How to charge the battery during simulation?

[TheASingh]

Dr. Cui,

How can I charge the ESD1 battery during simulation?
In below simulation, value of En is 0.1. And I ran the simulation for 10s.
At 10s, I updated Pext0 of ESD1 to -100. But still couldn't charge the battery.

Am I updating the correct variable?

[cuihantao]

Did you update it in place using the alter method?
Double check if the update was successful by checking Psum.

[cuihantao]

Please post code and case files that I can replicate the issue.

[TheASingh]

ieee14_dgprct1_solar_ESD1.xlsx

I have attached the above input file. And I haven't made any changes in the code files.

I tried one more time with tstep = 0.33, and I was able to see the change in pIG_y.
But when I tried with default tstep, I'm still facing the issue.

Below result is for tstep = 0.33

Below result is for default tstep e.g. 0.033

[cuihantao]

Sorry but I'm not sure; where to find the code?

[cuihantao]

Do you mean the example notebook file?

[cuihantao]

It would be really helpful if you can send a block of code that can run and replicate the issue. Thanks.

[TheASingh]

ieee14_dgprct1_solar_ESD1.xlsx
Please run the following commands one by one on Jupyter. And please use the above excel file as input.

1. Code for tstep = 0.33

import andes
from andes.utils.paths import get_case
andes.config_logger(stream_level=30)

Below you need to provide the path of the input file (excel sheet that I have provided)

ss= andes.load('C:/Users/ASingh/.conda/pkgs/andes-1.5.8-pyhd8ed1ab_0/site-packages/andes/cases/ieee14/ieee14_dgprct1_solar_ESD1.xlsx', setup=False, no_output=True)
ss.setup()
ss.PFlow.run()
ss.PVD1.Iqcmd.lim.allow_adjust

ss.TDS.config.tf = 1800
ss.TDS.config.tstep = 0.33
ss.TDS.config.shrinkt = 0
ss.TDS.run()
ss.TDS.plt.plot(ss.ESD1.pIG_y, a=(0), ylabel='Test', greyscale=True, grid=True, savefig=False)

2. Code for default tstep

import andes
from andes.utils.paths import get_case
andes.config_logger(stream_level=30)

Below you need to provide the path of the input file (excel sheet that I have provided)

ss= andes.load('C:/Users/ASingh/.conda/pkgs/andes-1.5.8-pyhd8ed1ab_0/site-packages/andes/cases/ieee14/ieee14_dgprct1_solar_ESD1.xlsx', setup=False, no_output=True)
ss.setup()
ss.PFlow.run()
ss.PVD1.Iqcmd.lim.allow_adjust

ss.TDS.config.tf = 1800
ss.TDS.run()
ss.TDS.plt.plot(ss.ESD1.pIG_y, a=(0), ylabel='Test', greyscale=True, grid=True, savefig=False)

Let me know, if you still not get anything.

[cuihantao]

Thanks! I will get back to you soon.

[cuihantao]

It appears to be a bug! The change in SOC is too small and swallowed by numerical errors. Let me fix it.

[cuihantao]

This issue is fixed in my develop branch. You can also use very large step sizes like tstep=2. Previously, it will force it back to 0.033.

A new version will be tagged soon. Thanks!

[TheASingh]

Thank you!

Please let me know when the new version is released and is ready to use.

[cuihantao]

The new version, v1.5.11 is out with this issue fixed. You can upgrade your package with conda update andes. Double check after the upgrade for the version number.

[TheASingh]

Thank you very much, the issue is resolved now.

[TheASingh]

I have another query.
What are the min and max values for pref0 to charge the battery?

The battery has following parameters:
En= 100
SOCinit= 0.05,
p0(of concerned PV tab item) = 0.1 (As I have 10 batteries, so for one battery, it will be 0.01)
pmax (of concerned PV tab item) = 0.1
pmin (of concerned PV tab item) = -0.5

1. I updated pref0 to -0.9 at 900s. (Straight line)
2. Updated pref0 to -0.01 at 1800s. (Started charging)
3. Updated pref0 to -0.02 at 2700s. (Straight line)
4. Updated pref0 to -0.005 at 3000s. (Started charging)

What are the min and max values for pref0 to charge the battery? And also is it correct way to charge the battery?

[TheASingh]

I further verified the impact of Psum and results are as follow:
SOCinit = 0.5, En = 100, p0 = 0.1 (combined of 10 ESD1s in PV sheet)

1. Updated Pext0 to -0.02 at 300s and ran the TDS (300s to 600s). Psum was -0.00939823 (Charging)
2. Updated pref0 to -0.01 at 600s and ran the TDS (600s to 900s). Psum was -0.0296964 (Straight Line)
3. Updated Pext0 to -0.01 at 900s and ran the TDS (900s to 1200s). Psum was -0.0196964 (Straight Line)
4. Updated Pext0 to 0 at 1200s and ran the TDS (1200s to 1500s). Psum was -0.00939823 (Charging)
5. Updated Pext0 to -0.02 and pref0 to 0.01 at 1500s and ran the TDS (1500s to 1800s). Psum was -0.00939823 (Charging)
6. Updated Pext0 to -0.01 at 1800s and ran the TDS (1800s to 2100s). Psum was 0.00029466 (Discharging)

My query is:
Is it the Psum only that determines Charging/Discharging/Straight Line? If yes, Please let me know what is the range of Psum for Charging, Discharging and Straight Line?

[jinningwang]

Psum should be the most related on that determine the Charging/Discharging of ESD1.

The implementation of ESD1 is basically adding an SoC module to the PVD1. As for PVD1, you can refer to its doc from PowerWorld.

Another possible factor is the protection function integrated into ESD1. It is controlled by recflag, to enable voltage and frequency recovery limiters. The picture is PVD1 control diagram, but ESD1 is similar to it. The module in red rectangles are the voltage and frequency recovery limiters.