101 results about "Active power filter" patented technology

The invention provides an APF and SVG cooperative control-based electric energy quality comprehensive treatment system, and belongs to the technical field of intelligent power grid industry and electric energy quality comprehensive treatment, and the system comprises the steps of obtaining a power grid current signal and a voltage signal, and detecting a harmonic component and a voltage deviation through a harmonic detection module; a collaborative decision controller is adopted to determine a compensation strategy according to the harmonic component and the voltage deviation, and compensation tasks of an active power filter channel and a static var generator channel are distributed; harmonic compensation current is generated through an active power filter channel, and high-frequency harmonics are suppressed; reactive compensation current is generated through a static var generator channel, and voltage fluctuation is stabilized; and the compensation current is filtered through the filtering module and is output to a power grid. The electric energy quality comprehensive treatment system can effectively inhibit power grid harmonic waves, stabilize voltage fluctuation and improve electric energy quality, and is suitable for a complex power grid environment.

The invention belongs to the technical field of power electronics, and provides a method and a system for improving harmonic transient stability of a grid-forming type active power filter, droop control is performed on a deviation value of an active power reference instruction and an actually measured active power value, integration is performed to obtain a power angle, and the power angle and a grid-side harmonic phase are added to generate a harmonic voltage phase instruction; pI control is carried out on a deviation value between the reactive power reference instruction and an actually measured reactive power value to obtain a voltage deviation value, and the voltage deviation value and a network side specified subharmonic voltage amplitude are summed to generate a harmonic voltage amplitude instruction; taking a harmonic voltage amplitude instruction as a d-axis reference, taking 0 as a q-axis reference, respectively subtracting the d-axis reference and the q-axis reference from the harmonic voltage on the d-axis and the q-axis to obtain deviation values, and obtaining a dq component of the harmonic voltage reference through PI control. The operation safety of the power grid can be improved.

The invention relates to a harmonic suppression and dynamic voltage compensation method based on a composite control series filter, and belongs to the field of power electronic technology and electric energy quality control. Harmonic current passing through a primary winding of a transformer and a sudden rising or falling signal of power supply voltage are extracted, and after the two signals are controlled and combined into a reference signal, a voltage source inverter (VSI) connected with a secondary side of the transformer in parallel shows a controllable voltage characteristic. The control parameters of the harmonic current can enable the transformer to present relatively large controllable impedance to harmonic waves, so that harmonic wave isolation is realized. In addition, the VSI compensates for the system voltage deviation by detecting the voltage drop. And finally, establishing a simulation model to verify that the series active power filter based on the control strategy can isolate harmonic waves and effectively compensate voltage deviation. Harmonic suppression and dynamic voltage compensation functions can be realized at the same time, and the power quality of a middle-high voltage system is improved.

The invention provides a phase delay test and compensation method for an active power filter, and the method comprises the steps: generating a sine wave control signal with the frequency range of 1 kHz to 20 kHz through an FPGA, and driving a half-bridge inverter of the active power filter to output an analog signal; measuring delay time of three delay links in the active power filter by modules, wherein the delay time comprises delay 1 of an error detection link, delay 2 of an inversion link and delay 3 of a digital processing link; and taking the sum of the delay 1 of the error detection link, the delay 2 of the inversion link and the delay 3 of the digital processing link as the total delay of the system, introducing a phase compensation parameter in an LMS algorithm, and adjusting the phase of the offset current to enable the phase difference between the offset current and the harmonic current of the power grid to be 180 + / -5 degrees. According to the technical scheme, the delay parameter in the active power filter can be measured, phase alignment of the output signal of the active power filter and the harmonic current in the power grid is achieved in a compensation mode, and suppression of the harmonic current of the power grid is achieved.

The invention discloses an active power filter residual life evaluation method, system and device, a medium and a product, and the method comprises the steps: constructing a failure degradation model of a DC side capacitor of an active power filter and a failure degradation model of an IGBT power module through a Wiener process; determining an edge cumulative distribution function of the direct-current side capacitor and an edge cumulative distribution function of the IGBT power module, coupling the edge cumulative distribution function of the direct-current side capacitor and the edge cumulative distribution function of the IGBT power module by using a Copula function, and based on a joint degradation probability distribution model, performing Monte Carlo simulation to obtain a degradation probability distribution model. According to the method, the degradation tracks of the direct current side capacitor and the IGBT power module from the starting moment to the future moment are simulated, and when any one degradation track passes through the failure threshold value, the latest moment is determined as the degradation moment, so that the residual life estimation value of the active power filter is determined, and the precision of residual life estimation is improved.

The invention provides a harmonic detection and treatment method and equipment used in an electric power system, and belongs to the technical field of electric power systems, and the method specifically comprises the steps: determining the harmonic influence type of a switch cabinet according to the temperature monitoring data of the switch cabinet in different harmonic current intervals, according to the method, the monitoring load interval is determined according to the switch cabinet data of different harmonic influence types, and when the switch cabinet is in the monitoring load interval of the active filter, whether harmonic detection processing is needed is determined according to the temperature detection data of the switch cabinets of different harmonic influence types, so that the working stability and reliability of the active filter are improved.

The application discloses a harmonic compensation and stability improvement method, system, medium and equipment, filters components of a grid voltage in a two-phase static coordinate system to obtain corresponding fundamental components; subtracts the fundamental components of the grid voltage from the components of the grid voltage in the two-phase static coordinate system to obtain total harmonic components of the grid voltage; filters the total harmonic components of the grid voltage by using multiple band-pass filters to obtain multiple harmonic components corresponding to frequencies; subtracts reference current instructions of an active power filter from the multiple harmonic components, and inputs the result as a new current reference instruction into a current controller; and based on a virtual harmonic admittance method, outputs harmonic compensation currents through current inner loop control in the two-phase static coordinate system to realize harmonic compensation on a nonlinear load with frequency coupling characteristics and suppression of harmonic compensation oscillation. The application can adapt to various complex grid environments and has relatively practical engineering application value.

The application discloses a kind of electric energy metering box systems based on harmonic identification compensation, including signal pre-processing module, offline training module, online inference module and harmonic reconstruction and compensation module.Signal pre-processing module is framed according to time window to the current signal collected, generates frequency spectrum label count vector.Offline training module executes variational expectation maximization training of implicit Dirichlet distribution model to historical frequency spectrum label corpus, learns the frequency spectrum signature distribution and feature template of multiple harmonic source mode.Online inference module solidifies the parameter obtained by training, executes lightweight variational inference iteration, estimates the harmonic source mixing proportion vector of current frame.Harmonic reconstruction and compensation module carries out weighted vector synthesis to mixing proportion vector and feature template, generates compensation current reference signal output to active power filter.The application can realize sub-millisecond level real-time harmonic source mode identification and compensation in resource-limited embedded environment.

The application discloses an active power filter control method for preventing resonance, and relates to the technical field of power quality control.The method injects a harmonic current with a frequency of a pre-judged harmonic frequency into a power supply circuit, compares the change in the grid-side current and the load-side current before and after the injection, obtains a sensitive frequency point, separates the harmonic component corresponding to the sensitive frequency point from the harmonic components corresponding to other frequencies, and respectively generates compensation currents, wherein the harmonic component corresponding to the sensitive frequency point is adjusted through a feedback coefficient, different compensation currents are superimposed to obtain a comprehensive compensation current, the comprehensive compensation current is used to offset the load harmonic current, and the grid-side current is ensured to be undistorted.The technical scheme in the application can realize harmonic impedance adjustment, effectively prevent harmonic amplification, avoid passive element burning or power supply failure, and enhance the safety and reliability of power supply.

A control system including a power grid configured to supply a grid voltage, a filter capacitor and a filter inductor each connected in parallel to the power grid, a filter current meter connected in series to the filter inductor, an active power filter connected to the filter current meter, a nonlinear load connected in series to the power grid, and a modulated model predictive controller (MMPC) configured to generate a control signal for operating the active power filter.

The utility model relates to the technical field of electrical connection, in particular to an electricity-saving and energy-saving terminal electrical comprehensive treatment protection module, which comprises a central control module used for data processing and circuit integral control, and an enhanced active power filter module used for adjusting three-phase imbalance, the bus capacitor module is used for balancing current of each phase through charging and discharging, and the enhanced active power filter module comprises a sampling module used for detecting voltage and current of a system side in real time; and the compensating current generating circuit is used for controlling the on-off of the three-phase circuit to absorb energy from the power grid and mutually convert the energy among the three-phase circuit so as to enable the three-phase current to reach a balanced state. According to the utility model, real-time detection of system side current can be carried out, on-off of the three-phase circuit is controlled, energy is absorbed from a power grid and is mutually converted among the three-phase circuit, so that three-phase current reaches a balance state, and the like, thereby eliminating total harmonic distortion of the power grid with low harmonic, compensating reactive power, improving power factor of the power grid, and reducing power consumption. And an energy-saving node effect is achieved.

The invention relates to the technical field of power system automation and electric energy quality control, in particular to an electric energy quality optimization control method and system based on distributed collaborative decision. The method comprises the following steps: deploying synchronous phasor measurement units and corresponding edge intelligent decision nodes at a plurality of nodes of a power grid, and constructing a distributed network; each node calculates an electric energy quality characteristic index based on local data; dynamic role negotiation is carried out through local communication, and a leading controller is determined; the dominant controller fuses strategies and confidence information of local and adjacent nodes to generate a cooperative control strategy; and finally, equipment such as a static var generator and an active power filter is controlled to perform coordinated execution. Through a decentralized collaborative decision-making mechanism, the defects that centralized control is slow in response and low in reliability are overcome, rapid self-adaptive treatment on voltage sag, harmonic waves and other problems is achieved, and the response speed, the treatment success rate and the system robustness are remarkably improved.

The application discloses a kind of multi-module active power filter control methods, comprising: detecting load current effective value, according to the size relationship and duration of load current and preset load current threshold, start or stop the operation of active power filter module;According to the output current of the preset capacity allocation strategy of active power filter module is distributed, and the running load rate of the active power filter module being calculated is operated;According to the size relationship and duration of running load rate and preset expected load rate upper limit and preset expected load rate lower limit, start or stop the operation of active power filter module.By the technical scheme of the application, the function that multiple module output currents are automatically distributed according to the size of load is realized, so as to conveniently realize the control of the whole system output and start-stop current, improve the compensation accuracy effect, prolong the service life of the whole system, improve the stability, reduce the failure rate.

The invention provides a harmonic suppression method, device and equipment for a Hull moving average filter and a medium. The harmonic suppression method comprises the steps of collecting load end current; based on an improved harmonic current detection method, a harmonic current instruction signal is detected and extracted according to a load end current; controlling the harmonic current command signal to pass through an active power filter to generate a compensation current; and the compensation current is injected into the power grid. The technical problems that in a traditional harmonic and reactive current detection method, unavoidable losses are brought to the dynamic response speed and accuracy of current detection, and the harmonic compensation performance of a system is finally affected are solved.

A wind power grid impact damping suppression method based on branch and bound and knapsack optimization control can realize efficient and rapid suppression of wind power fluctuation. The device is characterized by combining the advantages of thyristor switched filter (TSF) and active power filter (APF), and developing active damping generator technology based on knapsack optimization control for wind power grid impact suppression. The developed ADG technology has the following advantages: ① It has the characteristics of TSF harmonic impact suppression, voltage mutation and high cost performance; ② It has the characteristics of APF output damping continuous adjustable and high precision; ③ Based on branch and bound, the wind power impact is classified as the reference of the maximum damping of ADG output, which effectively improves the rapidity and stability of ADG response; ④ The knapsack problem (UKP) is used to realize the optimal switching control of ADG, which meets the minimum cost and efficient wind power disturbance impact suppression.

The invention relates to a wheel polygon wear suppression method, an inter-harmonic excitation suppression circuit, a method and a medium, and relates to the technical field of railway traction transmission. On the basis of inter-harmonic excitation suppression and polygon wear feedback suppression, the malignant feedback effect caused by electromechanical coupling is weakened, and therefore suppression of polygon wear development of the wheel is achieved; the inter-harmonic excitation suppression comprises the following steps of: arranging an active power filter in a direct current link, and compensating direct current link power fluctuation caused by harmonic waves introduced by a rectifier; the polygon abrasion feedback suppression comprises the steps that compensation current is calculated based on the rotating speed fluctuation quantity under polygon abrasion excitation, and the T-axis current of the motor is compensated. According to the scheme, corresponding technical measures can be put forward from the two aspects of inter-harmonic excitation source suppression and polygon wear feedback suppression, comprehensive suppression of development of polygon wear of the wheel is achieved, polygon wear of the wheel caused by electrical parameters is reduced, and the method has the advantages of being low in implementation cost and not prone to being affected by the external environment.

The invention relates to a control method for a parallel active power filter based on harmonic voltage suppression, and belongs to the technical field of power control. Three-phase power grid voltages are respectively obtained through a sensor, and a compensation current instruction of each selected subharmonic of each phase is calculated and determined through a second-order band-pass filter bank of selected subharmonic; determining an instantaneous value instruction of the compensation current of each selected subharmonic of each phase according to the transfer function, summing the instantaneous value instruction of the compensation current of each selected subharmonic corresponding to each phase, determining a total instruction of the selected subharmonic of each phase, and sending the total instruction to a current control loop; and the current control loop modulates and drives the voltage type inverter through the PWM driving module, so that the compensation current waveform formed by the voltage type inverter is consistent with the total instruction current waveform, and the compensation current is input to the power grid. The safety and stability of the harmonic suppression process are improved.

The utility model discloses a wiring cabinet of an active power filter. The wiring cabinet comprises a cabinet door; the front surface of the cabinet body is connected with the side wall of the cabinet door through a hinge; the side wall of the placing plate is in sliding connection with the inner wall of the cabinet body; the filter is located at the top of the placement plate; one side, far away from the filter, of the placing plate is rotationally connected with the elliptical plate; the adjusting device is positioned at the bottom of the placing plate; the utility model relates to the technical field of filter wiring cabinets, the device can easily realize the height adjustment of a filter through the adjusting device, the operation is convenient, the elliptical disc can rotate to drive the sliding plate to move only through the simple steps of pushing the rotating handle, rotating the push-pull rod and the like, and the operation is convenient. The clamping rods are separated from the clamping grooves, so that the height of the placing plate is adjusted.

The application relates to the technical field of power electronics and harmonic treatment, and discloses a hybrid active power filter topology and an operation control method thereof. The topology comprises two sets of AC filters, two sets of three-phase cascaded half-bridge sub-module valve groups and one set of three-phase cascaded full-bridge sub-module valve group. The first ends of the two sets of AC filters are connected with a high-voltage bus, and the tail ends are connected with corresponding electrical nodes respectively. The first ends of the two sets of three-phase cascaded half-bridge sub-module valve groups are connected with different electrical nodes respectively, and the tail ends are connected with the ground respectively. The first end and the tail end of the three-phase cascaded full-bridge sub-module valve group are connected with two groups of electrical nodes respectively, forming a bridging structure. The nine-switch topology design can realize the functions of the traditional two sets of valve groups by only one set of valve group, thereby significantly reducing the system cost and the floor area. In combination with the double strategies of impedance control and current control, the control precision and the anti-interference ability are improved, the conventional DC power transmission system characteristic harmonic can be filtered efficiently, and the application value in engineering is high.

The application discloses a harmonic distributed treatment method based on a self-learning algorithm, and belongs to the field of harmonic treatment of distribution networks. The method adopts a voltage detection active power filter (VDAPF) to treat harmonics, and the key to distributed treatment of a "double-high" distribution network is proposed. The application proposes a method for quantifying the global treatment effect and the degree of participation of VDAPF in collaborative treatment, respectively, to obtain a preliminary performance factor. The preliminary performance factor is converted into a final performance factor based on a self-learning algorithm, and the local control G-U lifting adjustment characteristics of the VDAPF are combined to realize self-organizing distributed optimization of treatment equipment in a distributed treatment system. The harmonic distributed treatment method based on the self-learning algorithm can solve the problem that scattered treatment is not applicable due to the intensification and decentralization of harmonic sources, and can change passive harmonic treatment into active harmonic treatment.

The invention belongs to the technical field of regional power grid electric energy quality treatment, and discloses a cross-power-grid harmonic resonance suppression method, system and device and a medium, and the method comprises the steps: deploying an active filter, and executing local harmonic treatment; on the basis of a local harmonic suppression result, the operation state of the active filter is evaluated, the residual capacity of the flexible resources in the regional power grid is called, and a cooperative harmonic suppression mechanism for cooperative work of the active filter and the flexible resources is constructed; and synchronously executing local harmonic suppression and collaborative harmonic suppression mechanisms, monitoring the total harmonic distortion rate of the regional power grid in real time, performing iterative optimization adjustment on the installation position and capacity of the active filter by using a particle swarm optimization algorithm, and outputting an optimal suppression scheme. According to the invention, through optimizing the harmonic suppression strategy, the total harmonic distortion rate of the power system is reduced, so that the harmonic suppression effect is improved; and a chance constraint method is adopted to ensure that the method has good robustness and adaptability under different power grid operation conditions.

A capacitance compensation cabinet with an active power filter (APF) function comprises a cabinet body, the cabinet body is sequentially provided with a cabinet top main bus chamber, a main switch chamber, a capacitor reactor installation chamber and an APF module installation compartment from top to bottom, the cabinet top main bus chamber is internally provided with a lap-joint bar penetrating through other chambers, the main switch chamber is provided with a circuit breaker, and the APF module installation compartment is provided with an APF module. The circuit breaker is electrically connected with the lap joint bar, an active power filter (APF) module is arranged in the APF module installation compartment and is electrically connected with the lap joint bar, a plurality of capacitors and reactors are arranged in the capacitor reactor installation chamber, a branch busbar is arranged at the output end of the circuit breaker and is connected with a plurality of fuses, and the branch busbar is electrically connected with the fuse. Each fuse is connected with a corresponding combination switch, and each combination switch corresponds to a group of reactors and capacitors.

The invention relates to a self-adaptive prediction control method and system for an LCL type active power filter, and the method comprises the following steps: introducing a self-adaptive weight, dynamically fusing a power supply current frequency domain detection component and a load current time domain detection component, and fusing frequency domain high-precision detection and time domain quick response detection through the self-adaptive weight. The limitation of a single detection mode is overcome, and the compensation precision and the response speed can be improved respectively under the steady-state and transient-state working conditions; the reference current is predicted in advance according to the digital control delay step size, an inverter voltage instruction is calculated in a reverse recursive mode according to the reference current, the inverter voltage instruction is corrected to obtain a final instruction, and the final instruction drives a voltage source inverter to output compensation current; according to the compensation current tracking error and the load power change rate, the self-adaptive weight, the outer ring prediction step length and the self-adaptive virtual damping coefficient are dynamically adjusted, and the overall adaptability of the system to complex working conditions is enhanced.

This utility model relates to the field of active power filter technology and provides an active power filter device, comprising: a current transformer connected between the mains power supply and the load for acquiring three-phase current signals; an active power filter whose input terminal is connected between the mains power supply and the current transformer, and whose current transformer interface is connected to the current transformer; the active power filter includes a control board and a display module; the control board is connected to the input terminal and is used to acquire the three-phase voltage signal of the power grid through the input terminal, acquire the three-phase current signal through the current transformer interface, and generate a connection anomaly detection signal for the current transformer based on the three-phase voltage signal and the three-phase current signal, and send a flag bit signal corresponding to the connection anomaly detection signal to the display module. This solves the problem of quickly and accurately providing a connection anomaly detection signal for the external current transformer of the active power filter.

The invention discloses a network construction type high-precision active power filter control method, an active power filter comprises a power outer loop control unit and a voltage and current inner loop control unit, and the power outer loop control unit comprises an active power outer loop and a reactive power outer loop. The voltage and current inner loop control unit comprises an AC voltage loop and an AC current loop, and the control method provides a control loop architecture for three-phase three-wire and three-phase four-wire high-precision active power filters, and comprises two-phase DQ closed-loop control and three-phase independent closed-loop control of grid-side harmonic current; through a mode of generating a harmonic voltage instruction through a harmonic current closed loop, the impedance of a harmonic current frequency band is remodeled while high-precision compensation of the harmonic current is realized; high-precision compensation of harmonic current is realized through a network construction control technology; while high-precision compensation is realized, port harmonic impedance is remodeled, so that the adaptability of a load and a power grid is higher.

This invention relates to a current transformer (CT) installation circuit with an active power filter (APF) and a method for determining the CT position. The circuit includes a load terminal, a power supply terminal, an active power filter (APF), a capacitor, and a current transformer. A first circuit connects the load terminal and the power supply terminal, and a second circuit extends from the first circuit, connecting to the active power filter. A capacitor circuit is connected in parallel to the first circuit, with the parallel connection positions of the capacitor circuit including the power supply side and the load side. The current transformer is installed on the first circuit relative to the parallel connection positions of the capacitor circuit. This invention considers the CT installation position in conjunction with the capacitor circuit installation. Since the capacitor circuit generates reactive power, connecting it in parallel in the circuit can compensate for the reactive power consumed by the inductive load, thereby increasing voltage and improving the power factor. Combining the CT installation position with the capacitor circuit effectively ensures the overall reactive power compensation effect of the circuit under different conditions.

The invention discloses an active filtering and reactive compensation adaptive control method, and belongs to the technical field of rail transit power systems. The method comprises the steps that S1, real-time monitoring is conducted, an active power filter (APF) is connected into a power grid and controlled by a DSP controller to be switched between an operation mode and a shutdown mode, and the DSP controller is electrically connected with a communication interface; s2, condition monitoring is triggered, switching between an operation mode and a shutdown mode is achieved, and the switching modes comprise automatic switching according to the rail transit operation time period and remote switching by receiving an instruction through a communication interface of a DSP controller; s3, dual-mode purification of electric energy quality: in an operation mode, an active power filter APF starts a harmonic compensation function and dynamically tracks a target power factor in a reactive mode; and in the shutdown mode, the active power filter APF closes the harmonic compensation function and outputs fixed inductive reactive power. The operation time period of the rail transit is matched with the two modes of the active power filter APF, so that the self-adaptive control of the electric energy quality can be realized according to the operation condition of the rail transit.

The utility model relates to active power electronic filter and power electronic technical field discloses a kind of active power filter based on high-power IGBT single tube parallel driving, including multisignal fusion detection module, DSP control module, drive control module, IGBT power bridge arm module, auxiliary power module, support module and LCL filter module, the DSP control module is electrically connected with drive control module and support module respectively, the drive control module is electrically connected with IGBT power bridge arm module, the output end of switching power supply is electrically connected with the input end of multisignal fusion detection module, the IGBT power bridge arm module is electrically connected with LCL filter module.The utility model in, by adopting the design of IGBT single tube parallel, unnecessary intermediate connecting piece is reduced, equipment volume is effectively reduced, the problem such as the space occupancy big and installation inconvenience caused by complex structure is solved.

The invention discloses a three-level active power filter direct-current bus capacitor design method and system, and belongs to the field of power electronic device design, and the method comprises the steps: determining the minimum capacity demand of a direct-current bus capacitor according to the rated power of a system and the working condition of a power grid; respectively calculating effective values of the triple frequency ripple current and the high-frequency ripple current related to the switching frequency by adopting a decomposition analysis method of a low-frequency component and a high-frequency component; by decomposing the low-frequency ripple current and the high-frequency ripple current, a ripple current mathematical model is established to analyze the bearing capacity of the capacitor for ripple current of different frequencies, and model selection and parallel configuration of the capacitor are obtained; carrying out the structure and heat dissipation design of the capacitor; evaluating the service life of the capacitor, and designing a maintenance mechanism in combination with a service life evaluation result; simulation verification is carried out, the current ripple control effect is tested firstly, and then the system stability is verified. The method optimizes the parallel configuration of the capacitors, and improves the dynamic response performance and long-term operation reliability of the system.

This application relates to a multi-pulse rectifier power supply device and its control method, apparatus, and power supply system. The method includes: determining a first reactive current reference value that needs to be injected into the point of common coupling (PCC) of an active power filter based on the actual output power value and a reference output power value of the multi-pulse rectifier; determining a control signal for the active power filter based on the first reactive current reference value; and controlling the active power filter according to the control signal to inject the target current into the PCC. This method enables regulation of the output power of the multi-pulse rectifier, thereby improving the reliability of the power supply device.