13 results about "Two-port network" patented technology

The invention discloses a virtual two-port-based inverter impedance remodeling and network power flow control method. The virtual two-port-based inverter impedance remodeling and network power flow control method comprises a voltage source type inverter impedance remodeling method and a voltage source type inverter network power flow control method. According to the voltage source inverter impedance remodeling method, system impedance modeling is firstly analyzed, virtual two-port network parameters are designed, then a control signal is calculated and input into an original system, and impedance remodeling is completed; the voltage source type inverter network power flow control method comprises the steps of collecting data, building a line model, calculating power flow control parameters, calculating control signals, inputting the control signals into an original system, and completing power flow control. The invention discloses a virtual two-port-based inverter impedance remodeling and network power flow control method, and aims to solve the problems that parameters of existing virtual impedance control exceed an actual engineering achievable range in a strong negative impedance scene and parameter setting is complicated and stability and robustness are insufficient in an asymmetric impedance scene. According to the technical scheme of impedance remodeling, the problem is effectively solved by processing symmetric and asymmetric systems in a differentiated mode.

This invention discloses a method for predicting gate switch oscillation in GaN-HEMT devices, belonging to the field of semiconductors and power devices. The invention trains a BPNN network model to obtain a preliminary mapping relationship between parasitic capacitance and gate-source voltage based on the BPNN algorithm model. Then, a Cascode-based two-port network function for GaN HEMT is established. The parasitic capacitance value of the GaN HEMT device under all S-parameters is obtained experimentally. This extracted parasitic capacitance value is then input into the BPNN network model as a dataset to obtain Vo. GS_m V under all S parameters DS C GS C GD The relationship between the surface and the curve is shown. Simulation results show that the standard error of the prediction method of the present invention is smaller than that of ANN and PSO, proving that the detection method for GaN-HEMT gate switch oscillation based on the BPNN algorithm model of the present invention has high prediction accuracy.

The application discloses a kind of λ / 4 stepped impedance transformation method and system.Therein, the method includes: in the impedance mismatching of partial discharge ultrahigh frequency load impedance and the characteristic impedance of partial discharge ultrahigh frequency measurement system, access λ / 4 stepped impedance transformation two-port network, the load impedance is wave impedance;According to characteristic impedance Z 0, wave impedance Z L And the characteristic impedance of two-section λ / 4 transmission line Z 1, Z 2, determine partial voltage reflection coefficient;According to the partial voltage reflection coefficient, determine total voltage reflection coefficient;According to the total voltage reflection coefficient, broaden the working frequency band of λ / 4 stepped impedance transformer.Therefore, break through the limitation of direct matching, by the progressive stepped impedance matching mode of sensor element, realize partial discharge ultrahigh frequency signal sensor element and subsequent radio frequency processing circuit good matching, thereby reduce the partial discharge ultrahigh frequency signal attenuation caused by impedance mismatching.

The invention belongs to the technical field of converter modeling and stability analysis, and particularly relates to a modeling and stability analysis method for a structure and network hybrid system. Comprising the following steps: S1, defining rotor mechanical admittance Y1GFM (s) and dynamic electrical admittance Y2GFM (s) of the network construction type converter according to a small signal model of the network construction type converter, and constructing a two-port network of the network construction type converter; s2, considering small signal disturbance of a phase-locked loop, defining rotor mechanical admittance Y1GFLs (s) and dynamic electrical admittance Y2GFLs (s) of the grid-following type converter, and constructing a two-port network of the grid-following type converter; s3, considering the influence of the power grid impedance admittance Yg (s), and determining an expression of the stability margin of the grid-following type converter; s4, establishing a three-port network in mixed connection with the network, and determining a stability criterion of the three-port network; according to the method, a more efficient and more applicable solution is provided for the stability analysis of the structure and network hybrid system, and the calculation complexity is reduced.

The invention provides an electromagnetic field simulation verification auxiliary radio frequency de-embedding method and device, and relates to the field of radio frequency de-embedding, and the method comprises the steps: constructing an overall test structure of a tested device according to a left test connection structure, a right test connection structure and the tested device; constructing a de-embedding structure according to the left side test connection structure, the right side test connection structure and the asymmetric passive device structure; solving ABCD matrixes of the left side test connection structure and the right side test connection structure based on a pre-verified passive electromagnetic field simulation environment, the asymmetric passive device structure and the de-embedding structure; generating an ABCD matrix of the overall test structure of the tested device based on the overall test structure of the tested device; and generating an ABCD matrix of the tested device and other two-port network parameters based on the ABCD matrix of the left test connection structure, the right test connection structure and the whole test structure of the tested device. According to the invention, the de-embedding network parameters of the tested device can be accurately obtained under a high-frequency condition, and the application range and the test precision of de-embedding are remarkably improved.

This invention discloses a method for correcting harmonic limits in an electrified railway traction power supply system. First, a two-port network model of harmonic propagation along the line is constructed. Then, based on the load harmonic equivalent model and differences in locomotive load capacity, voltage level, and power factor, a locomotive harmonic model is built, and all parameters are converted to the high-voltage side of the traction transformer. The harmonic voltage generated at the traction substation and the harmonic voltage generated at the grid side after the injection of harmonic current at the traction substation, as well as their ratio, are calculated. Then, based on the two-port network model of harmonic propagation along the line, the grid-side harmonic current is calculated. Finally, based on the grid-side harmonic current, the amplification factor of the grid-side output harmonic current relative to the traction substation input harmonic current is calculated, and the national standard corrected harmonic limit is calculated based on the amplification factor. This invention provides a method for correcting harmonic limits at the traction substation side, correcting the harmonic limit standard at the traction substation side of the line, and ensuring that the grid-side output harmonic current meets the national harmonic standard limits.

The invention discloses a radio frequency interconnection quality control method, device and system of a microwave circuit, and belongs to the field of electronic packaging, and the method comprises the steps: S1, determining a sampling scheme of interconnection physical mechanism characteristic quantity; s2, according to the sampling scheme, constructing a parameterized model for describing a physical structure; s3, according to the parameterized model, constructing a mapping network model from the physical structure to the electrical performance; and S4, after the mapping network model is obtained, obtaining overall microwave circuit characteristics through two-port network cascading. According to the invention, the electrical properties of physical structures with different shapes in different interconnection types can be predicted.

The application discloses a machine learning assisted modeling and synthesis method for a series feed array antenna unit. Firstly, a microstrip series feed array antenna is decomposed into three types of element units under the guidance of prior knowledge, and each element unit is regarded as a one-port or two-port network. Secondly, a machine learning algorithm is used to train S parameters and a radiation pattern of the element unit to obtain a proxy model. When the S parameters are trained, frequency is taken as a feature dimension to be added to a training set. When the radiation pattern is trained, in order to reduce training and prediction time, the real part and the imaginary part of the radiation pattern are subjected to discrete cosine transformation, and the transformed coefficients are learned. Then, the number of units of the series feed array antenna and a parameter combination are given, the S parameters and the radiation pattern of the element unit are predicted by using the proxy model, finally, the S parameter approximate value of the array is obtained by using an S parameter concatenation formula in a microwave network, and the radiation pattern of the array is approximated by using a radiation pattern synthesis formula.

The application discloses a method and device for obtaining microwave heating system parameters based on field-circuit combination. The application has the characteristics of simple modeling method, intuitive and reliable model, reasonable parameter selection, etc. On the premise of retaining certain accuracy, the numerical analysis process is simplified, the problem of excessive occupation of computer processor time and memory by numerical simulation technology can be solved, the reliability of simulation results is improved, repeated simulation and test adjustment is avoided, a large amount of manpower, material resources and financial resources are saved, work efficiency and work effect are improved. Specifically: through three-dimensional modeling of the heating system, two-port network division of the three-dimensional model, and combination of field analysis and circuit analysis, the parameters of the electromagnetic field in which the whole heated material in the microwave heating system is located can be effectively obtained. The application has the characteristics of accuracy and rapidity, the difficulty of field analysis on the heating cavity is reduced, and is more suitable for engineering application.

A method for determining the stability of a multi-voltage-level DC distribution system containing multiple DC microgrids is disclosed. The method first confirms that the equivalent admittance of each microgrid subsystem has no right-half-plane poles based on the specific control mode of the interconnecting converter and the equivalent open-loop gain of each microgrid operating independently. Second, based on the two-port network matrix of the interconnecting converter, the multi-voltage-level DC distribution system containing multiple DC microgrids is simplified to a single-bus DC system containing only the distribution bus. The stability of the entire system is then determined using the equivalent impedance ratio. Under the premise that each unit within the system can operate stably independently, the stability of the entire system is guaranteed when the equivalent open-loop gain of each microgrid operating independently and the equivalent impedance ratio on the distribution bus side both satisfy the Nyquist criterion. This invention utilizes the equivalent open-loop gain of each DC microgrid operating independently and the equivalent impedance ratio of the system on the distribution bus side to analyze the stability of a multi-voltage-level DC distribution system containing multiple DC microgrids. It has good flexibility and applicability, and can provide a reliable theoretical basis for the design of multi-voltage-level DC distribution systems.

The invention discloses a line parameter identification protection method based on a two-port network model. The method comprises the steps that an impedance parameter port characteristic equation of the two-port network model is established, and measurement results of voltage and current phasors at protection installation positions on the two sides of the two-port network model are obtained; determining two-port network impedance parameters under the internal fault and the external fault according to the network line parameters; according to the two-port network impedance parameters, constructing a unified identification parameter matrix under an internal fault and an external fault; combining the unified identification parameter matrix with the measurement results of the voltage and current phasors, establishing an impedance network multi-dimensional equation of multiple phasor points, and solving parameters to be identified; and according to the solved to-be-identified parameters and fault identification criteria, internal and external faults are discriminated, and dual-terminal protection is realized. The method has high protection sensitivity in a new energy-containing access power grid, and is high in transition resistance resistance.

The invention discloses an electric power protection system, a control method and a related product. The power protection system comprises a controller, a switch assembly and a three-phase shunt reactor, wherein the controller is configured to obtain a three-phase alternating current voltage and a three-phase alternating current; obtaining reactive power of each two-port network according to the three-phase alternating voltage and the three-phase alternating current; according to the reactive power of each two-port network, judging whether the reactor has a turn-to-turn short circuit fault or not; and under the condition that the phase reactor has the turn-to-turn short circuit fault, the switch assembly is controlled to be switched off. According to the embodiment of the invention, under the condition that the three-phase neutral point of the power protection system is not grounded, whether the reactor has the turn-to-turn short circuit fault is judged through the reactive power of the two-port network, and under the condition that the reactor of any phase has the turn-to-turn short circuit fault, the switch assembly is controlled to be switched off, so that the safety of a power grid is improved.