Using the Suggested Switching Tool
You can use the Suggested Switching tool to generate a set of steps that can be inserted into a new switching sheet or appended to an existing switching sheet.
Appending Steps to an Existing Switching Sheet
If you want to add steps to an existing sheet, do the following before you run the Suggested Switching tool:
1. Start Web Switching Management.
2. Create or select a planned switching sheet to append the optimization plan steps.
3. Click the Record button to enable recording. (This is required in order for optimization steps to be appended from the wizard.)
Selecting Devices
1. Select one or more devices in the Viewer, based on the switching scenario you want to perform:
• Isolate Only: Select a single or multiple energized or de-energized devices. Optimum performance with multiple devices occurs if the devices are near each in the model.
• Isolate and Restore: Select a single or multiple energized or de-energized devices. Optimum performance with multiple devices occurs if the devices are near each in the model.
• Restore: Select a single de-energized device.
• Feeder Unloading: Select one or more devices that identify a single feeder.
• Violation Relief: Select one or more devices that identify a single feeder.
• Substation Switching: Select one or more devices of the correct type, such as power transformers or breakers.
Note: To select more than one device, press the CTRL key while clicking the devices in the Viewer.
Starting the Suggested Switching Tool
The Suggested Switching tool uses a wizard approach that steps you through a series of pages to gather input, generate plan options, and, finally, provide the results of the chosen plan for use in a new or existing switching sheet. To start the Suggested Switching wizard:
1. With devices selected, select Suggested Switching... from the Viewer DMS menu.
Understanding the Suggested Switching Tool Window
The Suggested Switching window is divided into three areas:
1. The Context Pane (left): shows the steps in the wizard. Completed steps are shown in normal text, the current step is bolded, and the remaining steps are grayed out.
2. The Main Pane (right): provides the user options or results of wizard.
3. The Button Pane (lower): contains the following buttons:
• Back: Moves the wizard back to the previous page.
• Next: Moves the wizard to the next page, as listed in the context pane on the left side of the window.
• Cancel: closes the Suggested Switching wizard. (Note that any selections or changes made to parameters on any of the pages will be lost.)
• Help...: Opens the online help system to the Suggested Switching tool help content.
Selecting a Plan Type
Plan Type is the first page of the Suggested Switching wizard. It allows you to select the type of suggested switching operation to perform and whether only SCADA devices should be used in the plan.
1. Select a Plan Type
Note: Once a Plan Type is selected, the context pane will be updated to list the applicable pages in the wizard.
Note: The Plan Types options will be desensitized if they are not valid for the selected devices.
2. Click Next to proceed to the next step in the wizard.
Unload Feeder
The Unload Feeder page allows you to modify values for load to transfer from the feeder to adjacent feeders for each phase. The Unload Feeder page is only available when the Feeder Unloading plan type is selected.
1. Enter the load capacity in amps for A phase, if applicable.
2. Enter the available load capacity in amps for B phase, if applicable.
3. Enter the available load capacity in amps for C phase, if applicable.
4. Click Next to proceed.
Load Scenario
The
Load Scenario page is used to verify or modify the power flow load and limits scenario, which will be used to determine the best plan options. When the window opens, the default values for load profile, temperature, scaling factor, and limits are visible in read-only mode; to change the scenario, click the
Modify button to open the
Power Flow Study Mode Load Scenario dialog box (see
Understanding the Power Flow Study Mode Load Scenario for details).
1. View and modify the load scenario, as necessary.
2. Click Next to proceed to the Constraints page.
Constraints
Constraints determine acceptable system conditions for the suggested switching results.You can constrain the algorithm that determines the plan by selecting from the following options:
• Only use SCADA devices: select to constrain Suggested Switching to only consider SCADA operable devices for the switching plans. This allows you to create plans that can be operated from the Control Room without sending a crew to the field.
• Exclude devices with inhibit tags: select to constrain Suggested Switching to switches with no inhibit tags. The inhibit tag classes are configured via the Suggested Switching, Inhibit Classes rule in the Configuration Assistant, Event Management tool.
• Minimize impacted area with non-load break switches will cause Suggested Switching to include non-load devices in the plan. Intermediate steps will be added to first de-energize the non-load device for operation, and then subsequently reverse the intermediate steps.
• Allow dispatch DG to achieve objectives will cause Suggested Switching to include the dispatch of controllable DER resources to achieve desired results.
• Allow shed load to achieve objectives will cause Suggested Switching to consider scenarios where load can be dropped to prevent overloads from occurring.
• Disconnect DG (IEEE-1547 rules) will cause Suggested Switching to emulate DER disconnections during recent re-energization events. Therefore, in Restore scenarios, DER devices will be disconnected for the purpose of evaluating load.
• Cold load pickup will cause Suggested Switching to increase the load in de-energized areas for Restore scenarios. The amount of increase is determined by the Cold Load Pickup Percent rule available in the Configuration Assistant.
• Evaluate protection reach violations will enable protection reach and unprotected device violations to be generated. These are only evaluated for the plan as a whole (as opposed to individual steps) and are only visible on the Feeder Summaries in the plan details.
• A Protection Reach violation is a protective device that doesn't provide adequate protection for all devices downstream.
• An Unprotected Device violation is a device that is not adequately protected by the immediate upstream device.
• Force kVA engine will cause Suggested Switching to perform a kVA based analysis on the load flows even if the section of the network is configured to use Power Flow solutions. kVA solutions are faster, but they do not analyze voltages so low/high voltage conditions will be missed.
Once you have selected the constraints, click Next to proceed.
Feeder Ties
The Feeder Ties page displays a list of tie switches to feeders that are adjacent to the selected feeder. Various details about the tie switches are displayed including:
• Tie Switch: the name of the tie switch.
• Feeder: the name of the feeder.
• Substation: the name of the substation that supplies the feeder.
• Tie Capacity: the tie switch and the upstream supply.
• Fdr Capacity: the capacity of the feeder.
• Distance: distance to feeder head.
• Avg Volt: the average voltage.
• Min Volt: the minimum voltage.
• Solution Mode: the load flow solution mode (that is, Power Flow or kVA) used to calculate the data.
The tie switches are listed the table in priority order.
1. If you do not want a feeder to be used for load transfers, uncheck the box in the Use column.
2. To view a switch in the Viewer, select the switch in the list and click the View... button.
3. To change the priority order of the tie switches, select a tie switch in the list and click the Move Up or Move Down button, as applicable. Switches higher in the list are given higher priority.
4. Click Next to proceed.
The suggested switching algorithm computes the suggested switching plans based on settings from all the wizard pages that have been filled in to this point.
To direct the search for the best suggested switching plan, all of the tie points are given a rank between 0 and 1. Zero represents the least favorable tie point and one represent the most favorable tie point.
The rank of a tie point is determined by aggregating the weighted scores of various parameters such as minimum voltage, average voltage, distance to feeder head, and so on. The score of the parameter is multiplied by the weight of the parameter to get the weighted score of the parameter.
Plans
The Plans page displays a list of plans generated by the Suggested Switching tool and overview information for each plan.
• # Steps: is the number of switching steps in the plan.
• Affected Feeders: lists the feeders affected by the plan.
• Affected Switches: lists the switches affected by the plan.
• Customers Impacted: summarizes the number of regular and critical customers that are impacted by the plan. The counts are further divided into customers that are fully impacted and those that may be temporarily impacted by intermediate steps to allow non-load break operations.
• Affected DERs: summarizes the number of primary and secondary distributed energy resources (DERs) that are impacted by the plan. DERs, which can form island and act as source, are defined as primary.
• Violations Before: the number of violations before the plan is implemented.
• Violations After: the number of violations if the plan is implemented.
Note: You may stop the system from generating additional plans by clicking the Stop Solution button. The button is only available when the system is still processing solutions (that is, neither the Maximum Number of Plans or the Maximum Time to Search have been reached).
To view detailed result data and steps for a plan, select the plan in the Plans list and click the Plan Details.... button, which will open the Suggested Switching Plan Details window.
Suggested Switching Plan Details
The Suggested Switching Plan Details window provides information about the plan's switching steps and feeder status.
• Switching Steps Tab: The Switching Steps tab shows the individual switching steps and the effects of each switching step on the feeder where its load is being transferred Associated switching step violations and affected DERs are shown to the right.
• Switching Step Violations: Tree view is displayed with the total number of violations in feeders and type of each violation along with associated device.
• Affected DERs: Tree view is displayed with the total number of affected DERs in feeders with type and its information.
• Feeder Changes Tab: The Feeder Changes tab shows the net effect of all switching changes on each of the affected feeders. This view clearly shows the net change in violations and affected DERs before and after all switching steps are performed.
Click Close to return to the Plans page.
1. Once you have decided which plan to use, select it in the Plans list.
2. Click Next to proceed to the Summary page.
Summary
The Summary page displays the selected plan's Switching Summary for your review and allows you to insert or append the switching steps into a switching sheet.
• To save these steps in a new switching plan, click the Create Plan... button. The wizard closes, and a new planned switching sheet opens in the Web Switching Management window. The newly generated plan's Request tab will be populated with all relevant device related data.
• To insert these steps into a currently open switching sheet, click the Append Steps... button. The steps are inserted into the open sheet in the Web Switching Management window.
See
Planned Switching for more information about Web Switching Management.