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EP-3701612-B1 - POWER ELECTRONICS CONDITIONING SYSTEM WITH HALF-WINDING GENERATOR SETUP

EP3701612B1EP 3701612 B1EP3701612 B1EP 3701612B1EP-3701612-B1

Inventors

  • ERNEST, EMIL
  • PACIURA, Krzysztof
  • PALMER, BRADFORD K.

Dates

Publication Date
20260513
Application Date
20181022

Claims (8)

  1. A power generation system (100) comprising: an inverter (140) configured to convert a direct current, DC, power from an external power source (110) to an alternating current, AC, power, the inverter (140) comprising at least one phase for converting the DC power to a corresponding phase of AC power; a generator set (120) having an alternator (124), the alternator comprising at least one phase, wherein each phase of the alternator comprises a first winding section (204) and a second winding section (206) coupled in series between a point of common coupling (N) and an output terminal (A) of the phase, with one terminal of each first winding section (204) connected to the common coupling (N); and a controller (114); wherein each phase of the inverter (140) corresponds to one phase of the alternator (124) and is connected in parallel with the first winding section of the corresponding phase of the alternator characterised in that the controller (114) is configured to: operate the generator set (120) and the inverter (140) according to one of a first mode, a second mode, and a third mode, wherein the controller (114) is configured to cause the generator set (120) to provide power to a load (160) in the first mode, wherein the controller (114) is configured to control the inverter (140) to provide power from the external power source (110) to the load (160) in the second mode, and wherein the controller (114) is configured to control the generator set (120) and the inverter (140) to power the load (160) from both the generator set (120) and the external power source (110) in the third mode.
  2. The power generation system of claim 1, wherein the inverter (140) comprises three phases and the alternator (124) comprises three phases.
  3. The power generation system of claim 2, wherein the controller (114) is configured according to at least one of the following: - to operate the generator set (120) and the inverter (140) in the third mode in response to a power demand of the load (160) exceeding a threshold value; and - to operate the generator set (120) and the inverter (140) in the third mode in response to an energy level of the external power source (110) being less than a threshold value, wherein the external power source (110) is configured to supply reactive power to the load (160) and the generator set (120) is configured to decrease a supply of reactive power to the load.
  4. The power generation system of any of the preceding claims, wherein the generator set (120) is configured for connection to an AC micro-grid (112) electrically connected to a grid (150), and wherein the inverter (140) is configured to connect the external power source (110) to the AC micro-grid (112).
  5. The power generation system of any of the preceding claims, wherein at least one phase of the inverter comprises an LCL filter circuit, wherein the at least one phase of the inverter comprises an LC filter circuit, and wherein the LC filter circuit (314, 316) and the first winding section (322) of the corresponding phase of the alternator (124) are configured to form the LCL filter circuit.
  6. The power generation system of claim 1, wherein the external power source comprises an energy storage device (118).
  7. The power generation system of claim 6, wherein the controller (114) is configured according to at least one of the following: - to operate the inverter (140) to charge the energy storage device (118) in response to a power demand of the load (160) being less than a threshold value; - to operate the inverter (140) to provide active harmonics damping of an output of the generator set (120); and - to provide power factor correction of an output of the generator set.
  8. The power generation system of claim 6 or 7, wherein at least one phase of the inverter (140) comprises an LCL filter circuit configured to passively reduce harmonics of the inverter, wherein the at least one phase of the inverter comprises an LC filter circuit (314, 316), and wherein the LC filter circuit and the first winding section of the corresponding phase of the alternator (124) are configured to form the LCL filter circuit

Description

The present disclosure generally relates to power generation systems. Autonomous alternating current (AC) micro-grids have been widely used in power generation and distribution systems. An autonomous AC micro-grid often includes a generator set (also referred to as "genset"), which may have an engine powered by fuel. The engine may be operatively coupled to an alternator, and the alternator may be configured to generate electrical energy for providing power to the autonomous AC micro-grid. A hybrid power generation system may include one or more supplemental power sources for providing power to an autonomous AC micro-grid. A supplemental power source may relate to an alternative energy system, which may include a renewable energy source (e.g., solar energy, wind energy) or an energy storage device (e.g., battery pack, ultra-capacitor). In order to supply power to load, a renewable energy source and/or an energy storage device can be coupled to an autonomous AC micro-grid through a direct current (DC) to alternating current (AC) inverter. There is a challenge of achieving the desirable operation for the hybrid power generation system. DE 10 2015 218416 A1 discloses a power circuit which is used for supplying power in an electrically powered vehicle. The power circuit comprises an external AC voltage connection, at least one DC / AC converter, which has an AC voltage side, and an electrical machine with a plurality of windings, each of which has a first tap. The electrical machine is connected to the AC voltage side of the DC / AC converter. WO 2015/150740 A1 discloses a power generation system is disclosed comprising an electrical generating set and a power module for supplying power from a supplementary power source. The power module comprises a DC to AC converter. The power generation system comprises means for measuring an output of the electrical generating set, and a controller for controlling the DC to AC converter, wherein the controller is arranged to control the DC to AC converter in dependence on a measure of the output of the electrical generating set. US 2011/316462 A1 discloses an electric device for driving mechanical equipment comprising an alternating current motor and an inverter, the said inverter comprising, for each phase of the said motor, an H bridge structure comprising four switching elements distributed over two branches connecting two terminals of the said H bridge structure and intended to supply the winding of the said at least one phase of the motor, the said winding being a winding with a mid point and the said electric device being characterized in that it also comprises, for each phase of the said motor, an energy storage unit, in particular a supercondenser, connected, on the one hand, to the mid point of the winding of the concerned phase of the motor and, on the other hand, to a terminal of the H bridge structure supplying the said winding. WO2016/207481 A1 discloses an electrical drive comprising an electrical machine, a first converter stage connected to terminals of stator phase-windings of the electrical machine, and a second converter stage connected to intermediate points of the stator phase-windings. A control device determines first component currents and second component currents so that torque is generated in accordance with electrical machine control and magnetic levitation force is directed to a rotor of the electrical machine in accordance with levitation control when portions of the phase-windings between the terminals and the intermediate points carry both the first and second component currents and the other portions of the phase-windings carry the first component currents. The reference currents for the first converter stage are determined based on the first and second component currents, and the reference currents for the second converter stage are determined based on the second component currents. SUMMARY OF THE INVENTION According to the present invention, there is provided a power generation system according to claim 1. Preferred features of the invention are recited in the dependent claims. In one aspect, the invention disclosed herein is directed to a power generation system comprising an inverter and a generator set. The inverter is configured to convert a direct current (DC) power from an external power source to an alternating current (AC) power. The inverter includes at least one phase for converting the DC power to a corresponding phase of AC power. The generator set includes an alternator. The alternator includes at least one phase, wherein each phase of the alternator comprises a first winding section and a second winding section coupled in series between a point of common coupling and an output terminal of the phase. Each phase of the inverter corresponds to one phase of the alternator and is connected in parallel with the first winding section of the corresponding phase of the alternator. In some embodiments, the inverter includes three phase