US 12,506,338 B2 · Systems and methods for controlling a DC/AC inverter for use with an electric motor or an AC grid

Abstract

Systems and methods relating to controlling power from renewable power sources. There is provided a control system that uses a non-linear controller for controlling currents in a DC/AC inverter especially when the DC/AC inverter is providing PV power to a 3-phase motor when the system is in an off-grid mode. In on-grid mode, a power grid is coupled to the DC/AC inverter and the control system provides MPPT to provide PV power to the grid. In off-grid mode, the grid is not coupled to the DC/AC inverter. The non-linear controller is based on differentiable manifolds that are also Lie groups. In off-grid mode, this non-linear controller finds the correct phase and frequency for the inverter current for the motor. The frequency is the output of the Lie group-based controller and is generated based on the voltage and current vectors of the motor.

Claims9

Dependent claims

A system for converting power from at least one renewable power source into power suitable for use by either a 3-phase power grid or a 3 phase electric motor, the system comprising:

at least one DC/DC converter receiving power from said renewable power source and transmitting DC power from said at least one renewable power source to a DC bus;
a three-phase DC/AC inverter receiving DC power from said at least one DC/DC converter by way of said DC bus, said DC/AC inverter converting said DC power from said DC bus into three phase AC power suitable for said power grid or said electric motor;
and
a control subsystem for controlling switches in said DC/AC inverter based on sensed output currents and voltages output from said inverter, said control subsystem determining reference vector fields based on said sensed output currents and voltages from said inverter and on sensed input currents and voltages from said DC bus, said reference vector fields being used by said control subsystem to generate switching signals for said switches in said DC/AC inverter.

1 more element

A control subsystem for controlling switches in an inverter, the subsystem comprising:

a DC/DC control block for controlling at least one DC/DC converter, said DC/DC control block receiving sensed currents and voltages from at least one renewable power source;
a motor identification block for determining characteristics of an electric motor, said motor identification block receiving sensed output currents and voltages from said inverter and a voltage for a DC bus that receives power from said at least one DC/DC converter;
a differential geometric controller receiving outputs of said motor identification block and said DC/DC control block;
and
a modulator block for producing control signals for controlling said switches in said inverter, said modulator block receiving outputs of said differential geometric control block and using said outputs of said differential geometric control block to produce said control signals.

2 more elements

Dependencies are inferred from the claim text.

Systems and methods for controlling a DC/AC inverter for use with an electric motor or an AC grid

Life of this patent

Systems and methods for controlling a DC/AC inverter for use with an electric motor or an AC grid

Life of this patent

Abstract

Claims9