Voltage dynamics of small integrated AC/DC power systems

Switch-mode converters are used in small integrated AC/DC power systems to generate desired AC voltage output with adjustable magnitude and frequency for the purpose of power transfer and load control. We develop a DC link dynamic model for voltage stability analysis of a radial power system. We analyse the converter consisting of an uncontrolled diode rectifier and a voltage controlled voltage source inverter. We show that a single DC link system may exhibit more than two power flow solutions. Stability analysis with the consideration of DC link dynamics is conducted on different branches of power flow solutions for feasible and controllable system operating points. The simulation results obtained from a four-bus test system are given. These studies provide us operable and secure system states of the small integrated AC/DC power systems