Patent Description:
With the vigorous development of network and cloud services, data centers have become common solutions for cloud computing, network service businesses and operations. A data center typically has computing server racks configured to provide data processing and data storage functions, telecommunication and network equipment (e.g., switches and routers) for communication transmission, and power supply equipment. Therefore, the power supply equipment of the data center is often provided with a backup power system, such as a power supply unit (PSU), an uninterrupted power system (UPS), or a power generator so as to avoid the shutdown of the data center. The documents <CIT>, <CIT>, <CIT> , <CIT> disclose different concepts of uninterrupted power systems.

After the design of the data center or the power supply equipment having a plurality of computing servers is completed, an efficiency line of the power supply equipment is then fixed. However, since the used times and loads of the computing server racks are not completely the same, it is difficult to maintain the data center at a relatively high load efficiency, thus reducing the power conversion efficiency. Therefore, how to effectively manage power of the data center to thus save power consumption without power failure of the data center is one of the research directions.

The disclosure provides a power supply system and a control method thereof, in which power management allows a power supply device that controls the power supply system to be positioned at a load point with a relatively high conversion efficiency as much as possible to obtain the optimal energy use efficiency.

An embodiment of the disclosure provides a power supply system configured to supply power to a load. The power supply system includes a power supply device and a backup power device. The power supply device supplies power to the load. The backup power device includes a backup battery pack, a charging converter, a discharging converter, and a processor. The charging converter is coupled to the backup battery pack. The discharging converter is coupled to the backup battery pack. The processor is coupled to the power supply device, the backup battery pack, the charging converter, and the discharging converter. The processor determines whether a status of the backup power device is a load mode or a power supply mode according to a current conversion efficiency of the power supply device. In response to the power supply mode, the processor controls the backup battery pack, such that the backup battery pack and the power supply device simultaneously supply power to the load.

An embodiment of the disclosure provides a control method of a power supply system. The power supply system is configured to supply power to a load. The control method includes the following. It is determined whether a status of a backup power device is a load mode or a power supply mode according to a current conversion efficiency of a power supply device. The power supply system includes the power supply device and the backup power device. In response to the power supply mode, a backup battery pack of the backup power device is controlled, such that the backup battery pack and the power supply device simultaneously supply power to the load.

An embodiment of the disclosure provides a power supply system, which includes a power supply device and a backup power device. The power supply device is configured to supply power through a power bus. The backup power device includes a backup battery pack, a power converter, and a processor. The power converter is coupled to the backup battery pack and the power bus. The processor is coupled to the power supply device, the backup battery pack, and the power converter. The processor controls the backup battery pack and the power converter according to a current conversion efficiency of the power supply device, such that the backup battery pack performs switching to a charge mode or a discharge mode through the power converter.

Based on the foregoing, in the power supply system and the control method thereof described in the embodiments of the disclosure, the load of the power supply device is controlled by charging or discharging of the backup power device, so that the load of the power supply device is positioned at a load point with a relatively high conversion efficiency as much as possible. In other words, in the embodiments of the disclosure, it is determined whether the status of the backup power device is a load mode or a power supply mode. When the status of the backup power device is the load mode, the backup power device is charged to maintain the power supply device at a load point with a relatively high conversion efficiency. In addition, when the status of the backup power device is the power supply mode, the backup power device is made to supply power to the computing server to share the load of the power supply device. The power supply device is maintained at a load point with a relatively high conversion efficiency, thus the optimal energy use efficiency is obtained.

To make the aforementioned more comprehensible, several embodiments accompanied with drawings are described in detail as follows.

The drawings illustrate exemplary embodiments of the disclosure and, together with the description, serve to explain the principles of the disclosure.

<FIG> is a block diagram of a data center <NUM> according to an embodiment of the disclosure. The data center <NUM> mainly includes a power supply system <NUM> and a load. The load referred to in this embodiment may include at least one computing server <NUM>. In other words, the power supply system <NUM> of this embodiment is mainly applied to the data center <NUM> to supply power to the computing server <NUM> of the data center <NUM>, but it is not limited to this.

The power supply system <NUM> mainly includes a power supply device <NUM> and a backup power device <NUM>. Utilizing AC power or other power supplies, the power supply device <NUM> supplies power to the at least one computing server <NUM> of the data center <NUM> through a power bus PBUS (as indicated by arrow A1). The power supply device <NUM> of this embodiment may also have a plurality of power supply units (PSU) PSU to serve as a backup for the power supply device <NUM>. In this embodiment, the computing server <NUM> of the data center <NUM> is formed by a plurality of computers or servers connected to each other to serve as the main load of the data center <NUM>.

The backup power device <NUM> includes a backup battery pack <NUM>, a power converter <NUM>, and a processor <NUM>. In an embodiment, the power converter <NUM> is coupled to the backup battery pack <NUM> and the power bus PBUS. The power converter <NUM> includes a charging converter <NUM> and a discharging converter <NUM>. The charging converter <NUM> is coupled to the backup battery pack <NUM> and the power bus PBUS, and the charging converter <NUM> is indirectly coupled to the power supply device <NUM> through the power bus PBUS. The discharging converter <NUM> is coupled to the backup battery pack <NUM> and the power bus PBUS, and the discharging converter <NUM> is indirectly coupled to the computing server <NUM> through the power bus PBUS. The charging converter <NUM> and the discharging converter <NUM> are each coupled between the backup battery pack <NUM> and the power bus PBUS.

The charging converter <NUM> and the discharging converter <NUM> of this embodiment are implemented by a DC/DC converter with a constant current (CC)/constant voltage (CV) mode. To be specific, the charging converter <NUM> is configured to provide power from the power bus PBUS to the backup battery pack <NUM> (as indicated by arrow A2) to charge the backup battery pack <NUM>. The discharging converter <NUM> is configured to provide power stored in the backup battery pack <NUM> through the power bus PBUS to the computing server <NUM> (as indicated by arrow A3) to discharge the backup battery pack <NUM>. Therefore, the backup power device <NUM> of this embodiment may not only serve as the load of the data center <NUM> but also serve as the power supply of the data center <NUM>. The backup power device <NUM> controls the current in the power bus PBUS to make it controllable by using the DC-to-DC converter with a CC/CV mode.

The backup battery pack <NUM> of this embodiment may have a plurality of backup battery units (BBU) BBU. The processor <NUM> may control the backup battery units BBU in the backup battery pack <NUM> to be selectively charged or discharged. For example, the processor <NUM> does not need to charge the backup battery units BBU at the same time and may selectively charge one or N of the backup battery units BBU in the backup battery pack <NUM>, and then correspondingly increases the load of the power supply device by adjusting the number of backup battery units BBU to be charged. The processor <NUM> does not need to discharge the backup battery units BBU at the same time and may selectively discharge one or N of the backup battery units BBU to supply power to the computing server <NUM>, and then correspondingly reduces the load of the power supply device. In addition, the processor <NUM> may discharge the fully charged backup battery units BBU in priority, thus releasing power.

The processor <NUM> is coupled to the power supply device <NUM>, the backup battery pack <NUM>, the charging converter <NUM>, and the discharging converter <NUM>. The processor determines whether a status of the backup power device <NUM> is a load mode or a power supply mode according to a current conversion efficiency of the power supply device <NUM>. From another perspective according to the embodiment of the disclosure, the processor <NUM> controls the backup battery pack <NUM> and the power converter <NUM> according to the current conversion efficiency of the power supply device <NUM>, so that the backup battery pack <NUM> performs switching to a charge mode or a discharge mode through the power converter <NUM>. If the processor <NUM> determines that the status of the backup power device <NUM> is the power supply mode (i.e., the processor <NUM> causes the backup battery pack <NUM> to perform switching to the discharge mode through the power converter <NUM>), the processor <NUM> controls the backup battery pack <NUM> to supply power to the power bus PBUS through the discharging converter <NUM>, so that the backup battery pack <NUM> and the power supply device <NUM> simultaneously supply power to the computing server <NUM> of the data center <NUM>. In addition, if the processor <NUM> determines that the status of the backup power device <NUM> is the load mode (i.e., the processor <NUM> causes the backup battery pack <NUM> to perform switching to the charge mode through the power converter <NUM>), the processor <NUM> controls the backup battery pack <NUM> to be charged through the power bus PBUS, so that the power supply device <NUM> charges the backup battery pack <NUM> while supplying power to the computing server <NUM> of the data center <NUM>.

It is herein described how to determine whether the status of the backup power device <NUM> is the load mode (i.e., the backup battery pack <NUM> caused to perform switching to the charge mode) or the power supply mode (i.e., the backup battery pack <NUM> caused to perform switching to the discharge mode) according to the current conversion efficiency of the power supply device <NUM>. The above description of "the backup battery pack <NUM> caused to perform switching to the charge mode" may also be referred to as the backup battery pack <NUM> switched to the charge mode and performing the charge mode; and the above description of "the backup battery pack <NUM> caused to perform switching to the discharge mode" may also be referred to as the backup battery pack <NUM> switched to the discharge mode and performing the discharge mode. <FIG> is a line chart of an efficiency of the power supply device <NUM> according to an embodiment of the disclosure. For example, this embodiment is designed so that the power supply device <NUM> provides <NUM> watts of power, and its efficiency line is composed of a plurality of conversion efficiency points as shown in <FIG>. The horizontal axis of <FIG> presents the load of the power supply device <NUM> (presented as a percentage (%)), and the vertical axis presents the conversion efficiency of the power supply device <NUM> for power (presented as a percentage (%)). In <FIG>, a conversion efficiency point PR1 of the power supply device <NUM> is the optimal conversion efficiency point (a conversion efficiency of about <NUM>%) of the power supply device <NUM>. At this time, the optimal conversion efficiency point PR1 corresponds to a <NUM>% load of the power supply device <NUM>. Intervals R2R and R3R that are close to the conversion efficiency point PR1 are line segments composed of other conversion efficiency points that are approximate to the optimal conversion efficiency point of <NUM>%.

A conversion efficiency interval R2 of the power supply device <NUM> is a light load interval (a load between about <NUM>% and <NUM>% of the power supply device <NUM>) of the power supply device <NUM>. At this time, the conversion efficiency of power is relatively low, increasing from a conversion efficiency of about <NUM>% corresponding to a load of <NUM>% to a conversion efficiency of about <NUM>% corresponding to a load of <NUM>%. At this time, if it is intended that the power supply device <NUM> enters the optimal conversion efficiency point PR1, then the status of the backup power device <NUM> may be set to the load mode. That is, the backup battery pack <NUM> may be switched to the charge mode to increase the load of the power supply device <NUM> so that the conversion efficiency approaches the optimal conversion efficiency point PR1. Therefore, the conversion efficiency interval R2 of the power supply device <NUM> is also the load mode of the backup power device <NUM>. According to some embodiments of the disclosure, since the conversion efficiency points in the intervals R2R and R3R are also approximate to the optimal conversion efficiency point PR1, those applying this embodiment may also accordingly set the status of the backup power device <NUM> to the load mode (to cause the backup battery pack <NUM> to perform switching to the charge mode), so that the conversion efficiency of the power supply device <NUM> enters the intervals R2R and R3R corresponding to the conversion efficiency point PR1. As such, the current conversion efficiency of the power supply device <NUM> may be determined according to the conversion efficiency intervals R2R and R3R corresponding to the conversion efficiency point PR1.

A conversion efficiency interval R3 of the power supply device <NUM> is an overload interval (a load of about <NUM>% to <NUM>%) of the power supply device <NUM>. At this time, the conversion efficiency of power is gradually reduced from a conversion efficiency of <NUM>% corresponding to a load of <NUM>% to be close to a conversion efficiency of <NUM>% corresponding to a load of <NUM>%. At this time, if it is intended that the power supply device <NUM> enters the optimal conversion efficiency point PR1, then the status of the backup power device <NUM> may be set to the power supply mode. That is, the backup battery pack <NUM> may be switched to the discharge mode to reduce the load of the power supply device <NUM>. Therefore, the conversion efficiency interval R3 of the power supply device <NUM> is also the power supply mode of the backup power device <NUM>. According to some embodiments of the disclosure, since the conversion efficiency points in the intervals R2R and R3R are also approximate to the optimal conversion efficiency point PR1, those applying this embodiment may also accordingly set the status of the backup power device <NUM> to the power supply mode (to cause the backup battery pack <NUM> to perform switching to the discharge mode), so that the conversion efficiency of the power supply device <NUM> enters the intervals R2R and R3R.

In other words, after the design of the power supply device <NUM> in <FIG> is completed, the efficiency line of the power supply device <NUM> in <FIG> is then fixed. Therefore, the efficiency line may be obtained by measuring efficiency by an efficiency measuring instrument at each load point and then recording each conversion efficiency point in <FIG>. In addition, the optimal conversion efficiency point PR1 and the intervals R2R and R3R may be obtained from the efficiency line. The processor <NUM> obtains the conversion efficiency point PR1 of the power supply device <NUM>, and determines the current conversion efficiency of the power supply device <NUM> according to the conversion efficiency point PR1 to determine whether a status of the power supply device <NUM> is a load mode or a power supply mode. Those applying this embodiment may also determine the current conversion efficiency of the power supply device <NUM> according to the intervals R2R and R3R to determine whether the status of the power supply device <NUM> is the load mode or the power supply mode. In other words, the processor <NUM> obtains the conversion efficiency point PR1 of the power supply device <NUM> and determines the current conversion efficiency of the power supply device <NUM> according to the conversion efficiency point PR1, so that the backup battery pack <NUM> performs switching to the charge mode or the discharge mode through the power converter <NUM>. Those applying this embodiment may also determine the current conversion efficiency of the power supply device <NUM> according to the intervals R2R and R3R, so that the backup battery pack <NUM> performs switching to the charge mode or the discharge mode through the power converter <NUM>.

To be specific, the processor <NUM> in <FIG> communicates with the computing server <NUM> to obtain the efficiency line from the computing server <NUM> and obtain the optimal conversion efficiency point PR1 of the power supply device <NUM>, and sets a preset load electricity characteristic value PVdc. The nature of the preset load electricity characteristic value PVdc may be a preset voltage value, electric current value, or resistance value. Those applying this embodiment may adjust the nature of the preset load electricity characteristic value depending on the requirements or the settings of the hardware circuit in the processor <NUM>. The preset load electricity characteristic value PVdc of this embodiment is a voltage value.

The processor <NUM> in <FIG> also obtains a current load electricity characteristic value from the power supply device <NUM>. In this embodiment, the power supply device <NUM> provides a current electric current value Imon corresponding to the load of the power supply device <NUM>, and the processor <NUM> in <FIG> obtains a current load electricity characteristic value Vimon of the power supply device <NUM> by the current electric current value Imon. The current load electricity characteristic value Vimon of this embodiment is a voltage value to be accordingly compared with the preset load electricity characteristic value PVdc. The processor <NUM> in <FIG> compares the preset load electricity characteristic value PVdc and the current load electricity characteristic value Vimon to determine the load of the power supply device <NUM> so as to determine whether the status of the backup power device <NUM> is the load mode or the power supply mode. In other words, the processor <NUM> in <FIG> compares the preset load electricity characteristic value PVdc and the current load electricity characteristic value Vimon to determine the load of the power supply device <NUM> so as to cause the backup battery pack <NUM> to perform switching to the charge mode or the discharge mode through the power converter <NUM>.

It is assumed here that when the power supply device <NUM> is at a load of <NUM>%, the current load electricity characteristic value Vimon is 8V and may be presented linearly. For example, a load of <NUM>% indicates that the load electricity characteristic value Vimon is <NUM>. Therefore, if it is intended to take a load of <NUM>% of the power supply device <NUM> as the basis for determining the load mode or the power supply mode of the backup power device <NUM>, the preset load electricity characteristic value PVdc is set to 4V.

<FIG> is a detailed circuit block diagram of the processor <NUM> in <FIG>. The processor <NUM> mainly includes a comparator <NUM>, a switching circuit <NUM>, and a pulse width modulation (PWM) controller <NUM>. The processor <NUM> also includes a delay circuit <NUM>. The comparator <NUM> and the switching circuit <NUM> are configured in a feedback controller <NUM> of the processor <NUM>. A first input terminal of the comparator <NUM> is configured to receive the preset load electricity characteristic value PVdc. A second input terminal of the comparator <NUM> is coupled to the power supply device <NUM> and configured to receive the current load electricity characteristic value Vimon of the power supply device <NUM>. An output terminal of the comparator <NUM> generates a comparison result <NUM> by comparing the voltage values of the current load electricity characteristic value Vimon and the preset load electricity characteristic value PVdc. An input terminal of the switching circuit <NUM> is coupled to the comparator <NUM> and configured to receive the comparison result <NUM> generated by the comparator <NUM>. The switching circuit <NUM> generates a switching signal S320 according to the comparison result <NUM>.

The PWM controller <NUM> is coupled to the switching circuit <NUM>, the charging converter <NUM>, and the discharging converter <NUM>. The PWM controller <NUM> generates at least one pulse signal to the charging converter <NUM> and the discharging converter <NUM> according to the switching signal S320, to thus selectively activate one of the charging converter <NUM> and the discharging converter <NUM>. When the charging converter <NUM> is operating (turned on), the discharging converter <NUM> is not operating (turned off). On the contrary, when the charging converter <NUM> is not operating (turned off), the discharging converter <NUM> is operating (turned on). In addition, those applying this embodiment may design so that the PWM controller <NUM> is indirectly coupled to the charging converter <NUM> and the discharging converter <NUM> through the delay circuit <NUM>, and the delay circuit <NUM> may be added according to the signal transmission between the PWM controller <NUM>, the charging converter <NUM>, and the discharging converter <NUM>, so as to adjust the current supply response speed on the power bus PBUS for signals to be transmitted smoothly.

<FIG> and <FIG> are respectively schematic diagrams of the power supply mode (i.e., the discharge mode of the backup battery pack <NUM>) and the load mode (i.e., the charge mode of the backup battery pack <NUM>) of the backup power device <NUM> corresponding to the power supply device <NUM> and the power bus PBUS according to an embodiment of the disclosure. For example, with reference to <FIG> and <FIG> together, it is known that the highest efficiency point PR1 is at a load of <NUM>% and the load of <NUM>% linearly corresponds to a load electricity characteristic value of <NUM>. 2V, then the preset load electricity characteristic value PVdc may be set to <NUM>. 2V, but not limited thereto. If the status of the backup power device <NUM> in <FIG> is the power supply mode (e.g., the power supply device <NUM> is at a load of <NUM>%), the current load electricity characteristic value Vimon of the power supply device <NUM> obtained by the processor <NUM> in <FIG> should be greater than 4V (here assumed to be linearly presented as <NUM>. 6V), the comparator <NUM> in the processor <NUM> generates the comparison result <NUM> corresponding to the power supply mode, and the switching circuit <NUM> also generates a comparison signal S320 corresponding to the power supply mode. In response to the power supply mode, the PWM controller <NUM> of the processor <NUM> controls the discharging converter <NUM> and disables the charging converter <NUM>, as shown in <FIG>, so that the backup battery pack <NUM> supplies power to the power bus PBUS (as indicated by arrow A3). The processor <NUM> in <FIG> causes the backup battery pack <NUM> to perform switching to the discharge mode through the power converter <NUM>. In other words, at this time, the backup battery pack <NUM> supplies power through the power bus PBUS, and the power of the backup battery pack <NUM> is converted by the discharging converter <NUM>. Since the power bus PBUS has the power provided by both the power supply device <NUM> and the backup battery pack <NUM> to the load (including the computing server <NUM>), the load of the power supply device <NUM> may accordingly be reduced from a load of <NUM>% to about <NUM>%, so that the load of the power supply device <NUM> is positioned at the optimal conversion efficiency point PR1 of <FIG>.

With reference to <FIG> and <FIG> together, for example, if the status of the backup power device <NUM> in <FIG> is the load mode (e.g., the power supply device <NUM> is at a load of <NUM>%), the current load electricity characteristic value Vimon of the power supply device <NUM> obtained by the processor <NUM> in <FIG> should be less than 4V (here assumed to be linearly presented as <NUM>. 8V), but not limited thereto. The comparator <NUM> in the processor <NUM> in <FIG> generates the comparison result <NUM> corresponding to the load mode, and the switching circuit <NUM> also generates the comparison signal <NUM> corresponding to the load mode. In response to the load mode, the processor <NUM> controls the charging converter <NUM> and disables the discharging converter <NUM>, as shown in <FIG>, the charging converter <NUM> converts the power of the power supply device <NUM>, and the backup battery pack <NUM> then receives the converted power by the charging converter <NUM> through the power bus PBUS to be charged (as indicated by arrow A2). The processor <NUM> in <FIG> causes the backup battery pack <NUM> to perform switching to the charge mode through the power converter <NUM>. Since the backup battery pack <NUM> is charged by a part of the power provided by the power supply device <NUM> to the power bus PBUS, while another part of the power provided by the power supply device <NUM> to the power bus PBUS is configured to supply power to the load (including the computing server <NUM>), which increases the power consumption of the power supply device <NUM>, the load of the power supply device <NUM> is increased from a load of <NUM>% to about <NUM>%, so that the load of the power supply device <NUM> is positioned at the optimal conversion efficiency point PR1 of <FIG>.

In particular, in response to the load mode and the backup battery pack <NUM> in the backup power device <NUM> in <FIG> being in a fully charged state, the processor <NUM> does not charge the backup battery pack <NUM> through the power bus PBUS, so as to prevent overcharging the backup battery units BBU in the backup battery pack <NUM>. In addition, in response to the power supply mode and the backup battery pack <NUM> in the backup power device <NUM> in <FIG> being in a state of low level charge (i.e., a state of low charge), the processor <NUM> does not discharge the power bus PBUS through the backup battery pack <NUM>, so as to prevent a low charge of the backup battery pack <NUM> being insufficient to provide adequate power energy to the computing server <NUM>.

<FIG> are line charts illustrating efficiencies of a plurality of power supply devices <NUM> according to an embodiment of the disclosure. Similar to <FIG>, for example, in <FIG>, a load of about <NUM>% is taken as the preset load electricity characteristic value, and it is accordingly determined whether the status of the backup power device is the load mode or the power supply mode. In addition, in <FIG>, a load of about <NUM>% is taken as the preset load electricity characteristic value, and it is accordingly determined whether the status of the backup power device is the load mode or the power supply mode. Nonetheless, the disclosure is not limited thereto. Therefore, those applying this embodiment may adjust the conversion efficiency point PR1 (e.g., a load of <NUM>% in <FIG> and a load of <NUM>% in <FIG>) as required. The optimal conversion efficiency interval for the power supply device <NUM> is not necessarily taken as the standard basis for the conversion efficiency point PR1.

<FIG> is a flowchart of a control method of a power supply system according to an embodiment of the disclosure. The control method is applied to the data center <NUM> of <FIG>. The data center <NUM> includes the power supply system <NUM>. The power supply system <NUM> includes the power supply device <NUM> and the backup power device <NUM>. The power supply system <NUM> is configured to supply power to a load. The load may include the at least one computing server <NUM>. In step S710, the processor <NUM> in <FIG> obtains a current conversion efficiency of the power supply device <NUM>. In step S720, the processor <NUM> in <FIG> determines whether a status of the backup power device <NUM> is a load mode or a power supply mode according to the current conversion efficiency of the power supply device <NUM>. In step S730, in response to the power supply mode, the processor <NUM> in <FIG> controls the backup battery pack <NUM> of the backup power device <NUM>, so that the backup power device <NUM> and the power supply device <NUM> simultaneously supply power to the computing server <NUM> of the data center <NUM>. In step S740, in response to the load mode, the processor <NUM> in <FIG> controls the backup power device <NUM> to be charged, so that the power supply device <NUM> charges the backup power device <NUM> while supplying power to the computing server <NUM> of the data center <NUM>. For the specific flows and details of the control method in <FIG>, reference may be made to the above embodiments.

Claim 1:
A power supply system (<NUM>) configured to supply power to a load, the power supply system (<NUM>) comprising:
a power supply device (<NUM>) supplying power to the load; and
a backup power device (<NUM>) comprising:
a backup battery pack (<NUM>);
a charging converter (<NUM>) coupled to the backup battery pack (<NUM>);
a discharging converter (<NUM>) coupled to the backup battery pack (<NUM>); and
a processor (<NUM>) coupled to the power supply device (<NUM>), the backup battery pack (<NUM>), the charging converter (<NUM>), and the discharging converter (<NUM>),
wherein the processor (<NUM>) is configured to determine whether a status of the backup power device (<NUM>) is a load mode or a power supply mode according to a current conversion efficiency of the power supply device (<NUM>), and
wherein in response to the status being the power supply mode, the processor (<NUM>) is configured to control the backup battery pack (<NUM>), such that the backup battery pack (<NUM>) and the power supply device (<NUM>) simultaneously supply power to the load.