Coordinated control of MMC‐HVDC system with offshore wind farm for providing emulated inertia support

Abstract

With the continuous increase of renewable energy generation and high voltage direct current (HVDC) power transmission, the system inertia is declining, thus resulting in greater risks of frequency instability. To solve this issue, a dc-link inertia control is firstly proposed for a point-to-point modular multilevel converter based HVDC (MMC-HVDC) link, which enables the MMC-HVDC system to provide emulated inertia support by employing the electrostatic energy stored in the dc capacitors. Moreover, in order to maintain reasonable submodule capacitor size as well as provide more emulated inertia support, a virtual capacitor control for MMC-HVDC connected an offshore wind farm (OWF) is proposed. With the virtual capacitor control, the OWF is able to provide a large capacity virtual capacitor in dc side of MMC-HVDC link and supply desired emulated inertia support for onshore power system by utilising the offshore wind turbines' rotor rotational kinetic energy. Furthermore, a procedure for selecting the appropriate virtual capacitor control parameters is proposed. Finally, the performance of the proposed coordinated control is researched in PSCAD/EMTDC, and the simulation results show that the onshore power system inertia is effectively improved with the coordinated control.

Frequency coordinated control strategy of HVDC sending system with wind power based on situation awareness

“…Formula (12) indicates that the rotating reserve capacity of the sending system is sufficient and the security margin of cooperative frequency regulation is good. Formula (16) indicates that the primary frequency regulation capability of the system is equivalent to that of the traditional power system. Formula (14) reflects the transient characteristics of the frequency response process and should satisfy the relevant provisions, and Δf max of the general large-scale system is no more than 0.2 Hz.…”

“…To coordinate the participation of wind power and HVDC in the system frequency regulation. In [16], the ability of fast frequency regulation is improved by adopting the virtual inertial control of wind power and DC power transmission. However, the excessive virtual inertia effect slows down the recovery process of frequency regulation.…”

Guest Editorial: Challenges in Future Grid‐Interactive Power Converters: ControlStrategies, Optimal Operation, and Corrective Actions

“…As a particular emphasis of this SI on VSM and inertia emulation, paper [1] proposes a dc-link inertia control for HVDC converter to provide emulated inertia support by using its DC capacitors. Similarly, paper [2] presents a VSM of a PV inverter based on the DC capacitor voltage control which can damp the built-up oscillations in response to the disturbances using a proposed feedforward grid angle.…”

DC voltage control for MMC‐based railway power supply integrated with renewable generation

“…Moreover, the SFC station enables effective feeding of regenerative power back to the grid. The modular multilevel converter topology has been intensively researched in recent years and has shown its advantages in high voltage direct current (HVDC) transmission system and high power conversion applications [14,9,25,20].…”