Introduction

MiPower® is driven by a robust power system analysis toolbox covering various aspects of power system studies from steady state analysis to stability and security assessment, including reliability and protection.
The toolbox caters to the needs of power system planners and operations engineers. Windows based platform makes it highly interactive and user-friendly. Professionally designed GUI and centralized databases add to the efficacy of the software tool.

Load Flow Analysis

Load Flow Studies is basic tool for power system analysis to assess the steady state performance of power system under various operating conditions. This also enables studies pertaining to the changes in power system network configuration. It determines the power flows,complex bus voltagesand losses of the power system for a given load and generation profile. The challenges of modeling very largenumber of components are taken care of by exploiting Sparse techniques.

The key features of the module are :

  • Gauss – Seidel (GS)
  • Newton Raphson (NR)
  • Fast Decoupled Load Flow (FDLF)
  • Voltage & Frequency dependentLoads
  • Multiple Island systems
  • Customized Report
  • Optimal Load Flow
  • AC/DC power flow (HVDC)
  • Modeling of FACTS devices
  • Modeling ofRenewable Energy (RE) devices (Wind and Solar converters)

The output of the load flow studies is used by other system studies like short circuit, stability, motor starting, contingency analysis etc.

MiPower Load Flow Analysis PRDC

Power Flow results on the Network

MiPower Load Flow Analysis PRDC

Power Flow Study Options

Harmonic Load Flow

With the increasing proportion of harmonic currents in the power system, Harmonic Load Flow performs conduct the harmonic assessment to compute Total harmonic distortion factors for voltages and currents in three phase system. Harmonic load flow also computes harmonic transfer impedance and driving point impedance for both transmission and distribution power systems.

Harmonic analysis is done using Harmonic Load Flow and Frequency Scananalysis.

The key features of the module are :

  • Computation of VTHD , ITHD , Telephone Interference Factor (TIF)
  • Modeling harmonic voltage and current source
  • Frequency Scan Analysis foruser-defined harmonic order
  • Computation ofpositive, negative and zero sequence harmonics
  • Transformer modeling with wide range of winding connections
  • Graphical view for visualization of bus wise VTHD , ITHD and Frequency Scan

The output of the Harmonic Load Flow is useful in design of filters to reduce the harmonics.

MiPower Harmonic Load Flow Frequency Scan Plot PRDC

Frequency Scan Plot

MiPower Harmonic Analysis Plot PRDC

Harmonic Analysis Plot

MiPower Harmonic Sample System PRDC

Harmonic Sample System

MiPower Total Harmonic Distortion Plot PRDC

Total Harmonic Distortion Plot

Short Circuit Analysis

Short circuit studies are conducted to determine the fault currents and fault MVA levels in the power system. The various types of short circuit faults, at any location in the system, include

  • Single line to ground(LG) fault
  • Line to line (LL)fault
  • Double line to ground (LLG) fault
  • Three phase to ground fault (LLLG).

The key features of the module are :

  • Symmetrical and Asymmetrical Faults
  • Modeling of Self and Mutual Impedances
  • Compliance to related ANSI/ IEEE/ IEC standards (including 363 & 909)

The selection of circuit breakers depends on the post-fault current (immediately after the fault) and the interruption current (which the breaker must interrupt). The results of the short circuit studies are often useful for determining the relay settings.

MiPower Short Circuits Analysis Options PRDC

Short Circuits Analysis Options

MiPower Short Circuits Analysis Results PRDC

Short Circuits Analysis Results

Network Reduction

Power systems are often very big networks and have localized impact of disturbances. Network Reduction Module provides the static and dynamic equivalents for the power system. These are normally used for studying the impact of the faults and disturbances on the key components in the time domain simulations like transient and dynamic stability analysis.

The key features of the module are :

  • Computation of Static and dynamic equivalents for the power system networks
  • Computation of YBUS and ZBUS
  • Static equivalent: YBUS basedreduction, seen from the desirednodes
  • Dynamic equivalent: Single machine equivalent of the power system

MiPower Network Reduction Options PRDC

Network Reduction Options

DC Network Solutions

The DC Network Solution is a module to analyze the DC power networks.

The key features of the module are :

  • D.C. Load Flow Analysis
  • D.C. Short CircuitAnalysis
  • Enables Battery Sizing

The DC network solution provides currents flowing through the branches in the network and the nodal voltages. The network topology, the resistances of the branches and the source in the network, source voltages and the loads are taken into consideration.

MiPower DC Network Solution PRDC

DC Network Study

Transient Stability Study

With the disturbances being the integral part of the power systems, it is vital for the system operator to understand the impact of these disturbances, from stability perspective, on the operational performance of the critical infrastructure like generators. The accurate transient response is critical for evaluation of the stability under large disturbances like faults.

The key features of the module are :

  • Supports LG/LL/LLG/LLL/ LLLG fault at user defined location
  • Detailed representation of
    • Turbines governors and Excitation systems (AVR)
    • Power System Stabilizers (PSS)
    • Static VAr compensators (SVC), HVDC controllers
  • Load Shedding as disturbance
  • Simulation of voltage / current / frequency and distance relays
  • Large Motor Starting Analysis

The studies enable the assessment of variations in operational parameters like Voltage, Current, generator frequency and rotor angle against limits. Remedial actions are planned accordingly.

MiPower Transient Stability Study TRS Configuration PRDC

TRS Configuration

MiPower Transient Stability Study Machine Voltage Plots PRDC

Machine Voltage Plots

MiPower Transient Stability Study Frequency Curves PRDC

Frequency Curves

Voltage Instability Analysis

With the exploitation of the network to it’s maximum due to resource constraints, the computation of the risk of voltage instability gaining importance. Voltage Instability analysis assess the proximity to the critical point (Loadability limit) and also computes the margin, under steady state conditions. The ranking of the load buses based on the L-index value indicate the weak buses in the system and the largest L-index value indicates the proximity to the system collapse point.

The key features of the module are :

  • Voltage instability assessment using L-Index and Centroid Voltage methodologies
  • Stability margin computation under steady state condition
  • Identify weak buses and areas in the system from Voltage Instability perspective

PV and QV curves are plotted for better visualization.

MiPower Voltage Instability Analysis PRDC

Voltage Instability Analysis

MiPower Voltage Instability Analysis PV-Curve PRDC

PV-Curve

Dynamic Stability Analysis

Dynamic stability indicates the ability of synchronous generators to adjust to small changes in load. The moving generators oscillate due to load change and normally settle to new values. It is important to analysis the generation oscillations and power swing oscillations to understand the small signal or dynamic stability. The amplitude and frequency of oscillations depend on the operating condition and inertia of the system.

The dynamic stability analysis is carried out in Frequency domain (Eigen value analysis) and Time domain with slow disturbances.

The key features of the module are :

  • Identification of the mode of oscillation
  • Examine the most effective control location
  • Adjustment in control parameters to improve system damping
  • Simulate disturbances to understand potential risk of oscillatory instability
MiPower Dynamic Stability Analysis Configuration PRDC

Configuration

MiPower Dynamic Stability Analysis Output Options PRDC

Output Options

MiPower Dynamic Stability Analysis Eigen-values PRDC

Eigen-values

MiPower Dynamic Stability Analysis Study Result PRDC

Study Result

Electromagnetic Transient Analysis

Overvoltage’s stress the insulation of the equipment and often lead to equipment failure. ETA module is designed to perform the transient and dynamic overvoltage studies for the power system arising out of switching operations, faults and lightning surges.

The key features of the module are :

  • Computation of highest discharge currents and energy stresses for the protective equipment
  • Assessment of withstand levels of currents and voltages for protected equipment
  • Supports energization of lines, transformers and shunt elements
  • Computes Over voltages during fault inceptions and clearing of faults

The simulation is useful for appropriate insulation co-ordination, and design of protection schemes. Simulation studies also facilitate investigation of interference due to communication lines, hazardous coupling effect to personnel, livestock, and equipment.

MiPower Electromagnetic Transient Analysis Over voltage Study configuration PRDC

Over voltage Study configuration

MiPower Electromagnetic Transient Analysis Sample PRDC

Sample

MiPower Electromagnetic Transient Analysis Current Plots PRDC

Current Plots

MiPower Electromagnetic Transient Analysis Voltage Plots PRDC

Voltage Plots

Sub Synchronous Resonance

Series capacitors are often used in long transmission lines, at appropriate locations, to enhance the line loadability. Sometimes these series capacitors excite low frequency oscillations due to Sub Synchronous Resonance (SSR), and damage turbine-generator shafts.

Sub Synchronous Resonance computes the oscillations in current, voltage and generator torque at Sub Synchronous frequencies. The Nyquist plot enables the interaction between the designated generators and the network under consideration and defines the stability of the power system.

The key features of the module are :

  • Frequency response method
  • Multiple synchronous machines
  • Series compensation in transmission network
  • Detailed modeling of machine shafts and control loops
  • Mode shape computation for SSR/Stability evaluation

MiPower Sub Synchronous Resonance  SSR-Configuration PRDC

SSR-Configuration

MiPower Sub Synchronous Resonance SSR-Sample PRDC

SSR-Sample

MiPower Sub Synchronous Resonance Mode Plots PRDC

Mode Plots

MiPower Sub Synchronous Resonance Nyquist Plots for Omega Variation PRDC

Nyquist Plots for Omega Variation

State Estimation

State estimation deals with the real-time measurements to obtain the best estimate of the current state of the power system, based on the network connectivity, system parameters and the analog measurement as inputs. With the error minimization algorithm, state estimation algorithm provides consistent base case, used for further power system analysis.

Adequacy of the measurements is assured by observability analysis, required for successful run the state estimation.

The key features of the module are :

  • Standard Weighted Least Square (WLS) method
  • Bad data identification and suppression
  • Observability Analysis for RTU Locations

The output of the State estimation is estimated load, generation and voltage profile along with the real and reactive power flows. This is used for carrying out power system simulation like, load flow scenarios, real and reactive power optimization and security analysis.

MiPower State Estimation Measurement Data PRDC

State Estimation Measurement Data

Real Power Optimization

The optimum utilization of power system resources is always the highest priority of the system operators. The Optimal Power Flow(OPF) provides the optimum unit generation with the minimum overall cost of generation, while satisfying the transmission system constraints. The OPF is used in economic analyses of the power system by providing “bus incremental costs” (BICs). The BICs are useful to determine the marginal cost of power at any bus in the system.

Optimal power flow also computes the incremental or marginal cost of power transmitted/ traded between multiple power companies while satisfying the security constraints on to the internal networks as well as tie lines.

The following objectives can be set for the OPF :

  • Generation cost minimization
  • System loss minimization
  • Overload alleviation

The enables the system planners and operators with the optimum solutions expediting the decision making.

MiPower Real Power Optimization PRDC

Real Power Optimization

Reactive Power Optimization

To optimize the reactive power resources, Reactive Power Optimization module is aimed at improving the voltage profile of low voltage pockets in the system.

The objectives for the reactive power optimization are :

  • Alleviation of the system bus voltages
  • Enhance voltage stability or loadability

Using the control variables are :

  • The transformer tap settings (T)
  • The generator excitation settings (V)
  • The switchable and controllable VAR compensator

MiPower Reactive Power Optimization PRDC

Reactive Power Optimization

Economic Dispatch

In operating the system for any load condition, the contribution from each plant and from each unit within a plant must be determined so that the cost of delivered power is minimum. The methodology used during economic scheduling is to minimize the total cost (generation + loss) with the generation schedule being considered within specified minimum and maximum generating limits.

Economic operation of power system deals with sharing the total load to minimize the overall generation cost. It also includes dividing the generations optimally to reduce losses in the system.

The output of the program gives the schedule of the generators and the overall cost.

MiPower Economic Dispatch PRDC

Economic Dispatch

Contingency Ranking & Analysis

Load flow analysis performs static security analysis for a given system so that the system is operated defensively. Due to contingencies, the system operations may enter into emergency state, wherein the operator has to take fast actions to restore the system back to normal.

Contingency definition accommodates all types of equipment outages and also the combination of them. The outage scenarios are studied using robust load flow analysis.

The contingencies are ranked based on :

  • voltage performance index (PIV)
  • overload performance index (PIF)

The worst case scenario will be top ranked having highest number of voltage and line loading violations.

The output of the contingency analysis is used for security assessment and enhancement.

MiPower Contingency Ranking & Analysis PRDC

Contingency Ranking & Analysis

Over Current Relay Coordination

Power system protection study deals with precautionary measures to be taken to safeguard the power system during abnormal operating conditions which involves periodic fault studies followed by relay setting, checking and coordination studies. Power System Protection can be current graded or time graded or a combination of both. The equipments in a power system need to be protected against faults which are external or internal faults. The schemes are broadly classified as unit protection schemes and graded (Time/Current) protection schemes.

Over current relay coordination studies provide Plug and time settings for appropriate functioning of protective relays with proper discrimination. This assures required reliability, sensitivity and selectivity of power system equipment.

The over current relay coordination study gives :

  • Plug Settings – for the phase/ earth relays
  • Time dial settings – for the phase/ earth relays
  • Instantaneous setting – for the phase/ earth relays
  • Primary and Backup Pairs

The output of the module provides the coordinated settings of the relays. These can be viewed in the form of graphs and reports. User defined settings also can be verified for the system. The co-ordination curves can be viewed and checked for the proper coordination.

MiPower Overcurrent relay co-ordination PRDC

Overcurrent relay co-ordination

Distance Relay Coordination

The distance protection is the most widely spread protection in transmission and sub-transmission networks. Distance relay responds to the ratio of measured voltage and current and operates if measured impedance (V/I) is less than the threshold value. Typically, distance relays are provided with multiple zones of protection to meet the stringent selectivity and sensitivity norms.

The key features of the distance relay coordination algorithm are :

  • Phase loop and earth loop impedance settings as per relay make and model
  • Load encroachment settings
  • Power Swing Blocking settings
  • Arc and Tower footing resistance
  • Impedance seen by relays for given fault location and type

The simulation output is also used for validation of user-defined settings.

MiPower Distance relay co-ordination PRDC

Distance relay co-ordination

Unit Protection Schemes

Unit protection schemes are used for protecting components like transmissions, transformers, bus bars, generators etc or a zone/sub-system. It does not involve time grading and relatively faster in operation. Unit protection is usually achieved by means of comparison of quantities at the boundaries of the zone.

Unit protection algorithms provide the settings for the relays used in :

  • Transformer Differential Protection scheme
  • Line Differential Protection scheme
  • Bus bar Differential Protection scheme
  • Partial Bus bar Differential Protection scheme
  • Generator Protection scheme
  • Restricted Earth Fault

MiPower Unit protection Schemes PRDC

Unit protection Schemes

ARC Flash

Safety being the key concern, Arc Flash Analysis provides limiting values of arcing current and incident energy to define the safe boundaries for the working personnel in the electrical installations.

The analysis determines the following :

  • Arcing current
  • Incident energy
  • Hazard Risk Category (HRC)
  • Personal Protective Equipment (PPE) requirements in an electrical system

The following standards are referred to compute safety requirements :

  • IEEE 1584-2002a
  • NFPA 70E 2012

The output of the Arc Flash Analysis provides the safety label which showcases the necessary information/ warning details for the safe working distance and the PPEs to be used.

MiPower ARC Flash Configuration PRDC

Configuration

MiPower ARC Flash Sample Report PRDC

Sample Report

Load Forecast

Load forecast is used to predict the energy demand during the planning stages of a power system. The robust multivariate regression technique is used for forecasting the energy demand accurately. The models are built based on the historical data.

The salient features of load forecast are :

  • Versatile load models
  • Best model selection for regression analysis

The output of the load forecast is used as an input to following studies.

  • Generation and transmission capital investment
  • Spinning reserve planning
  • Planning of fuel ordering

MiPower Load Forecast Data PRDC

Data

MiPower Load Forecast Result PRDC

Result

Ground Grid Design

This module is designed to compute the substation ground grid. The program conforms to ANSI and IEEE Guide for Safety (80-2000) in AC Substation Grounding. Ground Grid Design(GGD) module has been built, especially for utilities and industries, to design an economic and safe grounding grids. The tool is also used for checking adequacy of existing grounding grids for possible reinforcement. The GGD has efficient and well-proven analysis algorithms, User-friendly data entry and graphical 2-D plotting.

The key features of the module are :

  • Economic Design of EHV Grounding Grids
  • Use of standard ANSI/IEEE 80-1986/2000 Methodologies
  • IEC TS 60479 Compliant
  • IS 3043-1986 Compliant
  • 2-D Potential profile plotting

The output of the tool helps in analyzing earth potentials and enables engineers to choose a technically sound and economical design of grounding grid from a variety of options.

MiPower 2D Voltage Profile Plotting PRDC

MiPower 2D Voltage Profile Plotting

MiPower GGD MAT PRDC

GGD MAT

Battery Sizing

Battery sizing is a tool to determine the number of cells and cell size of the battery for a designated duty cycle such that it satisfies the maximum system voltage during the battery charging period and minimum system voltage during battery discharging period. The number of cells/string is determined to provide sufficient power to the load cycle considering the minimum system voltage and minimum operating temperature. It also considers different factors that affect the battery performance, such as design margin, aging compensation, initial capacity, etc.

The key features of the module are :

  • IEEE Standard 485-1997 compliant.
  • Computes number of cells and size for designated duty cycle
  • Handles voltage and temperature constraints
  • Battery performance assessment for design margin and aging compensation.

The output of the battery sizing program provides the size of the battery for a given load pattern.

MiPower Battery Library PRDC

Battery Library

Line and Cable Parameter Calculation

Line and Cable parameter program computes overhead transmission line and cable parameters from the design data. Overhead transmission line is represented by an equivalent “Pi” model, having resistance and reactance in series and line charging susceptance equally divided at either node as shunt element.

Key features of line parameter program are :

  • Calculates positive and zero sequence parameters of the overhead lines and cables
  • Single and multi phase configurations with ground wires
  • Calculates the mutual impedance between power and communication lines
  • Skin effect is considered for transmission lines

The output of the program is used as input data for the modeling of the lines/ cables for system studies.

MiPower Line and Cable Parameter Calculation PRDC

Line and Cable Parameter Calculation

Available Transfer Capability

Available Transfer Capability program computes the measure of the transfer capability and available margin in the transmission network and suggests the system operations with various schedules of generators and loads participating in bilateral transactions to maintain an efficient, coordinated and economical distribution.

The key features of the module are :

  • Full AC power flow solution - accurately determines real and reactive power flows, bus voltages
  • An efficient Repeated Power Flow (RPF) is used for processing the large number of scenarios/ contingencies to assess ATC for each transfer capacity evaluation

The output of the tool is used by the utility to determine the available transfer capacity in the transmission network.

MiPower Available Transfer Capability PRDC

Available Transfer Capability

Open Access Feasibility

Open Access Feasibility (OAF) is done to minimize the losses which distribution licensees are facing due to inadequacy of cross subsidy surcharge. The transmission capacity available in the system is utilized to contract the low cost generation from point A to point B.

The key features of the Open Access Feasibility are :

  • Facility to model generators and loads entering into bilateral transactions
  • Utilizes the network for low cost generation
  • Determines the OAF for the given network for given load/generation profile

MiPower Open Access Feasibility PRDC

Open Access Feasibility

Reliability Assessment

With the electricity consumers having right to get reliable and quality supplies, gaging such indices is important for distribution utilities. Reliability assessment tool computes such standard reliability indices which include SAIDI, CAIDI, SAIFI and CAIFI. These indices gage the performance and quality, and compared with the standard requirements.

The key features of the module are :

  • Computation of reliability indices like SAIDI,SAIFI,CAIDI, CAIFI
  • Report option with and without exclusions
  • Detailed report of reliability assessment
  • Graphical representation of the reliability indices

The output indices mainly represent the outage duration, outage frequency and number of consumers affected.

MiPower Reliability Assessment PRDC

Reliability Assessment

Automatic Single Line Diagram Generation

Automatic Single Line diagram Generation is an utility to generate the single line diagram of the electrical system. Input to ASLG is the MiPower® database file for the particular electrical system.

The key features of the module are :

  • Creates a single line diagram automatically for full or partial network.
  • Captures input directly from database

MiPower Automatic Single Line Diagram Generation PRDC

Automatic Single Line Diagram Generation

Free Programmable Blocks

A generalized modeling method for various system components in control system dynamic simulation is implemented in transient stability program. The program can accommodate models of varied degrees of complexity. The various components of control block is described to software by using elementary functions such as integrator, adder, multiplier, switch and simple non-linear functions.

The key features of the module are :

  • General purpose modeling tool for control blocks
  • Time domain response analysis
  • Customized design for generator AVR, governor, SVC, HVDC etc...
  • Compatible with Transient stability analysis module

MiPower Free Programmable Blocks PRDC

Free Programmable Blocks

COMTRADE Viewer

COMTRADE Viewer module is provided for the user to view the COMTRADE files both in numerical and graphical way. The COMTRADE viewer reads the .DAT file and .CFG file for the inputs and it displays the samples both in numerical as well as graphical format. The data display offers a high-resolution graphical interface for displaying, analyzing and manipulating analog and digital channels of an oscillography record or a periodic load file. Displayed channels are marked, zoomed, numerically processed and summarized.

The key features of the module are :

  • Graphical view of the COMTRADE files
  • Mathematical analysis and operations on data
  • High resolution graphical interface for clear display and analysis
  • Handles analog and digital channels of an oscillography record

MiPower COMTRADE Viewer PRDC

COMTRADE Viewer

MiPContour

MiPContour is a graphical tool which is used to draw a distance relay characteristics library. This tool is used to create a relay characteristics library as per the relay settings.

The key features of the module are :

  • Build a user defined distance relay characteristics for variety of relay characteristics
  • Supports all Vendor specific data format
  • Modifying relay characteristic to match particular scenario
  • Allowing to develop user defined characteristics
  • Accurate visualization of the relay characteristics on one platform

MiPower MiPContour PRDC

MiPContour

AutoCAD Interface

AutoCAD Interface is a utility to convert the MiPower® Network to AutoCAD and to plot the results obtained using the MiPower® applications on an existing AutoCAD diagram. By invoking Network option, conversion of MiPower network to AutoCAD (.dxf file) file can be done. Results option helps the user to plot power system study results obtained from MiPower on AutoCAD network (.dxf file).

The key features of the module are :

  • Converts MiPower network diagram to AutoCAD
  • Facilitates the plots of results from MiPower® applications on AutoCAD

MiPower AutoCAD Interface PRDC

AutoCAD Interface

MiGraph – Multipurpose graphing tool

Graph utility is a module of MiPower® to view the results of MiPower® applications in linear, semilog and logs scale. The input to this module is the binary file/s generated from MiPower® applications. The selected graph from the binary file can be stored as graph files “grp”. Here window is split into two panes. In the first pane, the graph is plotted and the second pane contains a list having all the variables extracted from the binary file. X and Y-axis variables has to be selected from the list to plot the graph.

The key features of the module are :

  • Multiply X and Y column in same view
  • Quick mathematical operations on graphs
  • Custom color, thickness, symbols, fonts, number of symbols on curve etc...
  • Graphical relay coordination
  • Export graph DXF, data to text format

MiPower MiGraph – Multipurpose graphing tool PRDC

MiGraph – Multipurpose graphing tool

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