Two million kilometers guarantee the durability of in-wheel electric motors – technology – hybrid and electric cars

The British company Protean Electric, founded in 2008, brings together more than 160 patents worldwide Related to the design of electric motors and power electronics. It also has another 150 applications for patents related to manufacturing control. Chris Hilton, its chief technology officer, explained International vehicle testing technology What is there Inside the wheels of these electric cars And what advantages does it add compared to the over-axle motors.

The Protean engine is a machine from Permanent magnets What it includes Power and control electronics Packed inside the wheel itself and capable of production High power and torque density. These systems have so far been produced in small quantities and directed to manufacturers and suppliers to have real tests with them. Protean has developed and implemented wheeled electric propulsion systems to Hybrid, hybrid and all-electric cars The battery has been charged. According to the company, its trial and test models have already traveled more than Two million kilometers Vehicle on motor vehicles.

Chris Hilton, Protean Chief Technology Officer.

Technology basis

Protean chief technology officer Chris Hilton explains that the ProteanDrive etc. It is an integrated package that includes All essential powertrain technologies in one compact unit. The kit inside the frame includes a permanent magnet synchronous motor and the power electronics that control it. External specialist cooperation in wheel-engine compatibility Maintaining a regenerative engine braking system. The rotor of the electric motor is directly connected to the axle, that is, it delivers torque directly to the wheel, andReducing losses in power transmission. This direct-drive configuration is reflected in the high-speed, low-torque ProteanDrive design.

In design, The motor is not in direct contact with the rimExcept for the point where the bearing is located. This ensures sufficient space for even the most serious damage to the wheel rim. Do not cause engine damage. Protean ensures that a heavy enough hit on the pavement to damage the suspension won’t damage the engine. “We understand that it is an expensive item that the vehicle owner will not want to replace due to a minor accident,” says Hilton.

Hypothetical tests

An essential part of the methodology to design and verify the operation of the motors inside the wheels Is modeling and simulation at the subsystem and whole system level. Without that, coming up with a product that meets all requirements and is competitive will be an impossible task. ” Utilization Finite Element Calculations It offers the best simulation results and provides accurate information on the electromagnetic performance of the motor, the thermal behavior and the mechanical integrity of the structure.

The Dynamics of arithmetic flow It allows to study the coolant flow through the engine, ensuring that it can operate effectively even at high wheel speeds, to avoid the effects of back pressure or bore. Finally, through Spice simulator (Simulation program with an emphasis on integrated circuits), Simulation program for integrated circuits, the behavior of electronics is examined.

An exploding view of Protein’s electric wheel motors.

These simulations can in themselves be very accurate, but they do not solve the uncertainties that exist about the behavior of materials at the intersections between them. For this reason, it is necessary to relate virtualization to actual measurements in Laboratory conditions. The only Protean serving is headquartered in Farnham, UK, and has a wide range of equipment that allows most aspects of in-house engines to be tested.

Lab tests are an important part of the job because they allow you to verify that the product’s functionality, performance, and durability are suitable for use in the real world. Before proceeding with a full assembly verification, every building block used in the design is tested At the level of materials, components and connections between them.

As it is a new product, these tests include Development of specific equipment and innovative procedures That allows checking aspects that are not considered in a more traditional central system. Even in common aspects, such as protection from vibration, testing is performed at levels much stricter than those used in conventional powertrains, with the “extreme environment we know our product will need to survive”.

After running each model and adjusting the parameters as indicated in the laboratory experiments, The simulation achieved a high rate of accuracy, Indicating that physical tests with real prototypes should respond in a very similar way to what the tests predicted.

Most of the simulations Protean performs relate to the locomotor system, but are sometimes necessary Full car model. Wheel motors provide great opportunities to improve a vehicle’s dynamic behavior by taking advantage of their ability to assign different torque to each of the drive wheels. For this purpose, modeling software is used to generate the best algorithms based on vehicle dynamics that simulate the effect of motors on wheels.

Real tests

“We have worked with dozens of customers who have integrated our engines into their cars and tested them in various ways. So far, our engines have completed more than two million kilometers of testing and It guarantees a useful life of 300,000 kilometersHilton says.

One of the test vehicles applying in-wheel electric motors from Protean.

The types of vehicles tested vary widely: Passenger cars, SUVs and light commercial vehicles. The tests they undergo range from evaluating the dynamometer on the Dyno to the overall durability of vehicles, both off-road and off-road. “Having passed it, we have great confidence in our engines’ ability to survive whatever life in the car is.” Hilton confirms that Protean is constantly working to improve product durability, but tests conducted so far ensure that “our engines pass complete durability tests for the entire life of the vehicle without failure”.

To ensure durability The tests are designed Certification that will demonstrate that the specified requirements have been met. Protean has worked with original equipment manufacturers for Meet your expectations Regarding an item like this Prone to harsh environment. Includes resistance and durability against shock, vibration, water, dust and other materials that wheel motors may be exposed to. “We adopt the most stringent requirements we can find so that we are confident that our engines will meet our customers’ expectations for durability.

Once you’ve tested the design in the simulation, the next step is Durability tests Which is performed initially at the sub-component level, then on the fully formulated product, and finally on the actual compounds. “We have not found applications in such a harsh environment where the motors inside the wheel cannot meet durability standards.”