Stochastic Optimization of PQ Powers at the Interface between Distribution and Transmission Grids

Round 1

Reviewer 1 Report

 Due to DG's increasing active output in the distribution network and the length of the underground cable, regional voltage regulation is more difficult. This work uses two time-scales voltage regulation control methods, daily control of CBs to extend the life of the taps, and hourly control for the DG to control the voltage more precisely. The hybrid control method has the advantages of two control methods and has a strong industrial application adaptability. The article describes scientific issues as clear and simple. But there are still some minor problems.

2.1 Figure 3: What does the color code mean, and is this topology from a real grid?

2.2 Line 155: Why is the droop coefficient = -0.35, is there any mathematical or reference support?

2.3 Line 206: DGs based on power electronic devices responds very quickly, and theoretically can control active and reactive power more precisely. Undesirable PQ diagrams can be avoided as long as the control sits in the right way and the parameters are appropriate.

Why is the control interval of DQ for up to 1 hour in this work?

Why the undesirable PQ diagrams can avoid as long as the control interval reaches 1 hour?

Author Response

Please see the attachment

Author Response File: Author Response.pdf

Reviewer 2 Report

This paper proposes a method for making optimal decisions regarding the reactive power of the DG units in distribution networks to achieve the desired voltage profile. 

Some questions to improve the paper

1- Is the PQ curve specified in Fig 2 correct?

it means that the DG can operate at P=0.2Pmax and Q=0.4Pmax 

in this case, Power factor would be P/S=0.2/(0.04+0.16)^0.5=0.44 ! 

2- What does DCC stand for ? 

3- In this paper it is assumed that the uncertain parameters follow a probability density function. What should be done if this info is not available? 
Some relevant works can be found in the literature 

Decision making under uncertainty in energy systems: State of the art,
Renewable and Sustainable Energy Reviews,
Volume 28, 2013,Pages 376-384. 

4- The following paper is close to what has been done in this work. Please discuss the differences

"Two-Timescale Multi-Objective Coordinated Volt/Var Optimization for Active Distribution Networks," in IEEE Transactions on Power Systems.
doi: 10.1109/TPWRS.2019.2914923

 5- Why is the load factor negative in figure 7 ? 

 

 

Author Response

Please see the attachment

Author Response File: Author Response.pdf