Hello, I use csv file to play back ZIP load profile. When I test contant current load, I find the reactive power from meter mismaches a lot with power factor I set for the load. The load 671 is monitored and record results as csv file. The glm file, csv player file and result are attached.
Please help look at what is the problem. Appreciate your time!
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Are you remembering to correct for a delta configuration (the load model is in a line-to-line configuration, not a line-to-ground)? The measurements coming from the meter, however, are line-to-ground.
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Thank you for your reply. The meter is used to measure load 671 active and reactive power. From the exported measurements csv file, you can find the reactive power (484kVar ) is larger than active power(287kW) while the load 671 was set as constant current load and power factor is set as 0.868. That is my confusion about power factor. I need your help to find the reason why reactive power seems abnormal with power factor 0.868.
Would the connection of load will affect the power factor measured by meter? Or I have some unknown setting in glm file?
Thank you for your help!
The following code is copied from glm file about load 671 measurements
object meter {
name meter671;
phases ABCN;
nominal_voltage 2401.7771;
Yes, having your load delta connected will definitely give you different solutions. If you'd like to connect the load in a line-to-ground format, then remove the 'D' from the phases:
object load:671 {
name 671;
phases "ABCD"; <--------
Right now, you have set a constant current with a fixed power factor line-to-line (you end up getting something that looks like a circulating current), so this will NOT look like a 0.868 power factor when you measure line-to-ground (as the meter is doing).
If you would like to refer to this comment somewhere else in this project, copy and paste the following link:
Hello, I use csv file to play back ZIP load profile. When I test contant current load, I find the reactive power from meter mismaches a lot with power factor I set for the load. The load 671 is monitored and record results as csv file. The glm file, csv player file and result are attached.
Please help look at what is the problem. Appreciate your time!
The attachments contain glm file, 5s interval load profile and recorded restult.
Thank you!
My GridLAB-D version is GridLAB-D 4.0.0-17448 (Keeler) 64-bit MACOSX RELEASE.
Thank you!
Hongda,
Are you remembering to correct for a delta configuration (the load model is in a line-to-line configuration, not a line-to-ground)? The measurements coming from the meter, however, are line-to-ground.
Hi Jason,
Thank you for your reply. The meter is used to measure load 671 active and reactive power. From the exported measurements csv file, you can find the reactive power (484kVar ) is larger than active power(287kW) while the load 671 was set as constant current load and power factor is set as 0.868. That is my confusion about power factor. I need your help to find the reason why reactive power seems abnormal with power factor 0.868.
Would the connection of load will affect the power factor measured by meter? Or I have some unknown setting in glm file?
Thank you for your help!
The following code is copied from glm file about load 671 measurements
object load:671 { name 671; phases "ABCD"; voltage_A 2401.7771; voltage_B -1200.8886-2080.000j; voltage_C -1200.8886+2080.000j; base_power_A LoadProfile.value*443424.176; base_power_B LoadProfile.value*443424.176; base_power_C LoadProfile.value*443424.176; power_pf_A 0.0; current_pf_A 0.868243; impedance_pf_A 0.0; power_pf_B 0.0; current_pf_B 0.868243; impedance_pf_B 0.0; power_pf_C 0; current_pf_C 0.868243; impedance_pf_C 0.0; power_fraction_A 0.0; current_fraction_A 1.0; impedance_fraction_A 0.0; power_fraction_B 0.0; current_fraction_B 1.0; impedance_fraction_B 0.0; power_fraction_C 0.0; current_fraction_C 1.0; impedance_fraction_C 0.0; nominal_voltage 2401.7771; };}
Hi Jason,
By the way, how could we measure line-to-line voltage and power?
Thank you,
Hongda
Hongda,
Yes, having your load delta connected will definitely give you different solutions. If you'd like to connect the load in a line-to-ground format, then remove the 'D' from the phases:
object load:671 { name 671; phases "ABCD"; <--------Right now, you have set a constant current with a fixed power factor line-to-line (you end up getting something that looks like a circulating current), so this will NOT look like a 0.868 power factor when you measure line-to-ground (as the meter is doing).
Hi Mr. Jason Fuller,
Thank you for your reply and detailed explanation! I see the connection raises circulating current.
Do we have line-to-line voltage and power measurements available through meter?
Thank you for the solution!
Hongda