Power supply system

Patent metadata

Field	Value
Publication number	US-12136871-B2
Application number	US-202318150999-A
Country	US
Kind code	B2
Filing date	Jan 6, 2023
Priority date	Jul 7, 2020
Publication date	Nov 5, 2024
Grant date	Nov 5, 2024

Abstract

An energy combiner apparatus is used to convert output of a power supply, and has three output terminals, so that output ports are increased. In the three output terminals of the energy combiner apparatus, a voltage of 1500 V is output between a first output terminal and a second output terminal, a voltage of 1500 V is also output between the second output terminal and a third output terminal, and a total of 3 kV is output. Therefore, an overall output voltage is increased in a case of equal output power. Because the overall output voltage is increased, a current transmitted on a cable may be reduced. Therefore, a thinner cable may be used, so that costs of the cable are reduced. In addition, four cables conventionally required for connecting to the output terminals of the energy combiner apparatus are reduced to three, so that quantity and costs are reduced.

First claim

What is claimed is:

1. A power supply system, comprising:
three phase circuits connected to a grid through either a star or delta connection;
at least one first power supply; and
at least one energy combiner apparatus, wherein each phase circuit comprises
a plurality of direct current/alternating current (DC/AC) conversion combinations and
a filter unit, output terminals of the plurality of DC/AC conversion combinations are cascaded, a first cascaded terminal is coupled to an input terminal of the filter unit, a first output terminal of the filter unit is used as a first output terminal of the phase circuit, and a second cascaded terminal is used as a second output terminal of the phase circuit;
each DC/AC conversion combination comprises:
a first-stage isolation DC/AC conversion unit and
a second-stage isolation DC/AC conversion unit, output terminals of the first-stage isolation DC/AC conversion unit and the second-stage isolation DC/AC conversion unit are cascaded, the first cascaded terminal is used as a first output terminal of the DC/AC conversion combination, and the second cascaded terminal is used as a second output terminal of each DC/AC conversion combination;
a first input terminal of the first-stage isolation DC/AC conversion unit is used as a first input terminal of the DC/AC conversion combination,
a second input terminal of the first-stage isolation DC/AC conversion unit is coupled to a first input terminal of the second-stage isolation DC/AC conversion unit,
a coupling node is used as a second input terminal of the DC/AC conversion combination, and
a second input terminal of the second-stage isolation DC/AC conversion unit is used as a third input terminal of the DC/AC conversion combination; and
an input terminal of the energy combiner apparatus is coupled to an output terminal of the at least one first power supply, and
the three input terminals of the DC/AC conversion combination are coupled to three output terminals of the at least one energy combiner apparatus.

2. The power supply system according to claim 1 , wherein same-type output terminals of energy combiner apparatuses are connected in parallel, same-type input terminals of the DC/AC conversion combinations are connected in parallel, and the parallel output terminals of the energy combiner apparatuses are coupled to the parallel input terminals of the DC/AC conversion combinations; or
same-type input terminals of DC/AC conversion combinations in a same phase circuit are connected in parallel, and the same-type input terminals connected in parallel are coupled to output terminals of the at least one energy combiner apparatus; or
an input terminal of each DC/AC conversion combination is coupled to the at least one energy combiner apparatus.

3. The power supply system according to claim 1 , wherein the first power supply is a photovoltaic array and/or an energy storage power supply and/or a wind power generation DC source; and the photovoltaic array is formed by
connecting photovoltaic panels in series and parallel, or is formed by
connecting outputs of photovoltaic panels to optimizers or shutdown devices and then performing a combination of series and parallel connections.

4. The power supply system according to claim 1 , wherein the energy combiner apparatus comprises
a DC/DC conversion unit that has a unidirectional step-up DC conversion function, a unidirectional step-down DC conversion function, a bidirectional step-up/step-down DC conversion function, or a unidirectional step-up and reverse step-down DC conversion function, wherein an input terminal of the DC/DC conversion unit is coupled to the input terminal of the energy combiner apparatus, three output terminals of the DC/DC conversion unit are coupled to the three output terminals of the energy combiner apparatus, and the output terminals of the DC/DC conversion unit comprise:
a positive output terminal of the DC/DC conversion unit;
a negative output terminal of the DC/DC conversion unit; and
an output-voltage intermediate-potential output terminal of the DC/DC conversion unit.

5. The power supply system according to claim 4 , wherein the DC/DC conversion unit comprises:
a first-stage DC/DC conversion unit and
a second-stage DC/DC conversion unit, an input terminal of the first-stage DC/DC conversion unit is the input terminal of the DC/DC conversion unit, an output terminal of the second-stage DC/DC conversion unit is an output terminal of the DC/DC conversion unit, an input terminal of the second-stage DC/DC conversion unit comprises:
a third node coupled to a positive output terminal of the first-stage DC/DC conversion unit and a positive output terminal of the second-stage DC/DC conversion unit;
a fourth node coupled to a negative output terminal of the first-stage DC/DC conversion unit and an output-voltage intermediate-potential output terminal of the second-stage DC/DC conversion unit; and
a fifth node coupled to a negative output terminal of the second-stage DC/DC conversion unit, and the second-stage DC/DC conversion unit is configured to transfer energy between the third node and the fourth node to a position between the fourth node and the fifth node, so that an average voltage from the third node to the fifth node is greater than an average voltage from the third node to the fourth node.

6. The power supply system according to claim 5 , wherein, when an input voltage and/or an input current and/or input power of the first-stage DC/DC conversion unit exceed or exceeds a preset value, the first-stage DC/DC conversion unit works in a bypass mode; and/or
when an output voltage and/or an output current and/or output power of the first-stage DC/DC conversion unit exceed or exceeds the preset value, the second-stage DC/DC conversion unit stops working; and/or
at least one of the first-stage isolation DC/AC conversion unit and the second-stage isolation DC/AC conversion unit works.

7. The power supply system according to claim 4 , wherein the DC/DC conversion unit comprises:
a third-stage DC/DC conversion unit and
a fourth-stage DC/DC conversion unit, an input terminal of the third-stage DC/DC conversion unit is the input terminal of the DC/DC conversion unit, an output terminal of the fourth-stage DC/DC conversion unit is an output terminal of the DC/DC conversion unit, and an input terminal of the fourth-stage DC/DC conversion unit comprises:
a sixth node coupled to a positive output terminal of the fourth-stage DC/DC conversion unit;
a seventh node coupled to a positive output terminal of the third-stage DC/DC conversion unit and an output-voltage intermediate-potential output terminal of the fourth-stage DC/DC conversion unit; and
an eighth node coupled to a negative output terminal of the third-stage DC/DC conversion unit and a negative output terminal of the fourth-stage DC/DC conversion unit, and the fourth-stage DC/DC conversion unit is configured to transfer energy between the seventh node and the eighth node to a position between the sixth node and the seventh node, so that an average voltage from the sixth node to the eighth node is greater than an average voltage from the seventh node to the eighth node.

8. The power supply system according to claim 7 , wherein, when an input voltage and/or input power of the third-stage DC/DC conversion unit exceed or exceeds a preset value, the third-stage DC/DC conversion unit works in a bypass mode; and/or
when an output voltage and/or output power of the third-stage DC/DC conversion unit exceed or exceeds the preset value, the fourth-stage DC/DC conversion unit stops working; and/or
at least one of the first-stage isolation DC/AC conversion unit and the second-stage isolation DC/AC conversion unit works.

Assignees

• Huawei Digital Power Tech Co Ltd

Inventors

• Zhang Yanzhong
• Wang Xun

Classifications

• H02J2101/24

  Photovoltaics · CPC title

• H02J2101/20

  Dispersed power generation using renewable energy sources · CPC title

• H02M7/493

  the static converters being arranged for operation in parallel · CPC title

• H02M5/12

  for conversion of voltage or current amplitude only · CPC title

• H02M3/06

  using resistors or capacitors, e.g. potential divider · CPC title