PID controller basics for power electronics - Mini Project: Build & Apply

PID Controller Basics for Power Electronics

📖 Scenario: You are designing a simple PID controller to regulate the output voltage of a power converter. The PID controller adjusts the control signal based on the error between the desired voltage and the actual voltage.

🎯 Goal: Build a step-by-step understanding of how to set up a PID controller by defining the error, setting PID gains, calculating the control signal, and applying the control signal limits.

📋 What You'll Learn

Define the error as the difference between the reference voltage and the measured voltage

Set the PID gains: proportional (Kp), integral (Ki), and derivative (Kd)

Calculate the control signal using the PID formula with error, integral of error, and derivative of error

Apply saturation limits to the control signal to keep it within allowed bounds

💡 Why This Matters

🌍 Real World

PID controllers are widely used in power electronics to regulate voltages and currents precisely, ensuring stable and efficient operation of converters and inverters.

💼 Career

Understanding PID basics is essential for engineers working in power electronics design, control systems, and automation to develop reliable and optimized control solutions.

1

Define the error variable

Create two variables: V_ref with value 12.0 (volts) and V_meas with value 10.5 (volts). Then create a variable called error that is the difference between V_ref and V_meas.

Power Electronics

# Define reference and measured voltages
# Your code here

Need a hint?

Subtract the measured voltage from the reference voltage to get the error.

2

Set PID gain constants

Create three variables called Kp, Ki, and Kd and set them to 1.2, 0.01, and 0.05 respectively.

Power Electronics

V_ref = 12.0
V_meas = 10.5
error = V_ref - V_meas
# Set PID gains
# Your code here

Need a hint?

Assign the exact values to each gain variable.

3

Calculate the PID control signal

Create variables integral_error and derivative_error with values 0.2 and -0.1 respectively. Then calculate the control signal u using the formula: u = Kp * error + Ki * integral_error + Kd * derivative_error.

Power Electronics

V_ref = 12.0
V_meas = 10.5
error = V_ref - V_meas
Kp = 1.2
Ki = 0.01
Kd = 0.05
# Define integral and derivative errors
# Your code here

Need a hint?

Use the PID formula combining proportional, integral, and derivative terms.

4

Apply saturation limits to the control signal

Create variables u_min and u_max with values 0 and 15 respectively. Then update u so it is limited between u_min and u_max using conditional statements.

Power Electronics

V_ref = 12.0
V_meas = 10.5
error = V_ref - V_meas
Kp = 1.2
Ki = 0.01
Kd = 0.05
integral_error = 0.2
derivative_error = -0.1
u = Kp * error + Ki * integral_error + Kd * derivative_error
# Define saturation limits and apply them to u
# Your code here

Need a hint?

Use if-elif statements to keep u within the limits.