48results about How to "Avoid deep discharge" patented technology

A balancing method for a battery pack includes balancing battery cells near an end of discharge. A deep discharge of the battery cells can be prevented without using an overdischarge control unit. One battery cell balancing method includes: a balancing check condition determination step for determining whether or not a maximum voltage out of voltages of the battery cells is smaller than a reference voltage; a balancing start condition determination step for determining whether or not a residual capacity difference or voltage difference between the individual battery cells exceeds a reference value; a balancing time calculation step for calculating a balancing time for discharging the battery cell that exceeds the reference value; and a balancing operation step for discharging the selected battery cell when the battery cells are under charge or are at rest or when a discharge current of the battery cells is smaller than a reference current.

The invention discloses a source-network cooperation type capacitive hybrid direct-current circuit breaker suitable for an MMC direct-current power grid. The MMC direct-current power grid is provided with four converter stations MMC, and each converter station is provided with two converters; the converters of the four converter stations are connected to form a square-shaped structure through double-loop direct-current overhead lines; the two ends of each direct-current line connected with the converters are respectively provided with source-network cooperation type capacitive hybrid direct-current circuit breakers used for adaptively cooperating with a source-side active voltage regulation control strategy to jointly eliminate an isolation fault when the direct-current line breaks down. According to the method, the self-adaptive cooperation of the MMC active voltage regulation control strategy and voltages of pre-charging capacitors is utilized, so that low-voltage and zero-current breaking conditions are provided for a rapid mechanical switch branch, effective removal of a fault line can be achieved, the influence of fault current on the converter stations is reduced, bus voltage collapse is avoided, and normal operation of a non-fault line is guaranteed.

The invention discloses a brake energy storage device of an electric vehicle. The brake energy storage device comprises a hollow shaft, a left gear disk, a rack and a right gear disk which are arranged on the hollow shaft in a sleeving manner in sequence, and an outer brake disk arranged outside the left gear disk, the rack and the right gear disk in a sleeving manner, wherein a left pull rod and a right pull rod are arranged in the hollow shaft; the left pull rod is connected with a left brake handle of the electric vehicle through a steel wire; the right pull rod is connected with a right brake handle of the electric vehicle through a steel wire; the end socket on the outer ring of the rack is fixed on the left gear disk; the end socket of the inner ring of the rack is fixed on the right gear disk; the left gear disk and the right gear disk in initial states are meshed with the hollow shaft; the left gear disk is connected with the left pull rod, and the right gear disk is connected with the right pull rod; left teeth and right teeth are arranged on the inner rings of the two ends of the outer brake disk, respectively. The brake energy storage device of the electric vehicle is simple in structure, and the cost of parts is low; batch production is facilitated, and energy storage and release are stable and reliable; furthermore, the brake energy storage device is easy to operate and feasible, and is in particular applicable to brake energy storage and starting energy release of the electric vehicle.

The invention discloses a switching and protection circuit for a standby battery of a vehicle-mounted GPS (global positioning system) terminal. The switching and protection circuit comprises a charging chip, an electronic switch, a first voltage detection chip, a logic circuit and a second voltage detection chip, an external 5V power source is inputted in three ways, the first-way voltage is inputted to the first voltage detection chip and used for detecting input voltage, the first voltage detection chip inputs detection results to the logic circuit, the second-way voltage is directly inputted to the electronic switch, the third-way voltage is inputted to the charging chip and inputted to the electronic switch via a battery connected with the charging chip, and the electronic switch controls battery voltage output. Besides, the second voltage detection chip is connected with an output end of the electronic switch and used for detecting output battery voltage and sending detection results to the logic circuit, and the logic circuit is used for generating a judgment signal to control the electronic switch according to external power supply voltage detected by the first voltage detection chip and battery voltage inputted by the second voltage detection chip and is used for power supply switching of the external 5V power source and the battery and battery protection. By the switching and protection circuit, the standby battery can be switched on automatically when the terminal is mounted to be powered on, so that mounting and use are facilitated; and when the external power source of the terminal is cut off, outward discharge of the battery can be cut off automatically when the battery discharges to store voltage, so that deep discharge can be prevented, storage time of the terminal (battery) is prolonged, and service life of the battery can be prolonged.

A method of preventing deep discharge of the battery pack (1′) with series-connected cell groups (2a, 2b) by polarity reversal of an individual weakest cell (3), includes a difference measurement step which is repeated over time for detecting an event indicative of a probable reversal of polarity in which the change over time of the voltage difference between two cell groups (2a, 2b) having identical numbers of cells is checked to determine if the change in the voltage difference has exceeded an amount corresponding to a difference threshold value which reliably distinguishes a fast polarity reversal of an individual weakest cell (3) in exactly one cell group (2a, 2b) from the slow fluctuation of the voltage difference between two cell groups (2a, 2b) during an ordinary discharge characteristic curve without polarity reversal of an individual weakest cell (3); and a battery pack (1′) and a battery-powered hand-held power tool (7) with a monitoring circuit (5′) for implementing the method.

The invention provides a battery charging control method and device and an automobile. The method includes: acquiring a status parameter of a battery, and according to the status parameter, acquiring an actual relationship curve for internal resistance and number of charging-discharging times of the battery within a preset time, which is a time interval from an automobile startup moment to a preset moment; comparing the actual relationship curve and a preset relationship curve; if the actual relationship curve is not in a preset range of the preset relationship curve, updating a preset charging quantity threshold of the battery; according to the status parameter, acquiring a quantity value of the battery; comparing the quantity value of the battery to the preset charging quantity threshold; according to comparison results, determining whether or not a generator charges the battery. The battery charging control method and device has the advantages that the preset charging quantity threshold of the battery is flexibly adjusted according to the status features of the battery, deep discharging of the battery is effectively avoided, the battery is kept running in the optimal state and the service life of the battery is prolonged.

The invention discloses an electric bicycle, a control device and a method thereof. The control device comprises a cell sensor module, a PWM (Pulse Width Modulation) control module and a motor drive module, wherein the cell sensor module is used for detecting cell power; the motor drive module is used for driving a motor; and the PWM control module comprises a first voltage judging unit, an accelerate starting unit, a current-limitation judging unit, an undervoltage judging unit and a PWM set-value regulating unit. The invention has the advantages that by reducing starting current and judgingthe voltage value of the cell power, when judging that the cell voltage dropping variation is greater than a threshold value, the increased proportion of current is reduced immediately, and the voltage drops into a normal range and is finally retained on an undervoltage point. The invention ensures that the electric bicycle can continually run in a state with slightly lower current, an endurance mileage is effectively increased, and cell deep discharge is avoided so that the cell life is prolonged at the same time.

The invention relates to an anode for a galvanic cell, wherein the anode is constructed from an anode material containing a main component which releases lithium ions during a discharge process (26) of the galvanic cell, and at least one additive, wherein the at least one additive has an electrochemical potential which is higher with respect to elemental lithium than an electrochemical potential of the main component with respect to elemental lithium, the at least one additive has a charging capacity and a discharging capacity, and the charging capacity does not deviate from the discharging capacity by more than 10%, and a galvanic cell comprising this anode.

The invention discloses a DZSOC algorithm for a lithium iron phosphate battery. On the premise of fully considering the influence of load power and battery characteristics, the concept of dead zone SOC (DZSOC) is proposed for the first time, and the DZSOC algorithm provided by the invention is used to fuse at the DZSOC threshold Under the mechanism, it can effectively protect the use of the battery and avoid deep discharge, thereby prolonging the life of the battery. At the same time, the present invention also uses the improved equivalent circuit model to estimate the current state of charge NSOC, which has higher accuracy; by accurately estimating the current state of charge of the lithium iron phosphate battery, it can not only effectively prevent the battery from overcharging and overdischarging, but also Avoid permanent damage to the battery, greatly improve the life of the battery; and can greatly reduce the remaining capacity of the battery performance design, to ensure that the battery capacity is fully used.