Battery control method for hybrid vehicle
AssigneesDenso Corporation, Nippon Soken, Inc.
InventorsShoji Sakai, Tetsuya Kobayashi
Life of this patent
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Abstract
A battery control system is provided which charges or discharges a storage battery installed in a hybrid vehicle to bring a state-of-charge of the storage battery into agreement with a target one. The system determines whether the state-of-charge lies within a given narrower range defined around the target state-of-charge and corrects the state-of-charge based on an open-circuit voltage of the battery when the state-of-charge lies within the given narrower range, thereby eliminating a cumulative error in calculating the state-of-charge of the battery caused by a variation in charge/discharge efficiency of the battery.
Claims21
A battery control method of charging or discharging a storage battery installed in a hybrid vehicle to bring a calculated state-of-charge of the storage battery into agreement with a target state-of-charge, comprising the steps of:
- determining an open-circuit voltage of the storage battery installed in the hybrid vehicle using a voltage developed across the storage battery and a current flowing into or out of the storage battery in a given voltage-to-current relation of the storage battery;
- totalizing an amount of current flowing into or out of the storage battery in a cycle to calculate a state-of-charge of the storage battery;
- comparing the open-circuit voltage with a reference voltage which corresponds to a reference state-of-charge predetermined in a state-of-charge correction range defined around a target state-of-charge of the storage battery;
- and
- correcting the state-of-charge of the storage battery when the state-of-charge lies within the state-of-charge correction range by brining the state-of-charge close to the reference state-of-charge based on a result of comparison between the open-circuit voltage and the reference voltage.
A battery control method of charging or discharging a storage battery installed in a hybrid vehicle to bring a calculated state-of-charge of the storage battery into agreement with a target state-of-charge, comprising the steps of:
- determining an open-circuit voltage of the storage battery installed in the hybrid vehicle using a voltage developed across the storage battery and a current flowing into or out of the storage battery in a given voltage-to-current relation of the storage battery;
- totalizing an amount of current flowing into or out of the storage battery in a cycle to calculate a state-of-charge of the storage battery;
- determining whether the storage battery has been charged so that the state-of-charge of the storage battery increases out of a preselected state-of-charge range defined around the target state-of-charge or not;
- determining whether the open-circuit voltage has reached a high open-circuit voltage higher than a reference voltage which corresponds to a reference state-of-charge predetermined in the state-of-charge range or not;
- and
- discharging the storage battery until the state-of-charge reaches a given value smaller than the preselected state-of-charge range by a given amount when it is determined that the open-circuit voltage has reached the high open-circuit voltage.
A battery control method of charging or discharging a storage battery installed in a hybrid vehicle to bring a calculated state-of-charge of the storage battery into agreement with a target state-of-charge, comprising the steps of:
- totalizing an amount of current flowing into or out of the storage battery in a cycle to calculate a state-of-charge of the storage battery;
- determining whether the storage battery has been discharged until the state-of-charge of the storage battery decreases by a given amount out of a preselected state-of-charge range defined around the target state-of-charge or not;
- and
- charging the storage battery until the state-of-charge reaches a given value higher than the preselected state-of-charge range by a predetermined amount when it is determined that the storage battery has been discharged until the state-of-charge of the storage battery decreases by the given amount.
A battery control method of charging or discharging a storage battery installed in a hybrid vehicle to bring a calculated state-of-charge of the storage battery into agreement with a target state-of-charge, comprising the steps of:
- determining an open-circuit voltage of the storage battery installed in the hybrid vehicle using a voltage developed across the storage battery and a current flowing into or out of the storage battery in a given voltage-to-current relation of the storage battery;
- totalizing an amount of current flowing into or out of the storage battery in a cycle to calculate a state-of-charge of the storage battery;
- determining whether the storage battery has been charged so that the state-of-charge of the storage battery increases out of a preselected state-of-charge range defined around the target state-of-charge or not;
- determining whether the open-circuit voltage has exceeded a high open-circuit voltage higher than a reference voltage which corresponds to a reference state-of-charge predetermined in the preselected state-of-charge range or not;
- and
- correcting said reference voltage by a preselected value when it is determined that the open-circuit voltage has exceeded the high open-circuit voltage.
Dependencies are inferred from the claim text.