62results about How to "Realize crossing" patented technology

The invention relates to a network communication area and discloses a method for penetrating the NAT. The method mainly includes: step S1: the communication terminal after the NAT device interacts with the NAT device to get the public network address and/or port behind the NAT from the NAT; step S2: the communication terminal fills the private network address and/or port information of the packet net payload as the public network address and/or port, and send the packets to the NAT device. The invention discloses the corresponding communication terminal and NAT device to support the implementation of the above method. Compared with the existing technology, the invention does not require NAT device to support the ALG (application layer gateway) and need not realize the STUN (UDP simple penetration mode of NAT) protocol, so it eliminates the limit of the static manual configuration.

The invention discloses a power line carrier-based LED visible light communication system, comprising an uplink and a downlink. The downlink comprises a PC transmitting terminal, wherein the PC transmitting terminal accesses an electric power grid via a power line PLC modulator, a power line PLC modulator is connected with the electric power grid and is connected to an FPGA encoder, and the FPGA encoder is connected to a an LED light-emitting device; and a plurality of terminal devices, wherein each terminal device is connected to an FPGA encoder, the FPGA encoder is connected with a signal processing module, and the signal processing module is connected with a photodetector. Optical signals emitted by the an LED light-emitting device is converted to electrical signals by the photodetector, the electrical signals are then amplified and processed by the signal processing module to be recovered into signalsidentical with signals modulated by the PC transmitting terminal, and at last the signals are transmitted to the terminal devices via the FPGA encoder. The uplink is configured to be symmetrical to the downlink, so as to achieve a full-duplex communication.

The invention provides a direct current monopole grounding fault ride-through method for a multi-port flexible high-voltage direct current power transmission system. The fault ride-through method is realized through coordination matching between an MMC (modular multilevel converter) based on low-resistance grounding and having negative electric level output capability and a mechanical direct current isolation switch; in a fault period, by regulating common-mode component of a reference voltage of each MMC bridge arm, fault transient state overvoltage can be eliminated under the premise of not sacrificing the controllability of the converter; meanwhile, by overlaying a fault pole bridge arm reference voltage with a first reference voltage signal and by controlling a fault pole bridge arm current to be zero, the mechanical direct current isolation switch can isolate direct current fault in a zero current condition, so that foundation is laid for the application of the mechanical direct current isolation switch in the multi-port flexible direct current power transmission system; and in the fault period, the MMC forms a loop through sound direct current bus-alternating current side low-impedance grounding pole-ground, so that transmission of half rated active power can be maintained.

The invention discloses a non-flux observation doubly-fed induction generator low voltage ride-through control method and a system, which can be applied to excitation control on a rotor-side converter of the doubly-fed induction generator in the case of deep power grid fault. The specific implementation method comprises steps: once deep fault is detected to happen to the power grid, rotor current of the doubly-fed induction generator is instantly controlled to directly track stator current at a certain ratio, and a certain compensation term related to stator voltage is injected to a rotor current instruction for providing dynamic reactive support. The invention also provides a control system structure diagram for realizing the above principle. Compared with de-excitation control, flux tracking and other low voltage ride-through excitation control methods, no flux observation step is needed for generating a transient control instruction, the structure is simple, multiple control objectives such as electromagnetic torque ripple suppression or dynamic reactive power compensation can be realized, and the low voltage ride-through ability of the doubly-fed induction generator is greatly enhanced.

The invention discloses an SIP call-based traversal network address translation method and an SIP call-based traversal network address translation. The method comprises the following steps that: a private network user performs the SIP call, and signalling proxy equipment, to which the private network user belongs, performs application layer SIP protocol analysis of an SIP message, judges whether media channel information of the application layer SIP protocol of the SIP message is needed to be modified or not according to the analyzed result, if so, modifies the media channel information into media addresses and ports which are distributed by the network and perform communication with opposite terminal network elements on media proxy equipment, and sends the modified message; and the private network user establishes media connections with an opposite terminal user through the media addresses and the ports. Through the method and the system, the SIP call-based NAT traversal is realized, without upgrading terminals and NAT equipment and increasing the loads of the NAT equipment.

The invention discloses a low voltage crossing method of a DC outward transmission system of a large-scale photovoltaic power station. When an AC power grid has different types of faults, the whole system has problems such as grid-connected current distortion and DC bus overvoltage in a basic voltage current double closed-loop control strategy and cannot realize low voltage crossing. Under the condition, a novel low-votlage control method combining a dynamic switching control method of a photovoltaic power generation module MPPT mode with current converter positive and negative sequence doublecurrent loop control of VSC of an optimized DDSRF-PLL (Decoupling Dual Synchronous Reference Frame based Phase-Locked Loop) is provided. Via coordination of a front-stage photovoltaic power station and a back-stage VSC current converter, influence from overvoltage and a negative sequence component of the DC bus to grid-connected current is suppressed efficiently. Low-voltage crossing operation ofthe large-scale photovoltaic power station is realized successfully and the capacity of stable operation of a large-scale photovoltaic power station accessing system is greatly improved.

The invention is used to realize the transparent transmission of layer-two IPv6 message in IPv4 network so as to realize the IPv6 message to cross over IPv4 network.

The invention provides a method for realizing NAT traversal. When an NAT device determines that a received control message sent by a first network device in a private network to a second network device in a public network is a specified control message based on a GAT-1400 protocol, a first private network IP address and a first port number in a URL carried by the control message are acquired; NAT(Network Address Translation) is performed on a second private network IP address serving as a source IP address of the control message according to an NAT strategy to obtain a public network IP address, and the public network IP address is taken as a target IP address for converting the first private network IP address; a port number range is searched for an unoccupied idle port number corresponding to the public network IP address to serve as a target port number for converting the first port number; and the first private network IP address is converted into the target IP address, the firstport number is converted into the target port number, and the converted control message is sent to the second network device in a public network.

The apparatus comprises: FA (foreign agent) device, MB (mobile bridge) device, and HA (home agent) device. The method thereof comprises: the FA device establishes and maintains the layer two mobile binding, and sends a registration message carrying the 802 MAC address of MB device to HA device; according to the received registration message carrying the 802 MAC address of the MB device, said HA makes a layer two mobile binding for the MB device; by learning the MAC address, getting the 802 MAC address of MH; making a layer two mobile binding for the MH.

The invention discloses an NAT crossing system of a conference TV, which comprises a communication control module and a plurality of conference terminals, wherein at least one of a plurality of conference terminals is located in an inner network, a plurality of conference terminals are connected with internet through a Router and an IP address obtaining unit, and the communication control module is connected with a plurality of conference terminals mutually through the internet. The NAT crossing system also comprises a gatekeeper which is connected with the internet, wherein the gatekeeper comprises an IP address analytical element which is used to analyze an outer network IP address corresponding to a registration request signal according to the registration request signal which is sent by the conference terminals in the inner network to the gate keeper. The invention also discloses an NAT crossing method of the conference TV. The system and the method can conveniently realize NAT crossing between the inner network and the outer network under the condition that the cost is not increased, and the system and the method are widely applied in various enterprise TV conferences.

The invention discloses an anthraquinone general formula compound and application thereof. The general formula compound is shown in a formula (1) in the specification, and in the formula (1), n is aninteger of 1-2; when n is 2, two L groups in the formula (1) can be different, and two Ar groups in the formula (1) can be different; X1-X8 are independently selected from C, CR or N, when any one ortwo of X1-X8 represent C, the C atom is connected with L, and R is selected from a hydrogen atom, alkyl of C1-C10, substituted or unsubstituted C6-C30 aryl, or substituted or unsubstituted C3-C30 heteroaryl; the Ar is selected from substituted or unsubstituted C6-C30 aryl, or substituted or unsubstituted C3-C30 heteroaryl; and the L is selected from single bonds, substituted or unsubstituted C6-C20 arylidene, or substituted or unsubstituted C3-C20 heterocyclic arylidene. The compound shows excellent device performance and stability when serving as a main body material in a light-emitting layerof an organic light-emitting device (OLED), and meanwhile the OLED adopting the general formula compound is within the scope of right protection.

The invention provides a DC voltage transformation subunit and a DC transformer comprising the DC voltage transformation subunit. The DC voltage transformation subunit comprises a fault isolation voltage equalization module and a DC/DC converter, wherein a high-voltage side of the fault isolation voltage equalization module is connected with a high-voltage direct-current bus, a low-voltage side ofthe DC/DC converter is connected with a low-voltage DC bus, the mass and the occupied area are small, cost is low, a DC transformer of the DC voltage transformation subunit comprises a plurality of DC voltage transformation subunits. The DC voltage transformation subunit is advantaged in that high-voltage sides of a plurality of DC voltage transformation subunits are connected in series, withstand voltage class requirements are met, low-voltage sides of the multiple DC voltage transformation subunits are connected in parallel, the high-power requirement is met, the number of layers of the DCvoltage transformation subunits is greatly reduced, the occupied area is reduced, cost is saved, different application scenes of one-way power flowing and two-way power flowing can be met, and automatic isolation and crossing of faults on the high-voltage side can be achieved.

The invention provides a browser-based file transmission processing method and a browser. The method comprises the steps of acquiring the file identifier of a to-be-transmitted file, reading the content of the to-be-transmitted file from the first byte of the file according to the byte order thereof, and uploading the file identifier-contained content of the file to a server in the HTTP POST manner. Since the network information is acquired by users from the server generally based on the HTTP protocol, the transmission of data packets based on the HTTP protocol is allowed by all kinds of firewalls. Therefore, in the embodiments of the invention, files are uploaded to the server by the browser based on the HTTP protocol instead of the FTP protocol in the prior art, so that the firewall traversal of uploaded files to the server from the internal network is realized. In this way, the communication security of the internal network is ensured, and the flexibility of the communication service is improved at the same time.

The invention discloses a simulation operation support system, and aims to solve the problems that an existing simulation operation support system is large in wide-area interconnection difficulty, large in repeated simulation experiment workload and large in cross-language and cross-platform difficulty. The system comprises a federation management module, a declaration management module, an extended object management module, a time management module, an ownership management module and a data distribution management module. Modules of the system are communicated by WebService service, object management is expanded, LRC entity-level management is achieved, two data interaction technologies of WebService and MQ are adopted, the applicability of the system to the simulation scale and the simulation form is achieved, and configurable distributed operation structure design is achieved by configuration documents of the system.

The invention relates to a wave power generation system low voltage ride through coordination control method, which is used for coordinating and controlling a network side controller, a machine side controller and a super capacitor energy storage device according to the power of each link during a fault period. The method comprises the following steps that the network side controller adopts voltage outer loop and current inner loop control based on power grid voltage orientation; when a low-voltage fault occurs in a power grid, a machine side controller works in a rotor energy storage mode, and a rotor rotating speed reference value is obtained by a direct-current bus voltage outer ring; when the machine side controller works in a rotor limit rotating speed mode, the rotor rotating speed reference value is set as a rotating speed limit value; the super capacitor energy storage device is controlled by a power outer ring and a current inner ring, the power outer ring is used for maintaining power balance at two ends of the direct-current bus, and the current inner ring is used for realizing rapid tracking control; and therefore, the machine side controller, the network side controller and the super capacitor energy storage device have different operation states under different conditions.

The invention relates to a packing case accessory and particularly discloses a base plate used in a handling packing case. The base plate used in the handling packing case comprises a plate body and is characterized in that the size of the plate body is the same as that of the inner diameter of the packing case, and four corners of the plate body are provided with perforations which are mutually symmetrical. The base plate is simple in structure, convenient in packing, low in production cost, large in packing quantity, and applicable to long-distance transportation for preventing handling collision, and effectively guarantees the product quality, thus being suitable for wide popularization and application.