US 11,936,327 B2
Hybrid power system with electric generator and auxiliary power source
Joseph Gehret, North Reading, MA (US); Robert A. Panora, Cambridge, MA (US); and Jian Wen, North Andover, MA (US)
Assigned to Tecogen Inc., Waltham, MA (US)
Filed by Tecogen Inc., Waltham, MA (US)
Filed on Jun. 23, 2022, as Appl. No. 17/808,430.
Claims priority of provisional application 63/214,019, filed on Jun. 23, 2021.
Prior Publication US 2022/0416700 A1, Dec. 29, 2022
Int. Cl. H02P 9/02 (2006.01); H02J 3/00 (2006.01)
CPC H02P 9/02 (2013.01) [H02J 3/00 (2013.01)] 15 Claims
OG exemplary drawing
 
1. A hybrid power-generator system comprising:
an engine that runs with a wide-open throttle;
an electric generator mechanically coupled to the engine to produce a generator alternating current (AC) having a frequency;
a first rectifier having an input that is electrically coupled to an output of the electric generator, the first rectifier configured to rectify the generator AC to a generator direct current (DC);
a second rectifier having an input that is electrically coupled to an electric grid to receive a grid AC, the second rectifier configured to rectify the grid AC to a grid DC;
a first DC-DC voltage converter having an input that is electrically coupled to an output of the first rectifier to receive the generator DC;
a second DC-DC voltage converter having an input that is electrically coupled to an output of the second rectifier to receive the grid DC;
a DC bus electrically coupled to an output of the first DC-DC voltage converter and to an output of the second DC-DC voltage converter;
an inverter electrically coupled to the DC bus, the inverter supplying an inverter AC to a load motor;
a first controller that receives as inputs a grid power target signal and a grid power feedback signal and produces an engine speed target signal based, at least in part, on the grid power target signal and the grid power feedback signal; and
a second controller that receives as inputs the engine speed target signal, an engine speed feedback signal, a DC bus voltage feedback signal, and a DC bus target voltage signal, and produces first and second duty-cycle output signals based, at least in part, on the engine speed target signal, the engine speed feedback signal, the DC bus voltage feedback signal, and the DC bus target voltage signal,
wherein:
the first duty-cycle output signal sets a duty cycle of the first DC-DC voltage converter,
the second duty-cycle output signal sets a duty cycle of the second DC-DC voltage converter, and
the duty cycle of the first DC-DC voltage converter causes the engine to operate at a corresponding speed.