CEE Relays Ltd

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FAQs: What has changed in V5.0?
Note: This FAQ is a legacy from older updates to PTW.  For the very latest version of PTW, click here

Users of PTW version V5.0 will notice a lot of changes since the previous releases of PTW.  These are summarised below:

New Features: General PTW 
  • Project Scenario Manager 
  • Multi-Scenario Database Display and Editor 
  • Global Change Capability 
  • Support for multiple simultaneous users in a single project 
  • Expanded DXF Export Options 
  • Export Multiple Documents to DXF, WMF, Clipboard 
  • Form Print Export to DXF, WMF, Clipboard 
  • Xref Utility to update AutoCAD drawings with PTW schedules, one-lines and TCCs. 
  • Custom Arc Flash Label 
  • Arc Flash Line-side Report 
  • Arc Flash Special Instantaneous Zone Protection (Differential, Zone Interlocking, Optical Sensors, etc.) 
  • Group Print to PDF 
  • Expanded Protective Device Library 
  • Expanded Switch Library 
  • Expanded Transmission Line Library 
  • Link from TMS Motor Plot to CAPTOR TCC 
  • New Motor Damage Curves 
  • New Generator Overload Curves 
  • Typical Impedance Data for Motors and Transformers 
  • Copy/Paste Text Blocks on one-lines 
  • Copy/Paste Components between existing one-lines 
  • Global changes for TCC display options 
  • Expanded Relay modelling in I*SIM 
  • Expanded I*SIM switching events and plot channels 
  • New Frequency converter model in I*SIM. 
  • New option in A_FAULT to follow IEEE 141 Table 4-2 Multipliers 
  • Meter component for integration with on-line data and SCADA systems 
  • Expanded DAPPER load flow module to include transformer LTC 
  • Optional DMS Load Flow to compare meter data with system model 
  • Optional State Estimation study module 
  • Optional Optimal Power Flow study module 

Project Scenario Manager 
The scenario manager allows you to store multiple scenarios for each project. Changes made in the base project may be automatically promoted to all of the scenarios. Study results are stored with each scenario for comparison reporting. 
The scenario manager is accessed through the Project menu or the Scenario Manager button on the Component Editor. 
  • Clone/Create a new Scenario starting from the Base Project, or any of the existing Scenarios. 
  • Make any existing Scenario as the Base version and delete all other Scenarios. 
  • Delete the selected Scenario. Base Project can't be deleted. 
  • Rename the selected Scenario. Base Project can't be renamed. 
  • Promote base changes to the Scenario. 
  • Promote a Scenario to the base project. 
Once you're in a new Scenario, you can make any combination of changes including component state, connections, input data changes, adding new components, deleting existing components, etc. 
Scenario Manager Options: 
  • Add Scenarios using the Clone button. The clone button will duplicate the selected scenario and assign a default name. 
  • The Rename button allows you to enter a descriptive name for the scenario. 
  • The Delete button deletes the selected scenario. You can not use this function to delete the Base Project. 
  • Promote to base allows you to replace the base project with one of the scenarios. This option will delete all of the other existing scenarios. 
Changes made in the base project may be promoted to the scenarios with the following options: 
  • Promote changes only for fields that have not been modified in the scenario. For example, if you modified the length of cable C1 in scenario1 and later modified the length of cable C1 in the base project, the new length is stored in the base project and updated in all scenarios except scenario1. 
  • Promote all changes made in the Base Project to all Scenarios. Any component-level change made in the base project is automatically made in each scenario. 
  • Do Not Promote Base Changes to Scenarios. 
  • The Component Editor with any Scenario activated (except the base) can help identify components that have been changed or added in the Scenario. 
  • Show all components that have been modified (different than what's in the Base Project) in the "Diff" set. 
  • Colour-coded the fields in the Component Editor that are different than what's in the base. 
  • Show all components that have been newly created in the scenario. 
Data Visualizer compares data from different versions 
The Data Visualizer is a 3-dimensional database viewer and editor. Any combination of fields for any combination of components from any number of project scenarios can be displayed and edited. 
  • Select any number of scenarios to compare data 
  • Apply any datablock format to combinations of data fields from selected scenarios. 
  • Run Queries to select components for display. 
  • Option to list data by Component or Attribute. 
  • Option to Replace or Append/Merge the newly selected/queried components. 
  • Jump to the next component/attribute or the next component type. 
  • Print the display or save to Excel. 
  • Modify project input data directly in the spreadsheet display. 
  • Modify data for multiple components in one single action by Global Change. 
  • Open multiple Data Visualizer windows for comparisons. 
  • Save the layout, selected components, selected scenarios, datablock format, etc. as a Data Visualizer format. Recall any existing format. 

Enhancements to DXF, WMF, and Clipboard Export 
  • Single-layer one-line DXF conversion. 
  • Multi-layer one-line DXF conversion. 
  • Single-layer TCC DXF conversion. 
  • Export multiple One-lines, TCCs, Schedules, and Report files in a single action. 
  • Export Form-Print Layouts 
  • Xref AutoCAD utility to dynamically update PTW Schedules, One-lines and TCC drawings in AutoCAD. 
Enhancements to Arc Flash Evaluation 
  • Added Arc Flash Current Limiting equation capability in Protective Device library. 
  • Calculates Arc Flash incident energy and flash boundary based on the user-defined current limiting equations when available. 
  • New Protective device Line-Side report. (Assumes working at the line side protection and uses the next upstream device to trip). 
  • User definable colours for each PPE class for Bus Detail and Bus Label reports. 
  • New "Descriptions" field in the Bus component to report Zone or Area in Arc Flash labels. 
  • Enabled Go-To and Query Selections for Arc Flash, which can limit or select buses shown in Arc Flash Table. 
  • Custom Arc Flash Label format. To reach the custom label format editor, select the Bus Label button on the Arc Flash Evaluation window.  
Enhancements in CAPTOR - TCC 
  • New segment named "Delay Band (I ^ Slope - T) with Current & Time Settings", defines a line at a given slope and a given point defined by Current Setting at X multiple of the LTPU, CT Ratio and Time Setting in seconds. 
  • New Generator Relay capability with Adjustable minimum pickup and min/max time limits. 
  • Store TMS results for motor starting current with the motor component with new option to plot it on CAPTOR-TCC. 
  • Replace the motor Stall Point with Rotor Damage Curve. (If only one point is entered in the curve, it will plot as a single point similar to stall point) 
  • New motor Stator and Rotor Damage Curves. 
  • New generator Overload curve. 
  • Field Forcing Limit to start the generator decrement curve at a time other than 100 seconds. 
  • Option to place the TCC generator damage point at a user defined per unit current. 
  • Navigate from a selected protective device on the one-line/CE to the appropriate TCC. Navigation uses the Window > Find in TCC menu function. 
  • Component "Existing" dialogue support selecting multiple components to the TCC. 
  • Global change options for the current TCC or all TCCs in entire project to turn on/off Device Label, SC Flag, Pickup Label, Cable Ampacity Flag, Transformer FLA Label, Generator Rated Amps Label, and TCC Datablocks (with an option to apply the datablock attributes from the selected curve to all curves). 
  • Updated TCC Crystal Report formats to include settings for all functions defined for each protective device. 
PTW Interface Enhancements 
  • Support for multiple simultaneous users in a PTW project. 
  • Multiple selection dialogue for adding "Existing" project components to a TCC or One-line. Previously you could only select one component at a time. 
  • Option for transformer impedance to be based on Nominal kVA or Full Load kVA. 
  • Group Print multiple forms to a single PDF. Previously a separate file name was required for each TCC. This feature requires the Acrobat Print driver from Adobe. 
  • One-line display grid for symbol alignment. The grid display is selected from the One-line>Grid menu. 
  • Function to copy text blocks and paste them to the same one-line. 
  • Option to export only the selected components from a one-line, or the components currently listed in CE (could be a set from query, etc.) 
  • Added "Typical" data for transformer X/R in the "%Z Calculator". The typical X/R values are based on rated size and can be found in graphical form in the IEEE Red Book. 
  • Starting power factor separated from the fault contribution X/R for induction and synchronous motors in order to run Load Flow study with the impact motor staring option. 
  • Ability to Copy/Paste components from a one-line to another populated one-line. Previously the target one-line had to be empty. Now you can paste to any one-line where the copied components don't already exist. This is particularly useful when merging multiple projects. 
Enhancements in A_FAULT 
  • New A_FAULT study option to follow Std 141-1993 Table 4-2 multipliers for combined network. 
The IEEE 141-1993 Combined network table contains a different set of motor multiplying factors than those originally provided in the ANSI C37 standards. 
Enhancements in DAPPER Load Flow 
  • New load flow option to include Transformer Load Tap Changer (LTC) representation. The transformer taps will adjust automatically within the defined constraints to hold the voltage at the specified control bus. 
Enhancements to DAPPER Panel / MCC Schedules  
  • New schedule report formats with load quantity included. 
  • New DXF Export capability and Xref AutoCAD utility to keep CAD drawings current. Using Xref, the AutoCAD drawings store a reference to an existing schedule. Each time the AutoCAD drawing is opened, the most recent schedule from PTW is displayed. 
I*SIM Enhancements 
New Relay models in I*SIM, all models can sense voltage or current from anywhere in the system, and trip any branches, loads or motors. 
Relays include: 
  • Time Inverse Overcurrent 
  • Under Voltage Relay. 
  • Under Frequency Relay. (Trips individual loads, previously only tripped percentage of static loads at the bus.) 
  • Power Rate of Change 
  • Frequency Rate of Change 
  • MHO Distance Relay. 
  • Impedance Distance Relay 
  • I*SIM dynamic simulation expanded to use zero sequence network as well as positive sequence network. 
Expanded I*SIM channel display to include: 
  • Branch P + j Q (From), P + j Q (To) 
  • Branch I1 (From), I2 (From), I0 (From), I1 (To), I2 (To), I0 (To) 
  • Branch IA (From), IB (From), IC (From), IA (To), IB (To), IC (To) 
  • Bus voltage V1, V2, V0, VA, VB, VC, and all voltage angles. 
  • Machine Mech. Torque, Elec. Torque, Ed", Eq", Ed', Eq' 
New I*SIM Switching Events (disturbance types) 
  • Apply 3Phase, SLG, LLG faults to a bus. Previously only allowed 3Phase fault. 
  • Apply 3Phase, SLG, LLG faults to a bus. Previously only allowed 3Phase fault. 
  • Apply 3Phase, SLG, LLG, LL faults to anywhere along a branch. 
  • Trip 1, 2, or 3 phases anywhere along a branch. 
New I*SIM Frequency Converter Model 
  • Two separate systems can be defined and connected through a Motor-Generator Frequency Converter Model. The Frequency Converter allows you to specify the operating frequency on the generator side of the converter. Disturbances may be assigned and reflected in both systems. 
Distribution Management System (DMS) 
New Meter Component, reading meter measurement data from a SQL database. Some field service customisation is required for deployment of this feature. 
Option to refresh and display latest data from all meters on the one-line. 
Load Profile sub-view, store historical data for Loads and Motors. 
DMS Load Flow compares meter measurement data with PTW Load Flow results using existing load models, or Load Profile data. 
Branch loss calculations from meter readings. 
Branch impedance validation from meter readings. 
Distribution System State Estimation (balanced or unbalanced/single phase systems) 
The State Estimation program is a key component in the Distribution Management System since measured data from meters may have errors, and it is impossible to use meters to measure every power system state. The State Estimation program estimates all the state variables by using measured data and pseudo-measured data based on the users models. 
The basic idea of state estimation is to "fine-tune" system state variables by minimising the sum of squares of the differences between the estimated and measured power system data (real power P, reactive power Q, voltage V and current I). The Weighted Least Square (WLS) approach is used to get the optimal estimated load flow results. 
Most State Estimation is based on the balanced 3-Phase model. SKM's State Estimation program is specifically designed to handle unbalanced 3-phase or single-phase systems.  
Both P, Q, V measurement set and I measurement set are used in our State Estimation. 
Pseudo-measurement data are used to improve the accuracy when no meters are available at load buses. 
Optimal Power Flow (balanced or unbalanced/single phase systems) 
The Optimal Power Flow program obtains the load flow solution to minimise the selected objective function while satisfying all constraints. The constraints could be balancing the bus active and reactive power, satisfying lower and higher limits of bus voltages and generator active and reactive power outputs, etc. 
The Interior point method (IPM) is used to get the optimal power flow solution. 
Available objective functions are:  
  • Minimise Generation Cost  
  • Minimise System Active Power Loss  
  • Minimise System Reactive Power Loss  
  • Minimise Total Active Power Generation 
  • Minimise Total Reactive Power Generation 
  • Minimise New Shunt Mvar Devices Cost 
Transformer taps, generator P and Q could be adjusted to get the optimal power flow solution. 
Most Optimal Power Flow programs are based on the balanced 3-Phase model. SKM's Optimal Power Flow program is specifically designed to handle unbalanced 3-phase or single-phase systems.