Control system of a wind turbine generator

A control system of a wind turbine generator system, comprising:

• a wind turbine, a gearbox, an electric generator and a converter,
• wherein the control system further comprises a supercapacitor energy storage apparatus, wherein the supercapacitor energy storage apparatus comprises a DC-DC converter and a supercapacitor, wherein the converter comprises DC buses, and the supercapacitor is electrically connected to the DC buses via the DC-DC converter,
• wherein the control system further comprises:
• a voltage monitoring module, a controller, and a voltage control module:
• the voltage monitoring module is configured to detect a voltage of the supercapacitor;
• the controller is configured to determine whether the voltage of the supercapacitor is within an allowable operating range or not, and
• the voltage control module is configured to adjust, when the voltage of the supercapacitor is out of the allowable operating range, the voltage of the supercapacitor to be within the allowable operating range,
• wherein the controller is further configured to, when determining that the voltage of the supercapacitor is lower than a lower limit of the voltage range, further determine whether a current wind speed meets a heavy-wind criteria or not;
• and when the current wind speed is determined to meet the heavy-wind criteria the voltage control module is configured to charge the supercapacitor;
• when the controller determines that the voltage of the supercapacitor is higher than an upper limit of the voltage range, the controller is configured to further determine whether the current wind speed meets a light-wind criteria or not, and the voltage control module is configured to discharge the supercapacitor when the current wind speed meets the light-wind criteria.