9results about How to "Suppresses inrush current" patented technology

The invention relates to the technical field of power equipment operation and maintenance, provides a transformer excitation inrush current suppression system, integrates a plurality of links of data acquisition, prediction, simulation, analysis, optimization and the like, and aims to effectively suppress excitation inrush current generated by a transformer. The system can accurately predict the magnetizing inrush current condition by collecting the running state data of the transformer in real time. A suppression simulation model is constructed by utilizing historical data and a machine learning technology and is used for analyzing actual effects of different suppression strategies. Through optimization processing, after it is ensured that a prediction result accords with a preset suppression value, the system will automatically send execution parameters to an equipment end for implementation. In the implementation process, the system also performs compatibility detection and data timeliness adjustment so as to ensure the stability and safety of the whole power system. According to the invention, the negative influence caused by the magnetizing inrush current is obviously reduced, and the operation stability and the overall safety performance of the transformer are greatly improved.

The invention discloses a transformer excitation inrush current suppression method and device based on a fixed closing angle. The method comprises the following steps: acquiring the residual magnetic polarity of each phase of a main transformer after opening and the polarity of each phase of pre-induced magnetic flux of the transformer during closing; respectively obtaining a first interval enabling the A-phase residual magnetic polarity and the A-phase pre-induced magnetic flux polarity of the main transformer to be the same, a second interval enabling the B-phase residual magnetic polarity and the B-phase pre-induced magnetic flux polarity of the main transformer to be the same, and a third interval enabling the C-phase residual magnetic polarity and the C-phase pre-induced magnetic flux polarity of the main transformer to be the same; and obtaining a union set interval of the first interval, the second interval and the third interval, taking any point in the union set interval as a closing point, taking any one of the three phases as a reference, and confirming a voltage angle of the closing point, namely a closing angle of next closing. The scheme does not depend on the accuracy of the residual magnetism calculation value, and only needs to ensure that the polarity of the residual magnetism is correct, so that the convenience of engineering application is greatly improved.

This application discloses a method, apparatus, and electronic device for suppressing transformer inrush current. The method includes: outputting a pre-charge voltage at the first port of an inverter; acquiring the inverter's voltage signal and determining the zero-crossing point of the pre-charge voltage based on the voltage signal; determining a first closing time based on the zero-crossing point of the pre-charge voltage; determining a second closing time based on the first closing time and a target delay time; the target delay time being the time from when a closing command is issued by the inverter to when it is responded to by a relay; and issuing a closing command to the relay at the second closing time to control the relay contacts to close, thereby suppressing transformer inrush current. The method provided in this application can efficiently suppress transformer inrush current, which helps improve the stability of the energy storage inverter control system; at the same time, it eliminates the need to add additional hardware circuits or devices to the energy storage inverter control system, reducing the cost of suppressing transformer inrush current.

This invention provides an inverter device that, in a superimposed control method for suppressing inrush current flowing to the main transformer by superimposedly applying voltages from an external power source when the main power supply is turned on, can suppress inrush current from various external power sources. The inverter device generates a predetermined three-phase variable frequency voltage from a three-phase AC power source and includes: a main transformer that applies a first voltage from an external three-phase AC power source to the three-phase primary winding on the primary side and obtains a predetermined voltage from the three-phase secondary winding on the secondary side; and an inverter body comprising multiple inverter units connected to the three-phase secondary winding of the main transformer. The main transformer has a third three-phase winding on the primary side such that when the first voltage is applied to the three-phase primary winding, a second voltage lower than the first voltage is superimposedly applied to the primary side. The main transformer has connection terminals at both ends of each phase winding of the third three-phase winding.

This application provides a method for suppressing inrush current, a parallel system, electronic equipment, and a readable storage medium. The method includes: through a master-slave cooperative control mechanism, the master calculates the global closing point and broadcasts a synchronization command; the parallel system state switches from a conventional parallel operation state to a master-slave cooperative switching state; each slave performs delay compensation based on its own relay parameters; and finally, the EPS relays of multiple machines achieve synchronous closing at the peak point of the inverter output voltage, thereby suppressing the inrush current caused by the EPS port transformer and the circulating current between the inverters. This application's method breaks through the traditional parallel system's synchronous command execution mode, establishing a target synchronization and distributed triggering mode. This application ensures that all EPS relay contacts can achieve high-precision synchronous closing at the voltage peak point.

The present invention relates to a switch device with a closing resistor for suppressing transformer excitation inrush current and a method of using the switch device, comprising a closing resistor tank and a switch device tank, wherein a closing resistor unit is installed in the closing resistor tank, and two ends of the closing resistor unit are respectively connected to two bushings through a connecting bus, and a static contact assembly and a moving contact assembly are installed in the switch device tank, and the static contact assembly and the moving contact assembly are respectively connected to the two ends of the closing resistor unit, and also include an operating mechanism for driving the moving contact assembly to extend and retract to realize opening and closing, and a current transformer for detecting excitation inrush current is installed on the outside of the connecting bus, and the operating mechanism adjusts the closing speed of the moving contact and the static contact according to the size of the excitation inrush current detected by the current transformer. The switch device can not only achieve the purpose of suppressing the transformer excitation inrush current, but also accurately control the input time of the closing resistor, so as to prevent the closing resistor from causing the thermal capacity to exceed the tolerance value of the closing resistor due to too long an input time.

The invention discloses a magnetic bias suppression transformer which comprises a heat conduction plate, a first O-shaped magnetic core, a second O-shaped magnetic core and a third O-shaped magnetic core are sequentially fixed to the heat conduction plate side by side, each side column of the first O-shaped magnetic core is sleeved with a first framework, each side column of the second O-shaped magnetic core is sleeved with a second framework, each side column of the third O-shaped magnetic core is sleeved with a third framework, and the first framework and the second framework are sequentially fixed to the heat conduction plate. Secondary windings which are connected end to end are wound around each first framework and each second framework, a fourth framework is sleeved on the secondary windings wound around the second frameworks, primary windings which are connected end to end are wound around each third framework and each fourth framework, and an insulating layer is coated on the first O-shaped magnetic core, the second O-shaped magnetic core and the third O-shaped magnetic core; the linear inductors are respectively connected in series at two ends of the primary winding and the secondary winding to obtain excitation inductance, so that excitation inrush current is inhibited, the direct current magnetic bias phenomenon is improved, the assembly is convenient, and the space utilization rate is high.

The invention relates to an excitation inrush current suppression method for a large power transformer in a power supply and distribution circuit system, which is characterized in that a transfer branch for excitation, inrush current and overvoltage treatment is connected to a low-voltage winding side of a main transformer, and the branch comprises a power supply circuit, an inrush current treatment circuit and an overvoltage protection circuit. Through the transfer branch, the original direct closing of the main transformer and the generation of the magnetizing inrush current are converted into the generation of the magnetizing inrush current when the branch completes the closing and opening operation. And the main transformer is automatically magnetized, so that the burden of workers is reduced, and the intelligent degree of power supply and distribution is improved. In addition, a manual mode can be selected to magnetize the main transformer, so that a worker can conveniently carry out selective switching work according to actual conditions; when automatic magnetizing fails, workers adopt manual magnetizing, so that the purpose of switching can still be achieved.

The utility model belongs to the technical field of linkage control, and particularly discloses a high-voltage power supply system for compressor energy storage. According to the invention, through the matched use of fixed-frequency and variable-frequency adjustment of the compressor, the matching degree between the continuously changing pressure of the natural gas storage container (such as rock caves) and the fixedly configured compressor is improved, the starting and stopping times of the compressor are reduced, meanwhile, the bandwidth of the system for maintaining the air pressure is reduced, and the energy-saving property, the safety and the economical efficiency are considered; the main circuit breaker adopts a phase-controlled excitation inrush current suppressor for phase selection connection, so that the impact of excitation inrush current of a compressor transformer on a power grid can be suppressed; a secondary side transformer of a rectifier transformer in the frequency converter is connected with the magnetizing frequency converter, and the actual impact current of the frequency converter is smaller than the rated current through a pre-magnetizing mode, so that the expensive frequency converter is protected. The utility model is suitable for a 300MW compressed air energy storage power station.