Research Roadmap on Grid-Forming Inverters

Abstract

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Grid-Forming Control for Solar PV Systems With Power Reserves

“…Such support by GFL converters may be not very effective during a disturbance for several reasons ( [1], [5]- [7]): i) sensing and actuation delays, ii) weak grids due to decreasing synchronous generation and remote IBR connection, and iii) challenges in the phase locked loop (PLL) and rate of change of frequency (RoCoF) measurement. These limitations impede high GFL-based RESs penetration to the grid [8], [9].…”

“…In contrast to GFL, the GFC converter acts as a controllable voltage source that can establish voltage and frequency in the network. The GFC source is robustly synchronized to the grid, and any disturbance is automatically catered instantly, not relying on a PLL that malfunctions in weak grids like in the GFL case [8]. Stabilitywise, GFC exhibits superior dynamic performance over GFL and synchronous machines (SMs) in terms of frequency stability [12]- [13] and short-term voltage stability [14].…”

“…Stabilitywise, GFC exhibits superior dynamic performance over GFL and synchronous machines (SMs) in terms of frequency stability [12]- [13] and short-term voltage stability [14]. In addition, GFC is necessary for islanded operation and black start services, functions that will be critical in a high-IBR future power system [8]. GFC is the only way for a power system with 100% IBRs and a promising method for high-RESs penetration [10]- [11].…”

“…There are a few variants of GFC implementation depending on how the reference voltage is generated [12], [16], such as droop control [12]- [17], virtual synchronous machine (VSM) control [13], [17][18], matching control [13], [17], [19], and virtual oscillator based control (VOC) [13], [20]. All these alternatives can be tuned for a similar steady-state response, but they differ during transient conditions as per their characteristics [13], [8]. Out of these, droop control is the most mature and widely used [8].…”

“…All these alternatives can be tuned for a similar steady-state response, but they differ during transient conditions as per their characteristics [13], [8]. Out of these, droop control is the most mature and widely used [8].…”