12 results about "Overcurrent relay" patented technology

The invention relates to the technical field of locomotive line detection, in particular to a line detection system and device for a locomotive main transformer, and the system comprises a transformer which comprises an input side and an output side, the input side is used for being connected with a power supply, the output side comprises an end a and an end n, the end a is used for being connected with the end A of the main transformer, and the end n is used for being connected with the end X of the main transformer; the end a is connected with an over-current relay; the input side is connected with a conduction test loop, an operation test loop and an overload test loop; the conduction test loop is used for testing the conduction states of the main transformer, the a end and the n end; the operation test loop is used for carrying out power supply detection on the main transformer; when the transformer is in overload operation, the overcurrent relay drives the overload test loop to be conducted; therefore, through the arrangement of the conduction test loop, the operation test loop and the overload test loop, the conduction state, the power supply condition and the overload condition of the main transformer line can be rapidly detected, and cumbersome connection and disconnection operation is not needed.

The present invention discloses a detection device for repairing a medical linear accelerator, which relates to the technical field related to medical linear accelerators. An ionization chamber is used to convert an X-ray intensity signal into a current signal. Then, four groups of LED lights are used in conjunction with an undercurrent relay and an overcurrent relay. When the current intensity reaches the operating voltage range of the undercurrent relay and the overcurrent relay, the corresponding LED lights are illuminated, thereby utilizing the color differences of different LEDs to mark the X-ray intensities at different positions. At the same time, a rotating detection antenna is used to drive a large number of ionization chambers to rotate, and the visual persistence effect is used to display the X-ray irradiation trajectory and range. In this way, different light colors can be used to intuitively mark the X-ray intensities of different areas in a three-dimensional space, thereby realizing the visualization of the X-ray path and irradiation field, and facilitating on-site maintenance engineers to inspect and adjust the medical linear accelerator.

The application provides a reverse time-lag overcurrent relay protection regulation method and system, comprising: when the system resonates based on the outlet current monitoring of the APF: based on the pre-constructed optimal relay protection action table, the APF of the optimal relay protection action value is cut off; continue to monitor the outlet current of the APF, if the current harmonic content is less than the action value but the power grid quality does not meet the set power supply quality requirement, based on the power quality requirement in the micro grid, the active damping control is added in the selected APF. When the micro grid island APF parallel system operation resonates, first, the connection between the APF and the large power grid is cut off by the reverse time-lag overcurrent relay protection to suppress the inter-machine resonance, then the active damping control is added to improve the system power quality, the problem that the phase deviation exists between the LCL type APF output compensation current and the detection current is solved, the system loss is reduced, the effective suppression of the APF parallel inter-machine resonance is realized, and the power quality is improved.

The utility model discloses a control loop of an external motor cooling device, which relates to the technical field of cooling device control, and is characterized in that a main motor, a current transformer and a current relay are arranged, so that a power line of the main motor is connected with the current transformer, and the current transformer is in mutual inductance connection with the current relay; the current relay is connected in series with the cooling device, and when the current passing through the current relay reaches a set value, the auxiliary contact of the current relay is automatically closed, and the cooling device is automatically started at the same time, so that heat dissipation and temperature reduction are carried out on the main motor; the cooling device can achieve the automatic start-stop function according to the change of the load, it is ensured that the cooling device can be rapidly and effectively put into use under the large-load condition, an operator does not need to conduct on-site operation, and therefore great convenience is brought to the operator.

The application discloses a welding power supply device with short-circuit protection function, which comprises a welding box, a power supply unit, a voltage and current display, a transformer, a fuse, an overcurrent relay and a thermistor unit, the power supply unit is installed on the inner upper side of the welding box, a control panel is arranged in the welding box, the voltage and current display is connected with the control panel, a main circuit is connected outside the transformer, the fuse is arranged in the main circuit, a connecting port is arranged outside the welding box, the main circuit is connected with the connecting port through internal wiring, and the overcurrent relay is arranged in series on the main circuit; the thermistor unit is installed in parallel with the overcurrent relay on the same section of the main circuit; the welding power supply device can realize double short-circuit protection, the thermistor unit arranged in parallel on the main circuit can freely adjust the series or parallel monitoring of the variable resistance unit with different resistance values, effectively cope with the problems of instantaneous large current and overheating, and reduce the possibility of false triggering.

The utility model relates to the technical field of transformer heat dissipation, in particular to a starting control system of a container heat dissipation fan, which is applied to a battery energy storage container and comprises an electrical cabin, a power supply and a battery cabin, and a plurality of groups of heat dissipation fan components, a power supply switch and a control component are arranged in the electrical cabin; the power supply switch is electrically connected with a power supply; current detection is achieved through a current relay through a starting control circuit used for controlling starting and stopping of a cooling fan assembly, and therefore starting of the cooling fan assembly is controlled through current; when the current or the power exceeds a preset threshold value, the purpose of predicting the temperature rise is achieved, so that the cooling fan assembly is started in advance; the cooling fan assembly is started until the temperature rise caused by heat accumulation is avoided; therefore, the working state and the potential heat generation of the equipment can be predicted. And meanwhile, the fan is stopped after the heat is completely dissipated through the temperature controller.

The utility model discloses a circulation-free circuit with multiple parallel branches of a battery pack, which belongs to the technical field of batteries and comprises a battery management system (BMS) control box, a battery pack module, a switch module and a high-voltage battery (HVB) insulation detection module. The high-voltage battery (HVB) insulation detection module comprises a direct-current charging positive contactor module, a direct-current charging negative contactor module, a Hall sensor module, a battery assembly negative contactor, a current relay normally-open type, a pre-charging contactor and a pre-charging resistor, the total cathode of the battery pack module is connected with the direct current charging negative contactor module, the battery assembly negative contactor and the pre-charging contactor through the Hall sensor module; the direct current charging positive contactor module is connected with the switch module through the current relay normally-open type and Hall sensor module. Through the circulation-free circuit provided by the utility model, a current loop can be prevented from being formed among multiple branches of the battery pack when a manual service switch (MSD) of the high-voltage distribution box is inserted back.

The utility model relates to the technical field of power distribution cabinets, in particular to a power distribution cabinet capable of preventing an overcurrent fault, which comprises an overcurrent fault prevention mechanism comprising a power distribution box. According to the utility model, the interior of the power distribution cabinet is designed into a multi-layer structure through the drawing mechanism, different types of elements are placed on the bottom layer, the middle layer and the upper layer respectively, the vertical space is reasonably utilized, the problem of unreasonable internal space layout of a traditional power distribution cabinet is solved, different types of elements are installed in a layered and isolated manner, electromagnetic interference is reduced, and electrical isolation is ensured; the arrangement of the hollowed-out partition plates not only ensures the electrical isolation among the layers, but also provides a channel for ventilation and heat dissipation, effectively avoids the thermal interference of high-temperature elements on key components such as an overcurrent prevention relay and the like, improves the accuracy of overcurrent fault detection and processing, and can directly pull out the drawing mechanism during maintenance, thereby avoiding the operation in a compact space, and reducing the maintenance cost. The operation difficulty and the risk of new faults caused by misoperation are reduced, and the convenience and safety of maintenance are improved.

The invention discloses a welding power supply device with a short-circuit protection function, which comprises a welding box, a power supply unit, a voltage and current display, a transformer, a fuse, an overcurrent relay and a thermistor unit, the power supply unit is arranged on the upper side in the welding box, and a control panel is arranged in the welding box. The voltage and current display is connected with the control panel, the transformer is externally connected with a main circuit, a fuse is arranged in the main circuit, a connecting port is arranged outside the welding box, the main circuit is communicated with the connecting port through internal wiring, and an over-current relay is arranged on the main circuit in series. The thermistor unit and the over-current relay are installed on the same section of main circuit in parallel; dual short-circuit protection can be achieved, the thermistor units arranged on the main circuit in parallel can freely adjust the variable resistance units with different resistance values to conduct series or parallel monitoring, the problems of instantaneous large current and overheating are effectively solved, and the possibility of false triggering is reduced.

The application discloses a fault processing technology for a "double-high" type novel power distribution network. The method first constructs a fault database covering multiple scenes based on short-circuit calculation and a fault sample generation mechanism; then, voltage / current time series are normalized and polar coordinate mapping is performed, and Gramian Angular Summation Field (GASF) is used to convert the time series into a two-dimensional image; further, a convolutional neural network is used to extract multi-channel image features and output fault categories; finally, according to the fault categories and short-circuit current levels, the pickup current and time scale coefficient of the directional overcurrent relay are updated online, and a nonlinear optimization model is established under the condition of constraining the coordination time interval of the main and standby relays to solve the optimal relay setting value of the minimum total action time. Compared with the traditional fixed setting value scheme, the application can significantly improve the fault classification accuracy and protection action speed of the power distribution network and realize adaptive protection coordination under a complex source-network-load-storage scene.

To provide a branch-type power generation connection panel and a power system to achieve "capacity expansion" or the like by externally attaching a housing of a power generation connection panel, which incorporates a vacuum circuit breaker, to a side of a housing of a grid interconnection panel with its bottom edge higher than that of the housing of the grid interconnection panel or the like.SOLUTION: A power generation connection panel 1, which connects a power generation device P to a grid interconnection panel C and a load L, includes a branch electrical path 2 branched from a bus electrical path M and connected to the power generation device P, and a vacuum circuit breaker 3 provided in the branch electrical path 2 in a panel housing 10 thereof, the panel housing 10 is mounted externally on a side surface of a panel housing C' of the grid interconnection panel C, and the bottom end is higher than the bottom end of the panel housing C' of the grid interconnection panel C. Furthermore, the branch electrical path 2 may be arranged internally between an upper panel housing 10A and a lower panel housing 10B, and the vacuum circuit breaker 3 may be arranged within the upper panel housing 10A or the lower panel housing 10B, or a disconnector 4, current transformer 5, overcurrent relay 6, or the like may also be included. A power system 50 having the grid interconnection panel C, the load L, and the power generation device P may also include the branch electrical path 2, the vacuum circuit breaker 3, or the like.SELECTED DRAWING: Figure 1

The utility model belongs to the technical field of floor heating pipeline monitoring, and aims to solve the problem that pipeline water leakage cannot be warned in time. The floor heating water leakage protection device comprises a controller, a pressure sensor, a relay, a contactor, an electromagnetic valve and a buzzer. The signal input end of the controller is connected with a pressure sensor arranged at a floor heating pipeline, and the output end of the controller is connected with a relay, an electromagnetic valve and a buzzer; a normally open contact of an overcurrent relay KA1 in the relay and a coil of a contactor KM1 in the contactor are connected in series and are connected to a three-phase power supply to form a first loop; a normally open contact of the contactor KM1 is connected in series with an indicating lamp HG1 and is connected to a three-phase power supply to form a first indicating loop; a normally open contact of an overcurrent relay KA2 in the relay and a coil of a contactor KM2 in the contactor are connected in series and are connected to the three-phase power supply to form a second loop. The device can realize water leakage and pressure early warning.