Device and method for controlling inverter based on predetermined time durations and magnitude of the DC link voltage

Patent metadata

Field	Value
Publication number	US-10566911-B2
Application number	US-201916278559-A
Country	US
Kind code	B2
Filing date	Feb 18, 2019
Priority date	Feb 26, 2018
Publication date	Feb 18, 2020
Grant date	Feb 18, 2020

Abstract

A device and method for controlling an inverter is disclosed. The inverter-controlling device in accordance with the present disclosure determines an operation state of a switching element of an initial charging module based on predetermined time durations and a magnitude of a DC link voltage measured at each of time points corresponding to the predetermined time durations.

First claim

What is claimed is:

1. A device for controlling an inverter, wherein the inverter comprising a rectifying module for rectifying an alternate current (AC) power input from a power supply, a direct current (DC) link capacitor for smoothing and storing a voltage rectified by the rectifying module, an inverting module for outputting an AC power of a predetermined voltage and frequency based on a pulse width modulation (PWM) control signal received from an inverter driver, an initial charging module disposed upstream of the DC link capacitor, and a voltage detection module for detecting a DC link voltage charged in the DC link capacitor, wherein the initial charging module includes an initial charging resistor and a first switching element connected in parallel to the initial charging resistor, wherein the device includes:
an inverter driver for applying a PWM signal to each of gates of a plurality of switching elements of the inverting module; and
a controller configured to determine an operation state of the first switching element based on predetermined time durations and a magnitude of the DC link voltage measured at each of time points corresponding to the predetermined time durations,
wherein the controller is further configured to:
determine, as a first voltage, the DC link voltage at a first time point at which the DC link voltage reaches a predetermined level;
determine, as a second voltage, the DC link voltage at a second time point at which a first time duration has elapsed since the first time point;
determine, as a third voltage, the DC link voltage at a third time point at which a second time duration has elapsed since the second time point;
determine an operation state of the first switching element based on the first to third voltages and the first and second time durations;
determine an operation state of the first switching element based on a voltage difference of the DC link voltage generated via on/off switching operations of the first switching element when the DC link voltage has been initially charged up to an amount corresponding to an input voltage;
apply an off signal to the first switching element at a fourth time point at which a first predetermined time duration has elapsed since the third time point;
determine, as a fourth voltage, the DC link voltage at a fifth time point at which a third time duration has elapsed since the fourth time point;
apply an on signal to the first switching element at a sixth time point at which a second predetermined time duration has elapsed since the fifth time point;
determine, as a fifth voltage, the DC link voltage at a seventh time point at which a fourth time duration has elapsed since the sixth time point; and
determine an operation state of the first switching element based on the fourth and fifth voltages and the voltage difference.

2. The device of claim 1 , wherein when the DC link voltage reaches the predetermined level, a contact of the first switching element is engaged via a voltage across the first switching element such that the first switching element is switched to an on state in a duration between the second time point and the third time point.

3. The device of claim 1 , wherein when the DC link voltage reaches the predetermined level, the controller is further configured to apply an on-signal to the first switching element in a duration between the second time point and the third time point.

4. The device of claim 1 , wherein the controller is further configured to determine that the first switching element is in a normal operation state when a following relationship is satisfied:

(

⁢

V
⁢

⁢
2

-

V
⁢

⁢
1

)

×

T
⁢

⁢
2

T
⁢

⁢
1

<

(

V
⁢

⁢
3

-

V
⁢

⁢
2

)

where V 1 indicate the first voltage, V 2 indicates the second voltage, V 3 indicates the third voltage, T 1 indicates the first time duration, and T 2 indicates the second time duration.

5. The device of claim 1 , wherein the controller is further configured to determine that the first switching element is in a normal operation state when a following relationship is satisfied:

(

V
⁢

⁢
3

-

V
⁢

⁢
4

)

>

Δ
⁢

⁢
V
⁢

⁢
and
⁢

⁢

(

V
⁢

⁢
5

-

V
⁢

⁢
4

)

>

Δ
⁢

⁢
V

where V 4 indicates the fourth voltage, V 5 indicates the fifth voltage, and ΔV indicates the voltage difference.

6. A method for controlling an inverter, wherein the inverter compri

Assignees

• Lsis Co Ltd

Inventors

• Lim Deok-Young
• Lee Hu-Jin
• Yang Chun-Suk

Classifications

• H02M5/4585

  having a rectifier with controlled elements · CPC title

• H02M7/062

  Avoiding or suppressing excessive transient voltages or currents · CPC title

• G01R31/327

  Testing of circuit interrupters, switches or circuit-breakers · CPC title

• H02P27/08

  with pulse width modulation · CPC title

• H02M7/5387

  in a bridge configuration · CPC title