Hua Bai

US Patent:

20180278168, Sep 27, 2018

Filed:

Mar 8, 2018

Appl. No.:

15/915400

Inventors:

- Lippstadt, DE
Hua Bai - Flint MI, US

International Classification:

H02M 3/335
H02P 27/06
H02J 7/00
H02J 7/02
H02M 1/08
H02M 1/42

Abstract:

An apparatus includes a controller, a switching block, and a three-phase bidirectional AC/DC converter. The switching block has a first interface connected to a power grid, a second interface connected to an electric motor, and a third interface connected to the three-phase bidirectional AC/DC converter that includes first, second, and third single-phase AC/DC conversion modules, and which have inputs and outputs joined at an output node, and a respective transformer configured to provide electrical isolation. In a first mode of operation, the switching block connects the power grid to the AC/DC converter for charging a battery connected to the output node and disconnects the electric motor. In a second mode of operation, the switching block disconnects the power grid and connects the electric motor to the AC/DC converter which is controlled to convert DC power drawn from the battery to energize the electric motor.

US Patent:

20180054126, Feb 22, 2018

Filed:

Jun 30, 2017

Appl. No.:

15/639509

Inventors:

- Lippstadt, DE
Hua Bai - Flint MI, US

International Classification:

H02M 3/335
H02M 1/42
H02M 1/08
H02M 1/14
H02M 1/00

Abstract:

An AC/DC conversion apparatus includes first, second, and third AC/DC conversion modules operated by a controller in two modes of operation. In the first mode, the input AC signal is 3-phase and each of the three modules are enabled to handle a respective one of the input phases. In the second mode, the input AC signal is single phase and the first and second modules are enabled to deliver output power based on the single-phase AC input, while the controller actuates an H-bridge switches in the third module to which active filter circuitry is connected, to reduce an AC component in the output signal. The active filter circuitry can be selectively connected to the H-bridge switches when single-phase operation is desired, which circuitry may be disposed in a filter housing having male electrical terminals that cooperate with corresponding female terminals associated with the third module.

US Patent:

20180026628, Jan 25, 2018

Filed:

Jun 30, 2017

Appl. No.:

15/639183

Inventors:

- Lippstadt, DE
Hua Bai - Flint MI, US
Hui Teng - Flint MI, US

International Classification:

H03K 17/284
H01L 29/16
H01L 29/778
H01L 29/20
H01L 29/78

Abstract:

A hybrid switch apparatus includes a gate drive circuit producing a gate drive signal, a GaN high electron mobility transistor (HEMT) having a first gate, a first drain, and a first source. A silicon (Si) MOSFET has a second gate, a second drain, and a second source. The GaN HEMT and the Si MOSFET are connected in a parallel arrangement so that (i) the first drain and the second drain are electrically connected and (ii) the first source and the second source are electrically connected. The second gate is connected to the gate drive circuit output to receive the gate drive signal. A delay block has an input connected to the gate drive circuit output and an delay block output is configured to produce a delayed gate drive signal for driving the GaN HEMT.

US Patent:

20160056744, Feb 25, 2016

Filed:

Aug 25, 2014

Appl. No.:

14/467455

Inventors:

Ahmad Arshan Khan - Troy MI, US
Young Joo Lee - Rochester MI, US
Bing Cheng - West Bloomfield MI, US
Hua Bai - Flint MI, US
Fei Yang - Flint MI, US
Allan Taylor - Flint MI, US

International Classification:

H02P 21/14

Abstract:

A system and method for controlling an interior permanent magnet synchronous motor (IPMSM) are presented. In an exemplary implementation, phase current ripple estimation techniques are utilized for variable frequency switching pulse-width modulation control of the IPMSM. In one implementation, the method includes controlling a three-phase inverter based on an initial switching frequency to generate a three-phase alternating current (AC) voltage for the IPMSM. Transformed voltages are determined in a rotating reference frame based on the three-phase AC voltage in the stationary reference frame. Current ripples are determined in the rotating reference frame based on the transformed voltages. Phase current ripples are determined in the stationary reference frame based on the current ripples in the rotating reference frame. A modified switching frequency for the three-phase inverter is determined based on the initial switching frequency and the phase current ripples. The three-phase inverter is then controlled based on the modified switching frequency.

US Patent:

20150019055, Jan 15, 2015

Filed:

Jul 3, 2014

Appl. No.:

14/323563

Inventors:

Zhong Nie - Troy MI, US
Mengyang Zhang - Troy MI, US
Dennis Krozek - Novi MI, US
Fred A. Householder - Shelby Township MI, US
Hua Bai - Flint MI, US
Wei Guo - Novi MI, US
Chen Duan - Northville MI, US

International Classification:

H02M 3/335
B60R 16/03

US Classification:

701 22

Abstract:

Techniques are presented for synchronous rectification control (SRC) of a DC-DC converter in an electrified vehicle (EV) can include determining a required output current for the DC-DC converter based on a secondary voltage of a secondary battery system of the EV, the DC-DC converter being configured to convert a primary voltage from a primary battery system of the EV to the secondary voltage. The techniques can include determining, at the controller, a switching frequency for the DC-DC converter that causes the DC-DC converter to output the required output current. The techniques can include determining turn-on and turn-off delays of the DC-DC converter based on the required output current and the switching frequency using one or more look-up tables. The techniques can also include controlling the DC-DC converter efficiency based on the turn-on and turn-off delays.