Initializing virtual oscillator control
AssigneeSunPower Corporation
InventorFernando Rodriguez
Life of this patent
Estimating the term…
Abstract
A first micro-inverter and a second micro-inverter are arranged to source a load. The micro-inverters include a virtual oscillator control (VOC) to provide voltage commands to an hysteretic current regulator. The hysteretic current regulator provides instructions to the DC/AC inverter to output voltage to the load. When the second micro-inverter is powered on, an initialization process is executed to provide values to its VOC that reduces transients and improves the synchronization process with the first micro-inverter.
Claims20
An arrangement of micro-inverters to source a load comprising:
- a first micro-inverter to provide AC power to the load;
- and
- a second micro-inverter to provide AC power to the load, the second micro-inverter including
- a DC/AC inverter to generate the AC power;
- an hysteretic current regulator configured to provide an instruction to the inverter to provide the AC power based on a current command;
- a virtual oscillator control configured to generate a voltage command;
- a voltage regulator configured to convert the voltage command to the current command;
- and
- a delay block coupled between the virtual oscillator control and the voltage regulator, wherein the delay block receives an initial current command from the voltage regulator during a startup mode and, after a cycle, provides the current command to the virtual oscillator control in order to initialize a function of the virtual oscillator control.
A method to initialize a virtual oscillator control in a second micro-inverter connected to a load along with a first micro-inverter, the method comprising:
- receiving a sensed voltage from the first micro-inverter;
- determining a current command from the sensed voltage;
- delaying the current command for a cycle;
- receiving the current command at the virtual oscillator control to initialize a function at the virtual oscillator control;
- and
- generating a voltage command using the function.
A micro-inverter comprising:
- an hysteretic current regulator;
- a virtual oscillator control (VOC) configured to generate a voltage command;
- a voltage regulator configured to convert the voltage command to the current command;
- and
- a delay circuit, the delay circuit configured to receive a current command from the voltage regulator during a startup online cycle and to send the received current command to the VOC after at least a predetermined period of time has passed,
- wherein the startup initialization cycle continues until an output current regulated by the hysteretic current regulator synchronizes with an alternating current being supplied to a load.
Dependencies are inferred from the claim text.