DEVICE FOR EXTRACTING A STATIC ELECTRIC CHARGE OF SUSPENSIVE PARTICLES IN AN ATMOSPHERE

Abstract

Device (201) for extracting a static electrical charge from suspended particles in an atmosphere, comprising: a first rechargeable energy storage device (203); and a charge conductor (211) that is exposed to the suspended particles in the atmosphere; characterized by the fact that the device (201) further comprises: a second rechargeable energy storage device (205) having a nominal voltage greater than that of the first rechargeable energy storage device (203); a DC-DC converter (209); and a first configuration state comprising a static discharge circuit, the charge conductor (211) being functionally coupled to a positive terminal of the first rechargeable energy storage device (203), a negative terminal of the first rechargeable energy storage device (203) being functionally coupled to a ground (223), and the static discharge circuit being functionally decoupled from the second rechargeable energy storage device (205), thereby recharging the first rechargeable energy storage device (203) by a charge flow through the static discharge circuit; and a second configuration state comprising the DC-DC converter (209) being functionally coupled between the first rechargeable energy storage device (203) and the second rechargeable energy storage device (205), thereby transferring energy from the first rechargeable energy storage device (203) to the second rechargeable energy storage device (205) via the DC-DC converter (209); wherein the second configuration state further comprises that the charge conductor (211) is functionally decoupled from the positive terminal of the first rechargeable energy storage device (203) and that the negative terminal of the first rechargeable energy storage device (203) is functionally decoupled from the ground mass (223).

Description

INTRODUCTION

[0001] The present invention relates to the extraction of energy from static electric charges of regolith on celestial bodies. In particular, the invention relates to a device according to the preamble of claim 1 for extracting a static electric charge from suspended particles in an atmosphere, as is known essentially from CN 1 08 260 268 A.

[0002] Further information on the state of the art can also be found in publications US 9,331,603 B2 and US 7,592,783 B1, as well as in the article entitled "Self-powered dust mitigation on the moon" by Choi, Sang H.; Moses, Robert W. (published in: Earth and Space 2021: Space Exploration, Utilization, Engineering, and Construction in Extreme Environments; Proceedings of the 17th Biennial International Conference on Engineering, Science, Construction, and Operations in Challenging Environments, Online 19-23 April 2021. Vol. 2. ASCE, 2021. pp. 791-800. ISBN 978-1-7138-3434-2).

[0003] Solar energy is the primary energy source for space exploration, providing renewable energy to recharge energy storage devices on spacecraft, vehicles, and stationary installations to power systems and instrumentation. While the availability of solar power on celestial bodies is predictable, it can be intermittent and essentially unavailable for extended periods. Therefore, alternative energy sources are desirable.

[0004] It is known that celestial bodies such as Earth's Moon and Mars have atmospheres that carry suspended clouds or plumes of regolith. The regolith suspension is at least partially a consequence of the static charge of the regolith particles. Regolith presents a challenging environmental condition because it can be damaging to exposed surfaces, including astronauts' spacesuits, is difficult to remove from surfaces, is a respiratory irritant for astronauts, and can pose risks due to charge levels that can approach several thousand volts. Therefore, avoiding or mitigating regolith within the operational areas of a space mission is desirable. SUMMARY

[0005] According to the invention, a device with the features of claim 1 for removing a static electrical charge from suspended particles in an atmosphere is presented.

[0006] Furthermore, a method for extracting a static electric charge from suspended particles in an atmosphere is described, which may include exposing a charge conductor to the suspended particles in the atmosphere and optionally providing a conductive path between the charge conductor and a ground mass, wherein the conductive path includes a rechargeable energy storage device coupled between the charge conductor and the ground mass, and wherein the rechargeable energy storage device is recharged by a charge flow via the conductive path.

[0007] In addition to one or more of the features described here, energy stored within the rechargeable energy storage device can optionally be transferred to another rechargeable energy storage device.

[0008] In addition to one or more of the features described here, the optional transfer of energy stored within the rechargeable energy storage device may include the use of a DC-DC converter to transfer charge from the rechargeable energy storage device to the other rechargeable energy storage device.

[0009] In addition to one or more of the features described here, the land mass may contain a celestial body outside the Earth's atmosphere.

[0010] In addition to one or more of the features described here, the fact that the charge conductor is exposed to the suspended particles in the atmosphere may include the movement of the charge conductor by the suspended particles in the atmosphere.

[0011] In addition to one or more of the features described here, the load conductor may be attached to a ground vehicle and the movement of the load conductor by the suspended particles in the atmosphere may include the movement of the ground vehicle.

[0012] In addition to one or more of the features described herein, the device according to the invention may further include a third configuration state in which the first rechargeable energy storage device, the second rechargeable energy storage device, the DC-DC converter, the charge conductor and the ground mass are functionally decoupled from each other.

[0013] In addition to one or more of the features described here, the first rechargeable energy storage device of the device according to the invention can be a lithium-ion battery.

[0014] In addition to one or more of the features described herein, the first rechargeable energy storage device of the device according to the invention may include a capacitor.

[0015] In addition to one or more of the features described herein, the device according to the invention may further include a ground vehicle, wherein the first rechargeable energy storage device, the second rechargeable energy storage device and the charge conductor are carried on the vehicle.

[0016] In addition to one or more of the features described herein, the device according to the invention may further include at least one switch which is operable to selectively establish the first configuration state.

[0017] In addition to one or more of the features described herein, the device according to the invention may further include several switches which are operable to selectively establish the first configuration state, the second configuration state and the third configuration state.

[0018] Furthermore, an electrified vehicle is described. The vehicle can include a first rechargeable energy storage device, an electric propulsion system comprising a second rechargeable energy storage device and an electric motor, a charge conductor exposed to statically charged particles in an atmosphere, a DC-DC converter, several controllable switches, and a controller functionally coupled to the multiple switches to establish a first configuration state containing a static discharge circuit. The charge conductor is functionally coupled to a positive terminal of the first rechargeable energy storage device, a negative terminal of the first rechargeable energy storage device is functionally coupled to a ground mass, and the static discharge circuit is functionally decoupled from the second rechargeable energy storage device.wherein the first rechargeable energy storage device is recharged by a charge flow through the static discharge circuit, and wherein the controller is functionally coupled with the multiple switches to establish a second configuration state which includes the DC-DC converter being functionally coupled between the first rechargeable energy storage device and the second rechargeable energy storage device, thereby transferring energy from the first rechargeable energy storage device to the second rechargeable energy storage device via the DC-DC converter.

[0019] In addition to one or more of the features described here, the load conductor may include a vehicle radiator.

[0020] In addition to one or more of the features described here, the charge conductor may include a solar panel of the vehicle.

[0021] In addition to one or more of the features described here, the load conductor may include a robotic arm of the vehicle.

[0022] In addition to one or more of the features described here, the first rechargeable energy storage device can be detachably attached to the vehicle.

[0023] The above features and advantages, and further features and advantages of the invention, will become readily apparent from the following detailed description when taken together with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Further features, advantages and details appear only as examples in the following detailed description, which refers to the drawings; they show: Fig. 1 an electrified ground vehicle according to one or more embodiments; and Fig.2 a device for removing a static electric charge according to one or more embodiments. DETAILED DESCRIPTION

[0025] The following description is essentially only exemplary. Corresponding reference symbols throughout the drawings denote identical or corresponding parts and features.

[0026] Fig.Figure 1 schematically represents an embodiment of an electrified vehicle 101. The vehicle 101 may include a chassis 103 or another mechanical structure for mounting and supporting vehicle systems and a device containing, for example, powertrain components, chassis components, and other components according to the vehicle's application purposes. According to one embodiment, the vehicle 101 may be a ground vehicle equipped for driving over solid ground in space exploration applications on celestial bodies such as the Moon, Mars, other planets within or outside the Earth's solar system and its moons or asteroids. As used here, a celestial body means any natural object outside the Earth's atmosphere. The vehicle 101 may have an electric propulsion system comprising wheels 105 driven by one or more traction motors 150.The vehicle may include a primary rechargeable energy storage device (RESD) 110, which provides electrical power for vehicle systems and components such as the traction motor 150, radio communication equipment, computer-aided controllers (controllers) 155, power electronics, and actuators. As part of a thermal management system carried by the vehicle 101, the vehicle 101 may include a radiator 120. The vehicle 101 may include a solar panel 130 for converting light energy into electrical energy that can be used to recharge the primary RESD 110. The vehicle 101 may include a robotic arm 140 for performing useful tasks on and around the vehicle 101.

[0027] For example, it is known that the surface of Earth's moon is covered in fine lunar dust, or regolith, and that the regolith can float in the atmosphere due to the static charge of its particles. Regolith presents a challenging environmental condition because it can damage exposed surfaces, including astronaut spacesuits, is difficult to remove from surfaces, is a respiratory irritant for astronauts, and can pose risks due to charge levels that can approach several thousand volts. Vehicle 101 can be configured to extract static electrical charge from the atmosphere surrounding the celestial bodies on which Vehicle 101 is deployed, and in the process also mitigate some of the adverse effects of regolith, such as rising, sticking, and high charge levels.Thus, a device capable of extracting the static charge from suspended particles can be advantageously used to supplement the energy of solar panels or as a primary energy source when solar energy is unavailable, for example, during lunar nights, which have a duration of essentially 14 Earth days. Advantageously, such charge extraction can be used to improve local conditions within an area where this extraction is performed. Mobile systems assigned to Vehicle 101 can be capable of reducing suspended charged regolith to prepare platform areas for spacecraft landings, to clean areas after a spacecraft landing, or to otherwise prepare areas for manual work and tasks.Thus, according to one embodiment, the vehicle 101 can further include an electrical charge conductor (conductor) 145 for exposing it to the suspended particles of the regolith in the atmosphere, and an additional RESD 115 for storing the energy from the static electrical charge. According to one embodiment, the additional RESD 115 can be detachable from the vehicle 101 for use as an electrical power supply remotely from the vehicle. According to one embodiment, the vehicle 101 can further include a DC-DC converter 125, which is functionally controllable for transferring energy from the additional RESD 115 to the primary RESD 110. According to one embodiment, the vehicle can include at least one controllable functional switch (switch) 135 for configuring a circuit for static discharge, optionally via the additional RESD 115, to recharge the additional RESD 115. A switch such as the one used here can, for example,physical contact devices such as relays or solid-state switches such as solid-state relays or transistors are included.

[0028] The DC-DC converter 125 and at least one switch can be used to connect one or more controllers 155 for signaling and functional control. As used here, terms such as control module, module, control system, controller, control unit, electronic control unit, processor, and similar terms refer to any combination of one or more application-specific integrated circuits (ASICs), electronic circuits, central processing units (preferably microprocessors), and associated memory and storage (read-only memory (ROM), read / write memory (RAM), electrically programmable read-only memory (EPROM), hard disk drive, etc.).) or from microcontrollers executing one or more software or firmware programs or software or firmware routines, combination logic circuits, input / output (I / O) circuit arrangements and I / O devices, suitable signal conditioning and buffering circuit arrangements, a fast clock, analog-to-digital (A / D) and digital-to-analog (D / A) circuit arrangements, and other components to provide the described functionality. A control module may include a variety of communication interfaces, including point-to-point or discrete lines and wired or wireless interfaces to networks, including wide area networks, local area networks, and factory and customer service networks, including for over-the-air (OTA) software updates.The functions of the control module as described in this invention can be executed in a distributed control architecture among multiple networked control modules. Software, firmware, programs, instructions, routines, code, algorithms, and similar terms mean any set of instructions executable by a controller, including calibrations, data structures, and lookup tables. A control module may comprise a set of control routines that are executed to provide the described functions. Routines are executed, as if by a central processing unit, and can be operated to monitor inputs from sensing devices and other networked control modules, and to execute control and diagnostic routines for controlling the operation of actuators. Routines can be executed at regular intervals during continuous power machine and vehicle operation.Alternatively, routines can be executed in response to the occurrence of an event, to software calls, or, if required, via user interface inputs or user interface requests.

[0029] According to one embodiment, the at least one switch 135 can contain several switches in order to, as indicated by the dashed lines in Fig.As shown in Figure 1, a variety of configurations can be achieved between the primary RESD 110, the auxiliary RESD 115, the conductor 145, and the DC-DC converter 125. As used here, rechargeable energy storage device can refer to an electrochemical cell or battery of electrochemical cells (battery), a capacitor, or any other device capable of absorbing electrical energy for storage and subsequent release. Cells and batteries can have any suitable electrochemical topology, including, for example, lithium-ion cells with liquid, polymer, solid, or hybrid solid electrolytes.According to one embodiment, the conductor 145 can be a dedicated, single-purpose device such as one or more conductive rods, a conductive plate, a skin, a coating, a film, a screen, a paint application, deposits, or traces on or carried by the vehicle 101 or components thereof. According to another embodiment, the conductor 145 can be integrated into or on components or features of the vehicle 101, e.g., the chassis 103, the radiator 120, the solar panel 130, or the robot arm 140.

[0030] Based on Fig. Figure 2 shows an embodiment of a device 201 for extracting a static electric charge. The device 201 can be part of a ground vehicle 101, as is the case here in connection with Fig.as described in section 1, although it can alternatively be a stationary system. The device 201 can be a first RESD 203, such as an additional RESD 115, and a second RESD 205, such as a primary RESD 110, which are described here in connection with Fig. The devices described in Section 1 are included. According to one embodiment, the second RESD 205 can provide electrical power for a DC bus 207 to power various systems. According to one embodiment, the first RESD 203 can have a nominal voltage that is lower than the nominal voltage of the second RESD 205. According to alternative embodiments, the first RESD 203 can have a nominal voltage that is lower than or equivalent to the nominal voltage of the second RESD 205. Furthermore, the device 201 can include a conductor for electrical charge (conductor) 211, which is exposed to the atmosphere and, in particular, to statically charged suspended particles of regolith 212. In addition to those described here in connection with Fig.In the ladder configurations described in Section 1 for vehicle application, the ladder 211 in a stationary installation can be part of, or be supported by, any suitable structure, including a building, housing, frame, spacecraft, mast, and the like. Advantageously, moving the ladder 211 through the regolith can enable extended charge collection areas in either mobile or stationary installations. For example, a movable ladder in a stationary installation can effect charge collection in an area surrounding the stationary installation. Likewise, a ladder carried on a ground vehicle 101 can be exposed to regolith over a much larger area, in accordance with the range of movement and the operating range of the vehicle.According to one embodiment, at least one switch can be provided to selectively configure a static discharge circuit that includes the conductor 211, which is coupled to the positive terminal of the first RESD 203, and the negative terminal of the first RESD 203, which is coupled to ground 223. In such a basic configuration, the at least one switch can complete the static discharge circuit via the first RESD 203 by coupling the negative terminal of the first RESD 203 to ground 223 (e.g., by switch 217), wherein the positive terminal of the first RESD 203 is directly coupled to the conductor 211. Alternatively, in such a basic configuration, the at least one switch can couple the positive terminal of the first RESD 203 to the conductor 211 (e.g., by switch 215), wherein ground 223 is directly coupled to the negative terminal of the first RESD 203.The recharging of the first RESD 203 is effected by selectively actuating the at least one switch to complete the conductive path, which is the circuit for static discharge to allow charge to flow through the first RESD 203. Ground ground, as used here, means a "grounding ground" to the solid ground 225 of the celestial body on which the device 201 is deployed, e.g., the lunar surface of the Moon. A ground ground can be established, for example, in stationary installations by a conductive post embedded in the solid ground, or in vehicle applications by a conductive rake in contact with the solid ground. According to one embodiment of a vehicle application in which the vehicle chassis provides a ground of the electrical system to the negative terminals of the first RESD 203 and the second RESD 205, the ground ground 223 can be established by grounding the chassis.

[0031] According to one embodiment, the at least one switch can be several controllable functional switches (switches) 213, and the device 201 can further include a DC-DC converter 209 to enable and effect energy transfer from the first RESD 203 to the second RESD 205 by establishing a number of configurations between the first RESD 203, the second RESD 205, the conductor 211, the ground 223, and the DC-DC converter. According to one embodiment, the switch 215 can be a three-state switch comprising a first closed state (1), which couples the positive terminal of the first RESD 203 to the conductor 211, a second closed state (2), which couples the positive terminal of the first RESD 203 to the input stage of the DC-DC converter 209, and an open state (0).According to one embodiment, the switch 217 can be a three-state switch comprising a first closed state (1) that couples the negative terminal of the first RESD 203 to ground 223, a second closed state (2) that couples the negative terminal of the first RESD 203 to the negative terminal of the second RESD 205, and an open state (O). According to one embodiment, the switch 219 can be a two-state switch comprising a closed state (C) that couples the output stage of the DC-DC converter 209 to the positive terminal of the second RESD 205, and an open state (O). According to one embodiment, the switch 221 can be a two-state switch comprising a closed state (C) that couples the ground of the DC-DC converter 209 to the negative terminal of the first RESD 205, and an open state (O).

[0032] According to one embodiment, the DC-DC converter 209 can operate in a boost mode in which the nominal voltage of the first RESD 203 is lower than the nominal voltage of the second RESD 205. According to another embodiment, the DC-DC converter 209 can operate in a buck mode in which the nominal voltage of the first RESD 203 is higher than the nominal voltage of the second RESD 205. It is understood that, according to an embodiment in which the first RESD 203 has a nominal voltage higher than the nominal voltage of the second RESD 205, sufficient to transfer energy from the first RESD 203 to the second RESD 205, a DC-DC converter may be optional. However, according to an embodiment that utilizes a DC-DC converter to transfer energy from the first RESD 203 to the second RESD 205, the DC-DC converter advantageously provides a voltage regulation function.According to an embodiment that does not use a DC-DC converter 209, the switch 221 can be omitted and the switches 215 and 219 can be directly coupled without an intermediate DC-DC converter 209.

[0033] State Table 1 presents the switch states of switches 215, 217, 219, and 221 for establishing three configuration states of the device 201 as described herein. A first configuration state includes a static discharge circuit in which conductor 211 is functionally coupled to the positive terminal of the first RESD 203, the negative terminal of the first rechargeable energy storage device 203 is functionally coupled to ground, and the static discharge circuit is functionally decoupled from the second RESD 205, thereby recharging the first RESD 203 by a charge flow through the static discharge circuit. The first configuration state can be established by switch 215 in the first closed state (1), by switch 217 in the first closed state (1), by switch 219 in the open state (O), and by switch 221 in the open state (O).A second configuration state involves the DC-DC converter 209 being functionally coupled between the first RESD 203 and the second RESD 205, thereby transferring energy from the first RESD 203 to the second RESD 205 via the DC-DC converter 209. This second configuration state can be achieved by having switch 215 in the second closed state (2), switch 217 in the second closed state (2), switch 219 in the closed state (C), and switch 221 in the closed state (C). According to one embodiment of the second configuration state, the circuit for static discharge can remain functional, for example, with alternative or additional switches to switches 215 and 217. A third configuration state includes the fact that the first RESD 203, the second RESD 205, the DC-DC converter 209, the conductor 211 and the ground 223 are functionally decoupled from each other.The third configuration state can be established by having switch 215 in the open state (O), switch 217 in the open state (O), switch 219 in the open state (O), and switch 221 in the open state (O). Condition table 1 Switch 215 Switch 217 Switch 219 Switch 221 1 2 open 1 2 open open closed open closed Configuration state 1 X X X X Configuration state 2 X X X X Configuration state 3 X X X X

Claims

[1] Device (201) for extracting a static electrical charge from suspended particles in an atmosphere, comprising: a first rechargeable energy storage device (203); and a charge conductor (211) that is exposed to the suspended particles in the atmosphere; characterized by , that the device (201) further comprises: a second rechargeable energy storage device (205) having a nominal voltage greater than that of the first rechargeable energy storage device (203); a DC-DC converter (209); and a first configuration state comprising a static discharge circuit, the charge conductor (211) being functionally coupled to a positive terminal of the first rechargeable energy storage device (203), a negative terminal of the first rechargeable energy storage device (203) being functionally coupled to a ground (223), and the static discharge circuit being functionally decoupled from the second rechargeable energy storage device (205), thereby recharging the first rechargeable energy storage device (203) by a charge flow through the static discharge circuit; and a second configuration state comprising the DC-DC converter (209) being functionally coupled between the first rechargeable energy storage device (203) and the second rechargeable energy storage device (205), thereby transferring energy from the first rechargeable energy storage device (203) to the second rechargeable energy storage device (205) via the DC-DC converter (209); wherein the second configuration state further comprises that the charge conductor (211) is functionally decoupled from the positive terminal of the first rechargeable energy storage device (203) and that the negative terminal of the first rechargeable energy storage device (203) is functionally decoupled from the ground mass (223). [2] Device (201) according to claim 1, further comprising a third configuration state comprising the first rechargeable energy storage device (203), the second rechargeable energy storage device (205), the DC-DC converter (209), the charge conductor (211) and the base mass (223) being functionally decoupled from each other.

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