Optimal control of a single‐phase H‐bridge DC–AC inverter

Summary This paper presents a unified and exact nonaveraged approach to derive a frequency‐domain control‐oriented model for accurate prediction of the fast timescale dynamics and performances of switching converters with fixed frequency naturally sampled pulse width modulation and integrating feedback loop. Because the approach avoids averaging and approximations related to this process, a very good accuracy of the derived model is obtained. The main difference between the presented approach and the existing methodology for accurately predicting the behavior of switching converters is that, here, we break the feedback loop and we focus on analyzing the open‐loop gain and the effect of the system parameters on relative stability. This results in an approach much similar to control systems techniques rather than nonlinear dynamical system approaches. Consequently, the relative stability is tackled easily in the frequency domain. In particular, by treating the modulator as a gain depending on the operating point, the new model is formulated in such a way that standard control‐oriented tools such as Bode diagrams and root‐loci can be easily used. Therefore, the proposed approach gives some important issues like gain and phase margins that are highly useful in controller design. It is noticed that the crossover frequency, gain, and phase margins predicted by using the averaged model may deviate significantly from the actual values given by the proposed approach. The paper points out the sources of discrepancies and the theoretical results are validated by simulations using a circuit‐level switched model.

mentioning

confidence: 99%

Nonaveraged control‐oriented modeling and relative stability analysis of DC‐DC switching converters

Al‐Turki

Aroudi

Mandal

et al. 2017

“…E is the external DC input. Optimal control of DC/AC inverters with an H-bridge topology has been obtained in Miladi et al 13 Here, we aim to stabilize the output of the inverter with PBC.…”

Section: Buck-type Invertermentioning

confidence: 99%

“…Power inverters play the role of an interface to transfer energy from DC sources of electricity to AC voltage form with a desired frequency. 12,13 The buck-type inverter circuit employs the circuit configuration of a DC/DC buck converter with the DC input switched using an H-bridge circuit which enables to change the polarity to obtain AC output voltage.…”

Section: Introductionmentioning

confidence: 99%

Phase synchronization of autonomous AC grid system with passivity‐based control

Manohar

Hikihara

2020

This paper discusses a ring-coupled buck-type inverter system to harness energy from direct current (DC) sources of electricity. The DC-DC buck converter circuit is modified with an H-bridge to convert the DC input voltage to a usable alternating current (AC) output voltage. Passivity-based control (PBC) with port-controlled Hamiltonian modelling (PCHM) is a method where the system is controlled by considering not only the energy properties of the system but also the inherent physical structure. PBC is applied to achieve stabilization of the AC output voltage to a desired amplitude and frequency. Unsynchronized output voltages in terms of phase angle or frequency can cause detrimental effects on the system. Phase-locked loop (PLL) is employed in the ring structure to maintain synchronization of the AC output voltage of all inverter units in the ring-coupled system. KEYWORDSbuck-type inverter, distributed generation, passivity-based control, ring-coupled system, synchronization 906

“…Hopf bifurcation was witnessed in a double‐input buck/buck‐boost inverter with resistive load 26 and digital‐controlled grid connected inverter 27 . A plethora of work on chaos control of inverter considers linear resistive load, 28 mostly in conjunction with an inductor 29–32 . Rigorous analysis of 1‐D map of a generalized switching circuit with multiple inputs revealed coexisting attractors, nonsmooth PD, and pitchfork bifurcations 33 …”

Section: Introductionmentioning

confidence: 99%

“…27 A plethora of work on chaos control of inverter considers linear resistive load, 28 mostly in conjunction with an inductor. [29][30][31][32] Rigorous analysis of 1-D map of a generalized switching circuit with multiple inputs revealed coexisting attractors, nonsmooth PD, and pitchfork bifurcations. 33 Based on simulation results only, earlier onset of both Hopf and PD bifurcations in two parallel connected inverters with rectifier load when compared to resistive load were reported.…”

mentioning

confidence: 99%

A Filippov method based analytical perspective on stability analysis of a DC‐AC H‐bridge inverter with nonlinear rectifier load

Bandyopadhyay

Mandal

Parui

2022

Summary A comprehensive analysis of an inverter with nonlinear rectifier load by Filippov's method and state‐space averaged method considering nonidealities have been reported for the first time. A study in comparison with an equivalent linear AC resistance load reveals that even though qualitative behavior remains similar, earlier onset of Hopf bifurcation and delayed onset of period‐doubling bifurcation occur. This proves the necessity of modeling the nonlinear load at a switched system level, instead of linearizing it based on the first harmonic approximation which ignores the capacitor after rectifier and reduces the order of the system from four to three. Hopf bifurcation takes place with increase in capacitance after rectifier, along with corresponding decrease in its equivalent series resistance (ESR), limiting the selection of capacitors to lower values. However, ESR compensation solves this problem by preventing the onset of Hopf bifurcation and use of ESR compensated capacitor of higher values result in significant increase, instead of reduction in overall stable domain in parameter spaces. Analytical results have been corroborated by numerical simulation results.