摘要 |
<p>Power distribution is managed between a regenerative drive (10) connected to an elevator hoist motor (12), and a primary power supply (20) and electrical energy storage (EES) system (36) connected to the regenerative drive. A state-of-charge (SOC) of the EES system and a primary current flow between the primary power supply and the regenerative drive are measured. A direction and magnitude of secondary current flow between the EES system and the regenerative drive is then controlled as a function of the primary current flow and the SOC of the EES system. SOC of the EES system is maintained in a limited range except as necessary to maintain primary current flow below a threshold current.</p> |