Bifurcation Analysis of a Van der Pol-Duffing Circuit with Parallel Resistor

Figure 18

Phase portrait of system (1.1) for 𝜇=𝜇_𝑄1, 𝜈=𝜈_𝑄1, and 𝛽=3.973353871<𝛽_𝑄1. The three equilibria are unstable and there exists a “big” stable periodic orbit encircling them. Eigenvalues at 𝐸₀ are 𝜆₁=0.368, 𝜆₂=−1.969, 𝜆₃=−0.337. Eigenvalues at 𝐸_± are 𝜆₁=−2.144, 𝜆_2,3=0.010±0.478𝑖.

(a)

(b)