Abstract: A multi-stage dynamic braking resistor network (23) is provided that includes a plurality of dynamic brake resistors (1a–d) for dissipating, as heat, regenerative energy inputted onto a system bus (17) by a motor or actuator (19), and a plurality of switches (31a–d) for connecting the dynamic brake resistors (1a–d) to and from the system bus (17), respectively. The multi-stage dynamic braking resistor network (23) further includes a control circuit (25) for controlling the switches (31a–d) such that the dynamic brake resistors (1a–d) are connected to and from the system bus (17) on the basis of a predetermined voltage threshold of the system bus and on the basis of a predetermined rotation pattern.

Abstract: A multi-stage dynamic braking resistor network (23) is provided that includes a plurality of dynamic brake resistors (1a-d) for dissipating, as heat, regenerative energy inputted onto a system bus (17) by a motor or actuator (19), and a plurality of switches (31a-d) for connecting the dynamic brake resistors (1a-d) to and from the system bus (17), respectively. The multi-stage dynamic braking resistor network (23) further includes a control circuit (25) for controlling the switches (31a-d) such that the dynamic brake resistors (1a-d) are connected to and from the system bus (17) on the basis of a predetermined voltage threshold of the system bus and on the basis of a predetermined rotation pattern.

Abstract: An active filter (300) generates multi-phase compensating current in an AC power supply system (10) that supplies a load (200). The filter (300) includes a compensating current output device (34) outputting multi-phase compensating current to an AC power line (50); and a controller (310) for controlling the compensating current output (340) such that the multi-phase compensating current compensates for current harmonics and power factor on said AC power line (50). The controller (310) estimates current harmonics and power factor compensating values as a function of multi-phase power measurements.

Abstract: An active filter (300) generates multi-phase compensating current in an AC power supply system (10) that supplies a load (200). The filter (300) includes a compensating current output device (34) outputting multi-phase compensating current to an AC power line (50); and a controller (310) for controlling the compensating current output (340) such that the multi-phase compensating current compensates for current harmonics and power factor on said AC power line (50). The controller (310) estimates current harmonics and power factor compensating values as a function of multi-phase power measurements.

Abstract: An active filter (100) suppresses current harmonics generated in a dc bus (300) by generating a compensating current that is approximately equal-but-opposite in polarity to the current harmonics. In one implementation, the active filter (100) includes: an energy storage capacitor (103); a choke (104); a switch circuit (120); and a controller (150). The controller (150) receives a current harmonics measurement for the dc bus (300) and generates switch gating signals (156a, 156b) as a function of the current harmonics measurement. The switch circuit (120) receives the switch gating signals (156a, 156b) from the controller (150) and is operatively connected to the energy storage capacitor (103) and the choke (104) to selectively discharge the energy storage capacitor (103) to inject current into the dc bus (300) and to selectively draw current from the dc bus (300) via the choke (104).

Abstract: An active filter (100) suppresses current harmonics generated in a dc bus (300) by generating a compensating current that is approximately equal-but-opposite in polarity to the current harmonics. In one implementation, the active filter (100) includes: an energy storage capacitor (103); a choke (104); a switch circuit (120); and a controller (150). The controller (150) receives a current harmonics measurement for the dc bus (300) and generates switch gating signals (156a, 156b) as a function of the current harmonics measurement. The switch circuit (120) receives the switch gating signals (156a, 156b) from the controller (150) and is operatively connected to the energy storage capacitor (103) and the choke (104) to selectively discharge the energy storage capacitor (103) to inject current into the dc bus (300) and to selectively draw current from the dc bus (300) via the choke (104).