US 11,309,789 B2 · Inverter and soft-start method for the same

Abstract

The invention discloses an inverter and a soft-start method for the same. The inverter is electrically connected between a DC power supply and a grid and includes a main power circuit electrically coupled to the grid through a relay, a filter, the relay, and a controller electrically connected with the main power circuit and the relay, respectively. The soft-start method includes: sampling a grid voltage of the grid; calculating an output voltage of the controller, and calculating a virtual current based on the output voltage of the controller, the grid voltage and a virtual impedance; and performing current closed-loop control by taking the virtual current as a feedback signal and sending a relay control signal to turn on the relay when a steady state is reached. The invention enables the soft start of the inverter without increasing any hardware circuit, such as a starting resistor, or the like.

Claims24

Dependent claims

A soft-start method for an inverter electrically connected between a DC power supply and a grid, the inverter comprising a main power circuit, a filter, a relay, and a controller, and the main power circuit electrically coupled to the grid through the relay, and the controller electrically connected with the main power circuit and the relay, respectively, the soft-start method comprising:

sampling a grid voltage of the grid;
calculating an output voltage of the controller, and calculating a virtual current based on the output voltage of the controller, the grid voltage and a virtual impedance;
and
performing current closed-loop control by taking the virtual current as a feedback signal, and sending a relay control signal to turn on the relay upon a steady state being reached.

1 more element

An inverter electrically connected between a DC power supply and a grid, and comprising a main power circuit, a filter, a relay, a controller, and the main power circuit electrically coupled to the grid through the relay, and the controller electrically connected with the main power circuit and the relay, respectively, the controller comprising:

a sampling unit for sampling a grid voltage of the grid;
a virtual current calculating unit for calculating an output voltage of the controller, and calculating a virtual current based on the output voltage of the controller, the grid voltage and a virtual impedance;
and
a current control unit for performing current closed-loop control by taking the virtual current as a feedback signal, and sending a relay control signal to turn on the relay upon a steady state being reached.

1 more element

Dependencies are inferred from the claim text.

Inverter and soft-start method for the same

Life of this patent

Inverter and soft-start method for the same

Life of this patent

Abstract

Claims24