11 results about "Wave processes" patented technology

The application discloses a kind of flexible direct current transmission line fault transient electrical quantity determination methods, comprising: according to the circuit parameter of MMC converter station, construct MMC equivalent circuit when inter-pole short circuit;According to the transmission line parameter obtained, establish the equivalent model of two-port of direct current transmission line under complex frequency domain;According to the equivalent circuit of MMC when inter-pole short circuit and the equivalent model of two-port of direct current transmission line, obtain the expression of direct current fault transient under complex frequency domain;The expression of direct current fault transient under complex frequency domain is carried out Laplace transformation to obtain time domain response, the whole trend of transient process after fault can be given more accurately by the application.The calculation process is simple, avoids the complicated modeling simulation process in traditional simulation method.Meanwhile, it can well reflect the occurrence wave process when overhead line fails.The method can accurately express the overall development trend of the fault current flowing through the protection installation before the converter station is locked after the fault occurs, and has a positive significance for the fault current suppression and protection setting design of MMC-HVDC system.

The application discloses a construction method and system for long-period sea wave height time sequence process at a berth in a port, and the method comprises the following steps: constructing a wave propagation model; obtaining a wave spectrum process curve of a typical group of a boundary of the model based on measured or reanalyzed long-time sequence wind wave data, so as to drive the wave propagation model; obtaining wave parameters at the berth based on the driven wave propagation model, and calculating a nonlinear fitting relationship between the wave parameters at the boundary and the sea wave height at the berth; and obtaining long-time sequence wave parameters at the boundary, and obtaining the gravity wave short wave and low-frequency long wave process of the long-time sequence sea wave at the berth based on the nonlinear fitting relationship and the long-time sequence wave parameters at the boundary. The application can quickly realize the long-time sequence process of low-frequency long waves and gravity short waves at any berth in a port, provide dynamic load conditions of the berth affecting ship movement, and provide basic wave conditions for evaluating ship operation loss days.

The invention discloses a cable distribution parameter model construction and wave process analysis method, and relates to the technical field of the power industry, and the method comprises the steps: analyzing a cable structure to determine the hierarchy of the cable structure; constructing a distributed parameter model composed of unit length resistance, inductance, conductance and capacitance according to the ratio of the wavelength of the traveling wave to the length of the cable; an equation set is listed based on the Kirchhoff's law, and a transmission line partial differential equation describing the electromagnetic transmission characteristics of the cable is deduced; a refraction and reflection rule of traveling waves in a cable is analyzed, voltage and current refraction and reflection coefficients are deduced to determine traveling wave propagation behaviors, and in addition, time domain traveling wave fault distance measurement, fault distance measurement based on an improved head end reflection coefficient spectrum and insulation defect online monitoring based on active signal injection can be achieved in an extending mode. The method can eliminate the periodic distortion of the traditional frequency domain reflection spectrum, improves the fault distance measurement precision, achieves the real-time monitoring of the insulation state, and guarantees the safe and stable operation of the cable.

The application relates to the technical field of wind power, and is a short-term wind power prediction method considering wave fluctuation process division, which has the characteristics that wave fluctuation characteristics can be extracted according to wind turbine output characteristic analysis results and a wind speed-power physical conversion model, then an improved K-means clustering method for wind power prediction is proposed, and based on the classification results, an abnormal data processing model and a short-term wind power prediction model under different wave fluctuation processes are established. Simulation calculation verifies that the prediction method is scientific and reasonable, the prediction process is simple, the prediction precision is high, the physical meaning is clear, the prediction result is effective, and the practicability is high.

This invention discloses a virtual digital relay protection equipment simulation system, comprising: a fault scenario construction unit, used to simulate various faults and set the time, location, duration, and type of fault occurrence; a power system model construction unit, comprising: using a transformer model to simulate the dynamic changes of electromagnetic characteristics during fault occurrence; using a transmission line model to simulate the wave process, transient characteristics, and voltage and current distribution along the transmission line; and using a load model to simulate the dynamic changes of the load; a calculation unit, which, based on the nodal voltage method and the finite-difference time-domain algorithm, divides the power grid into discrete networks and discretizes time and space; and a full-process fault simulation unit, which simulates the entire fault occurrence process in stages. This system provides a comprehensive, accurate, and dynamic simulation environment for relay protection equipment testing and power system fault analysis, thereby improving the safety and reliability of the power system.

An extreme wind wave current coupling under floating photovoltaic power response test device, including environment simulation system, semi-submersible photovoltaic platform system, mooring system and data measurement and acquisition system. The environment simulation system simulates the coupling effect of wind, wave and flow composite load. The semi-submersible photovoltaic platform system contains photovoltaic component model constructed according to the predetermined scale ratio and the float component providing support and buoyancy for the photovoltaic component model, which can truly reflect the wind load effect of photovoltaic structure and the platform hydrodynamic response. In the data measurement and acquisition system, the cooperation of dynamic visual sensor and pressure sensor realizes the synchronous and accurate observation and measurement of the six degrees of freedom motion of the platform, the mooring tension, especially the deck wave process and the slamming load. The invention solves the problem of fine observation of traditional test in complex load simulation and extreme sea state, and provides a reliable test means for the safety design and performance evaluation of deep sea floating photovoltaic platform.

The utility model relates to the field of metal corrugated pipe processing equipment, and discloses a prestress metal corrugated pipe automatic forming machine which comprises a rack, a wave pressing structure, a forming structure and a cutting structure, the wave pressing structure, the forming structure and the cutting structure are all arranged on the upper end face of the rack, and the wave pressing structure comprises a feeding motor and a wave pressing box. The output end of the feeding motor is connected with the wave pressing box through a gear, the forming structure comprises a driving winding motor, a mounting plate, a winding main shaft, a first-stage adjuster, a second-stage adjuster and a third-stage adjuster, and the cutting structure comprises a sliding rail, a second adjusting seat, a first air cylinder, a progress adjusting seat, a second air cylinder and a cutting motor. According to the utility model, the wave pressing structure can be used for processing a wider steel belt, so that the steel belt can stably move in the wave pressing process, the stress is uniform in the process of moving from the wave pressing box to the winding main shaft, the forming stability is ensured, meanwhile, the automation degree is high, manual intervention is not needed, and the processing is efficient.

The application provides a wave process calculation method considering the corrugated aluminum sheath structure of a high-voltage cable, and the steps include: deducing the inner radius formula of the corrugated aluminum sheath of the high-voltage cable according to the geometric characteristics of the corrugated aluminum sheath; using the average geometric radius technology to equivalently convert the corrugated aluminum sheath into a uniform cylindrical shell; using a sine function to fit the corrugation of the actual corrugated aluminum sheath; solving the effective length of the equivalent uniform cylindrical shell; deducing the conductor impedance calculation approximate formula based on the effective length and the equivalent uniform cylindrical shell structure; deducing the admittance calculation formula based on the actual corrugated aluminum sheath structure of the high-voltage cable; calculating the cable wave transmission process characteristic parameters considering the corrugated aluminum sheath structure based on the above formula; and verifying the calculation results by building a low-voltage pulse verification test loop. The application is not only suitable for the distributed parameter equivalent circuit calculation of the corrugated aluminum sheath power cable of different sizes, voltage grades and lengths, but also can improve the electromagnetic transient simulation accuracy of the cable.

The invention relates to a floating photovoltaic dynamic response test device under an extreme wind wave flow coupling effect. The floating photovoltaic dynamic response test device comprises an environment simulation system, a semi-submersible photovoltaic platform system, a mooring system and a data measurement and acquisition system, the environment simulation system simulates the coupling effect of wind, wave and flow composite loads. The semi-submersible photovoltaic platform system comprises a photovoltaic module model constructed according to a predetermined scale ratio and a floating body module for providing support and buoyancy for the photovoltaic module model, and can truly reflect the wind load effect of a photovoltaic structure and the hydrodynamic response of the platform. And in the data measurement and acquisition system, a dynamic visual sensor is matched with a pressure sensor, so that synchronous and accurate observation and measurement of six-degree-of-freedom motion of the platform, mooring tension, particularly a deck wave rising process and a slamming load are realized. According to the invention, the problem of the traditional test in the aspects of complex load simulation and deck wave fine observation under extreme sea conditions is solved, and a reliable test means is provided for the safety design and performance evaluation of a deep and far sea floating photovoltaic platform.

The invention relates to a direct current power transmission system-oriented fault initial wave process analysis method and equipment. The method comprises the following steps of: calculating time delay of a propagation function minimum phase system; processing the rational fraction of the propagation function and the rational fraction of the wave impedance by adopting a discrete recursion convolution method in combination with the time delay of the minimum phase system of the propagation function to obtain a low-order dispersion equivalent voltage source recursion, and integrating into a high-order dispersion equivalent voltage source recursion of the propagation function according to a linear time-invariant system superposition theorem; a wave impedance equivalent voltage source and transmission line equivalent resistance are obtained by combining the recursion law of the RC parallel network; constructing a direct-current transmission broadband Bergeron equivalent calculation circuit; and analyzing the fault initial wave process by using a direct-current transmission broadband Bergeron equivalent calculation circuit. The method can be suitable for any sampling rate, transition resistance, fault position and fault type, and good precision is kept within 10-20 ms after disturbance occurs.

The application discloses a kind of based on decoupling matrix of DC transmission line fault characteristic analysis method, first equivalent DC transmission system is the circuit with unchangeable topological structure, using superposition principle will fault network equivalent pre-fault steady current and post-fault fault component network, deduce post-fault current wave analytical expression, based on the pole mode transformation of bipolar decoupling matrix, deduce the DC transmission line fault characteristic of the wave process scale of decoupled DC line in mode domain.The decoupling matrix and fault characteristic analysis method suitable for UHVDC transmission line proposed in the application, compared with traditional DC fault wave analysis method, considers the non-ideal transmission characteristics of wave at the boundary of converter, has higher analysis and calculation precision, has the advantages of simple and easy to operate, clear and so on, and has great popularization significance.