Slide mode control of microgrid using small hydro driven single‐phase SEIG integrated with solar PV array

Abstract

This study presents a susceptance theory-based sliding mode control (STSMC) algorithm for an improved power quality voltage and frequency control of a single-phase microgrid. The proposed microgrid includes a governor-free small hydro turbine-driven single-phase two winding self-excited induction generator (SEIG), a solar PV array and a battery energy storage system (BESS). The non-linear relationship among magnetising reactance, frequency and speed of SEIG along with random fluctuation in active power output of the solar PV array create the major challenge in frequency and voltage control of such renewable energy-based microgrid. The STSMC algorithm is found suitable to control frequency and voltage of such non-linear and complex system. In this proposed control, the system frequency control in dynamics and steady-state conditions and balance of power among various energy sources and BESS are achieved using the sliding mode control. The STSMC eliminates all possibilities of overshoot and undershoot problem in DC-link voltage of the VSC, which in turn reduces the required size of DC-link capacitor and BESS.

A Comprehensive Overview of Single–Phase Self-Excited Induction Generators

“…Single-phase induction generators can also be integrated in single-phase microgrids (MG). Such a MG has the load connected across the main winding of a SPIG; an inverterbattery system connected in parallel with the load transfers the power from the other two sources: a permanent magnet synchronous generator (PMSG) -based small wind turbine and a PV panel, both interfaced through power converters with the inverter DC link [71,72].…”

“…Another control algorithm, named adaptive sliding mode control, was developed by the authors of [71,72] to ensure, besides voltage and frequency regulation, the SPIG-based MG power quality. It involved two control loops for active and reactive power balancing in case of both sudden load variations and primary resources power modification.…”

“…When complex MG structures are investigated, the focus shifts from investigating the SPIG characteristics/behavior towards ensuring the MG control for autonomous operation with the help of power converters [71,72].…”

Dynamic characteristics of a hydro‐turbine governing system considering draft tube pressure pulsation

“…There is a certain degree of pressure pulsation which cannot be avoided in the draft tube during the operation of a hydropower station [1][2][3]. It can cause turbine output fluctuation, penstock hammer, unit vibration and so on, which brings challenges for the hydro-turbine governing system (HTGS) to regulate the transient characteristics of the hydropower system [4][5][6][7]. In general, draft tube pressure pulsations are often caused by vortex rope in a draft tube under part-load condition.…”

A Constant Grid Interface Current Controller for DC Microgrid

“…For example, it has been reported that PV generation injecting an exceedingly distorted current into the grid [5]. The impacts of the increasing PV generation on the grid has been investigated, and based on the findings of various studies, several control techniques have been developed to reduce the disturbance to the grid, which include sliding mode control [6], Droop control [7], and feedback linearizing control [8]. In each case, these control techniques are integrated with the battery charging/discharging controllers to absorb the PV fluctuation.…”