88results about "Active power filtering" 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.

Systems and methods for supplying power (both active and reactive) at a medium voltage from a DCSTATCOM to an IT load without using a transformer are disclosed. The DCSTATCOM includes an energy storage device, a two-stage DC-DC converter, and a multi-level inverter, each of which are electrically coupled to a common negative bus. The DC-DC converter may include two stages in a bidirectional configuration. One stage of the DC-DC converter uses a flying capacitor topology. The voltages across the capacitors of the flying capacitor topology are balanced and switching losses are minimized by fixed duty cycle operation. The DC-DC converter generates a high DC voltage from a low or high voltage energy storage device such as batteries and / or ultra-capacitors. The multi-level, neutral point, diode-clamped inverter converts the high DC voltage into a medium AC voltage using a space vector pulse width modulation (SVPWM) technique.

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.

A hybrid uninterruptible power supply includes a power conversion unit including a converter electrically connected to a first external alternating current (AC) power source, an inverter electrically connected to an output of the converter and to a load, and a power storage unit electrically connected between the converter and the inverter, a current thrupass unit electrically connected to the first external AC power source and electrically connected to the load and including a first thyristor, a current bypass unit including a second thyristor and a switch electrically connected in parallel to the second thyristor, the second thyristor being electrically connected to a second external AC power source and electrically connected to the load, and a controller configured to control the power conversion unit, the current thrupass unit, and the current bypass unit.

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.

Techniques are described for testing whether an end effector, or component thereof, is correctly or incorrectly installed to a manipulation system. In an example, a manipulation system can include a manipulator arm configured to receive an end effector having a first moveable jaw, a transducer configured to provide first effort information of the end effector as the end effector moves, and a processor configured to provide a command signal to effect a first test move of the first moveable jaw, and to provide an installation status of the of the end effector using the first effort information of the first test move.

Techniques are described for testing whether an end effector, or component thereof, is correctly or incorrectly installed to a manipulation system. In an example, a manipulation system can include a manipulator arm configured to receive an end effector having a first moveable jaw, a transducer configured to provide first effort information of the end effector as the end effector moves, and a processor configured to provide a command signal to effect a first test move of the first moveable jaw, and to provide an installation status of the end effector using the first effort information of the first test move.

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.

This invention provides a control method for the active section of a hybrid power active filter. By employing a three-phase fictitious and improved symmetrical component method, it can perform electrical quantity calculations under severely asymmetrical three-phase nonlinear load conditions, extracting the zero-sequence current component, which contains zero-sequence harmonic currents. Furthermore, due to the use of a triangular wave comparison control method, the resulting PWM pulse signal contains fewer harmonics. Using this PWM pulse signal to control the active section of the hybrid power active filter enables effective control and accurate filtering of zero-sequence harmonic currents. In summary, the control method of this invention enables the hybrid power active filter to accurately filter zero-sequence harmonic currents under severely asymmetrical three-phase nonlinear load conditions, achieving an ideal filtering effect.

The utility model discloses power electronics equipment's test and debugging technical field relates to a kind of debugging device for active filter;Including cabinet;The cabinet inside is provided with voltage regulator, control module and power module;The control module is located above voltage regulator;The cabinet side is provided with aviation plug;The power module and voltage regulator are electrically connected;The voltage regulator and aviation plug are electrically connected;The aviation plug is electrically connected with active filter and control module respectively;The active filter and mutual inductor are electrically connected;The mutual inductor and control module are electrically connected;The voltage regulator and intelligent electric meter are electrically connected;The intelligent electric meter and control module and electrically connected.The utility model can realize the quick power-on test of active filter, parameter adjustment and performance verification.

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 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.

A cascaded multilevel converter is disclosed. The converter comprises a plurality of modules coupled together to form a branch, each of the modules comprising a switching circuit and a DC link for supplying a DC voltage to the switching circuit. The converter further comprises a controller for controlling the switching circuit of each module to generate an AC voltage in the branch, wherein the controller is configured to: determine, for each module, a voltage across a capacitor of the DC link of the module; determine, for each module, a reference power value for charging the capacitor of the DC link of the module to a reference voltage value for the module; determine, from the reference power values of the modules, a common reference AC current value for AC current in the branch; and determine, from the common reference AC current value, a common reference AC voltage value for an AC voltage in the branch.

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 provides a reverse time-lag overcurrent relay protection regulation method and system, comprising: when the system resonates based on the outlet current monitoring of the APF: based on the pre-constructed optimal relay protection action table, the APF of the optimal relay protection action value is cut off; continue to monitor the outlet current of the APF, if the current harmonic content is less than the action value but the power grid quality does not meet the set power supply quality requirement, based on the power quality requirement in the micro grid, the active damping control is added in the selected APF. When the micro grid island APF parallel system operation resonates, first, the connection between the APF and the large power grid is cut off by the reverse time-lag overcurrent relay protection to suppress the inter-machine resonance, then the active damping control is added to improve the system power quality, the problem that the phase deviation exists between the LCL type APF output compensation current and the detection current is solved, the system loss is reduced, the effective suppression of the APF parallel inter-machine resonance is realized, and the power quality is improved.

The application discloses a control method and system of a hybrid active power filter and a storage medium, wherein the inductance value and the capacitance value of a passive power filter are taken as inputs of a particle swarm optimization method to obtain optimized inductance value and capacitance value; when the harmonic number filtered by the passive power filter is the same as the harmonic number filtered by the active power filter, the active power filter is equivalent to a virtual LC filter with the same structure as the passive power filter; otherwise, the active power filter is equivalent to a virtual resistor; a harmonic compensation current reference value of the active power filter is obtained; the harmonic compensation current reference value and a reactive compensation current reference value are superimposed to obtain a total reference current of the active power filter, and the total reference current is taken as an input of a proportional resonant controller, and the output of the proportional resonant controller is PWM modulated. The application eliminates the harmonic current amplification problem of the passive power filter and improves the stability and compensation performance of the power system.

Techniques are described for testing whether an end effector, or component thereof, is correctly or incorrectly installed to a manipulation system. In an example, a manipulation system can include a manipulator arm configured to receive an end effector having a first moveable jaw, a transducer configured to provide first effort information of the end effector as the end effector moves, and a processor configured to provide a command signal to effect a first test move of the first moveable jaw, and to provide an installation status of the end effector using the first effort information of the first test move.

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.

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 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.

The utility model provides a wall-mounted hybrid APF device, which relates to the technical field of hybrid APF devices, and comprises a wall and a fixed plate fixedly mounted on the wall, an L-shaped sliding block is arranged in the fixed plate, a mechanism used for adjusting the L-shaped sliding block is arranged in the fixed plate, a group of mounting grooves are formed in the top end of the L-shaped sliding block, and the L-shaped sliding block is arranged in the mounting grooves. And one side of the L-shaped sliding block penetrates through the sliding groove to be provided with a device body, one side of the device body is connected and provided with a set of L-shaped connecting plates, the set of L-shaped connecting plates are installed in the set of installing grooves, and connecting structures are arranged at the attaching positions of the L-shaped connecting plates and the installing grooves. According to the device, the height of the device body can be adjusted according to the needs of workers, the connecting efficiency of the device body and external elements is indirectly improved, inconvenience brought to the workers by height fixation is avoided, the workers do not need to adjust the height of the device body to frequently open holes in the wall for installation, and the installation efficiency is improved. And due to the design, the practicability is greatly improved.

The invention discloses a multi-set parallel coordinated control method and device for active power filtering devices, and the method comprises the steps: obtaining a control target voltage / current; according to the control target voltage / current, a harmonic current instruction is obtained through closed-loop control, and a clock synchronization signal is obtained according to the real-time phase of the bus voltage; obtaining a harmonic current sub-instruction corresponding to each active power filtering device according to the harmonic current instruction; and controlling each active power filtering device to synchronously output harmonic current according to the harmonic current sub-instruction and the clock synchronization signal. According to the invention, the problem of unbalanced output caused by scattered sampling and open-loop control when multiple sets of active power filtering devices are operated in parallel can be improved.

This application discloses an extended harmonic mitigation closed-loop harmonic compensation method, device, terminal, and medium. The technical solution provided in this application uses an APF installed in the local transformer substation to obtain current information from adjacent transformer substations to achieve extended harmonic compensation. This solution eliminates the need for time-frequency transformation of the sampled data of aliased harmonics at the measurement point before communication transmission. Instead, it directly packages and transmits the time-domain current waveform output, thereby achieving equivalent remote sampling and synchronous closed-loop control of analog signals on the harmonic compensation device. Harmonic compensation is achieved directly without time-frequency transformation at the measurement terminal, thus achieving high-bandwidth harmonic closed-loop suppression. Essentially, it realizes the equivalent extension of the harmonic current sampling line and its analog signal sampling line, enabling the APF installed in the local transformer substation to perform real-time closed-loop compensation of the harmonic current of adjacent transformer substations.

The present application relates to the technical field of active power filter, and provides a power harmonic treatment method and a single-phase full-bridge combined active power filter, the method comprising: acquiring a grid voltage, an actual DC bus voltage, a load current and an actual compensation current injected into the grid by the active power filter; calculating a target compensation current in real time according to the grid voltage, the actual DC bus voltage, the load current and the actual compensation current; calculating a control quantity of a DC bus voltage outer loop and a reference quantity of a current inner loop control through a system closed-loop control algorithm; calculating a sinusoidal pulse width modulation instruction signal through the system closed-loop control algorithm; and controlling the active power filter to inject the target compensation current into the grid according to the instruction signal. The present application injects the target compensation current into the grid to offset the harmonic current generated by a nonlinear load, so that the grid current remains a sinusoidal wave and prevents harmonic pollution of the grid.