Patent Description:
The present disclosure relates generally to voltage harvesting devices used in power distribution systems and to power system architectures utilizing the voltage harvesting devices. The voltage harvesting devices transform distribution system voltages to power distribution system communication and control type devices that utilize or consume low power.

Document <CIT> discloses a voltage harvester device for power distribution system devices.

A frequent problem in almost any electrical power distribution system is a momentary disruption of electrical service that may be caused by environmental conditions. For example, <NUM>) lightening may strike in the vicinity of power lines, or <NUM>) wind may cause power lines strung between poles to momentarily touch each other or to touch a grounded conductor shorting the lines, or <NUM>) objects may fall across exposed wires and short the lines. Such events may cause a momentary power line short circuit or current surge. Most of these faults are self-correcting and do not significantly disrupt power distribution. However, some events are more serious and can trigger fault-interrupting devices to trip, causing a more serious power disruption.

For example, reclosers are inserted into power lines to protect a power distribution system. A recloser is a fault-interrupting device used to sense current, voltage, and/or frequency and isolate faulted portions of power distribution conductors. A recloser control device operates a recloser, which can be an electronic controller that operates with a low wattage input. Typically, such electronic controllers are located within a control box and derive their operating power from a large step-down transformer on the source side of the power distribution lines the recloser is protecting. This requires separate installation and maintenance. Electronic controllers located within the recloser as well as those within a control box also utilize a power storage component to operate the recloser when the recloser trips. Such stored power sources are batteries and capacitors that discharge when the recloser trips. In addition, the electronic controllers often include communication devices that are also powered by the step-down transformers and back-up battery supplies. Likewise, live tank devices utilize current transformers to harvest power from line current in order to operate and communicate when lines are loaded. Utilizing a separate step-down transformer and stored power source significantly increase the cost and maintenance requirements to protect the power distribution lines. In the case of a live tank device, requiring lines to be constantly loaded is not realistic. Thus, a need exists for a compact, lower cost alternative to the separate step-down transformer, power storage component, and line load requirements to provide operating power to reclosers, controllers, communication devices, and other devices used in power distribution systems that rely on low voltage, low power inputs.

The invention provides a voltage harvesting device for use in power distribution systems according to claim <NUM>. The invention also provides a voltage harvesting circuit for use in power distribution systems according to claim <NUM>. The present disclosure provides exemplary embodiments of voltage harvesting devices used in power distribution systems. The present disclosure also provides exemplary embodiments of power distribution system architectures utilizing the voltage harvesting devices. The present disclosure also provides exemplary embodiments of transformation circuits that can be incorporated into the voltage harvesting devices of the present disclosure, such as an insulator utilized in conventional power distribution system components. Generally, the voltage harvesting devices and the transformation circuits according to the present disclosure transform loaded or unloaded live line voltages to produce output power that can be used to supply operating power for power distribution system communication and control type devices that utilize or consume low power.

In an exemplary embodiment, the voltage harvesting device includes a housing and a transformation circuit embedded in or encased within the housing. The transformation circuit includes a first impedance component and a second impedance component arranged as a voltage divider such that the transformation circuit has an output AC voltage that is a factor of about <NUM> percent to about <NUM> percent of a source line voltage. In this exemplary embodiment, the first impedance component is a transformer, and the second impedance component is a resistor.

In another exemplary embodiment, the transformation circuit includes a resistor and a transformer. The transformer has a first terminal for connecting to a line voltage source and a second terminal connected to a first terminal of the resistor. The resistor has a second terminal for connecting to actual ground. A secondary winding of the transformer sits at line potential so that it has a floating ground reference and outputs an AC voltage in the range of about <NUM>-<NUM> VAC relative to the line voltage source.

A more complete appreciation of the present disclosure and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:.

The present disclosure provides exemplary embodiments of voltage harvesting devices used in power distribution systems and power distribution system architectures utilizing the voltage harvesting devices. Generally, the voltage harvesting device according to the present disclosure transforms distribution line voltages to produce low output power for power distribution system devices. More specifically, the voltage harvesting device utilizes available high voltage AC on power distribution conductors to provide low voltage electrical power for communication and control type devices without the use or cost of a dedicated step-down transformer or other power source, such as a battery or a capacitor. The voltage harvesting device can be distributed individually, as part of a power distribution system type component kit, or the voltage harvesting device can be integrated with or into various power distribution system type devices. For example, the voltage harvesting device may be incorporated into an insulator and installed with a recloser.

The power distribution system communication and control type devices contemplated by the present disclosure include, but are not limited to, recloser control systems, communication systems for smart-grid applications, pole-mounted remote terminal units (RTUs) that communicate via cellular, WiFi, Ethernet, mesh networks, and other communication methods to a central system, such as SCADA or the IEC <NUM> standard defining communication protocols. For ease of description, the power distribution system communication and control type devices may also be referred to herein collectively as the "control devices" in the plural and as the "control device" in the singular.

In addition, the power distribution system type components and associated control devices contemplated by the present disclosure include, but are not limited to, line disconnects, fault interrupters, power line monitors, power factor correction devices, and load switching devices and other overhead distribution switches, insulators, and arresters. Non-limiting examples of line disconnects includes sectionalizers. Non-limiting examples of fault interrupters include breakers and reclosers. Non-limiting examples of power line monitors includes sensors and fault locators. Non-limiting examples of power factor correction devices include capacitor switches. Non-limiting examples of load switching devices include load-break switches. For ease of description, the power distribution system type components may also be referred to herein collectively as the "distribution components" in the plural and the "distribution component" in the singular.

Referring to <FIG> and <FIG>, exemplary embodiments of a voltage harvesting device according to the present disclosure are shown. The voltage harvesting device <NUM> includes voltage harvesting circuitry enclosed in or encased in a housing <NUM>. In one embodiment, the voltage harvesting circuitry includes transformation circuitry <NUM>. In other embodiments, the voltage harvesting circuitry includes the transformation circuitry <NUM> and other circuit components as described in more detail below.

Referring to <FIG>, the transformation circuitry <NUM> is used to transform high voltage AC on high voltage transmission or distribution conductors to an output power level that can be used to supply operating power for control devices whether or not there is line current (load) on the high voltage distribution conductor. In one exemplary embodiment, seen in <FIG>, the transformation circuitry <NUM> includes a resistor <NUM> and a transformer <NUM>. The transformer <NUM> is connected between the line voltage (Vsource) and one side of the resistor <NUM>, as shown. The other side of the resistor <NUM> is connected to pole ground. It is noted that pole ground is earth ground, actual ground or the like. In the exemplary embodiment of <FIG>, the resistor <NUM> drops the line voltage (Vsource) by a large factor dependent on the source line voltage. For example, a 15kV single phase line voltage, or <NUM>. 66kV, may be dropped by a factor ranging between about <NUM> kV to about <NUM>. 5kV across the resistor <NUM>. The voltage drop factor may range from about <NUM>-<NUM>% of the single phase source voltage. Further, since the resistor <NUM> is connected in series with the primary winding 24a of the transformer <NUM>, the resistor <NUM> is subjected to and configured to handling a high continuous wattage. The wattage is dependent upon a number of factors including the resistor size and construction, e.g., parallel configuration. As an example, the high continuous wattage may be in the range of between about 20W to about 100W. However, this wattage may change dependent on the line voltage and the output requirements of the circuit. As a non-limiting example, for a single-phase line voltage of <NUM> kV the high continuous wattage may be about 60W.

Referring to <FIG>, the transformation circuitry <NUM> is used to transform high voltage AC on high voltage transmission or distribution conductors to an output power level that can be used to supply operating power for control devices whether or not there is line current (load) on the high voltage distribution conductor. In one exemplary embodiment, seen in <FIG>, the transformation circuitry <NUM> includes a resistor <NUM> and a transformer <NUM>. The resistor <NUM> is connected between the line voltage (Vsource) and one side of the primary winding 24a of the transformer <NUM>, as shown. The other side of the primary winding 24a of the transformer <NUM> is connected to pole ground. It is noted that pole ground is earth ground, actual ground or the like. In the exemplary embodiment of <FIG>, the resistor <NUM> drops the line voltage (Vsource) by a large factor dependent on the source line voltage. For example, a 15kV single phase line voltage, or <NUM>. 66kV, may be dropped by a factor ranging between about 4kV to about <NUM>. 5kV across the resistor <NUM>. The voltage drop factor may range from about <NUM>-<NUM>% of the single phase source voltage. Further, since the resistor <NUM> is connected to the line voltage (Vsource), the resistor <NUM> is subjected to and configured to handling a high continuous wattage. The wattage is dependent upon a number of factors including the resistor size and construction, e.g., parallel configuration. As an example, the high continuous wattage may be in the range of between about 20W to about 100W. However, this wattage may change dependent on the line voltage and the output requirements of the circuit. As a non-limiting example, for a single-phase line voltage of <NUM> kV the high continuous wattage may be about 60W.

As mentioned previously, the transformer <NUM> is provided to drop the high voltage across the resistor <NUM> by a factor ranging between about <NUM> kV to about <NUM> kV and, additionally to drop the voltage across the transformer by a factor ranging between about <NUM> kV to about <NUM> kV such that the output AC voltage of the entire transformation circuit <NUM> is a factor of between about <NUM> percent and about <NUM> percent of the line voltage source. In the exemplary embodiment described herein the output AC voltage of the transformation circuit <NUM> is about <NUM>-250V relative to the source line voltage (Vsource). It should be understood that for higher source line voltages, additional resistors <NUM> or transformers <NUM> may be added in series or parallel in order to accommodate the larger voltage drops and to handle the higher wattages. For example, if the line voltage (Vsource) fed to the resistor <NUM> is about <NUM> kV, the voltage drop across the resistor <NUM> will be about <NUM> kV, and the voltage drop across the transformer primary is <NUM> kV, then the transformer <NUM> may output <NUM> VAC at about <NUM> watts of power. However, the properties of the transformer <NUM> may vary depending upon a number of factors including the source line voltage (Vsource), the high continuous wattage, line impedances, winding impedances, core impedances, the desired output voltage, the desired output wattage, and other properties associated with the transformer <NUM>. Non-limiting examples of the transformer properties include: size of the core of the transformer, the material used to form the core, the gauge of the wire windings around the core, the insulation surrounding the wire windings, and the number of windings for the primary and secondary (i.e., turns ratio). As a non-limiting example, a suitable size of the core may be in the range of a few inches to about <NUM> inches in length and height and few inches to about <NUM> inches in width and can be in any shape capable of fitting within the housing dimensions. Non-limiting examples of suitable materials for forming the core include conductive, magnetic, highly permeable, metallic material with low coercivity and hysteresis, such as iron (ferrite), steel, silicon, or any combination thereof. As a non-limiting example, the wire gauge of the wire windings around the core of the transformer may range from about <NUM> gauge to about <NUM> gauge. As a non-limiting example, the thickness of the wire insulation surrounding wire forming the core may range from about <NUM> to about <NUM> thick. As a non-limiting example, the primary to secondary ratio of the core may range from about <NUM>:<NUM> (<NUM> to <NUM>), seen in <FIG> to about <NUM>:<NUM> (<NUM> to <NUM>), seen in <FIG>, though it should be understood by a person skilled in the art that this ratio can change dependent on the secondary load requirement, the form factor of the housing, and the source voltage. These and other properties should be sufficient to transform the high line voltage (Vsource) to a lower output AC voltage.

Continuing to refer to <FIG> and <FIG>, the secondary winding 24b of the transformer <NUM> in the transformation circuit <NUM> sits at line potential so that it has a floating ground reference. As a result, while it may appear that the transformation circuit <NUM> steps down the line voltage (Vsource), the transformation circuit <NUM> steps up the line voltage by a voltage factor, which is relatively small compared to the line voltage (Vsource). For example, in the exemplary embodiment shown in <FIG>, the voltage factor is about <NUM> VAC such that the output voltage (Vf) of the transformation circuit <NUM> is about <NUM> VAC (i.e., <NUM>. 66kV single phase line voltage plus 48VAC output) with reference to actual ground.

The resistor <NUM> and the transformer <NUM> of the transformation circuit <NUM> shown in <FIG> and <FIG> create an impedance-matched voltage divider. As noted above, the properties of the resistor <NUM> and the transformer <NUM> can vary and can be selected based upon the input line voltage (Vsource), the high continuous input power, the desired output voltage (Vf) and the desired output wattage of the voltage harvesting device <NUM>. As a non-limiting example, for a transformation circuit <NUM> rated for an <NUM> kV single-phase voltage (<NUM> kV three-phase voltage), the resistor <NUM> may be sized from about <NUM> kΩ to about <NUM> MΩ in order to provide a voltage drop of about <NUM> VAC, at about 60W to about 100W continuous watts. In addition, the properties for the transformer <NUM> may be designed with a <NUM>:<NUM> ratio (<FIG>) and a <NUM>:<NUM> (<FIG>), using a silicon steel or equivalent core with <NUM>-gauge wire having an insulation thickness of about <NUM>, in order to provide a 1200V drop across the primary windings of the transformer <NUM>. It is noted that a higher turns ratio may be utilized to reduce the continuous wattage across the resistor <NUM>.

Referring again to <FIG>, an exemplary embodiment of the housing <NUM> of the voltage harvesting device <NUM> is shown. The housing <NUM> may come in various shapes and sizes depending upon a number of factors, including the components, e.g., the resistor <NUM> and the transformer <NUM>, used in the transformation circuit <NUM>, the source line voltage (Vsource), the desired output voltage of the voltage harvesting circuitry, and the desired output power of the voltage harvesting circuitry. Generally, as a non-limiting example, the dimensions of the housing <NUM> may range from about <NUM>" x <NUM>" x <NUM>" to about <NUM>" x <NUM>" x <NUM>" or larger, dependent on the core dimensions of the transformer <NUM>. As a specific example, for an <NUM> kV single-phase line voltage, the resistor <NUM> may be about <NUM> inches in length, about <NUM> inches in width and about <NUM> inches in height, and the transformer <NUM> may be about <NUM> inches in length, about <NUM>-<NUM> inches in width and about <NUM> inches in height, which would result in a housing <NUM> of about <NUM> inches in length, about <NUM> inches in width and about <NUM> inches in height.

Continuing to refer to <FIG>, the housing <NUM> may have a flat upper surface 50a that permits a distribution component <NUM>, e.g., a recloser, to be connected to the housing <NUM>, as seen in <FIG> and <FIG>. The housing <NUM> may have a flat lower surface 50b that permits the voltage harvesting device <NUM> to be connected to a mounting structure <NUM>, as seen in <FIG> and <FIG>. A terminal connector <NUM> may extending from the housing <NUM> and can be used to connect the input side of the voltage harvesting device <NUM> to the line voltage (Vsource). A terminal <NUM>, e.g., a pin terminal, may also extend from the housing <NUM> and can be used to connect the output side of the voltage harvesting device <NUM> to a subsequent component, such as an overvoltage circuit <NUM>, a voltage converter <NUM> or a control device <NUM>, e.g., a low wattage control device, described below and seen in <FIG>.

The transformation circuit <NUM> of the voltage harvesting circuitry may be potted or otherwise formed in an insulating material forming the housing <NUM>. Non-limiting examples of insulating materials include, cycloaliphatic epoxy, resin, polymer, porcelain and/or other insulating material known in the art that is durable, weather resistant and that allows for sufficient dissipation of heat generated by the transformation circuitry <NUM>, such as through sheds <NUM> of various diameters, seen in <FIG>.

Referring again to refer to <FIG> and <FIG>, the transformation circuitry <NUM> described above forms the voltage harvesting circuitry within the voltage harvesting device <NUM>. To protect the voltage harvesting device <NUM> from excessive voltages and transients, a first overvoltage disconnect device <NUM> may be connected to the input side of the transformation circuitry <NUM>. In other words, the first overvoltage disconnect device <NUM> may be connected between the line voltage (Vsource) and the transformation circuitry <NUM>. The first overvoltage disconnect device <NUM> would be provided to protect the transformation circuit <NUM> from overvoltage conditions, such as those caused by transients, faults or other disturbances on the line as is known in the art. Non-limiting examples of the first overvoltage disconnect device <NUM> include, daisy-chained TVS diodes, FETs, PTC fuses, and/or similar components and associated circuitry capable of providing overvoltage protection. In the exemplary embodiment of <FIG>, the first overvoltage disconnect device <NUM> is a series of daisy-chained TVS diodes or similar circuit connected in parallel with the transformation circuit <NUM>.

An optional second overvoltage disconnect device <NUM> may be connected to the output side of the transformation circuitry <NUM>, i.e., between the output of the transformation circuit <NUM> and subsequent circuitry coupled to the voltage harvesting device <NUM>. The second overvoltage disconnect device <NUM> may be provided to protect the output side of the transformation circuit <NUM> from overvoltage conditions, so that large line voltage or current disturbances are not experienced across the secondary of the transformation circuit <NUM> as is known. Non-limiting examples of the second overvoltage disconnect device include, daisy-chained bidirectional TVS diodes, FETs, fuse, PTC fuses, diodes, and/or similar components and associated circuitry capable of providing overvoltage and overcurrent protection. In the exemplary embodiment of <FIG>, the second overvoltage disconnect device <NUM> is a series of daisy-chained bidirectional TVS diodes connected in parallel with the output of the transformation circuit <NUM> as shown. In one embodiment, the second overvoltage disconnect <NUM> may be included within the control device <NUM> instead of the voltage harvesting device circuitry.

To convert the output AC voltage (Vf) of the transformation circuit <NUM> to a DC voltage for the control device <NUM>, a voltage converter <NUM> may be connected to the voltage harvesting device <NUM> or the optional second overvoltage disconnect device <NUM>. The voltage converter <NUM> may be a conventional AC/DC converter or other device or circuitry capable for converting AC voltage to DC voltage. In the exemplary embodiment of <FIG>, the voltage converted <NUM> converts the <NUM> VAC output (Vf) from the transformation circuit <NUM> to provide a <NUM> VDC operating voltage for the control device <NUM>. In the exemplary embodiments of <FIG> and <FIG>, the voltage converter <NUM> converts the <NUM> VAC output voltage (Vf) from the transformation circuit <NUM> to provides a <NUM> VDC operating voltage at <NUM> watts for the control device <NUM>.

The circuit of <FIG>, with a line voltage (Vsource) of <NUM> kV AC operates in the following manner. The line voltage (Vsource) is fed into the transformation circuit <NUM> having a 1MΩ resistor <NUM> and the ground is earth ground, via e.g., a utility pole ground. The voltage drop across the resistor <NUM> reduces the <NUM> kV to <NUM> kV, which is a voltage drop of about 7400V. The <NUM> kV is fed to the transformer <NUM> (having approximately a <NUM>:<NUM> primary to secondary ratio), which drops the <NUM> kV to output a voltage (Vf) of about 48VAC at about 10W. That is, the secondary of the transformer <NUM> in the transformation circuit <NUM> outputs about 48VAC at 10W. The impedance of the resistor <NUM> and the transformer <NUM> should be matched so that the wattage created from the current flowing through the transformation circuit <NUM> does not drop. It is noted that in the configuration shown, the secondary of the transformer and the remaining portions of the circuit are held at line potential, acting as floating ground reference. As a result, the output of the transformation circuit <NUM> (Vf) is approximately 8708V. However, with the floating ground being at approximately <NUM> kV the effective output voltage of the transformation circuit <NUM> is about <NUM> VAC. Thus, the additional step 'up' from the line voltage potential is what achieves the voltage harvesting from the line potential whether or not there is a load present on the line. The output voltage (Vf) of the transformation circuit <NUM>, e.g., the 48VAC, is then input into the AC to DC converter <NUM> which can have characteristics that convert the 48VAC to the same or a lower DC voltage so that the converter outputs a DC voltage for a prescribed application as is known. For example, to power a control device <NUM> that is a communication radio for a recloser as the distribution component <NUM>, may require approximately 5VDC at <NUM>. In such an example, the voltage converter <NUM> would be configured to convert the 48VAC at about 10W to 5VDC at about <NUM>. The 5VDC at about <NUM>. 5W output of the voltage converter <NUM> is then fed into the communication radio <NUM>, also sitting at line potential, to continuously power the communication radio <NUM> whether or not a load current is present on the line.

As noted above, in the event line voltage exceeds a certain threshold, e.g., 95kV, the first overvoltage disconnect device <NUM> would short to effectively disconnect the transformation circuit <NUM> from the line overvoltage condition This overvoltage value may be higher or lower depending on, for example, the corresponding rated line voltage (Vsource) where it is being utilized, the amount of the voltage seen across the primary winding of the transformer (or resistor, depending on which circuit is being considered, e.g., <FIG>, <FIG>, <FIG> or <FIG>, <FIG>, <FIG>). As noted above, in the event the secondary voltage or current, i.e., on the output side of the transformation circuit <NUM>, exceeds a certain threshold, e.g., 50V to <NUM>. 6kV, the second overvoltage disconnect device <NUM> would short to effectively disconnect the transformation circuit <NUM> from the output side overvoltage condition. The secondary overvoltage disconnect includes a range of values that depend on, for example, the nominal line voltage of the line on which it is utilized and the output voltage being supplied to the converter. The second overvoltage disconnect serves to protect the additional components, i.e., the AC/DC converter <NUM> and control device <NUM> in the case where the transformer or resistor/capacitor/inductor fails or in the case of an overvoltage event on the line which effectively raises the 'ground' line potential of the circuit.

Turning now to <FIG>, <FIG>, <FIG>, <FIG>, <FIG> and <FIG>, additional exemplary embodiments of the circuitry that may be included in the voltage harvesting device <NUM> according to the present disclosure are shown. In the exemplary embodiment of <FIG>, <FIG> and <FIG>, the voltage harvesting circuitry includes the overvoltage disconnect <NUM>. The overvoltage disconnect <NUM> may or may not be included in the voltage harvesting circuitry, and the voltage converter <NUM> is external to the voltage harvesting device <NUM>. In the exemplary embodiment of <FIG>, <FIG> and <FIG>, the voltage harvesting circuitry includes the overvoltage disconnect <NUM> and the voltage converter <NUM>. The overvoltage disconnect <NUM> may or may not be included in the voltage harvesting device <NUM>.

Referring to <FIG> and <FIG>, exemplary embodiments of a single-phase power distribution system architecture incorporating the voltage harvesting device according to the present disclosure are shown. In the exemplary embodiment of <FIG>, the distribution component <NUM> is a recloser, the control device <NUM> is a recloser peripheral device, such as a communication module, and the voltage harvesting device <NUM> includes one of the embodiments shown in <FIG> and <FIG>. The voltage harvesting device <NUM> can be mounted to a utility pole and the recloser <NUM> can be mounted to one end of the voltage harvesting device <NUM>, as seen in <FIG> and <FIG>. The voltage harvesting device <NUM> is connected to the line phase conductor having a line voltage (Vsource), e.g., an <NUM> kV source line voltage. When triggered, the recloser <NUM> would open, disconnecting the load from the line voltage (Vsource). Whether the recloser <NUM> is closed or open, the line voltage (Vsource) is fed to the voltage harvesting device <NUM> from the source side, which transforms the line voltage (Vsource), e.g., the <NUM> kV to <NUM> VAC at <NUM> watts, and the voltage converter <NUM> converts the <NUM> VAC to 5VDC at <NUM> watts. The 5VDC at <NUM> watts is output by the voltage harvesting device <NUM> and fed to the recloser communication module <NUM> which can be used to communicate and power a control element for the operation of the recloser <NUM> via an interface, such as a serial port or hardwire connection, or wireless connection (see, <FIG>) between the recloser communication module <NUM> and the recloser <NUM>. In one embodiment, the communication module <NUM> can be utilized to provide power to charge capacitors or other energy storage elements in the recloser in order to perform functions, such as closing or opening the device after an open circuit or unloaded condition.

In the exemplary embodiment of <FIG>, the distribution component <NUM> is a recloser, the control device <NUM> is a recloser wireless communication and/or control device, such as an RTU, and the voltage harvesting device <NUM> includes one of the embodiments shown in <FIG> and <FIG>. The voltage harvesting device <NUM> can be mounted to a utility pole and the recloser <NUM> can be mounted to one end of the voltage harvesting device <NUM>, as seen in <FIG> and <FIG>. The voltage harvesting device <NUM> is connected to a single phase line conductor having a line voltage (Vsource), e.g., an <NUM> kV line voltage. When triggered, the recloser <NUM> would open, disconnecting the load from the line voltage (Vsource). Whether the recloser <NUM> is closed or open, the source line voltage (Vsource) is fed to the voltage harvesting device <NUM> which transforms the line voltage (Vsource), e.g., the <NUM> kV, to <NUM> VAC at <NUM> watts and the voltage converter <NUM> converts the <NUM> VAC to 5VDC at <NUM> watts. The 5VDC at <NUM> watts is output by the voltage harvesting device <NUM> and fed to the communication and/or control device <NUM> which may control the operation of the recloser <NUM> via wireless communication between the communication and/or control device <NUM> and the recloser <NUM> using known communication techniques and protocols.

In another exemplary embodiment described with reference to <FIG>, the control device <NUM> may be independent of the distribution component <NUM> or may be a distribution component itself, having additional circuitry within it to communicate and transmit or indicate data regarding line conditions.

Referring to <FIG> and <FIG>, an exemplary embodiment of a three-phase power distribution system architecture incorporating the voltage harvesting device according to the present disclosure is shown. In this exemplary embodiment, each phase (<NUM>, <NUM>, or <NUM>) of a three-phase line is fed into a separate voltage harvesting device <NUM>, the output of which is fed to a separate control device <NUM>, such as an RTU, which controls one or more separate distribution components <NUM> similar to that shown in <FIG> and <FIG> and described above. In the embodiment of <FIG> the control devices <NUM> are hardwired to the distribution component <NUM>. In the embodiment of <FIG> a control device <NUM> (e.g., an RTU) wirelessly communicates with multiple distribution components <NUM> and is powered via one or more of the voltage harvesting devices <NUM> on each of the multiple distribution components <NUM>.

The voltage harvesting device according to the present disclosure may be used with live ungrounded devices or with pole-based control devices, which are usually grounded. It will be understood that various modifications can be made to the embodiments of the present disclosure. All values set forth herein are exemplary and can be modified depending upon the line voltage (Vsource) and line continuous wattage, the voltage and power requirements of the control device, and the characteristics and properties of the voltage harvesting device. This includes the values for the physical dimensions and the resistance and power characteristics of the resistor and transformer and other elements used with or incorporated into the voltage harvesting device, such as the overvoltage disconnects and the voltage converter. Additionally, though the voltage harvesting circuitry within the voltage harvesting device may only include the transformation circuit, i.e., the resistor/transformer voltage divider, the voltage harvesting circuitry may also include other elements, such as the first overvoltage disconnect device, the second overvoltage disconnect device and/or the voltage converter. Therefore, the above description should not be construed as limiting the disclosure, but merely as embodiments thereof. Those skilled in the art will envision other modifications within the scope of the invention as defined by the claims appended hereto.

Referring now to <FIG> additional exemplary embodiments of the transformation circuitry <NUM> according to the present disclosure are shown. These exemplary embodiments of the transformation circuitry <NUM> may be substituted for the transformation circuitry <NUM> described herein above. In the exemplary embodiment of <FIG>, the transformation circuitry <NUM> includes an inductor <NUM> and the transformer <NUM>. The transformer <NUM> is connected between the line voltage (Vsource) and one side of the inductor <NUM>, as shown. The other side of the inductor <NUM> is connected to pole ground. It is noted that pole ground is earth ground, actual ground or the like. In the exemplary embodiment of <FIG>, the inductor <NUM> drops the line voltage (Vsource) by a large factor dependent on the source line voltage. For example, using a <NUM> kH inductor <NUM> and a transformer <NUM> with a <NUM>:<NUM> turns ratio, a 15kV single phase line voltage or <NUM>. 66kV, may be dropped by a factor ranging between about <NUM> kV to about <NUM>. 5kV across the inductor <NUM>. The voltage drop factor may range from about <NUM>-<NUM>% of the single phase source voltage. Further, since the inductor <NUM> is connected in series with the primary winding 24a of the transformer <NUM>, the inductor <NUM> is subjected to and configured to handling a high continuous wattage. The wattage is dependent upon a number of factors including the inductor size and construction, e.g., parallel configuration. As an example, the high continuous wattage may be in the range of between about 20W to about 100W. However, this wattage may change dependent on the line voltage and the output requirements of the circuit. As a non-limiting example, for a single-phase line voltage of <NUM> kV the high continuous wattage may be about 60W.

In the exemplary embodiment of <FIG>, the transformation circuitry <NUM> includes a capacitor <NUM> and the transformer <NUM>. The transformer <NUM> is connected between the line voltage (Vsource) and one side of the capacitor <NUM>, as shown. The other side of the capacitor <NUM> is connected to pole ground. It is noted that pole ground is earth ground, actual ground or the like. In the exemplary embodiment of <FIG>, the capacitor <NUM> drops the line voltage (Vsource) by a large factor dependent on the source line voltage. For example, using a <NUM> nF capacitor <NUM> and a transformer <NUM> with a <NUM>:<NUM> turns ratio, a 15kV single phase line voltage or <NUM>. 66kV, may be dropped by a factor ranging between about <NUM> kV to about <NUM>. 5kV across the capacitor <NUM>. The voltage drop factor may range from about <NUM>-<NUM>% of the single phase source voltage. Further, since the capacitor <NUM> is connected in series with the primary winding 24a of the transformer <NUM>, the capacitor <NUM> is subjected to and configured to handling a high continuous wattage. The wattage is dependent upon a number of factors including the inductor size and construction, e.g., parallel configuration. As an example, the high continuous wattage may be in the range of between about 20W to about 100W. However, this wattage may change dependent on the line voltage and the output requirements of the circuit. As a non-limiting example, for a single-phase line voltage of <NUM> kV the high continuous wattage may be about 60W.

In the exemplary embodiment of <FIG>, the transformation circuitry <NUM> includes a parallel resistor network <NUM> and the transformer <NUM>. The parallel resistor network <NUM> includes two resistors RA and RB. The transformer <NUM> is connected between the line voltage (Vsource) and one side of the parallel resistor network <NUM>, as shown. The other side of the parallel resistor network <NUM> is connected to pole ground. It is noted that pole ground is earth ground, actual ground or the like. In the exemplary embodiment of <FIG>, the parallel resistor network <NUM> drops the line voltage (Vsource) by a large factor dependent on the source line voltage. For example, using two <NUM> KΩ resistors RA and RB and a transformer <NUM> with a <NUM>:<NUM> turns ratio, a 15kV single phase line voltage or <NUM>. 66kV, may be dropped by a factor ranging between about <NUM> kV to about <NUM>. 5kV across the parallel resistor network <NUM>. The voltage drop factor may range from about <NUM>-<NUM>% of the single phase source voltage. Further, since the parallel resistor network <NUM> is connected in series with the primary winding 24a of the transformer <NUM>, the parallel resistor network <NUM> is subjected to and configured to handling a high continuous wattage. The wattage is dependent upon a number of factors including the inductor size and construction, e.g., parallel configuration. As an example, the high continuous wattage may be in the range of between about 20W to about 100W. However, this wattage may change dependent on the line voltage and the output requirements of the circuit. As a non-limiting example, for a single-phase line voltage of <NUM> kV the high continuous wattage may be about 60W.

In the exemplary embodiment of <FIG>, the transformation circuitry <NUM> includes a parallel resistor and a series resistor network <NUM> and the transformer <NUM>. The parallel resistor and a series resistor network <NUM> may also be referred to herein as the resistor network <NUM>. The resistor network <NUM> includes two resistors RA and RB in parallel and a resistor Rc in series with the two parallel resistors RA and RB. In other exemplary embodiments, the resistor network <NUM> may include two or more individual resistors, e.g., resistors RA and RC, in series. The transformer <NUM> is connected between the line voltage (Vsource) and one side of the resistor network <NUM>, as shown. The other side of the resistor network <NUM> is connected to pole ground. It is noted that pole ground is earth ground, actual ground or the like. In the exemplary embodiment of <FIG>, the resistor network <NUM> drops the line voltage (Vsource) by a large factor dependent on the source line voltage. For example, using three <NUM> KΩ resistors RA, RB and Rc and a transformer <NUM> with a <NUM>:<NUM> turns ratio, a 15kV single phase line voltage or <NUM>. 66kV, may be dropped by a factor ranging between about <NUM> kV to about <NUM>. 5kV across the parallel resistor network <NUM>. The voltage drop factor may range from about <NUM>-<NUM>% of the single phase source voltage. Further, since the parallel resistor network <NUM> is connected in series with the primary winding 24a of the transformer <NUM>, the parallel resistor network <NUM> is subjected to and configured to handling a high continuous wattage. The wattage is dependent upon a number of factors including the inductor size and construction, e.g., parallel configuration. As an example, the high continuous wattage may be in the range of between about 20W to about 100W. However, this wattage may change dependent on the line voltage and the output requirements of the circuit. As a non-limiting example, for a single-phase line voltage of <NUM> kV the high continuous wattage may be about 60W.

Claim 1:
A voltage harvesting device (<NUM>) for use in power distribution systems, characterized by the voltage harvesting device comprising:
a housing (<NUM>); and
a transformation circuit (<NUM>) within the housing, the transformation circuit including at least one first impedance component (<NUM>) and at least one second impedance component (<NUM>), the at least one first impedance component (<NUM>) having:
a positive input capable of being electrically coupled to a loaded or unloaded source line voltage;
a negative input electrically coupled to the at least one second impedance component (<NUM>); and
an output capable of being coupled to a device, wherein the output and the device both reference a floating ground of the loaded or unloaded source line voltage;
wherein the first impedance component (<NUM>) and the second impedance component (<NUM>) are arranged as a voltage divider, the voltage divider producing an AC voltage on the output of the first impedance component (<NUM>) that is a higher voltage than the loaded or unloaded source line voltage.