US 12,362,569 B2
Maximum power point tracking device and operation method thereof
Po-Hao Pan, Taipei (TW)
Assigned to LITE-ON TECHNOLOGY CORPORATION, Taipei (TW)
Filed by LITE-ON TECHNOLOGY CORPORATION, Taipei (TW)
Filed on Dec. 1, 2023, as Appl. No. 18/525,911.
Claims priority of application No. 112108535 (TW), filed on Mar. 8, 2023.
Prior Publication US 2024/0305104 A1, Sep. 12, 2024
Int. Cl. H02J 3/38 (2006.01); H02M 1/00 (2006.01)
CPC H02J 3/38 (2013.01) [H02J 3/381 (2013.01); H02J 2300/26 (2020.01); H02M 1/0006 (2021.05); Y02E 10/56 (2013.01)] 12 Claims
OG exemplary drawing
 
1. A maximum power point tracking (MPPT) device, comprising:
a DC-to-DC converting circuit, connected to a photovoltaic array (PV array);
a DC-to-AC inverting circuit, connected to the DC-to-DC converting circuit; a controlling circuit, connected to the DC-to-DC converting circuit and the DC-to-AC inverting circuit;
an auxiliary power supply, connected to the DC-to-DC converting circuit, the DC-to-AC inverting circuit and the controlling circuit, for providing a power;
a power limiting circuit, connected to the photovoltaic array and the auxiliary power supply, wherein the power limiting circuit includes:
a dummy load path, used to provide a dummy load, when a photovoltaic power of the photovoltaic array is lower than a predetermined power, so as to stabilize a photovoltaic voltage of the photovoltaic array; and
an auxiliary power providing path, used to enable the auxiliary power supply, when the photovoltaic power of the photovoltaic array is higher than or equal to the predetermined power;
wherein the power limiting circuit further comprises a second transistor, connected to a second resistor, wherein when the second transistor is turned on, the second resistor and the second transistor form the auxiliary power providing path and release the dummy load;
wherein the power limiting circuit further comprises a second capacitor connected to the second transistor, a fourth resistor, and a fifth resistor, wherein the second capacitor is connected to a second node connected between the fourth resistor and the fifth resistor, wherein when the second capacitor is charged to a second predetermined voltage by a second divided voltage between the fourth resistor and the fifth resistor, the second transistor is turned on to form the auxiliary power providing path; and
a flyback circuit, connected to the auxiliary power supply, and wherein the power limiting circuit further comprises a diode, the second capacitor is connected to the diode, the diode is connected to a power supply voltage node connected between the flyback circuit and the auxiliary power supply to provide a power supply voltage for charging the second capacitor.