Abstract: A diesel-storage independent microgrid and a virtual dynamic synchronous control method and system are described. An adaptive dynamic synchronous torque and pre-synchronous compensation phase angles are introduced into a energy storage converter control system to realize output voltage and power synchronization before and after parallel connection of the system. By compensating the pre-synchronous phase angles, the phase angles of a diesel generator and an energy storage converter are kept consistent before parallel connection, which reduces current impact during the parallel process. By introducing the adaptive dynamic synchronous torque, after the parallel connection of the system, the virtual torque of the energy storage converter can be adaptively and dynamically adjusted according to the current accelerations of the diesel generator and the energy storage converter under the condition that the inertial parameter of a diesel engine is black-boxed.

Abstract: The present invention discloses a diesel-storage independent microgrid and a virtual dynamic synchronous control method and system therefor. An adaptive dynamic synchronous torque and pre-synchronous compensation phase angles are introduced into the energy storage converter control system to realize output voltage and power synchronization before and after parallel connection of the system. By compensating the pre-synchronous phase angles, the phase angles of a diesel generator and an energy storage converter are kept consistent before parallel connection, which reduces current impact during the parallel process.

Abstract: The present invention discloses an island microgrid system and an interactive oscillation suppression method and system therefor. A source-side virtual synchronous machine and a load-side virtual synchronous machine are combined to provide virtual inertia and damping. The present invention provides a d-axis inductive current feedforward control method and a d-axis voltage feedback control method to remodel impedances of VSGs, so as to reduce impedance amplitudes of the VSGs. Therefore, low-frequency interaction between the VSG and LVSM may be suppressed. The present invention may be used to solve interactive oscillation problems of an alternating-current island microgrid composed of a plurality of source-load virtual synchronous machines.

Abstract: A steady state control method for a three-phase double-mode inverter. Off-grid steady state control is composed of outer loop power droop control, voltage feed-forward quasi-resonant control, and inner current loop dead-beat control. Therefore, the response speed of the inverter is raised, and the influence caused by the load fluctuation of a micro-grid is inhibited. Based on the off-grid steady state control, grid-connected steady state control introduces phase lead control to the power droop control. Therefore, the output voltage of the inverter is always slightly ahead of the power grid voltage, which avoids the energy pour backward phenomenon of the inverter due to a phase error, and realizes stable and reliable running in the grid-connected mode.

Abstract: A steady state control method for a three-phase double-mode inverter. Off-grid steady state control is composed of outer loop power droop control, voltage feed-forward quasi-resonant control, and inner current loop dead-beat control. Therefore, the response speed of the inverter is raised, and the influence caused by the load fluctuation of a micro-grid is inhibited. Based on the off-grid steady state control, grid-connected steady state control introduces phase lead control to the power droop control. Therefore, the output voltage of the inverter is always slightly ahead of the power grid voltage, which avoids the energy pour backward phenomenon of the inverter due to a phase error, and realizes stable and reliable running in the grid-connected mode.