A device for balancing load of a storage device including plural elements connected in series. The device includes: a DC/AC converter including an inverter and a series resonant circuit connected to the output of the inverter; plural AC/DC converters, each including an input and an output that is connected to one of the respective storage elements and selectively supplies power to the output thereof; a transformer, the main winding of which is connected to the series resonant circuit and the secondary winding of which has outputs connected to an input of a respective AC/DC converter; and a control circuit configured to control the DC/AC converter at the current source when a number of outputs supplied with power is no higher than a threshold and moreover configured to control the DC/AC converter at a constant power when the number of outputs supplied with power is greater than the threshold.

A battery management circuit and method for managing a power supply and one or more battery strings includes a current sensing circuit and a battery measurement circuit. The current sensing circuit is configured to: receive a current signal from at least one of the battery strings at a first terminal of the current sensing circuit; measure a magnitude of the current signal; and provide a current sensing signal indicative of the magnitude of the current signal at a third terminal of the current sensing circuit. The battery measurement circuit is configured to: receive a current sensing signal at a third terminal of the battery management circuit; measure one or more characteristics of the at least one of the battery strings; and provide a power supply control signal at a first terminal of the battery measurement circuit.

A system for power balance monitoring in an energy storage battery comprising a plurality of energy modules connected in a series-parallel configuration. The energy storage module comprises a plurality of cells. Each module is a three-terminal module. The three terminals comprise a positive output terminal and a negative output terminal for connecting the modules in a series string to a load and an energy sharing terminal for sharing energy between modules is other battery strings. A module power management sub-system comprising a current monitoring circuit is connected to each of the energy sharing terminals. Each module power management sub-system is in communication with a battery power management sub-system so that a weak module can be detected based on module current output. Advantageously, the module power management sub-system is not connected across the main power pathway of the module and so does not appreciably increase module impedance.

The battery monitoring chips each include a battery monitoring function section that is provided so as to correspond to a respective battery cell group and to monitor a state of each battery cell contained in the corresponding battery cell group, and a regulator that generates a drive voltage to supply to a configuration circuit of the battery monitoring function section based on power supplied from the battery. The battery monitoring chips are connected together in series to give a communication path, with an input end of the regulator electrically connected to an output end of another regulator. A microcomputer is connected to a battery monitoring chip, and is driven by a drive voltage generated by the regulator of the battery monitoring chip accompanying power consumption by each of the battery cells.

A high-voltage hierarchy hundred-megawatt level (100 MW) battery energy storage system and optimizing and control methods are provided. The system includes a multi-phase structure, of which each phase is divided into multi-story spaces from top to bottom. A battery module is provided in each story of the multi-story spaces. The battery module is connected to a DC terminal of an H-bridge converter, and each phase is cascaded by the H-bridge converter. A capacity of the single-phase energy storage apparatus of the present invention is large, and multiple phases can be connected in parallel to form a 100 MW battery energy storage power station. The power station has the advantages of simple structure, easy coordinated control, low control loop model and coupling, and optimal system stability. The control system of the present invention has fewer hierarchies, a small information transmission delay, and a rapid response speed.

A battery system includes a unit battery module, a current and coulomb measurement circuit and a master control circuit. The unit battery module stores electricity and calculates battery information of the battery set according to a system current value, a system coulomb value, a cell voltage and a cell temperature of the battery set. The current and coulomb measurement circuit is coupled to the unit battery module, generates the system current value according to the current flowing though the battery set, generates the system coulomb value by integrating the system current value, and provides the system current value and the system coulomb value to the unit battery module. The master control circuit is coupled to the unit battery module, receives the battery information from the unit battery module, generates a system battery information according to the battery information and provides the system battery information to an external device.

The invention relates to an intermediate storage facility for battery units, having a multiplicity of battery units, having an inverter and/or rectifier, a power supply system and a controller, wherein each battery unit has at least one chargeable battery cell and a battery management system for monitoring and regulating the battery cell, at least two battery units are connected electrically in series to form a battery chain, the battery chain is electrically connected to the power supply system via the inverter and/or rectifier, and the controller has a communication connection to all the battery management systems and is configured to bring about charging of the battery cell with electrical energy from the power supply system, to feed electrical energy in to the power supply system by discharging the battery cell and/or to bring about connection and/or disconnection of the battery unit to or from the inverter and/or rectifier.

A converter includes a DC split link with a positive line, a floating midpoint, and a negative DC line, a first DC capacitance arranged between the positive line and the floating midpoint, a second DC capacitance arranged between the negative line and the floating midpoint, a first resistor arranged in parallel to the first DC capacitance, a second resistor is arranged in parallel to the second DC capacitance. The first and the second resistors are configured to be engaged during a pre-charge phase of the converter.

A power distribution system for an electric aircraft includes a first electric propulsion unit comprising at least two power stages; a first battery pack electrically connected to a first power stage of the at least two power stages; a second battery pack electrically connected to a second power stage of the at least two power stages; and a control system configured to control the first battery pack, the second battery pack, the first power stage, and the second power stage to transfer power from the first battery pack to the second battery pack through the first power stage and the second power stage.

Systems and methods are described for managing charging and discharging of battery packs. In one or more aspects, a system and method are provided to minimize overcharging of battery cells of specific battery chemistries while still enabling fast charging cycles. In other aspects, a buck converter may be used to reduce a voltage of power used to charge the cells. In further aspects, a fast overcurrent protection circuit is described to address situations involving internal short circuits of a battery cell or battery pack. In yet further aspects, a bypass circuit is provided in series-connected battery packs to improve the charging of undercharged battery packs while also increasing the efficiency of the overall charging process. In other aspects, a circuit is provided that permits a controller to determine a configuration of battery packs. In yet further aspects, a system may determine a discharge current for a collection of battery packs based on each battery pack's state of health (SOH) and forward that determination to an external device.