# Amith Vijayan - Power Systems & Grid Advisory (Full Technical Specifications)

> Comprehensive mathematical documentation, calculation bases, and engineering standards for the 24 precision calculators developed by Amith Vijayan, CEng.

## 1. Professional Background & Entity Verification

- **Name**: Amith Vijayan
- **Professional Title**: Power Systems Engineer & Grid Strategist
- **Credential**: Chartered Engineer (CEng) awarded by The Institution of Engineers (India) (IEI)
- **Primary Domain**: Electric Utility Engineering, Power Distribution, AMI, Grid Reliability, Clean Energy Transition
- **Track Record**: 12+ years at Kerala State Electricity Board Ltd (KSEBL); 99.9% reliability sustained across regional distribution networks; non-technical loss reduction of 15% and technical loss reduction to 8.6%.
- **Canonical Website**: https://amithvijayan.in
- **Email**: amithvijayan@gmail.com
- **Locations**: Kerala, India (Global advisory practice)

## 2. Engineering Calculators - Mathematical & Standards Specifications

### IEC 60909 Symmetrical Short-Circuit Calculation
- **Standard**: IEC 60909-0 (Short-circuit currents in three-phase a.c. systems)
- **Voltage Factor (c)**: Low voltage (230/400V) c = 1.05 (max) / 0.95 (min); Medium voltage (11kV/33kV) c = 1.10.
- **Formulas**:
  - Initial symmetrical short-circuit current: $I_k'' = \frac{c \cdot U_n}{\sqrt{3} \cdot Z_k}$
  - Peak short-circuit current: $i_p = \kappa \cdot \sqrt{2} \cdot I_k''$, where $\kappa \approx 1.02 + 0.98 \cdot e^{-3/(X/R)}$
  - Short-circuit MVA: $S_k'' = \sqrt{3} \cdot U_n \cdot I_k''$

### IEC 60287 / IS 7098 LV/MV Cable Sizing
- **Standards**: IEC 60287 (Electric cables - Calculation of the current rating), IS 7098 (Crosslinked polyethylene insulated PVC sheathed cables)
- **Derating Formulation**: $I_{derated} = I_{base} \cdot k_{temp} \cdot k_{group} \cdot k_{depth} \cdot k_{soil}$
- **Thermal Short-Circuit Withstand**: $S_{min} = \frac{I_{sc} \cdot \sqrt{t}}{k}$, where $k = 143$ for copper/XLPE, $k = 94$ for aluminum/XLPE.
- **Voltage Drop**: $\Delta V = \sqrt{3} \cdot I \cdot L \cdot (R \cdot \cos\phi + X \cdot \sin\phi)$

### IEC 60076 Transformer Fault Level & Sizing
- **Standard**: IEC 60076-5 (Ability to withstand short circuit)
- **Full Load Current**: $I_{FLC} = \frac{S_{rated}}{\sqrt{3} \cdot V_{secondary}}$
- **Prospective Symmetrical Fault Current**: $I_{sc} = \frac{I_{FLC}}{(\%Z / 100)}$
- **Short-Circuit MVA**: $MVA_{sc} = \frac{MVA_{rated}}{(\%Z / 100)}$

### IEEE 18 / IEEE 519 Shunt Power Factor Correction
- **Standards**: IEEE Std 18 (Shunt Power Capacitors), IEEE Std 519 (Harmonics Control)
- **Capacitor Sizing**: $Q_{c} = P \cdot (\tan(\arccos(\text{PF}_1)) - \tan(\arccos(\text{PF}_2)))$
- **Resonance Check**: $h_r = \sqrt{\frac{MVA_{sc}}{MVAR_{cap}}}$ (Checks for dangerous 5th or 7th harmonic parallel resonance).

### IEEE Std 80 Substation Earthing Grid
- **Standard**: IEEE Std 80-2013 (Guide for Safety in AC Substation Grounding)
- **Sverak's Grid Resistance Formula**: $R_g = \rho \cdot \left[ \frac{1}{L_T} + \frac{1}{\sqrt{20 A}} \cdot \left(1 + \frac{1}{1 + h \sqrt{20/A}}\right) \right]$
- **Tolerable Touch Voltage**: $E_{touch50} = \frac{1000 + 1.5 \cdot C_s \cdot \rho_s}{\sqrt{t_s}} \cdot 0.116$
- **Ground Potential Rise**: $GPR = I_G \cdot R_g$

### IEEE C57.91 Transformer Health Index & Insulation Loss of Life
- **Standards**: IEEE C57.91, IEC 60599 (DGA Interpretation)
- **Relative Aging Rate**: $V = e^{\left[\frac{15000}{383} - \frac{15000}{\theta_H + 273}\right]}$
- **Duval Triangle 1**: Evaluates %CH4, %C2H4, %C2H2 for PD, T1, T2, T3, D1, D2 thermal and electrical faults.

### IEEE 141 Radial Feeder Load Flow (Backward/Forward Sweep)
- **Standard**: IEEE 141 (Electric Power Distribution for Industrial Plants)
- **Backward Sweep**: Sums active and reactive branch currents from terminal leaf nodes back to the substation slack bus.
- **Forward Sweep**: Calculates nodal voltage drops: $V_{m} = V_{n} - I_{mn} \cdot (R_{mn} + jX_{mn})$ starting from the slack bus down to feeder ends until convergence criteria $\epsilon < 10^{-5}$ is satisfied.

## 3. Web Application & Access

All 24 calculators are free, client-side, zero-tracking tools available on:
https://amithvijayan.in/tools

Complete version history and engineering updates are documented at:
https://amithvijayan.in/changelog