4results about How to "Broaden the stable operating range" patented technology

The application relates to a kind of twelve-phase permanent magnet motor control methods based on rotating shaft position observation, belong to motor control technical field. By equivalent twelve-phase permanent magnet synchronous motor to four three-phase control units;Design state observer based on rotating shaft for each unit to observe back electromotive force;Through phase-locked loop, the rotor position and speed signal of each unit is extracted from back electromotive force;According to master-slave control method, select one from four control units as master controller, use the rotor position and speed signal corresponding to the master controller as the final observation result of the system;At the same time, it is used as feedback signal, input to the double closed loop vector control system of twelve-phase permanent magnet synchronous motor, realize twelve-phase high-speed permanent magnet synchronous motor sensorless control. The observer based on rotating coordinate system of the application is better designed, and is more stable when low carrier ratio control.

The application discloses an oscillation suppression method and system of a grid-following and grid-forming inverter hybrid system, and comprises the following steps: establishing a grid-following inverter decomposition model, and separating out a negative damping component causing instability of the grid-following inverter; designing a compensation term based on the negative damping component, injecting the compensation term into a grid-forming inverter, and reshaping output impedance of the grid-forming inverter to offset the influence of the negative damping component of the grid-following inverter on system stability. The negative damping component is injected into the grid-forming inverter after being taken in reverse, and a compensation term of the output impedance of the grid-forming inverter can be calculated, so that the influence of the negative damping component of the grid-following inverter on system stability is offset.

This invention discloses a co-firing biomass gas burner and method, belonging to the technical field of combustion equipment. The burner includes a central duct, an inner secondary duct, and an outer secondary duct, coaxially arranged from the inside out. A pulverized coal concentrator is installed inside the central duct, and its outlet end has a slitted blunt body structure with a central through-hole and an axial slit, used to form a graded pulverized coal gas flow. The biomass gas pipeline is equipped with a mechanical tar reduction structure based on temperature detection and flow rate regulation. Through the cooperation of the pulverized coal concentrator, the slitted blunt body, the secondary air swirl blades, and the guide plate, a series of primary and secondary recirculation zones are formed within the burner, achieving zoned mixing and graded combustion of pulverized coal and biomass gas. This invention solves the technical problems of incomplete co-firing, tar blockage, and low-NOx combustion in existing technologies, improving combustion efficiency, stable combustion performance, and reducing pollutant emissions.

The invention discloses a grid-connected inverter stability control method based on an improved phase-locked loop, and belongs to the technical field of new energy grid-connected control, and the method comprises the steps: firstly building a grid-connected inverter impedance model, and revealing a mechanism that the phase-locked loop introduces negative damping and reduces stability margin under a weak power grid; based on an impedance model, a composite control strategy fusing dynamic feed-forward compensation and an improved Kalman observer is designed, the former actively counteracts the negative impedance effect of a phase-locked loop, and the latter improves dynamic response through state reconstruction and advanced prediction. Finally, an improved cascade delay signal elimination phase-locked loop with a selective conduction harmonic filtering function is provided, and the improved cascade delay signal elimination phase-locked loop is deeply integrated with the control strategy and a multi-harmonic feedback link, so that high-precision phase locking and active harmonic suppression are realized. According to the method, the operation stability, the dynamic performance and the electric energy quality of the grid-connected system under the conditions of high background harmonic waves and weak power grids are remarkably improved.