This lesson covers the concept of non linear magneic systems. The lesson also delves into the rate of change of field energy with respect to time and how it helps derive an expression for the generated forces and torque in the non linear magnetic system. It further discusses the concept of co-energy and how it can be used to derive expressions for mechanical work done in mechanical forces. The lesson concludes with an example of a rotational system where the relationship between field energy and co-energy is described in a non-linear manner.
00:11 - Introduction
01:27 - Discussion on how field energy can be written in a vector form using vectors for various excitations
03:57 - Discussion on the expression for field energy and co-energy in a coil with an applied voltage and current
09:20 - Discussion on how to derive the expression for mechanical work done in mechanical forces
15:07 - Explanation of how to derive the expression for force from the field energy
18:35 - Discussion on how to derive the expression for force from the co-energy
31:27 - Example of rotational system and Explanation of how to derive the expression for the generated electromagnetic torque and force for it
44:26 - Discussion on how to verify the relationship between field energy and co-energy
- The field energy can be expressed in terms of the excitation systems present, whether it's a single coil or multiple coils.
- The rate of change of field energy with respect to time helps derive an expression for the generated forces in the electromechanical system.
- The concept of co-energy is useful in deriving expressions for mechanical work done in mechanical forces.
- In a linear system, the force can be evaluated as the rate of change of field while keeping the flux linkage fixed.
- In a non-linear system, the force can be evaluated as the rate of change of co-energy while keeping current constant.