A circuit for controlling a voltage, including: a plurality of traction battery banks; a first switch K1, where a first terminal of the first switch K1 is connected to each of the plurality of traction battery banks; a drive circuit, where the drive circuit includes a three-phase inverter and a three-phase motor, where a midpoint of each of three-phase bridge arms of the three-phase inverter is connected to each of three-phase coils of the three-phase motor respectively, where a first busbar terminal is connected to a positive electrode of each of the plurality of traction battery banks and a positive electrode of a charging port, a second busbar terminal is connected to a negative electrode of each of the plurality of traction battery banks and a negative electrode of the charging port, and where the three-phase motor is connected to a second terminal of the first switch K1.

A power storage device includes a plurality of batteries connected in series, a cell balancing circuit configured to individually discharge the plurality of the batteries, and a controller configured to execute a cell balancing process in which operation of the cell balancing circuit is controlled so that at least one of cell balancing target batteries is discharged by a predetermined state of charge, the at least one of the cell balancing target batteries including the battery that is fully charged.

Various technologies and embodiments are presented to operate a two-phase machine. The two-phase machine is powered by a first phase circuit comprising a first string of battery cell devices electrically coupled to the machine via a first supply line and a first return line, and a second phase circuit comprising a second string of battery cell devices electrically coupled to the machine via a second supply line and a second return line. One or more processors can be configured to control operation of one or more switches in the first and second strings of battery cell devices, such that a first voltage provided by the first string of battery cell devices is 90 out of phase relative to a second voltage provided by the second string of battery cell devices. The two-phase machine can be a motor comprising a stator with a two-phase winding pattern.

A system and method are provided for controlling charging and discharging of a group of batteries connected in parallel. A battery charging/discharging control system includes a first battery group comprising one or more first batteries connected in parallel, a second battery group connected in parallel with the first battery group and comprising one or more second batteries connected in parallel, and a charging/discharging controller to generate a first current pulse and a second current pulse, different from the first current pulse. The charging/discharging controller supplies the first current pulse and the second current pulse to the first battery group and the second battery group to control charging/discharging.

The power supply device performs one-side charge control for controlling the system main relay, the charging relay, the series connection relay, the parallel connection relay, and the first and second neutral point relays so that only the first power storage unit is charged using the external DC power until the voltage of the first power storage unit becomes equal to or higher than the voltage of the second power storage unit before the first and second neutral point relays are turned on and the power storage device is charged using the external DC power.

An example of an apparatus to connect to a utility-scale power distribution network is provided. The apparatus includes a first energy storage unit to store a first amount of energy at a utility-scale to be provided to a power distribution network. Also, the apparatus includes a first inverter to connect the first energy storage unit to the power distribution network. The apparatus further includes a second energy storage unit to store a second amount of energy at the utility-scale to be provided to the power distribution network. The apparatus also includes a second inverter to connect the second energy storage unit to the power distribution network. Furthermore, the apparatus includes a switch disposed between the first energy storage unit and the second energy storage unit, wherein the switch converts the first energy storage unit and the second energy storage unit between a line interactive state and an online state.

Example methods to manage a plurality of battery packs of an electric vehicle include initiating a charging process for a primary battery pack and an auxiliary battery pack, determining that an Open Circuit Voltage (OCV) of the primary battery pack matches an OCV of the auxiliary battery pack, and based on determining that the OCV of the primary battery pack matches the OCV of the auxiliary battery, connecting the primary and auxiliary battery packs in parallel and initiating parallel charging of the primary battery pack and the auxiliary battery pack.

A power backup system includes a multi phased energy storage and a backup supply. The energy storage includes battery strings, each capable of supplying either an AC or DC voltage to a load. During normal operation, the backup supply is configured for being supplied with an AC voltage from a utility grid and being connectable to a DC voltage supplying battery string of the energy storage. During abnormal operation, the backup supply is configured for, in a first period of time, being supplied from a DC output voltage established by the a first battery string and after expiration of the first period of time being supplied from the AC output voltage established by a second battery string.

A reconfigurable battery system is disclosed. The reconfigurable battery system comprises a reconfigurable battery cell array, a controller, and a bus switch. The battery cell array is configured to operate in a first discharge mode, a second discharge mode, or a charge mode. The battery cell array includes a plurality of battery cells arranged as at least a first column of battery cells between a second battery terminal and a first battery terminal and a switch between each battery cell within the first column of battery cells. The bus switch is in signal communication with the battery cell array at the first battery terminal and is configured to select between electrically connecting the first battery terminal to a normal voltage bus or a high-voltage bus.

Embodiments that provide advanced charging of energy source arrangements for energy storage applications are disclosed. The embodiments can be used within energy storage systems having a cascaded arrangement of converter modules. The embodiments can include the application of pulses to an energy source of each module of the system. The pulses can be applied for a duration sufficient to initiate an electrochemical reaction. Feedback based pulse control embodiments are also disclosed.