US 12,438,477 B2
Protection control unit for an inverter controlling current flow to a head capacitor
Kyohei Watanabe, Tokyo (JP); and Takayuki Takashige, Tokyo (JP)
Assigned to MITSUBISHI HEAVY INDUSTRIES THERMAL SYSTEMS, LTD., Tokyo (JP)
Appl. No. 17/437,657
Filed by MITSUBISHI HEAVY INDUSTRIES THERMAL SYSTEMS, LTD., Tokyo (JP)
PCT Filed Mar. 11, 2020, PCT No. PCT/JP2020/010436
§ 371(c)(1), (2) Date Sep. 9, 2021,
PCT Pub. No. WO2020/184598, PCT Pub. Date Sep. 17, 2020.
Claims priority of application No. 2019-047681 (JP), filed on Mar. 14, 2019.
Prior Publication US 2022/0166345 A1, May 26, 2022
Int. Cl. H02M 7/5387 (2007.01); F04D 27/00 (2006.01); H02M 1/32 (2007.01); H02P 27/06 (2006.01)
CPC H02M 7/53871 (2013.01) [F04D 27/008 (2013.01); H02M 1/32 (2013.01); H02P 27/06 (2013.01)] 6 Claims
OG exemplary drawing
 
1. A control device comprising:
an electricity detection unit that detects a physical quantity of electricity pertaining to a head capacitor provided between a direct power supply and switching elements of an inverter; and
a protection control unit configured to control the switching elements of the inverter such that no current flows to the head capacitor in response to a value of the physical quantity of the electricity being smaller than a magnitude criterion and where a decrease rate of physical quantity of the electricity is greater than a predetermined value and a motor, whose drive circuit is the inverter, operates,
wherein the protection control unit is further configured to in response to the value of the physical quantity of the electricity being smaller than the magnitude criterion, determine an absolute value of a slope of a change in physical quantity of the electricity and determine if the absolute value of the slope is greater than a predetermined value to determine that the decrease rate in physical quantity of the electricity is greater than the predetermined value and in response to the value of the physical quantity of the electricity not being smaller than the magnitude criterion, not determine the absolute value of the slope of the change in physical quantity of the electricity.