7results about How to "Good harmonic suppression effect" patented technology

The invention discloses a high-reliability complex coefficient repetitive control grid-connected inverter control system and method suitable for a power supply protection scene, and the method comprises the steps: building an LCL type grid-connected inverter mathematical model under an alpha-beta static coordinate system for a three-phase grid-connected inverter, and saving Park transformation and decoupling calculation under a dq coordinate system; a complex coefficient filter H (s) and a complex coefficient repetitive controller are designed to form a double-input double-output control structure, and a complex coefficient imaginary part omega m is set to be equal to a fundamental frequency omega 0, so that the gain of the controller at the fundamental frequency is infinite, and complete tracking of periodic signals is realized; and the dynamic response capability of the system is improved by combining an output feedback control law. According to the method, the grid-side voltage imbalance and harmonic pollution can be effectively suppressed, the grid-connected current THD can be remarkably reduced, and the method has good dynamic control performance and robustness, is suitable for a grid-connected power generation system of new energy such as solar energy and wind energy, and plays an important supporting role in improving the power supply reliability and supply guarantee capability of a power system under the new energy access background.

The present application relates to a kind of LLCCL filter grid-connected energy storage converter wide-frequency collaborative harmonic suppression method and system.Belongs to new energy grid-connected power electronic control and power quality management technical field.The method is set between converter and public coupling point LLCCL filter, and PCC voltage, net side current and filter branch current are collected;According to the power given value, the net side current reference value of bidirectional power operation is generated;Through the active damping of branch current feedback, LLCCL filter resonance peak is inhibited, through the proportional resonant controller containing fundamental wave and low-order harmonic resonance term and PCC voltage feedforward, low-order current distortion caused by background voltage harmonic is inhibited, and high-frequency attenuation is carried out on switching frequency related side frequency component by LLCCL filter.The present application can collaboratively inhibit low-order background harmonic, filter resonance and switching frequency related high-frequency harmonic in the same control framework, improve the grid-connected current quality and operating stability of energy storage grid-connected converter.

The invention discloses an intelligent harmonic suppression method and system for a stator core for a motor. The method comprises the following steps: acquiring the resistivity of an iron core material, the resistivity of an insulating layer between laminations, the space harmonic order of a stator winding, the working frequency of the motor, the actual working temperature of the iron core, the maximum magnetic flux density of the iron core and the amplitude of a fundamental current; dynamically correcting the eddy current coupling coefficient by combining the actual working temperature of the iron core and the maximum magnetic flux density; calculating a v-order harmonic current amplitude based on the corrected eddy current coupling coefficient; calculating a v-harmonic compensation voltage amplitude; and outputting the matched compensation voltage to the stator winding. The system comprises a parameter acquisition module, an eddy current coupling coefficient correction calculation module and the like. The method solves the problem of harmonic measurement deviation caused by neglecting the dynamic working condition in the existing scheme, improves the adaptability of harmonic suppression, and is suitable for a motor stator core harmonic control scene.

The utility model discloses a kind of harmonic absorption circuits of short wave filter, circuit includes RF power amplifier, low-pass filter module and high-pass filter module, the high-pass filter module is connected in parallel at the input end of the low-pass filter module, and the input end of low-pass filter module and high-pass filter module is respectively connected in parallel by the RF power amplifier output signal. The scheme adopts the mode of connecting high-pass filter in parallel at the input end of low-pass filter, and the passband of high-pass filter is set as the out-of-band harmonic suppression frequency band of wave band, 50Ω power resistance is connected at the output end of high-pass filter to absorb harmonic power, improve the harmonic suppression performance of short wave communication equipment and improve the working life of power amplifier tube.

The embodiment of the invention discloses a new energy grid-connected harmonic suppression regulation and control method and device, electronic equipment and a medium. A specific embodiment of the method comprises the following steps: performing variable window Fourier transform on a power instantaneous value sequence set, and then performing impedance compensation to obtain a compensated power harmonic spectrum diagram set; performing critical point identification on the new energy grid-connected power region to obtain a harmonic resonance critical point set; performing early warning grade division on the harmonic resonance critical point set to obtain an early warning grade critical point set; performing harmonic time sequence prediction on the compensated power harmonic spectrogram and the inverter power information to obtain a harmonic prediction amplitude oscillogram; and performing harmonic suppression control on the early warning grade critical point to obtain grid-connected harmonic regulation and control information, and performing equipment regulation and control processing on the power equipment. According to the embodiment, the early warning accuracy of the harmonic resonance risk and the efficiency of suppressing the harmonic resonance can be improved, the equipment delay is reduced, the safety of the new energy grid-connected equipment is improved, and the power loss is reduced.

This invention discloses a method and system for motor parameter identification based on a multiple synchronous rotating coordinate transformation filter. The method includes: using the motor's voltage and current along the αβ axis, along with position estimation information from a quadrature phase-locked loop (PLL), as inputs to a sliding mode observer to obtain back electromotive force (EMF) observations. The sliding mode algorithm employs a switching function to suppress high-frequency chattering in the back EMF. Furthermore, the harmonic disturbances in the back EMF are filtered out using a multiple synchronous rotating coordinate transformation filter. The fundamental component of the back EMF is then passed through the PLL to obtain the rotor's estimated speed and position information. The proposed multiple synchronous rotating coordinate transformation filter can be applied to sensorless motor control systems, eliminating the fifth and seventh harmonics in the estimated back EMF and exhibiting excellent harmonic suppression. This enables real-time and accurate acquisition of motor position information, improving the control performance of the motor drive system.

The invention provides a grid-connected inverter harmonic suppression method based on double-vector model predictive control, and the method comprises the steps: building an inverter prediction model under an alpha-beta static coordinate system, separating an output current into a fundamental component and a harmonic component, and carrying out the prediction control of the fundamental component and the harmonic component; a dual-target optimization function containing a fundamental wave weight coefficient eta and a harmonic wave weight coefficient gamma is constructed, minimization of an error area between PCC harmonic current and a zero axis is taken as a harmonic suppression target, and a dual-vector model is combined to predict and control a dynamic optimal voltage vector and action time thereof, so that coordinated optimization of fundamental wave power transmission and harmonic suppression is realized. The method can effectively reduce the total harmonic distortion rate at the PCC, improves the electric energy quality of a multi-inverter parallel system, and is suitable for an alternating current bus system containing multiple harmonic sources.