US 12,438,443 B2
Controller for power conversion system
Issei Fukasawa, Tokyo (JP); and Masahiro Kinoshita, Tokyo (JP)
Assigned to TMEIC Corporation, Chuo-ku (JP)
Appl. No. 17/754,463
Filed by TMEIC Corporation, Chuo-ku (JP)
PCT Filed Dec. 10, 2019, PCT No. PCT/JP2019/048236
§ 371(c)(1), (2) Date Apr. 1, 2022,
PCT Pub. No. WO2021/117124, PCT Pub. Date Jun. 17, 2021.
Prior Publication US 2022/0385171 A1, Dec. 1, 2022
Int. Cl. H02M 1/32 (2007.01); H02J 3/38 (2006.01)
CPC H02M 1/327 (2021.05) [H02J 3/381 (2013.01); H02J 2300/24 (2020.01)] 3 Claims
OG exemplary drawing
 
1. A controller for a power conversion system, the controller comprising:
determination circuitry configured to determine whether a current time is in nighttime in an environment of a power converter that is connected between a solar cell and an alternating-current power supply; and
control circuitry configured, in a case that the determination circuitry determines that the current time is in the nighttime, to maintain a switch in a closed state, the switch being provided between the power converter and one of the alternating-current power supply and the solar cell, and to maintain power consumption by the power converter by operating the power converter,
wherein the power converter includes:
a direct-current capacitor connected between the solar cell and the power converter, and a direct-current discharge resistor connected in parallel with the direct-current capacitor, which are provided on a direct-current side, and
an alternating-current capacitor connected between the solar cell and the power converter, and an alternating-current discharge resistor connected in parallel with the alternating-current capacitor, which are provided on an alternating-current side,
wherein the power converter outputs reactive power so that the alternating-current capacitor cancels reactive power flowing out to a system side and generates heat by a loss of power conversion in a state where heat is generated by power consumption of the direct-current discharge resistor and the alternating-current discharge resistor by power from the alternating-current power supply in the nighttime, and
wherein the control circuitry includes means for noticing temperature, and closes the switch provided between the power converter and one of the alternating-current power supply and the solar cell in the nighttime only when the temperature is low.