scholarly journals Control of a Four-wire Hybrid Prosumer Converter for Balancing Utility Grids

2021 ◽  
Vol 6 (1) ◽  
pp. 1-11
Author(s):  
Kwaśny Łukasz ◽  
Dariusz Zieliński
Keyword(s):  
Energy Storage ◽  
Reactive Power ◽  
Storage Device ◽  
Programming Environment ◽  
Power Electronic ◽  
Active And Reactive Power ◽  
Model And Simulation ◽  
Three Phase ◽  
Dc Line ◽  
Phase Converter

Abstract The paper presents the project of the power electronic AC/DC converter operating under a multiresonant control algorithm for prosumer applications. This design allows independent control of active and reactive power for any or each phase. Both the converter and its algorithm are based on a three-phase converter of four-wire topology (AC/DC 3p-4w) with a DC bus, which couple the converter to a renewable energy source and energy storage. Further, model and simulation tests were carried out in the Matlab-SIMULINK programming environment. The results obtained indicate that operation with deep unbalances and powers of opposite signs in individual phases results in current variations (oscillations) in the DC line, which is a significant limitation, and it can be concluded that the level of asymmetry should be limited to the level acceptable to the energy storage device.

scholarly journals Attenuation of DC-Link Pulsation of a Four-Wire Inverter during Phase Unbalanced Current Operation

2021 ◽  
Vol 11 (3) ◽  
pp. 1322
Author(s):  
Dariusz Zieliński ◽  
Karol Fatyga
Keyword(s):  
Energy Storage ◽  
Control Algorithm ◽  
Reactive Power ◽  
Lithium Ion ◽  
Power Converter ◽  
Dual Active Bridge ◽  
Three Phase ◽  
Ion Storage ◽  
Energy Store ◽  
Phase Converter

This paper proposes a control algorithm for a hybrid power electronic AC/DC converter for prosumer applications operating under deep phase current asymmetry. The proposed system allows independent control of active and reactive power for each phase of the power converter without current pulsation on the DC link connected to an energy store. The system and its algorithm are based on a three-phase converter in four-wire topology (AC/DC 3p-4w) with two dual-active bridge (DC/DC) converters, interfaced with a supercapacitor and an energy storage. The control algorithm tests were carried out in a Hardware in the Loop environment. Obtained results indicate that operation with deep unbalances and powers of opposite signs in individual phases leads to current oscillations in the DC link. This phenomenon significantly limits energy storage utilization due to safety and durability reasons. The proposed algorithm significantly reduces the level of pulsation in the DC link which increases safety and reduces strain on lithium-ion storage technology, enabling their application in four-wire converter applications.

Three-phase series-connected photovoltaic generator for harmonic and reactive power compensation with battery energy storage device

2016 ◽  
Vol 39 (7) ◽  
pp. 1071-1080
Author(s):  
Maheswar P Behera ◽  
Pravat K Ray
Keyword(s):  
Energy Storage ◽  
Reactive Power ◽  
Voltage Source ◽  
Storage Device ◽  
Voltage Source Converter ◽  
Radiation Level ◽  
Battery Energy Storage ◽  
Three Phase ◽  
Dc Bus ◽  
Battery Energy

This paper presents a photovoltaic (PV) generator along with a battery energy storage system connected in series with a three-phase grid. The objective of the proposed system is to provide uninterruptable compensation to the series-connected grid and non-linear load during strong sunlight as well as at night or in cloudy conditions. The interface between the grid and the PV is carried out through a voltage source converter (VSC), eliminating both the current and voltage harmonics and compensating the reactive power. The DC voltage control of the DC bus capacitor is employed in order to maintain unity power factor operation of the system, irrespective of changes in solar radiation level or due to change in load. Another control scheme is implemented to charge and discharge the connected battery whenever the sun goes out, to meet the DC bus voltage requirement of the VSC through a bidirectional DC-DC converter.

Wind-Solar-Hydrogen Hybrid Energy Control Strategy Considering Delayed Power of Hydrogen Production

2021 ◽  
Vol 69 (2) ◽  
pp. 5-12
Author(s):  
Zheng Li ◽  
Yan Qin ◽  
Xin Cao ◽  
Shaodong Hou ◽  
Hexu Sun
Keyword(s):  
Energy Storage ◽  
Control Strategy ◽  
Reactive Power ◽  
Storage System ◽  
Energy Storage System ◽  
Storage Device ◽  
Solar Hydrogen ◽  
Dc Voltage ◽  
Hybrid Energy ◽  
Load Demand

In order to meet the load demand of power system, BP based on genetic algorithm is applied to the typical daily load forecasting in summer. The demand change of summer load is analysed. Simulation results show the accuracy of the algorithm. In terms of power supply, the reserves of fossil energy are drying up. According to the prediction of authoritative organizations, the world's coal can be mined for 216 years. As a renewable energy, wind power has no carbon emissions compared with traditional fossil energy. At present, it is generally believed that wind energy and solar energy are green power in the full sense, and they are inexhaustible clean power. The model of wind power solar hydrogen hybrid energy system is established. The control strategy of battery power compensation for delayed power of hydrogen production is adopted, and different operation modes are divided. The simulation results show that the system considering the control strategy can well meet the load demand. Battery energy storage system is difficult to respond to short-term peak power fluctuations. Super capacitor is used to suppress it. This paper studies the battery supercapacitor complementary energy storage system and its control strategy. When the line impedance of each generation unit in power grid is not equal, its output reactive power will be affected by the line impedance and distributed unevenly. A droop coefficient selection method of reactive power sharing is proposed. Energy storage device is needed to balance power and maintain DC voltage stability in the DC side of microgrid. Therefore, a new droop control strategy is proposed. By detecting the DC voltage, dynamically translating the droop characteristic curve, adjusting the output power, maintaining the DC voltage in a reasonable range, reducing the capacity of the DC side energy storage device. Photovoltaic grid connected inverter chooses the new droop control strategy.

scholarly journals Optimal P-Q Control of Grid-Connected Inverters in a Microgrid Based on Adaptive Population Extremal Optimization

Energies ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 2107 ◽  
Author(s):  
Min-Rong Chen ◽  
Huan Wang ◽  
Guo-Qiang Zeng ◽  
Yu-Xing Dai ◽  
Da-Qiang Bi
Keyword(s):  
Constrained Optimization ◽  
Optimization Problem ◽  
Reactive Power ◽  
Active Power ◽  
Adaptive Genetic Algorithm ◽  
Constrained Optimization Problem ◽  
Extremal Optimization ◽  
Active And Reactive Power ◽  
Three Phase ◽  
Grid Connected Inverter

The optimal P-Q control issue of the active and reactive power for a microgrid in the grid-connected mode has attracted increasing interests recently. In this paper, an optimal active and reactive power control is developed for a three-phase grid-connected inverter in a microgrid by using an adaptive population-based extremal optimization algorithm (APEO). Firstly, the optimal P-Q control issue of grid-connected inverters in a microgrid is formulated as a constrained optimization problem, where six parameters of three decoupled PI controllers are real-coded as the decision variables, and the integral time absolute error (ITAE) between the output and referenced active power and the ITAE between the output and referenced reactive power are weighted as the objective function. Then, an effective and efficient APEO algorithm with an adaptive mutation operation is proposed for solving this constrained optimization problem. The simulation and experiments for a 3kW three-phase grid-connected inverter under both nominal and variable reference active power values have shown that the proposed APEO-based P-Q control method outperforms the traditional Z-N empirical method, the adaptive genetic algorithm-based, and particle swarm optimization-based P-Q control methods.

scholarly journals A new approach to three-phase asynchronous motor model for electric power system analysis

2021 ◽  
Vol 12 (4) ◽  
pp. 2083
Author(s):  
Laura Collazo Solar ◽  
Angel A. Costa Montiel ◽  
Miriam Vilaragut Llanes ◽  
Vladimir Sousa Santos
Keyword(s):  
Power Systems ◽  
Reactive Power ◽  
Mechanical Load ◽  
Asynchronous Motor ◽  
Electrical Power ◽  
Variable Load ◽  
Electrical Power Systems ◽  
Active And Reactive Power ◽  
Voltage Variation ◽  
Three Phase

In this paper, a new steady-state model of a three-phase asynchronous motor is proposed to be used in the studies of electrical power systems. The model allows for obtaining the response of the demand for active and reactive power as a function of voltage and frequency. The contribution of the model is the integration of the characteristics of the mechanical load that can drive motors, either constant or variable load. The model was evaluated on a 2500 kW and 6000 V motor, for the two types of mechanical load, in a wide range of voltage and frequency, as well as four load factors. As a result of the evaluation, it was possible to verify that, for the nominal frequency and voltage variation, the type of load does not influence the behavior of the powers and that the reactive power is very sensitive to the voltage variation. In the nominal voltage and frequency deviation scenario, it was found that the type of load influences the behavior of the active and reactive power, especially in the variable load. The results demonstrate the importance of considering the model proposed in the simulation software of electrical power systems.

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