Analysis of an H∞ Robust Control for a Three-Phase Voltage Source Inverter

Abstract

Recently, power quality improvement has gained a lot of attention due to the rapidly increasing use of power electronics equipment. Several control strategies for DC/AC Voltage Source Inverters (VSI) have been developed to obtain good quality output with low harmonic distortion. This paper proposes a robust control scheme to improve the power quality of a three-phase DC/AC VSI. The control scheme includes an outer voltage loop and an inner current loop, with both controllers designed by the standard H∞ robust control technique. The system with the proposed controller has a low total harmonic distortion (THD) and improved power quality of output voltage in the presence of linear and non-linear loads. The simulation is carried out in MATLAB/Simulink environment, and the results of the proposed control scheme are compared with the performance of dead-beat (DB) predictive control and conventional proportional integral (PI) control. It is observed from the results that the proposed control scheme outperforms other control schemes in terms of the THD level, having a better steady-state and transient performance.

Utilizing Full Degrees of Freedom of Control in Voltage Source Inverters to Support Micro-Grid with Symmetric and Asymmetric Voltage Requirements

“…g , then the dynamics of errors for these powers' ( ėPg , ėQg ) exchange can be given as below [24]:…”

“…The random nature of the loads in the distribution system connected to the MG introduces a demand for imbalance voltage generation or imbalance current compensation from the VSI. This asymmetric voltage generation demand from the VSI requires it to employ the full capabilities (DOF) of its switching matrix [24]. All three-phase converters have three independent control inputs but, in general, in all techniques, the desired outputs are defined either as control of current (orthogonal dq-/αβ-frames) or control of power (active and reactive, power frames), resulting in 2D control requirements.…”

Comparative Performance Analysis of the DC-AC Converter Control System Based on Linear Robust or Nonlinear PCH Controllers and Reinforcement Learning Agent

“…Based on these specifications, Equation (6) will be extended in the form of Equations (7) and (8) [ 13 , 16 , 17 ]. …”

“…Using the notations in Section 2.1 , the extended plant P takes the following form [ 13 , 16 , 17 ]: …”

“…Traditionally, PI-type controllers are used, which offer relatively good performance and parametric robustness, but only around static operating points established after the tuning of the PI-type controller [ 11 ]. Naturally, to obtain superior control performances, a series of modern types of controllers have been developed and implemented specifically for the control of the main elements of the microgrid described above, including adaptive controllers [ 12 ], robust controllers [ 13 , 14 , 15 , 16 , 17 ] in case of significant parametric variations, neuro-fuzzy controllers [ 18 ], as well as nonlinear controllers based on the Passivity theory, including nonlinear PCH [ 19 , 20 , 21 , 22 , 23 ].…”