Electric equipment with hybrid power supply device

Abstract

Disclosed is a hybrid power supply device for electric equipment or an electric tool. The hybrid power supply device is advantageously configured to operate in a number of different operating modes depending on the performance or power requirements of the equipment or tool and depending on whether AC power is available. In particular, the hybrid power supply device enables the equipment or tool to operate using AC power, battery power, or both. In addition, the hybrid power supply device enables charging of an attached battery and provides power to an AC accessory connected to the equipment or tool.

Description

Technical Field

[0001] The apparatus and method disclosed in this document relate to power supply devices, and more particularly, to a hybrid power supply device for electric equipment. Background Art

[0002] Unless otherwise indicated herein, the materials described in this section are not admitted to be prior art by inclusion in this section.

[0003] Conventional power tools and other power equipment include a variety of power sources depending on their specific requirements. For example, some equipment is battery-powered (i.e., cordless) and receives power via batteries, which are typically rechargeable or replaceable. Battery-powered equipment provides greater mobility and flexibility, but the operating time and maximum power output are limited by the capacity and output of the battery. For equipment that requires less mobility, power is typically received via a cord connected to a standard power outlet or other alternating current (AC) power source. Therefore, as long as the corded equipment is close enough to the AC power source, continuous power can be provided to the equipment. However, even corded equipment has a maximum power output, which can be implemented by a circuit breaker.

[0004] In situations where higher power and mobility are required, common alternatives to battery-powered equipment include gasoline-powered equipment that contains a small gasoline engine. Gasoline-powered equipment provides higher power while maintaining a certain level of mobility. In situations where very high power is required, common alternatives to fixed, wired equipment include pneumatic and hydraulic equipment. Such equipment is useful in heavy-duty and industrial applications. However, gasoline, pneumatic, and hydraulic equipment are generally more challenging to operate and more expensive to maintain than electrical equipment, especially for typical consumers and hobbyists.

[0005] There is a need for a power supply that provides easy use and maintenance of electrical equipment while providing the flexibility to be mobile when needed and to provide very high power when needed. Summary of the invention

[0006] A power supply device for a device is disclosed. The power supply device includes a first DC bus having a first direct current (DC) voltage. The device is configured to receive power from the first DC bus. The power supply device also includes a first power electronic device, which is configured to provide power from an alternating current (AC) power source to the first DC bus. The power supply device also includes a second DC bus having a second DC voltage. The second DC voltage is less than the first DC voltage. The power supply device also includes a second power electronic device, which is configured to provide power from the second DC bus to the first DC bus. The power supply device also includes a third power electronic device, which is configured to provide power from at least one battery pack to the second DC bus. The power supply device also includes a controller. The controller is configured to, in a first operating mode, operate the first power electronic device to provide power from the AC power source to the first DC bus. In the first operating mode, power is provided from the first DC bus to at least one load of the device. The controller is further configured to, in a second operating mode, operate the second power electronic device and the third power electronic device to provide power from the at least one battery pack to the first DC bus. In the second operating mode, power is provided from the first DC bus to at least one load of the device.

[0007] A further power supply device for a device is disclosed. The power supply device includes a DC bus having a first direct current (DC) voltage. The device is configured to receive power from the DC bus. The power supply device also includes a first power electronic device, the first power electronic device is configured to provide power to the DC bus from an alternating current (AC) power source. The power supply device includes a second power electronic device, the second power electronic device is configured to provide power to the DC bus from at least one battery pack. The power supply device includes a controller. The controller is configured to, in a first operating mode, operate the first power electronic device to provide power to the DC bus from the AC power source. In the first operating mode, power is provided from the DC bus to at least one load of the device. The controller is further configured to, in a second operating mode, operate the second power electronic device to provide power to the DC bus from the at least one battery pack, and in the second operating mode, power is provided from the DC bus to at least one load of the device.

[0008] A power tool is disclosed. The power tool includes an electric motor configured to drive the tool. The power tool also includes a DC bus having a direct current (DC) voltage. The electric motor is operably connected to receive power from the DC bus. The power tool also includes a first power electronic device, which is configured to provide power to the DC bus from an alternating current (AC) power source. The power tool also includes a second power electronic device, which is configured to provide power to the second DC bus from at least one battery pack. The power tool also includes a controller. The controller is configured to, in a first operating mode, operate the first power electronic device to provide power from the AC power source to the DC bus. In the first operating mode, power is provided to the electric motor from the DC bus. The controller is further configured to, in a second operating mode, operate the second power electronic device to provide power from the at least one battery pack to the DC bus. In the second operating mode, power is provided to the electric motor from the DC bus. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The foregoing aspects and other features of the hybrid power system are explained in the following description in conjunction with the accompanying drawings.

[0010] Figure 1 is a schematic diagram showing a piece of electric equipment having a hybrid power supply device.

[0011] Figure 2 is a schematic diagram illustrating the architecture of a hybrid power supply device.

[0012] Figure 3 is a schematic diagram illustrating an alternative architecture of a hybrid power supply device. DETAILED DESCRIPTION

[0013] In order to promote an understanding of the principles of the present disclosure, reference will now be made to the embodiments illustrated in the accompanying drawings and described in the following written specification. It should be understood that no limitation of the scope of the present disclosure is intended thereby. It should be further understood that the present disclosure includes any changes and modifications to the illustrated embodiments, and includes additional applications of the principles of the present disclosure as would normally occur to a person skilled in the art to which the present disclosure belongs.

[0014] Overview

[0015] Figure 1is a schematic diagram showing a piece of electric equipment 10 having a hybrid power supply device 20. In some embodiments, the electric equipment 10 may, for example, include a desktop power tool, such as a table saw, a band saw, a miter saw, a jigsaw, a drill press, a router table, a bench grinder, or a thickness planer. Likewise, the electric equipment 10 may also include equivalent and related handheld power tools. In other embodiments, the electric equipment 10 may, for example, include outdoor electric equipment, such as a lawn mower, a leaf blower, a snow blower, a chain saw, or a pressure washer. In at least some embodiments, the hybrid power supply device 20 is directly integrated with the electric equipment 10; however, in some embodiments, the hybrid power supply device 20 and the electric equipment 10 may also be provided separately and discretely.

[0016] The hybrid power supply device 20 is advantageously configured to operate in several different operating modes according to the performance or power requirements of the electric equipment and according to whether AC power is available. To this end, the electric equipment 10 and / or the hybrid power supply device 20 include one or more controllers for operating the power electronics of the hybrid power supply device 20. In one embodiment, a power supply controller 30 is provided as a main controller and is configured to select which (which) operating modes to operate the hybrid power supply device 20, and operate its power electronics according to the selected operating mode. Those of ordinary skill in the art will recognize that a "controller" includes any hardware system, hardware mechanism, or hardware component that processes data, signals, or other information. Therefore, the power supply controller 30 may include a system having a central processing unit, multiple processing units, a dedicated circuit system for implementing specific functions, or other systems.

[0017] In some embodiments, the electric equipment 10 further includes a physical user interface, such as one or more buttons or switches, via which a user can manually set an operating mode of the hybrid power device 20 .

[0018] In a first operating mode of the hybrid power supply device 20, power is provided to the electric equipment 10 from an alternating current (AC) power source 50 connected to the electric equipment 10, for example, via a power cord. In at least some embodiments, the AC power source 50 is a standard power outlet that provides an AC voltage between 110V and 230V at a frequency between 50-60Hz. However, the AC power source 50 may include any external system to which the electric equipment 10 can be connected to receive AC power, such as a gasoline generator or another alternative power source. It should be understood that the first operating mode has the advantage of providing continuous and relatively high power. In some embodiments, the power controller 30 is configured to automatically switch the hybrid power supply device 20 to the first operating mode in response to the electric equipment 10 being activated and the hybrid power supply device 20 being connected to the AC power source 50.

[0019] In the second operating mode of the hybrid power supply device 20, power is provided to the electric equipment 10 from at least one battery pack 40A, 40B, 40C. In at least some embodiments, each battery pack 40A-C is a rechargeable and discretely enclosed battery pack configured to be connected to the battery connection interface. In at least some embodiments, each battery pack 40A-C is removably connected to the electric equipment 10 via a battery connection interface (not shown). Each battery pack 40A-C is configured to provide a direct current (DC) voltage of, for example, 18V or 36V. In some embodiments, the hybrid power supply device 20 and the battery connection interface are configured to receive and operate with a battery pack providing a variety of different voltages and / or form factors. It should be understood that the second operating mode has the advantages of greater mobility and flexibility compared to the first operating mode in which a nearby AC power source is required, but has a limited operating time and power output. In some embodiments, the power controller 30 is configured to automatically switch the hybrid power supply device 20 to the second operating mode in response to the electric equipment 10 being activated and the hybrid power supply device 20 being disconnected from the AC power source 50. In at least some embodiments, in the second operating mode, the current drawn from each battery pack 40A-C is optimized based on load, battery capacity, battery temperature, etc., in order to maximize efficiency and thermal performance.

[0020] In the third operating mode of the hybrid power supply device 20, power is provided to the battery packs 40A-C from the AC power source 50 connected to the electric equipment 10, and the battery packs 40A-C are charged. It should be understood that when the electric equipment 10 is connected to the AC power source 50 but is not currently in use, the third operating mode can be effectively utilized to recharge the battery packs 40A-C. In some embodiments, the power controller 30 is configured to automatically switch the hybrid power supply device 20 to the third operating mode in response to the electric equipment 10 being deactivated (or otherwise not in use) while the hybrid power supply device 20 is connected to the AC power source 50. In some embodiments, the power controller 30 is configured to cause the battery packs 40A-C to be charged simultaneously, sequentially, or a combination of both, depending on the number of batteries connected to the system, the charge state of each battery, or the load current limit or load power limit associated with the AC power source 50, etc.

[0021] In the fourth operating mode of the hybrid power device 20, AC power is provided from the hybrid power device 20 (e.g., from the battery pack 40A-C and / or the AC power source 50) to an AC accessory 60 that is removably connected to the electric equipment 10. The AC accessory 60 can be any device that is configured to receive AC power and operate using AC power. In some embodiments, the AC accessory 60 can be, for example, a handheld power tool such as a drill, a saw, a router, or a sander. In some embodiments, the AC accessory 60 is connected to the electric equipment 10 and / or the hybrid power device 20 via a standard power socket (not shown) arranged on the housing of the electric equipment 10. It should be understood that the fourth operating mode has the following advantages: when there is no AC power source nearby, or when there is not a sufficient number of power sockets, AC power is provided from the electric equipment 10 to smaller accessory devices. In some embodiments, the power controller 30 is configured to automatically switch the hybrid power device 20 to the fourth operating mode in response to the hybrid power device 20 being connected to the AC accessory 60.

[0022] In the fifth operating mode of the hybrid power supply device 20, power is provided to the electric equipment 10 from both the AC power source 50 and the battery packs 40A-C. In this way, the electric equipment 10 can operate with the combined power output of the AC power source 50 and the battery packs 40A-C. It should be understood that the fifth operating mode is advantageous when the power or performance requirements of the electric equipment 10 exceed the load limit of the AC power source 50 alone (for example, the load will trip the circuit breaker or blow the fuse). In some embodiments, the power controller 30 is configured to automatically switch the hybrid power supply device 20 to the fifth operating mode in response to the hybrid power supply device 20 being connected to the AC power source 50 and the power requirements of the electric equipment 10 (for example, load current or load power) exceeding a predetermined threshold (for example, a load current limit or load power limit associated with the AC power source 50).

[0023] It should be understood that the operating modes of the hybrid power supply device 20 described herein do not necessarily need to be mutually exclusive. In some cases, the hybrid power supply device 20 is configured to operate in more than one operating mode at the same time. For example, in one embodiment, the hybrid power supply device 20 is configured so that it can operate in the first operating mode or the second operating mode to provide power to operate the electric equipment 10, while operating in the fourth operating mode to provide power to the AC accessories 60.

[0024] Hybrid power supply

[0025] Figure 2is a schematic diagram illustrating the architecture of a hybrid power supply device 20. The hybrid power supply device 20 includes a variety of power electronic devices configured to implement the functions described herein. Such power electronic devices may include an arrangement of several circuit components, such as relays, contactors, diodes, solid-state switches, resistors, capacitors, and inductors, which are not described in detail herein.

[0026] The hybrid power device 20 has a high-voltage DC bus 110 configured to distribute power to high-voltage loads in the electric equipment 10. As will be understood from the following description, the high-voltage DC bus 110 can receive power from the AC power source 50 or the battery packs 40A-C. In some embodiments, the high-voltage DC bus 110 has a nominal voltage of 400 volts.

[0027] In the illustrated embodiment, the high voltage load includes a high voltage brushless DC motor 120 of the electric equipment 10. In at least some embodiments, the high voltage brushless DC motor 120 is configured to drive a tool, such as a drill, a saw blade, or the like. The high voltage brushless DC motor 120 is operated by a high voltage motor driver 130, which has power electronics configured to receive power from the high voltage DC bus 110 and apply a suitable drive current to the high voltage brushless DC motor 120. It should be understood that the electric equipment 10 may include a variety of other high voltage loads.

[0028] The hybrid power supply device 20 also includes a power electronic device, in particular an AC / DC converter, configured to provide power from the AC power source 50 to the high-voltage DC bus 110. In at least some embodiments, this AC / DC converter is configured to act as a bidirectional AC / DC converter 140. In a converter or rectifier operating mode, the bidirectional AC / DC converter 140 is configured to provide power from the AC power source 50 to the high-voltage DC bus 110 by converting the AC voltage of the AC power source 50 to the nominal voltage of the high-voltage DC bus 110. In an inverter operating mode, the bidirectional AC / DC converter 140 is configured to provide power from the high-voltage DC bus 110 to the AC accessories 60 connected to the hybrid power supply device 20 by converting the nominal voltage of the high-voltage DC bus 110 from the high-voltage DC bus 110 to the AC voltage for the AC accessories 60. In at least one embodiment, the bidirectional AC / DC converter 140 has a totem pole power factor correction (PFC) topology.

[0029] The hybrid power device 20 also includes a low voltage DC bus 150. As will be understood from the following description, the low voltage DC bus 150 is an intermediate bus between the high voltage DC bus 110 and the battery packs 40A-C. In some embodiments, the nominal voltage of the low voltage DC bus 150 is less than the nominal voltage of the high voltage DC bus 110.

[0030] The hybrid power supply device 20 further includes a power electronic device, in particular a DC / DC converter, configured to provide power from the low-voltage DC bus 150 to the high-voltage DC bus 110. In at least some embodiments, this DC / DC converter is a bidirectional DC / DC converter 160. In a boost operation mode, the bidirectional DC / DC converter 160 is configured to provide power from the low-voltage DC bus 150 to the high-voltage DC bus 110 by converting the nominal voltage of the low-voltage DC bus 150 of the low-voltage DC bus 150 to the nominal voltage of the high-voltage DC bus 110 of the high-voltage DC bus 110. In a buck operation mode, the bidirectional DC / DC converter 160 is configured to provide power from the high-voltage DC bus 110 to the low-voltage DC bus 150 by converting the nominal voltage of the high-voltage DC bus 110 of the high-voltage DC bus 150 to the nominal voltage of the low-voltage DC bus 150 of the low-voltage DC bus 150. In at least one embodiment, the bidirectional DC / DC converter 160 is electrically isolated from the high-voltage DC bus 110 and the low-voltage DC bus 150, for example, by a transformer.

[0031] The hybrid power supply device 20 also includes power electronics, in particular, respective DC / DC converters, each of which is configured to provide power from a respective battery pack in the battery packs 40A-C to the low-voltage DC bus 150. In at least some embodiments, these DC / DC converters are bidirectional DC / DC converters 170A, 170B, 170C. In a discharge operation mode, the DC / DC converters 170A-C are configured to provide power from the battery packs 40A-C to the low-voltage DC bus 150 by converting the respective DC voltage (e.g., 18V or 36V) of the battery packs 40A-C to the nominal voltage of the low-voltage DC bus 150. In a charging operation mode, the DC / DC converters 170A-C are configured to provide power from the low-voltage DC bus 150 to the battery packs 40A-C by converting the nominal voltage of the low-voltage DC bus 150 to the DC voltage necessary to charge each of the respective battery packs 40A-C. In at least one embodiment, the DC / DC converters 170A-C are not electrically isolated.

[0032] exist Figure 3In an alternative embodiment shown in , the low voltage DC bus 150 is omitted from the hybrid power device 20. In this embodiment, the bidirectional DC / DC converters 170A, 170B, 170C are directly connected to the high voltage DC bus 110. Therefore, in the discharge operation mode, the DC / DC converters 170A-C are alternatively configured to provide power from the battery packs 40A-C to the high voltage DC bus 110 by converting the corresponding DC voltage (e.g., 18V or 36V) of the battery packs 40A-C to the nominal voltage of the high voltage DC bus 110. Likewise, in the charging operation mode, the DC / DC converters 170A-C are alternatively configured to provide power from the high voltage DC bus 110 to the battery packs 40A-C by converting the nominal voltage of the high voltage DC bus 110 to the DC voltage necessary to charge each of the corresponding battery packs 40A-C.

[0033] The power controller 30 is operably connected to the bidirectional AC / DC converter 140, the bidirectional DC / DC converter 160, and the DC / DC converters 170A-C, and is configured to operate these power electronic devices to achieve the first, second, third, fourth, and fifth operation modes of the hybrid power supply device 20. In some embodiments, the power controller 30 is a master controller, and the hybrid power supply device 20 includes a corresponding slave controller (not shown) associated with each of the bidirectional AC / DC converter 140, the bidirectional DC / DC converter 160, and the DC / DC converters 170A-C, and the power controller 30 commands the slave controllers to operate the bidirectional AC / DC converter 140, the bidirectional DC / DC converter 160, and the DC / DC converters 170A-C.

[0034] In the first operation mode, the power supply controller 30 is configured to operate the bidirectional AC / DC converter 140 to provide power from the AC power supply 50 to the high-voltage DC bus 110. In this first operation mode, power is provided from the AC power supply 50 to the load of the electric equipment 10 via the high-voltage DC bus 110. In particular, in some embodiments, an additional controller (not shown) is configured to operate the high-voltage motor driver 130 to drive the high-voltage motor 120 using power from the high-voltage DC bus 110.

[0035] In the second operation mode, the power supply controller 30 is configured to operate the DC / DC converter 160 and the DC / DC converters 170A-C to provide power from the battery packs 40A-C to the high-voltage DC bus 110. In this second operation mode, power is provided from the battery packs 40A-C to the load of the electric equipment 10 via the high-voltage DC bus 110. In particular, in some embodiments, an additional controller (not shown) is configured to operate the high-voltage motor driver 130 to drive the high-voltage motor 120 using power from the high-voltage DC bus 110.

[0036] In the third operating mode, the power controller 30 is configured to operate the bidirectional AC / DC converter 140 and the DC / DC converter 160 to provide power from the AC power source 50 to the low voltage DC bus 150. Additionally, in the third operating mode, the power controller 30 is configured to operate the DC / DC converters 170A-C to charge the battery packs 40A-C using power from the low voltage DC bus 150.

[0037] In the fourth operation mode, the power controller 30 is configured to operate the DC / DC converter 160 and the DC / DC converters 170A-C to provide power from the battery packs 40A-C to the high-voltage DC bus 110. In addition, in the fourth operation mode, the power controller 30 is configured to cause the bidirectional AC / DC converter 140 to act as a DC / AC inverter to provide AC power from the high-voltage DC bus 110 to the AC accessories 60 connected to the hybrid power supply device 20.

[0038] In the fifth operation mode, the power supply controller 30 is configured to operate the bidirectional AC / DC converter 140 to provide power from the AC power supply 50 to the high-voltage DC bus 110. At the same time, in the fifth operation mode, the power supply controller 30 is configured to operate the DC / DC converter 160 and the DC / DC converters 170A-C to provide power from the battery packs 40A-C to the high-voltage DC bus 110. In this fifth operation mode, power is provided to the load of the electric equipment 10 from both the AC power supply 50 and the battery packs 40A-C via the high-voltage DC bus 110. In particular, in some embodiments, an additional controller (not shown) is configured to operate the high-voltage motor driver 130 to drive the high-voltage motor 120 using power from the high-voltage DC bus 110.

[0039] Although the present disclosure has been illustrated and described in detail in the drawings and the foregoing description, the drawings and the foregoing description should be considered to be illustrative in nature and not restrictive. It should be understood that only preferred embodiments have been presented, and it is desired to protect all changes, modifications and other applications that fall within the spirit of the present disclosure.

Claims

1. A power supply device for a device, the power supply device comprising: a first direct current (DC) bus having a first DC voltage, the device being configured to receive power from the first DC bus; a first power electronic device configured to provide power to the first DC bus from an alternating current (AC) power source; a second DC bus having a second DC voltage, the second DC voltage being less than the first DC voltage; a second power electronic device configured to provide power from the second DC bus to the first DC bus; a third power electronic device configured to provide power from at least one battery pack to the second DC bus; as well as A controller, the controller being configured to: operating the first power electronic device to provide power from the AC power source to the first DC bus in a first operating mode, and providing power from the first DC bus to at least one load of the device in the first operating mode; as well as The second power electronic device and the third power electronic device are operated to provide power from the at least one battery pack to the first DC bus in a second operation mode, and power is provided from the first DC bus to at least one load of the device in the second operation mode. 2 . The power supply of claim 1 , wherein the controller is configured to automatically switch to the first operating mode in response to the device being activated while the power supply is connected to the AC power source. 3 . The power supply of claim 1 , wherein the controller is configured to automatically switch to the second operating mode in response to the device being activated while the power supply is disconnected from the AC power source.

4. The power supply device according to claim 1, wherein the controller is further configured to: In a third operating mode, (i) the first power electronic device and the second power electronic device are operated to provide power from the AC power source to the second DC bus; and (ii) the third power electronic device is operated to charge the at least one battery pack from the second DC bus. 5 . The power supply of claim 4 , wherein the controller is configured to automatically switch to the third operating mode in response to the device being deactivated while the power supply is connected to the AC power source.

6. The power supply device according to claim 1, wherein the controller is further configured to: In a fourth operating mode, (i) the second power electronic device and the third power electronic device are operated to provide power from the at least one battery pack to the first DC bus; and (ii) the first power electronic device is operated to provide AC power from the first DC bus to AC accessories connected to the power supply device. 7 . The power supply of claim 6 , wherein the controller is configured to automatically switch to the fourth operating mode in response to the power supply being connected to the AC accessory.

8. The power supply device of claim 6, wherein the AC accessory is a power tool.

9. The power supply device according to claim 1, wherein the controller is further configured to: In a fifth operating mode, (i) the first power electronic device is operated to provide power from the AC power source to the first DC bus; and (ii) the second power electronic device and the third power electronic device are operated to provide power from the at least one battery pack to the first DC bus, and in the fifth operating mode, power is provided from the first DC bus to at least one load of the device.

10. The power supply of claim 9, wherein the controller is configured to automatically switch to the fifth operating mode in response to the power requirement of the device exceeding a predetermined threshold when the power supply is connected to the AC power source.

11. The power supply device according to claim 1, wherein the power supply device is integrated with the device.

12. The power supply of claim 1, wherein the first DC bus provides power to an electric motor of the device.

13. The power supply according to claim 1, wherein the device is a power tool.

14. The power supply device according to claim 1, wherein the first power electronic device includes a bidirectional AC / DC converter, which is configured to: (i) provide power from the AC power supply to the first DC bus by converting the AC voltage of the AC power supply into the first DC voltage; and (ii) provide power from the first DC bus to AC accessories connected to the power supply device by converting the first DC voltage from the first DC bus into an AC voltage.

15. The power supply of claim 14, wherein the bidirectional AC / DC converter has a totem pole power factor correction topology.

16. The power supply device according to claim 1, wherein the second power electronic device includes a bidirectional DC / DC converter, and the bidirectional DC / DC converter is configured to: (i) provide power from the second DC bus to the first DC bus by converting the second DC voltage of the second DC bus into the first DC voltage of the first DC bus; and (ii) provide power from the first DC bus to the second DC bus by converting the first DC voltage of the first DC bus into the second DC voltage of the second DC bus. 17 . The power supply according to claim 16 , wherein the bidirectional DC / DC converter of the second power electronic device is electrically isolated from the first DC bus and the second DC bus.

18. A power supply device according to claim 1, wherein the third power electronic device includes at least one bidirectional DC / DC converter, and the at least one bidirectional DC / DC converter is configured to: (i) provide power from the at least one battery pack to the second DC bus by converting the DC voltage of the at least one battery pack into the second DC voltage of the second DC bus; and (ii) provide power from the second DC bus to the at least one battery pack by converting the second DC voltage of the second DC bus into the DC voltage of the at least one battery pack.

19. A power supply device for a device, the power supply device comprising: a direct current (DC) bus having a first DC voltage, the device being configured to receive power from the DC bus; a first power electronic device configured to provide power to the DC bus from an alternating current (AC) power source; a second power electronic device configured to provide power to the DC bus from at least one battery pack; as well as A controller, the controller being configured to: operating the first power electronic device to provide power from the AC power source to the DC bus in a first operating mode, and providing power from the DC bus to at least one load of the device in the first operating mode; as well as The second power electronic device is operated to provide power from the at least one battery pack to the DC bus in a second operating mode, and power is provided from the DC bus to at least one load of the device in the second operating mode.

20. An electric tool comprising: an electric motor configured to drive a tool; a direct current (DC) bus having a DC voltage, the electric motor being operably connected to receive power from the DC bus; a first power electronic device configured to provide power to the DC bus from an alternating current (AC) power source; a second power electronic device configured to provide power to the DC bus from at least one battery pack; as well as A controller, the controller being configured to: operating the first power electronics to provide power from the AC power source to the DC bus in a first operating mode, and providing power from the DC bus to the electric motor in the first operating mode; as well as The second power electronics are operated to provide power from the at least one battery pack to the DC bus in a second operating mode, and power is provided from the DC bus to the electric motor in the second operating mode.

Images