A battery management system for dynamically balancing power in a battery module is provided. The battery management system comprises a plurality of modules, and each of the plurality of modules comprises a plurality of bricks. Each of the plurality of bricks comprises a plurality of blocks, electrically connected in one of a series configuration or a parallel configuration and a controller assembly provided in each of the plurality of the modules. The controller assembly comprises a first converter adapted to be connected to the plurality of bricks and a second converter adapted to be connected to an external system. The controller assembly is configured to obtain a plurality of battery pack parameters from the plurality of bricks using the first converter, process the obtained plurality of battery pack parameters and determine a current level to regulate a charging or discharging of the battery pack using the second converter.

A method for controlling a cell current limiting value for a battery management system. In some examples, the method includes determining quadratic reference currents of a battery cell; calculating a corresponding reference time constant for each reference current using a model for the calculation of a RMS value of a cell current by reference to a continuous current; constituting a diagram for the relationship between the reference time constant and the quadratic reference current; determining a predictive time constant by the comparison of a quadratic measured value of a cell current with the quadratic reference currents; calculating a predictive RMS limiting value of the cell current; calculating a first predictive limiting value for a short predictive time, a second predictive limiting value for a long predictive time, and a third predictive limiting value for a continuous predictive time; and calculating additional RMS limiting value for the cell current.

A method controls the current output of a battery for driving a rail vehicle. A battery actual current I.sub.bat,ist passes via a converter to an asynchronous motor, being a drive for the vehicle. The battery actual current I.sub.bat,ist is set by control circuits as a function of a feedforward control torque M.sub.ff and a specified torque M.sub.tf. The feedforward control torque M.sub.ff is calculated using a transfer function H.sub.sys(z), which maps the torque setpoint value M.sub.soll onto the battery actual current I.sub.bat,ist as follows: I.sub.bat(z) H.sub.sys(z) M.sub.soll(z). Accordingly, a zero-point z=znmp, which lies outside the unit circle, is determined by the transfer function H.sub.sys(z). The feedforward control torque M.sub.ff is calculated as follows: M.sub.ff(z) I.sub.bat,neu(z)/(H.sub.sys(z) z) where: I.sub.bat,neu(z)=I.sub.bat,ideal(z) I.sub.bat,ideal(z=znmp) where: I.sub.bat,neu[n]=I.sub.bat,ideal[n] for all n>0, so that pole point/zero point cancellation is reached by z=znmp at the battery ideal current.

The present disclosure provides a method and apparatus for controlling a voltage of an electric machine, applied to a vehicle having an electricity-generation-starting-up integrated electric machine, which relates to the technical field of vehicle controlling. The method includes: when the vehicle is in a voltage-controlling mode, acquiring a current battery voltage, a current battery electric current and an electric-current limit value of the vehicle; according to the battery voltage, determining an initial target voltage; according to a difference between the electric-current limit value and the battery electric current, determining a superposing-voltage value; based on the superposing-voltage value and the initial target voltage, determining a target controlling voltage; and based on the target controlling voltage, controlling the battery voltage of the vehicle.

A power regulation unit is provided for regulating power to or from a power tool battery pack. The power regulation unit includes power regulation circuitry and a controller. The power regulation circuitry is configured to regulate a received power. The controller is connected to the power regulation circuitry. The controller is configured to receive input power from one or more battery cells, regulate the input power by performing at least one of a voltage regulation and a current regulation, and output a regulated output power. For voltage regulation, the regulated output power includes a constant voltage regardless of an operating current of the power tool. For current regulation, the regulated output power includes a constant voltage up to a predetermined current threshold.

A current detection circuit includes a current sampling branch, a switch branch, a first current mirror branch, a capacitor branch, a feedback branch and a control branch. The control branch receives the second current and outputs the first current and the first voltage signal. The current sampling branch outputs a first discharging current. The switch branch establishes and disconnects the connection between the first current mirror branch and the capacitor branch. The capacitor branch is charged in response to the first charging current and discharged in response to the first discharging current. The first current mirror branch outputs the first charging current. The feedback branch adjusts the second charging current to adjust the first charging current, so that the total charge of the capacitor branch is balanced with the total charge of discharge within one switching cycle, so that the first current is represented by the first charging current.

An inverter parallel system and a zero feed-in control method for the inverter parallel system are provided. The system includes at least one first inverter, at least one second inverter, a load, an electrical grid, a controller, and an electrical parameter measuring device. The controller includes a system control module, and the first inverter includes an inverter control module. The system control module is configured to determine a battery power reference value of an energy storage battery according to an electrical grid current reference value and an electrical grid current sampling value. The inverter control module is configured to control the first inverter, such that a feed-in current flowing into the electrical grid side is zero, and the second inverter operates in a maximum power point tracking state. Therefore, in the system, zero feed-in control may be achieved without energy management and without communication between inverters. Therefore, the need for installation of communication lines in the conventional wired communication is eliminated, system costs and installation difficulty are reduced, and the system can operate in the optimal state.

A lithium battery system comprising a battery and a feedback current control apparatus having a first current capture device that comprises: a first feedback current capture module for capturing feedback current; a first switch module for conducting or unidirectionally cutting off a main circuit; and a control module for receiving a first voltage of one end of a driver on the main circuit, a second voltage of one end of the battery, and the temperature of the battery. When a difference between the first and second voltage is greater than a preset voltage and the temperature of the battery is less than or equal to a preset temperature, the first switch module is controlled to unidirectionally cut off the main circuit to capture feedback current by the first feedback current capture module on a first current capture circuit, greatly reducing the probability of lithium precipitation and risk of thermal runaway.

A charging system includes: a power management integrated circuit, a bidirectional voltage conversion circuit, a controller and a battery level detection circuit. The bidirectional voltage conversion circuit is configured to work in a working mode including at least a boost mode and a buck mode. The controller has a first terminal. An input terminal of the battery level detection circuit is connected to a battery, an output terminal of the battery level detection circuit is connected to the first input terminal of the controller, and the battery level detection circuit is configured to detect a voltage and a current of the battery and transmit the voltage and the current of the battery to the controller. The controller is configured to control the working mode of the bidirectional voltage conversion circuit and a working state of the power management integrated circuit according to the battery voltage and the current.

Disclosed herein are battery management systems (BMS) for controlling the operating state of a battery pack device, as well as methods for changing the operating state of a battery pack device. The battery pack may have multiple cells therein, each cell capable of generating multiple different voltages to allow more energy (voltage×current) to be quickly and efficiently put into the battery, thus optimizing battery charging (i.e., reducing battery charging times). These battery packs may change from operating in series, to operating in parallel, when desired, while utilizing affordable relays and more affordable electrical components. These battery packs may be comprised of any number of cells and can controlled and/or operated by the BMS, for optimal battery charging, or for optimal discharging, as desired. The BMS may be any type of control logic and/or software, operable to control and/or operate the battery packs.