267 results about "Harmonic mitigation" patented technology

The invention provides a big data intelligent decision analysis method and system. The method comprises the following steps: acquiring vibration data and mechanical node stress distribution data in power equipment transportation, and extracting high-frequency harmonic distortion characteristics aligned with a vibration data timestamp; performing cross-domain correlation analysis on stress data fluctuation and harmonic characteristic dynamic change, and identifying a symbiotic mode of mechanical stress abnormality and electrical harmonic distortion by using a machine learning model; based on logistics path planning and equipment constraints, a cooperative control instruction for adjusting the transportation path and the power supply loop parameters is generated through a multi-target cooperative optimization algorithm; and constructing a joint risk assessment matrix, and dynamically adjusting the cooperative relationship between the transportation path and the harmonic suppression parameter according to the quantitative analysis result and the cooperative control instruction to realize the closed-loop decision of the power equipment. According to the technical scheme provided by the invention, the power equipment transportation data processing efficiency is remarkably improved.

The invention discloses a DC voltage divider parameter anomaly detection method based on harmonic characteristics, and the method comprises the steps: deploying an isolation type voltage sensor at a bus of a DC power transmission system, carrying out the voltage sampling through combining with an ADC, carrying out the data buffering and preprocessing, extracting a fundamental wave component and a target harmonic component through the fast Fourier transform, and calculating the harmonic distortion rate. And constructing a low-voltage arm capacitance and harmonic distortion rate model based on a voltage divider secondary circuit equivalent circuit and an energy distribution principle, and calibrating the low-voltage arm capacitance and harmonic distortion rate model. And designing a multi-objective optimization scheduling algorithm based on energy storage capacity and capacitance characteristics, and realizing dynamic power distribution and harmonic suppression of the system. And after abnormal triggering, the system automatically loads a capacitance compensation coefficient, adaptively adjusts algorithm parameters in combination with a measurement loop PI control link, reduces a harmonic amplification effect, and ensures that a measurement error is within an acceptable range. Harmonic monitoring precision and capacitance compensation optimization capability of the direct-current power transmission system are effectively improved, and stable operation of the system is guaranteed.

The invention relates to a rectification harmonic suppression control method for a double reverse star transformer. The method comprises the following steps: establishing a rectifier bridge arm phase characteristic parameter table in a control platform, and recording a theoretical conduction phase, winding attribution and waveform synchronization characteristics of a bridge arm; in the operation process of the rectification control unit, the output current of a transformer and the conduction state of a bridge arm are collected, and a rectification operation state data set is generated; and calculating bridge arm conduction phase deviation, and analyzing a corresponding harmonic component to obtain a mapping relation between a bridge arm state and harmonic distribution. And judging whether the current bridge arm configuration meets the phase coverage requirement of the target rectification pulse number or not according to the mapping result, and if not, selecting a standby bridge arm group with a preset phase difference and generating a switching instruction. And the rectification control unit responds to the instruction to lock the current bridge arm conduction path and release the target bridge arm group so as to realize bridge arm resource dynamic reconstruction and rectification performance optimization. Harmonic waves can be effectively suppressed, and the topology adaptability and the output quality of the rectification system are improved.

The invention provides a wide-voltage self-adaptive closed-loop vector swimming pool pump anti-interference method, and relates to the technical field of motor control and power electronics, and the method comprises the steps: collecting three-phase power supply voltage fluctuation characteristic parameters and motor operation state parameters in real time; performing amplitude compensation and phase synchronization correction on the voltage parameter based on the dynamic voltage compensation factor; a closed-loop vector anti-interference control model is constructed, and model parameters are adjusted in real time through a vector immunity coefficient; dynamically correcting control output by adopting a multivariable feedback regulation mechanism; executing an anti-interference instruction and synchronously updating PWM modulation parameters, and verifying a control effect in combination with hardware-in-the-loop simulation; and parameter self-learning optimization is realized through a genetic algorithm. The dynamic anti-interference capability under power grid voltage fluctuation and harmonic interference is improved, intelligent thermal management is realized through a temperature-voltage-current multi-dimensional coupling model, full-life-cycle self-adaptive optimization of the system is guaranteed, and the problems of compensation lag, insufficient harmonic suppression and poor long-term stability are effectively solved.

The invention discloses a micro-grid electric energy quality global optimization method, which comprises the steps of collecting real-time data, dividing the real-time data into a plurality of segments according to frequency, and calculating harmonic compensation capacity of each frequency band according to the real-time data; according to the harmonic compensation capacity obtained through calculation, priority distribution is carried out on the compensation sequence of the polluted nodes in the micro-grid; the virtual impedance and the injection damping resistance of the inverter are adjusted, and the harmonic current and the resonance phenomenon in the micro-grid are suppressed in different frequency bands; and according to the adjusted virtual impedance and damping resistance, updating a node admittance matrix, monitoring the compensation capacity of the inverter in real time, comparing real-time monitoring data with a threshold value, if the real-time monitoring data exceed the threshold value, correcting the inverter, otherwise, not changing. Through frequency-band-divided control, pertinence and effect of harmonic suppression are improved, frequency-band-divided suppression of micro-grid harmonic and high-frequency resonance is realized, residual capacity of an inverter and harmonic compensation requirements are dynamically matched, and safe and stable operation of a system is ensured.

The invention discloses a decoupling control method and system for a matrix motor with harmonic suppression capability, and belongs to the technical field of motor driving systems, and the method comprises the steps: building a matrix motor current loop mathematical model which considers a DC disturbance term and an AC disturbance term at the same time; based on the matrix motor current loop mathematical model, establishing a self-adaptive quasi-resonance extended state observer which simultaneously considers direct current disturbance observation and alternating current disturbance observation and performs self-adaptive adjustment on control parameters; the direct current and alternating current lumped disturbance of a matrix motor current loop is observed in real time through an adaptive quasi-resonance extended state observer; compensating the observed direct current and alternating current lumped disturbance in a forward controller of the current loop and obtaining a voltage control quantity; and controlling the matrix motor through a voltage vector space transformation and SVPWM modulation method according to the voltage control quantity. The method is improved and optimized based on an existing matrix motor vector control system, and the system does not need to be modified on a large scale.

The invention discloses a GaN totem-pole bridgeless PFC converter harmonic suppression method based on adaptive virtual admittance, and belongs to the technical field of converter control. The invention aims to solve the problem that LC resonance in a GaN totem-pole bridgeless PFC converter in a wide load range causes power grid voltage distortion to be converted into grid-side current harmonics. Comprising the following steps: decoupling a virtual admittance vector in a polar coordinate system, and optimizing under different load working conditions to obtain an optimal virtual admittance set; the system delay influence is compensated to ensure the robustness of the proposed method under different operation conditions; and a load power adaptive virtual admittance mechanism is constructed based on a segmented cubic Hermite interpolation method, so that suppression of network-side specific current harmonics in a wide load range is realized. The self-adaptive suppression method is used for self-adaptive suppression of the grid-side current harmonics of the GaN totem-pole bridgeless PFC converter.

The invention discloses a power supply reliability analysis method and system based on operation and maintenance characteristics of a power distribution network, and particularly relates to the technical field of power supply analysis of the power distribution network. Harmonic data, including harmonic current, harmonic voltage and frequency components, of each node in a power distribution network system are collected in real time; in combination with the topological structure of the power distribution network, the sparse linear equation set is solved through L1 norm optimization, and the main source of harmonic waves is identified; the contribution degree of each nonlinear load to the harmonic distortion of a power distribution network system is calculated, a list of key harmonic sources is screened out through Pareto analysis, a filter configuration optimization model is constructed based on the identified key harmonic sources, and the harmonic distortion level and the filter installation cost are used as constraint functions to optimize the filter configuration. The installation position and the parameter configuration of the filter serve as decision variables, an optimization algorithm is adopted for solving, and the recommended installation position and the parameter configuration of the filter are output; the harmonic suppression effects under different load conditions are evaluated, and the problem that the power supply reliability is reduced due to harmonic distortion is effectively solved.

The invention relates to a coordination method and device for harmonic suppression and reactive power compensation in a power distribution network. The method comprises the steps of obtaining power grid operation parameter information of a power distribution network; according to the power grid operation parameter information, the total current harmonic distortion rate, the power factor and each harmonic current information of the power distribution network are detected; detecting to-be-optimized parameters of the power distribution network according to the total current harmonic distortion rate, the power factor and the current information of each harmonic, the to-be-optimized parameters including at least one of each harmonic and reactive power; and according to the to-be-optimized parameters, suppressing each harmonic in the power distribution network and compensating reactive power in the power distribution network. The method can accurately perform cooperative control on harmonic suppression and reactive power compensation in the power distribution network.

The invention discloses a harmonic suppression method for a network construction type optical storage converter, and belongs to the technical field of new energy. According to the method, the operation of the photovoltaic inverter is adjusted through a constant voltage control strategy, remarkable advantages are shown, the energy loss is effectively reduced by inhibiting the photovoltaic inter-harmonics, and the operation stability of the system is improved. The photovoltaic power fluctuation can be obviously reduced, the energy storage control cost is effectively reduced, and the service life of energy storage equipment is prolonged. Meanwhile, the grid-connected performance is excellent, the distortion rate of grid-connected voltage and current can be reduced, and the electric energy grid-connected quality is improved. In addition, a network construction control method is introduced into the system, the network voltage can be effectively supported, the network frequency can be flexibly adjusted, and the adaptability and supporting capacity of the system to network operation are enhanced. According to the invention, stable operation requirements in different grid-connected environments can be met. The method has important technical innovation in the aspects of improving the operation efficiency, the reliability and the system coordination, and has extremely high application and popularization values.

The invention discloses a high-frequency current harmonic suppression method for a modularized double-winding permanent magnet synchronous motor, and relates to the field of double-winding permanent magnet synchronous motor control. The problems that the cost is increased and energy conversion is not considered due to the fact that multiple inverters are adopted in an existing control strategy are solved. The method comprises the following steps: constructing a double-winding permanent magnet synchronous motor control system, wherein the power supply topology of the double-winding permanent magnet synchronous motor control system is an isolated interleaved parallel topology; obtaining a motor rotor position angle and a rotating speed signal, and calculating a difference value between a rotating speed given signal and a rotating speed feedback signal to obtain d-axis and q-axis current given values of two sets of windings; 6-phase current values are obtained, actual values of d-axis current and q-axis current of the two sets of windings are obtained according to the coordinate transformation matrix, and the difference value of the d-axis current and the q-axis current is solved to serve as input of a current loop PI controller; performing coordinate transformation on the output of the current loop PI controller, and calculating a voltage modulation ratio; and selecting a proper voltage modulation strategy and a carrier phase shift angle to carry out high-frequency current harmonic suppression. The method is applied to the high-frequency current harmonic suppression field.

The invention provides a permanent magnet frequency conversion double-sine modulation swimming pool pump energy-saving control method, and relates to the technical field of motor driving and control, and the method comprises the steps: building a double-sine carrier modulation model of a permanent magnet synchronous motor, and calculating a dynamic harmonic suppression factor and a double-sine modulation depth in real time; feedforward compensation is carried out on the inverter current based on the DHSIF, and a q-axis current reference value is generated by adopting double-closed-loop vector control; dynamically adjusting a carrier frequency range according to the DSMD, generating double sine carriers with a phase difference of pi / 3, and superposing the double sine carriers into a composite modulated wave; the modulation wave amplitude is corrected through a DHSIF, and fifth and seventh harmonics are eliminated in combination with an adaptive filtering algorithm; a carrier wave ratio is dynamically optimized to generate a PWM signal, and a transient compensation mechanism is triggered to correct a voltage instruction when a load suddenly changes; and an energy efficiency optimization database is constructed to call historical optimal parameters, and nonlinear mapping of DHSIF and motor characteristics is established through parameter self-tuning. According to the invention, cooperative control is realized through dynamic harmonic suppression, modulation depth optimization and intelligent thermal protection.

The invention relates to the technical field of power electronics and power transmission, and discloses a distributed multi-device differentiation and anti-interference cooperative harmonic suppression method, which comprises the steps of establishing a power generation data module, a power generation data analysis module, an execution module, an execution feedback module and an optimization upgrading module, the power generation data analysis module calculates data collected by the power generation data module and then establishes a harmonic impedance model in combination with the operation condition and historical data of the equipment, the execution module designs a specific harmonic suppression execution scheme of the harmonic impedance model, and the execution feedback module timely corrects the harmonic impedance model. And the model optimizing and upgrading module performs continuous optimizing and upgrading on the harmonic suppression method of the harmonic impedance model based on the power generation data accumulated for a long time, the feedback information of the execution feedback module and the actual operation experience of the execution module.

The invention discloses a method and device for preventing inverter harmonic waves from affecting operation of an electric energy meter, and the method comprises the following steps: a harmonic attenuation device is installed on an inverter line bus, and the harmonic attenuation device comprises an LC resonance circuit and a control circuit; dynamically matching the winding inductor and the safety capacitor based on the harmonic frequency spectrum characteristic of the inverter; a temperature sensing module is integrated on the body of each power resistor branch; the MCU microcontroller judges whether to trigger power resistor branch switching or not based on the temperature data and a preset temperature control strategy; after a relay switching action is triggered, a dynamic compensation strategy is generated to dynamically adjust inductance, capacitance and resistance topology so as to realize frequency stabilization and impedance matching; and executing closed-loop feedback optimization and health assessment based on the harmonic suppression effect after dynamic compensation and the system operation state. The invention has the following advantages and effects: the dynamic tracking of the LC resonant frequency on the harmonic dominant frequency is realized, and the thermal runaway problem of the harmonic energy absorption unit is synchronously solved.

The invention relates to the field of permanent magnet synchronous motor control, in particular to an RANF adaptive harmonic suppression method based on dustpan line optimization, which comprises the following steps: S1, establishing a d-q axis control model for a permanent magnet synchronous motor, listing voltage, current and electromagnetic torque equations, giving a harmonic current equation, and adopting an ANF adaptive notch extraction algorithm to obtain a harmonic current control model for the permanent magnet synchronous motor; obtaining estimated values of specific-order harmonic amplitude and phase, and generating harmonic compensation quantity from the estimated values by adopting a PI regulator so as to realize a steady-state indifference-free harmonic suppression effect; and S2, in order to solve the problem that the ANF adaptive harmonic suppression algorithm is difficult to follow the d-q axis current rapidly changing along with the direct current amount, an RANF adaptive harmonic suppression algorithm adopting an R regulator is proposed, the ANF following performance is greatly accelerated, and the practicability of the ANF is improved. When the motor load or the rotating speed changes, quick response can be achieved, system instability is avoided, the dynamic stability of the system is remarkably improved, and the application scene of ANF adaptive harmonic suppression in the permanent magnet synchronous motor is widened.

The invention discloses a vector reconstruction harmonic suppression method for a three-level inverter power supply permanent magnet synchronous motor, and relates to the technical field of motor harmonic and noise suppression. Calculating action time of three basic vectors, selecting the three basic vectors, adjusting an original vector synthesis sequence in a single carrier period into a vector reconstruction synthesis sequence, calculating three time nodes of a fifth-segment sequence and a sixth-segment sequence according to the original vector synthesis sequence, and calculating the time nodes of the fifth-segment sequence and the sixth-segment sequence; the action duration of the two basic vectors after adjustment is calculated according to the vector reconstruction synthesis sequence, the numerical value of a switching time node of a three-level inverter switching tube is updated according to the action duration, and the assigned value of a time register is calculated and updated in a circulating mode in the operation process of the permanent magnet synchronous motor system. And generating a PWM (Pulse Width Modulation) driving signal to control a three-level inverter switching tube to drive a motor. Improvement is carried out based on a traditional SVPWM technology, the high-frequency harmonic performance of the three-level inverter and the motor driving system can be remarkably improved, system cost and operation difficulty do not need to be increased, and the method is simple and easy to implement.

The invention provides a network construction type bidirectional low-harmonic energy storage converter based on virtual synchronous control and an intelligent load identification method thereof, and belongs to the field of power electronics. The converter comprises a power module and a control module, wherein the power module is used for bidirectional conversion and output of electric energy; the control module comprises a virtual synchronous control module and a harmonic suppression control module, and the virtual synchronous control module adopts a virtual synchronous generator technology to realize active / reactive power bidirectional adjustment during electric energy bidirectional conversion of the power module and network construction level voltage and frequency support during electric energy output; and the harmonic suppression module is provided with a parallel QPR controller group (comprising a first QPR controller, a second QPR controller and a third QPR controller) which are used for processing third-time, fifth-time and seventh-time characteristic harmonics respectively and suppressing the characteristic harmonics of the electric energy output side of the power module. According to the invention, the dual modules are arranged in the control module, so that the cooperation of a network construction function and low harmonic output is realized, and the electric energy quality and the system operation stability are effectively improved.

The invention relates to the technical field of power quality control, and discloses an inverter harmonic suppression cooperative control method, device and equipment and a storage medium, and the method comprises the steps: employing sliding window recursive discrete Fourier transform to decompose output voltage harmonic waves in real time; generating a reverse compensation voltage for the detected harmonic component; dynamically adjusting the sampling frequency according to the load current change rate; and superposing a high-frequency jitter signal in the modulated wave. Therefore, the problem of balance among harmonic suppression efficiency, dynamic response speed and system loss of a traditional inverter is solved. The dynamic switching frequency is adaptive, and various switching frequencies can be switched to replace traditional fixed frequency modulation based on the load current change rate; harmonic compensation is adopted, PR, namely SMC double closed-loop control is matched, low-harmonic high-quality waveform output is achieved, and meanwhile the anti-interference performance of the system is improved.

To reduce cost of an entire harmonic filter facility and downsize the harmonic filter facility.SOLUTION: A harmonic filter facility suppressing harmonic components included in AC voltage of a bus that is a harmonic suppression target has an LC series circuit composed of a first reactor element connected to the bus and a capacitor element connected to a low pressure side of the first reactor element, and a second reactor element connected to the capacitor element in parallel in the low pressure side of the first reactor element. Anti-resonance orders of the capacitor element and the second reactor element are set to a higher order than a fundamental frequency.SELECTED DRAWING: Figure 1

The invention discloses a harmonic suppression method and system based on feedforward control and virtual impedance, and belongs to the field of electric energy quality control, and the method comprises the steps: constructing a harmonic extraction model based on the cascading of double third-order generalized integrators, and obtaining a voltage harmonic component based on the harmonic extraction model and real-time power grid data; based on a preset power outer loop control strategy, a preset voltage and current double closed loop control strategy, a preset harmonic voltage feed-forward control strategy and the voltage harmonic component, constructing a network construction type charging pile control model, and obtaining an initial output current; obtaining each virtual impedance based on the initial output current, the harmonic extraction model and the voltage harmonic component; and obtaining a harmonic suppression model based on each virtual impedance and the network construction type charging pile control model, so as to obtain a harmonic suppression output current based on the harmonic suppression model and the real-time power grid data. According to the harmonic suppression method and system based on feedforward control and virtual impedance provided by the invention, grid-connected output current harmonics controlled by a network-forming type charging pile are effectively suppressed.

The invention discloses a harmonic suppression and dynamic reactive compensation control method for an energy router, which is suitable for a micro-grid and a distributed energy access system. According to the method, three-phase current and voltage signals of an alternating current port of the energy router are collected, five-time and seven-time main harmonic components are extracted through fast Fourier transform, harmonic compensation current instructions equal in amplitude and opposite in phase are generated and injected into an inverter to be output, and active counteracting of main harmonics is achieved. Meanwhile, the bus voltage deviation and the change rate thereof are detected, a reactive current instruction is adjusted on line by adopting a fuzzy self-adaptive PI controller, rapid and smooth dynamic reactive compensation is realized, and the bus voltage is stabilized. Decoupling control of active / reactive and harmonic components is realized in combination with Park conversion, and virtual impedance is introduced to enhance system damping and harmonic suppression capabilities. Compared with the prior art, harmonic suppression and voltage support can be simultaneously realized under a single control framework, the response speed is high, the stability is high, and the method is suitable for high-performance grid-connected operation of the multi-port energy router.

The invention discloses a six-phase motor driver harmonic current suppression method based on multi-subspace control, and belongs to the technical field of motor control. In order to solve the problem that low-order harmonic current of a six-phase motor in a z1-z2 subspace is difficult to effectively suppress, the invention provides a scheme that a mathematical model of the six-phase permanent magnet synchronous motor is established, multi-subspace decomposition is carried out, and stator current is divided into a d-q subspace and the z1-z2 subspace; a double-closed-loop control architecture with a speed loop as an outer loop and a current loop as an inner loop is constructed, a d-q subspace adopts a PID regulator to realize fundamental current control, and z1-z2 subspaces realize suppression of fifth and seventh harmonic currents through a parallel structure of PI and a quasi-proportional resonance controller; and a PWM signal is synthesized through inverse transformation and dual three-phase space vector pulse width modulation, and an inverter is driven to realize stable output of fundamental wave energy and harmonic suppression. The method effectively reduces the harmonic distortion rate, improves the operation efficiency and stability, and is suitable for occasions of new energy vehicles, ship propulsion, rail transit and the like.

The present invention provides a method for flexible harmonic control of a ship photovoltaic inverter. The method adopts a control structure in which a grid-connected current command current link and a compensation command current link are connected in parallel, so as to realize flexible switching between a harmonic compensation mode and a harmonic suppression mode. The voltage and current dual closed-loop control is adopted. The voltage outer loop adopts PI control to stabilize the DC side capacitor voltage and output the grid-connected active command current. The current inner loop adopts a parallel PI+repetitive controller to realize zero-static error tracking of the command current. In the harmonic compensation mode, the inverter output current includes the grid-connected active current and the compensation current to compensate for the harmonic current generated by the nonlinear load of the power grid. In the harmonic suppression mode, the inverter's ability to suppress power frequency harmonics is effectively improved, high-quality grid-connected current is output, and the total harmonic distortion rate of the grid-connected current is reduced. The present invention realizes the use of the redundant capacity of the inverter to compensate for grid harmonics when the inverter is lightly loaded; when the inverter is heavily loaded or fully loaded, the inverter operation stability is improved.

The invention relates to the technical field of data center energy storage, and discloses a data center flywheel energy storage system and method based on an LCL filter, and the method comprises the steps: collecting a power grid side current signal, decomposing a harmonic component, and dynamically adjusting the parameters of the LCL filter to suppress harmonic waves; determining and executing a charging and discharging control strategy according to the direct-current bus voltage and the flywheel rotating speed; flywheel vibration and acceleration are monitored in real time, operation stability is evaluated, and a control strategy is corrected; and the harmonic suppression effect is optimized by combining rotating speed feedback and voltage data compensation filter parameters. The system comprises a harmonic suppression module, a charge and discharge control module, a stability evaluation module and a filtering parameter optimization module. Through multi-parameter dynamic adjustment and multi-module cooperative control, composite suppression of power grid harmonics and accurate adjustment of the flywheel energy storage state are achieved, the system operation stability and the filtering effect are improved, and the method is suitable for a data center energy storage scene.

The invention relates to the field of three-level inversion twin-trawling systems, and particularly discloses a harmonic current suppression method, system and product of a three-phase three-level inversion twin-trawling system, and the method specifically comprises the following steps: S1, a bus voltage balance control step; s101, acquiring a bus voltage error value; s102, acquiring a bus voltage error correction value; s2, a neutral current harmonic suppression step; s201, acquiring a common-mode current flowing through a node connected with the power side and the load side; s202, acquiring a higher harmonic component in the common-mode current; s203, obtaining a higher harmonic component suppression correction value; and S3, superposing the corrected value and a three-phase voltage output modulation wave to obtain a three-phase inverter circuit modulation signal of a power side in the three-phase three-level inverter twin trawling system. The harmonic suppression algorithm of the output current can be provided based on the single-power three-phase dragging system, the cost can be reduced, and the current distortion can be reduced, so that the real current output condition can be simulated.

The invention discloses a high-linearity low-noise amplifier based on harmonic suppression, relates to the field of communication and the technical field of electronic devices, and is used for solving the problem that the noise coefficient of an existing Darlington structure is large. Comprising a noise matching and input matching network, a linearity enhancement structure, a negative feedback structure and a pre-distortion structure. Wherein the linearity enhancement structure at least comprises a first amplification transistor and a second amplification transistor which are arranged in parallel, and is used for improving the linearity of the circuit through harmonic cancellation; the negative feedback structure is connected with the noise matching and input matching network and the pre-distortion structure and is used for expanding circuit bandwidth and optimizing output matching; the pre-distortion structure is used for stabilizing the bias voltage of the third amplification transistor. According to the invention, the linearity of the whole circuit is effectively improved, and the source microstrip lines of the two circuits are utilized to improve the minimum noise matching and improve the noise performance. Noise is reduced, linearity is improved, low-frequency gain is suppressed, and bandwidth of the whole circuit is improved.

The invention discloses a dual three-phase permanent magnet synchronous motor harmonic suppression method based on virtual back electromotive force identification, and the method comprises the following steps: S1, building a driving system model of a DTP-PMSM; s2, constructing a harmonic model of the DTP-PMSM, analytically decomposing the nonlinear characteristic and the non-sinusoidal counter electromotive force of the inverter into dq and dqz subspaces, introducing the concept of virtual harmonic counter electromotive force, and unifying the nonlinearity of the inverter, the space harmonic counter electromotive force and cross coupling terms related to harmonic current into a single expression form; and S3, developing an identification principle based on current mapping, including amplitude and phase estimation, gain design and delay compensation, so as to estimate the amplitude and phase deviation of the virtual harmonic back electromotive force on line to realize harmonic suppression and avoid a complex algorithm and a large amount of parameter adjustment. According to the method, the operation effect is good in a wide rotating speed range, and meanwhile complex algorithms and a large amount of parameter adjustment are avoided.

A method for suppressing current harmonics of a permanent magnet synchronous motor relates to the field of permanent magnet synchronous motor control, and comprises the following steps: Step 1: designing a model reference adaptive system, including three parts: a reference model, an adjustable model and an adaptive module, to realize online identification of time-varying parameters of resistance and inductance. Step 2: designing a harmonic injection system, extracting 6x±1 times current harmonics (x is a natural number), and calculating harmonic voltage compensation. Step 3: injecting the harmonic voltage compensation calculated in step 2 into a permanent magnet synchronous motor vector control model to suppress 6x±1 times current harmonics. The present invention can identify key time-varying parameters of the harmonic injection link online during the operation of the permanent magnet synchronous motor, improve the harmonic suppression effect under time-varying motor parameters, reduce the vibration and noise of the permanent magnet synchronous motor, and realize it through software optimization, without adding additional hardware and cost, and is easy to realize.

The invention discloses an electric energy quality optimization method and system based on carrier modulation, and relates to the field of electric energy quality optimization, and the method comprises the steps: obtaining bridge arm information of a distributed energy storage type electric energy quality controller, and determining a carrier amplitude adjustment strategy; determining a target zero-sequence component needing to be injected through carrier characteristics based on the carrier amplitude adjustment strategy; according to the target zero-sequence component, performing superposition on the original modulation wave to generate a target modulation wave; adjusting the power of the power grid based on the target modulating wave, and carrying out dynamic compensation on the capacitance voltage deviation; the harmonic suppression capability is improved, and the power distribution dynamic response efficiency is enhanced, so that the optimization of the electric energy quality is realized, and the problem that the real-time performance and the reliability of the electric energy quality regulation are reduced due to the limitation of harmonic compensation and the lack of real-time dynamic response in the conventional pulse width modulation method is solved.

The invention discloses a harmonic suppression method based on virtual impedance cooperative control, relates to the technical field of power grid harmonic control, and is used for solving the technical problems of high harmonic time variation, high treatment energy consumption and parameter solidification in a high-permeability photovoltaic scene. The method comprises the following steps: acquiring an original electric signal and an impedance parameter of a power grid side and a filtering parameter of an inverter side; performing real-time phase correction according to the original electric signal to obtain a multi-band harmonic frequency; virtual impedance is constructed based on the multi-band harmonic frequency, and an impedance characteristic matrix is generated based on the impedance parameters and the filtering parameters; performing parameter optimization based on deep reinforcement learning on the virtual impedance by adopting the impedance characteristic matrix to obtain an optimal virtual impedance parameter; and changing the equivalent output impedance of the inverter through the virtual impedance under the optimal virtual impedance parameter so as to realize harmonic suppression.