15results about How to "Prevent overcurrent" patented technology

The invention discloses a VSG-based low-voltage ride-through hybrid control method for a network-building converter. The method comprises the following steps: acquiring grid-connected point voltage and output current of a grid-forming converter in real time, and judging whether to enter a low-voltage ride-through state according to a grid voltage drop degree; in the initial stage of a fault, a current reference saturation mode is adopted to quickly limit the output current of the converter so as to prevent a power device from being damaged by overcurrent; in the fault duration stage, a dynamic self-adaptive virtual impedance and reactive power reference coordinated regulation mechanism is introduced, so that the converter gradually recovers the reactive power injection capability while limiting the fault current, thereby realizing effective support for the grid-connected point voltage; when the voltage of the power grid drops seriously, the capacity of the inverter can be reserved for the reactive power support by temporarily reducing the output of the active power. According to the method, the current protection and voltage support requirements during the fault period are considered, and the operation stability and the power grid adaptive capacity of the grid-forming converter in the low voltage ride-through process are improved.

This utility model discloses a charger with a storage battery, which includes a charger body and a mounting housing. The storage battery is installed in the lower part of the mounting housing, a battery management unit is installed on the upper part of the storage battery, and a charging control unit is installed on the upper part of the battery management unit. An input connector is installed at the front end of the mounting housing, and an output unit is installed at the rear end of the mounting housing. By switching the control module and the charging control unit in coordination, bidirectional energy management between the external power supply and the storage battery can be realized. When the external power supply is connected, it can directly power the electronic product and charge the storage battery simultaneously. When the power is off, it automatically switches to power supply from the storage battery. It can also charge the storage battery independently. It has the characteristics of uninterrupted power supply, dual-path operation and multi-path energy management. Combined with a safety protection module, it prevents overcharging, over-discharging, overcurrent and short circuit, improving the applicability and safety of the device in outdoor, emergency and mobile scenarios.

The invention relates to a motor drive control method for preventing battery overcurrent of a new energy automobile, which comprises the following steps of: distinguishing a battery recharging mode and a battery discharging mode according to an automobile state; when the motor is in a battery recharging mode, the maximum allowable kinetic energy feedback torque of the motor is calculated; when the motor is in the battery discharge mode, calculating the maximum allowable discharge driving torque of the motor; carrying out filtering processing on the calculated torque value, and calculating an output torque value; the motor can be effectively controlled only by monitoring the current state of the battery, the overcurrent of the battery can be prevented, and the design cost can be reduced.

The invention relates to the technical field of electric vehicles, and discloses a low-temperature slow charging control method for a pure electric vehicle, which comprises the following steps of: in response to a low-temperature slow charging starting signal, acquiring the current charge state and the current temperature of a battery by a battery management system; if the current charge state is lower than a preset charge threshold value and the current temperature is lower than a preset temperature threshold value, the battery management system sends a maximum allowable discharge power limit value to the vehicle control unit; and the vehicle control unit receives the maximum allowable discharge power limit value, and limits the initial operation power of the battery heating device based on the maximum allowable discharge power limit value, so that the power extracted from the battery by the battery heating device does not exceed the maximum allowable discharge power limit value. According to the invention, power flow among the vehicle control unit, the battery management system, the vehicle-mounted charger and the heater can be managed cooperatively, and over-current and over-discharge faults of the battery are strictly avoided while the low-temperature heating requirement is guaranteed.

The application discloses a PFC-LLC resonant switching power supply, which comprises a PFC circuit and an LLC circuit, an input end of the PFC circuit is connected with an AC input interface, an output end of the PFC circuit is connected with an input end of the LLC circuit through a high-voltage bus, an output end of the LLC circuit is connected with a DC output interface, and the PFC-LLC resonant switching power supply further comprises a bus voltage sampling circuit, a fault detection circuit, a first enabling control circuit and a second enabling control circuit, an input end of the first enabling control circuit is connected with an output end of the fault detection circuit, an output end of the first enabling control circuit is connected with a voltage sampling end of a PFC control unit of the PFC circuit, a first input end of the second enabling control circuit is connected with the output end of the fault detection circuit, an output end of the second enabling control circuit is connected with a voltage feedback input end of an LLC control unit of the LLC circuit, an input end of the bus voltage sampling circuit is connected with the input end of the LLC circuit, and an output end of the bus voltage sampling circuit is connected with the voltage feedback input end of the LLC control unit.

The invention provides a micro-nano satellite multi-constraint fine control method based on actuator dynamics, and belongs to the field of spacecraft control, and the method comprises the steps: considering the electromechanical characteristics of a reaction wheel, and building a micro-nano satellite attitude deep coupling model containing the dynamic characteristics of the reaction wheel; aiming at reaction wheel axle friction and counter electromotive force interference, designing a double-interference observer to accurately estimate the reaction wheel axle friction and counter electromotive force interference; designing a nonlinear state-dependent obstacle function to convert a constraint state into a tracking control variable according to the star rotating speed and reaction wheel current physical constraint; and a composite controller is constructed by combining a double-interference observer and a nonlinear state-dependent barrier function, and the design of the high-precision controller of the micro-nano satellite is completed. According to the method, the problem of various physical constraints in micro-nano satellite control can be solved, the interference of the reaction wheel is compensated, and the method has the characteristics of high reliability and high accuracy.

The invention relates to the technical field of Vienna rectifiers, in particular to a control method for improving harmonic power grid input adaptability of a Vienna rectifier, which comprises the following steps of: performing coordinate transformation on acquired three-phase power grid voltage and input current to obtain voltage and current signals under a fundamental wave rotating coordinate system, extracting a fundamental wave current error signal, and calculating the harmonic power grid input adaptability of the Vienna rectifier; the method comprises the following steps: acquiring a current error component of each harmonic, converting the current error component into a rotating coordinate system corresponding to each specified harmonic to obtain the current error component of each harmonic, and in each harmonic rotating coordinate system, independently controlling the current error component of the corresponding harmonic by adopting a proportional-integral controller to generate a control voltage component of each harmonic; inversely transforming the control voltage component of each harmonic to a fundamental wave rotating coordinate system, and superposing to form a total harmonic compensation voltage; according to the invention, by adopting the control method of combining the self-adaptive loop parameters with the bus lifting strategy, the adaptability of the input current of the rectifier along with the power grid voltage under the harmonic power grid voltage is enhanced, so that the problem of overcurrent of the rectifier under different working conditions is avoided.

This invention relates to the field of energy storage system control technology, and discloses an adaptive dynamic reconfiguration integrated control method and device for energy storage systems. This invention achieves pooled management of physical energy storage resources by constructing a virtual energy management platform at the software layer. It combines task performance constraints and multi-objective optimization to achieve dynamic configuration of virtual energy storage units. Through the conversion of logical topology to physical action commands, coupled with a safe topology reconfiguration strategy, it realizes autonomous and online reconfiguration of the electrical connections and operating modes of the energy storage system. Simultaneously, relying on closed-loop adaptive adjustment of comprehensive deviation values, it achieves real-time optimization of the system's operating status, effectively solving the problem of refined management of heterogeneous resources, meeting the grid's demand for rapid and seamless multi-task switching, significantly improving the flexibility, intelligence level, and operating economy of the energy storage system, and adapting to the complex operating requirements of high-proportion renewable energy power systems.

The invention relates to the field of medical care equipment, and discloses a portable electronic cold compress device which comprises a cold compress device shell, a cold compress device cover plate is arranged on the front side of the cold compress device shell, two sets of mounting blocks are arranged on each of the left side and the right side of the cold compress device shell, and binding belts are arranged on the sides, away from each other, of the two sets of mounting blocks. Connecting hook-and-loop fasteners are arranged on the outer sides of the four binding belts, a flexible protection layer is arranged on the front surface of the cold compress device cover plate, fixing plates are arranged on the sides, close to each other, of the four binding belts, and T-shaped movable inserting blocks are arranged on the sides, close to each other, of the four fixing plates. And movable mounting grooves matched with the mounting blocks are formed in the sides, far away from each other, of the four groups of mounting blocks. Through closed-loop control of the temperature sensing module and the main control module, accurate adjustment of the temperature of the cover plate of the cold compress device is achieved, the cold compress temperature is stably maintained in a target range set by a user, and controllability and consistency of the treatment effect are guaranteed.

This invention proposes a six-axis robot operation control method, device, six-axis robot, and storage medium, relating to the field of robot control technology. The method employs a decoupled hybrid interpolation strategy when the end effector is detected to be traversing a singular region. This strategy involves independently planning the joint motions affecting the posture and combining them with position interpolation. This avoids the joint overspeed, overcurrent, and motion loss-of-control problems caused by traditional pose-based joint interpolation methods near singular points. While ensuring the end effector always moves strictly along the target straight trajectory, it reasonably sacrifices minor posture deviations, improving the robot's motion stability and system robustness when traversing singular regions. This enables continuous and controllable output of joint commands, thereby ensuring equipment safety and process quality, and has significant engineering application value.

The invention relates to a DC transformer topology. The DC transformer topology comprises an inductor, a first side energy storage module comprising a plurality of first energy storage units connected in sequence, a second side energy storage module comprising a plurality of second energy storage units connected in sequence, a switch module comprising a plurality of switch devices connected in sequence, and a first change-over switch. Wherein at least the switching device located at the first position is a bidirectional switch, and the energy storage unit at least comprises one resonance unit. One end of the inductor is connected with a low-voltage side power supply anode, and the other end is connected with the first energy storage unit and the first change-over switch; the other end of the first change-over switch is connected with the first second energy storage unit and the negative electrode of the power supply. The first end of the first switching device is connected with the change-over switch, the second ends of the odd-numbered switching devices are connected with the second energy storage unit, and the second ends of the even-numbered switching devices are connected with the first energy storage unit; and the second end of the last energy storage unit is a high-voltage end. The direct-current transformer adopting the topology is higher in stability.

The application discloses a kind of energy scheduling methods based on dynamic impedance, comprising the following steps: S1: real-time acquisition and each inverter in parallel system corresponding grid each phase sequence dynamic impedance;S2: according to each inverter in parallel system corresponding grid each phase sequence dynamic impedance, the safe limit of each inverter in parallel system each phase charge-discharge power is calculated;S3: according to the safe limit of each inverter in parallel system each phase charge-discharge power calculated, adjustment target power distribution.The energy scheduling method based on dynamic impedance proposed in the application can avoid overcurrent problem caused by circulating current, and plays a role in protecting inverter.

This invention discloses an active injection-type fault nature identification method for wind farms connected to the grid via flexible DC transmission lines, belonging to the field of power system relay protection technology. S1. After a fault occurs, the sending-end MMC converter station detects a change in the circuit breaker state, exits the original V-f control strategy, and sets the modulation wave to zero, causing power loss on the AC side of the sending-end MMC converter station; S2. After waiting for the fault arc extinction time, the circuit breaker is reclosed, establishing a current injection channel; S3. The sending-end MMC converter station outputs a three-phase symmetrical sinusoidal modulation wave, which is processed to generate a switching signal, activating the capacitors of each phase bridge arm submodule, injecting a voltage detection signal into the AC side of the faulty line; S4. Based on the difference in the amplitude of the current signal generated by the voltage detection signal, the fault nature of the line is identified. This invention can accurately identify the fault nature of wind farms connected to the grid via flexible DC transmission lines, shorten power restoration time, improve system operational reliability, avoid overcurrent during the identification process in the event of severe faults, and has high sensitivity to high-resistance faults.

The application provides a CLLC resonant converter soft-start device and method, which comprises a primary side and a secondary side coupled through a transformer, the primary side comprises a first H-bridge; the secondary side comprises a second H-bridge, the opposite switch tubes S1 and S4, S3 and S2 on the first H-bridge are pulsed with the same pulse respectively, and the upper and lower switch tubes on the same bridge arm are alternately conducted; the second H-bridge is uncontrolled rectification, and no driving signal is applied on the corresponding switch tube; the duty cycles of the pulse signal and the complementary pulse signal on the first H-bridge are asymmetrically changed; the pulse signal is the pulse through the switch tube S1 and the switch tube S4; the second pulse is the pulse through the switch tube S3 and the switch tube S2; the current overcurrent during starting is inhibited, the purpose of smoothly establishing the output voltage is achieved, the ZVS opening characteristic is achieved, and the ZCS closing of half of the diodes on the rectification side is always ensured, and the high-frequency oscillation of the resonant current caused by the participation of the parasitic capacitor in the resonance can be avoided.

This invention relates to the field of roof-mounted lift tent technology and discloses a bed board extension structure based on a roof-mounted lift tent. The structure includes a base, a canopy mounted on the base, a sliding support drive between the canopy and the base, a flip-up bed board mounted on the side of the base, and locking components and fixing linkages mounted on the canopy and base. The cross-support rod assembly of this invention, relying on the dynamic changes in structural form during the lifting process, achieves a dual improvement in support stability and load-bearing capacity, exhibiting significant force advantages. When not raised, the structure is easily compressible. As the canopy rises, the sliding end of the supporting rod gradually moves towards the center and becomes increasingly vertical, reducing the vertical angle and increasing the lateral angle. This allows the triangular support frame structure to form an efficient axial force characteristic, significantly weakening the bending moment effect and improving compression resistance. After reaching the highest position, the structure, combining its geometric shape and the central arrangement of the sliding end, forms a naturally stable structure that can effectively resist longitudinal pressure and lateral off-center loads.