Power supply component

Abstract

A power supply assembly includes an AC main power connection (41), a DC secondary power connection (42), an AC load connection (71), a DC link (2), a DC converter (81) electrically connected between the secondary power connection (42) and the DC link (2), and a load power converter (82) electrically connected between the DC link (2) and the load connection (71). The power supply assembly (101) includes a trickle charger converter (84) electrically connected between at least one AC connection and the secondary power connection (42), and the nominal power of the trickle charger converter (84) is less than the nominal powers of the DC converter (81) and the load power converter (82).

Description

Technical Field

[0001] The present invention relates to a power supply assembly, and more particularly to an uninterruptible power supply assembly. Background Art

[0002] An uninterruptible power supply (UPS) is an electrical device that provides emergency power to a load when the main AC power supply fails. The UPS differs from a backup generator in that it is adapted to provide emergency power almost immediately after a failure of the main AC power supply. The uninterruptible power supply is adapted to provide energy stored in, for example, a battery, a supercapacitor, or a flywheel.

[0003] Known power supply assemblies include a DC power supply, a DC (direct current) link, an AC load connection, a DC converter, and a load power converter, wherein the power supply assembly is adapted to supply power from the DC power supply to the AC load connection through the DC converter, the DC link, and the load power converter. Examples of known uninterruptible power supply assemblies are described in the publications WO2018 / 234046 and EP3088989.

[0004] One of the disadvantages associated with the above power supply assembly is that both the DC converter and the load power converter must be rated for the total power supplied from the DC power supply to the AC load connection, which means a relatively poor coefficient of efficiency during additional operations. Herein, additional operations include charging the DC power supply from the DC link through the DC converter, and compensating for reactive power at the AC load connection through the load power converter. The coefficient of efficiency of the DC converter and the load power converter is low during additional operations because their load during additional operations is typically much lower than their nominal power. Summary of the Invention

[0005] The object of the present invention is to provide a power supply assembly to alleviate the above disadvantages. The object of the present invention is achieved by the power supply assembly described below.

[0006] The present invention is based on the concept of providing a power supply assembly having a separate trickle charger converter adapted to charge the DC power supply. The trickle charger converter is electrically connected between the AC connection and the DC power supply, and the nominal power of the trickle charger converter is less than the nominal power of the DC converter and the load power converter.

[0007] The advantage of the power supply assembly of the present invention is a high coefficient of efficiency during the trickle charging operation of charging the DC power supply through the trickle charger converter. Since it is not necessary to supply power through the DC converter and the load power converter having a high nominal power and relatively high losses at a small partial load during the trickle charging operation, the energy efficiency is improved.

[0008] In addition, when charging a DC power supply through a trickle charger converter, the charging power passes through only one converter, i.e., the trickle charger converter. If charging the DC power supply from an AC load connection through a load power converter and a DC converter, the charging power passes through two converters both having a high nominal power. Therefore, charging the DC power supply through the trickle charger converter is more energy-efficient than charging the DC power supply through the load power converter and the DC converter. Description of the Drawings

[0009] The present invention will be described in more detail below with reference to the drawings by means of preferred embodiments, in which:

[0010] Figure 1 A power supply assembly according to an embodiment of the present invention is shown. Detailed Description of the Embodiments

[0011] Figure 1 A power supply assembly 101 is shown, which includes a power connection system 4, a load connection 71, a DC link 2, a DC converter 81, a load power converter 82, a trickle charger converter 84, a power switch 5, a control system 909, and a rechargeable DC power supply 461.

[0012] The power connection system 4 includes a main power connection 41 adapted to be electrically connected to a main AC power supply 301 and a secondary power connection 42 adapted to be electrically connected to a secondary power supply (an example of the secondary power supply may be a current source). The secondary power connection 42 is a DC connection. The load connection 71 is adapted to be electrically connected to an AC load 707.

[0013] The DC converter 81 is electrically connected between the secondary power connection 42 and the DC link 2. The DC converter 81 is adapted to supply power from the secondary power connection 42 to the DC link 2. The DC link 2 includes a DC link capacitor.

[0014] The load power converter 82 is electrically connected between the DC link 2 and the load connection 71. The load power converter 82 is adapted to supply power from the DC link 2 to the load connection 71.

[0015] A power conversion filter 829 is electrically connected between the load power converter 82 and the load connection 71. The power conversion filter 829 includes a filter capacitor. Due to its relatively high capacitance, the power conversion filter 829 causes significant reactive power in the power supply assembly.

[0016] The trickle charger converter 84 is electrically connected between the load connection 71 and the secondary power connection 42. A trickle charger capacitor 24 is electrically connected between the secondary power connection 42 and the trickle charger converter 84.

[0017] The trickle charger converter 84 is adapted to supply power from the load connection 71 to the secondary power connection 42. The nominal power of the trickle charger converter 84 is less than the nominal powers of the DC converter 81 and the load power converter 82.

[0018] The nominal power of the DC converter 81 is equal to the nominal power of the load power converter 82. The nominal power of the trickle charger converter 84 is 5% of the nominal power of the DC converter 81. In an alternative embodiment, the nominal power of the trickle charger converter is less than or equal to 15% of the nominal power of the DC converter. In another alternative embodiment, the nominal power of the trickle charger converter is in the range of 1% to 10% of the nominal power of the DC converter. In yet another alternative embodiment, the nominal power of the trickle charger converter is in the range of 1% to 10% of the nominal power of the load power converter.

[0019] There is internal electrical isolation between the AC side and the DC side of the trickle charger converter. In an embodiment, the electrical isolation is adapted to operate at the converter pulse width modulation frequency.

[0020] The trickle charger converter 84 has a different topology from the load power converter 82 and uses different types of semiconductor switches. The trickle charger converter 84 is based on a very low-loss topology such as a resonant topology. The trickle charger converter 84 is based on a soft-switching topology. The trickle charger converter 84 utilizes wide-bandgap semiconductors such as silicon carbide (SiC) or gallium nitride (GaN) semiconductors. The trickle charger converter 84 is designed to always maintain an optimal operating point.

[0021] In an alternative embodiment, the trickle charger converter has the same topology as the load power converter and they both use the same type of semiconductor switches. The trickle charger converter and the load power converter can even be identical to each other, except for their nominal powers.

[0022] In an alternative embodiment, the trickle charger converter is electrically connected between at least one AC connection and the secondary power connection, and the trickle charger converter is adapted to supply power from at least one AC connection to at least one secondary power connection. The at least one AC connection includes at least one of the load connection and the main power connection.

[0023] In an embodiment, the trickle charger converter, the DC converter, and the load power converter are located in a common housing. In an alternative embodiment, the trickle charger converter is located in a housing different from the DC converter and the load power converter.

[0024] In an alternative embodiment, the power supply assembly includes a plurality of secondary power connections, each secondary power connection being adapted to be electrically connected to a different secondary power source. The different secondary power sources include different types of DC power sources, such as batteries and capacitors.

[0025] The main power connection 41 is conductively connected to the load connection 71 through the AC power supply line 457 to supply power from the main power connection 41 to the load connection 71. The power switch 5 is adapted to disconnect the AC power supply line 457, thereby disconnecting the main power connection 41 from the load connection 71.

[0026] The control system 909 is adapted to control the DC converter 81, the load power converter 82, the trickle charger converter 84, and the power switch 5.

[0027] The control system 909 is adapted to provide an energy-saving mode, a DC power supply mode, a charging mode, a trickle charging mode, and a reactive power compensation mode for the power supply assembly.

[0028] In the energy-saving mode, the power switch 5 is in the on state to supply power from the main power connection 41 to the load connection 71. In an embodiment, the DC converter and the load power converter are in the standby state during the energy-saving mode. In an alternative embodiment, the DC converter and the load power converter are in the off state during the energy-saving mode. Herein, the standby state is a state where there is no current in the semiconductor switches of the converter, and only the control circuit of the converter consumes very little power.

[0029] In the DC power supply mode, the power switch 5 is in the non-conductive state, and power is supplied from the secondary power connection 42 to the load connection 71 through the DC converter 81 and the load power converter 82. In an embodiment, the trickle charger converter also participates in supplying power to the load connection during the DC power supply mode. The participation of the trickle charger converter in supplying power to the load connection during the DC power supply mode increases the total power that can be supplied to the load connection during the DC power supply mode.

[0030] In the charging mode, power is supplied from the DC link 2 to the secondary power connection 42 through the DC converter 81. In an embodiment, the trickle charger converter also participates in supplying power to the secondary power connection during the charging mode.

[0031] In the trickle charging mode, power is supplied from the load connection 71 to the secondary power connection 42 exclusively through the trickle charger converter 84. Power is not supplied to the secondary power connection 42 through the DC converter 81.

[0032] The power of the charging mode is higher than the nominal power of the trickle charger converter. The charging mode is adapted to quickly replenish the rechargeable DC power source 461 when there is no time to slowly recharge the rechargeable DC power source 461 through the trickle charger converter 84.

[0033] In an embodiment, the DC converter is in an off state during the trickle charge mode. In an alternative embodiment, the DC converter is in a standby state during the trickle charge mode.

[0034] In the reactive power compensation mode, reactive power is supplied from the trickle charger converter 84 to the load connection 71. In an embodiment, reactive power is specifically supplied from the trickle charger converter to the load connection. In the said embodiment, the trickle charger converter is capable of compensating at least a part of the reactive power caused by the power converter filter.

[0035] In an alternative embodiment, reactive power is supplied to the load connection from both the trickle charger converter and the load power converter.

[0036] In Figure 1 the embodiment, each of the DC converter 81, the load power converter 82, and the trickle charger converter 84 is a bidirectional converter. In an embodiment where the trickle charger converter does not participate in power supply from the secondary power connection to the load connection, the trickle charger converter is a unidirectional converter. In another embodiment where power is not supplied from the load connection to the secondary power connection through the load power converter and the DC converter, the load power converter and the DC converter are unidirectional converters.

[0037] In Figure 1 the power supply assembly shown, the trickle charger converter 84 consists of a single unit. In an alternative embodiment, the trickle charger converter includes a plurality of units connected in parallel. In another alternative embodiment, the load power converter includes a plurality of units connected in parallel, and the DC converter includes a plurality of units connected in parallel.

[0038] It will be apparent to those skilled in the art that the inventive concept can be implemented in various ways. The present invention and its embodiments are not limited to the above examples, but can vary within the scope of the claims.

Claims

1. A power supply assembly, comprising: A power connection system (4), which includes a main power connection (41) adapted to be electrically connected to a main AC power supply (301) and at least one secondary power connection (42) adapted to be electrically connected to a secondary power supply (461), and the at least one secondary power connection (42) is a DC connection; A load connection (71), which is adapted to be electrically connected to an AC load (707); A DC link (2); A DC converter (81), which is electrically connected between the at least one secondary power connection (42) and the DC link (2), and the DC converter (81) is adapted to supply power from the at least one secondary power connection (42) to the DC link (2); A load power converter (82), which is electrically connected between the DC link (2) and the load connection (71), and the load power converter (82) is adapted to supply power from the DC link (2) to the load connection (71); and A power switch (5), which is adapted to disconnect the main power connection (41) from the load connection (71), characterized in that the power supply assembly (101) includes a trickle charger converter (84), the trickle charger converter is electrically connected between at least one AC connection and the at least one secondary power connection (42), the trickle charger converter (84) is adapted to supply power from the at least one AC connection to the at least one secondary power connection (42), and the nominal power of the trickle charger converter (84) is less than the nominal powers of the DC converter (81) and the load power converter (82), wherein the power supply assembly (101) includes a control system (909), and the control system (909) is adapted to control the DC converter (81), the load power converter (82), the trickle charger converter (84) and the power switch (5) wherein the trickle charger converter (84) has an AC side and a DC side; wherein the control system (909) is adapted to provide a charging mode for the power supply assembly, in which power is supplied from the DC link (2) to the at least one secondary power connection (42) through the DC converter (81); wherein the control system (909) is adapted to provide a trickle charging mode for the power supply assembly, in which power is supplied from the at least one AC connection to the at least one secondary power connection (42) through the trickle charger converter (84); wherein the nominal power of the trickle charger converter (84) is less than or equal to 15% of the nominal power of the DC converter (81).

2. The power supply assembly according to claim 1, wherein, the control system (909) is adapted to: provide an energy-saving mode for the power supply assembly, in which the power switch (5) is in a conducting state to supply power from the main power connection (41) to the load connection (71); and providing a DC power supply mode for the power supply component, in which the power switch (5) is in a non-conductive state, and power is supplied to the load connection (71) from the at least one secondary power connection (42) through the DC converter (81) and the load power converter (82).

3. The power supply component according to claim 1, wherein, the control system (909) is adapted to provide a reactive power compensation mode for the power supply component, in which reactive power is supplied from the trickle charger converter (84) to the at least one AC connection.

4. The power supply component according to claim 1, wherein, the at least one AC connection to which the AC side of the trickle charger converter (84) is connected includes at least one of the load connection (71) and the main power connection (41).

5. The power supply component according to claim 1, wherein, the nominal power of the trickle charger converter (84) is in the range of 1% to 10% of the nominal power of the DC converter (81).

6. The power supply component according to claim 1, wherein, the power supply component includes at least one rechargeable DC power supply (461) electrically connected to the at least one secondary power connection (42).

7. The power supply component according to claim 1, wherein, the trickle charger converter (84) has a different topology from the load power converter (82).

8. The power supply component according to claim 1, wherein, the trickle charger converter (84) uses a different type of semiconductor switch from the load power converter (82).

9. The power supply component according to claim 1, wherein, there is internal electrical isolation between the AC side and the DC side of the trickle charger converter (84).

10. The power supply component according to claim 1, wherein, the trickle charger converter (84) uses wide bandgap semiconductors.

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