Parallel interleaved 2-level or 3-level regenerative drives

Patent metadata

Field	Value
Publication number	US-9906183-B1
Application number	US-201715419670-A
Country	US
Kind code	B1
Filing date	Jan 30, 2017
Priority date	Jan 30, 2017
Publication date	Feb 27, 2018
Grant date	Feb 27, 2018

Abstract

A paralleled drive having a first plurality of interphase inductors to distribute three phase alternating current power to a first and a second converter that transfer power to a first and a second direct current (DC) buses respectively, a bus coupler connecting the first and second DC buses, a first and a second inverter connected to the first and second DC buses respectively. The drive also includes a controller connected to the first and second converters and the first and second inverters, the controller generates control signals to cause the first and second converter to transfer power to the first and second direct current (DC) buses respectively, and the controller configured to generate control signals to cause the first and the second inverters to generate a plurality of motor excitation signals respectively, and a second plurality of interphase inductors operable to combine the plurality of motor excitation signals.

First claim

The invention claimed is:

1. A three-phase paralleled active front-end drive, comprising:
a first plurality of interphase inductors configured for connection to a three phase alternating current (AC) power source and operable to distribute power from a three phase alternating current source to a first converter and a second converter configured to transfer power to a first and an second direct current (DC) bus respectively;
a bus coupler operably coupling the first DC bus to a second DC bus;
a first inverter operably connected to the first DC bus;
a second inverter operably connected the second DC bus, the first inverter and second the inverter each configured to provide a plurality of motor excitation signals;
a first controller operably connected to the first converter and the second converter as well as the first inverter and the second inverter, the first controller configured to generate control signals to cause the first converter and the second converter to transfer power to a first and an second direct current (DC) bus respectively, and the first controller configured to generate control signals to cause the first inverter and the second inverter to generate a plurality of motor excitation signals respectively; and
a second plurality of interphase inductors operable to combine the plurality of motor excitation signals from the first inverter with the plurality of motor excitation signals from the second inverter.

2. The three-phase paralleled active front-end drive of claim 1 , further comprising a second controller wherein the first controller and the second controller implement a method to cause the first inverter and the second inverter to provide substantially equal motor excitation currents respectively.

3. The three-phase paralleled active front-end drive of claim 2 , wherein:
the first controller generates a first pulse width modulation (PWM) reference signal and the second controller generates a second PWM reference signal;
the first controller and the second controller each generate a duty cycle for the control signals based on the first PWM reference signal and second PWM reference signals respectively,
the first controller generates a first set of control signals to the first inverter and the second controller generates a second set of control signals to the second inverter based on the first PWM reference signal and second PWM reference signals respectively.

4. The three-phase paralleled active front-end drive of claim 3 , further including the first controller communicating timing of a reference point on the first reference to the second controller, the second controller adjusting a period of its PWM reference signal based on the timing.

5. The three-phase paralleled active front-end drive of claim 4 , further including at least one of the first controller and the second controller perturbating a duty cycle of at least one of the first set of control signals and the second set of control signals based on at least one of the first PWM reference signal and second PWM reference signals.

6. The three-phase paralleled active front-end drive of claim 3 , wherein the second PWM reference signal is 180 degrees out of phase from the first pulse width modulation (PWM) reference signal.

7. The three-phase paralleled active front-end drive of claim 1 , wherein the first inverter and the second inverter comprise at least six switching devices.

8. The three-phase paralleled active front-end drive of claim 1 , wherein each interphase inductor includes a pair of windings and is configured to control a circulation current of the three-phase paralleled active front-end drive.

9. The three-phase paralleled active front-end drive of claim 1 , wherein the first controller is configured to implement a method to cause the first inverter and the second inverter to provide substantially equal motor excitation currents respectively.

10. The three-phase paralleled active front-end drive of claim 9 , wherein
the first controller generates a first pulse width modulation (PWM) reference signal and a second PWM reference signal;
the first controller generates a first set of control signals to the first inverter and a second set of control signals to the second inverter based on the first PWM reference signal and second PWM reference signals respectively.

11. The three-phase paralleled active front-end drive of claim 10 , further including perturbating a duty cycle of at least one of the first set of control signals and the second set of control signals based on at least one of the first PWM reference signal and second PWM reference signals.

12. The three-phase paralleled active front-end drive of claim 1 , wherein the first converter includes a two level, three phase converter, the first inverter includes a two level, three phase inverter, the second converter includes a two level, three phase converter, and the second inverter includes a two level, three phase inverter.

13. The three-phase paralleled active front-end drive of claim 1 , wherein at least one of the first converter, the first inverter, the second converter and the second inverter is a three level converter or inverter respectively.

14. The three-phase paralleled active front-end drive of claim 13 , wherein the first converter includes a first converter neutral point, the first inverter includes a first inverter neutral point, the second converter includes a second converter neutral point, the second inverter includes a second inverter neutral point, the first converter neutral point electrically connected to the first inverter neutral point and the second converter neutral point electrically connected to the second inverter neutral point, wherein the first converter neutral point is not electrically connected to the second inverter neutral point and the first inverter neutral point is not electrically connected to the second converter neutral point.

15. The three-phase paralleled active front-end drive of claim 13 , wherein the first converter includes a first converter neutral point, the first inverter includes a first inverter neutral point, the second converter includes a second converter neutral point, the second inverter includes a second inverter neutral point, wherein at least one of (i) the first converter neutral point is electrically connected to the second inverter neutral point and (ii) the first inverter neutral point is electrically connected to the second converter neutral point.

16. The three-phase paralleled active front-end drive of claim 13 , further comprising at least one of a neutral point link electrically connecting the first converter neutral point to the first inverter neutral point and a second neutral point link electrically connecting the second converter neutral point to the second inverter neutral point.

17. A motor control system with a three-phase paralleled active front-end drive, comprising:
a first plurality of interphase inductors configured for connection to a three phase alternating current (AC) power source and operable to distribute power from a three phase alternating current source to a plurality of active converters configured to transfer power to a first and an second direct current (DC) bus respectively;
a bus coupler operably coupling the first DC bus to a second DC bus;
a first inverter operably connected to the first DC bus;
a second inverter operably connected the second DC bus, the first inverter and second the inverter each configured to provide a plurality of motor excitation signals;
a first controller operably connected to the first inverter and the second inverte

Assignees

• Otis Elevator Co

Inventors

• Agirman Ismail

Classifications

• H02M5/4585

  having a rectifier with controlled elements · CPC title

• H02M7/487

  Neutral point clamped inverters · CPC title

• B66B11/043

  actuated by rotating motor; Details, e.g. ventilation (roping on drum, sheave, winch or pulley B66B11/0065; power supply or control B66B1/28, H02P; motor construction H02K) · CPC title

• H02P27/08 Primary

  with pulse width modulation · CPC title

• H02M1/123

  Suppression of common mode voltage or current · CPC title