Are you looking for laser cutting china supplier?Wonder industries ltd., Has More Than 15 year's Professional Experience In The Precision Laser Cutting And Sheet Metal And Other Cutting Service To Suit All Your Needs.Get Instant Quote:[email protected] .

How to reduce the cost of electric vehicles and increase the driving range through integrated powertrain systems

How to reduce the cost of electric vehicles and increase the driving range through integrated powertrain systems

If more automotive applications can be realized with fewer devices, it will not only reduce vehicle weight, reduce costs, but also improve reliability. This is the idea behind the design of integrated electric vehicles (EV) and hybrid electric vehicles (HEV).

If more automotive applications can be realized with fewer devices, it will not only reduce vehicle weight, reduce costs, but also improve reliability. This is the idea behind the design of integrated electric vehicles (EV) and hybrid electric vehicles (HEV).

What is an integrated powertrain?

The integrated powertrain is designed to combine terminal equipment such as on-board chargers (OBC), high-voltage DC/DC (HV DCDC) converters, inverters, and power distribution units (PDUs). The mechanical, control or powertrain level can be integrated, as shown in Figure 1.

How to reduce the cost of electric vehicles and increase the driving range through integrated powertrain systems
Figure 1: Overview of a typical architecture of electric vehicles

Why is powertrain integration beneficial to hybrid/electric vehicles?

Integrated powertrain terminal equipment components can achieve the following advantages:

• Improve power density.
• Improve reliability.
• Optimize costs.
• Simplify design and assembly, and support standardization and modularization.

High-performance integrated powertrain solutions: the key to the popularization of electric vehicles

Read the white paper

Market application status

There are many ways to achieve an integrated powertrain. Figure 2 takes the integration of an on-board charger and a high-voltage DC/DC converter as an example, and briefly introduces four common methods used to achieve high power density when combining powertrains, control circuits, and mechanical components. they are, respectively:

• Method 1: Form an independent system. This method is not as popular as it was a few years ago.

• Method 2: It can be divided into two steps:

The DC/DC converter and the on-board charger share a mechanical casing, but have their own independent cooling system.
At the same time share the housing and cooling system (the most commonly used method).

• Method 3: Perform control-level integration. This method is evolving into the fourth method.

• Method 4: Compared with the other three methods, this method has a greater cost advantage due to the reduction of power switches and magnetic components in the power circuit, but its control algorithm is also more complicated.

How to reduce the cost of electric vehicles and increase the driving range through integrated powertrain systems
Figure 2: Four common methods of integration of on-board chargers and DC/DC converters

Table 1 summarizes the integration architecture currently on the market.

High-voltage three-in-one integration that can reduce electromagnetic interference (EMI): integration of on-board chargers, high-voltage DC/DC converters, and power distribution units
(Method 3)

Integrated architecture: integration of car charger and high voltage DC/DC converter
(Method 4)

43kW charger design: integration of on-board charger, traction inverter and traction motor (Method 4)

・6.6kW car charger
・2.2kW DC/DC converter
・Power distribution unit

*Third-party data reports show that this type of design can reduce volume and weight by about 40%, and increase power density by about 40%

・6.6kW car charger
・1.4kW DC/DC converter
・Magnetic integration
・Shared power switch
・Shared control unit
(A microcontroller[MCU]Controlled power factor correction stage, a microcontroller-controlled DC/DC stage, and a high-voltage DC/DC converter)

・AC charging power up to 43kW
・Shared power switch
・Shared motor windings

Table 1: Three successful realizations of powertrain integration

With the help of C2000 real-time microcontrollers (such as the newly released TMS320F280039C-Q1MCU), EV and HEV powertrain designers can target on-board chargers-power factor correction, on-board chargers-DC/DC converters and high-voltage to low-voltage DC/DC The application adopts a discrete and integrated architecture. In addition, TMS320F280039C-Q1 can realize real-time control and management of multiple power levels through a single MCU, thereby reducing the size of the powertrain and reducing costs. Multiple reference designs show how to use a single MCU to achieve the integration of multiple powertrain subsystems.

Table 2 shows the C2000 MCU product series that can help designers realize a variety of discrete and integrated powertrain topologies.

Design requirements

OBC PFC

OBC DC/DC

High voltage to low voltage DC/DC

Low isolation cost

F28002x

F28003x

F28003x

Modular development

F28004x/F28003x

F28003x

F28002x

F28004x/F28003x

Integrated real-time control

F2837x/F2838x

Table 2: Recommended C2000 microcontrollers for different levels of powertrain integration

Powertrain integration block diagram

Figure 3 is a block diagram of a powertrain that implements an architecture of power switch sharing and magnetic integration.

How to reduce the cost of electric vehicles and increase the driving range through integrated powertrain systems
Figure 3: Power switch and magnetic component sharing in an integrated architecture

As shown in Figure 3, both the on-board charger and the high-voltage DC/DC converter are connected to the high-voltage battery, so the full-bridge rated voltages of the on-board charger and the high-voltage DC/DC converter are the same. In this way, the on-board charger and the high-voltage DC/DC converter can share the power switch through the full bridge.

In addition, integrating the two transformers shown in Figure 3 can also achieve magnetic integration. This is because they have the same rated voltage on the high-voltage side and can finally form a three-terminal transformer.

Performance improvement

Figure 4 shows how the built-in step-down converter can help improve the performance of the low-voltage output.

How to reduce the cost of electric vehicles and increase the driving range through integrated powertrain systems
Figure 4: Improve the performance of low-voltage output

When this integrated topology works under high-voltage battery charging conditions, the high-voltage output can be precisely controlled. However, because the two terminals of the transformer are coupled together, the performance of the low-voltage output will be limited. There is a simple way to improve low-voltage output performance, and that is to add a built-in buck converter. But the price of doing so is that it will lead to increased costs.

Shared components

Like the integration of an on-board charger and a high-voltage DC/DC converter, the power factor correction stage in the on-board charger is very close to the rated voltages of the three half-bridges. As shown in Figure 5, this allows the three half-bridges shared by two terminal equipment components to share the power switch, thereby reducing costs and increasing power density.

How to reduce the cost of electric vehicles and increase the driving range through integrated powertrain systems
Figure 5: Component sharing in powertrain integrated design

Since a motor generally has three windings, these windings can also be used as power factor correction inductors in on-board chargers to achieve magnetic integration. This also helps reduce design costs and increase power density.

Concluding remarks

From low-level mechanical integration to high-level Electronic integration, the development of integration continues. As the integration level increases, the complexity of the system will also increase. However, each architecture variant brings different design challenges, including:

• To further optimize performance, magnetic integration must be carefully designed.
• When using an integrated system, the control algorithm will be more complicated.
• Design an efficient cooling system to meet the cooling needs of smaller systems.

Flexibility is the key to powertrain integration. There are many methods for you to choose, and you can explore various levels of integrated design at will.

The Links:   B150XG01-V2 EPCS16SI16N