15results about How to "Suppressed circulation" patented technology

The invention discloses a carrier synchronization method and device, an inverter and a storage medium, and relates to the technical field of carrier control, and the method comprises the steps: transmitting a host competition signal to a carrier bus in a system when a slave inverter in an inverter parallel system cannot acquire a carrier signal transmitted by a master inverter in the system and reaches a first preset duration, and then transmitting the host competition signal to the carrier bus in the system; all slave inverters in the system respond to the host competition signal to send a first identification number to the bus, and monitor a bus identification number transmitted in the bus at the same time, when a certain slave inverter finds that the first identification number sent by the slave inverter is matched with the bus identification number, it is confirmed that host competition succeeds, and the slave inverters send the first identification number to the bus. The main inverter sends carrier signals to the bus, the other slave inverters acquire the carrier signals to perform carrier synchronization, and the slave inverters establish a master-slave structure of the system through competition of the host, so that the carrier synchronization function of the system is established or recovered, the carrier synchronization stability of the system is improved, and the circulating current of the system can be efficiently inhibited.

The embodiment of the invention relates to the technical field of electric power, in particular to a converter control circuit, a converter and a charging pile. The converter control circuit and the converter comprise the coupling unit, the power conversion unit, the bus unit and the control unit, one path of input of alternating current is converted into two paths or multiple paths of output by additionally arranging the coupling unit, in the multiple paths of output, current is isolated and equally divided, and the output current of the power conversion unit is improved. Meanwhile, the internal structure of the coupling unit suppresses the circulating current in the converter, and the circulating current loss in the power conversion unit is reduced. Furthermore, the power conversion unit is provided with a plurality of T-shaped three-level inversion units, so that a multi-level technology is realized, multi-voltage level is provided, and multi-level output can remarkably reduce harmonic content of output voltage and current, reduce current ripples and improve electric energy quality.

The invention discloses a control method, device and equipment for a three-level interleaving direct-current converter, and relates to the technical field of power electronics, and the method comprises the steps: determining a voltage-sharing control compensation value of a high-voltage side and a current-sharing control compensation value of each phase according to a control sampling parameter of an n-phase three-level interleaving direct-current converter; determining two modulation signals corresponding to each phase according to the voltage-sharing control compensation value and the current-sharing control compensation value of the high-voltage side; determining an upper unit switch tube driving signal and a lower unit switch tube driving signal of each phase in the n-phase three-level interleaved parallel DC converter according to two phase shift signals of each phase and two modulation signals of each phase corresponding to the input carrier signal, so as to control switch tubes in respective upper units and lower units of n three-level bridge arms in the converter; according to the invention, the non-voltage-sharing condition of the high-voltage side capacitor of the converter can be conveniently suppressed, the circulating current of the converter is suppressed, and the output current balance degree of each phase is improved, so that the precision and stability of the system are improved.

The application belongs to the technical field of battery management, and discloses a parallel battery cooperative control method and system based on a communication bus. The method adopts a decentralized architecture, each battery module periodically broadcasts its own information containing MOS state semantics through the communication bus, and receives other information; each module autonomously decides the switch of the charging and discharging MOS based on a preset rule. The core innovation includes: the MOS closed state is semantically classified into protection closed, logic closed and other types, precise cooperation is realized; a channel giving mechanism is introduced, so that the recovery process after protection is removed has no circulating current; in the discharging state, the braking signal and voltage judgment are combined to intelligently control the feedback current absorption; each module assigns an ID by broadcasting a unique code, supporting hot plug. The application completely eliminates the single-point fault of the traditional scheme, significantly improves the reliability, expandability, safety and energy efficiency of the parallel system, and is suitable for electric vehicles, energy storage devices and other fields.

The application discloses a fair and sequential model predictive control multi-objective optimization method for a parallel T-type three-level rectifier, and aims at solving the problems of power distribution, midpoint voltage balance, circulating current suppression, DC voltage stability and grid current tracking in a parallel T-type three-level rectifier system in a high-power rectifier occasion. The application adopts double closed-loop control, the outer ring adopts adaptive droop control with voltage feedforward, realizes the stability of DC voltage and load power distribution, the inner ring adopts fair and sequential model predictive control, through the fair priority order, not only the advantage that the sequential model predictive control does not need to select a weight factor is reserved, but also the problem that the optimal solution cannot be selected due to the fixed priority order of the sequential model predictive control is solved, the balance of the midpoint voltage, the circulating current suppression and the tracking of the grid current are realized, and the overall scheme realizes the multi-objective optimization control of the parallel system.

This invention relates to the field of wind turbine grid construction control technology, and particularly to a method, system, equipment, and medium for multi-unit collaborative grid construction control of offshore wind farms based on virtual impedance control. The method includes: acquiring initial parameters of virtual resistance and virtual inductance in the virtual impedance control loop; acquiring and preprocessing the output current of the grid-side converter, converting the preprocessed output current to a rotating coordinate system to obtain orthogonal axis current components; separating and extracting the fundamental and non-fundamental components of the output current; determining the presence of power oscillation in response to the non-fundamental component exceeding a preset non-fundamental current threshold, calculating the ratio of the fundamental to non-fundamental components to obtain virtual impedance parameter correction, and adaptively correcting the initial parameters of virtual resistance and virtual inductance; inputting the orthogonal axis current components into the virtual impedance control loop, calling the corrected virtual resistance and virtual inductance parameters, and calculating the orthogonal axis voltage correction.

The present invention relates to the field of power electronics technology, and specifically to a cascaded 24-pulse converter topology, including a dual Y pulse generator, a phase-shifting transformer group, a four-quadrant 24-pulse converter group and a resistive-inductive load, wherein the dual Y pulse generator is connected to one end of the phase-shifting transformer group, the other end of the phase-shifting transformer is connected to one end of the four-quadrant 24-pulse converter group, and the other end of the four-quadrant 24-pulse converter group is connected to the resistive-inductive load. The device can effectively suppress circulating current, eliminate the need for an external circulating current reactor, save costs, and reduce volume. Once a converter fault occurs and the circulating current is out of control, it will only affect the converter connected in parallel with the fault converter, and will not affect the remaining converters, thereby protecting the other converters to the maximum extent; four-quadrant operation can be achieved; the connection method between the transformer and the converter makes the grid side and the transformer load balanced, the transformer load is small, and the circulating current will not flow through the two secondary sides of the same transformer at the same time.

The utility model relates to the technical field of power distribution networks, and discloses a structure for preventing a large-current conductor from passing through a roof to generate circulating current, which comprises an installation structure, the installation structure comprises a connecting piece and at least three installation pipes passing through the roof, the connecting piece is made of non-magnetic materials, steel bars are provided with gaps, and the connecting piece is fixed on the steel bars and communicated with the gaps. The mounting pipe is fixed to the supporting framework, and the concrete is filled on the periphery of the mounting pipe and wraps the connecting pieces, the steel bars and the mounting pipe. Non-magnetic connecting pieces are adopted to replace steel bars to be connected between the mounting pipes, electromagnetic fields around the cables are effectively isolated, the three-phase cables are prevented from forming closed loops respectively, the three-phase cables are made to be located in the same closed loop, and therefore current circulation is restrained, electromagnetic induction is reduced, and the heat effect between a split-phase bus and the steel bars is reduced; and therefore, the waterproof performance and the structural strength of the roof are prevented from being influenced by cracks of the roof caused by bursting of the concrete due to heating.

This invention discloses a method, system, controller, and medium for suppressing unbalanced MMC circulating current, relating to the field of MMC control. The method includes: acquiring three-phase voltage parameters, three-phase current parameters, and grid angular frequency of the MMC; performing phase sequence decomposition on the three-phase voltage parameters, three-phase current parameters, and grid angular frequency to obtain the positive-sequence and negative-sequence components of the three-phase voltage and three-phase current; using a PI controller to perform inner-loop regulation on the positive-sequence and negative-sequence components of the three-phase voltage and three-phase current, outputting the positive-sequence and negative-sequence reference components of the three-phase voltage in a synchronous rotating coordinate system; performing inverse transformation of the positive-sequence and negative-sequence reference components of the three-phase voltage according to the grid angular frequency, and adding the results of the inverse transformation to obtain the three-phase voltage reference components; performing carrier phase-shift modulation on the three-phase voltage reference components to generate the port levels required for each phase arm, and controlling the operating state of the IGBTs in each phase arm submodule of the MMC based on the port levels.

The utility model relates to the technical field of batteries, in particular to a power supply device which comprises a first battery module, a second battery module, a control module and a switching module, and the second battery module and the first battery module are connected in parallel; the control module can detect the voltage of the first battery module and the voltage of the second battery module; the switching module is respectively connected with the first battery module, the second battery module, the control module and the load module, and responds to the first control signal to control the first battery module to charge the second battery module; the switching module responds to the second control signal to control the second battery module to charge the first battery module. Circulating current in the power supply device can be suppressed to at least a certain extent.

The present invention discloses a cascaded staggered totem pole bridgeless PFC device and its control strategy. The device belongs to the field of power electronics technology. The cascaded staggered totem pole bridgeless PFC device specifically includes 2 power frequency bridge arms, 4 high frequency bridge arms, 2 boost inductors and 2 filter capacitors. Among them, the midpoints of the two power frequency bridge arms are respectively connected to the two ends of the AC power supply, and the high frequency bridge arms between the upper and lower paths are connected through the boost inductor. A control strategy proposed based on this device includes two PWM modulation strategies: voltage equalization control, current equalization control, and carrier phase shift and level shift. The technical effects of reducing inductance volt-seconds, reducing input current ripple and suppressing common mode noise can be achieved; and when the capacitance values ​​of the two output filter capacitors are not equal or the load sizes are inconsistent, the circuit can still achieve the control goals of equal output voltage and equal current.

The invention provides an inter-cluster circulating current suppressor for battery clusters of an energy storage system and a control method of the inter-cluster circulating current suppressor. The circulating current suppressor comprises n groups of battery clusters which are connected in parallel, n bidirectional DC / DC converters P1-Pn, an isolation power supply PU and a circulating current controller CZ. The positive electrodes of the A ports of P1-Pn are electrically connected with the n groups of battery clusters in a one-to-one correspondence manner, and the negative electrodes of the A ports of P1-Pn are jointly connected to a common bus DCbus-; the output end of the PU is in positive and negative connection with B ports of P1-Pn, the positive electrode of the input end of the PU is connected to a common bus DCbus +, and the negative electrode of the input end of the PU is connected to a common bus DCbus-; and one connecting end of the CZ is respectively connected to P1-Pn, and the other connecting end of the CZ is connected to a common bus DCbus +. According to the invention, the output current of each battery cluster can be dynamically adjusted, so that the output current of each battery cluster is kept in an error allowable range, thereby realizing the equalization of each battery cluster and achieving the purpose of restraining the circulating current.

The invention discloses an energy router coordination control system, method and device and a medium, and relates to the technical field of direct current distribution networks, and the energy router coordination control system comprises an I-path AC 10 kV and an II-path AC 10 kV; the I-path AC10kV is connected to the power adapter 1, one end of the output end of the power adapter 1 is connected to the DC750V bus, and the other end of the output end of the power adapter 1 is connected to the dual-power quick change-over switch 2; the path II AC10kV is connected to a box transformer substation 3, one end of the output end of the box transformer substation 3 is connected to an AC-DC converter 4, the other end of the output end of the box transformer substation 3 is connected to a dual-power quick change-over switch 2, and a 500kW converter 4 is connected to a DC750V bus; and the dual-power quick change-over switch 2 is connected to an AC 380V bus. By introducing a dynamic virtual impedance adjusting mechanism, the circulating current problem in parallel operation is effectively suppressed, and the stability of bus voltage and power distribution is improved.

The invention discloses a modulation method for a parallel converter, establishes a parallel converter mathematical model, determines a basic voltage vector and a space voltage vector plane; divides the space voltage vector plane into 6 large sectors, selects a basic voltage vector with a zero-sequence circulating current change rate of ‑1~+1 in each large sector, determines 8 switch timings based on the principle of minimum switching times, divides the large sector into 8 sub-sectors corresponding to 8 switch timings based on the principle of minimum voltage synthesis error, and obtains 48 optimal switch timings covering the entire space voltage vector plane; calculates the three-phase switch duty ratio based on the vector synthesis principle and the switch timing, and normalizes the three-phase switch duty ratios of the 48 sub-sectors; tracks the change of the zero-sequence circulating current of the parallel converter to optimize the three-phase switch duty ratio, synthesizes a modulation wave based on the optimal switch timing, and generates a PWM signal to control the on-off of the switch tube of the parallel converter after comparison with the carrier, and completes the modulation. The invention improves the efficiency of the parallel converter.

This invention belongs to the field of AC / DC hybrid distribution network operation and control technology. A method for autonomous and mutual-assistance operation of AC / DC hybrid distribution networks based on flexible multi-state switches includes the following steps: Step S1: Calculate the comprehensive stability index of each node; Step S2: Monitor the comprehensive stability index in real time; Step S3: In the autonomous mode, the SOP within each zone adopts an AC / DC power decoupling control strategy based on dynamic virtual impedance; Step S4: When the power deficit of a zone exceeds a preset proportion of the zone's rated load and the duration exceeds a preset time threshold, the mutual-assistance mode is activated; Step S5: When a system fault occurs, a fault recovery strategy based on model predictive control is adopted; Step S6: Monitor the communication status between the global coordination unit and the control units of each zone in real time. This achieves safe, stable, efficient, and economical system operation, reduces communication dependence, and improves power supply reliability.