|The integrated inverter in the current DENSO e-compressor is stacked above the motor. The new e-compressor debuting on the Ford vehicles improves the packaging by moving the inverter in-line with the motor. Click to enlarge.|
DENSO’s new inline electric compressor will make its global debut on Ford Motor Company’s Focus Electric, which began production this past December, with retail production ramping up the first half of the year. The inline e-compressor will also appear on the Fusion and C-MAX Hybrids and Energi Plug-in Hybrids, going on sale in North America this year.
DENSO introduced electric compressors for hybrid electric vehicles in 2003. In 2005, DENSO introduced an electric compressor, jointly developed with Toyota Industries Corporation, that incorporated an inverter to drive the built-in motor. This structure reduced the compressor size by approximately 60% compared with a conventional electric compressor and inverter (when they are assumed to provide the same output). DENSO miniaturized the inverter by using simplified circuits and a higher-density mounting with three-dimensional wirings.
The inverter for a conventional compressor is cooled by the engine’s coolant system. To be able to integrate the electric compressor and inverter, DENSO developed a new cooling method using air conditioning refrigerant in the compressor. DENSO’s segment conductor wiring method, which was developed for alternators in 2000, also reduced the size of the built-in motor.
|The current e-compressor with the integrated inverter stacked above the motor. The new e-compressor places the inverter in-line with the motor. Click to enlarge.|
DENSO’s newest inline e-compressor is smaller, lighter and quieter than previous generations. DENSO improved the packaging—allowing for easier under-the-hood component packaging—by repositioning the e-compressor’s integrated inverter in-line with the motor as opposed to the current integrated inverter that is stacked above the motor.
Despite the decrease in weight and size, the inline e-compressor maintains the same cooling capacity as the previous generation while consuming less power. This helps extend the lithium-ion battery range when the air-conditioning (A/C) is running. Also, for hybrid electric vehicles (HEV) and plug-in hybrid electric vehicles (PHEV), the e-compressor helps make the car less reliant on the internal combustion engine when running A/C.
Not only does the inline e-compressor keep the cabin cool, it also can cool the lithium-ion battery to help it maintain an optimal temperature, improving the battery’s range and overall longevity.
Conventional compressors are powered by an engine’s belt drive, but EVs don’t have belt-driven engines that energize the peripheral systems (Hence, the move to an electric-driven compressor). This electrified compressor has its own motor, inverter and circuit board.