Ming Li

US Patent:

20140043871, Feb 13, 2014

Filed:

Aug 7, 2012

Appl. No.:

13/568578

Inventors:

Miaosen Shen - Vernon CT, US
Ming Li - West Hartford CT, US
Lei Xing - East Hartford CT, US

Assignee:

Hamilton Sundstrand Corporation - Windsor Locks CT

International Classification:

H02M 1/12

US Classification:

363 40

Abstract:

A circuit for providing damping in an electromagnetic interference (EMI) filter with an inductor-capacitor (LC) circuit, includes at least one capacitor connected to receive a common-mode current from the LC circuit; a current sensor that senses the common-mode current; a linear amplifier that amplifies the sensed common-mode current; and a power amplifier that receives the amplified sensed common-mode current and outputs a voltage which creates a damping impedance for frequencies of the common-mode current less than a threshold frequency and absorbs the common-mode current for frequencies greater than the threshold frequency.

US Patent:

20140376283, Dec 25, 2014

Filed:

Jun 21, 2013

Appl. No.:

13/923676

Inventors:

- Charlotte NC, US
Ming Li - West Hartford CT, US
Miaosen Shen - Vernon CT, US
Vladimir Blasko - Avon CT, US

International Classification:

H02J 3/24

US Classification:

363 39

Abstract:

Embodiments relate to systems and methods for an active damping device for stabilizing a power grid of active sources and loads. In power system networks or grids which incorporate active power sources and active loads, such as motors, the output voltage transfer function can exhibit instabilities due to the presence of poles in the positive real portion (right hand side) of the complex plane. Those poles can induce uncontrolled ringing, oscillations, or other artifacts or instabilities. According to implementations, an active damping element can be introduced into the power system grid, which operates to drive the poles of the output transfer function to the negative real (left hand) portion of the complex plane. Output voltage and other parameters can thereby be stabilized. In implementations, the damping element can include an R-C network for DC output systems, or a controller including a voltage source inverter for AC output systems.