The Gujarat Hybrid Renewable Energy Park

The Gujarat Hybrid Renewable Energy Park is one of the world’s largest renewable energy projects, combining solar and wind energy on a massive scale. Here are the key details:

Overview

- Location: Kutch district, Gujarat, India  

- Total Planned Capacity: 30 GW (gigawatts)  

- Land Area: 72,600 hectares (approx. 726 sq km)  

- Developed by: Gujarat Hybrid Renewable Energy Park Ltd (GHPCL) – a joint venture between Gujarat government (Gujarat Power Corporation Ltd - GPCL) and private renewable energy companies

- Estimated Investment: Over ₹1.5 lakh crore (~$20 billion)  

Hybrid Energy Components

1. Solar Power – Large-scale photovoltaic (PV) plants  

2. Wind Power – Onshore and potentially offshore wind farms  

3. Energy Storage – Battery storage & pumped hydro to ensure stable supply  

Key Features

- World’s Largest Renewable Energy Park (once fully operational)  

- Supports India’s 500 GW renewable energy target by 2030

- Reduces carbon emissions by ~50 million tons/year

- Hybrid model ensures consistent power generation (solar by day, wind often at night)  

Progress & Timeline

- Phase 1 (2022-2025): 5 GW already under development  

- Full Completion: Expected by 2030

- Major Investors: Adani Green, Suzlon, ReNew Power, and other global players  

Benefits

✔ Boosts Gujarat’s green energy leadership

✔ Creates jobs & economic growth in Kutch

✔ Supports India’s net-zero emissions goal by 2070

✔ Attracts foreign investment in renewables

This project is a cornerstone of India’s transition to clean energy and positions Gujarat as a global renewable energy hub.

What happens if you supply 220V DC to the transformer

Supplying 220V DC to a transformer designed for AC input can cause serious problems, including potential damage or failure.

Here’s why:

1. Transformers Work on AC, Not DC

   - Transformers rely on changing magnetic fields (Faraday’s Law of Induction) to transfer energy from the primary to the secondary winding.

   - DC voltage does not change over time, so it cannot create a varying magnetic field.

   - Without a changing magnetic field, no voltage is induced in the secondary winding.

2. Consequences of Applying DC to a Transformer

   - High Current Draw (Almost Like a Short Circuit):

     - The primary winding of a transformer has very low DC resistance (only wire resistance).

     - Applying DC causes a large current to flow (since there’s no inductive reactance to limit it).

   - Overheating & Burnout:

     - The excessive current can overheat the windings, damaging insulation and possibly melting wires.

   - Core Saturation:

     - The transformer core can become magnetically saturated, further increasing current and heat.

   - Possible Smoke/Fire Risk:

     - If the transformer is not protected (e.g., by a fuse), it may burn out, smoke, or even catch fire.

3. Will the Secondary Output Any Voltage?

   - No, because DC does not create a changing magnetic flux.

   - The only voltage you might see is a brief spike when connecting/disconnecting DC, but this is not useful and can be dangerous.

4. Exceptions (Special Cases)

   - Some pulse transformers or flyback converters can handle DC pulses, but standard AC transformers cannot.

   - If you need to step up/down DC, use a DC-DC converter instead.

Conclusion

⚠️ Never apply DC to an AC transformer—it will likely overheat, burn out, or fail catastrophically. Always use the correct input voltage type (AC for traditional transformers).  

If you need to convert DC, consider using:

- Buck/Boost Converters (for DC-DC conversion)

- Inverters (to convert DC to AC first)  

PILOT WIRE PROTECTION

PILOT WIRE PROTECTION : 

For longer tie lines, the most common protection scheme is the pilot wire differential scheme, as shown in Figure 9-8. A fault (Fext) external to the circuit breakers (CB) will cause current to flow through the restraint coils (R) of ANSI Device No. 87L and little or no current to flow in the operating coils (OP).

 An internal fault (Fint) will cause current to flow through the operating coils, which will result in the opening (tripping) of both circuit breakers. 

PILOT WIRE DIFFERENTIAL RELAYING :

Pilot wire relaying is a form of directional relaying where the phase currents are compared over a pair of metallic wires or fiber optics. 

• Internal Faults: One of the network output voltages (VA) will reverse polarity. The current entering Bus A will be 180o out of phase with the current entering Bus B and probably not equal. VA and VB will also be out of phase and probably not equal. With the voltages opposite most of the current will flow through the operating coils resulting in a trip of both breakers  

• External Faults: The network output voltages have the polarity. The currents entering Bus A and leaving Bus B are equal and in phase; the voltages likewise. The polarity of VA and VB allows them to support a circulating current through the restraint coils and pilot wire and very little current through the operating coils -- the relays will not operate. 

• Pilot Wire Supervision: To detect pilot wire faults (e.g., shorts, opens, grounds, etc.) a continuous dc supervision current is applied to the pilot wire. If the pilot wires are shorted, false tripping can occur. Although it reduces the sensitivity of the protection, a fault detector is often used to prevent false tripping.

The increase of the circulating current initiates an alarm. Depending on the location of the short, one of the relays may not trip for an external fault. If the pilot wires are open no tripping can occur. The interruption or absence of the supervisory current also initiates an alarm.

The relay acts as an overcurrent relay if the pilot wire is open.