Contribution to the design of the closed-loop control of a real-time power simulator

Abstract

The energy transition has spurred Hydro-Québec’s research institute (IREQ) to acquire a 7.5-MVA power simulator that will allow for the connection of power equipment to various power systems simulated in real time on Hypersim. This kind of “power-hardware-in-the-loop” (PHIL) system is an emerging power grid technology whose implementation is still very challenging. The main challenge revolves around the control of the signals exchanged by the simulator and the amplifier at their point of interface. More specifically, delays that occur at the interface may compromise the operating stability or dynamic performance of the system. First, a new basis has been established to understand the stability of PHIL systems in light of their hybrid (digital-analog) nature. The conventional method for determining stability criteria is not appropriate as it assumes a continuous model of PHIL systems. A new stability analysis method based on the discrete impedance frequency response is thus presented. Second, this dissertation presents a stable, robust and accurate interface for PHIL simulator based on the Bergeron transmission line model (BTLM). Two limitations of this interface are identified, and corrective strategies are formulated to ensure its compatibility with the PHIL application. Stability, passivity and accuracy analyses are then performed to verify its performance. The proposed interface has been implemented in a 3-kVA experimental PHIL test bench designed and built at IREQ. Several tests have been performed to demonstrate the stability and accuracy of the closed-loop system for various pieces of equipment under a wide range of operating conditions. Third, the PHIL test bench was used to identify the characteristics of residential photovoltaic inverters connected to a typical distribution system. An aggregation method was developed to develop realistic testing parameters. Close-loop testing revealed operating anomalies that occur when such inverters are connected to certain types of power systems.

Date	15 Dec 2020
Original language	American English
Awarding Institution	École de technologie supérieure
Supervisor	Handy Fortin Blanchette (Supervisor) & Richard Gagnon (Co-supervisor)