System and method for energy storage and retrieval

A system comprising:

• a stiff DC bus receiving electrical power from at least one power source and comprising a supercapacitor;
• at least one motor configured to impart mechanical force;
• and
• power conditioning circuitry electrically connected between the at least one motor and the stiff DC bus, the power conditioning circuitry conditioning electrical power received from the stiff DC bus to control the angular speed of a rotor of the generator/motor subsystem when imparting mechanical force.

A system comprising:

• a stiff DC bus;
• a primary power source providing electrical power to the stiff DC bus via a respective diode;
• at least one motor configured to impart mechanical force;
• and
• power conditioning circuitry electrically connected between the motor and the stiff DC bus, the power conditioning circuitry conditioning electrical power received from the stiff DC bus to control the angular speed of a rotor of the generator/motor subsystem when imparting mechanical force.

A system comprising:

• a stiff DC bus;
• at least one primary power source providing electrical power to the stiff DC bus via a respective diode;
• at least one backup power source, each of the at least one backup power source electrically connected to the stiff DC bus via a respective diode;
• and
• a control subsystem for controlling the output voltage of each of the at least one backup power source such that current from the backup power source is caused to flow onto the stiff DC bus via its respective diode only when the operating voltage of the stiff DC bus drops below an acceptable operating level thereby to smoothly return the stiff DC bus to at least the acceptable operating level.