- From June 2016 [ Smart Car Journal ] " Change The World " section
Learn more about the technology trends and reference designs of the Smart Car Journal .
At present, the trend of automotive electronic functions is increasing, in response to increasingly stringent fuel efficiency regulations, and to meet consumer demand for energy, safety, comfort and convenience. Automobiles have evolved from mere mechanical products to complex mechatronic products, and the number of motors installed in automobiles continues to increase. It is predicted that by 2020, the number of motors in each luxury car will be as many as 120. Due to their various advantages, DC brushless (BLDC) motors are increasingly being integrated into automotive water pumps, oil pumps, fuel pumps, cooling fans, heating and ventilation air conditioning (HVAC), hybrid systems, seat fans and more. Achieve greater energy efficiency and performance.
Figure 1: Application of brushless DC motor in automobiles
Advantages of DC brushless motors
DC brushless motors eliminate the need for brushes and commutators, solve space-constrained system designs, and don't worry about general wear, sparks and noise, provide good control, and provide variable speed control for specific applications in the car. More importantly, DC brushless motors can improve fuel efficiency and save about 60% to 70% of energy consumption. When the brushless motor is used for electric power steering (EPS), the mileage is increased by 3~5%, and the electric water pump (EWP) and electric oil pump (EOP) are improved by about 3%, and the fuel pump is increased by about 1%. efficiency. For example, pumps and pumps are typically operated from engine power. If the engine is stopped, there is no power to the engine start-stop system. However, if the motor is used for pumps and pumps, these functions can be operated independently, regardless of whether the engine is started or stopped, thereby improving fuel economy.
Design considerations for DC brushless motors
If a brushless motor is used instead of a brushed motor, the work that had to be done mechanically by the commutator is now done electrically by a three-phase inverter. The inverter requires a gate driver, which is usually controlled by a microcontroller implementing complex software algorithms. This adds to the complexity of the system and is a major technical challenge for engineers. The intelligent DC brushless motor control and driver chip LV8907 from ON Semiconductor can solve this challenge. This solution eliminates the need for external motor position sensors or system microcontrollers, reduces PCB footprint, and comes with embedded control algorithms. It eliminates the need for self-write motor control algorithms, reduces system complexity, shortens development cycles, and speeds time-to-market.
Figure 2: LV8907 eliminates the need for microcontrollers and sensors in traditional solutions
Intelligent DC Brushless Motor Solution LV8907 Overview
The LV8907 utilizes sensorless drive logic for sensorless 120 or 150 degree control commutation with approximately sinusoidal operation to meet silent drive requirements. Configurable parameters for a range of motor and load combinations, one-time programmable (OTP) memory for parameter storage, custom solution, eliminating external components to perform various settings, enabling independent operation, integrated gate drivers, for Driving an external N-MOSFET, the charge pump drive provides 100% duty cycle and extended low voltage operation. The chip interacts with the outside world through the LIN interface, which provides configuration, real-time control and diagnostics. In automotive applications, it is required to operate at an ambient temperature (Ta) of 150 °C and a junction temperature (Tj) of 170 °C. The LV8907 withstands a working junction temperature of 175 °C, ensuring a harsh automotive environment. Reliability, fully compliant with the AEC-Q100 standard.
Figure 3: LV8907 block diagram
The LV8907 is highly integrated with MOSFET gate drivers, LIN transceivers, and low-dropout regulators (LDOs) to minimize footprint; no need to rely on position sensors, no software defects, fault detection and diagnostics, integrated week by week A series of protection features such as term flow, overcurrent protection, overvoltage/undervoltage protection, overtemperature protection, and stall protection. The state machine based solution uses OTP for parameterization, and no data damage caused by EMI/EMC problems. System reliability; the LV8907 requires no software and is easy to customize, reducing development time by up to 80% compared to microcontroller-based solutions, speeding time-to-market and saving bill of materials.
More integrated intelligent power module (IPM)
With the increasing cost of electronic circuits in the car, the reduction in size and weight, and the ever-increasing demands for higher reliability, smart power modules are better able to meet the trend. Such as ON Semiconductor's STK984 series, integrated BLDC LV8907 and multiple independent power MOSFETs, no need for boards, sensors and external microcontrollers, saving space, reducing weight, and reducing costs, used to drive automotive sliding doors, EPS Units, pumps, wipers, HVAC and cooling fans provide greater reliability.
Figure 4: Independent Sensorless Motor Control IPM
The STK984 series uses a unique Insulated Metal Substrate Technology (IMST) to integrate different components of semiconductor components and passive components and other components into a single module. The IMST structure covers the aluminum sheet by using an insulating layer, places the copper foil on the top layer, and etches it on the copper foil, so that the single-layer wiring pattern can be freely customized. Based on IMST's IPM, power transistors, control circuits and protection circuits that provide temperature detection can be mounted on the same board, thereby minimizing temperature detection errors and achieving high-precision temperature detection; due to aluminum sheets on metal substrates and A distributed capacitor between the copper foil passes through the insulating resin to effectively reduce noise; in addition, the IMST structure provides excellent heat dissipation.
For example, 3-phase brushless motor driver IPM STK984-090A-E/091A-E has built-in pre-driver IC, shunt resistor and charge pump circuit, integrated over-current, over-temperature, over-voltage / under-voltage protection features, can be used in automotive blowers Fans, cooling fans, pumps and sliding doors, etc.
Another example is the STK984-190-E integrating 7 MOSFETs into a single small package, using a direct-bond copper (DBC) substrate, no insulating liner, low thermal impedance, excellent heat dissipation and design flexibility, built-in reverse connection Battery protection for improved reliability, fully compliant with AEC-Q100 requirements, and motor power up to 300 W for 12 V systems. Compared with the discrete solution, STK984-190-E has 48.7%, 36.2%, 53.8% and 21.1% reduction in footprint, weight, component count and thermal resistance, respectively. It is ideal for applications such as automotive wipers, fans and pumps. Device.
to sum up
In order to cope with the trend of electronic functions of automobiles, there are more and more motors for vehicles, and they have developed from brushed DC to brushless DC. As the requirements for size and weight reduction, system cost reduction, and higher reliability increase, there is a need to continuously increase integration. ON Semiconductor offers a comprehensive brushless motor solution that includes discrete and integrated solutions such as the sensorless BLDC LV8907 and the more integrated IPM STK984 series, addressing software programming, space, cost and design time challenges. Energy efficiency, power density and system reliability are ideal for automotive applications such as pumps, oil pumps, fuel pumps, cooling fans, HVAC, wipers and sliding doors.
Poly Solar Panel Price,Half Cut Poly Solar Panel,Polycrystalline Pv Module,Solar Polycrystalline Panel
Wuxi Sunket New Energy Technology Co.,Ltd , https://www.sunketsolar.com