18 results about "Doubly fed induction machine" patented technology

The invention relates to a doubly-fed variable-speed pumped storage unit fractional order PID additional frequency control method and system, and the method comprises the steps: building an electrical mathematical model of a doubly-fed induction motor based on a synchronous rotating coordinate system, enabling a stator flux linkage to be aligned with the d-axis direction through employing a stator flux linkage directional control strategy, and enabling the stator flux linkage to be aligned with the d-axis direction; therefore, decoupling adjustment of active power and reactive power output by the unit is realized. The frequency deviation between the power grid common connection point frequency and the rated frequency is obtained and serves as an input signal of the fractional order PID additional controller, the frequency deviation can be effectively restrained under various working conditions, the system stability and the inertia supporting capacity are enhanced, and the method is suitable for auxiliary frequency control of a variable speed pumped storage unit in a high-proportion new energy power grid.

The invention discloses an AC excitation system no-load voltage buildup and pre-synchronization grid-connected control method and system, and the method comprises the steps: obtaining the amplitude and phase of a power grid voltage in real time through a phase-locked loop when the rotating speed of a doubly-fed induction motor reaches a synchronous rotating speed range; detecting the mechanical position of the rotor by using an encoder and calculating a slip angle; carrying out fundamental component extraction and phase correction on the stator side no-load voltage; setting a stator voltage target value based on power grid voltage directional control and calculating target rotor current; constructing a rotor current inner loop control loop, calculating a feedforward decoupling item and performing phase compensation; superposing a stator voltage outer loop control loop, and correcting the rotor current through closed-loop adjustment to eliminate the deviation between the stator side no-load voltage and the power grid voltage; and when a preset synchronization condition is satisfied, closing the grid-connected circuit breaker and switching a control mode. Accurate no-load voltage buildup and smooth pre-synchronization grid connection of the excitation system are achieved through a double closed-loop control structure, and the stability and reliability of the grid connection process are improved.

The invention discloses a doubly-fed induction motor parameter identification method based on adaptive extended Kalman filtering, and aims to solve the problems of low doubly-fed induction motor parameter identification precision and integrity, sensitive noise and the like in the prior art. According to a dq-axis flux linkage equation and a voltage equation of the doubly-fed induction motor, a state space model with dq-axis current of a stator and a rotor as state variables is built, the dimension of the state space model is expanded, the full-parameter observability of resistance Rs and Rr and inductance Ls, Lr and Lm of the motor is judged by utilizing a self-adaptive extended Kalman filtering theory and combining a rank criterion, and the accuracy and accuracy of the state space model are improved. All-parameter identification of inductance and resistance of the motor is realized, and the robustness of the system is improved through a method of adaptively adjusting noise covariance. The parameter coupling influence can be effectively eliminated, and the identification precision is improved; the self-adaptive noise suppression mechanism enhances the anti-interference capability, and meets the dynamic on-line parameter identification requirements of the doubly-fed motor.

This invention discloses a method and system for no-load voltage build-up and pre-synchronization grid connection control of an AC excitation system. The method includes: acquiring the amplitude and phase of the grid voltage in real time via a phase-locked loop when the speed of the doubly-fed induction motor reaches the synchronous speed range; detecting the rotor mechanical position and calculating the slip angle using an encoder; extracting the fundamental component and correcting the phase of the stator-side no-load voltage; setting a target value for the stator voltage based on grid voltage-oriented control and calculating the target rotor current; constructing an inner-loop control loop for the rotor current, calculating the feedforward decoupling term and performing phase compensation; superimposing an outer-loop control loop for the stator voltage, and correcting the rotor current through closed-loop adjustment to eliminate the deviation between the stator-side no-load voltage and the grid voltage; and closing the grid connection circuit breaker and switching the control mode when the preset synchronization conditions are met. The dual-closed-loop control structure achieves precise no-load voltage build-up and smooth pre-synchronization grid connection of the excitation system, improving the stability and reliability of the grid connection process.

The present invention discloses a method for parameter identification of a doubly-fed induction motor based on an adaptive extended Kalman filter, which addresses the problems of low accuracy and integrity, noise sensitivity, and other issues in the prior art of doubly-fed induction motor parameter identification. Based on the dq-axis flux equation and voltage equation of the doubly-fed induction motor, the present invention constructs a state space model with the stator and rotor dq-axis currents as state variables, expands the dimension of the state space model, utilizes the adaptive extended Kalman filter theory, and combines the rank criterion to determine the motor resistance R s 、R r and inductor L s , L r , L m The full observability of all parameters enables full parameter identification of the motor inductance and resistance, and enhances system robustness through adaptive adjustment of noise covariance. This invention effectively eliminates the effects of parameter coupling and improves identification accuracy. The adaptive noise suppression mechanism enhances anti-interference capabilities, meeting the requirements for dynamic online identification of doubly-fed motor parameters.

The purpose of this invention is to provide a marine ammonia-electric hybrid power system based on comprehensive waste heat gradient utilization, including an ammonia fuel engine, a doubly-fed induction motor, a propeller, a gearbox, a clutch, a waste heat recovery system, a power conversion unit, a fuel cell, a thermoelectric power generation module, and a condenser. The technical solution of this invention enables hybrid propulsion of the ammonia fuel engine and the doubly-fed induction motor, while simultaneously achieving gradient utilization of waste heat from the hybrid power system, significantly improving energy efficiency and further enhancing the overall propulsion efficiency of the ship.

The application discloses a kind of concentric cage brushless doubly-fed induction motor reduced-order model and electromagnetic parameter design method, belong to motor design field, method includes: using primary and secondary inductance variation coefficient and primary-secondary mutual inductance variation coefficient respectively simplifies primary winding inductance matrix, secondary concentric cage inductance matrix, primary-secondary mutual inductance matrix;First equation represented by voltage vector, current vector, resistance matrix and simplified inductance matrix is constructed;Using voltage variable ratio matrix and current variable ratio matrix, secondary resistance matrix and secondary concentric cage inductance matrix in first equation are transformed;Primary-secondary mutual inductance matrix in first equation is replaced by newly set primary-secondary mutual inductance matrix, and reduced-order model is obtained, to be used for motor electromagnetic parameter design or optimization.The reduced-order model and electromagnetic parameter design method proposed in the application are more accurate, and the transformation method is simple and practical.

The application provides a control method and device of a doubly-fed induction motor, electronic equipment and a storage medium, and is suitable for the technical field of motor control. The method comprises the following steps: acquiring a plurality of basic voltage vectors of a back-to-back three-level neutral point clamped converter; determining a machine-side pulse width modulation signal based on a machine-side double-vector prediction model and the basic voltage vectors; determining a grid-side first voltage vector and a grid-side second voltage vector from the basic voltage vectors by using a grid-side double-vector prediction model; constructing a symmetrical switching pulse sequence based on the grid-side first voltage vector and the grid-side second voltage vector to generate a grid-side pulse width modulation signal; and outputting the machine-side pulse width modulation signal and the grid-side pulse width modulation signal to a machine-side converter and a grid-side converter respectively. The grid-side pulse width modulation signal of the application adopts a symmetrical switching pulse sequence wave generation mechanism, suppresses even harmonics in a switching period, and reduces the total harmonic distortion of the grid-connected current.

The invention provides a system structure of a double-fed fan, and relates to the technical field of generators. The structure comprises a mechanical system, an electrical system and a power grid, the mechanical system comprises a wind turbine and a gearbox, and the electrical system comprises a doubly-fed induction motor, a back-to-back converter and a transformer; the wind turbine captures wind energy and transmits mechanical energy to the doubly-fed induction motor through the gearbox; the doubly-fed induction motor converts mechanical energy into electric energy, a rotor of the doubly-fed induction motor is an excitation winding in spatial three-phase symmetry, and a stator voltage orientation mode is adopted; the back-to-back converter is used for controlling the operation of the doubly-fed induction motor; the transformer is used for adjusting voltage, connecting the motor with a power grid and providing insulation and protection; the power grid is used for supplying power to the electrical system and receiving or transmitting the generated electric energy to the outside. The system structure provided by the invention has the characteristics of high efficiency, stability and reliability, and a solution for sustainable development and application is provided for the wind power generation technology.

The application aims to provide an ammonia-electric hybrid power system of a ship with a reversible fuel cell, comprising an ammonia fuel engine, a double-fed induction motor, a propeller, a gear box, a diesel generator set, a fuel cell, a hydrogen storage and supply system, a power transformation device, a ship power grid and hydraulic elements, etc. The application can realize hybrid propulsion of the ammonia fuel engine and the double-fed induction motor, coordinated power supply of the diesel generator set and the reversible fuel cell and lithium battery, coupling of the reversible fuel cell and the diesel generator set in the gas path, and further improves the whole-ship propulsion efficiency. The application proposes a gas path coordination scheme of the engine and the fuel cell, can realize complementary advantages of the work of the two, simplifies the gas path design redundancy, and improves the integration of the system.

A system for converting energy includes a doubly-fed induction machine including a rotor having a plurality of rotor windings and a stator having a plurality of stator windings. The system also includes a power conversion unit in electrical communication with the plurality of rotor windings, wherein the power conversion unit is configured to excite the plurality of rotor windings with alternating current. The system also includes a relay unit in electrical communication with the plurality of stator windings, wherein the relay unit is configured to electrically interconnect a plurality of terminals of the plurality of stator windings. The system also includes a controller in electrical communication with the power conversion unit and the relay unit, wherein the controller is programmed to regulate operation of the doubly-fed induction machine using the power conversion unit and the relay unit based on a rotational speed of the rotor.

The application aims to provide a ship ammonia-electric hybrid power system based on the integrated design of a fuel cell and an engine gas circuit, comprising an ammonia fuel engine, a double-fed induction motor, a propeller, a gear box, a diesel generator set, a fuel cell, an ammonia gas storage and supply system, a power transformation device, a ship power grid, and hydraulic elements, etc. The technical scheme of the application can realize the hybrid propulsion of the ammonia fuel engine and the double-fed induction motor, the coordinated power supply of the diesel generator set and the fuel cell, and the lithium battery, and further improves the whole-ship propulsion efficiency. The application proposes a gas circuit coordination scheme of the engine and the fuel cell, which can realize the complementary advantages of the work of the two, simplifies the gas circuit design redundancy, and improves the integration degree of the system.

A charging system and a method of operating the same are provided. The charging system includes an electric machine which may be a wound or un-wound rotor type or a doubly fed induction motor (DFIM). A control system is coupled to the electric machine and a battery system. In the case of a wound rotor, the control system is coupled to stator windings and a rotor winding for controlling excitation of the stator windings and the rotor winding. The charging system is AC and DC compatible. In the case of an AC power source, the control system injects excitation into a rotor winding to induce a desired voltage in the stator, if the power supply voltage of the power supply is greater or smaller than the voltage of the battery system. Other modes of operation allowing for safe charging and discharging of a battery system are also described herein.

A hybrid powertrain for a vehicle includes a doubly-fed induction machine, a first inverter, and a second inverter. A doubly-fed induction machine includes a stator having a plurality of stator windings and a rotor. The rotor includes a plurality of rotor windings and a plurality of slip rings electrically connected to the plurality of rotor windings. The first inverter is arranged to provide a first multi-phase power to the plurality of stator windings and the second inverter is arranged to provide a second multi-phase power to the plurality of rotor windings through the plurality of slip rings. In an example embodiment, a second multi-phase power is provided to a plurality of slip rings through a plurality of brushes. In example embodiments, the number of slip rings is exactly three.

A system is described. The system comprises: a double-fed induction machine (DFIM) coupled to a first axle drive; a first electric machine coupled to a second axle drive; a power supply that supplies a first power to the first electric machine; and a controller. The controller provides the first power to a stator of the DFIM; converts the first power to a second power through a converter based on a message from a sensor module; and supplies the second power to a rotor of the DFIM. In an embodiment, supplying the first power to the first electric machine obtains a first speed and a first torque from the first electric machine on the second axle drive; and supplying the first power and the second power to the stator and the rotor respectively obtains a second speed and a second torque from the DFIM on the first axle drive.

A system for converting energy includes a doubly-fed induction machine including a rotor having a plurality of rotor windings, and a stator having a plurality of stator windings. The system also includes a power conversion unit in electrical communication with the plurality of rotor windings, where the power conversion unit is configured to excite the plurality of rotor windings with an alternating current. The system also includes a relay unit in electrical communication with the plurality of stator windings, where the relay unit is configured to electrically interconnect a plurality of terminals of the plurality of stator windings. The system also includes a controller in electrical communication with the power conversion unit and the relay unit, where the controller is programmed to adjust an operation of the doubly-fed induction machine using the power conversion unit and the relay unit based on the rotational velocity of the rotor.

The invention discloses a self-adaptive demagnetization control strategy for a variable-speed pumped storage unit under low penetration, and the strategy comprises the steps: building a doubly-fed induction motor mathematical model of a variable-speed pumped storage system, and building an exponential decay function of a stator flux linkage based on the doubly-fed induction motor mathematical model, a vector control system of the doubly-fed induction motor is established based on the mathematical model of the doubly-fed induction motor and the exponential decay function, a stator flux linkage reference value and a rotor reference current are dynamically adjusted based on the vector control system, a rotor target voltage is output, and adaptive control is performed on a rotor side converter RSC based on the rotor target voltage. Through fault depth adaptive parameter adjustment, dynamic flux linkage trajectory reconstruction and torque prediction feedback control, rapid clearing and accurate regulation and control of electromagnetic energy during a fault period are realized, rotor current and torque fluctuation are significantly reduced, transition response of a natural flux linkage can be effectively suppressed, electromagnetic oscillation time is shortened, and the fault diagnosis efficiency is improved. And the rotor voltage and current are ensured to operate in an RSC capacity range.