Variable Speed Generator Market Size and Forecasts (2020 - 2030), Global and Regional Share, Trends, and Growth Opportunity Analysis Report Coverage:by Type (Doubly-fed Induction Generator, Permanent Magnet Synchronous Generator, Wound Rotor Induction Generator, Variable Speed Self Excited Induction Generator); Prime Mover (Internal Combustion Engines, Wind Turbines, Hydro Turbines, Steam and Gas Turbines); End User (Marine and Shipbuilding, Power Generation, Oil and Gas, Commercial and Residential, Others) , and Geography (North America, Europe, Asia Pacific, and South and Central America)