System comprising a battery formed by battery modules, and corresponding method for connecting or disconnecting a battery module
A system and corresponding method, including a battery including a plurality of battery modules arranged in series, each module including a switch and a diode arranged in series and connected in parallel to the module. The system further includes a capacitor connected directly by an electrical connection to a point situated between the diode and the switch of each module, and directly to the negative terminal of the battery, and a load connected in parallel to the capacitor, a mechanism controlling each module switch using a pulse width modulation signal having a duty cycle that varies between 0% and 100%.
1. A system for progressively increasing voltage at terminals of an input capacitor, comprising:
a battery including a plurality of battery modules arranged in series, each said battery module including a switch, a diode, and a plurality of battery cells, the switch and the diode being arranged in series and connected in parallel to the plurality of battery cells,
wherein each said battery module includes:
a positive terminal connected between the switch and a cathode of the diode, and
a negative terminal connected to the plurality of battery cells and to an anode of the diode,
wherein the battery modules are connected in series so that the positive terminal of a last battery module of the plurality of battery modules is connected to a positive terminal of the battery, the negative terminal of the first battery module of the plurality of battery modules is connected to a negative terminal of the battery, and the modules are connected so that the positive terminal of each battery module of the plurality of battery modules is connected to the negative terminal of a next battery module of the plurality of battery modules;
the input capacitor connected directly by an electrical connection to the positive and negative terminals of the battery;
a load connected in parallel to the input capacitor;
means for controlling the switch of each of the battery modules using a pulse width modulation signal having a duty cycle that varies between 0% and 100%; and
logic means for commanding the means for controlling the switch of each said battery module sequentially so that the switch of each said battery module is progressively closed one after the other.
2. A system according to claim 1 , wherein the means for controlling the switch of each of the battery modules varies the duty cycle of the pulse width modulation signal by a same percentage in each pulse.
3. A system according to claim 1 , wherein the means for controlling the switch of each of the battery modules varies a frequency of the pulse width modulation signal.
4. A system according to claim 1 , further comprising, for each said battery module, an additional capacitor connected in parallel to the diode and to the switch of the battery module.
5. A system according to claim 1 , wherein, for each said battery module, the switch is a MOSFET transistor, and the diode is an intrinsic diode of a MOSFET transistor.
6. A system according to claim 5 , further comprising additional means for controlling the MOSFET transistor corresponding to the diode of each said battery module using an inverse signal of that controlling each said switch.
7. A system according to claim 1 , further comprising means for adjusting inductance of the electrical connection.
8. A system according to claim 1 , wherein the means for controlling the switch of each of the battery modules uses as the pulse with modulation signal a pulse width modulation signal having a duty cycle varying between 0% and 100%, 0% and 100% being excluded.
9. An electric or hybrid powertrain automobile comprising the system according to claim 1 , the load being a powertrain of the automobile.
10. A system according to claim 1 , wherein the logic means commands the means for controlling the switch of each of the battery modules so that:
the means for controlling the switch of each of the battery modules initially commands the switch of each said battery module open, then
the means for controlling the switch of each of the battery modules commands the switch of a first battery module of the plurality of battery modules so that the duty cycle is progressively increased from 0% to 100% while the switches of the other battery modules of the plurality are kept opened, and
the means for controlling the switch of each of the battery modules commands the switch of each said battery module so that the duty cycle is progressively increased from 0% to 100% once the switch of the previous battery module has reached a duty cycle of 100% and until the switches of every battery module have reached the duty cycle of 100%.
11. A method for progressively increasing voltage at terminals of an input capacitor, of a system, the system including:
a battery including a plurality of battery modules arranged in series,
wherein each of the battery modules includes a switch, a diode, and a plurality of battery cells, the switch and the diode being arranged in series and connected to the plurality of battery cells,
wherein each said battery module includes:
a positive terminal connected between the switch and a cathode of the diode, and
a negative terminal connected to the plurality of battery cells and to an anode of the diode,
wherein the battery modules are connected in series so that the positive terminal of a last battery module of the plurality of battery modules is connected to a positive terminal of the battery, the negative terminal of the first battery module of the plurality of battery modules is connected to a negative terminal of the battery, and the modules are connected so that the positive terminal of each battery module of the plurality of battery modules is connected to the negative terminal of a next battery module of the plurality of battery modules;
the input capacitor connected directly by an electrical connection to the positive and negative terminals of the battery; and
a load connected in parallel to the input capacitor,
the method comprising:
elaborating a pulse width modulation signal having a duty cycle varying between 0% and 100% to control the switch of each of the battery modules; and
closing progressively the switch of each said battery module one after the other.
12. A method according to claim 11 , wherein the duty cycle of the pulse width modulation signal is varied by a same percentage in each pulse.
13. A method according to claim 11 , wherein a frequency of the pulse width modulation signal is varied.
14. A method according to claim 11 , further comprising adjusting inductance of the electrical connection connecting the input capacitor and the battery.
15. A method according to claim 11 , wherein the duty cycle is varied between 0% and 100%, 0% and 100% being excluded.
16. A method according to claim 11 , wherein the switch of each said battery module is initially opened, then the switch of a first module of the plurality of battery modules is controlled so that the duty cycle is progressively increased from 0% to 100% while the switches of the other battery modules of the plurality are kept opened, the switches of the plurality of battery modules are controlled so that the duty cycle is progressively increased from 0% to 100% once the switch of a previous battery module of the plurality of battery modules has reached a duty cycle of 100% and until the switch of every battery module of the plurality of battery modules has reached a duty cycle of 100%.