System and method for balancing state of charge among series-connected electrical energy storage units
First Claim
1. A system for balancing state of charge among a string of plural series connected electrical energy storage units, comprising:
- a string of electrical energy storage units, each storage unit having a state of charge, each state of charge being a fraction of a fully charged capacity for each storage unit; and
a circuit configured to selectively monitor the state of charge of each storage unit at least when a storage unit is being charged or discharged, and to transfer energy from a selected storage unit to the string of storage units when the state of charge of the selected storage unit is greater than a target state of charge to converge the state of charge of the selected storage unit toward the target state of charge.
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Accused Products
Abstract
A system and method of balancing state of charge among plural series connected electrical energy storage unit is provided. Individual storage units are selectively coupled by semiconductor switches for monitoring and balancing state of charge. When the state of charge of a selected unit is greater than a target state of charge, energy is transferred from the selected unit to the string of storage units, such that the state of charge of the selected unit converges toward the target state of charge. Conversely, when the state of charge of a selected unit is less than a target state of charge, energy is transferred from the string of storage units to the selected unit, such that the state of charge of the selected unit converges toward the target state of charge.
174 Citations
45 Claims
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1. A system for balancing state of charge among a string of plural series connected electrical energy storage units, comprising:
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a string of electrical energy storage units, each storage unit having a state of charge, each state of charge being a fraction of a fully charged capacity for each storage unit; and a circuit configured to selectively monitor the state of charge of each storage unit at least when a storage unit is being charged or discharged, and to transfer energy from a selected storage unit to the string of storage units when the state of charge of the selected storage unit is greater than a target state of charge to converge the state of charge of the selected storage unit toward the target state of charge. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 40)
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22. A system for balancing state of charge among plural series connected electrical energy storage units, comprising:
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a string of electrical energy storage units, each storage unit having a state of charge, each state of charge being a fraction of a fully charged capacity for each storage unit; and a circuit configured to selectively monitor the state of charge of each storage unit at least when a storage unit is being charged or discharged, and to transfer energy from a selected storage unit to a non-dissipative load when the state of charge of a selected storage unit is greater than a target state of charge to converge the state of charge of the selected storage unit toward the target state of charge. - View Dependent Claims (23, 41)
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24. A system for balancing state of charge among plural series connected electrical energy storage units, comprising:
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a string of electrical energy storage units, each storage unit having a state of charge, each state of charge being a fraction of a fully charged capacity for each storage unit; and a circuit configured to selectively monitor the state of charge of each storage unit at least when a storage unit is being charged or discharged, and to transfer energy between the selected storage unit and the string of storage units when the state of charge of a selected unit is different than a target state of charge, to converge the state of charge of the selected storage unit converges toward the target state of charge. - View Dependent Claims (42)
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25. A method for balancing state of charge among plural series connected electrical energy storage units, comprising:
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selectively monitoring the state of charge of each storage unit in a string of electrical energy storage units at least when a storage unit is being charged or discharged, each state of charge being a fraction of a fully charged capacity for each storage unit; and when the state of charge of a selected storage unit is greater than a target state of charge, transferring energy from the selected storage unit to the string of storage units, such that the state of charge of the selected storage unit converges toward the target state of charge. - View Dependent Claims (26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 43)
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37. A method for balancing state of charge among plural series connected electrical energy storage units, comprising:
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selectively monitoring the state of charge of each storage unit in a string of electrical energy storage units at least when a storage unit is being charged or discharged, each state of charge being a fraction of a fully charged capacity for each storage unit; and when the state of charge of a selected storage unit is greater than a target state of charge, transferring energy from the selected storage unit to a non-dissipative load, such that the state of charge of the selected storage unit converges toward the target state of charge. - View Dependent Claims (38, 44)
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39. A method for balancing state of charge among a string of plural series connected electrical energy storage units, comprising:
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selectively monitoring the state of charge of each storage unit in a string of electrical energy storage units, the selected storage unit being monitored at least when a storage unit is being charged or discharged, each state of charge being a fraction of a fully charged capacity for each storage unit; and when the state of charge of a selected storage unit is different than a target state of charge, transferring energy between the selected storage unit and the string of storage units, such that the state of charge of the selected storage unit converges toward the target state of charge. - View Dependent Claims (45)
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Specification