55results about How to "Power sharing" patented technology

The invention discloses a carrier power sharing method in a multi-carrier cell, which comprises the following steps: when determining that the cell supporting carrier power share adopts a dynamic carrier power sharing function, determining the initial configuration power of each carrier in the cell through a Node B by detecting the power; in each preset measurement period, calculating the proportion of the average power of the carriers to the initial configuration power, and calculating the surplus power percentage according to the acquired proportion; and the first carrier of which the surplus power percentage is smaller than a preset first threshold shares the surplus power of the second carrier of which the surplus power percentage is greater than a preset second threshold. The method can increase the utilization rate of cell power.

The invention provides an auxiliary current transformer and a control method thereof. The auxiliary current transformer comprises an input switch pre-charging unit, an input filtering unit, a preceding voltage increasing unit, two middle frequency isolation DC/DC current transformers, a three-phase inversion unit, an output filtering unit and an external output control unit. The input switch pre-charging unit comprises two pre-charging resistors. The pre-charging resistors are serially connected or parallelly connected with each other. The preceding voltage increasing unit comprises two paths of boost voltage increasing modules. The boost voltage increasing modules are serially connected or parallelly connected with each other. The middle frequency isolation DC/DC current transformers are connected with the boost voltage increasing modules and used for carrying out middle frequency inversion on direct current voltage output by the boost voltage increasing modules to generate middle frequency square-wave voltage and carrying out isolation voltage transformation on the middle frequency square-wave voltage and rectifying the middle frequency square-wave voltage into direct current voltage. The middle direct current voltage output by the middle frequency isolation DC/DC current transformers are parallel connected and then input into a three-phase inversion unit.

The invention discloses a seamless switching control system and method based on a hybrid control strategy. The system and method can realize automatic switching from current source control to voltage source control based on droop control of an inverter when switching from grid-connected operation to isolated island operation, thereby improving load voltage quality in the process of switching from a grid-connected mode to an isolated island mode. Slave inverters are divided into two kinds, wherein the first kind of slave inverters are based on conventional PQ control and adopt current source control, and are named as slave inverters-type 1; and the other kind of slave inverters are based on PQ control and droop control, and are named as slave inverters-type 2. When island occurs, the slave inverter-type 2 is switched from the PQ control to the droop control and operates in a voltage source mode, and can realize power equalization without fast communication lines; and the slave inverter-type 2 can serve as a main inverter after switching to the droop control, thereby playing a role in maintaining grid voltage amplitude and frequency stability. Existence of a plurality of main inverters enhances reliability of a micro-grid system during isolated island operation.

The invention discloses a control method for an aging power supply device, and belongs to the field of power electronic system control. The method comprises a control method of a single-phase AC/DC converter circuit, an open-loop control method adopted by an LLC resonant converter, and a control method of a bidirectional BUCK-BOOST converter circuit. Through the control method of the single-phaseAC/DC converter circuit, the DC bus voltage is kept constant, fluctuation of the power grid frequency and distortion of the grid connection current at the non-fundamental frequency are suppressed, andharmonic pollution to the power grid is reduced. Through the adoption of the open-loop control method, the series LLC resonant converter can work in an intermittent mode, the switching loss of the circuit is reduced, and meanwhile, the requirement of boosting between a direct-current bus and the input of the BUCK-BOOST converter circuit is also met. Through the control method of the bidirectionalBUCK-BOOST converter circuit, power sharing by a host and a slave in a constant-current mode is realized, switching tube driving signals of two BUCK-BOOST converters are subjected to phase shifting by 180 degrees to realize interleaved parallel connection, ripples of the current on the output side are reduced, and the quality of the output current is improved.

The invention relates to a low polarization dependent loss lithium niobate straight-bar waveguide phase modulator and a manufacturing method of the low polarization dependent loss lithium niobate straight-bar waveguide phase modulator. The low polarization dependent loss lithium niobate straight-bar waveguide phase modulator comprises a lithium niobate optical waveguide chip, a first polarization-maintaining pigtail assembly and a second polarization-maintaining pigtail assembly, wherein the first polarization-maintaining pigtail assembly and the second polarization-maintaining pigtail assembly are bonded to the two ends of the lithium niobate optical waveguide chip in a coupling mode respectively, the lithium niobate optical waveguide chip comprises a lithium niobate substrate, a titanium diffusion waveguide area, annealing external diffusion areas and metal electrodes, an x-cut y-pass chip is adopted for the lithium niobate substrate, the titanium diffusion waveguide area and the annealing external diffusion areas are arranged on the surface layer of the lithium niobate substrate, the annealing external diffusion areas are arranged on the two sides of the titanium diffusion waveguide area respectively, the metal electrodes are arranged on the surfaces of the annealing external diffusion areas, the positive electrode and the negative electrode are symmetrical about the titanium diffusion waveguide area, and the first polarization-maintaining pigtail assembly and the second polarization-maintaining pigtail assembly respectively comprise a first polarization-maintaining optical fiber and a first optical fiber fixing block. The low polarization dependent loss lithium niobate straight-bar waveguide phase modulator achieves low insertion loss and low polarization dependent loss of a device at the same time, and achieves power even distribution of two polarization states, the situation of modulation waveform distortion is effectively eliminated, and accuracy of electro-optical modulation is improved.

The invention provides a consistency droop control method for power distribution and voltage frequency recovery, which is used for an island micro-grid system, realizes accurate active and reactive power sharing, and simultaneously keeps frequency recovery and the average voltage at the rated value. In the proposed control scheme, only the neighborhood reactive power information needs to be exchanged by using a sparse low bandwidth communication network, instead of transferring the information of active power, reactive power and frequency through the communication link in the existing consistency method. Compared with the consistency-based method in the prior art, the transmission data and the data delay are significantly reduced, and the high reliability of the system can be realized. Furthermore, even in the case of the communication delay, accurate active/reactive power sharing and voltage frequency recovery can be ensured under the interference of load and feeder impedances. And finally, a simulation result of the hardware in the ring is given, and the effectiveness of the control scheme is verified.

A control method of a quasi-virtual synchronous machine comprises the steps of connecting a proportional controller in parallel with an inertial link of a virtual synchronous machine to form an activepower loop PI regulator and a reactive power loop PI regulator, converting characteristic of an original integral regulator to characteristic of the PI regulator, generating angle information of thevirtual synchronous machine by an active power controller taking the active power loop PI regulator as a core, generating voltage amplitude information of the virtual synchronous machine by a reactivepower controller taking the reactive power loop PI regulator as a core, and modulating to drive a three-phase bridge-arm insulated gate bipolar transistor (IGBT) to act after Park reverse conversionon the angle information and the amplitude information. Indifference control of an active power and a reactive power can be achieved during grid-connected running and when the voltage amplitude and the frequency of a power grid are normal, inertia and a primary regulation function can be provided when the power grid amplitude and the frequency are abnormal, and power equalization can be easily achieved during off-grid running.

The invention discloses a direct-current microgrid droop control method and relates to droop control methods, for solving the problem existing in conventional droop control that micro-source output voltage is decreased linearly along with increase of output current, direct-current bus generates high voltage deviation, and power distribution precision is low. The direct-current microgrid droop control method includes the steps of 1, introducing information of all micro-source output current and important bus voltage through low-speed communication; 2, implementing a linkage mechanism of current limit and current signal sending pause, to be specific, detecting power sent by every micro-source, sending an instruction to cut off a communication output channel switch once detecting that some of the micro-sources is loaded fully to prevent the micro-source from sending its current signal outwards but to allow the same to receive current signal sent from the other micro-sources and continue to generate power compensation and voltage compensation; and sending an instruction to close the communication output channel switch once detecting that the micro-source is not in full load. The direct-current microgrid droop control method improves quality of system voltage and guarantees normal running of the microgrid system even when the micro-sources select unreasonable droop coefficient.

The invention relates to the technical field of aircraft power supply systems, and discloses an aircraft multi-closed loop power supply adjustment system. The system comprises multiple parallel inverter unit systems connected to a high-voltage DC power supply system and an aircraft load control system respectively. The invention also discloses an aircraft multi-closed loop power supply adjustmentmethod. The voltage inputted to a linear load system and/or a nonlinear load system is adjusted to 115 V through the multiple parallel inverter unit systems and the connected double-closed loop controller; when the linear load system is accessed, load voltage adjustment is realized through a voltage outer loop controller in the double-closed loop controller; current adjustment of the connected inverter unit system is realized through a current inner loop controller in the double-closed loop controller; through a second-order power equalization and sharing algorithm, effective sharing of the power after the linear load system is accessed can be ensured; and when the nonlinear load system is accessed, through harmonic voltage loop compensation, harmonic suppression of each frequency is realized.

The invention provides an SOC balancing and power sharing control method of a direct-current micro-grid energy storage system. The method comprises the following steps: 1, acquiring state-of-charge values of a first battery and a second battery in real time through low-bandwidth communication; 2, calculating the average value of the charge state values of the first battery and the second battery; and 3, obtaining a difference value between the charge state value of the first battery or the charge state value of the second battery and the average value, inputting the difference value into a first PI controller, and outputting a regulating variable by the first PI controller. According to the method, bus voltage drop caused by a droop coefficient is effectively avoided, low-bandwidth communication is adopted, the average value of the SOC of different energy storage units is calculated, the SOC average value PI closed-loop control is adopted, the regulating variable acts on the output voltage reference value of the converter, SOC balance of the energy storage units is achieved, and power equalization is achieved under the condition that the capacities of the energy storage units are the same.

The invention discloses a delayed immunity power equally-dividing method based on band-pass filter (BPF). According to the method, by establishing an equivalent secondary control model without a communication line and further deducing a micro-grid small-signal model based on the BPF, a self-adaption high-pass filter coefficient and an optimal droop coefficient are obtained, and therefore the voltage amplitude and frequency dynamic stability of all distributed type generations (DG) are enhanced. The voltage amplitude and the frequency stability are kept at rationed values, and precise equal division of active powder under unbalanced resistance-inductance circuits is achieved. The method has the advantages that on the basis of a traditional droop control scheme, the voltage amplitude and frequency drop problem and the communication delayed problem caused by droop control are rapidly and accurately eliminated without introducing a wideband communication line or an additional control ring, the dynamic stability of the voltage amplitude and frequency is enhanced, the precise equal division of active power is achieved, and efficient and stable running of a micro-grid is ensured.

The invention discloses a grid-connected and isolated island control method of a single-phase parallel inverter. The grid-connected and isolated island control method comprises three parts including application of an inverter, grid-connected operation control and isolated island operation control. The grid-connected and isolated island control method adopts current closed-loop control during grid-connected operation, and realizes zero steady-state error adjustment by means of a quasi-PR regulator; the grid-connected and isolated island control method adopts droop control and combines virtual inductance to eliminate influence of inconsistent parameters of line impedance in an isolated island operation mode, and realizes the purposes of power sharing and circulating current restraining. Compared with the traditional extraction method, the grid-connected and isolated island control method adopting hybrid filter average power extraction can effectively suppress power oscillation and improve the electric energy quality of the system.

The invention provides a multi-machine parallel autonomous control device and a multi-machine parallel autonomous control method for a battery energy storage system. The multi-machine parallel autonomous control device comprises a converter main circuit connected with a multi-machine parallel energy storage system, and an upper computer and a digital signal processor which are mutually connected with the converter main circuit; and the upper computer is connected with the digital signal processor through the RS232, and is configured to issue a control instruction to the multi-machine parallelenergy storage system according to the received micro-grid voltage and output power sent by the multi-machine parallel energy storage system under frequency modulation control. The micro-grid voltagesof the multi-machine parallel energy storage system in twice frequency modulation control are detected in real time, and when the voltage of the micro-grid exceeds the limit, the excitation voltage control is executed to allow each battery energy storage system to rapidly connect into the micro-grid so as to meet the requirement of plug and play. When the power output between the multi-machine parallel energy storage systems has difference, virtual impedance is added to achieve power sharing.

The invention relates to a multi-power-taking-device automatic equalization control circuit of a non-contact power supply device and a control method. The circuit comprises a controller and a plurality of power taking devices, and the controller comprises a current sharing control circuit, an output voltage feedback differential circuit, a digital signal processor and a voltage given circuit. According to the multi-power-taking-device automatic equalization control method of the non-contact power supply device, the duty ratio of a BOOST circuit can be adjusted by means of the multi-power-taking-device automatic equalization control circuit of the non-contact power supply device, load currents of all power taking devices connected in parallel can be ensured to be the same, power is ensured to be equally divided, redundancy and reliability of the whole system are improved, the power expansion is realized, and the requirement of a high-power load can be met by using a plurality of standard power taking devices.

Disclosed is a large-capacity isolated DC/DC converter based on a multi-phase three-level inverter. If the converter is configured to comprise 2m input phases, m bridge arms and n gain units, the converter consists of a DC input voltage source, m bridge arms, 2m high-frequency transformers T1, T2, T3...T2m having a transformation ratio of 1: k, n gain units, an output filter capacitor C0, an output diode D0 and a load RL, wherein each bridge arm comprises four power switches and two diodes, and a DC power supply is connected in parallel to the upper and lower sides of the bridge arms. Amongthe gain units, the gain unit 1 comprises (2m-1) capacitors and (2m-1) diodes, and the gain unit 2 to the gain unit n respectively comprise 2 m capacitors and 2 m diodes. Compared with the existing three-level isolated DC/DC converter, the number of the bridge arms can be adjusted freely, the current of each bridge arm is automatically equalized, the voltage stress and current stress of all switches and diodes are significantly reduced and adjustable, and the input and output gains are high and also adjustable, so the converter is suitable for large-capacity and electrically isolated input andoutput applications.

The invention discloses a multi-module parallel control method and system. The multi-module parallel control method comprises the steps that a power supply main module is enabled to be in parallel connection with multiple power supply slave modules by adopting a communication connection mode; the power supply main module carries out sampling on voltage and current parameters of the system and obtains the output power required by a load after calculation, the output power is equally distributed, then the average power should be output by each power supply slave module is broadcast and transmitted to each power supply slave module through a communication bus; and finally, each power supply slave module receives the given power transmitted by the power supply main module and outputs the corresponding power through the control thereof. There is only a power instruction transmitted by the main module to the slave modules in a communication line, and no other interactive information is required, so that the communication speed is high and not affected by the number of parallel modules, and the capacity can be expanded conveniently.

The invention provides an energy storage system and a black start method thereof. The energy storage system can comprise a plurality of energy storage modules, a plurality of direct current switches, at least two energy storage converters and a plurality of alternating current switches, wherein the plurality of energy storage modules are connected with the input ends of the at least two energy storage converters through the plurality of direct current switches, and the output ends of the at least two energy storage converters are connected in parallel to a parallel operation point through a plurality of alternating current switches; when each energy storage converter in the at least two energy storage converters detects a black-start starting instruction, the direct current switch and the alternating current switch corresponding to each energy storage converter are switched on so as to be connected to a parallel operation point in parallel; and each energy storage converter is also used for carrying out soft start at a voltage phase zero-crossing position of the parallel operation point, so that the output alternating voltage reaches the rated voltage to realize black start of the energy storage system. In the energy storage system and the black start method thereof, synchronous soft start can be carried out at the voltage phase zero-crossing position of the parallel operation point, and synchronous startup of all the energy storage converters is ensured, so that the black start time is shortened, the ring current is reduced, and the applicability is high.

An undisturbed switching-based multi-target running optimal control method of a microgrid comprises the steps of 1, allowing each running mode to have respective controller with regard to a multi-moderunning switching system; 2, seeking admissible control Alpha <*> (t), and allowing a performance index function (3) to take minimum value according to an optimal control theory; 3, considering a control target of an island running mode as simultaneous average power for suppressing circulation; and 4, considering a running target of the microgrid under a grid-connected running mode, and designinga corresponding mode controller and an undisturbed switching compensation controller during switching from the island running mode to the grid-connected running mode. With the undisturbed switching compensation controller designed by the invention, the stability of the system and smooth and continuous transient-state performance can be ensured.

The invention discloses a hybrid LLC resonant converter topological structure based on working mode switching in the technical field of isolated switching power supplies, which comprises a main circuit and a control circuit, wherein the main circuit comprises an input side inverter network, an LLC resonant network, high-frequency transformers T1 and T2, a secondary side rectifier filter network and a voltage division sampling circuit, and the control circuit comprises an output current and voltage sampling circuit, a digital controller and a driving circuit. According to the invention, the switching-on and switching-off of four switching tubes of the hybrid LLC resonant converter are changed by controlling a PWM modulation signal, so that the topological structure conversion of the full-bridge LLC resonant converter and the half-bridge LLC resonant converter can be realized, no extra switching device needs to be added, and through the switching of the working modes of the hybrid LLC resonant converter, the loss of the LLC resonant converter under the light load condition is reduced, the efficiency of the converter is improved, electric energy is output through the single transformer and the two switching tubes in the later period of the charging process, and the problem of low efficiency during light load is solved.