Bidirectional asynchronous generator and battery interface circuit

[摘要] ENGLISH ABSTRACT: In some instances additional power is required to support an electrical load onboard an aircraft. A ram air turbine (RAT) generator can be used to supply the necessary power in conjunction with a storage unit such as a battery or supercapacitors. The RAT is driven by the airflow surrounding the sub-sonic aircraft and acts as the main power supply. The storage unit is charged whenthe RAT is supplying excess power or when the load is disconnected.This thesis presents the design and implementation of a prototype circuit that demonstrates the interface between a generator and a battery of electrochemicalcells to an electrical load. To simulate the airflow through the turbine an asynchronous machine is employed to turn the shaft of an asynchronous generator. The prototype circuit is designed such that the battery is connected to a dc bus through a bidirectional dc-dc converter and the asynchronous machine interfaces with the dc bus through a bidirectional inverter.The load is connected between the positive and negative dc bus rails.The dc-dc converter circuit functions to regulate the dc bus voltage by utilising a double control loop strategy with an inner and outer control loop.The inverter functions as a synchronous rectifier and the power delivered to the dc bus from the generator is controlled as a function of the converter's battery voltage. The simulated and measured test results of the complete system are compared and presented.

[发布机构] Stellenbosch University