Modeling and Control Strategy for Multiterminal Flexible DC Distribution Network with Echelon Utilization Power Battery

Abstract

With the integration of distributed renewable energy to the distribution network and the development of multiterminal flexible DC transmission technology, multiterminal flexible DC distribution network has broad application prospects. At the same time, with the rapid development of new energy vehicles, the echelon utilization of power battery has become a research hotspot. By analyzing the characteristics of flexible DC distribution network and echelon utilization battery, the structure and control strategy of modular multilevel converter (MMC), DC solid-state transformer, photovoltaic power generation, wind power generation, and echelon utilization battery energy storage system are established, respectively, in this paper. To achieve a DC network connection of various types of power supply and load, this paper proposes a starting method of multiterminal flexible DC distribution network and a cooperative control strategy of the wind-solar-storage system. A six-terminal ring-shape DC distribution network model is built in real-time digital simulation (RTDS) platform. The simulation results show that the modeling methods and control strategies of each component in the real-time simulation model meet the operation requirements of the multiterminal flexible DC distribution network, which provides a reference for the construction and research of the flexible DC distribution network.

Power quality control method of flexible AC transmission project based on harmonic suppression

“…For the system side, even if the corresponding 6kth ripple current generated by the 6kth characteristic harmonic voltage on the AC side is considered, the AC current and the 6kth ripple current are modulated by the switching function at the same time [4] . If the system voltage does not satisfy the ideal conditions and a non-characteristic harmonic voltage appears on the AC side, the corresponding noncharacteristic harmonic current will appear on the AC side after modulation by the switching function [5]. The multi-objective voltage reactive power harmonic optimization algorithm can optimize the grid system in many aspects, and the indicators of voltage qualification, reactive power compliance, network loss, voltage fluctuation and harmonic distortion are the target requirements of the optimization algorithm.…”

Multi-Objective Location Method for Small Capacity Distributed Generation under Timing Characteristics

“…Therefore, this paper establishes a multi-objective model of distribution network positioning and capacity determination based on DG and determines the target weight [8] of each subfunction. In this paper, on the premise of minimizing the grid loss, voltage deviation and comprehensive cost in the distribution network [9] gives different weights to the three IOP Publishing doi:10.1088/1742-6596/2565/1/012030 2 objectives and sets the objective function of power supply position and capacity, as shown in Formula (1). min ( , ) ( , ) 0 ( , ) 0…”

Passive control technology of flexible DC transmission converter based on improved Ant Lion algorithm

“…[1] proposes to use PI control to control the flow of energy inside the transmission converter, and improve the impedance characteristics of the substation system by combining the integral coefficient. [2] mainly solves the damping parameters by using sliding mode control, and takes them as the target control parameters to achieve the internal control of the transmission converter. [3] improves the dynamic tracking control performance of the controller by introducing damping parameters into conventional passive controllers.…”