Patent Application
20130099574
Embodiments of the subject matter disclosed herein relate to energy storage systems. Other embodiments relate to uninterruptable power supplies.
1. Discussion of Art
Uninterruptable power supplies have battery systems that enable the uninterruptable power supply to provide power to a load when there is an interruption in a utility power grid or when there are quality issues with the incoming electrical supply. Current battery systems include dedicated battery systems for each uninterruptable power supply (UPS), for example, two uninterruptable power supplies, each of which has a battery system connected to it which serves only that uninterruptible power supply. Such systems are expensive and require UPS downtime when the batteries are serviced.
It would therefore be desirable to develop a system with battery system features and characteristics that differ from those of systems that are currently available.
2. Brief Description
In an embodiment, a system is provided having a single energy storage device, a first uninterruptable power supply switchably coupled to the single energy storage device, and at least one second uninterruptable power supply switchably coupled to the single energy storage device. As used herein, the term “single energy storage device” refers to an energy storage device that is electrically shared by two or more uninterruptible power supplies (UPS's), as opposed to each UPS having its own dedicated energy storage device; in at least one mode of operation, each UPS can potentially receive power from any part of the energy storage device. The system also comprises at least one disconnect switch assembly that includes at least two switches including a first switch (e.g., a dual pole switch) coupled to the first uninterruptable power supply, and a second switch (e.g., a dual pole switch) coupled to the second uninterruptable power supply. The at least one disconnect switch assembly is operatively connected externally and/or internally to the single energy storage device. Each switch has an on state and an off state to enable the energy storage device to electrically communicate with either or both uninterruptable power supplies (e.g., based on whether the switches are in the on state or off state). In another embodiment, the system further comprises a controller that is configured to control the at least one disconnect switch assembly and switching of the at least two switches between the on state and the off state, depending on the current mode of operation of the controller.
Another embodiment relates to a method. The method comprises a step of controlling at least one disconnect switch assembly to supply backup power from a single energy storage device to at least two uninterruptable power supplies, including a first uninterruptable power supply and a second uninterruptable power supply, over at least two electrical busses. In another embodiment, the method includes a step of controlling the at least two uninterruptable power supplies to supply input power from at least one alternating current feed to the single energy storage device and/or a load.
Reference is made to the accompanying drawings in which particular embodiments of the invention are illustrated as described in more detail in the description below, in which:
Embodiments relate to a system and method having a single energy storage system and multiple uninterruptable power supplies. With reference to the drawings, like reference numerals designate identical or corresponding parts throughout the several views. However, the inclusion of like elements in different views does not mean a given embodiment necessarily includes such elements or that all embodiments of the invention include such elements.
Further, the system 100 schematically illustrated in
As shown in
In the illustrated embodiment, the single energy storage device includes a first battery 146, a second battery 148, and a third battery 150 that are each switchably coupled to the first uninterruptable power supply 106 and the second uninterruptable power supply 122 via a dual bus configuration having a first electrical bus 111 and a second electrical bus 113. The first, second, and third batteries are connected in parallel and are switchably coupled to each uninterruptable power supply. The batteries in the single energy storage device may include, but are not limited to, at least one of the following electro-chemical storage technologies having electro-chemical cells: lead acid, sodium metal halide, lithium, and nickel-cadmium. Other types of electro-chemical technologies are possible as well. Further, the batteries may include any battery type, size, and energy capacity, including, but not limited to non-rechargeable and rechargeable batteries, e.g., a multi-cell battery, a 500 volt battery, 240 volt wet acid batteries, lithium-ion batteries, nickel metal hydride batteries, sodium-sulfur batteries, and the like. However, in general, every battery in a particular single parallel system embodiment (i.e., embodiment where multiple batteries are connected in parallel) operates at the same voltage and is typically of the same type and has the same number of cells as the other batteries in the system.
In accordance with an embodiment, the system 100 further includes at least one disconnect switch assembly for each battery or other energy source of the single energy storage device 142. In the illustrated embodiment, the first battery 146 is operatively connected to a first disconnect switch assembly 152 having a first switch 154 switchably coupled to the first uninterruptable power supply 106 and a second switch 156 switchably coupled to the second uninterruptable power supply 122, e.g., a dual disconnect switch assembly. Each switch is controllable (e.g., switchable) between an on state, for establishing one or more electrical connections, and an off state, for establishing one or more electrical open conditions. In accordance with an embodiment, each switch 154 and 156 is a two-pole switch providing the ability to switch in/out DC positive and negative potentials from the batteries (even though only a single line connection is shown in the figure). In the mode of operation shown in
In the illustrated embodiment, the switches of the disconnect switch assembly are contact switches. In another embodiment, the switches of the disconnect switch assembly are at least one of the following: a contact switch, a motor actuated switch, a motor actuated breaker, and/or a circuit breaker. Again, the switches are two-pole switches, in accordance with an embodiment. However, in accordance with an alternative embodiment, the switches may be single-pole switches, to connect/disconnect only the DC+ (positive) side or the DC− (negative) side of the battery.
Further in the illustrated embodiment, the second battery 148 is operatively connected to a second disconnect switch assembly 158 having a first switch 160 switchably coupled to the first uninterruptable power supply 106 and a second switch 162 switchably coupled to the second uninterruptable power supply 122. Furthermore, the third battery 150 is operatively connected to a third disconnect switch assembly 164 having a first switch 166 switchably coupled to the first uninterruptable power supply 106 and a second switch 168 switchably coupled to the second uninterruptable power supply 122. In the mode of operation shown in
In the illustrated embodiment, the first disconnect switch assembly 152, second disconnect switch assembly 158, and third disconnect switch assembly 164 are configured to be internal to a housing of the single energy storage device 142 that also includes the batteries, i.e., the housing houses the batteries and the disconnect switch assemblies. In another embodiment, the first disconnect switch assembly, the second disconnect switch assembly, and/or the third disconnect switch assembly may be configured to be located in another location, e.g., external to a housing of the single energy storage device.
In accordance with an embodiment, the system 100 further includes the controller 144 that is configured to monitor the system 100 for detection of operating events and configured to control each switch in the at least one disconnect switch assembly in response to the monitoring. For example, an operating event may include, but is not limited to, a battery source fault, an overheating battery, an uninterruptable power supply fault, an overheating uninterruptable power supply, a supply voltage fault, a disconnect switch assembly fault, and/or a load demand reduction. The controller 144 controls each switch of the disconnect switch assemblies and also controls when each switch electrically connects each battery to each uninterruptable power supply. In another embodiment, the controller may monitor the system or control the system based on input or output from another control system. In yet another embodiment, the system is configured to have two or more controllers that are each configured to be associated with at least one of the following: a disconnect switch assembly, an uninterruptable power supply, and/or a single energy storage device. In general, the controller can be implemented in a centralized manner or a distributed manner, in accordance with various embodiments of the present invention.
The controller is illustrated in
In accordance with an alternative embodiment, the controller 144 is not present in the system 100 and the disconnect switch assemblies are operated based on a local battery monitor of each battery. That is, a battery can disconnect itself from one or more of the uninterruptible power supplies via the corresponding disconnect switch assembly. A local battery monitor may monitor for certain types of internal battery faults and/or overheating conditions. For example, in battery 150, if a battery fault occurs or the battery overheats, a local battery monitor within the battery can send a signal to the disconnect switch assembly 164, commanding the switches 166 and 168 to open, disconnecting the battery 150 from each of the uninterruptible power supplies 122 and 106. In such an alternative embodiment, faults at other locations in the system 100 (other than battery-related faults) do not affect the disconnect switch assemblies. Such an alternative embodiment can be simpler and less costly than embodiments which include the controller 144.
Faults or degradation of the system 100 can occur at other points in the system 100 as well, and the controller 144 can monitor the system 100 and adapt the switch assemblies accordingly, in accordance with an embodiment. For example, a fault between the first uninterruptable power supply and the load or a fault between the second grid alternating current and the second uninterruptable power supply will cause the controller to electrically disconnect the corresponding switches in the switch assemblies.
In the illustrated embodiment, the first uninterruptable power supply 106 can disconnect (open connection) the first breaker 174 from the first electrical bus 111 when there is a major fault with the first uninterruptable power supply 106, e.g., a fault with the inverter or the rectifier. The first uninterruptable power supply 106 can activate the first breaker 174 to reconnect (closed connection) to the first electrical bus 111 when the fault condition clears or when the system is locally or remotely reset. For example, the first uninterruptable power supply 106 may control the first breaker 174 via an active/non-active signal that controls whether the first breaker 174 is connected (active) or disconnected (non-active) from the first electrical bus 111. Similarly, the second uninten-uptable power supply 122 can disconnect the second breaker 176 from the second electrical bus 113 when there is an overheating fault with the second uninterruptable power supply 122, for example. The second uninterruptable power supply 122 can also activate the second breaker 176 to reconnect to the second electrical bus 113 when the fault condition clears or when the system is locally or remotely reset. The second uninterruptable power supply 122 may control the second breaker 176 via an active/non-active signal that controls whether the second breaker 176 is connected or disconnected from the second electrical bus 113.
Furthermore, the system 100 illustrated in
By monitoring the uninterruptable power supplies and controlling operation of the transfer load switch, the decision support logic controller 180 is configured to balance the loading of the uninterruptable power supplies. For example, the controller 180 can select the uninterruptable power supply that has the most available capacity or may select the uninterruptable power supply that has the best quality power. In another embodiment, the controller can be configured to select or balance the uninterruptable power supplies by other parameters, e.g., type of uninterruptable power supply, type of AC connection and/or cost of electricity from the AC connection, or the like. In the illustrated embodiment, the transfer load switch 178 includes a first disconnect switch 182 and a second disconnect switch 184 that may be operatively controlled by the controller 180. For example, in the illustrated embodiment, the controller 180 may sense that the first uninterruptable power supply 106 is developing a number of minor faults that make the reliability of the power supply questionable, therefore, the controller 180 operatively disconnects the first uninterruptable power supply 106 by opening (disconnecting) the first disconnect switch 182. Therefore, the second uninterruptable power supply 122 is supplying power to load 108 through the second disconnect switch 184 shown in a closed (connected) position. In another embodiment, the system 100 illustrated in
In the illustrated embodiment, the switch 154 can be selectively controlled (manually or automatically) to connect or disconnect battery 146 to the first UPS disconnect switch 186 and the first uninterruptable power supply 106 and/or the second UPS disconnect switch 188 and the second uninterruptable power supply 122. In addition, the switch 160 can be selectively controlled to connect or disconnect battery 148 to the first UPS disconnect switch 186 and the first uninterruptable power supply 106 and/or the second UPS disconnect switch 188 and the second uninterruptable power supply 122. The switch 168 can be selectively controlled to connect or disconnect battery 148 to the first UPS disconnect switch 186 and the first uninterruptable power supply 106 and/or the second UPS disconnect switch 188 and the second uninterruptable power supply 122.
Embodiments of the invention utilize a single energy storage device for providing electrical power to plural uninterruptable power supplies. In one embodiment, a system comprises an energy storage device, a switch, a bus, and first and second uninterruptable power supplies. The switch is controllable to an on state (establishing an electrical connection) and an off state (establishing an electrical open condition, i.e., no electrical connection). The switch is operably connected to the bus between the uninterruptable power supplies and the energy storage device. When the switch is controlled to the on state, an electrical connection is established between the energy storage device and the uninterruptable power supplies over the bus. When the switch is controlled to the off state, there is no electrical connection between the energy storage device and the uninterruptable power supplies. In another embodiment, the system further includes a control element (controller, local monitor device(s), or the like) that is operably connected to the switch, for controlling the switch to the on state and the off state, depending on a current mode of operation of the system and/or based on one or more conditions of the system as monitored by the control element.
In another embodiment, a system comprises first and second batteries (e.g., connected in parallel), first and second switches, a bus, and first and second uninterruptable power supplies. Each switch is controllable to an on state (establishing an electrical connection) and an off state (establishing an electrical open condition). The first switch is operably connected to the bus between the uninterruptable power supplies and the first battery. The second switch is operably connected to the bus between the uninterruptable power supplies and the second battery. When the first switch is controlled to the on state, an electrical connection is established between the first battery and the uninterruptable power supplies over the bus. When the first switch is controlled to the off state, there is no electrical connection between the first battery and the uninterruptable power supplies. Similarly, when the second switch is controlled to the on state, an electrical connection is established between the second battery and the uninterruptable power supplies over the bus. When the second switch is controlled to the off state, there is no electrical connection between the second battery and the uninterruptable power supplies. In another embodiment, the system further includes a control element (controller, local monitor device(s), or the like) that is operably connected to the first and second switches, for controlling the switches to the on state and the off state, depending on a current mode of operation of the system and/or based on one or more conditions of the system monitored by the control element. In one mode of operation, both switches are in the on state, and both batteries are electrically connected to the uninterruptable power supplies. In a second mode of operation, one switch is in the on state, and the other switch is in the off state; thus, only one of the two batteries is electrically connected to the uninterruptable power supplies. In a third mode of operation, both switches are in the off state, and neither battery is electrically connected to the uninterruptable power supplies. In other embodiments, there are more than two batteries and more than two switches, with each battery having a switch associated therewith for controllably electrically connecting and disconnecting the battery from the bus and uninterruptable power supplies.
In another embodiment, a system comprises an energy storage device, first and second switches, first and second buses, and first and second uninterruptable power supplies. Each switch is controllable to an on state (establishing an electrical connection) and an off state (establishing an electrical open condition, i.e., no electrical connection). The first switch is operably connected to the first bus between the first uninterruptable power supply and the energy storage device. When the first switch is controlled to the on state, an electrical connection is established between the energy storage device and the first uninterruptable power supply over the first bus. When the first switch is controlled to the off state, there is no electrical connection between the energy storage device and the first uninterruptable power supply. The second switch is operably connected to the second bus between the second uninterruptable power supply and the energy storage device. When the second switch is controlled to the on state, an electrical connection is established between the energy storage device and the second uninterruptable power supply over the second bus. When the second switch is controlled to the off state, there is no electrical connection between the energy storage device and the second uninterruptable power supply. In another embodiment, the system further includes a control element (controller, local monitor device(s), or the like) that is operably connected to the switches, for controlling the switches to the on state and the off state, depending on a current mode of operation of the system and/or based on one or more conditions of the system as monitored by the control element. In one mode of operation, both switches are in the on state, and the energy storage device is electrically connected to both uninterruptable power supplies. In a second mode of operation, one switch is in the on state, and the other switch is in the off state; thus, the energy storage device is electrically connected to one of the uninterruptable power supplies only. In a third mode of operation, both switches are in the off state, and the energy storage device is electrically connected to neither of the uninterruptable power supplies.
In another embodiment, a system comprises first and second batteries, first, second, third, and fourth switches, first and second buses, and first and second uninterruptable power supplies. Each switch is controllable to an on state (establishing an electrical connection) and an off state (establishing an electrical open condition, i.e., no electrical connection). The first switch is operably connected to the first bus between the first uninterruptable power supply and the first battery. When the first switch is controlled to the on state, an electrical connection is established between the first battery and the first uninterruptable power supply over the first bus. When the first switch is controlled to the off state, there is no electrical connection between the first battery and the first uninterruptable power supply. The second switch is operably connected to the second bus between the second uninterruptable power supply and the first battery. When the second switch is controlled to the on state, an electrical connection is established between the first battery and the second uninterruptable power supply over the second bus. When the second switch is controlled to the off state, there is no electrical connection between the first battery and the second uninterruptable power supply. The third switch is operably connected to the first bus between the first uninterruptable power supply and the second battery. When the third switch is controlled to the on state, an electrical connection is established between the second battery and the first uninterruptable power supply over the first bus. When the third switch is controlled to the off state, there is no electrical connection between the second battery and the first uninterruptable power supply. The fourth switch is operably connected to the second bus between the second uninterruptable power supply and the second battery. When the fourth switch is controlled to the on state, an electrical connection is established between the second battery and the second uninterruptable power supply over the second bus. When the fourth switch is controlled to the of state, there is no electrical connection between the second battery and the second uninterruptable power supply.
In another embodiment, the system further includes a control element (controller, local monitor device(s), or the like) that is operably connected to the switches, for controlling the switches to the on state and the off state, depending on a current mode of operation of the system and/or based on one or more conditions of the system as monitored by the control element. In a first mode of operation (“all on” mode), all the switches are controlled to the on state, and both batteries are electrically connected to both uninterruptable power supplies. In a second mode of operation (“all off' mode), all the switches are controlled to the off state, and neither of the batteries is electrically connected to the uninterruptable power supplies. In a third mode of operation (”battery isolation” mode), the first and second switches are controlled to the on state, and the third and fourth switches are controlled to the off state. Here, the first battery is electrically connected to both uninterruptable power supplies, and the second battery is electrically connected to neither. (In a similar mode of operation, the third and fourth switches are controlled to the on state and the first and second switches to the off state, for the second battery to be electrically connected to both uninterruptable power supplies and the first battery to be electrically connected to neither.) In a fourth mode of operation (“UPS isolation” mode), the first and third switches are controlled to the on state, and the second and fourth switches are controlled to the off state. Here, both batteries are electrically connected to the first uninterruptable power supply, and neither battery is electrically connected to the second uninterruptable power supply. Similarly, the second and fourth switches may be controlled to the on state, and the first and third switches controlled to the off state. Here, both batteries are electrically connected to the second uninterruptable power supply, and neither battery is electrically connected to the first uninterruptable power supply.
Another embodiment relates to a system comprising first and second uninterruptable power supplies, first and second busses respectively electrically connected to the first and second uninterruptable power supplies, first and second batteries, and first and second disconnect switch assemblies. The first disconnect switch assembly is operably coupled between the first battery and the first and second busses, and the second disconnect switch assembly is operably coupled between the second battery and the first and second busses. (Each assembly may include two switches.) The first and second disconnect switch assemblies are controllable to: a first mode of operation where both batteries are electrically connected to both uninterruptable power supplies; a second mode of operation where neither battery is electrically connected to the uninterruptable power supplies; a third mode of operation where one of the batteries is electrically connected to both uninterruptable power supplies and the other battery is electrically connected to neither uninterruptable power supply; and a fourth mode of operation where both batteries are electrically connected to one of the uninterruptable power supplies only and not the other of the uninterruptable power supplies. In another embodiment, in the third mode of operation, the other battery (the one not connected to either UPS) is connected to no UPS's, and may be electrically isolated. In another embodiment, in the fourth mode of operation, the UPS that is not electrically connected to either battery is connected to no batteries or other energy sources, and thereby is electrically isolated at least from the energy sources/devices.
Another embodiment relates to a system comprising an energy storage device and two uninterruptable power supplies switchably coupled to the energy storage device via at least one electrical bus. The system further comprises at least one disconnect switch assembly operably coupled between the energy storage device and the at least one electrical bus. The at least one disconnect switch assembly is controllable to different modes of operation. In a first mode of operation of the at least one disconnect switch assembly, the energy storage device is electrically connected to neither of the two uninterruptable power supplies. In a second mode of operation of the at least one disconnect switch assembly, the energy storage device is electrically connected to both of the two uninterruptable power supplies such that both uninterruptable power supplies can receive power from all energy storage parts/components of the energy storage device. In a third mode of operation of the at least one disconnect switch assembly, the energy storage device is electrically connected to one of the two uninterruptable power supplies only and not to the other of the two uninterruptable power supplies. The system may further comprise a control element that is operably coupled to the at least one disconnect switch assembly for controlling the at least one disconnect switch assembly to the different modes of operation, e.g., automatically based on monitored operating conditions of the system, based on a control input, or based on a control scheme established by an operator.
In embodiments of the system having plural batteries or other energy storage elements, even if one of the batteries or other energy storage elements fails, the system is still able to provide electrical power to both/all uninterruptable power supplies, e.g., by controlling the switches/disconnect switch assembly(ies) to electrically isolate the failed energy storage element and electrically connect one or more of the healthy energy storage elements.
Although embodiments have been illustrated as the single energy storage device and disconnect switch assemblies being assembled as a single unit or package, in other embodiments, such components are not in the same unit or package, e.g., the batteries and disconnect switch assemblies may be separately housed but electrically connected together, as described above, using suitable wiring/cables.
In the appended claims, the terms “including” and “having” are used as the plain language equivalents of the terms “comprising”; the term “in which” is equivalent to “wherein.” Moreover, in the following claims, the terms “first,” “second,” “third,” “upper,” “lower,” “bottom,” “top,” etc. are used merely as labels, and are not intended to impose numerical or positional requirements on their objects. Further, the limitations of the following claims are not written in means-plus-function format and are not intended to be interpreted based on 35 U.S.C. §112, sixth paragraph, unless and until such claim limitations expressly use the phrase “means for” followed by a statement of function void of further structure. As used herein, an element or step recited in the singular and proceeded with the word “a” or “an” should be understood as not excluding plural of said elements or steps, unless such exclusion is explicitly stated. Furthermore, references to “one embodiment” of the present invention are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features. Moreover, unless explicitly stated to the contrary, embodiments “comprising,” “including,” or “having” an element or a plurality of elements having a particular property may include additional such elements not having that property. Moreover, certain embodiments may be shown as having like or similar elements, however, this is merely for illustration purposes, and such embodiments need not necessarily have the same elements unless specified in the claims.
As used herein, the terms “may” and “may be” indicate a possibility of an occurrence within a set of circumstances; a possession of a specified property, characteristic or function; and/or qualify another verb by expressing one or more of an ability, capability, or possibility associated with the qualified verb. Accordingly, usage of “may” and “may be” indicates that a modified term is apparently appropriate, capable, or suitable for an indicated capacity, function, or usage, while taking into account that in some circumstances the modified term may sometimes not be appropriate, capable, or suitable. For example, in some circumstances an event or capacity can be expected, while in other circumstances the event or capacity cannot occur—this distinction is captured by the terms “may” and “may be.”
This written description uses examples to disclose the invention, including the best mode, and also to enable one of ordinary skill in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differentiate from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.
