Electrical power generator with active noise cancellation in ventilation ducts

A method to suppress noise emanating from an electrical power generator, comprising:

• rotating a rotor of the generator at a rotational speed to generate electrical power with a frequency equal to the rotational speed of the rotor;
• in each of a plurality of cells of a ventilation duct of the generator:
• receiving in a microphone sound emanating from the generator, wherein the microphone is at a first place in the cell and near the generator;
• analyzing the received sound and, based on the analysis, generating a destructive sound signal corresponding to the received sound, the analyzing including monitoring the rotational speed of the rotor of the generator and determining a phase and amplitude of the sound emanating from the generator at tonal frequencies corresponding to multiples of the monitored rotational speed of the rotor of the generator;
• and
• broadcasting the destructive sound signal into the cell of the duct, wherein the destructive sound signal destructively interferes with the sound emanating from the generator and propagating through the ventilation duct, the destructive interference reducing a noise level of sound emanating from the cell as compared to a noise level of the sound emanating from the generator;
• determining fluctuations in the rotational speed of the rotor of the generator due to load changes on the generator and changes to a rotational speed of a turbine driving the generator;
• and
• adjusting the destructive sound signal based on the fluctuations in the rotational speed of the rotor of the generator.

A noise suppression system configured for an industrial electrical power generator, the system comprising:

• a microphone and a speaker in each of a plurality of cells of a ventilation duct, the microphone positioned near the generator and configured to receive a sound signal emanating from the generator as a rotor of the generator rotates at a rotational speed to generate electrical power with a frequency equal to the rotational speed of the rotor and passing through the cell;
• a controller configured, for each cell, to analyze the received sound signal and generate a destructive sound signal corresponding to the received sound signal based on the rotational speed of the rotor of the generator, the controller determining a phase and amplitude of the received sound signal at tonal frequencies of the generator corresponding to multiples of the rotational speed of the rotor of the generator;
• wherein, in each cell, the destructive sound signal is broadcast into the cell by the speaker, the destructive sound signal destructively interfering with and reducing a noise level of the sound signal emanating from the generator and passing through the cell;
• the controller further configured to:
• determine fluctuations in the rotational speed of the rotor of the generator due to load changes on the generator and changes to a rotational speed of a turbine driving the generator;
• and
• adjust the destructive sound signal broadcast in each cell based on the fluctuations in the rotational speed of the rotor of the generator.