- Good R&D plans have multiple milestones with clearly defined objectives at System AND Technology level. These milestones bring constituent technologies together to evaluate / guide integration.
- Good plans drive reuse of development between various development projects to reduce development costs and improve efficiency.
- Good plans have multiple points of insertion from technologies into delivered products - i.e. Different subsystems from different development projects mature at different times and get inserted into delivered products. These multiple insertion paths reduce long-term risks and improve return on investment.
"Mitsubishi Electric Corp developed a motor system whose output power is more than 70kW for electric vehicles (EVs) by integrating an inverter and a motor on the same axis."
This integration has many benefits including reduced volume, reduced weight and improved installation among others.
The integration enabled to shorten electric lines between the inverter and motor as well as to integrate pipes for water cooling that are required for each of the inverter and motor in the old system.This demonstrates one aspect of a good R&D plan: Clearly delineated objectives and goals. These goals should be measurable so that progress can be evaluated at multiple points along the development pipeline. The company plans to commercialize the system only in 2017. However, they are demonstrating some of the capabilities in the integrated system in 2012! It is important to address integration challenges early and not wait till technology development is complete.
The mass of the new system is about 10% less than that of the old one. And the total efficiency of the new system is 3-5 points higher than that of the old system under the JC08 test mode.
It is also important to identify major development hurdles and clearly define targets for technology development. In this case, the company has identified heat from the inverter as the key challenge and identified multiple technology development paths to address it. This clarity drives innovation:
Because the motor and inverter generate a large amount of heat, the company not only increased cooling capability but also made improvements to each of the motor and inverter to reduce heat generation. Specifically, it changed the magnetic design of the motor and employed a silicon carbide (SiC)-based power device for the inverter. With the SiC-based power device, the loss of the inverter was reduced by half, compared with the inverter of the old system that uses a silicon (Si)-based power device.Since development of power devices is expensive, they have insertions of the SiC devices before the final system delivery. Multiple insertion paths reduce the risk of wasted development effort:
The company aims to commercialize the system in 2017. And it plans to commercialize an EV motor system whose inverter using a Si-based power device and motor are separated in 2014.Finally, there are incremental objectives for development at each stage, further enhancing management's ability to monitor and guide R&D:
Currently, the motor system can be used for rotating tires and for simulated driving based on actual driving patterns in a laboratory. To commercialize the system, it is necessary to improve its structure for volume production, fine-tune it and further reduce its weight by 10 to 20%, Mitsubishi Electric said.