, and these new innovations require increased headcount and development time. Designers are also seeking technical approaches to shorten development cycles while maintaining high performance for target applications. Therefore, the market share of BLDC motor control is gradually increasing. For example, automotive water pumps, which are often belt-driven, have transitioned to electric motors. This is a requirement for a start-stop system, which increases efficiency and reduces emissions. To keep the engine coolant circulating, replace the belt drive pump with an electric motor. Other applications that require conversion to BLDC motors due to engine start-stop systems include hydraulics and oil pumps, to name a few.
A new generation of motor driver ICs that integrate complex AC algorithms simplifies the engineering of BLDC motor control systems. Companies such as Allegro MicroSystems, LLC have developed proven algorithms for trapezoidal and sinusoidal control of sensored and sensorless BLDC motors, so engineers no longer have to write and verify software to meet tight deadlines.
Figure 1: Allegro’s proprietary algorithms reduce customer design and verification time.
In many of Allegro’s advanced motor drivers, the commutation algorithm has been integrated into the IC, and the easy-to-use software GUI transfers parameters to the on-chip EEPROM via USB for use by the on-chip algorithm. This enables engineers without software programming experience to design and verify motor systems, breaking the bottleneck of time-consuming tasks of software development and verification. This innovation also reduces the microcontroller workload, allowing developers to use low-power (low-cost) MCU devices. For some applications, the microcontroller can even be eliminated for further cost savings.
Allegro offers highly integrated sensorless BLDC drivers such as the A4960 and A4962, which integrate on-chip sensorless trapezoidal commutation algorithms and high power gate drivers to enhance external inverter bridge circuits. Highly integrated functions are often programmable to a microprocessor, allowing these devices to operate independently with integrated closed-loop speed or torque control. Comprehensive diagnostic feedback can be sent to the Electronic Control Unit (ECU) providing information on synchronization, overvoltage, undervoltage or MOSFET short-circuit conditions. Single-wire operation is possible by sending fault diagnostics through the PWM input.
The multi-function algorithm provides rich programming parameters, and only by modifying the parameters in the on-chip EEPROM, the engineering design can reuse hardware and other resources for different products. As a result, Allegro programmable motor drivers are easy to use and reusable for a wide variety of motors, loads and other applications. The highly integrated ICs can be used with Allegro programming tools to simplify workflow, shorten design cycles, and facilitate customer innovation. These solutions enable manufacturers to meet stringent fuel economy requirements through higher electrification, while delivering higher performance to end customers.
Figure 2: Allegro software can set parameters and load them directly into EEPROM, evaluating changes in real time.
Going forward, the trend towards autonomous vehicles will continue to drive increasing levels of vehicle electrification. Market analyst firm IHS Automotive expects sales of self-driving cars to approach 600,000 by 2025. In addition, IHS predicts that between 2025 and 2035, the compound annual growth rate (CAGR) of self-driving car sales will reach 43%, and by 2035, there will be nearly 21 million vehicles. This high growth will stimulate the continuous increase of motor control applications, and system integration will continue to drive designers to find innovative solutions. Self-driving cars need to integrate redundant systems to better assist consumers with safety concerns, cars will make more decisions for the driver, or with some new features, the driver can be completely removed from the decision-making process.
Companies such as Allegro MicroSystems, LLC are manufacturing and continually developing future products that meet ISO 26262 safety standards. The ISO 26262 standard defines requirements for Automotive Safety Integrity Levels (ASILs), which include the development process and design of safety-related electronic systems for on-road vehicles. These standards require IC component suppliers to integrate more functionality into existing solutions and require devices to be able to run diagnostics and update status communications. These innovative products provide on-chip monitoring and verification capabilities to help engineers simplify their designs and shorten design cycles.
As the automotive market continues to innovate to meet the need for improved performance and improved fuel economy, coupled with anticipated future developments in the autonomous vehicle market, electric motor systems will continue to play an increasing role as a better alternative to mechanical systems. Efficient solution. As a result, design engineers need to take advantage of advanced motors and related products that simplify the design process while providing customers with more value-added features to ultimately achieve cost-effective and competitive products. Allegro MicroSystems, LLC recognizes this need and provides industry-leading innovative products that meet the rigorous demands of the automotive market in the future.