Phase Balancing
 

Application Overview:

• See Phase Balancing Setup for details on user input options for this application.

• For general details on running an application, selecting and displaying output variables, see Running DEW Applications.  

• The Available Output Variables for the application are described in the last section of this topic.

Phase imbalance is calculated from line flows resulting from the Power Flow application.  

• Phase balancing calculations can be based on either power (kW) or complex power magnitude (kVA).  

Phase balancing will run for multiple circuits.  

• The imbalance will not be calculated at the substation, but at each start of circuit component.  

• Therefore, the resulting imbalance at the substation may not improve and could possibly be worse.

The Phase Balancing application recommends phase movements of single and two-phase laterals for all user selected circuits, making use of all time points selected for analysis.

• Typically, Phase Balancing should be run at the time of peak loading.  

• For multiple time point selections, analysis uses the average load over selected time points.

• The lateral movements are to improve the balance at the three-phase, grounded start of circuit component.  

• If the start of circuit component is ungrounded, i.e. delta connected, then phase balancing will improve the balance at all of the three-phase power transformers closest to substations grounded on the secondary side.

Application Run / Results:

See Running DEW Applications for general details on running an application, selecting and displaying output variables.  

The user may set limitations on laterals where re-phasing is allowed.  See Phase Balancing Setup for more details.   

The Phase Balancing application first establishes a baseline reference by evaluating the maximum phase imbalance at the start of circuit (or grounded transformers) and within the circuit over all time points specified for analysis.

• These imbalances are stored along with the corresponding times of occurrence.  

• Once the recommended phase movements have been determined, the maximum imbalances are once again evaluated.  

• These imbalances may then be compared, along with the times of occurrence, to the imbalances that existed before the Phase Balancing run.  

Phase Balancing locates all laterals in the circuit, determines the total flow through each, and disconnects them from the rest of the circuit so that only the three phase portion of the circuit (the spine) is connected to the start of circuit component.  

1. Laterals directly connected to the spine are reconnected one at a time in order of most to least loaded.  

2. All remaining laterals (single-phase laterals connected to two-phase laterals) are reconnected from most to least loaded.  

3. Each reconnection evaluates all possible re-phasing options and selects that which maintains the minimum imbalance at the start of circuit component.

Two output formats are available from the Phase Balancing application.  The user can generate the Phase Balancing Report, as well as cycle the displayed network through the output variables selected from the Analysis / Setup for Results Display menu.

Available Output Variables:

For general details on running an application, selecting and displaying output variables, see Running DEW Applications.  The output variables available for display from the Flicker Analysis application are described in the following table.