Method and device for controlling operation of inverter

A device for controlling an operation of an inverter, comprising:

• a first determining unit, configured to determine whether a direct current side voltage of the inverter is greater than an operation voltage setting threshold, wherein a first controlling unit is executed in a case that the direct current side voltage of the inverter is not greater than the operation voltage setting threshold, and a first adjusting unit is executed in a case that the direct current side voltage of the inverter is greater than the operation voltage setting threshold;
• the first controlling unit, configured to control the inverter to operate according to a five level control strategy;
• the first adjusting unit, configured to adjust the direct current side voltage by using a maximum power tracking algorithm;
• a second adjusting unit, configured to adjust linearly a floating capacitor voltage of the inverter based on the adjusted direct current side voltage;
• a second determining unit, configured to determine whether the adjusted floating capacitor voltage is in a preset range, wherein the preset range ranges from a quarter of the operation voltage setting threshold minus a preset threshold to a quarter of the operation voltage setting threshold plus the preset threshold, and wherein the first controlling unit is executed in a case that the adjusted floating capacitor voltage is in the preset range, and a second controlling unit is executed in a case that the adjusted floating capacitor voltage is not in the preset range;
• and
• the second controlling unit, configured to control the inverter to operate according to a seven level control strategy.

An inverter comprising a device for controlling an operation of an inverter, wherein the device for controlling an operation of an inverter comprises:

• a first determining unit, configured to determine whether a direct current side voltage of the inverter is greater than an operation voltage setting threshold, wherein a first controlling unit is executed in a case that the direct current side voltage of the inverter is not greater than the operation voltage setting threshold, and a first adjusting unit is executed in a case that the direct current side voltage of the inverter is greater than the operation voltage setting threshold;
• the first controlling unit, configured to control the inverter to operate according to a five level control strategy;
• the first adjusting unit, configured to adjust the direct current side voltage by using a maximum power tracking algorithm;
• a second adjusting unit, configured to adjust linearly a floating capacitor voltage of the inverter based on the adjusted direct current side voltage;
• a second determining unit, configured to determine whether the adjusted floating capacitor voltage is in a preset range, wherein the preset range ranges from a quarter of the operation voltage setting threshold minus a preset threshold to a quarter of the operation voltage setting threshold plus the preset threshold, and wherein the first controlling unit is executed in a case that the adjusted floating capacitor voltage is in the preset range, and a second controlling unit is executed in a case that the adjusted floating capacitor voltage is not in the preset range;
• and
• the second controlling unit, configured to control the inverter to operate according to a seven level control strategy.