Decentralized Voltage Control Method for Microgrid Based on Nonlinear State Observers

    公开(公告)号:US20180358840A1

    公开(公告)日:2018-12-13

    申请号:US16107932

    申请日:2018-08-21

    Abstract: A decentralized voltage control method for a microgrid based on nonlinear state observers, comprising the steps of step 10), establishing a large-signal model of distributed generations, a connection network and impedance-type loads in the microgrid; step 20), establishing a Luenberger-like nonlinear state observer for each distributed generation; step 30), estimating the dynamic characteristics of other distributed generations in real time based on the local measured values of each distributed generation; and step 40), implementing the decentralized voltage control based on the control requirements of reactive power sharing and voltage restoration. The control method realizes the voltage control of microgrid based on the decentralized state observers, which does not rely on communication transmission or remote measurement and avoids the adverse effects of communication latency and data drop-out on the control performance.

    METHOD FOR DESIGNING DISTRIBUTED COMMUNICATION TOPOLOGY OF MICRO-GRID BASED ON NETWORK MIRRORING AND GLOBAL PROPAGATION RATES

    公开(公告)号:US20220094603A1

    公开(公告)日:2022-03-24

    申请号:US17283257

    申请日:2020-04-02

    Abstract: A method for designing a distributed communication topology of a micro-grid based on network mirroring and global propagation rates includes the following steps: first, determining the communication connectivity of distributed directed networks in the micro-grid; next, obtaining, for connected directed communication networks, mirror networks thereof based on a mirroring operation, and selecting an optimal distributed directed communication topology corresponding to a maximum performance indicator based on algebraic connectivity and communication costs; solving, for the optimized distributed communication topology, pinned distributed generation sets corresponding to different pinning numbers based on global propagation rates and out-degrees; and finally, establishing a distributed secondary voltage control of the micro-grid based on the optimal distributed communication network and pinned nodes of the micro-grid, to achieve accurate reactive power sharing and average voltage restoration.

    MICROGRID DELAY MARGIN CALCULATION METHOD BASED ON CRITICAL CHARACTERISTIC ROOT TRACKING

    公开(公告)号:US20200293703A1

    公开(公告)日:2020-09-17

    申请号:US16618378

    申请日:2018-04-27

    Abstract: A microgrid delay margin calculation method based on critical characteristic root tracking includes: establishing a microgrid closed-loop small-signal model with voltage feedback control amount including communication delay based on a static output feedback, so as to obtain a characteristic equation with a transcendental term, performing critical characteristic root locus tracking for the transcendental term of the system characteristic equation, searching for a possible pure virtual characteristic root, and further calculating the maximum delay time in a stable microgrid. The method studies the relationship between the controller parameters and delay margins, thereby guiding the design of the control parameters, effectively improving the stability and dynamic performance of the microgrid.

    GENERAL DISTRIBUTED CONTROL METHOD FOR MULTI-MICROGRIDS WITH PQ CONTROL AND DROOP CONTROL

    公开(公告)号:US20190074691A1

    公开(公告)日:2019-03-07

    申请号:US15763733

    申请日:2016-12-16

    Abstract: The invention discloses a general distributed control method for multi-microgrids with both PQ controlled and droop controlled distributed generators, which comprises the following steps of: step 10) conducting primary control to maintain the power balance of the multi-microgrids; step 20) determining predefined group consensus values of pinned agents; step 30) seeking group consensus among other agents and the pinned agents through communication coupling; and step 40) adjusting output powers to complete secondary control. Based on pinning control, the control method which adopts hierarchical control is a distributed control method for distributed power supply clusters with two control modes comprising PQ control and droop control. The method obviates the requirements for a central controller and complex communication topologies, reduces the number of the controllers, can be adapted to the communication topology changes in the multi-microgrids, and meets the plug-and-play requirement for the distributed power supply.

    DISTRIBUTED PREDICTIVE CONTROL BASED VOLTAGE RESTORATION SCHEME FOR MICROGRIDS

    公开(公告)号:US20180138705A1

    公开(公告)日:2018-05-17

    申请号:US15552189

    申请日:2016-12-16

    Abstract: A distributed predictive control based voltage restoration scheme for microgrids, comprising: step 10) adopting a distributed finite time observer to acquire the global reference voltage for restoring the voltage of each local controller; step 20) each local controller adopts a droop control to acquire the local voltage value of each generation, and adds a secondary voltage compensation term into the droop characteristic formula to form the voltage reference value of a distributed generation; step 30) establishing a trended prediction model; step 40) acquiring a predictive control term at a current time as the secondary voltage compensation command, and acting on the local controllers; and step 50) determining, whether the local voltage of each distributed generation of the microgrid reaches the voltage reference value under the secondary voltage compensation command.

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