Optimal LQR-based multi-loop linear control strategy for UPS inverter applications using resonant controller

Hasanzadeh, A.; Edrington, Chris S.; Maghsoudlou, B.; Mokhtari, Hossein

doi:10.1109/cdc.2011.6161192

Cited by 12 publications

(8 citation statements)

References 14 publications

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“…In VSI, to avoid steady-state error, slow transient response, and reject disturbances, based on IMP the well known proportional-resonant (PR) controller (4) is applied within the output voltage loop [4][5][6].…”

Section: Full-state Merging Of Vsi Plant and Controllermentioning

confidence: 99%

“…The quality of voltage which includes the switching frequency content is related to cut-off frequency of the LC filter where price and volume may lead to clear restrictions on suitable filtering performance. To increase the filter damping capability of poorly damped pole pairs, an appropriate resistance can be added as passive damping [1] or a suitable controller structure may be used as active damping [2][3][4]. On the other hand, it is a well-known strategy to utilize resonant multi-loop control structure which uses filter current (inductor or capacitor) as the second feedback signal in addition to the load voltage [4][5][6].…”

Section: Introductionmentioning

confidence: 99%

“…To increase the filter damping capability of poorly damped pole pairs, an appropriate resistance can be added as passive damping [1] or a suitable controller structure may be used as active damping [2][3][4]. On the other hand, it is a well-known strategy to utilize resonant multi-loop control structure which uses filter current (inductor or capacitor) as the second feedback signal in addition to the load voltage [4][5][6]. Some methods also use load current feed-forward as well as time-derivatives of the reference signal to achieve better performance [7].…”

Section: Introductionmentioning

confidence: 99%

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Optimal linear controller design of standalone VSI including emulated output current state

Hasanzadeh

Edrington

Leonard

2012

IECON 2012 - 38th Annual Conference on IEEE Industrial Electronics Society

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Load type can introduce at least one additional state variable in the state-space representation f or dynamic equations of voltage source inverters (VSI) which may make controller design harder to solve. Additionally, the voltage reference term in state space realization demonstrates the VSI control as a tracking problem. This tracking problem can be transformed into a regulation problem using appropriate transformation; consequently, the linear quadratic regulator (LQR) technique, which is originally applicable to regulation problem, can be employed to design a linear controller including load current state for standalone VSls. The load current is also virtually obtained by an Enhanced Phase Lock Loop (EPLL) in the control structure instead using o f a current sensor in hardware. The controller is designed for a VSI unit and then simulation and experimental results are presented to confirm per f ormance o f the proposed controller.

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Section: Full-state Merging Of Vsi Plant and Controllermentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Optimal linear controller design of standalone VSI including emulated output current state

Hasanzadeh

Edrington

Leonard

2012

IECON 2012 - 38th Annual Conference on IEEE Industrial Electronics Society

Self Cite

View full text Add to dashboard Cite

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“…In [21], LQR technique is proposed for the current control of grid-connected inverter by considering its advantages, such as good transient response and excellent stability margins. Other applications of LQR for converter control are on three-phase power converters Space Vector Pulse Width Modulation (SVPWM) [22], multi-loop linear control strategy for UPS inverter [23], and a three-phase three-switch three-level AC/DC converter [24].…”

Section: Introductionmentioning

confidence: 99%

Interlink Converter with Linear Quadratic Regulator Based Current Control for Hybrid AC/DC Microgrid

2017

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A hybrid alternate current/direct current (AC/DC) microgrid consists of an AC subgrid and a DC subgrid, and the subgrids are connected through the interlink bidirectional AC/DC converter. In the stand-alone operation mode, it is desirable that the interlink bidirectional AC/DC converter manages proportional power sharing between the subgrids by transferring power from the under-loaded subgrid to the over-loaded one. In terms of system security, the interlink bidirectional AC/DC converter takes an important role, so proper control strategies need to be established. In addition, it is assumed that a battery energy storage system is installed in one subgrid, and the coordinated control of interlink bidirectional AC/DC converter and battery energy storage system converter is required so that the power sharing scheme between subgrids becomes more efficient. For the purpose of designing a tracking controller for the power sharing by interlink bidirectional AC/DC converter in a hybrid AC/DC microgrid, a droop control method generates a power reference for interlink bidirectional AC/DC converter based on the deviation of the system frequency and voltages first and then interlink bidirectional AC/DC converter needs to transfer the power reference to the over-loaded subgrid. For efficiency of this power transferring, a linear quadratic regulator with exponential weighting for the current regulation of interlink bidirectional AC/DC converter is designed in such a way that the resulting microgrid can operate robustly against various uncertainties and the power sharing is carried out quickly. Simulation results show that the proposed interlink bidirectional AC/DC converter control strategy provides robust and efficient power sharing scheme between the subgrids without deteriorating the secure system operation.

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“…For UPS voltage controls, repetitive-based control [1]- [4], deadbeat control [5], [6] and multi-loop state feedback control [7], have been proposed and investigated. Over these control methods, high quality output voltage and fast dynamic response have been demonstrated.…”

Section: Introductionmentioning

confidence: 99%

Load impedance estimation and iterative-learning control for a single-phase three-wire inverter

Kuo

Lin

et al. 2013

2013 IEEE Energy Conversion Congress and Exposition

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This paper presents a load impedance estimation and iterative-learning control for a single-phase three-wire inverter acting as an uninterruptible power supply (UPS), which can supply unbalanced load, linear load and rectified load. The proposed load impedance estimation scheme is based on an RLC equivalent circuit concept to determine load parameters, RLC, insuring that the inverter can generate sinusoidal voltage. With an iterative learning control, the steady-state error of the output voltage can be reduced significantly. Additionally, the proposed control can accommodate wide inductance variation of the inverter, reducing core size significantly. In the design and implementation, the inverter inductances corresponding to various inductor currents are measured at the start-up and stored in the memory of the controller for scheduling loop gain every switching cycle, and the RLC load parameters are estimated online to determine control (duty ratio). Experimental results measured from a 5 kVA inverter have verified the analysis and discussion.

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Optimal LQR-based multi-loop linear control strategy for UPS inverter applications using resonant controller

Cited by 12 publications

References 14 publications

Optimal linear controller design of standalone VSI including emulated output current state

Optimal linear controller design of standalone VSI including emulated output current state

Interlink Converter with Linear Quadratic Regulator Based Current Control for Hybrid AC/DC Microgrid

Load impedance estimation and iterative-learning control for a single-phase three-wire inverter

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