Integrated multiple power conversion system for transport refrigeration units

Abstract

The invention relates to an electrical subsystem to power a vehicle refrigeration system. The electrical subsystem includes an AC drive electrically coupled to a high voltage DC bus. The AC drive provides 'refrigeration compressor AC power' responsive to a cooling demand. The electrical subsystem also includes a 'low voltage DC bus'. The low voltage DC bus powers a plurality of low voltage refrigeration components including refrigeration fans. A microcontroller sets the compressor AC voltage and the compressor AC frequency. A method of preventing vehicle refrigeration system compressor stall includes the step of limiting the electrical AC power to the compressor such that the AC voltage does not droop causing a compressor stall. Also, an electrical subsystem for powering a compressor in a vehicle refrigeration system includes 'V / f' operating information for the compressor, and a microcontroller commands the AC voltage and the AC frequency to the compressor.

Description

technical field [0001] The present invention relates generally to vehicle electrical subsystems, and more particularly to vehicle electrical subsystems for powering a vehicle refrigeration system. Background technique [0002] Most motor vehicles, including trucks and buses, get their power from an internal combustion engine. The electrical power to run the various electrical systems on a vehicle is typically produced by a generator, which is mechanically driven by the engine. Typically, these generators have a rotor that is mechanically coupled to a drive belt driven by the engine. AC generators are the most common type of power generating device used in this application. [0003] The advent of electrical generators of all kinds has allowed vehicle air conditioning systems to operate on an electrical basis, as opposed to using engine-driven mechanical refrigeration compressors. One such early system is disclosed in US Patent No. 6925,826 to Hille et al. and assigned to C...

AI Technical Summary

Problems solved by technology

However, when the vehicle motor is stopped, the vehicle battery charging system is no longer charging the DC battery, which makes the vehicle DC battery bus less suitable for operating cooling components

[0005] One problem is that the vehicle's cooling system cannot usually be allowed to shut down when the vehicle's engine is switched off

Another problem is that vehicle refrigeration systems typically require more power than air conditioning systems, and typically require several AC and DC power supplies of different voltages, each of the different refrigeration subsystems typically requiring a unique electrical subsystem to power them

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