Power oscillation suppression system and method of grid-connected inverter

Abstract

The present invention belongs to the field of electrical engineering and relates to a power oscillation suppression system and method of a grid-connected inverter. According to the method, a direct-current voltage differential component is fed back to a corresponding control link, and corresponding feedback parameter configuration is performed; and therefore, the suppression of the power oscillation of a grid-connected system can be realized, and the adaptability range and control parameter domain of a power grid can be greatly improved. The power oscillation suppression system of the grid-connected inverter of the invention has the advantages of obvious effects, simple structure, no increase in other external hardware costs, applicability for weak grids in a large range, and strong robustness to control loop parameter disturbances.

Description

technical field [0001] The invention relates to the field of electricity, in particular to a power oscillation suppression system and method for a grid-connected inverter. Background technique [0002] At present, common suppression algorithms for inverter grid-connected system oscillation include: lead-lag compensation method, virtual impedance method, adaptive control, etc. The lead-lag compensation method is to add a lead-lag compensator to the inverter current loop, and design the time constant of the lead-lag to increase the phase angle margin of the closed-loop system, so as to achieve the effect of improving stability and suppressing oscillation. The main problem of this method is that the parameter design is too complicated, the lead-lag calculation will inevitably reduce the control response speed, and it only works for a specific power grid; phase margin to suppress oscillations. The problem with this method is that the parameter design is too complicated, and it...

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Problems solved by technology

The main problem of this method is that the parameter design is too complicated, the lead-lag calculation will inevitably reduce the control response speed, and it only works for a specific power grid; phase margin to suppress oscillation

The problem with this method is that the parameter design is too complicated, and it only works for a specific power grid; adaptive control measures the grid impedance in real time and uses its parameters to generate AC voltage, thereby using AC voltage feedforward to weaken the grid impedance The impact of changes on inverter control, suppressing oscillation problems caused by changes in grid impedance

The problem with this method is that additional current and voltage sensors need to be introduced, which increases the hardware cost of the inverter, and secondly, calculating the impedance will also reduce the control response speed, etc.

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