Apparatus and methods for supplying DC power to control circuitry of a matrix converter

Patent metadata

Field	Value
Publication number	US-11848619-B2
Application number	US-202217885436-A
Country	US
Kind code	B2
Filing date	Aug 10, 2022
Priority date	Jan 21, 2020
Publication date	Dec 19, 2023
Grant date	Dec 19, 2023

Abstract

Apparatus and methods for supplying DC power to control circuitry of a matrix converter is provided. In certain embodiments, a matrix converter includes an array of switches having AC inputs for receiving a multi-phase AC input voltage and AC outputs for providing a multi-phase AC output voltage to a load, such as an electric motor. The matrix converter further includes control circuitry for opening or closing individual switches of the array, and a clamp circuit connected between the AC inputs and AC outputs of the array and operable to dissipate energy of the load in response to an overvoltage condition, such as an overvoltage condition arising during shutdown. The clamp circuit includes a switched mode power supply operable to generate a DC supply voltage for the control circuitry.

First claim

What is claimed is:

1. An embedded motor drive including direct AC-AC matrix converter, the embedded motor drive comprising:
a motor drive housing configured to mount to a motor frame of an electric motor;
an electronics module comprising:
a switch array having a plurality of AC inputs configured to receive a multi-phase AC input voltage and a plurality of AC outputs configured to output a multi-phase AC output voltage, the switch array comprising a plurality of bidirectional switches, plurality of AC inputs connected through the switch array to the plurality of AC outputs without an intermediate DC stage;
a plurality of driver circuits each configured to control a respective one of the plurality of bidirectional switches;
a control circuit configured to provide a plurality of input signals to the plurality of driver circuits; and
a clamp circuit electrically connected at an input of the clamp circuit to the plurality of AC inputs and at an output of the clamp circuit to the plurality of AC outputs such that the clamp circuit is externally connected to AC nodes of the switch array, the clamp circuit comprising a switched mode power supply attached to a discharge node of the clamp circuit, the discharge node in a direct discharge current path, the switched mode power supply operable to generate a DC supply voltage for the control circuit, wherein the switched mode power supply is operable over a voltage range of at least 250 V DC, wherein the electronics module is dimensioned to fit within the motor drive housing.

2. The direct AC-AC matrix converter of claim 1 , wherein the clamp circuit further comprises an input diode array connected to the plurality of AC inputs, and an output diode array connected to the plurality of AC outputs.

3. The direct AC-AC matrix converter of claim 1 , further comprising a plurality of isolated DC-to-DC converters each configured to receive the DC supply voltage and to generate a converted DC voltage for a respective one of the plurality of driver circuits.

4. The direct AC-AC matrix converter of claim 1 , wherein the clamp circuit comprises a clamp resistor in series with a discharge device configured to discharge current in response to detection of an overvoltage condition.

5. The direct AC-AC matrix converter of claim 4 , wherein discharge current flows through a discharge path that does not include any capacitors.

6. The direct AC-AC matrix converter of claim 4 , wherein the clamp circuit further comprises a diode electrically connected in parallel with the clamp resistor.

7. A motor drive assembly including a motor drive circuit of an electric motor, comprising:
a motor drive housing configured to mount to a motor frame of an electric motor;
a motor drive circuit comprising:
a plurality of AC inputs;
a plurality of AC outputs;
a direct AC-AC matrix converter comprising:
an array of switches connected to the plurality of AC inputs and configured to receive a multi-phase AC input voltage from the plurality of AC inputs, and the array of switches configured to output a multi-phase AC output voltage at the plurality of AC outputs, the plurality of AC inputs connected through the array of switches to the plurality of AC outputs without an intermediate DC stage;
control circuitry configured to control the array of switches to synthesize the multi-phase AC output voltage from the multi-phase AC input voltage; and
a clamp circuit electrically connected at an input of the clamp circuit to the plurality of AC inputs and at an output of the clamp circuit to the plurality of AC outputs such that the clamp circuit is externally connected to AC nodes of the array of switches, the clamp circuit including a switched mode power supply attached to a discharge node of the clamp circuit, the discharge node in a direct discharge current path, the switched mode power supply operable to generate a DC supply voltage for the control circuitry, wherein the switched mode power supply is operable over a voltage range of at least 250 V DC, wherein the motor drive circuit is dimensioned to fit within the motor drive housing.

8. The motor drive circuit of claim 7 , wherein the clamp circuit comprises a clamp resistor in series with a discharge device configured to discharge current in response to detection of an overvoltage condition.

9. The motor drive circuit of claim 8 , wherein discharge current flows through a discharge path that does not include any capacitors.

10. The motor drive circuit of claim 8 , wherein the clamp circuit further comprises a diode electrically connected in parallel with the clamp resistor.

11. The motor drive circuit of claim 7 , wherein the control circuitry comprises a digital processing circuit that is powered by the DC supply voltage.

12. The motor drive circuit of claim 7 , wherein the array of switches comprises a plurality of bidirectional switches electrically connected between the plurality of AC inputs and the plurality of AC outputs, the direct AC-AC matrix converter further comprising a plurality of driver circuits each configured to control a respective one of the plurality of bidirectional switches.

13. The motor drive circuit of claim 12 , wherein the control circuitry comprises a digital processing circuit that is powered by the DC supply voltage and operable to provide a plurality of input signals to the plurality of driver circuits.

14. The motor drive circuit of claim 13 , further comprising a plurality of isolated DC-to-DC converters each configured to receive the DC supply voltage, the plurality of isolated DC-to-DC converters each configured to generate a converted DC voltage for a respective one of the plurality of driver circuits.

15. A motor assembly including the motor drive assembly of claim 7 , wherein the motor drive housing is supported by a motor frame of the motor assembly.

16. The motor assembly of claim 15 wherein the motor drive housing is removably mountable to the motor frame.

17. A method of supplying DC power in a direct AC-AC matrix converter, the method comprising:
controlling an array of switches using control circuitry to synthesize a multi-phase AC output voltage from a multi-phase AC input voltage, the array of switches including a plurality of AC inputs configured to receive the multi-phase AC input voltage and a plurality of AC outputs configured to output the multi-phase AC output voltage, the plurality of AC inputs connected through the array of switches to the plurality of AC outputs without an intermediate DC stage;
activating a clamp circuit connected at an input of the clamp circuit to the plurality of AC inputs of the array of switches and to the plurality of AC outputs of the array of switches such that the clamp circuit is externally connected to AC nodes of the array of switches; and
generating a DC supply voltage for the control circuitry using a switched mode power supply of the clamp circuit, the switched mode power supply attached to a discharge node of the clamp circuit, the discharge node in a direct discharge current path, wherein the switched mode power supply is operable over a voltage range of at least 250 V DC, wherein the direct AC-AC matrix converter is contained within a motor drive mounted to a motor frame of an electric motor.

18. The method of claim 17 , wherein activating the clamp circuit further comprises turning on a discharge device in response to detecting an overvoltage condition.

19. The method of claim 18 , further comprising selectively turning on the discharge device based on detecting the overvoltage condition

Assignees

• Itt Mfg Enterprises Llc

Inventors

• Williams Dean P

Classifications

• H02M5/297 Primary

  for conversion of frequency · CPC title

• H02M1/32

  Means for protecting converters other than automatic disconnection · CPC title

• H02M5/2932

  with automatic control of output voltage, current or power · CPC title

• H02M5/271 Primary

  from a three phase input voltage · CPC title

• H02M1/34

  Snubber circuits · CPC title