Abstract: A pulse width modulation (PWM) interleaving system is provided. The PWM interleaving system includes active harmonic filters (AHFs). The AHFs are disposed in parallel with each other and with a load. The AHFs are electrically coupled to a common coupling point that is electrically interposed between a grid and the load. The AHFs are configured to affect, by PWM, a characteristic of current flowing between the grid and the load. The PWM interleaving system further includes a controller operably coupled to the AHFs and configured to synchronize the PWMs of the AHFs to thereby cancel ripple currents propagating towards the grid.

Abstract: A three-phase motor drive system for operation from a three-phase alternating current (AC) power source. The three-phase motor drive system includes a three-phase hybrid active harmonic filter (AHF) having an input operably connected to the three-phase AC power source, the three-phase hybrid active harmonic filter comprising an active harmonic filter operably connected in parallel with the three-phase AC power source and a three-phase AC reactor disposed in series between the input and an output of the hybrid active harmonic filter. The three-phase motor drive system also includes a three-phase variable frequency motor drive configured to provide excitation signals to a three-phase motor; and a three-phase AC motor operably connected to the three-phase variable frequency motor drive, the three-phase AC motor responsive the excitation signals.

Abstract: A pulse width modulation (PWM) interleaving system is provided. The PWM interleaving system includes active harmonic filters (AHFs). The AHFs are disposed in parallel with each other and with a load. The AHFs are electrically coupled to a common coupling point that is electrically interposed between a grid and the load. The AHFs are configured to affect, by PWM, a characteristic of current flowing between the grid and the load. The PWM interleaving system further includes a controller operably coupled to the AHFs and configured to synchronize the PWMs of the AHFs to thereby cancel ripple currents propagating towards the grid.

Abstract: A pulse width modulation (PWM) based active harmonic filter (AHF) system including a controller configured to adjust a load on the system from a first to a second load, the first load being greater than the second load, wherein the controller is configured to adjust a frequency of the system from a first to a second frequency when the load is equal to the second load, and wherein the second frequency is greater than the first; a first harmonic compensator configured to filter a first order of harmonics of a load when the load is equal to the second load; and a second harmonic compensator configured to filter a second order of harmonics of the load in parallel with the first order of harmonics when the load is equal to the second load and frequency equals the second frequency, the second order of harmonics being greater than the first order.

Abstract: A pulse width modulation (PWM) based active harmonic filter (AHF) system including a controller configured to adjust a load on the system from a first to a second load, the first load being greater than the second load, wherein the controller is configured to adjust a frequency of the system from a first to a second frequency when the load is equal to the second load, and wherein the second frequency is greater than the first; a first harmonic compensator configured to filter a first order of harmonics of a load when the load is equal to the second load; and a second harmonic compensator configured to filter a second order of harmonics of the load in parallel with the first order of harmonics when the load is equal to the second load and frequency equals the second frequency, the second order of harmonics being greater than the first order.

Abstract: A battery powered elevator system in which the battery and power electronics needed to connect the battery to the machine driving the elevator system are mounted in close proximity within the hoistway of the elevator system to minimize power transmission losses.

Abstract: A battery powered elevator system in which the battery and power electronics needed to connect the battery to the machine driving the elevator system are mounted in close proximity within the hoistway of the elevator system to minimize power transmission losses.