The present disclosure relates generally to the battery systems for vehicles deriving at least a portion of their motive power from an electrical power source. More specifically, the present disclosure relates to systems and methods used to pre-charge a bus capacitance in vehicles using parallel battery packs.
This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present disclosure, which are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present disclosure. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.
Vehicles, such as cars, trucks, and vans, are widely used to facilitate the movement of people and goods in modern society. Vehicles may utilize a number of different energy sources (e.g., a hydrocarbon fuel, a battery system, a capacitance system, a compressed air system) to produce motive power. For example, certain vehicles may include a battery system and use electric power for part or all of their motive power.
In general, such vehicles may provide a number of advantages as compared to traditional, gas-powered vehicles that solely rely on internal combustion engines for motive power. For example, such vehicles may produce fewer undesirable emission products and may exhibit greater fuel efficiency as compared to vehicles using only internal combustion engines to propel the vehicle.
To conserve stored energy, the battery systems used to provide motive power for vehicles may be disconnected from the vehicle's power systems when the vehicle is not in operation. Because of the large voltage difference and the bus capacitance between the battery systems and the disconnected power systems, immediately reconnecting a battery system to a disconnected power system on the vehicle may cause a large inrush of current into the bus capacitance, potentially damaging both the battery and the power system. Hence, pre-charging systems have been developed that are designed to limit the inrush current of a battery system until the bus capacitance is sufficiently charged. These pre-charging systems often include a pre-charge resistor that may be connected in series between the battery system and the bus capacitance until the bus capacitance is charged. The capacitance of the bus capacitance and the resistance of the pre-charge resistor effectively form an RC circuit, causing a delay in the pre-charge system in relation to the RC time constant of the RC circuit.