38 results about "HVDC converter" patented technology

A dynamic frequency coordination control method for asynchronous regional power grids during wet and dry seasons is provided. By using frequency synchronous control in VSC-HVDC, frequency consistency and synchronization between the sending-end and receiving-end grids can be ensured within the range of power adjustment, enabling real-time and automatic sharing of frequency regulation resources between the two grids. Through the use of bilateral frequency limiting control in LCC-HVDC, the frequency regulation effect is enhanced, balancing frequency fluctuations between the sending-end and receiving-end grids. VSC-HVDC adaptive reactive power support control is employed to provide reactive power support to nearby LCC-HVDC, avoiding frequent operations of LCC-HVDC converter transformers and filters during frequency limiting control actions, thereby extending equipment lifespan. Furthermore, by utilizing grid-following and grid-forming control in renewable energy grid integration with additional frequency control, the frequency support capacity of renewable energy generation is improved.

This invention discloses a method and system for reconstructing the full waveform of port voltage of power equipment based on transient radiated electric field signals. This method reconstructs the average voltage across the equipment based on the transient radiated near-electric field generated when the high-voltage direct current (HVDC) power equipment operates, obtaining a fitted full waveform of the port voltage. This can be used for non-contact online monitoring, fault diagnosis, and situational awareness of HVDC power equipment. This invention effectively overcomes the shortcomings of traditional methods for calculating electromagnetic radiation interference in converter stations, such as high computational resource consumption and low simulation efficiency. The monitoring method based on electric field sensors overcomes the disadvantages of traditional voltage measurement devices, such as large size, high cost, and high maintenance difficulty. This invention enriches the means of online monitoring of power equipment in HVDC converter valve halls and improves the maintenance efficiency of DC systems.

The invention belongs to the field of modular multi-level converters, and discloses a valve tower pressurization test method and system for a flexible direct current transmission converter valve, sub-modules are paired and electrified and pressurized at the same time to form a mutual communication test environment, and a function test process at least comprises a cross communication test between two sub-modules; flexibly selecting whether to update the two sub-module programs in the group in batches before testing or not according to an instruction; and the process reliability is guaranteed through a fault interruption and instruction skipping mechanism. By adopting the method, the test period is remarkably shortened, the manpower consumption is reduced, and the problems that the traditional test process is tedious and the safety is low are effectively solved; the program batch updating function gets rid of the power grid charging limitation and has engineering practicability; and the sub-module function test is synchronously completed, so that the test efficiency, the operation safety and the function completeness are comprehensively improved.

The invention discloses a flexible DC converter valve circulating current active control method and a related device, the circulating current of a flexible DC converter valve is controlled by a pre-designed peak value of a bridge arm current, a reference value of a circulating current controller does not need to be calculated in advance, and control can be accurately carried out through closed-loop control according to the pre-designed peak value of the bridge arm current; the added loop and calculation amount are small, engineering implementation is easy, and the problems that in an existing flexible direct-current converter valve bridge arm circulation control method, a reference value of a circulation controller is a pre-calculated value and cannot adapt to the scene that system parameters can deviate according to different operation working conditions, errors exist in a calculation result, and the reliability is poor are solved. And more computing resources are occupied.

The invention discloses an intermediate frequency sea wind flexible direct current converter valve control method and system based on hot spot migration trajectory prediction, and the method comprises the steps: carrying out the intermediate frequency carrier phase alignment of converter valve operation data, obtaining the fusion data of phase alignment, and obtaining a chip or submodule loss sequence; obtaining a reduced-order thermal model parameter, and constructing a reduced-order coupling predictor based on the phase-aligned fusion data and the chip or submodule loss sequence; according to the reduced-order coupling predictor, obtaining a hotspot migration trajectory prediction and trajectory uncertainty elliptic domain; and according to the hot spot migration trajectory prediction and trajectory uncertainty elliptic domain, solving a thermal-electric cooperative control target, obtaining a gate pole control instruction, and controlling a converter valve. According to the method, the prediction precision is improved through online self-calibration of the model, and active equalization of thermal-electric cooperation is realized by using the uncertainty boundary.

A HVDC transformer configuration for use in electrical power transmission to at least a first AC network and a second AC network. The configuration including a three single phase HVDC transformer, in which each phase includes a first winding connected to a HVDC converter(s) and a second winding connected to both the first AC network and the second AC network; and wherein the second winding of each phase is configured as an auto-transformer and includes a tap connection, the tap connection being connected to a Phase Shifting Transformer to regulate the power transmission to the second AC network.

The energy storage type flexible direct current converter comprises an upper bridge arm, a lower bridge arm, an alternating current output end and a direct current output end, the upper end of the upper bridge arm is connected with the positive electrode of the direct current output end, and the lower end of the upper bridge arm, the upper end of the lower bridge arm and an external alternating current power grid or equipment are connected with the alternating current output end. The lower end of the lower bridge arm is connected with the negative electrode of the DC output end, one electrode of the DC output end is grounded, and the other electrode is connected with an external DC power grid or equipment. When the negative electrode of the direct current output end is grounded, the upper bridge arm is connected with the full-bridge sub-module and the bridge arm reactor in series, and the lower bridge arm is connected with the bridge arm reactor, the full-bridge sub-module and the energy storage sub-module in series; when the positive electrode of the direct current output end is grounded, the upper bridge arm is connected with the energy storage sub-module, the full-bridge sub-module and the bridge arm reactor in series, and the lower bridge arm is connected with the bridge arm reactor and the full-bridge sub-module in series. According to the method, the overhead line power transmission channel suitable for large-scale new energy can be constructed, and fluctuation of new energy output can be effectively stabilized.

This invention proposes a high-voltage direct current (HVDC) converter and its accelerated commutation method. It involves modifying each arm of an existing conventional HVDC converter by adding arm-coupled reactors or replacing existing anode reactors with arm-coupled reactors. The implementation is very simple, straightforward, and low-cost. The beneficial effects of this invention are: by configuring arm-coupled reactors with a certain value, the commutation process is accelerated, the commutation overlap angle is reduced, thereby expanding the operating range of the HVDC converter, increasing the transmittable power, and reducing power loss; it can even rely on the commutation voltage created by the arm-coupled reactors to perform voltage compensation when the AC voltage unexpectedly drops, thereby suppressing commutation failure. In HVDC transmission applications, this invention exhibits excellent economic efficiency and reliability, enhancing its contribution to the national economy.

The application discloses a kind of flexible direct current converter valve destructive test method, device, equipment and medium, first, according to the long-term current-carrying capacity of IGBT device in flexible direct current converter valve submodule, IGBT test product submodule is constructed;It includes IGBT test product submodule with long-term current-carrying capacity and IGBT test product submodule without long-term current-carrying capacity;Second, the two test product submodules are respectively subjected to up and down IGBT straight-through destructive test, the test product submodule with long-term current-carrying capacity is subjected to bypass switch miscombination destructive test, and the two test product submodules are respectively subjected to bypass switch refusal destructive test;Finally, the explosion-proof performance of the flexible direct current converter valve is judged according to the test phenomenon of the above test, and the test result is obtained.The application can better meet the needs of flexible direct current converter valve destructive test and improve the reliability of test result.

The invention belongs to the technical field of electric power equipment assembly and detection, and discloses an automatic assembly and detection system based on a flexible direct current converter valve module. A cleanliness control assembly; tightening the cooperation assembly; a detection recognition unit; a data fusion and twinborn center; an error evaluation and risk comprehensive evaluation unit; and a scheduling and feedback system. According to the invention, a real-time acquisition and control mechanism is introduced into an assembly executing mechanism, and stress judgment and sequence adjustment are combined, so that the tightening force of the fastener is dynamically adjusted, and different from the operation depending on artificial experience or fixed torque in the prior art, the operation is more accurate. According to the scheme, the pre-tightening force deviation and the local stress concentration position can be automatically recognized in the tightening process, the tightening sequence is adjusted in real time, in this way, the fatigue damage caused by excessive tightening and the loosening problem caused by insufficient tightening are effectively avoided, and the assembly consistency and the structural stability of the valve module are remarkably improved.

The invention relates to a converter valve cooling water system corrosion and scaling combined simulation test method and device. The method comprises the following steps: building a closed circulation loop; raising the water temperature to 24-26 DEG C by using a tubular heater; adjusting the concentration and conductivity of scaling ions in a closed circulation loop to realize an acid-base environment for accelerated simulation of the scaling process, and adjusting the concentration of aluminum ions in initial circulating water to 2.5 mg.L <-1 > when the conductivity is adjusted to be lower than 0.5 mu S.cm <-1 >; applying a high-voltage direct-current voltage, and establishing an electric field through a voltage-sharing electrode; continuously operating for at least 336 hours, and regularly detecting water quality parameters through the sampling measurement pool; and after the test is finished, taking out the voltage-sharing electrode, analyzing the scaling morphology and components on the surface of the voltage-sharing electrode, and evaluating the scaling characteristics under different water quality conditions. Compared with the prior art, the device has the advantages of accurately simulating the multi-field coupling operation environment of the water cooling system in the flexible direct current converter valve, realizing accurate analysis of the scaling characteristics of the converter valve and the like.

The invention relates to the technical field of direct current transmission, and discloses a surplus power self-absorption flexible direct current converter and a direct current sending-out system.The flexible direct current converter comprises a plurality of phase units, and the phase units comprise a power self-absorption phase unit and a plurality of basic phase units; an upper bridge arm and a lower bridge arm of the power self-absorption phase unit respectively comprise a plurality of cascaded power absorption sub-modules, an upper bridge arm and a lower bridge arm of the basic phase unit respectively comprise a plurality of cascaded half-bridge sub-modules, and each power absorption sub-module comprises a half-bridge circuit and a power absorption circuit connected with the half-bridge circuit. The power consumption circuit comprises a switching circuit and an energy dissipation resistor. A large number of full-control type power devices do not need to be configured, the construction cost can be greatly reduced, the area of a converter station is saved, and the number of the added devices is minimum on the premise that the operation function of an original converter is not affected with extremely low cost.

This provides improvements to DC voltage controllers in power transmission networks using SGFM. [Solution] A method is provided which is carried out by a DC voltage controller for an HVDC converter, comprising: generating a synchronous angular velocity and a synchronous phase angle based on a DC voltage error signal; determining an AC grid phase angle from a composite signal, the composite signal being based on a function of the AC grid signal and the synchronous angular velocity; and generating a phase angle requirement for the HVDC converter, the phase angle requirement being based on the AC grid phase angle and the synchronous phase angle.

This invention belongs to the field of converter and its control technology, specifically relating to a combined active-commutation HVDC converter and its control method, aiming to solve the problems of large size and heavy weight of filter elements in existing active-commutation HVDC converters. The invention includes: N active-commutation converters, N corresponding transformers, three-phase filter capacitors and three-phase filter inductors on the AC side, and filter inductors on the DC side. By controlling the switching time and conduction time of the turn-off devices inside each active-commutation converter, three-phase grid current control can be achieved. This invention effectively avoids the risk of commutation failure in traditional technologies, and the three-level square wave currents of different phases output from the grid-side transformer windings can be superimposed to form a multi-level stepped wave current, which outputs high-power-quality AC current to the grid side after passing through the AC-side filter network. Furthermore, by controlling each active-commutation converter, the active and reactive power on the grid side can be decoupled.

The invention relates to the technical field of supports, and particularly discloses an anti-inclination support for mounting a pole-mounted direct current converter transformer, the anti-inclination support comprises four mounting support rods, and the inner sides of the upper ends of the four mounting support rods are jointly provided with a transformer body; mounting plates are arranged on the inner sides of the left mounting supporting rod and the right mounting supporting rod correspondingly, and symmetrical mounting vertical plates are fixedly mounted on the upper end faces of the mounting plates correspondingly. A worm wheel can be driven to rotate under the effect of a worm, a connecting rotating shaft can drive a limiting support block to rotate in the rotating process of the worm wheel, and then the side edge, the upper edge and the lower edge of a transformer body can be supported under the effect of the limiting support block. And the transformer body can be limited and protected, and therefore it is guaranteed that the transformer body does not incline.

A method performed by a DC voltage controller for a HVDC converter, including generating a synchronous angular speed and synchronous phase angle based on a DC voltage error signal; determining an AC grid phase angle from a combination signal, wherein the combination signal is based on an AC grid signal and a function of the synchronous angular speed; generating, for the HVDC converter, a phase angle demand, wherein the phase angle demand is based on the AC grid phase angle and the synchronous phase angle.

The present application relates to the technical field of power conversion control, and particularly relates to a HVDC converter bias current anti-disturbance suppression method, system and medium, the method comprising: collecting an AC side current signal of the HVDC converter, and determining a bias current representation quantity for representing a bias current state; according to a coupling relationship between the bias current representation quantity and a current control process, equivalent the bias current representation quantity to a bias disturbance quantity; constructing an extended state observation object based on the AC side current signal and the bias disturbance quantity, and obtaining a state observation result by observation; generating an anti-disturbance compensation quantity according to the state observation result, and adaptively correcting the anti-disturbance compensation quantity according to the bias current representation quantity; and applying the corrected anti-disturbance compensation quantity to a modulation control quantity to suppress the bias current. Through the present application, the problem that the bias current disturbance caused by the bias current cannot be accurately represented and dynamically compensated in the current control process of the existing HVDC converter, resulting in insufficient bias current suppression effect, is effectively solved.

The invention provides a valve tower clear distance insulation design method and system for a flexible direct current converter valve, and the method comprises the steps: carrying out the discharge test of a gap between valve layers, a gap between valve towers and the ground, and a gap between valve towers, and obtaining test data; analyzing a discharge rule based on the test data to obtain a function relationship between the valve tower clear distance and the voltage; and calculating the valve tower clear distance based on the voltage value of the flexible direct current converter valve in combination with the function relationship between the valve tower clear distance and the voltage. According to the method, the function relationship between the valve tower clear distance and the voltage is studied by carrying out the discharge test on the gap between the valve layers, the gap to the ground of the valve tower and the gap between the valve towers, a quantitative basis can be provided for engineering practice, accurate optimization of the air clear distance is achieved on the premise that the safety insulation margin is guaranteed, and the reliability and economical efficiency of equipment are balanced.

The present invention provides a method for suppressing converter commutation failure, a coupling voltage circuit, and a converter. The method comprises: when an AC voltage drop occurs during the converter commutation process, applying an induced voltage to the bridge arm of the converter to compensate for the AC voltage and thereby facilitate commutation completion. The method, coupling voltage circuit, and converter of the present invention are capable of suppressing high-voltage direct current (HVDC) commutation failure. To address the commutation failure problem existing in existing HVDC converters, the use of the converter of the present invention can improve the converter's ability to resist commutation failure, thereby reducing the number of commutation failures and improving the safety and stability of power grid operation.

The application discloses a high-speed protection method suitable for a wind-solar-storage power source collection line, first analyzes a discharge circuit of a filter capacitor of a wind-solar-storage power source converter and a capacitor of a flexible direct current (HVDC) converter sub-module from the perspective of capacitor discharge, analyzes and obtains a fault characteristic difference of the wind-solar-storage power source and the HVDC converter in an initial fault stage; according to the fault characteristic difference of the wind-solar-storage power source and the HVDC converter in the initial fault stage, uses a time-frequency energy coefficient to measure a fault characteristic difference of short-circuit currents on both sides of the line; according to an amplitude error existing in currents on both sides of the line in normal operation, combines the time-frequency energy coefficient, and proposes a protection action criterion suitable for high-speed protection of the wind-solar-storage power source collection line, so that high-speed protection of the wind-solar-storage power source collection line is realized. The method proves a time-frequency characteristic difference of the HVDC converter and the wind-solar-storage power source, when a fault occurs in the collection line, the protection can rapidly and reliably act within 5 ms, and has strong resistance to transition resistance and system noise.

The invention discloses a power supply system control method and a power supply system, and relates to the technical field of power supply systems, and the method comprises the steps: responding to a low-voltage operation instruction of a vehicle, and controlling a battery circuit breaking unit to be closed, so that the vehicle is in a low-voltage operation state; in the low-voltage operation state, the high-voltage direct-current converter is controlled to be closed; and if it is detected that the second load has the power supply demand, controlling the low-voltage DC converter to be turned on to supply power to the second load. According to the control method, the low-voltage direct-current converter is directly connected to the battery, so that the battery circuit breaking unit can be controlled to stop running when the vehicle has no power requirement. At the moment, if it is detected that the second load has a power supply demand, the low-voltage direct-current converter can be directly controlled to operate, so that electric energy is provided for the second load, the battery circuit breaking unit and the high-voltage direct-current converter do not need to operate, and extra electric energy loss caused by operation of the battery circuit breaking unit and the high-voltage direct-current converter can be avoided; and the waste of electric energy is avoided.

The embodiment of the present application provides a power supply system, an electrical system assembly and a vehicle, which adopts a high-voltage direct-current converter, a first power distribution device and a battery assembly to form a low-voltage primary main power grid, adopts the high-voltage direct-current converter, a second power distribution device and the battery assembly to form a low-voltage primary auxiliary power grid. Two low-voltage primary power grids are provided with only one power supply with a voltage value of a first voltage value. The first power distribution port is used to supply power to a power consumption device with a working voltage of the first voltage value. The first direct-current voltage converter arranged in the first power distribution device and the second direct-current voltage converter arranged in the second power distribution device are used to output direct-current with a second voltage value, so as to form two low-voltage secondary power grids. Therefore, in the power supply system with two power sources, a low-voltage primary power grid corresponding to the second voltage value and a redundant power supply device associated with the primary power grid do not need to be additionally increased.

A method (100) for controlling a high voltage direct current, HVDC, converter arrangement (1) is provided. The HVDC converter arrangement comprises an upper converter (11) connected between a positive DC pole (21) and an ungrounded common neutral bus (20) and a lower converter (12) connected between a negative DC pole (22) and the ungrounded common neutral bus. The method comprises the steps of: determining (110) a DC voltage difference between a first DC voltage (Upositive) across the upper converter and a second DC voltage (Unegative) across the lower converter; and adjusting (120) the DC voltage (U neutral) at the non-grounded common neutral bus to reduce the DC voltage difference.

The present application relates to a kind of high-frequency signal injection-based flexible direct current converter transformer interturn protection method, electronic equipment and medium.The method is superimposed high-frequency detection modulation wave on fundamental modulation wave by control system, so that converter applies high-frequency detection voltage to converter transformer valve side;Corresponding electrical response is collected, and high-frequency response component corresponding to injection frequency is extracted, fault characteristic quantity is constructed, which is compared with preset setting condition, to determine interturn fault and output protection action signal.The present application does not need to add special primary injection equipment, and can improve the sensitivity and timeliness of slight interturn fault identification.

The application relates to the technical field of flexible direct current power transmission, in particular to a low self-inductance capacitor for a flexible direct current converter valve. The application provides a low self-inductance capacitor which comprises a first element strip, a second element strip, a first busbar and a second busbar, the first element strip comprises a first conductive strip, a second conductive strip and a plurality of first elements, the second element strip comprises a third conductive strip, a fourth conductive strip and a plurality of second elements, the first busbar and the second busbar are arranged on the same side or different sides of the first element strip and the second element strip along a first direction; along the winding axis direction of the first element or the second element, the first conductive strip is closer to the third conductive strip than the fourth conductive strip, the first conductive strip and the third conductive strip have the same polarity and are connected with the first busbar, the second conductive strip and the fourth conductive strip have the same polarity and are connected with the second busbar, and the second busbar is provided with a first connecting end which is located between the second conductive strip and the fourth conductive strip.

A method for controlling or operating a high voltage direct current (HVDC) converter within a multi-terminal HVDC system, a multi-terminal HVDC system, a controller, and computer software implementing such control. The output of the HVDC converters is controlled by providing a respective or converter-specific DC voltage reference for each HVDC converter. A feedback signal is determined for each HVDC converter, and the converter-specific feedback signal includes a modification to the DC voltage reference of the respective converter. Determining the converter-specific feedback signal includes analyzing a terminal characteristic of each converter and determining an indicator indicative of a balance loss margin, or modeling the terminal characteristic of each converter as an equivalent circuit based on or representing a response of the HVDC converter to its voltage reference modification in a given operating state. The HVDC converter terminal characteristics may include impedance, voltage droop, power, branch current, node voltage, and the like.

The invention relates to a power distribution device (2) of a vehicle, in particular a fuel cell vehicle, comprising at least one high-voltage direct current converter unit (4) which is electrically connected or connectable on the input side to at least one fuel cell unit (14) and on the output side to at least one high-voltage consumer (6), comprising at least one high-voltage to low-voltage converter unit (8) which is electrically connected or connectable on the output side to a low-voltage consumer (10), and comprising at least one housing (12) in which the high-voltage direct current converter unit (4) and the high-voltage to low-voltage converter unit (8) are arranged.

The application discloses a kind of train high-low voltage terminal component intelligent detection circuit scheme, it is related to train instrument intelligent detection field, mainly realize the intelligent detection of AC network voltage table, auxiliary voltage table, train DC network voltage table, high voltage DC converter.The application simulates the input voltage of train DC network voltage table, AC network voltage table, auxiliary voltage table, high voltage DC converter using programmable controller PLC, touch screen and switching power supply, compare the voltage of simulation table on touch screen with the voltage shown by measured train DC network voltage table, AC network voltage table, auxiliary voltage table, realize fault judgment by calculating whether the difference between them is within the required range;The output voltage of high voltage DC converter is fed back to programmable controller PLC, and the difference is calculated by comparing the reference voltage and the feedback voltage conversion value by programmable controller PLC, and whether it is within the required range is judged, and whether it is "fault" or "normal" is displayed on touch screen, to realize intelligent detection.

The invention relates to a controllable commutation high-voltage direct-current power transmission converter fault detection method and system, and the method comprises the steps: collecting the visible light, infrared light and acoustic data of a controllable commutation high-voltage direct-current power transmission converter, and obtaining the visible light characteristics and infrared light characteristics based on the visible light data and infrared light data, global spatial domain features and local spatial domain features are extracted based on the visible light features and the infrared light features, and frequency feature extraction is performed by using wavelet transform based on acoustic data; fusing the global spatial domain feature and the local spatial domain feature to obtain a first fusion feature, and fusing the frequency feature and the first fusion feature to obtain a second fusion feature; and carrying out controllable commutation high-voltage direct-current power transmission converter fault detection based on the second fusion feature. The system is used for realizing the method. Compared with the prior art, the method can accurately distinguish the environmental noise and the fault signal, and enables the fault detection result to be more accurate.

The invention discloses an HVDC converter valve short-circuit fault positioning method and system based on a fault segment. The method comprises the steps of obtaining a valve short-circuit protection action condition of a high-voltage direct-current power transmission system; when the valve short circuit protection action condition is protection action, the waveform segment length between the sudden change moment and the protection action moment is calculated, and a fault waveform segment is called according to the waveform segment length; based on the data between the sudden change moment and the protection action moment, a simulation waveform fragment data set is constructed, and the simulation waveform fragment data set comprises multiple sets of simulation waveform fragments; respectively calculating a comprehensive dynamic time planning distance between the fault waveform fragment and each group of simulation waveform fragments, obtaining a minimum comprehensive dynamic time planning distance, and defining a distance threshold value; values smaller than a distance threshold value are screened out from all the comprehensive dynamic time planning distances, and simulation fault positions corresponding to the values serve as actual fault positions. According to the method, the most accurate current converter short-circuit fault positioning can be realized under the condition of not additionally installing a measuring point.