Battery pack manager
A manager that lessens a difference in state of charge of a battery pack. The battery pack is constituted of a plurality of blocks. A slave unit is provided for each of the blocks, to thus detect a terminal voltage of the block and supply the detected terminal voltage to a master unit. A difference arises in state of charge among the blocks for reasons of a difference in current consumption of the respective slave units. The master unit makes up an operation clock signal for each of the slave units from a high frequency signal and a low frequency signal. A difference in state of charge among the blocks is lessened by controlling an appearance ratio of the high frequency signal to the low frequency signal for each of the slave units.
1. A manager that manages a state of charge of a battery pack, comprising:
a plurality of low level control means that each individually control a plurality of series-connected battery blocks constituting the battery pack and that are supplied with electric power from each of the plurality of battery blocks; and
high level control means that generates each of operation clock signals for the plurality of low level control means from at least two signals, a high frequency signal and a low frequency signal, and that lessens a difference in state of charge among the battery blocks to be controlled by the plurality of corresponding low level control means by controlling an appearance ratio of the high frequency signal to the low frequency signal.
2. The manager according to claim 1 , wherein
the plurality of low level control means detect terminal voltage of battery cells constituting each of the battery blocks to be controlled by the respective low level control means and supply the detected terminal voltages to the high level control means; and
the high level control means detects a difference in state of charge from the terminal voltages of the battery blocks and control the appearance ratio according to the difference in state of charge.
3. The manager according to claim 2 , wherein the high level control means performs control operation so as to increase the appearance ratio of the high frequency signal in connection with low level control means that controls a battery block exhibiting a relatively higher state of charge.
4. The manager according to claim 1 , wherein the high level control means controls the appearance ratio according to a difference among consumed current values generated as a result of the plurality of low level control means operating by means of the high frequency signal.
5. The manager according to claim 4 , wherein the high level control means performs control operation in such a way that low level control means exhibiting a relatively greater consumed current value is given a larger appearance ratio of the low frequency signal.
6. The manager according to claim 5 , wherein the high level control means sets the appearance ratio of the low level control means, among the plurality of low level control means, that exhibits a relatively greater consumed current value generated as a result of the low level control means having operated by means of the high frequency signal and also sets the appearance ratio for the other low level control means such that a difference between an average consumed current value generated as a result of the low level control means having operated by means of the set appearance ratio and an average consumed current value of the other low level control means becomes minimum.
7. The manager according to claim 1 , wherein the high level control means controls the appearance ratio by means of taking the operation clock signal appearing in a first period “t” of a control period T (t<T) as the high frequency signal and the operation clock signal appearing in a remaining T−t period as either the high frequency signal or the low frequency signal.
8. The manager according to claim 1 , wherein the low frequency signal is a signal generated by frequency division of the high frequency signal.
9. A manager for managing remaining capacity of a battery pack comprising:
a plurality of low level control means that each individually control a plurality of series-connected battery blocks constituting the battery pack and that are supplied with electric power from each of the plurality of battery blocks; and
high level control means that generates each of operation clock signals for the plurality of low level control means from at least two signals, a high frequency signal and a low frequency signal, and that lessens a difference in remaining capacity among the battery blocks to be controlled by the plurality of corresponding low level control means by controlling an appearance ratio of the high frequency signal to the low frequency signal.