scholarly journals Steady-State Assessment of the DG Impact on Voltage Control and Loss Allocation

10.5772/8879 ◽  
2010 ◽  
Author(s):  
Enrico Carpaneto ◽  
Gianfranco Chicco
Keyword(s):  
Steady State ◽  
Voltage Control ◽  
State Assessment ◽  
Loss Allocation

scholarly journals Model Predictive Voltage Control with Optimal Duty Cycle for Three-Phase Grid-Connected Inverter

2019 ◽  
Vol 2019 ◽  
pp. 1-13
Author(s):  
Shahrouz Ebrahimpanah ◽  
Qihong Chen ◽  
Liyan Zhang ◽  
Misbawu Adam
Keyword(s):  
Steady State ◽  
Duty Cycle ◽  
Tracking Error ◽  
Voltage Control ◽  
Sampling Period ◽  
Sampling Interval ◽  
Nonlinear Load ◽  
Three Phase ◽  
Switching State ◽  
Steady State Performance

This paper proposes a model predictive voltage control (MPVC) strategy with duty cycle control for grid-connected three-phase inverters with output LCL filter. The model of the system is used to predict the capacitor filter voltage according to the future output current for each possible switching state at each sampling period. Then the cost function for each prediction is determined and the switching state is selected. In the proposed method, two voltage vectors are applied during one sampling interval to achieve better steady-state performance. Finally, the optimal duration of the nonzero voltage vector is defined based on the duty cycle optimization, which is vital to the control system. The proposed strategy offers a better reference tracking error with less THD in linear and nonlinear load situations. The effectiveness of the proposed method has been verified by MATLAB/Simulink and experimental results exhibit a better steady-state performance with less sampling frequency.

Influence of the weight coefficients of measurements on the consistency of the assessment and calculation results of the power supply system steady-state operation conditions

2021 ◽  
Vol 25 (2) ◽  
pp. 172-182
Author(s):  
A. M. Glazunova ◽  
I. N. Kolosok
Keyword(s):  
Steady State ◽  
Power Supply ◽  
Power Supply System ◽  
State Assessment ◽  
The State ◽  
Steady State Mode ◽  
Test Circuit ◽  
Calculation Results ◽  
Control Equation ◽  
Weight Coefficients

The aim of this work is to develop an improved procedure for assessing the state of power supply systems based on adjusting the weight coefficients of measurements. To this end, non-linear optimisation methods were used. The control equations and the solution of the simultaneous linear equations were performed using the Crout method. The results of the calculation of the electrical power steady-state mode were considered as a reference. The lower the difference between the evaluation and steady-state calculation results, the higher the accuracy of the overall state assessment procedure. The problem of correcting the weight factors is set and solved as a nonlinear optimisation problem, where the optimisation parameters are taken as the dispersion of the measurements. The objective function was formulated as follows: to minimise the measurement evaluation dispersions that are part of a single control equation by maximising the active power measurements dispersion in the swing bus of the power supply system. In this study, limitations in the form of equation and inequality are monitored. The problem of optimising the dispersions is solved after the first iteration of the state assessment; starting with the second iteration, the state assessment is performed with new measurement weight factors. The calculations were performed on a 6-node test circuit. The control equations are drawn from the current measurements. The measurements data on the selected control equation of the test circuit are used to calculate the target function. The accuracy of the dispersions redistribution and their extreme values are controlled by the limitations. The results showed that, when adjusting the dispersion of measurements, the power assessments at all nodes are closer to the steady-state mode calculation results.

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