Motor drive apparatus and air conditioner

Patent metadata

Field	Value
Publication number	US-2017279377-A1
Application number	US-201415506357-A
Country	US
Kind code	A1
Filing date	Nov 4, 2014
Priority date	Nov 4, 2014
Publication date	Sep 28, 2017
Grant date	—

Abstract

A motor drive apparatus driving a motor as a three-phase motor converting direct current into three-phase alternating current, includes: inverter modules and equivalent in number to phases of the motor; and a control unit generating PWM signals used to drive the inverter modules with PWM. The inverter modules each include a plurality of switching element pairs connected in parallel, each of the switching element pairs including two switching elements connected in series.

First claim

1 - 12 . (canceled)

13 . A motor drive apparatus driving a motor, comprising:
inverter modules equivalent in number to phases of the motor; and a control unit generating a PWM signal used to drive the inverter modules with PWM, wherein a pulse width of the PWM signal changes according to a current flowing through at least one of the inverter modules, and the inverter modules each include a plurality of switching element pairs connected in parallel, each of the switching element pairs including two switching elements connected in series.

14 . The motor drive apparatus according to claim 13 , further comprising a current measurement unit measuring a current flowing through the switching elements, wherein
a pulse width of the PWM signal changes according to the current measured by the current measurement unit.

15 . The motor drive apparatus according to claim 13 , further comprising:
a drive control unit generating, for each of the inverter modules, an individual PWM signal for each of the switching element pairs in a corresponding one of the inverter modules on a basis of the PWM signal generated by the control unit and adjusting a pulse width of the individual PWM signal by using a current flowing through the inverter modules.

16 . The motor drive apparatus according to claim 14 , wherein the current measurement unit is provided for each of the switching elements.

17 . The motor drive apparatus according to claim 14 , wherein the current measurement unit is provided for each arm.

18 . The motor drive apparatus according to claim 14 , wherein the current measurement unit is a single current measurement unit.

19 . The motor drive apparatus according to claim 17 , wherein the drive control unit obtains a characteristic of each of the switching elements by measuring a current for each of the switching elements while the motor is not operating and adjusts a pulse width of the individual PWM signal by using the current measured by the current measurement unit and the characteristic while the motor is operating.

20 . The motor drive apparatus according to claim 18 , wherein the drive control unit obtains a characteristic of each of the switching elements by measuring a current for each of the switching elements while the motor is not operating and adjusts a pulse width of the individual PWM signal by using the current measured by the current measurement unit and the characteristic while the motor is operating.

21 . The motor drive apparatus according to claim 13 , further comprising a heat dissipation unit including a heat dissipating fin, wherein
the heat dissipation unit includes a protrusion to be connected to the inverter modules equivalent in number to the phases of the motor.

22 . The motor drive apparatus according to claim 13 , further comprising:
a heat dissipation unit including a heat dissipating fin; and an auxiliary member connecting the heat dissipation unit and the inverter modules equivalent in number to the phases of the motor such that the inverter modules are connected at a same height.

23 . The motor drive apparatus according to claim 21 , wherein a passage of a cooling medium used to dissipate heat by the heat dissipating fin is orthogonal to a direction of alignment of the inverter modules.

24 . The motor drive apparatus according to claim 22 , wherein a passage of a cooling medium used to dissipate heat by the heat dissipating fin is orthogonal to a direction of alignment of the inverter modules.

25 . The motor drive apparatus according to claim 13 , wherein the switching elements are made from a wide band-gap semiconductor.

26 . The motor drive apparatus according to claim 25 , wherein the wide band-gap semiconductor is silicon carbide.

27 . An air conditioner comprising:
the motor drive apparatus according to claim 13 ; and a compressor including the motor driven by the motor drive apparatus.

Assignees

• Mitsubishi Electric Corp

Inventors

• Shimomugi Takuya
• Shinomoto Yosuke
• Arisawa Koichi
• Hatakeyama Kazunori

Classifications

• H02M7/53875 Primary

  with analogue control of three-phase output · CPC title

• H02M7/48 Primary

  using discharge tubes with control electrode or semiconductor devices with control electrode · CPC title

• H02M2007/53876

  Electricity · mapped topic

• H02M1/0009

  Devices or circuits for detecting current in a converter · CPC title

• H05K7/2039

  characterised by the heat transfer by conduction from the heat generating element to a dissipating body (arrangements for increasing/decreasing heat-transfer, e.g. fins details, F28F13/00) · CPC title