Electric vehicle resource network news:

On June 1-2, the new energy vehicle industry event hosted by the electric vehicle resource network-"2017 The Third China New Energy Vehicle Operators and Vehicle Enterprises Matching Procurement Exchange Conference and New Energy Vehicle Complete Vehicle Enterprises and Parts Enterprises The "Technology Exchange Forum" was grandly opened at the Chongqing Yuelai International Conference Center. Hundreds of domestic new energy vehicle companies and industry experts conducted in-depth discussions on many issues under the new situation in 2017 to find good solutions for the pain points of the industry. The electric vehicle resource network reported this conference throughout.

On the afternoon of June 1, the theme of the conference was "Reliability, Safety, and Cost-Reducing Technology Innovation Routes for Key Components", and Yu Shuhuai, Chairman of Suzhou Oyikes Automotive Electronics Co., Ltd., titled "Typical Hybrid Vehicle Power System and "The introduction of its electronic control program".

Yu Shuhuai: Introduction of typical hybrid electric vehicle power system and its electric control scheme

Yu Shuhuai, Chairman of Suzhou Auto Electronics Co., Ltd.

The main contents of the speech of Chairman Shuhuai organized by the electric vehicle resource network are as follows:

In May 2016, the Ministry of Industry and Information Technology issued a detailed interpretation of "Made in China 2025", and clarified that the main technical routes of hybrid new energy vehicles are plug-in hybrid (PHEV) and extended range. In November 2016, the National Automotive Industry Technology Roadmap was released. In addition to new energy vehicles, it also put forward requirements for the development of hybrid electric vehicles: the market share of new energy vehicles + hybrid electric vehicles reached 35%. Yu Shuhuai mainly introduced three electronic control technology solutions: "Extended Range Electric Vehicle, P1+P3 Plug-in Hybrid Electric Vehicle (PHEV), and 48 Volt Weak Hybrid Electric Vehicle".

The extended-range electric vehicle electronic control technology program: including the brief structure, extended-range engine, CAN network architecture, main control methods, main control strategies, development and calibration procedures, development difficulties, etc.

P1+P3 plug-in hybrid electric vehicle (PHEV) electric control technology program: including brief structure, power system composition, engine program, main working mode, engine EMS new control strategy, vehicle calibration work, etc.

48-volt weak hybrid vehicle electronic control technology solution: including advantages, system structure, fuel saving potential and actual vehicle test results.

First, the extended-range electric vehicle electronic control technology program

The extended-range electric vehicle is a purely electric-driven vehicle and a plug-in electric vehicle. The main function of the range extender is to charge the battery or directly provide power to the drive motor, extend the driving range of the vehicle, and heat the battery by charging the battery in low temperature areas; the secondary function is to drive the air conditioner compressor to work and provide warm air.

The engine needs to be specially designed for the range extender, such as: no flywheel and no starter, the crankshaft is directly connected to the rotor shaft of the generator, reducing the axial size; the maximum speed is 4000 rpm, which maximizes light weight and lower fuel consumption; The wheel train is specially designed without the special design of generator and air-conditioning compressor; the rear end of the cylinder is rigidly connected to the generator; other: balance shaft, exhaust passage, oil pan, forced water cooling of exhaust, etc.

In order to improve adaptability, a separate network is planned inside the range extender to control the working state of the range extender. Because it involves a range extender, especially for passenger cars, engine emissions need to be considered. The development cycle of the extended-range electric vehicle electronic control system will be relatively long, which generally takes one and a half to two years. It takes about half a year to develop the principle of the product and the basic performance of the prototype. After the acceptance is passed, a durability test of 160,000 kilometers is required. The announcement test process takes about 10 to 12 months because the engine is also involved Calibrations for emissions, three highs, and OBD are required. The development and calibration process of plug-in hybrid electric control system is basically similar, so the development of a set of electric control system needs to be planned for a long time in advance.

The development of the range extender electronic control system has the following difficulties: (1) NVH optimization: vibration and noise; (2) starting control: starting torque, reverse control, starting control logic, secondary flooding, etc.; (3) row Temperature and discharge control: Excessive discharge temperature, durable discharge, etc.

2. PHEV (P1+P3) power system solution

P1+P3 scheme, the low and medium speeds are driven by pure electric, and the engine directly drives the vehicle at high speeds; it is suitable for models with high-speed driving conditions such as A-level models and SUVs, and the overall fuel consumption is about 2L/100km. The engine, generator/starter, and motor form a power unit through a power coupling device.

The Atkinson cycle engine is most suitable for PHEV. The engine dedicated to PHEV uses the Atkinson cycle with a minimum specific fuel consumption of 230g/kWh. For ordinary engines, the minimum specific fuel consumption is 250g/kWh. With the Atkinson cycle, the fuel consumption is lower and the minimum specific fuel consumption is <230g/kWh. In the NEDC cycle of PHEV, 90% of the operating points are located in the high efficiency zone (<250g/kWh).

The calibration workload of the EMS system in PHEV is greater. (1) A special Atkinson cycle engine is used, the software needs to be specially modified, and the calibration workload is larger; (2) The starter is cancelled, the ISG motor is used to start the drive, and the starting process control logic needs to be added; (3) The ignition key needs to add automatic start-stop control logic; (4) The electronic accelerator pedal is not connected to the ECU, but directly to the HCU, so the ECU needs to add PHEV-specific torque control logic; (5) According to the vehicle CAN bus architecture and Definition, need to add special CAN communication content; (6) need to add special warm-up control logic; (7) need to add ignition control logic during shutdown; (8) need to add control logic to prevent reverse. Yu Shuhuai said that the calibration workload of the EMS system in PHEV has increased by about 50% compared with traditional vehicles.

Three, 48 volt weak mixing system

The 48-volt weak mixing system is gradually being accepted by the market. The use of gasoline direct injection engine and conventional gearbox technology has been unable to meet the fourth stage fuel consumption requirements. The 48V BSG system is relatively mixed with extended range and plug-in. It has a simple structure, low cost, and a small amount of system modification.

Under ideal conditions, the 48-volt weakly mixed system can achieve about 10%-15% fuel saving effect. The domestic technology is relatively mature, with years of technology accumulation, the BSG weak mixed system control strategy is mature, and has the conditions for mass production; the use of AC motors, split motor controllers, domestic batteries, the supplier is rich in resources, the technology is mature, all are mass-produced products .

In fact, the 48-volt weak mixing system is mainly for reducing costs. It cannot be solved by the traditional method. The cost increase after mass production is about 3000-3500 yuan. Weak mixing control strategy is integrated into the engine ECU, no additional electronic control units are needed; AC motors are used, the technology is mature and the cost is the lowest, and the annual output is more than one million; it is recommended to use split generators and motor controllers for after-sales maintenance The service cost is the lowest. The 48-volt weak hybrid system is the only hybrid system suitable for MT. (Source: Electric Vehicle Resources Network Yue Shaoxue)