| 摘要 |
<p>A bi-directional converter (i.e., AC- > DC or DC- > AC) for transferring electrical energy between a high voltage AC power grid (12) and a DC energy storage/supply (22) (such as a battery or a series of photovoltaic or fuel cells). The converter includes a PWM inverter (20) coupled to the grid (12), and a DC-DC chopper (21) coupled between the PWM inverter (20) and a DC energy storage/supply (22). The PWM inverter (20) includes a switching circuit (26) having high speed electrical switches arranged in pairs coupled between the AC grid phase voltage rails and DC-DC chopper voltage rails. An inverter control unit (24) includes a DC bus voltage regulator (40) to regulate the voltage on the DC side of the PWM inverter (20), and a reactive power controller (42). A DC control unit (23) includes a real power controller (41) that controls the real power flow by controlling the current flow of the DC energy storage/supply (22). By modulating the DC switches (25) in the DC-DC chopper (21), the DC current to the DC energy storage/supply (22) is controlled to provide a desired real power flow through the DC-DC chopper (21), independent of the voltage (VDC) of the energy storage/supply (22).</p> |
