• Journal of IKEEE
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• v.24 no.3
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• pp.877-882
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• 2020

This paper presents performance comparison study of current control methods for grid connected inverter (GCI) system. Different current control methods have been developed for GCI systems and each controller has its own advantages and limitations. Steady state and transient dynamic performance of the GCI current controllers are compared in this paper. The performance of the proposed command feedforward control (CFFC) and disturbance rejection control (DRC) is analyzed before and after application to all GCI current controllers. The proposed CFFC and DRC control algorithms is analyzed in a frequency domain and the simulation and experiment models of each GCI current control methods are developed for verification of the performance.

• The Transactions of the Korean Institute of Power Electronics
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• v.17 no.1
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• pp.1-7
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• 2012

This paper describes the performance comparison results for current controller of a single-phase PFC converter with 1-switch voltage doubler strategy for single-phase double-conversion UPS(Uninterruptible Power Supply). A single-phase PFC converter with 1-switch voltage doubler strategy needs a diode bridge and one bidirectional active switch. Thus it is possible to reduce the material cost. However, the study results of current controller design and comparison of current control method has not been known after the converter circuit was proposed. For the performance comparison of current control, single-phase 3 kVA double-conversion UPS was tested. The performance of PI and PR current controller is experimentally confirmed with followings - input current reference tracking, input power factor correction and input current THD suppression.

• Journal of Power Electronics
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• v.17 no.2
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• pp.464-475
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• 2017

This study examines a P+multi resonant-based voltage control for voltage harmonics compensation under the islanded mode of a microgrid. In islanded mode, the inverter is defined as a voltage source to supply the full local load demand without the connection to the grid. On the other hand, the output voltage waveform is distorted by the negative and zero sequence components and current harmonics due to the unbalanced and nonlinear loads. In this paper, the P+multi resonant controller is used to compensate for the voltage harmonics. The gain tuning method is assessed by the tendency analysis of the controller as the variation of gain. In addition, this study analyzes the slight voltage magnitude drop due to the practical form of the P+multi resonant and proposes a counter method to solve this problem by adding the PI-based voltage restoration method. The proposed P+multi resonant controller to compensate for the voltage harmonics is verified through the PSIM simulation and experimental results.

• Journal of Power Electronics
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• v.11 no.2
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• pp.120-131
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• 2011

This paper proposes two control strategies for the bidirectional Z-source inverters (BZSI) supplied by batteries for electric vehicle applications. The first control strategy utilizes the indirect field-oriented control (IFOC) method to control the induction motor speed. The proposed speed control strategy is able to control the motor speed from zero to the rated speed with the rated load torque in both motoring and regenerative braking modes. The IFOC is based on PWM voltage modulation with voltage decoupling compensation to insert the shoot-through state into the switching signals using the simple boost shoot-through control method. The parameters of the four PI controllers in the IFOC technique are designed based on the required dynamic specifications. The second control strategy uses a proportional plus resonance (PR) controller in the synchronous reference frame to control the AC current for connecting the BZSI to the grid during the battery charging/discharging mode. In both control strategies, a dual loop controller is proposed to control the capacitor voltage of the BZSI. This controller is designed based on a small signal model of the BZSI using a bode diagram. MATLAB simulations and experimental results verify the validity of the proposed control strategies during motoring, regenerative braking and grid connection operations.