Method and apparatus for uniform battery system state of charge management

A method of generating inverted electrical signals, comprising:

• connecting a plurality of individual batteries together in series into a first string of individual batteries;
• connecting half-bridge circuits in parallel to each of the plurality of individual batteries, each half-bridge circuit having an upper switch and a lower switch;
• connecting a first H-bridge circuit in parallel with the first string of individual batteries;
• generating a plurality of triangle wave signals at a given amplitude and carrier frequency, each being phase-shifted from the other;
• generating a modulation signal for each half-bridge circuit;
• comparing an instantaneous magnitude of a respective individual triangle wave signal to an instantaneous magnitude of a respective modulation signal;
• outputting a first command to the upper switch of a respective half-bridge circuit if the respective comparison is positive, and a second command to the upper switch of a respective half-bridge circuit if the respective comparison is negative;
• determining a respective modulation index for each individual battery based on each respective modulation signal and on the respective individual triangle wave signal;
• and
• regulating an amount of power charged to and discharged from each individual battery by controlling each respective modulation index for each half-bridge circuit, which includes controlling the respective modulation signal with respect to the respective individual triangle wave signal for each individual battery, each modulation index based on a state-of-charge (SOC) of each individual and respective battery.

A non-transitory computer-readable medium tangibly embodying computer-executable instructions of a program being executable by a hardware processor of a computing device with a user interface to provide operations to:

• generate a plurality of triangle wave signals at a given amplitude and carrier frequency, each being phase-shifted from the other;
• generate a modulation signal for each of a plurality of half-bridge circuits;
• compare an instantaneous magnitude of a respective individual triangle wave signal to an instantaneous magnitude of a respective modulation signal;
• output a first command to an upper switch of a half-bridge circuit if the comparison is positive, and a second command to the upper switch of a half-bridge circuit if the comparison is negative;
• determine a respective modulation index for individual batteries of a plurality of batteries based on a magnitude of each respective modulation signal and based on a magnitude of the respective individual triangle wave signal;
• and
• regulates an amount of power charged to and discharged from each individual battery by controlling each respective modulation index for each half-bridge circuit, and by controlling the respective modulation signal with respect to the respective individual triangle wave signal for each individual battery, each modulation index based on a state-of-charge (SOC) of each individual and respective battery;
• wherein the plurality of individual batteries are connected together in series into a first string of individual batteries, and the half-bridge circuits are connected in parallel to each of the plurality of individual batteries, each half-bridge circuit having the upper switch and a lower switch, and a first H-bridge circuit is connected in parallel with the first string of individual batteries.