Control and Simulation of a Grid-Forming Inverter for Hybrid PV-Battery Plants in Power System Black Start

TL;DR

This paper presents a novel control and simulation approach for a grid-forming inverter-based PV-battery plant designed to enable faster and more reliable black start capabilities in power systems, replacing traditional hydro and diesel units.

Contribution

It introduces a new modeling and control scheme for inverter-based PV-battery systems to serve as black start units, verified through detailed time-domain simulations.

Findings

Voltage and frequency stability during black start

Successful multi-step network energization

Effective inverter control mimicking synchronous machines

Abstract

Power system restoration is an important part of system planning. Power utilities are required to maintain black start capable generators that can energize the transmission system and provide cranking power to non-blackstart capable generators. Traditionally, hydro and diesel units are used as black start capable generators. With the increased penetration of bulk size solar farms, inverter based generation can play an important role in faster and parallel black start thus ensuring system can be brought back into service without the conventional delays that can be expected with limited black start generators. Inverter-based photovoltaic (PV) power plants have advantages that are suitable for black start. This paper proposes the modeling, control, and simulation of a grid-forming inverter-based PV-battery power plant that can be used as a black start unit. The inverter control includes both primary and secondary control loops to imitate the control of a conventional synchronous machine. The proposed approach is verified using a test system modified from the IEEE 9-bus system in the time-domain electromagnetic transient simulation tool PSCAD. The simulation results shows voltage and frequency stability during a multi-step black-start and network energization process.