A Design Solution to Reduce DC Bus Voltage Stress in Single Switch Power Quality Converter

DG Grid interfaced system has been focused through this paper. The objective is to improve power quality of the grid, which was polluted by various means. The improvement of power quality of the micro grid includes uses of a specially designed DG, BESS and Power Quality conditioner. The system consists of a two-stage power conversion. Solar PV supplies power for both DC and AC loads. Manufacturer datasheet is used for modeling the PV panel. In order to keep the BUS voltage stable a BESS is joined to DC BUS through power electronic converter, which is used to absorb the excess power whenever production is high and deliver power to the load on low production. The system continues to supply the local loads, incase of grid discontinuity. Thus it eliminates threats of islanding. This paper also focuses on control and stability of DC bus voltage and energy management scheme. The project uses Matlab/Simulink platform for efficient verification. For power quality improvement of Micro Grid it uses 3leg inverter, which is coupled with SPV and MPPT with Battery storage, which is used as compensator for the whole system. For prevention to reduce voltage current and power flow between DG and Grid, it is necessary to have an optimum control. Through the adjustment of power circulation between shunt paired DG ensures current voltage and power on micro grid. +ve, -ve and Zero sequence components of currents and voltage can be adjusted by the suggested methodology in Grid tied DG system. The said PQC have multiple uses. Firstly as a power converter and secondly as a shunt APF for harmonic compensation on voltage, current and power (both active and reactive) for both balanced and unbalanced loads in the Grid tied DG system. It also cares for the neutral conductor. Either individually or in grid connected mode all the above objectives can be achieved. For the entire Grid, it is realized that after compensation three phase four wired un-balance loads looks as balanced linear resistive load for the Grid. All these task significantly replicated on MATLAB/Simulink. After compensation the total harmonic distortion on input voltage and current reduced drastically. IEEE519 in the range of 5% suitably accepts it.

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Three‐phase four‐wire unified power quality conditioner structure with independent grid current control and reduced dc‐bus voltage operating with inverted/dual compensating strategy

International Transactions on Electrical Energy Systems ◽

10.1002/2050-7038.12380 ◽

2020 ◽

Vol 30 (6) ◽

Author(s):

Rodrigo A. Modesto ◽

Sérgio A. O. Silva ◽

Azauri A. Oliveira

Keyword(s):

Power Quality ◽

Current Control ◽

Grid Current ◽

Unified Power Quality Conditioner ◽

Three Phase ◽

Dc Bus ◽

Bus Voltage ◽

Power Quality Conditioner

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Control Strategy of Intergrated Photovoltaic-UPQC System for DC-Bus Voltage Stability and Voltage Sags Compensation

Energies ◽

10.3390/en12204009 ◽

2019 ◽

Vol 12 (20) ◽

pp. 4009

Author(s):

Dongsheng Yang ◽

Zhanchao Ma ◽

Xiaoting Gao ◽

Zhuang Ma ◽

Enchang Cui

Keyword(s):

Power Quality ◽

Control Strategy ◽

Control Method ◽

Integrated System ◽

Normal Operation ◽

Photovoltaic Array ◽

Point Tracking ◽

Dc Bus ◽

Bus Voltage ◽

Power Point

Power quality problem, because of its various forms and occurrence frequency, has become one of the most critical challenges confronted by a power system. Meanwhile, the development of renewable energy has led to more demands for an integrated system that combines both merits of sustainable energy generation and power quality improvement. In this context, this paper discusses an integrated photovoltaic-unified power quality conditioner (PV-UPQC) and its control strategy. The system is composed of a series compensator, shunt compensator, dc-bus, and photovoltaic array, which conducts an integration of photovoltaic generation and power quality mitigation. The fuzzy adaptive PI controller and the improved Maximum Power Point Tracking (MPPT) technique are proposed to enhance the stability of dc-bus voltage, which is aimed at the power balance and steady operation of the whole system. Additionally, the coordinate control strategy is studied in order to ensure the normal operation and compensation performance of the system under severe voltage sag condition. In comparison to the existing PV-UPQC system, the proposed control method could improve the performance of dc-bus stability and the compensation ability. The dynamic behavior of the integrated system were verified by simulation in MATLAB and PLECS. Selected results are reported to show that the dc-bus voltage was stable and increased under severe situations, which validates the effectiveness of the proposed integrated PV-UPQC system and its control strategy.

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