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Renesas introduces small, 100kW-class inverter solution for HEVs and EVs

Renesas Electronics Corporation announced its new 100kW-class inverter solution that achieves industry-leading small volume of 3.9 liter (L) for high-power 100kW-class motors in mid- to large-sized hybrid electric vehicles (HEVs) including SUVs, and mid- to small-sized electric vehicles (EVs).

Renesas will provide a solution kit including software that maximizes the HEV/EV motor performance and hardware components such as microcontrollers (MCUs), Insulated Gate Bipolar Transistor (IGBT) and fast recovery diode (FRD), and other power semiconductor devices.


The new solution enables system developers to reduce development time for various development steps: from specifications analysis to hardware/software development and motor characteristic adjustments. This shortens, for example, the prototyped inverter system development period from two- to three years to just one year, thereby significantly contributing to the reduction of the development cycle and costs.

In an electrically powered system, the inverter plays a key role converting direct current (DC) power to alternating current and sends out optimum current to the motor whose rotation speed varies according to the driving conditions.

Renesas has been releasing inverters and solution kits with various capacity designs. In 2014, Renesas developed a solution that realized a size of 2.9 L in the 50 kW class. To respond to the growing needs for large-output motors for use in large vehicles, Renesas has expanded its lineup to support these large-output motors with its new 100kW class inverter solution included with a motor calibration tool.

Key features of the new 100 kW class inverter solution:

  • Industry-leading volume and reduced inverter system weight enable mounting in even smaller spaces. The size and weight of the heat sink included in an inverter can be reduced by employing the temperature management technology that increases the responsiveness and precision of the temperature sensors integrated in the IGBT.

    In addition, the included MCU has an integrated enhanced motor control unit (EMU) function that enables motor control to be performed by a dedicated circuit instead of the CPU. This offloads the CPU to take on the CPU processing for the external automotive control unit (known as an electronic control unit, ECU), including the DC/DC converter, second motor, and cooling pump processing. This enables effective automotive ECU integration leading to improved use of the limited space in the engine compartment.

  • Shortens development period by more than 50% with software that allows quick evaluation in actual cars. In addition to hardware, the inverter solution includes a motor calibration tool that maximizes the motor performance. This simplifies construction of motor control systems that are highly efficient at the system level. This allows system manufacturers immediately to evaluate a prototyped inverter system in an actual car.

  • Higher fuel and electric power efficiency with devices optimized for HEV/EV applications. By using IGBT/FRD devices for reduced low conduction loss and low switching loss, the new inverter solution achieves a current loss reduction of approximately 12%, compared to existing Renesas products.

    By including Renesas main devices that are specialized for HEV and EVs, the new solution reduces the inverter’s power loss by approximately 10%. This enables increased motor efficiency, which ultimately contributes to increased fuel and electric power efficiency of the inverter system. The new solution is equipped with the RH850/C1H MCU Series, which has an industry-proven resolver-to-digital converter (RDC) function to convert the motor’s rotation angle from analog to digital. The RH850/C1H achieves high-precision motor control of up to 12 to 16 bits. The solution also includes the R2A25110 driver IC with micro-isolator technology enabling high-speed switching.

    Micro-isolators are circuits that combine signal transmission and isolation functions using transistors formed using the interconnect layers on the semiconductor chip.

Renesas will be introducing the 100 kW class inverter solution, including presenting demonstrations using the new solution, at Renesas DevCon Japan 2017.



This is good news and constitutes increased competition in the more efficient inverter field.


That's amazingly small. The total volume is about one third the size of a standard shoe box. I remember when these things were the size of a small suitcase just about 5 years ago.


Dave , 3.9 L equals 239 cub inches, I don't believe it is as small as you say


Jimr, we forget what the cube function means sometimes. To us un-metricized Americans, that's a cube six and a quarter inches per side. That's SMALL, expecially when you consider it can work with a variety of electromagnetic "mates" and apparently not tightly coupled (so feeder noise is an issue as well).

This is one of the key sea changes coming in cars: the absolute commoditization of high-performance power electronics. There's no reason for car manufacturers ("integrators") to be in the motor drive business.


Ooops, I missed your point, Jimr, which was about the comparison to a shoebox.

Here's a U-line standard box for "children's shoes" at 9 x 7 x 4 = 252in^3 (228mm x 178mm x 101 = 4.1 liters)

This does not come close to holding my size 13D Clown attire. (That's MY version of a shoe box and I'd be impressed even then to hold 100kW of motor drive.)


This is a reference design, all chip makers have them.


Do "all chip makers" generally have a "reference design" for a complete subsystem/system with their products? I have not noticed an Intel's refernce design for a Laptop or a Tablet, for example. I have not seen Cree's reference design for a complete motor drive or DC-to-DC converter with all the bits.

I think you're incorrect.


All chip makes have reference designs but not for all chips and all configurations, even Intel has them.


Interesting that they are saving all this space and weight; but, we are still using heavy, large lead acid 12 volt batteries in EVs for car control.


How is the DC motor technology coming along? It would be nice not to lose 12% power inverting DC to AC.


Considering an ICE wastes 70% no problem.


SJC- Not so fast. A cursory lookup of typical power plants.

Most common Coal 41% of global power production 32%-42%
Most common gas turbine (single cycle) 32%-38%
Diesel 35%-42%

Also, by the time the "fuel" gets to recharge a battery per grid efficiency loss, that is another -7%. Don't forget battery charge losses to get the energy in the tank value. The fossil fuel power plants consume fuel. The fuel must be transported to the power plant. This occurs when fueling up conventional vehicle, also.

One needs to consider the power plants don't operate at peak efficiency, especially when supporting power production with unreliable power generation. The same for ICE engines that need to vary horsepower.

The ICE really operates in a combination cycle. The thermal energy production to heat cabin and batteries should be included in energy efficiency. Also, the engine generates power to recharge batteries. This should be added to engine efficiency. I remember reading of Toyota passing a threshold of 40% engine efficiency, last year for a new engine. Manufacturers are improving engine efficiency faster than grid is improving. The hybrid technology is the game changer and stack that on top of bio fuel low carbon fuel I don't see any environmental advantage to battery car. I don't think there is, but cities will have cleaner air with BEVs. Maintenance will drop and car will be quiet, smaller, and probably cheaper transport. Most of the world will continue with ICE technology. Heavy torque requirements will most likely continue with fuel energy.


I have outlined all this years ago, it is on the record here.

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