EV battery swapping-technical scheme and characteristics analysis
Table of Contents
Among the many factors that affect the development of new energy vehicles, charging and changing power are two simultaneous exploration technology routes. The limitation of charging lies in the charging time, battery life, etc; EV battery swapping also has limitations-maturity, standardization and profitability of power replacement technology (investment return of ev battery swapping and backup battery).
However, by contrast, ev battery swapping can not only meet the requirements of operating mileage, but also ensure the long life of the battery, which is more conducive to recycling. This paper will analyze a variety of ev battery swapping technology solutions.
Evolution of ev battery swapping technology scheme
The attempt of ev battery swapping in new energy vehicles can be traced back to the Israeli BetterPlace (BP) in 2003. BP cooperated with Renault in France, and Renault developed the electric vehicle type FluenceEV, which uses chassis power change for power change. In the general environment of electric vehicle development at that time, the application scale of electric vehicles was very limited.
In addition, the high cost of battery technology, ev battery swapping technology and power exchange station construction made the technical scheme uncompetitive, and the project was terminated. China Southern Power Grid has also introduced the scheme of BP and has demonstrated its operation in Guangzhou and other places.
In 2009, China promoted the development of new energy vehicles. Since 2011, the State Grid has been the main force to promote the power swap mode. First, the State Grid (Hangzhou) Integrated Energy Services introduced semi-automatic battery switching in the standard box. In 2013, Xinxiang County Power Industry Bureau led the joint efforts of car companies and taxi companies to promote the taxi operation of chassis replacement, but failed to promote it.
In 2013, with the promotion of policy and technology development, China’s new energy development accelerated. Attempts to replace power are also expanding. State Grid power exchange project personnel set up an independent Bertan company to promote side wall power exchange and chassis power exchange in Hangzhou, Xi’an and other places.
Zhejiang Xinshikong’s side wall power exchange mode has made relative progress in technical verification through large-scale demonstration and operation in ev battery swapping.
In 2016, Aulton joined the power swapping operation, cooperated with other automobile companies to promote chassis power exchange, and successively carried out large-scale power exchange operations in Guangzhou, Xiamen and Beijing, China. Vehicle enterprises are trying on the technical route of ev battery swapping.
Introduction to the technical scheme of ev battery swapping
The ev battery swapping of trunk
The State Grid (Hangzhou) Integrated Energy Services battery swapping station takes 20 standard battery boxes as a group, and each box has about 5 kWh of electricity, which is loaded into the battery transfer box for centralized charging and power exchange.
The Hangzhou tram replacement model is mainly used for taxis and official vehicles. There are two types of ev battery swapping equipment: mechanical platform and movable forklift platform, which are fixed beside the car exchange position.
The battery box in the boot of the electric vehicle is pulled out and pushed in manually. This scheme of ev battery swapping is basically an initial attempt to change power in China.
Chassis and side wall ev battery swapping
The battery box of the pure electric vehicle is arranged at the bottom of the car, with two boxes of batteries on the left and two boxes on the right. After the battery is controlled to rise and fall in the car, the battery is taken out from the side by the robot.
● The ev battery swapping of side wall
The feature of this power exchange technical scheme is that the power exchange port of the battery is arranged on the side wall, the battery cabin door is opened by controlling, and then the battery is taken out and installed on the side of the manipulator. In this scheme, the battery is arranged on the chassis, which makes the body height higher and affects the vehicle performance.
● Chassis power change
The chassis power replacement scheme of ev battery swapping can be subdivided into two types: the standard battery box represented by State Grid Shanghai Electric Bus and the special-shaped battery pack represented by BP.
BP’s plan is that after the vehicle is in place, the vehicle will remain still, the mechanism under the ground will horizontally transmit the battery, lift the battery up and down to install the battery, and the servo motor will tighten and loosen the battery locking mechanism to complete the entire ev battery swapping action.
The “tower type” special-shaped battery for chassis replacement is arranged on the chassis between the rear seats and the boot. This scheme of ev battery swapping has the least change to the chassis frame, but still affects the rear row space and trunk volume.
Technical proposal for chassis power replacement
Among various power replacement technical solutions in ev battery swapping, chassis power replacement has been more recognized. At present, the most widely used structure is the flat structure arranged on the chassis, which basically does not occupy the riding space, boot space and vehicle height. The battery pack is fixed on the power exchange frame, which is adapted to the existing body structure and installed on the body floor.
During the ev battery swapping, the battery pack and the power change frame shall be disassembled as a whole. The battery module, the lower box assembly, the power distribution box, the battery management system and the upper box cover form a battery pack (PACK), which is then installed on the replacement motor assembly to form an integral replacement battery pack.
At present, the difference of chassis ev battery swapping technology mainly lies in the different locking methods. In the chassis ev battery swapping technical scheme, the replacement of the quick change battery pack is divided into two steps: lifting and locking. The lifting movement is vertical; The locking scheme is divided into rotary tightening/loosening and forward and backward translation.
Lifting and rotating tightening
BP and State Grid have adopted this scheme of ev battery swapping. The main action of the ev battery swapping is to lift the battery pack in place by the manipulator, and then rotate the locking mechanism, which is combined with the positioning on the chassis, clamped, tightened and locked. The locking points have obvious positioning grooves. Technically, the locking is more reliable, and the locking can be accurate.
Lifting and forward and backward translation
The main action of ev battery swapping: lift the battery pack in place by the manipulator, and then move the battery pack as a whole, relying on the seam, detent and lock on the chassis. In practical application, this scheme has the problems that locking is not easy to be in place and locking is loose.
Comparison of two technical solutions
● Weight
The rotary locking scheme of ev battery swapping has lighter weight, smaller locking range, better adaptability to different vehicle sizes, and lower requirements for chassis frame space.
● The ev battery swapping connector
The floating range of the exchange connector of the rotary locking scheme is larger, so the environmental adaptability is better, the weight is light, the matching size requirements are lower, and the battery can be expanded to adapt to different cooling modes.
● Service life
In terms of life, the life of key components of the two schemes of ev battery swapping is similar. However, in terms of comprehensive cost, the rotary locking scheme is better. From the comparison of the above three aspects, the rotary locking scheme of ev battery swapping has more advantages, and has the most demonstration applications at present.
Summary
In addition to technical feasibility, the large-scale sustainable application of ev battery swapping mode also needs to further verify its economy through operation, as well as the generalization of different battery packs for different models.
It is believed that with the development of battery and other technologies and the rapid decline of costs, the ev battery swapping mode (power replacement technology scheme) will gradually occupy a specific market and promote the accelerated development of new energy vehicles.
EV battery swapping-technical scheme and characteristics analysis
Table of Contents
Among the many factors that affect the development of new energy vehicles, charging and changing power are two simultaneous exploration technology routes. The limitation of charging lies in the charging time, battery life, etc; EV battery swapping also has limitations-maturity, standardization and profitability of power replacement technology (investment return of ev battery swapping and backup battery).
However, by contrast, ev battery swapping can not only meet the requirements of operating mileage, but also ensure the long life of the battery, which is more conducive to recycling. This paper will analyze a variety of ev battery swapping technology solutions.
Evolution of ev battery swapping technology scheme
The attempt of ev battery swapping in new energy vehicles can be traced back to the Israeli BetterPlace (BP) in 2003. BP cooperated with Renault in France, and Renault developed the electric vehicle type FluenceEV, which uses chassis power change for power change. In the general environment of electric vehicle development at that time, the application scale of electric vehicles was very limited.
In addition, the high cost of battery technology, ev battery swapping technology and power exchange station construction made the technical scheme uncompetitive, and the project was terminated. China Southern Power Grid has also introduced the scheme of BP and has demonstrated its operation in Guangzhou and other places.
In 2009, China promoted the development of new energy vehicles. Since 2011, the State Grid has been the main force to promote the power swap mode. First, the State Grid (Hangzhou) Integrated Energy Services introduced semi-automatic battery switching in the standard box. In 2013, Xinxiang County Power Industry Bureau led the joint efforts of car companies and taxi companies to promote the taxi operation of chassis replacement, but failed to promote it.
In 2013, with the promotion of policy and technology development, China’s new energy development accelerated. Attempts to replace power are also expanding. State Grid power exchange project personnel set up an independent Bertan company to promote side wall power exchange and chassis power exchange in Hangzhou, Xi’an and other places.
Zhejiang Xinshikong’s side wall power exchange mode has made relative progress in technical verification through large-scale demonstration and operation in ev battery swapping.
In 2016, Aulton joined the power swapping operation, cooperated with other automobile companies to promote chassis power exchange, and successively carried out large-scale power exchange operations in Guangzhou, Xiamen and Beijing, China. Vehicle enterprises are trying on the technical route of ev battery swapping.
Introduction to the technical scheme of ev battery swapping
The ev battery swapping of trunk
The State Grid (Hangzhou) Integrated Energy Services battery swapping station takes 20 standard battery boxes as a group, and each box has about 5 kWh of electricity, which is loaded into the battery transfer box for centralized charging and power exchange.
The Hangzhou tram replacement model is mainly used for taxis and official vehicles. There are two types of ev battery swapping equipment: mechanical platform and movable forklift platform, which are fixed beside the car exchange position.
The battery box in the boot of the electric vehicle is pulled out and pushed in manually. This scheme of ev battery swapping is basically an initial attempt to change power in China.
Chassis and side wall ev battery swapping
The battery box of the pure electric vehicle is arranged at the bottom of the car, with two boxes of batteries on the left and two boxes on the right. After the battery is controlled to rise and fall in the car, the battery is taken out from the side by the robot.
● The ev battery swapping of side wall
The feature of this power exchange technical scheme is that the power exchange port of the battery is arranged on the side wall, the battery cabin door is opened by controlling, and then the battery is taken out and installed on the side of the manipulator. In this scheme, the battery is arranged on the chassis, which makes the body height higher and affects the vehicle performance.
● Chassis power change
The chassis power replacement scheme of ev battery swapping can be subdivided into two types: the standard battery box represented by State Grid Shanghai Electric Bus and the special-shaped battery pack represented by BP.
BP’s plan is that after the vehicle is in place, the vehicle will remain still, the mechanism under the ground will horizontally transmit the battery, lift the battery up and down to install the battery, and the servo motor will tighten and loosen the battery locking mechanism to complete the entire ev battery swapping action.
The “tower type” special-shaped battery for chassis replacement is arranged on the chassis between the rear seats and the boot. This scheme of ev battery swapping has the least change to the chassis frame, but still affects the rear row space and trunk volume.
Technical proposal for chassis power replacement
Among various power replacement technical solutions in ev battery swapping, chassis power replacement has been more recognized. At present, the most widely used structure is the flat structure arranged on the chassis, which basically does not occupy the riding space, boot space and vehicle height. The battery pack is fixed on the power exchange frame, which is adapted to the existing body structure and installed on the body floor.
During the ev battery swapping, the battery pack and the power change frame shall be disassembled as a whole. The battery module, the lower box assembly, the power distribution box, the battery management system and the upper box cover form a battery pack (PACK), which is then installed on the replacement motor assembly to form an integral replacement battery pack.
At present, the difference of chassis ev battery swapping technology mainly lies in the different locking methods. In the chassis ev battery swapping technical scheme, the replacement of the quick change battery pack is divided into two steps: lifting and locking. The lifting movement is vertical; The locking scheme is divided into rotary tightening/loosening and forward and backward translation.
Lifting and rotating tightening
BP and State Grid have adopted this scheme of ev battery swapping. The main action of the ev battery swapping is to lift the battery pack in place by the manipulator, and then rotate the locking mechanism, which is combined with the positioning on the chassis, clamped, tightened and locked. The locking points have obvious positioning grooves. Technically, the locking is more reliable, and the locking can be accurate.
Lifting and forward and backward translation
The main action of ev battery swapping: lift the battery pack in place by the manipulator, and then move the battery pack as a whole, relying on the seam, detent and lock on the chassis. In practical application, this scheme has the problems that locking is not easy to be in place and locking is loose.
Comparison of two technical solutions
● Weight
The rotary locking scheme of ev battery swapping has lighter weight, smaller locking range, better adaptability to different vehicle sizes, and lower requirements for chassis frame space.
● The ev battery swapping connector
The floating range of the exchange connector of the rotary locking scheme is larger, so the environmental adaptability is better, the weight is light, the matching size requirements are lower, and the battery can be expanded to adapt to different cooling modes.
● Service life
In terms of life, the life of key components of the two schemes of ev battery swapping is similar. However, in terms of comprehensive cost, the rotary locking scheme is better.
From the comparison of the above three aspects, the rotary locking scheme of ev battery swapping has more advantages, and has the most demonstration applications at present.
Summary
In addition to technical feasibility, the large-scale sustainable application of ev battery swapping mode also needs to further verify its economy through operation, as well as the generalization of different battery packs for different models.
It is believed that with the development of battery and other technologies and the rapid decline of costs, the ev battery swapping mode (power replacement technology scheme) will gradually occupy a specific market and promote the accelerated development of new energy vehicles.