Switch actuation measurement circuit for voltage converter

• US 10,320,322 B2
• Filed: 04/13/2017
• Issued: 06/11/2019
• Est. Priority Date: 04/15/2016
• Status: Active Grant

• Current Assignee: Copeland Corporation LLC (Emerson Electric Company)
• Original Assignee: Emerson Climate Technologies Incorporated (Emerson Electric Company)
• Inventors: Marcinkiewicz, Joseph G., Green, Charles E.
• Primary Examiner(s): Dhakal, Bickey
• Assistant Examiner(s): Truneh, Zemenay T
• Application Number:
  US15/487,101
• Publication Number:
  US 20170302214A1
• Time in Patent Office: 789 Days
• Field of Search: None
• CPC Class Codes: F04B 13/00 Pumps specially modified to deliver fixed or variable measured quantities
• CPC Class Codes: F04B 17/03 driven by electric motors
• CPC Class Codes: F04B 35/04 the means being electric
• CPC Class Codes: F04B 49/06 Control using electricity regulating by means of floats actuating electric switches F04B49/04
• CPC Class Codes: F04B 49/10 Other safety measures
• CPC Class Codes: F04B 49/20 by changing the driving speed
• CPC Class Codes: F04C 18/0215 where only one member is moving
• CPC Class Codes: F04C 2240/40 Electric motor
• CPC Class Codes: F04C 28/28 Safety arrangements; Monitoring
• CPC Class Codes: F04C 29/0085 Prime movers
• CPC Class Codes: F25B 2600/021 Inverters therefor
• CPC Class Codes: F25B 2700/21152 at the discharge side of the compressor
• CPC Class Codes: F25B 31/02 of motor-compressor units
• CPC Class Codes: F25B 49/025 Motor control arrangements
• CPC Class Codes: H02M 1/34 Snubber circuits
• CPC Class Codes: H02M 1/344 Active dissipative snubbers
• CPC Class Codes: H02M 1/346 Passive non-dissipative snubbers
• CPC Class Codes: H02M 1/348 Passive dissipative snubbers
• CPC Class Codes: H02M 1/42 Circuits or arrangements for compensating for or adjusting power factor in converters or inverters
• CPC Class Codes: H02M 1/4208 Arrangements for improving power factor of AC input
• CPC Class Codes: H02M 1/4225 : using a non-isolated boost converter
• CPC Class Codes: H02M 1/44 : Circuits or arrangements for compensating for electromagnetic interference in converters or inverters
• CPC Class Codes: H02P 23/26 : Power factor control [PFC]
• CPC Class Codes: H02P 27/06 : using dc to ac converters or inverters H02P27/05 takes precedence
• CPC Class Codes: H02P 27/08 : with pulse width modulation
• CPC Class Codes: H03K 17/18 : Modifications for indicating state of switch
• CPC Class Codes: H03K 2217/0027 : Measuring means of, e.g. currents through or voltages across the switch
• CPC Class Codes: Y02B 30/70 : Efficient control or regulation technologies, e.g. for control of refrigerant flow, motor or heating
• CPC Class Codes: Y02B 70/10 : Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes

Abstract

A drive includes an inverter power circuit that applies power to an electric motor of a compressor from a direct current (DC) voltage bus. A power factor correction (PFC) circuit outputs power to the DC voltage bus based on input alternating current (AC) power. The PFC circuit includes: (i) a switch having a first terminal, a second terminal, and a control terminal; (ii) a driver that switches the switch between open and closed states based on a control signal; (iii) an inductor that charges and discharges based on switching of the switch; and (iv) a circuit that outputs a signal indicating whether the switch is in the open state or the closed state based on a voltage across the first and second terminals of the switch.

Claims

1. A drive, comprising:

an inverter power circuit that applies power to an electric motor of a compressor from a direct current (DC) voltage bus;

a power factor correction (PFC) circuit that outputs power to the DC voltage bus based on input alternating current (AC) power, the PFC circuit including;

(i) a switch having a first terminal, a second terminal, and a control terminal;

(ii) a driver that switches the switch between open and closed states based on a control signal;

(iii) an inductor that charges and discharges based on switching of the switch;

(iv) a circuit that outputs a signal indicating whether the switch is in the open state or the closed state based on a voltage across the first and second terminals of the switch;

(v) a node that is connected to a first voltage at the first terminal of the switch when the switch is in the closed state and that is connected to a second voltage when the switch is in the open state;

(vi) a first voltage divider that generates a third voltage based on a fourth voltage at the node;

(vii) a second voltage divider that generates a fifth voltage based on a sixth voltage at the second terminal of the switch; and

(viii) a comparator that generates the signal indicating whether the switch is in the open state or the closed state based on a comparison of the third voltage and the fifth voltage.

2. The drive of claim 1 further comprising a control module that generates the control signal based on the signal indicating whether the switch is in the open state or the closed state.

3. The drive of claim 2 wherein the control module measures a period between:

(i) a first time when the control signal transitions from a first state for transitioning the switch one of;

(a) from the open state to the closed state; and

(b) from the closed state to the open state; and

(i) a second time, after the first time, when the signal transitions from a first state to a second indicating that the one of;

(a) the switch transitioned from the open state to the closed state; and

(b) the switch transitioned from the closed state to the open state,

wherein the control module generates the control signal based on the period.

4. The drive of claim 1 wherein the circuit generates the signal indicating that the switch is in the closed state when the voltage across the first and second terminals of the switch is less than a predetermined voltage.

5. The drive of claim 1 wherein the circuit generates the signal indicating that the switch is in the open state when the voltage across the first and second terminals is greater than a predetermined voltage.

6. The drive of claim 1 wherein the second terminal of the switch is connected to a ground potential.

7. The drive of claim 1 wherein the comparator generates the signal indicating that the switch is in the open state when the third voltage is greater than the fifth voltage.

8. The drive of claim 1 wherein the comparator generates the signal indicating that the switch is in the closed state when the third voltage is less than the fifth voltage.

9. A method, comprising:

applying power to an electric motor of a compressor from a direct current (DC) voltage bus;

by a power factor correction (PFC) circuit, providing power to the DC voltage bus based on input alternating current (AC) power, the providing power to the DC bus voltage including switching a switch of the PFC circuit between open and closed states based on a control signal,

wherein the switch includes a first terminal, a second terminal, and a control terminal;

outputting a signal indicating whether the switch is in the open state or the closed state based on a voltage across the first and second terminals of the switch;

connecting a node to a first voltage at the first terminal of the switch when the switch is in the closed state;

connecting the node to a second voltage when the switch is in the open state;

by a first voltage divider, generating a third voltage based on a fourth voltage at the node; and

by a second voltage divider, generating a fifth voltage based on a sixth voltage at the second terminal of the switch,

wherein outputting the signal indicating whether the switch is in the open state or the closed state includes outputting the signal indicating whether the switch is in the open state or the closed state based on a comparison of the third voltage and the fifth voltage.

10. The method of claim 9 further comprising generating the control signal based on the signal indicating whether the switch is in the open state or the closed state.

11. The method of claim 10 further comprising measuring a period between:

(i) a first time when the control signal transitions from a first state for transitioning the switch one of;

(a) from the open state to the closed state; and

(b) from the closed state to the open state; and

(i) a second time, after the first time, when the signal transitions from a first state to a second indicating that the one of;

(a) the switch transitioned from the open state to the closed state; and

(b) the switch transitioned from the closed state to the open state,

wherein generating the control signal includes generating the control signal based on the period.

12. The method of claim 9 wherein outputting the signal indicating whether the switch is in the open state or the closed state includes generating the signal indicating that the switch is in the closed state when the voltage across the first and second terminals of the switch is less than a predetermined voltage.

13. The method of claim 9 wherein outputting the signal indicating whether the switch is in the open state or the closed state includes generating the signal indicating that the switch is in the open state when the voltage across the first and second terminals is greater than a predetermined voltage.

14. The method of claim 9 wherein the second terminal of the switch is connected to a ground potential.

15. The method of claim 9 wherein outputting the signal indicating whether the switch is in the open state or the closed state includes generating the signal indicating that the switch is in the open state when the third voltage is greater than the fifth voltage.

16. The method of claim 9 wherein outputting the signal indicating whether the switch is in the open state or the closed state includes generating the signal indicating that the switch is in the closed state when the third voltage is less than the fifth voltage.