4results about How to "Limit short circuit current" patented technology

The utility model discloses a high impedance dry type transformer with short circuit protection, comprising a cabinet and a three-phase dry type high impedance transformer arranged in the cabinet, one side of the three-phase dry type high impedance transformer is provided with a breaker input short circuit protection switch, the cabinet wall of the cabinet is provided with a temperature controller and a breaker, and the cabinet wall of the cabinet is provided with a short circuit protection switch. The temperature controller is provided with an overtemperature trip switch, the overtemperature trip switch of the temperature controller is electrically connected with the circuit breaker, and the circuit breaker input short circuit protection switch is electrically connected with the temperature controller and the circuit breaker respectively. According to the three-phase dry-type high-impedance transformer, high-impedance design is combined with the dry-type transformer, so that the impedance of the dry-type transformer is increased, short-circuit current can be limited, impact on a system is reduced, safety and environmental protection performance are improved, and a circuit breaker input short-circuit protection switch is arranged on one side of the three-phase dry-type high-impedance transformer, so that the safety of the dry-type transformer is improved. And over-current and short-circuit protection of the transformer can be realized by combining the temperature controller and the short-circuiting device, the response speed is high, and the protection effect is good.

The application discloses a parallel fault-tolerant type converter bus short-circuit current limiting method and system, and relates to the technical field of wind power generation. The application establishes a differential equation of wind power generation voltage under normal state, obtains periodic components and non-periodic components of the differential equation when a short-circuit fault occurs in a converter of wind power generation, calculates the relationship between the periodic components and normal current before the fault through the reactive power characteristics when the converter is short-circuited, obtains a result expression of the periodic components, introduces virtual resistance and virtual inductance, orients the reference voltage of the converter, and calculates the virtual resistance and virtual inductance values meeting the requirement of reactive current injection based on the reference voltage, d-axis and q-axis components of the converter current. The application can effectively limit the short-circuit current of the converter bus, and can take corresponding protection measures when a short-circuit fault occurs in the converter of wind power generation, thereby protecting the converter and other devices in wind power generation.

This application provides a safety coating and electrode sheet for battery electrode sheets, belonging to the field of new energy battery technology. The safety coating is a composite layer structure, comprising: a barrier layer disposed on a current collector, the impedance of which increases stepwise with increasing potential difference at its location; and a thermally fused insulating layer disposed on the barrier layer, the impedance of which increases stepwise with increasing temperature. The barrier layer and the thermally fused insulating layer function synergistically, providing a bidirectional response mechanism for voltage and temperature. This safety coating for battery electrode sheets, through the synergistic effect of the barrier layer and the thermally fused insulating layer, can ensure the stability and performance of the battery during normal operation. In the event of internal short circuits or other faults, it responds rapidly and forms an effective insulating barrier, cutting off current and preventing safety accidents such as battery thermal runaway, thus providing reliable safety assurance for battery use.

The application discloses a grid-forming inverter virtual impedance control method, device and equipment, and the method comprises the following steps: acquiring an external voltage signal and an external current signal of an output inductance branch of a grid-forming inverter; based on the external voltage signal, the external current signal and power reference information of the grid-forming inverter, an instantaneous value reference signal of a target internal potential of the grid-forming inverter is obtained through a preset grid-forming control algorithm without virtual impedance; based on the instantaneous value reference signal of the target internal potential, the external voltage signal, the external current signal, preset virtual impedance parameters and preset real impedance parameter estimation values, a phase voltage instantaneous value reference signal of an equivalent controlled voltage source on an alternating current side of a power module of the grid-forming inverter is obtained through a virtual impedance construction algorithm; and a pulse width modulation signal is generated according to the phase voltage instantaneous value reference signal of the equivalent controlled voltage source, and the pulse width modulation signal is used to drive the power module of the grid-forming inverter, so that the virtual impedance control precision is improved.