Renesas Electronics Corporation today announced its new 100 kW class inverter solution that achieves industry-leading small design class of 3.9 liter (L) for high-power 100 kW class motors in mid- to large-sized hybrid electric vehicles (HEVs) including SUVs, and mid- to small-sized electric vehicles (EVs).
Renesas will provide the new solution as a solution kit that includes 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, a reduction of over 50 percent, thereby significantly contributing to the reduction of the development cycle and costs.
CO2 emissions are rising due to abnormal weather events caused by global warming and increased levels of environmental pollution. For the automotive industry, this is driving increasing demand for broad adoption of electrically powered systems, such as HEV and EVs, at an earlier stage to reduce these emissions.
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. Therefore, to realize an inverter system with higher fuel and electric power efficiency, high precision and high efficiency of the motor drive in addition to miniaturization of the inverter is required to allow mounting of the electric unit in the limited space of the engine room for every type and size of vehicle model. Renesas’ new inverter solution addresses these needs.
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 100 kW class inverter solution included with a motor calibration tool.
Key features of the new 100 kW class inverter solution:
(1) Industry-leading small design class of 3.9 L 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 room.
(2) Shortens development period by more than 50 percent 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 to immediately evaluate a prototyped inverter system in an actual car, which can shorten, for example, a three- to two-year prototyped inverter system development period into just one year, a reduction of over 50 percent.
(3) 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 percent (Note 1).
By including Renesas main devices that are specialized for HEV and EVs, the new solution reduces the inverter’s power loss by approximately 10 percent (Note 1). 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 (Note 2) enabling high-speed switching.
Renesas will be introducing the 100 kW class inverter solution, including presenting demonstrations using the new solution, at Renesas DevCon Japan 2017.
(Note 1) Compared to existing Renesas products
(Note 2) Micro-isolators are circuits that combine signal transmission and isolation functions using transistors formed using the interconnect layers on the semiconductor chip.