WO2019157994A1

WO2019157994A1 - Switchgear units for electrical power distribution systems

Info

Publication number: WO2019157994A1
Application number: PCT/CN2019/074475
Authority: WO
Inventors: Xuhui REN; Junjia SHEN; Yu Lu
Original assignee: Industrial Connections & Solutions LLC
Priority date: 2018-02-13
Filing date: 2019-02-01
Publication date: 2019-08-22
Also published as: CN110165597A

Abstract

A switchgear unit for use in an electrical power distribution system includes a breaker compartment containing a circuit breaker and a rack assembly coupled to the circuit breaker. The rack assembly is operable to move the circuit breaker between a first position and a second position within the breaker compartment. The switchgear unit further includes a switch device operable to selectively electrically isolate the circuit breaker and a motor assembly. The motor assembly includes a motor, and a rack transmission coupled between the motor and the rack assembly. The motor assembly also includes a switch transmission coupled between the motor and the switch device, the motor operable to drive the rack transmission to move the circuit breaker using the rack assembly, the motor further operable to drive the switch transmission to selectively electrically isolate the circuit breaker using the switch device.

Description

SWITCHGEAR UNITS FOR ELECTRICAL POWER DISTRIBUTION SYSTEMS

BACKGROUND

The present application relates generally to electrical power distribution systems and, more particularly, to switchgear units for electrical power distribution systems.

At least some known electrical power distribution systems include a plurality of switchgear units including circuit breakers that are coupled to one or more loads. The circuit breakers are configured to interrupt current to the loads ifthe current is outside of acceptable conditions.

At least some known switchgear units are arranged to house multiple circuit breakers therein. Further, at least some of these switchgear units use an air insulated connection between circuit breakers and bus bar assemblies positioned within switchgear units. However, air insulated connections require a relatively large amount of space to allow sufficient air insulation within the connections and can result in relatively large switchgear units. Furthermore, at least some other methods of insulating circuit breaker connections with bus bar assemblies can have the effect of overheating the bus bar assemblies. Additionally, at least some switchgear units generally connect circuit breakers to bus bar assemblies through a manually operated hand crank that moves the circuit breaker to a connection point. However, manually operated connection mechanisms generally do not provide a high level of consistency between connections as they are subject to variance in operator control. While this may generally be acceptable for air insulated connections, other types of connections that require less space can suffer from a lack of consistency in connecting circuit breakers to bus bar assemblies. For example, an inconsistent or bumpy connection for a sealed connection can result in a failure of the sealing.

Accordingly, a need exists for more compact switchgear units for electrical distribution systems that require less manual operator control and allow for a greater stability in connecting circuit breakers to bus bar assemblies.

BRIEF DESCRIPTION

In one aspect, a switchgear unit for use in an electrical power distribution system is provided. The switchgear unit includes a breaker compartment containing a circuit breaker and a rack assembly coupled to the circuit breaker. The rack assembly is operable to move the circuit breaker between a first position and a second position within the breaker compartment. The switchgear unit further includes a switch device operable to selectively electrically isolate the circuit breaker and a motor assembly. The motor assembly includes a motor, and a rack transmission coupled between the motor and the rack assembly. The motor assembly also includes a switch transmission coupled between the motor and the switch device, the motor is operable to drive the rack transmission to move the circuit breaker using the rack assembly, the motor is further operable to drive the switch transmission to selectively electrically isolate the circuit breaker using the switch device.

In another aspect, a motor assembly for controlling a rack assembly and a switch device of a switchgear unit is provided. The motor assembly includes a motor, and a rack transmission coupled between the motor and the rack assembly. The motor assembly also includes a switch transmission coupled between the motor and the switch device. The motor is operable to drive the rack transmission to move the circuit breaker using the rack assembly. The motor is further operable to drive the switch transmission to selectively electrically isolate the circuit breaker using the switch device.

In yet another aspect, a method of using an electrical distribution system is provided. The method includes positioning a circuit breaker within a breaker compartment of a switchgear unit and coupling a rack assembly to the circuit breaker. The rack assembly is operable to move the circuit breaker between a first position and a second position within the breaker compartment. The method further includes coupling a switch device within the switchgear unit, the switch device operable to selectively electrically isolate the circuit breaker. The method further includes coupling a motor assembly to the rack assembly and the switch device, the motor assembly including a motor, arack transmission coupled between the motor and the rack assembly, and a switch transmission coupled between the motor and the switch device. The motor is operable to drive the rack transmission to move the circuit breaker using the rack assembly. The motor is further operable to drive the switch transmission to selectively electrically isolate the circuit breaker using the switch device.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of an exemplary electrical power distribution system;

FIG. 2 is an enlarged view of the bus bar assembly and load connection members of the switchgear unit shown in FIG. 1;

FIG. 3A is an enlarged view of the switchgear unit shown in FIG. 1, in which the motor assembly is coupled to the switch device and the rack assembly;

FIG. 3B is a bottom view of the motor assembly shown in FIG. 3A;

FIG. 3C is a front view of a portion of the rack transmission shown in FIG. 3A;

FIG. 4A is a side view of the rack assembly shown in FIGS. 3A-C including a first circuit breaker and in which the rack screw is not positioned within the socket;

FIG. 4B is a side view of the rack assembly shown in FIG. 4A including the first circuit breaker positioned at an entry point and in which the rack screw is positioned within the socket;

FIG. 4C is a side view of the rack assembly shown in FIG. 4B including the first circuit breaker positioned at the connection point;

FIG. 5A is a side view of a portion of the switch device shown in FIG. 3A in the open position;

FIG. 5B is a side view of a portion of the switch device shown in FIG. 3A in the closed position; and

FIG. 6 is a side view of an electrical power distribution system including a modular switchgear unit.

Although specific features of various embodiments may be shown in some drawings and not in others, this is for convenience only. Any feature of any drawing may be referenced and/or claimed in combination with any feature of any other drawing.

DETAILED DESCRIPTION

In the following specification and the claims, reference will be made to a number of terms, which shall be defined to have the following meanings.

The singular forms “a” , “an” , and “the” include plural references unless the context clearly dictates otherwise.

“Optional” or “optionally” means that the subsequently described event or circumstance may or may not occur, and that the description includes instances where the event occurs and instances where it does not.

Approximating language, as used herein throughout the specification and claims, may be applied to modify any quantitative representation that could permissibly vary without resulting in a change in the basic function to which it is related. Accordingly, a value modified by a term or terms, such as “about” , “approximately” , and “substantially” , are not to be limited to the precise value specified. In at least some instances, the approximating language may correspond to the precision of an instrument for measuring the value. Here and throughout the specification and claims, range limitations may be combined and/or interchanged, such ranges are identified and include all the sub-ranges contained therein unless context or language indicates otherwise.

Specifically, as used herein, the terms “substantially transverse” or “substantially parallel” should be interpreted to include angles within 15 degrees of 90 degrees and 0 degrees respectively.

A compact switchgear unit for use in an electrical power distribution system includes a breaker compartment containing a circuit breaker. The switchgear unit also includes a cable compartment disposed in proximity to the breaker compartment. The switchgear unit further includes a rack assembly coupled to the circuit breaker and a switch device operable to selectively electrically isolate the circuit breaker. Finally, the switchgear unit includes a motor assembly, arranged to control the switch device and the rack assembly. As a result, the switchgear unit described herein allows for a smaller overall switchgear unit and for more stable connections between circuit breakers and switchgear units.

FIG. 1 is a side view of an exemplary electrical power distribution system 100. A coordinate system 12 includes an X-axis, a Y-axis, and a Z-axis. Exemplary electrical power distribution system 100 includes at least one source providing power to at least one load via circuit protection devices 106. Electrical power sources may include, for example, one or more generators, electrical grids, or other devices that provide electrical current (and resulting electrical power) to loads. The electrical current is transmitted to loads through a bus bar assembly 108. Loads may include, but are not limited to only including, machinery, motors, lighting, and/or other electrical and mechanical equipment of a manufacturing or power generation or distribution facility.

In the exemplary embodiment, circuit protection devices 106 are housed in a switchgear unit 110. Specifically, in the exemplary embodiment, switchgear unit 110 includes a first circuit breaker 105 and a second circuit breaker 107. In the exemplary embodiment, first circuit breaker 105 and second circuit breaker 107 are vacuum circuit breakers. In alternative embodiments, first circuit breaker 105 and second circuit breaker 107 include any type of circuit breaker that enables electrical distribution system 100 to function as described herein. In the exemplary embodiment, first circuit breaker 105 and second circuit breaker 107 are positioned respectively within a first breaker compartment 118 and a second breaker compartment 120. First breaker compartment 118 and second breaker compartment 120 are arranged to allow

circuit breakers

105, 107 to each couple to two sets of electrical power lines. The two sets of electrical power lines include at least one load side power line 134 and at least one line side power line 136. Further, in the exemplary embodiment, load side power line 134 is coupled to bus bar assembly 108, and line side power line 136 is coupled to at least one electrical power source (not shown) including, without limitation, an AC power generator or a DC power supply. In the exemplary embodiment, line side power line 136 is coupled to a line bar 143 via a plug 150. Plug 150 may be, for example, an EN50181 plug. In alternative embodiments, plug 150 includes any plug that enables switchgear unit 110 to function as described herein. In the exemplary embodiment, switchgear unit 110 includes racks 102 to which circuit protection devices 106 are mounted within breaker compartments 118, 120. In the exemplary embodiment, switchgear unit 110 includes a front portion 112 and a rear portion 114 positioned opposite front portion 112. Additionally, front portion 112 and rear portion 114 are physically separated by a barrier wall 116.

In the exemplary embodiment, front portion 112 includes first breaker compartment 118, second breaker compartment 120, and a low voltage compartment 119. In alternative embodiments, front portion 112 includes only first breaker compartment 118. In alternative embodiments, front portion 112 includes any number of breaker compartments that enables switchgear unit 110 to function as described herein. In the exemplary embodiment, first breaker compartment 118 and second breaker compartment 120 are vertically aligned with respect to coordinate system 12, in a stacked configuration. In other words, first breaker compartment 118 is positioned on top of second breaker compartment 120. Further in the exemplary embodiment, each

breaker compartment

118, 120 includes a door 122 facilitating access to an interior of switchgear unit 110. Additionally in the exemplary embodiment, a base plate 123 defines a floor of each

breaker compartment

118, 120. Additionally, in the exemplary embodiments a motor compartment 125 is positioned beneath base plate 123 of first breaker compartment 118 and above second breaker compartment 120. Further, an additional motor compartment 125 is positioned below base plate 123 of second breaker compartment 120.

In the exemplary embodiment, each

circuit breaker

105, 107 includes a load connection member 130. Load connection member 130 connects

circuit breakers

105, 107 to bus bar assembly 108 when

circuit breakers

105, 107 are positioned at a connection point 138 on rack 102. For example, in the exemplary embodiment, first circuit breaker 105 is positioned at connection point 138. Additionally, in the exemplary embodiment, each

circuit breaker

105, 107 includes a line connection member 132. Line connection member 132 connects each

circuit breaker

105, 107 to bus bar assembly 108 when each

circuit breaker

105, 107 is positioned at connection point 138. In the exemplary embodiment, line connection member 132 and load connection member 130 are substantially in vertical alignment with one another. Further, in the exemplary embodiment, with respect to first circuit breaker 105, load connection member 130 is positioned below line connection member 132. Additionally, with respect to second circuit breaker 107, line connection member 132 is positioned below load connection member 130. In other words, in the exemplary embodiment, the vertical placement of load connection member 130 and line connection member 132 is reversed between first circuit breaker 105 and second circuit breaker 107.

In the exemplary embodiment, rear portion 114 of switchgear unit 110 includes a cable compartment 126. Further, bus bar assembly 108 is positioned within cable compartment 126. Bus bar assembly 108 includes a plurality of bus bars 124, bus housing 127, and two connection sleeves 128 arranged to receive a load connection member 130 of

circuit breakers

105, 107. In alternative embodiments, bus bar assembly 108 includes only one connection sleeve 128. In further alternative embodiments, bus bar assembly 108 includes any number of connection sleeves 128 that enables switchgear unit 110 to function as described herein. In the exemplary embodiment, bus bar assembly 108 is positioned between first breaker compartment 118 and second breaker compartment 120. In other words, bus bar assembly 108 does not extend a vertical distance beyond first breaker compartment 118 and second breaker compartment 120. Bus bar assembly 108 is described in more detail with respect to FIG. 2.

In the exemplary embodiment, first circuit breaker 105 is positioned at connection point 138 on rack 102 such that the load connection member 130 is positioned within connection sleeve 128 and coupled to a load bar 142 of bus bar assembly 108. Further, line connection member 132 of first circuit breaker 105 is positioned within connection sleeve 128 and coupled to a line bar 143. Additionally, in the exemplary embodiment, second circuit breaker 107 is positioned at an entry point 140 on rack 102 such that load connection member 130 is not coupled to load bar 142. Specifically, load connection member 130 and line connection member 132 of second circuit breaker 107 extend horizontally from second circuit breaker 107 to a free end proximate connection sleeves 128. Thus, in the exemplary embodiment, first circuit breaker 105 is in electrical communication with bus bar assembly 108 and second circuit breaker 107 is not in electrical communication with bus bar assembly 108.

In the exemplary embodiment, switchgear unit 110 includes voltage sensors 152. Voltage sensors 152 are coupled to load bar 142 and line bar 143 such that voltage sensors 152 may detect a voltage drop across

respective circuit breakers

105, 107. Specifically, in the exemplary embodiment, voltage sensors 152 are positioned within an insulative epoxy bushing extending from load bar 142 to line bar 143. In alternative embodiments, voltage sensors 152 include a partial discharge sensor arranged to detect a partial discharge current through

circuit breakers

105, 107. In further alternative embodiments, voltage sensors 152 have any positioning within switchgear unit 110 that enables switchgear unit 110 to function substantially as described herein.

Switchgear unit 110 includes a pair of current sensors 154 encircling line bar 143. In the exemplary embodiment, current sensors 154 have a generally annular shape. In alternative embodiments, current sensors 154 may have any shape that enables switchgear unit 110 to function as described herein. In further alternative embodiments, a transformer (not shown) in positioned adjacent current sensors 154 and encircles line bar 143 in a similar configuration as current sensors 154. In even further alternative embodiments, the transformer encircles line bar 143 and current sensors 154 do not encircle line bar 143.

In the exemplary embodiment, electrical power distribution system 100 includes at least one switch device 144 housed within switchgear unit 110. In the exemplary embodiment, switch device 144 is an earthing switch configured to provide grounding and selectively electrically isolate

circuit breakers

105, 107. Switch device 144 is positionable between an open position, broadly a first position, and a closed position broadly a second position. In the first position, switch device 144 allows current to flow through

circuit breakers

105, 107. In the second position, switch device 144 isolates at least one

circuit breaker

105, 107 and inhibits current flowing to the

isolated circuit breaker

105, 107. Specifically, in the exemplary embodiment, switch device 144 contacts a static connector 254 (shown in FIG. 3A) coupled to line bar 143. Accordingly, switch device 144 is configured to reduce the risk of electrical shock when operators access portions of electrical power distribution system 100. For example, in some embodiments, switch device 144 is moveable between the first position and the second position when at least one of

circuit breaker

105, 107 is removed from electrical power distribution system 100. In the exemplary embodiment, switchgear unit 110 includes two switch devices 144 paired with each line bar 143. In the exemplary embodiment, switch device 144 of first circuit breaker 105 is in the open position and switch device 144 of second circuit breaker 107 is in the closed position. In alternative embodiments, switchgear unit 110 includes any number of switch devices 144 that enable switchgear unit 110 to function as described herein.

Further, in the exemplary embodiment,

circuit breakers

105, 107 each include a rack assembly 146. Rack assembly 146 includes a rack screw 148 (shown in FIG. 3A) positioned between an outer stopper 260 (shown in FIG. 4A) and a socket 160(shown in FIG. 4A) . Rotation of rack screw 148 in a first direction moves

circuit breaker

105, 107 away from entry point 140 towards connection point 138. Rotation of rack screw 148 in a second, opposite direction moves

circuit breaker

105, 107 away from connection point 138 towards entry point 140. In alternative embodiments,

circuit breakers

105, 107 are positioned within switchgear unit 110 in any manner that enables switchgear unit 110 to function as described herein. Rack assembly 146 is described in more detail with respect to FIGS. 3A-3C and 4A-4C.

In the exemplary embodiment, switchgear unit 110 includes one or more motor assemblies 162. Specifically, in the exemplary embodiment motor assemblies 162 are positioned within motor compartments 125. In alternative embodiments, motor assembly 162 may be positioned in any manner that enables switchgear unit 110 to operate as described herein. In further alternative embodiments, switchgear unit 110 includes only one motor assembly 162. In the exemplary embodiment, motor assembly 162 of second breaker compartment 120 is coupled to switch device 144 such that motor assembly 162 is able to provide mechanical energy to transition switch device 144 from the open position to the closed position. Additionally, in the exemplary embodiment, motor assembly 162 of first breaker compartment 118 is coupled to rack assembly 146 such that motor assembly 162 is able to provide mechanical energy to rack assembly 146 to move first circuit breaker 105 from entry point 140 to connection point 138. In some embodiments, motor assembly 162 is coupled to both switch device 144 and rack assembly 146 and operable to control both switch device 144 and rack assembly 146. Motor assembly 162 is described in greater detail with respect to FIGS. 3A-3C.

In the exemplary embodiment, switchgear unit 110 has a length 164 defined along the X-axis with respect to coordinate system 12 extending from a front end 166 of switchgear unit 110 to a rear end 167 of switchgear unit 110. In the exemplary embodiment, length 164 is approximately 1.5 meters. In alternative embodiments, switchgear unit 110 has any length that enables switchgear unit 110 to function as described herein. Additionally, in the exemplary embodiment, switchgear unit 110 has a height 168 defined along the Z-axis with respect to coordinate system 12 extending from a bottom surface 169 of switchgear unit 110 to a top surface 170 of switchgear unit 110. In the exemplary embodiment, height 168 is approximately 2.2 meters. In alternative embodiments, switchgear unit 110 includes any height that enables switchgear unit 110 to function as described herein. In the exemplary embodiment, switchgear unit 110 has a width (not shown) defined along the Y-axis with respect to coordinate system 12 extending from a left sidewall (not shown) of switchgear unit 110 to a right sidewall (not shown) of switchgear unit 110. In the exemplary embodiment, the width is approximately. 5 meters. In alternative embodiments, switchgear unit 110 has any width that enables switchgear unit 110 to function as described herein.

FIG. 2 is an enlarged view of bus bar assembly 108 and load connection members 130 of switchgear unit 110 shown in FIG. 1.

In the exemplary embodiment, bus bar assembly 108 includes bus housing 127. Bus housing 127 extends from barrier wall 116 to surround bus bars 124 of bus bar assembly 108 and to surround load connection member 130 of first circuit breaker 105 and load connection member 130 of second circuit breaker 107.

In exemplary embodiment, bus bar assembly 108 includes bus bars 124 positioned between a top bar end 174 and a bottom bar end 176. Top bar end 174 is adjacent load bar 142 of first circuit breaker 105. Bottom bar end 176 is adjacent load bar 142 of second circuit breaker 107. Additionally, top bar end 174 is positioned within an upper mounting bracket 178 and bottom bar end 176 is positioned within a lower mounting bracket 180. Specifically, in the exemplary embodiment, top bar end 174 is supported within connection sleeve 128. Further, connection sleeve 128 is coupled to and supported by upper mounting bracket 178. In other words, bus bars 124 are supported within bus bar assembly 108 at top bar end 174 and bottom bar end 176. In the exemplary embodiment, bus bars 124 are arranged in a stacked configuration. That is, bus bars 124 are aligned with one another in a vertical direction. Moreover, each bus bar 124 is spaced from each adjacent bus bar in the vertical direction. In the exemplary embodiment, bus bars are epoxy insulated to increase durability and reduce the potential for arcing. In alternative embodiments, bus bars 124 include any insulation that enables bus bars 124 to function as described herein.

In the exemplary embodiment, load connection members 130 each include a load connection arm 182 and a load connection coupler 184. Coupler 184 is arranged to couple to load bar 142 at a coupling point 186. Arm 182 is arranged to support coupler 184. In the exemplary embodiment, sealing insulators 188 surround arms 182 such that sealing insulators 188 prohibit airflow between

breaker compartments

118, 120 and coupling point 186 when arms 182 are positioned within connection sleeve 128. Specifically, in the exemplary embodiment, sealing insulators 188 are in contact with and surround arms 182. Additionally, sealing insulators 188 extend from arms 182 to contact an inner peripheral wall 190 of connection sleeve 128. In the exemplary embodiment, sealing insulators 188 are composed of a soft silicone rubber material. In alternative embodiments, sealing insulators 188 are composed of any insulative material that enables switchgear unit 110 to function as described herein.

In the exemplary embodiment, bus bar assembly 108 includes a heat sink 192 positioned adjacent bus bars 124. Additionally bus bar assembly 108 includes a heat absorber 194 positioned adjacent heat sink 192. Specifically, in the exemplary embodiment, at least one of the advantages of sealing insulators 188 surrounding arms 182 compared with standard air insulation connections is that connection sleeve 128 is more compact. However, in some embodiments, sealing off coupling point 186 results in higher temperatures in load side line 134. Thus, heat sink 192 is arranged to dissipate excessive heat from bus bars 124. Further, heat absorber 194 is arranged to absorb dissipated heat from heat sink 192 and conduct heat to the outside surface of switchgear unit 110. In the exemplary embodiment, heat absorber 194 includes a heat conductive plate having a black chrome coating. In the exemplary embodiment, heat absorber 194 has a material heat absorptivity between about. 93-. 97. Further, heat absorber 194 has a material heat emissivity between about. 07 to. 15. Thus, in the exemplary embodiment, heat absorber 194 has an absorption to emission ratio between about 6 to 13. In the exemplary embodiment, heat absorber 194 is capable of maintaining long term stability during high operating temperatures. In particular, heat absorber 194 is operable to maintain long term stability in a 300 degrees Celsius environment. In alternative embodiments, heat sink 192 and heat absorber 194 function in any manner that enables switchgear unit 110 to function as described herein.

In the exemplary embodiment, bus bar assembly 108 includes a temperature sensor 196 arranged to monitor the temperature at coupling point 186 between load connection arm 182 and load bar 142. In the exemplary embodiment temperature sensor 196 is an infrared ray sensor coupled to bus housing 127 and horizontally aligned with coupling point 186. Additionally, temperature sensors 196 are positioned far enough from coupling point 186 such that a field of view 198 of temperature sensor 196 encompasses substantially all of coupling point 186.

FIG. 3A is an enlarged view of switchgear unit 110 shown in FIG. 1, in which motor assembly 162 is coupled to both switch device 144 and rack assembly 146. FIG. 3B is a bottom view of motor assembly 162 shown in FIG. 3A. FIG. 3C is a front view of a portion of a rack transmission 206 of rack assembly 146 shown in FIG. 3A.In the exemplary embodiment, first circuit breaker 105 is positioned at entry point 140 on rack assembly 146.

In the exemplary embodiment, motor assembly 162 is positioned beneath base plate 123 of first breaker compartment 118 adjacent barrier wall 116. Specifically, in the exemplary embodiment, motor assembly 162 is positioned within an access compartment 200. In alternative embodiments, motor assembly 162 is positioned within a motor compartment similar to motor compartment 125 shown in FIG. 1. In alternative embodiments, motor compartment 125 is sized to contain motor assembly 162.

In the exemplary embodiment, motor assembly 162 includes a motor 202, a motor gear 203, and a motor shaft 204 (shown in FIG. 3B) . Motor 202 is coupled to motor shaft 204 and is arranged to impart a torque on motor shaft 204 to rotate motor shaft 204 during operation of motor assembly 162. Motor gear 203 is coupled to be rotatable with motor shaft 204. In the exemplary embodiment, motor 202 is an electrical motor powered by an external power source (not shown) . In alternative embodiments, motor 202 includes any motor that enables motor assembly 162 to function as described herein.

In the exemplary embodiment, motor assembly 162 further includes a switch transmission 208 and rack transmission 206. Motor 202 is operable to drive rack transmission 206 to move circuit breaker 105 using rack assembly 146. Additionally, motor 202 is further operable to drive switch transmission 208 to selectively electrically isolate the circuit breaker 105 using switch device 144. In alternative embodiments, switchgear unit 110 includes only one of switch transmission 208 and rack transmission 206. Additionally, in the exemplary embodiment, motor assembly 162 includes a control switch (not shown) positioned on an exterior of switchgear unit 110 and operable to selectively activate motor assembly 162. Specifically, when motor 202 engages with rack transmission 206, motor 202 may be controlled to impart a torque in one direction during a loading operation and to impart a torque in an opposite direction during an unloading operation. Further, when motor 202 engages switch transmission 208, motor 202 may be controlled to impart a torque in one direction during a closing operation (i.e., transferring switch device 144 from the open position to the closed position) and to impart a torque in an opposite direction during an opening operation (i.e., transferring switch device 144 from the closed position to the open position) . In alternative embodiments, motor assembly 162 includes any control mechanism that enables motor assembly 162 to function as described herein.

In the exemplary embodiment, motor gear 203 is arranged to rotate a rack power gear 210 of rack transmission 206 when a rack clutch 212 of rack transmission 206 is engaged. Specifically, rack clutch 212 is coupled to a rack shaft 218 and is operable to selectively engage rack power gear 210 with motor gear 203. Additionally, in the exemplary embodiment, motor gear 203 is arranged to rotate a switch power gear 214 of switch transmission 208 when a switch clutch 216 of switch transmission 208 is engaged. Specifically, switch clutch 216 is coupled to switch shaft 228 and is operable to selectively engage switch power gear 214 with motor gear 203.

In the exemplary embodiment, motor gear 203 is arranged with respect to rack power gear 210 and switch power gear 214 such that motor gear 203 is only operable to rotate rack power gear 210 to rack circuit breaker 105 from entry point 140 to connection point 138 after motor gear 203 has engaged switch power gear 214 to transfer switch device 144 from the closed position to the open position. Further, motor gear 203 is only operable to rotate switch power gear 214 from the open position to the closed position after motor gear 203 has engaged rack power gear 210 to rack circuit breaker 105 from connection point 138 to entry point 140. As a result, motor assembly 162 prevents an operator from racking in circuit breaker 105 with switch device 144 in the closed position. Further, motor assembly 162 prevents an operator from closing switch device 144 while circuit breaker 105 is still racked at connection point 138. In alternative embodiments, motor gear 203 is operable with respect to rack power gear 210 and switch power gear 214 in any manner that enables motor assembly 162 to function as described herein.

In the exemplary embodiment, rack transmission 206 includes rack clutch 212, rack power gear 210, rack shaft 218, and a transfer gear 220. Additionally, in the exemplary embodiment, rack power gear 210 is arranged to impart a torque on rack shaft 218. Rotation of rack shaft 218 imparts rotation on transfer gear 220. Referring to FIG. 3C, transfer gear 220 is connected to an upper gear 222 via a transfer mechanism 224. In the exemplary embodiment, transfer mechanism 224 is a chain or belt. In alternative embodiments, transfer mechanism 224 includes any transfer mechanism 224 that enables rack transmission 206 to operate as described herein. In the exemplary embodiment, upper gear 222 is coupled to socket 160. Socket 160 receives rack screw 148 of rack assembly 146. Particularly, in the exemplary embodiment, socket 160 includes a threaded interior (not shown) . Thus, when rack screw 148 is positioned with socket 160, rotation of upper gear 222 causes rotation of rack screw 148. Rotation of rack screw 148 causes circuit breaker 105 to move along rack 226. Movement of circuit breaker 105 along rack 226 will be described in more detail with respect to FIGS. 4A-4C.

In the exemplary embodiment, switch transmission 208 includes switch clutch 216, switch power gear 214, and switch shaft 228. Additionally, in the exemplary embodiment, switch power gear 214 is arranged to impart a torque on switch shaft 228. In the exemplary embodiment, switch shaft 228 is threaded to receive a nut 230 thereon. In the exemplary embodiment, nut 230 is positioned within a guide block 232 (shown in FIG. 3B) that inhibits rotation of nut 230 when switch shaft 228 is rotating. Additionally, nut 230 is threaded such that rotation of switch shaft 228 in a first direction causes nut 230 to move laterally along switch shaft 228 towards barrier wall 116. Additionally, rotation of switch shaft 228 in a second direction causes nut 230 to move laterally along switch shaft 228 in an opposite direction away from barrier wall 116.

In the exemplary embodiment, nut 230 is coupled to a plurality of linkage members 234. Specifically, in the exemplary embodiment, nut 230 is coupled to two linkage members 234. In alternative embodiments, nut 230 is coupled to a single linkage member 234. In further alternative embodiments, nut 230 is coupled to any number of linkage members 234 that enables switch device 144 to operate as described herein. Linkage members 234 each include a first end 236 coupled to nut 230 and a second end 238 opposite first end 236. In the exemplary embodiment, second end 238 of each linkage member 234 is coupled to a lever 240 positioned on a base frame 242 of switch device 144. In the exemplary embodiment, lever 240 includes a first end 244 pivotably coupled to second end 238 of linkage member 234. Lever 240 also includes a second end 246 surrounding main shaft 248 of switch device 144. Additionally, lever 240 is coupled to main shaft 248 such that rotation of first end 244 of lever 240 by linkage member 234 causes rotation of main shaft 248. In the exemplary embodiment, rotation of main shaft 248 in a clockwise direction (relative to the view shown in FIG. 3A) effects rotation of a dynamic connector 250 from the open position to the closed position. Additionally, rotation of main shaft 248 in a counterclockwise direction (relative to the view shown in FIG. 3A) effects rotation of dynamic connector 250 from the closed position to the open position. In the exemplary embodiment, when switch device 144 is in the open position, dynamic connector 250 generally extends along the Z-axis with respect to coordinate system 12. When dynamic connector 250 is in the closed position, dynamic connector 250 generally extends along the X-axis such that dynamic connector 250 contacts static connector 254.

FIG. 4A is a side view of rack assembly 146 shown in FIGS. 3A-3C when rack screw 148 is not positioned within socket 160. FIG. 4B is a side view of the rack assembly 146 shown in FIG. 4A including first circuit breaker 105 positioned at entry point 140 and with rack screw 148 positioned within socket 160. FIG. 4C is a side view of the rack assembly 146 with first circuit breaker 105 positioned at connection point 138.

Referring to FIG. 4A, first circuit breaker 105 includes a plurality of wheels 256 positioned at a bottom 205 of first circuit breaker 105. In the exemplary embodiment, wheels 256 support first circuit breaker 105 within guide channels (not shown) extending along breaker compartment 118. Additionally, rack screw 148 extends from a socket end 258 to a stopper end 260. In the exemplary embodiment, during installation, first circuit breaker 105 is loaded onto base plate 123 using a mechanical lift. Once first circuit breaker 105 is loaded onto base plate 123, first circuit breaker 105 is positioned such that rack screw 148 engages socket 160.

Referring to FIG. 4B, rack screw 148 is rotatable by socket 160 when rack transmission 206 is controlled to move first circuit breaker 105 to connection point 138. Specifically, first circuit breaker 105 defines a threaded aperture (not shown) extending from a front end 262 to a back end 264 of first circuit breaker 105. The aperture receives rack screw 148 therethrough. Thus, rotation of rack screw 148 within aperture moves first circuit breaker 105 along rack screw 148. Additionally, in the exemplary embodiment, motor 202 (not shown in FIGS. 4A-4C) is operable to automatically disengage rack transmission 206 once first circuit breaker 105 is moved to connection point 138.

Referring to FIG. 4C, when first circuit breaker 105 is positioned at connection point 138, back end 264 abuts socket 160. In alternative embodiments, socket 160 is positioned further from connection point 138 such that socket 160 does not abut back end 264 when first circuit breaker 105 is positioned at connection point 138. Additionally, in the exemplary embodiment, first circuit breaker 105 is movable from connection point 138 to entry point 140 through substantially the same process described above, except that motor 202 (not shown in FIGS. 4A-4C) is controlled to rotate in an opposite direction.

FIG. 5A is a side view of a portion of switch device 144 in the open position. FIG. 5B is a side view of a portion of switch device 144 in the closed position.

Referring to FIG. 5A, switch transmission 208 includes guide block 232 positioned around switch shaft 228 and arranged to guide nut 230 as it moves along switch shaft 228. Particularly, as nut 230 moves rearward along switch shaft 228, lever 240 is rotated in a clockwise direction with respect to base frame 242. Particularly, in the exemplary embodiment, lever 240 is rotated approximately 45 degrees when switch device 144 transitions from the open position to the closed position.

Referring to FIG. 5B, switch device 144 includes a biasing member 266 that biases switch device 144 in the open position when switch device 144 is in the open position. In the exemplary embodiment, biasing member 266 includes a compression spring. In alternative embodiments, biasing member 266 includes any biasing device that enables switch device 144 to operate as described herein. In the exemplary embodiment, rotation of lever 240 effects a rotation of main shaft 248. Main shaft 248 is coupled to biasing member 266 such that biasing member 266 compresses initially during rotation until reaching a point where biasing member 266 is fully compressed. In the exemplary embodiment, rotation of lever 240 past that point causes biasing member 266 to bias dynamic connector 250 towards the closed position and towards contacting static connector 254.

FIG. 6 is a side view of an electrical power distribution system 100 including a modular switchgear unit 1110. Modular switchgear unit 1110 includes a first circuit breaker compartment 1118 and a second circuit breaker compartment 1120.

In the exemplary embodiment, modular switchgear unit 1110 is arranged such that each

breaker compartment

1118, 1120 includes a corresponding

bus bar assembly

1108, 1109. Thus,

bus bar assemblies

1108, 1109 are modular and removable to allow for varying configurations of switchgear unit 1110. For example, in some embodiments, switchgear unit 1110 includes three breaker compartments and three bus bar assemblies (not shown) . In further alternative embodiments, switchgear unit 1110 includes a control compartment (not shown) positioned between first breaker compartment 1118 and second breaker compartment 1120.

Further, in the exemplary embodiment a motor compartment 1125 is positioned below each

breaker compartment

1118, 1120. Motor compartments 1125 each include a motor assembly 1162 housed therein. Motor assemblies 1162 are arranged to control a rack assembly 1146 and a switch device 1144, similar to the embodiments described above. That is, motor assemblies 1162 are coupled to respective rack assembly 1146 and switch device 1144. In the exemplary embodiment, motor assemblies 1162 are further coupled to an underside of base plates 1123. In the exemplary embodiment, each switch device 1144 is coupled to a barrier wall 1116 proximate base plate 1123 of

breaker compartments

1118, 1120. Thus, an advantage of the modular configuration shown in FIG. 6 is that motor assemblies 1162 may control both switch devices 1144. Specifically, in the exemplary embodiment, line side power lines 1136 are coupled to first breaker compartment 1118 and second breaker compartment 1120 respectively below first bus bar assembly 1108 and second bus bar assembly 1109. Therefore, switch devices 1144 may each be positioned beneath line side power lines 1136 and be coupled to motor assemblies 1162 without being obstructed by first bus bar assembly 1108 or second bus bar assembly 1109.

An exemplary technical effect of the methods, systems, and apparatus described herein includes at least one of: (a) reducing the size of sealing insulated switchgear units; (b) improved cooling of bus bar assemblies due to positioning of heat sinks and heat absorbers; (c) more stable and less labor intensive process for connecting circuit breakers to bus bar assemblies; and (d) improved safety in ability to control earthing switches through motor assemblies.

Exemplary embodiments of electrical distribution apparatuses and methods of assembling electrical distribution apparatuses are described above in detail. The electrical distribution apparatuses and methods are not limited to the specific embodiments described herein but, rather, components of the electrical distribution apparatuses and/or operations of the methods may be utilized independently and separately from other components and/or operations described herein. Further, the described components and/or operations may also be defined in, or used in combination with, other systems, methods, and/or devices, and are not limited to practice with only the electrical distribution systems and apparatuses described herein.

The order of execution or performance of the operations in the embodiments of the disclosure illustrated and described herein is not essential, unless otherwise specified. That is, the operations may be performed in any order, unless otherwise specified, and embodiments of the disclosure may include additional or fewer operations than those disclosed herein. For example, it is contemplated that executing or performing a particular operation before, contemporaneously with, or after another operation is within the scope of aspects of the disclosure.

Although specific features of various embodiments of the disclosure may be shown in some drawings and not in others, this is for convenience only. In accordance with the principles of the disclosure, any feature of a drawing may be referenced and/or claimed in combination with any feature of any other drawing.

This written description uses examples to disclose the disclosure, including the best mode, and also to enable any person skilled in the art to practice the disclosure, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the disclosure 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 differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.

Claims

A switchgear unit for use in an electrical power distribution system, said switchgear unit comprising:

a breaker compartment containing a circuit breaker;

a rack assembly coupled to the circuit breaker, said rack assembly operable to move the circuit breaker between a first position and a second position within said breaker compartment;

a switch device operable to selectively electrically isolate the circuit breaker; and

a motor assembly comprising:

a motor;

a rack transmission coupled between said motor and said rack assembly; and

a switch transmission coupled between said motor and said switch device, said motor operable to drive said rack transmission to move the circuit breaker using said rack assembly, said motor further operable to drive said switch transmission to selectively electrically isolate the circuit breaker using said switch device.
The switchgear unit of Claim 1, wherein said rack transmission is coupled to a first side of said motor and said switch transmission is coupled to a second, opposite side of said motor.
The switchgear unit of Claim 1, wherein said motor assembly further comprises a motor shaft and a motor gear coupled to said motor shaft, said motor gear operable to rotate said motor shaft and said motor gear.
The switchgear unit of Claim 3, wherein said switch transmission comprises a switch shaft, a switch power gear coupled to said switch shaft, and a switch clutch coupled to said switch shaft, said switch clutch operable to selectively engage said switch power gear with said motor gear.
The switchgear unit of Claim 4, wherein said switch transmission further comprises a nut threadably coupled to said switch shaft, and a guide block positioned around said nut such that rotation of said switch shaft in a first direction causes a lateral movement of said nut along said switch shaft.
The switchgear unit of Claim 3, wherein said rack transmission comprises a rack shaft, a rack power gear coupled to said rack shaft, and a rack clutch coupled to said rack shaft, said rack clutch operable to selectively engage said rack power gear with said motor gear.
The switchgear unit of Claim 6, wherein said rack transmission further comprises a socket coupled to said rack power gear, said socket arranged to receive a rack screw of the circuit breaker therein.
The switchgear unit of Claim 1 further comprising:

a cable compartment containing a bus bar assembly, said bus bar assembly comprising a plurality of bus bars and a load bar coupled to said plurality of bus bars; and

a connection sleeve extending between said breaker compartment and said cable compartment, wherein said load bar extends into said connection sleeve.
The switchgear unit of Claim 8, wherein said load bar comprises at least one sensor operable to measure an electrical parameter of the switchgear unit.
The switchgear unit of Claim 8 further comprising a load connection member extending from the circuit breaker, said load connection member comprising an arm extending into said connection sleeve, a coupler coupleable to said load bar, and a sealing insulator surrounding said arm to contact a peripheral wall of said connection sleeve, the sealing insulator prohibiting airflow between said breaker compartment and said coupler.
The switchgear unit of Claim 10, wherein said sealing insulator comprises a silicone rubber material.
The switchgear unit of Claim 1, wherein said breaker compartment comprises a base plate, and wherein said motor assembly is coupled to said base plate.
A motor assembly for controlling a rack assembly and a switch device of a switchgear unit, said motor assembly comprising:

a motor;

a rack transmission coupled between said motor and the rack assembly; and

a switch transmission coupled between said motor and the switch device, said motor operable to drive said rack transmission to move a circuit breaker using the rack assembly, said motor further operable to drive said switch transmission to selectively electrically isolate the circuit breaker using the switch device.
The motor assembly of Claim 13, wherein said rack transmission is coupled to a first side of said motor and said switch transmission is coupled to a second, opposite side of said motor.
The motor assembly of Claim 13, further comprising a motor shaft and a motor gear coupled to said motor shaft, said motor gear operable to rotate said motor shaft and said motor gear.
The motor assembly of Claim 15, wherein said switch transmission comprises a switch shaft, a switch power gear coupled to said switch shaft, and a switch clutch coupled to said switch shaft, said switch clutch operable to selectively engage said switch power gear with said motor gear.
The motor assembly of Claim 16, wherein said switch transmission further comprises a nut threadably coupled to said switch shaft, and a guide block positioned around said nut such that rotation of said switch shaft in a first direction causes a lateral movement of said nut along said switch shaft.
The motor assembly of Claim 15, wherein said rack transmission comprises a rack shaft, a rack power gear coupled to said rack shaft, and a rack clutch coupled to said rack shaft, said rack clutch operable to selectively engage said rack power gear with said motor gear.
The motor assembly of Claim 18, wherein said rack transmission further comprises a socket coupled to said rack power gear, said socket arranged to receive a rack screw of the circuit breaker therein.
A method of using an electrical distribution system comprising:

positioning a circuit breaker within a breaker compartment of a switchgear unit;

coupling a rack assembly to the circuit breaker, the rack assembly operable to move the circuit breaker between a first position and a second position within the breaker compartment;

coupling a switch device within the switchgear unit, the switch device operable to selectively electrically isolate the circuit breaker; and

coupling a motor assembly to the rack assembly and the switch device, the motor assembly including a motor, a rack transmission coupled between the motor and the rack assembly, and a switch transmission coupled between the motor and the switch device, the motor operable to drive the rack transmission to move the circuit breaker using the rack assembly, the motor further operable to drive the switch transmission to selectively electrically isolate the circuit breaker using the switch device.