Create app.py

app.py

@@ -0,0 +1,88 @@
+import numpy as np
+import matplotlib.pyplot as plt
+import streamlit as st
+
+# Define the calculation function
+def calculate_relay_curve(tr_kva, tr_volt, ct_pr, ct_sec, fac, tms, i_f_fac, curve):
+    # Calculate transformer current
+    tr_curr = round(tr_kva / (tr_volt * np.sqrt(3)), 3)
+    pick = round(fac * tr_curr / ct_pr, 3)  # Pickup value in multiples of In
+    i_f = round(i_f_fac * tr_curr * fac, 3)  # Fault current in amps
+
+    # Select curve coefficients based on relay type
+    if curve == 'IEC Normal Inverse':
+        b_ = 0.14
+        a_ = 0.02
+    elif curve == 'IEC Very Inverse':
+        b_ = 13.5
+        a_ = 1
+    elif curve == 'IEC Extremely Inverse':
+        b_ = 80
+        a_ = 2.0
+    elif curve == 'IEC Long Time Inverse':
+        b_ = 120
+        a_ = 1.0
+    else:
+        st.error("Invalid Curve Selected.")
+        return
+
+    # Calculate fault trip time
+    try:
+        fault_time = b_ * tms / (((i_f * (ct_sec / ct_pr) / (pick * ct_sec)) ** a_) - 1)
+    except ZeroDivisionError:
+        st.error("Error: Division by zero in fault trip time calculation. Check input values.")
+        return
+
+    # Generate data for the relay curve (current vs time)
+    x_curr = np.linspace(pick * ct_pr * 1.1, pick * ct_pr * 5, 500)
+    y_time = []
+    for x in x_curr:
+        try:
+            time = b_ * tms / (((x * (ct_sec / ct_pr) / (pick * ct_sec)) ** a_) - 1)
+            y_time.append(time if time > 0 else np.nan)  # Avoid negative/undefined times
+        except ZeroDivisionError:
+            y_time.append(np.nan)
+
+    # Display results
+    st.write('### Results:')
+    st.write(f'**Rated Current:** {tr_curr} A')
+    st.write(f'**Pickup:** {pick} x In')
+    st.write(f'**Fault Current:** {i_f} A')
+    st.write(f'**Trip Time:** {round(fault_time, 3)} sec')
+
+    # Plot the relay curve
+    fig, ax = plt.subplots(figsize=(10, 6))
+    ax.plot(x_curr, y_time, label="Relay Curve", color='blue')
+
+    # Mark the fault current and trip time on the graph
+    ax.axvline(x=i_f, color='red', linestyle='--', label=f"Fault Current: {i_f} A")
+    ax.axhline(y=fault_time, color='green', linestyle='--', label=f"Trip Time: {round(fault_time, 3)} sec")
+
+    # Adding labels and title
+    ax.set_xlabel('Current (Amp)')
+    ax.set_ylabel('Time (sec)')
+    ax.set_title(f"Relay Curve: {curve}")
+
+    # Adding a legend
+    ax.legend()
+
+    # Show the plot
+    st.pyplot(fig)
+
+# Streamlit app layout
+st.title("Relay Curve Calculator")
+st.sidebar.header("Input Parameters")
+
+# Input fields
+tr_kva = st.sidebar.number_input("Transformer Rating (kVA)", min_value=1.0, value=1000.0, step=1.0)
+tr_volt = st.sidebar.number_input("Transformer Voltage (V)", min_value=1.0, value=11000.0, step=1.0)
+ct_pr = st.sidebar.number_input("CT Primary (Amp)", min_value=1.0, value=200.0, step=1.0)
+ct_sec = st.sidebar.number_input("CT Secondary (Amp)", min_value=1.0, value=5.0, step=1.0)
+fac = st.sidebar.number_input("Fault Anticipation Factor", min_value=1.0, value=1.2, step=0.1)
+tms = st.sidebar.number_input("Time Multiplier Setting (TMS)", min_value=0.01, value=0.1, step=0.01)
+i_f_fac = st.sidebar.number_input("Fault Current Multiplier", min_value=1.0, value=10.0, step=0.1)
+curve = st.sidebar.selectbox("Relay Curve Type", ['IEC Normal Inverse', 'IEC Very Inverse', 'IEC Extremely Inverse', 'IEC Long Time Inverse'])
+
+# Run the calculation when the button is clicked
+if st.sidebar.button("Calculate"):
+    calculate_relay_curve(tr_kva, tr_volt, ct_pr, ct_sec, fac, tms, i_f_fac, curve)