Electrical circuit for energy harvesting and electric machine sensing

Abstract

A system or device including a switch device, electromagnetic (EM) inductive device, energy harvester, at least one sensing device, and a controller. The EM inductive device generates an induced electrical voltage in response to an electromagnetic field from an AC electrical machine. The at least one sensing device determines at least one operational parameter of the AC electrical machine during a measurement interval of the induced electrical voltage. The controller is electrically connected with the energy harvester and controls switch device to selectively switch between the energy harvester and the at least one sensing device to enable measuring the electrical voltage and determining the at least one operational parameter of the AC electrical machine. The system may also include an energy storage device that powers the controller during a measurement interval when the switch device connects the EM inductive device to the at least one sensing device.

Description

ELECTRICAL CIRCUIT FOR ENERGY HARVESTING AND ELECTRIC MACHINE SENSINGFIELD

[0001] The present disclosure relates to the field of AC electrical machines. More particularly, to an electrical device for energy harvesting and electrical machine sensingBACKGROUND

[0002] AC electrical machines such as, for example, motors and generators are used in a wide range of applications such as, for example, in industrial systems such as heating, ventilation, and cooling systems and in power distribution systems for a facilities infrastructure. The reliability of such AC electrical machines may be important due to the high efficiency requirements and safety-critical nature of such industrial systems, particularly in the oil & gas, food and beverage, (discrete) manufacturing, and pharmaceutical industries. The AC electrical machines oftentimes include one or more electrically powered auxiliary devices coupled to the electrical machine. An energy source is used to power the auxiliary device. Commonly, batteries are used for this purpose.SUMMARY

[0003] Conventional auxiliary devices for electric machines can include a component located in the AC electrical machine for measuring a parameter of the AC electrical machine and may be powered from an external source. For example, the auxiliary device may include a sensor device for monitoring one or more rotating members in the AC electrical machine to determine a load or phase imbalance. In another example, the auxiliary device may include a sensor device for measuring a temperature inside the AC electrical machine. These conventional auxiliary devices may utilize a battery to power the controller. However, batteries have a limited lifetime as their efficiency and performance can decrease over time due touse, wear, environmental conditions, and other factors. Batteries can also be costly to replace, and the manufacturing and disposal of batteries can have adverse environmental effects.

[0004] Various embodiments of the present disclosure are directed to auxiliary devices configured to be placed in connection with electrical machines, the electrical machine producing an electromagnetic (EM) field as a result of one or more rotating components therein. In particular, the one or more embodiments described herein include a means for powering auxiliary devices using the EM field generated by the AC electrical machine and without needing a battery to power the auxiliary device, e.g., when measuring a parameter of the AC electrical machine, as will be further described herein.

[0005] In some embodiments, a device includes a switch device, an electromagnetic (EM) inductive device, the EM inductive device is in electrical connection with the switch device and the EM inductive device being configured to generate an induced electrical voltage in response to an electromagnetic field from an AC electrical machine, an energy harvester, at least one sensing device, the at least one sensing device being configured to determine at least one operational parameter of the AC electrical machine based on the induced electrical voltage during a measurement interval, and a controller, the controller is in electrical connection with the energy harvester and controls a switching operation of the switch device to selectively switch between the energy harvester at a first position and the at least one sensing device at a second position for the measurement interval to obtain the at least one operational parameter of the AC electrical machine measured by the at least one sensing device.

[0006] In some embodiments, the EM inductive device is configured to connect with the energy harvester or the at least one sensing device based on the switching operation of the switch device.

[0007] In some embodiments, the EM inductive device does not connect to the energy harvester and the at least one sensing device at a same period of time.

[0008] In some embodiments, the device further includes an energy storage device, the energy storage device is in electrical connection with the energy harvester and thecontroller, and the energy storage device powers the controller during the measurement interval when the controller switches the switch device from the energy harvester to the at least one sensing device.

[0009] In some embodiments, the energy storage device includes a bridge capacitor, the bridge capacitor includes at least one capacitor, and the bridge capacitor is configured to power the controller within an operating voltage range during the measurement interval.

[0010] In some embodiments, the at least one sensing device includes a bridge circuit including a set of resistors, and a sense coil, the bridge circuit is configured to produce a differential voltage for sensing the at least one operational parameter during the measurement interval.

[0011] In some embodiments, the bridge circuit is configured to produce the differential voltage to enable sensing a temperature at the AC electrical machine during the measurement interval.

[0012] In some embodiments, the sense coil may include one or more capacitors or one or more inductive components to enable the bridge circuit to create the differential voltage for sensing the temperature at the AC electrical machine during the measurement interval.

[0013] In some embodiments, the EM inductive device may be an auxiliary coil winding.

[0014] In some embodiments, an analog signal conditioning circuit converts and filters the sensing signal to acceptable range for further signal processing in the controller.

[0015] In some embodiments, the EM inductive device includes an air gap coil winding located between a rotor and a stator of the AC electrical machine.

[0016] In some embodiments, the EM inductive device includes an in-slot auxiliary winding.

[0017] In some embodiments, the at least one sensing device includes an analog-to- digital (AD) converter, the AD converter is in electrical connection with the switch device at the second position and in electrical connection with the controller, the AD converter transforms the induced electrical voltage to a digital signal as output.

[0018] In some embodiments, the controller obtains the digital signal and predicts a load or phase imbalance at the AC electrical machine.

[0019] In some embodiments, a system includes a multi-pole switch device, an EM inductive device, the EM inductive device is in electrical connection with the multipole switch device, and the EM inductive device is configured to generate an induced electrical voltage in response to an EM field from an AC electrical machine, an energy harvester, at least one sensing device, and a controller, the controller is in electrical connection with the energy harvester and controls a switching operation of the multi-pole switch device to selectively switch between the energy harvester at a first position and the at least one sensing device at a second position for a measurement interval to obtain at least one operational parameter of the AC electrical machine measured by the at least one sensing device.

[0020] In some embodiments, the EM inductive device is configured to electrically connect with the energy harvester or the at least one sensing device based on the switching operation of the multi-pole switch device.

[0021] In some embodiments, the EM inductive device does not connect to the energy harvester and the at least one sensing device at a same period of time.

[0022] In some embodiments, the EM inductive device includes an air gap coil winding located between a rotor and a stator of the AC electrical machine.

[0023] In some embodiments, the EM inductive device includes an in-slot auxiliary winding.

[0024] In some embodiments, the at least one sensing device includes an analog-to- digital (AD) converter, the AD converter is in electrical connection with the multipole switch device at the second position and in electrical connection with the controller, and the AD converter transforms the induced electrical voltage to a digital signal as output, the controller obtains the digital signal and predicts a load or phase imbalance at the AC electrical machine.

[0025] In some embodiments, the at least one sensing device includes a bridge circuit, the bridge circuit configured to produce a differential voltage for sensing a temperature at the AC electrical machine during the measurement interval.

[0026] In some embodiments, the system includes a notification component including at least one of one or more light emitting diodes or a display device.

[0027] In some embodiments, a method for harvesting energy from an AC electric machine includes positioning, by a controller, a switch device to a first position to connect an EM inductive device to an energy harvester to power the controller using an induced electrical voltage from the EM inductive device, the EM inductive device generating the induced electrical voltage in response to an electromagnetic field from an AC electrical machine, positioning, by the controller, the switch device to one or more other switch positions to connect the EM inductive device to one or more sensing devices for a measurement interval, and processing, by the controller, measurement signals obtained from a sensing device of the one or more sensing devices and determining an operational characteristic of an AC electrical machine based on the measurement signals, and an energy storage device powers the controller during the measurement interval when the controller switches the switch device from the energy harvester to the one or more sensing devices.

[0028] In some embodiments, the method further includes predicting, by the controller, a load / phase imbalance at the AC electrical machine in response to switching the switch device to a second position, and the one or more sensing devices includes a first sensing device corresponding to an AD converter in electrical connection with the switch device at the second position.

[0029] In some embodiments, the method further includes predicting, by the controller, a temperature of the AC electrical machine in response to switching the switch device to a third position, and the one or more sensing devices further includes a second sensing device corresponding to a bridge circuit in electrical connection with the switch device at the third position.BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Some embodiments of the disclosure are herein described, by way of example only, with reference to the accompanying drawings. With specific reference now to the drawings in detail, it is stressed that the embodiments shown are by way of example and for purposes of illustrative discussion of embodiments of thedisclosure. In this regard, the description taken with the drawings makes apparent to those skilled in the art how embodiments of the disclosure may be practiced.

[0031] FIG. 1 is a schematic view illustrating a system, according to some embodiments.

[0032] FIG. 2A is an exposed side view illustrating a first non-limiting example of a portion of the system of FIG. 1 , according to some embodiments.

[0033] FIG. 2B is an exposed side view illustrating a second non-limiting example of a portion of the system of FIG. 1 , according to some embodiments.

[0034] FIG. 3 is a schematic diagram illustrating a portion of system, according to some embodiments.

[0035] FIG. 4 is a schematic diagram illustrating a system, according to some embodiments.

[0036] FIG. 5 is a schematic diagram illustrating a system, according to some embodiments.

[0037] FIG. 6 is a graphical diagram illustrating the system facilitating measuring an induced voltage, according to some embodiments.

[0038] FIG. 7 is a flow diagram illustrating a method, according to some embodiments.DETAILED DESCRIPTION

[0039] Various embodiments of the present disclosure relate to systems, devices, apparatus, and methods for using a single coil installed inside an AC electrical machine (e.g., AC electric machine) to harvest energy from the external magnetic flux generated by the machine and to enable measurement of one or more operational characteristics of the machine. The ability to use a single coil for both energy harvesting and electric machine sensing saves the cost of manufacturing and installing additional components. In addition, the improved configurations enable enhanced sensing capabilities of on-electric machine parameter detection using embedded systems.

[0040] The routing of the induced coil signal from a coil winding may be switchable between an energy harvester and one or more sensing components. The coil signal is routed to different parts of the electrical circuit (e.g., different electrical components) with a multi-pole switch device, according to some embodiments. Insome embodiments, the switch device may be a multi-pole switch device. In addition, a controller may be powered by the energy harvester and may control the routing of the coil signal by controlling a switching operation of the switch device between the energy harvester and the one or more sensing components. In some embodiments, the one or more sensing components may include an analog-to- digital (AD) converter. In other embodiments, the one or more sensing components may further include a bridge circuit. In some embodiments, the one or more sensing components may include the AD converter and the bride circuit. In some embodiments, the one or more sensing components may further include one or more other sensing components and the switch device may be operable to switch between each of the sensing components and the energy harvester.

[0041] Among those benefits and improvements that have been disclosed, other objects and advantages of this disclosure will become apparent from the following description taken in conjunction with the accompanying figures. Detailed embodiments of the present disclosure are disclosed herein; however, it is to be understood that the disclosed embodiments are merely illustrative of the disclosure that may be embodied in various forms. In addition, each of the examples given regarding the various embodiments of the disclosure which are intended to be illustrative, and not restrictive.

[0042] FIG. 1 is a schematic view illustrating a system 100, according to some embodiments. System 100 includes electromagnetic (“EM”) inductive device 102, switch device 104, energy harvester 106, sensing device 108, and controller 110. In some embodiments, system 100 may also include an AC electrical machine (not shown) and the EM inductive device 102 may be located in the AC electrical machine and generates an induced voltage in response to the electromagnetic field produced by the rotating components of the AC electrical machine.

[0043] System 100 may include a device 112 including one or more components of system 100 for harvesting energy and performing sensor measurements of one or more operational parameters indicative of a condition of the AC electrical machine (e.g., AC electric machine) based on an induced voltage in EM inductive device 102 produced as a result of the external magnetic flux from the one or more of therotating components of the AC machine (e g., rotor and stator). In some embodiments, the AC electrical machine and EM inductive device 102 may be externally located relative to system 100 and EM inductive device 102 may be in electrical connection with the components of system 100 through switch device 104. In some embodiments, EM inductive device 102 may be electrically connected to switch device 104 through an electrical conductor. The switch device 104 selectively places EM inductive device 102 in electrical connection with energy harvester 106 and the sensing device 108.

[0044] Device 112 may include EM inductive device 102, switch device 104, energy harvester 106, sensing device 108, controller 110, other components, or any combinations thereof. Device 112 may have a housing 114 and one or more of the components of device 112 may be located in the housing 114. In some embodiments, switch device 104, energy harvester 106, sensing device 108, controller 110, or any combinations thereof may be located in device 112 and / or within the housing 114 of device 112, and EM inductive device 102 may be located in the AC electrical machine and externally located relative to device 112 to produce the induced voltage resulting from the external magnetic flux generated from the rotating components of the AC machine. In some embodiments, device 112 may be located on the AC electrical machine. For example, the device 112 may be attached to an external surface of the AC electrical machine cover. In other embodiments, the device 112 may be located in the AC electrical machine. For example, the device 112 may be attached to an internal surface of the cover of the AC electrical machine.

[0045] The system 100 includes the EM inductive device 102. The EM inductive device 102 may be formed of an electromagnetically conductive material. EM inductive device 102 generates an electrical voltage induced in response to an external EM field applied to the EM inductive device 102. The EM field may be generated by rotating components of an AC electrical machine (e.g., rotor and stator). EM inductive device 102 is in electrical connection with switch device 104 to enable the electrical voltage (and electrical current) from EM inductive device 102 to bedirected to the energy harvester 106 and the sensing device 108 through switch device 104 based on the position of switch device 104.

[0046] The EM inductive device 102 is installed on or in the AC electrical machine. The EM inductive device 102 may be an in-air coil, in-slot winding, and other coil types for producing an induced voltage in response to an electromagnetic field. In some embodiments, the EM inductive device 102 may be an air gap coil winding located between a rotor and stator of the AC electric machine. In other embodiments, the EM inductive device 102 may be an in-slot auxiliary winding. The EM inductive device 102 may include a printed circuit board (PCB) configured to perform operations including, but not limited to, signal conditioning, signal boosting, filtering, and to provide the induced voltage to the other components of system 100 through switch device 104.

[0047] The EM inductive device 102 may include a printed circuit board (PCB) (not shown) configured to obtain the induced electrical current signal generated by the EM inductive device 102 and include one or more components therein for performing operations including, but not limited to, signal conditioning, signal boosting, filtering, and to output the processed electrical current signal to other components of system 100 such as, for example, energy harvester 106 through switch device 104. In some embodiments, the PCB may be located between the EM inductive device 102 and the switch device 104. In other embodiments, the PCB may be located in the device 112 such as, for example, within the housing 114 of device 112 and upstream of the switch device 104 such that the processed signal may be routed by the switch device 104 to each of the different components of device 112.

[0048] It is to be appreciated by those having ordinary skill in the art that the electrical voltage at EM inductive device 102 may be based on a plurality of factors including, but is not limited to, the speed of the rotating components, the number of turns to the coil, the strength of the EM field generating by the electrical machine, the diameter of the coil, the cross-section of the coil loops, other like factors, or any combinations thereof.

[0049] The system 100 includes the switch device 104. Switch device 104 selectively connects EM inductive device 102 between the energy harvester 106 and sensingdevice 108. Switch device 104 may include any of a plurality of electrical switching components including, but not limited to, relays, transistors, analog switches, other components, or any combinations thereof. For example, switch device 104 may include one or more low-power mechanical relays to enable switching between the different components of device 112. In another example, switch device 104 may include one or more analog switch integrated circuits to enable switching between the different components of device 112. The electrical switching components of switch device 104 are configured to enable the EM inductive device 102 to be connected to energy harvester 106 and to enable switch device 104 to switch between energy harvester 106 and the sensing device 108 of system 100.

[0050] Switch device 104 may be a multi-pole switch that selectively connects EM inductive device 102 to energy harvester 106 and sensing device 108 by switching between a first position A and a second position B, respectively. The switching operation of switch device 104 may be controlled by controller 110, as will be further described herein.

[0051] System 100 includes the energy harvester 106. The energy harvester 106 may include one or more electrical components configured to obtain the induced coil voltage and powering one or more components of system 100. The energy harvester 106 obtains the coil voltage when switch device 104 is positioned at the first position A connecting the EM inductive device 102 to energy harvester 106. The energy harvester 106 harvests the induced voltage of EM inductive device 102 and powers the controller 110, according to some embodiments. In other embodiments, the energy harvester 106 may also power an energy storage device (“ESD”) 116, as will be further described herein.

[0052] System 100 includes the sensing device 108. The sensing device 108 is connected between switch device 104 and controller 110. Sensing device 108 obtains the induced coil voltage from EM inductive device 102 (through switch device 104) and converts the induced voltage to a digital signal. The sensing device 108 outputs the measurement signal as a digital signal to controller 110, as will be further described herein. In some embodiments, the system 100 includes one sensing device 108. In other embodiments, the system 100 includes at least one sensingdevice 108. In yet other embodiments, the system 100 includes one or more sensing device 108. In some embodiments, sensing device 108 may be an analog- to-digital (“AD”) converter that converts the analog coil voltage to the digital signal to enable the controller 110 to determine a load or phase imbalance in the AC electrical machine. In other embodiments, sensing device 108 may include a bridge circuit for measuring the resistance of the coil to determine the temperature of the AC electrical machine.

[0053] It is to be appreciated by those having ordinary skill in the art that the number of sensing device 108 included in system 100, and as shown in FIG. 1 , is exemplary and is not intended to be limiting. Accordingly, the system 100 may include one or more sensing devices of one or more different types for measuring different operational parameters of the AC electrical machine, in accordance with the present disclosure.

[0054] System 100 may include controller 110. The controller 110 is in electrical connection with energy harvester 106 and sensing device 108 and includes a processor 118 and a memory 120. The memory 120 may be a non-transitory computer readable medium having stored thereon instructions executable by the processor 118 to perform operations in accordance with the present disclosure for controlling the switch device 104, energy harvester 106, and the sensing device 108 to harvest energy from the induced coil voltage of EM inductive device 102 and to measure the induced coil voltage and determine one or more operational parameters of the AC electrical machine.

[0055] The controller 110 may include a communication component 122 to enable the controller 110 to send and receive electronic signals corresponding to an operation of the controller 110, the one or more other components of device 112, the operational parameters of the AC electrical machine, or any combinations thereof, with an external computing device (not shown), according to various embodiments. In some embodiments, the communication component 122 may be a wireless communication component that may be placed in electronically communication connection with the external computing device through any of a plurality of wireless communication protocols including, but not limited to WiFi, Bluetooth, Zigbee,CDMA, 3G, 4G, 5G, LTE, Zigbee, other like protocols, or any combinations thereof. In some embodiments, the controller 110 may be capable of sending and receiving data to / from the external computing device through a network such as, for example, LAN, residential WiFi network, internet, other networks, and the like.

[0056] Although not shown in the figures, the device 112 may include an interface component in electronic communicable connection with controller 110. The interface component may include a notification component configured to provide one or more indications associated with device 112 including, but not limited to, a power state of device 112, switch position of switch device 104, condition of the electrical voltage measured by the sensing device 108 and / or controller 110, other parameters, or any combinations thereof. In some embodiments, the notification component may include one of one or more light emitting diodes viewable by a user of device 112. In other embodiments, the notification component may include a display viewable by the user of device 112. In yet other embodiments, the notification component may include one or more light emitting diodes and the display. In some embodiments, the controller 110 may include the interface component in electronic communicable connection with the notification component arranged for example, on the housing 114 of device 112.

[0057] Energy harvester 106 obtains the induced coil voltage from EM inductive device 102 and transforms the voltage to an appropriate level to power the controller 110 and to enable the controller 110 to control the switching operation of switch device 104 between a first position A (e.g., energy harvester 106) and a second position (e.g., sensing device 108). By connecting EM inductive device 102 to sensing device 108 using switch device 104, the sensing device 108 obtains the induced coil voltage from EM inductive device 102 and converts the coil voltage to the digital signal. The controller 110 obtains the digital signal from sensing device 108, and the controller 110 is configured to determine a load or phase imbalance of the AC electrical machine based on the digital signal. In this regard, controller 110 may also be in connection with sensing device 108 to obtain the converted digital signal from sensing device 108 a.

[0058] The system 100 may further include the ESD 116. Referring to FIG. 1 , the ESD 116 is in electrical connection with an input of the energy harvester 106 and the controller 110. The ESD 116 powers the controller 110 when the switch device 104 switches from the energy harvester 106 to the sensing device 108. In addition, the ESD 116 is configured to provide power to the controller 110 within an operating voltage range during a measurement interval of the sensing device 108 when the controller 110 switches the position of the switch device 104 to connect the EM inductive device 102 to the sensing device 108.

[0059] The ESD 116 is connected to the energy harvester 106 when the switch device 104 is in the first position A, thereby connecting the EM inductive device 102 to the energy harvester 106 to enable the ESD 116 to be charged with the power harvested by energy harvester 106 and while the energy harvester 106 powers the controller 110. ESD 116 is also connected to controller 110 to provide power to controller 110 for a period of time when controller 110 switches the switch device 104 from the first position A (e.g., energy harvester 106) to the second position B (e.g., sensing device 108), and the ESD 116 powers the controller 110 while the sensing device 108 measures the induced coil voltage from EM inductive device 102 and converts the analog coil voltage to the digital signal and outputs the digital signal to controller 110. Once controller 110 obtains the digital signal indicative of the load or phase imbalance at the AC electrical machine, the controller 110 switches the switch device 104 from the second position B to the first position A, to connect EM inductive device 102 back to energy harvester 106 to power the controller 110 with EM inductive device 102 and to charge the ESD 116.

[0060] The ESD 116 may be a capacitor, according to some embodiments. In some embodiments, the ESD 116 may be a bridge capacitor including one or more capacitors therein. For example, the bridge capacitor may include a capacitor on each of two legs. The ESD 116 may be configured to store a charge adequate to enable the controller 110 to switch the switch device 104 from the energy harvester 106 to the sensing device 108 and to enable the sensing device 108 to measure the AC coil voltage for signal measurement purposes, and to enable the controller110 to control the switch device 104 to switch from the second position B back to the first position A.

[0061] FIG. 2A is an exposed side view illustrating a first non-limiting example of a portion of system 100 of FIG. 1 , according to some embodiments. FIG. 2B is an exposed side view illustrating a second non-limiting example of a portion of system 100 of FIG. 1 , according to some embodiments.

[0062] The system 100 includes the EM inductive device 102. The EM inductive device 102 may include any of a plurality of inductive devices including, but is not limited to, an in-air coil, in-slot winding, or other coil types that are capable of producing an induced electrical current in response to the electromagnetic field from the AC electrical machine 124. The EM inductive device 102 may be located in an AC electrical machine such as AC electrical machine 124, according to various embodiments.

[0063] In addition, the AC electrical machine 124 may be an AC motor, in some embodiments. In other embodiments, the AC electrical machine 124 may be an AC generator. It is to be appreciated by those having ordinary skill in the art that the AC electrical machine 124 is not intended to be limited to AC motors and generators and may include any of a plurality of electrical machines capable of generating an EM field where the EM inductive device 102 may be capable of generating an induced electrical current in response to the EM field suitable for performing the operations in accordance with the present disclosure.

[0064] AC electrical machine 124 may include stator 126 and rotor 128, and AC electrical machine 124 may further include a plurality of slots 130 and a plurality of teeth 132 circumferentially arranged between the stator 126 and rotor 128 configured to accommodate the armature windings of the AC electrical machine 124. For example, an inner circumference of a stator may include a plurality of teeth radially extending inward toward a central axis of the rotor and may further include a slot between each tooth.

[0065] Referring to FIG. 2A, the EM inductive device 102 may be an in-slot auxiliary winding. The AC electrical machine 124 may include a plurality of the slots 130 located between the rotating components therein. In some embodiments, the EMinductive device 102 may be installed in one of the slot 130 of stator 126 at the AC electrical machine 124. In some embodiments, the EM inductive device 102 may be an air gap coil winding located in a slot 130 of the stator 126. In other embodiments, the EM inductive device 102 may be an air gap coil winding located in a slot between two teeth at an outer circumference of the rotor 128.

[0066] Referring to FIG. 2B, the EM inductive device 102 may be an air gap harvesting coil. The EM inductive device 102 may be installed between the stator 126 and rotor 128 in an air gap defined by the space between an outer circumference of the rotor 128 and an inner circumference of the stator 126, according to some embodiments.

[0067] FIG. 3 is a schematic diagram illustrating a portion of system 100, according to some embodiments.

[0068] According to some embodiments, the sensing device 108 may be a bridge circuit 134. The bridge circuit may be connected to a signal conditioning circuit and to controller 110. The signal conditioning circuit may obtain the induced electrical current from EM inductive device 102 and may output the conditioned signal to bridge circuit 134. The bridge circuit 134 may obtain the conditioned signal and may convert the obtained conditioned electrical current signal to a differential voltage during the measurement interval. The controller 110 may obtain the differential voltage from the bridge circuit 134 during the measurement interval to determine at least one operational parameter indicative of a monitoring state of the AC electrical machine, as will be further described herein.

[0069] The bridge circuit 134 may include legs 136 a, 136 b, 136 c, 136 d, hereinafter referred to legs 136, and having arranged thereon a set of resistors 138 and sense coil 140. In some embodiments, the set of resistors 138 may be located at legs 136 a, 136 b, 136 c and sense coil 140 may be located at leg 136 d. In other embodiments, the bridge circuit 134 may include a set of resistors 138 including resistor 138 a located at leg 136 a, resistor 138 b located at leg 136 b, resistor 138 c located at leg 136 c, and sense coil 140 located at leg 136 d.

[0070] The bridge circuit 134 may be configured to produce a differential voltage, in response to the induced electrical current routed from EM inductive device 102through switch device 104, for sensing at least one operational parameter during the measurement interval when the switch device 104 connects the EM inductive device 102 to the sensing device 108. In some embodiments, differential voltage produced by the bridge circuit 134 may be indicative of a temperature at the AC electrical machine during the measurement interval. In some embodiments, the bridge circuit 134 may include terminal 142 and terminal 144 configured to enable measuring a differential voltage across the bridge circuit 134 to determine an operational parameter of the AC electrical machine, such as AC electrical machine 124 in FIG. 2A. In some embodiments, the controller 110 may be in electrical connection with the bridge circuit 134 at terminal 142 and terminal 144 and the controller 110 may determine the operational parameter of the AC electrical machine based on the measured differential voltage at the bridge circuit 134.

[0071] The bridge circuit 134 may be configured to measure one or more operational parameters of the AC electrical machine. In some embodiments, the set of resistors 138 and sense coil 140 may be configured to enable measuring one or more operational parameters of the AC electrical machine. For example, the bridge circuit 134 may include one or more variable resistors (e.g., varistors) that may be configured by controller 110 to enable measuring one or more operational parameters. In other embodiments, the system 100 may include one or more of the bridge circuit 134, each of the bridge circuit 134 configured to measure a different operational parameter of the AC electrical machine, in accordance with the present disclosure.

[0072] It is to be appreciated by those having ordinary skill in the art that although FIG. 3 illustrates an inductive coil in sense coil 140, FIG. 3 is not intended to be limiting and the bridge circuit 134 may include any of a plurality of components including, but not limited to, capacitors, inductive components (e.g., inductors), other components, or any combinations thereof. In some embodiments, the sense coil 140 may include one or more capacitors to enable the bridge circuit 134 to create the differential voltage for sensing the temperature at the AC electrical machine during the measurement interval. In other embodiments, the sense coil 140 may include one or more inductive components to enable the bridge circuit 134 tocreate the differential voltage for sensing the temperature at the AC electrical machine during the measurement interval.

[0073] FIG. 4 is a schematic diagram illustrating a system 200, according to some embodiments.

[0074] System 200 includes coil winding 202 and device 212. Device 212 includes switch device 204, energy harvester 206, sensing device 208 a, sensing device 208 b, and controller 210. In some embodiments, device 212 may include one or more other additional components for harvesting energy and performing sensor measurements of one or more parameters indicative of an operating condition of the AC electrical machine (e.g., AC electric machine) determined based on the external magnetic flux generated by the one or more of the rotating components of the AC machine (e.g., rotor and stator). In some embodiments, system 200 may also include the AC electrical machine (not shown) and the coil winding 202 may be located in the AC electrical machine and generates an induced voltage in response to the electromagnetic field produced by the rotating components of the AC electrical machine.

[0075] In some embodiments, the AC electrical machine and coil winding 202 may be externally located relative to system 200 and coil winding 202 may be in electrical connection with the components of system 200 through switch device 204. In some embodiments, Coil winding 202 may be electrically connected to switch device 204 through an electrical conductor. The switch device 204 selectively places the coil winding 202 in electrical connection with energy harvester 206, sensing device 208 a, and sensing device 208 b.

[0076] Referring to FIG. 4, device 212 includes coil winding 202, switch device 204, energy harvester 206, sensing device 208 a, sensing device 208 b, and controller 210. In some embodiments, device 212 may include a housing 214 and one or more of the components of device 212 may be located in the housing 214. The switch device 204, energy harvester 206, sensing device 208 a, sensing device 208 b, controller 210, or any combinations thereof, may be located in the housing 214, according to some embodiments. In addition, in some embodiments, coil winding 202 may be located in the AC electrical machine and externally locatedrelative to housing 214 to generate the induced voltage in response to the external magnetic flux from the rotating components of the AC machine being applied to the coil winding 202. In some embodiments, device 212 may be located on the AC electrical machine. For example, the device 212 may be attached to an external surface of the AC electrical machine cover. In other embodiments, the device 212 may be located in the AC electrical machine. For example, the device 212 may be attached to an internal surface of the cover of the AC electrical machine.

[0077] The system 200 includes the coil winding 202. The Coil winding 202 may be formed of an electromagnetically conductive material. Coil winding 202 generates an electrical voltage induced in response to an external EM field applied to the coil winding 202. The EM field may be generated by rotating components of an AC electrical machine (e.g., rotor and stator). Coil winding 202 is in electrical connection with switch device 204 to enable the electrical voltage (and electrical current) from coil winding 202 to be directed to the energy harvester 206 and the sensing device 208 through switch device 204 based on the position of switch device 204.

[0078] Coil winding 202 may be installed on or in the AC electrical machine, according to some embodiments. Coil winding 202 may be an in-air coil, in-slot winding, and other coil types for producing an induced voltage in response to an electromagnetic field. In some embodiments, the coil winding 202 may be an air gap coil winding located between a rotor and stator of the AC electric machine. In other embodiments, the coil winding 202 may be an in-slot auxiliary winding. The coil winding 202 may include a printed circuit board (PCB) configured to perform operations including, but not limited to, signal conditioning, signal boosting, filtering, and to provide the induced voltage to the other components of system 100 through switch device 204.

[0079] It is to be appreciated by those having ordinary skill in the art that the electrical voltage induced at coil winding 202 may be based on a plurality of factors including, but is not limited to, the speed of the rotating components, the number of turns to the coil, the strength of the EM field generating by the electrical machine, the diameter of the coil, the cross-section of the coil loops, other like factors, or anycombinations thereof. It is also to be appreciated by those having ordinary skill in the art that the system 200 as shown in FIG. 4 is exemplary and not intended to be limiting and the system 200 is thereby not intended to be limited to a coil winding such as, for example, coil winding 202 and may include other types of devices capable of generating an induced electrical signal in response to an external electromagnetic field produced by the AC electrical machine.

[0080] The system 200 includes the switch device 204. Switch device 204 selectively connects coil winding 202 between the energy harvester 206, sensing device 208 a, and sensing device 208 b. Switch device 204 may include any of a plurality of electrical switching components including, but not limited to, relays, transistors, analog switches, electrical contacts, other components, or any combinations thereof. For example, switch device 204 may include one or more low-power mechanical relays to enable switching between the different components of device 212. In another example, switch device 204 may include one or more analog switch integrated circuits to enable switching between the different components of device 212. The electrical switching components of switch device 204 are configured to enable the coil winding 202 to be connected to energy harvester 206 and to enable switch device 204 to switch between energy harvester 206, sensing device 208 a, and sensing device 208 b.

[0081] Switch device 204 may be a multi-pole switch that selectively connects coil winding 202 to one or more devices. The switching operation of switch device 204 may be controlled by controller 210. As shown in FIG. 4, the switch device 204 can electrically connect coil winding 202 with the energy harvester 206, sensing device 208 a, and sensing device 208 b by switching between each switch position. In some embodiments, the switch device 204 can switch to a first position A to connect the coil winding 202 with energy harvester 206, a second position B to connect the coil winding 202 with sensing device 208 a, and to a third position C to connect the coil winding 202 with sensing device 208 b. In other embodiments, the sensing device 208 a and sensing device 208 b can be connected to a single switch position (e.g., position B) and the switch device 204 switching to the respective switch position may connect the coil winding 202 to both the sensingdevice 208 a and sensing device 208 b. It is to be appreciated by those having ordinary skill in the art that the configuration of the switch device 204 is not intended to be limiting and that the one or more components of device 212 and the coil winding 202 may be in electrical connection with any of the plurality of positions in the switch device 204 in accordance with the present disclosure.

[0082] System 100 includes the energy harvester 206. The energy harvester 206 may include one or more electrical components configured to obtain the induced coil voltage and powering one or more components of system 100. The energy harvester 206 obtains the coil voltage when switch device 204 is positioned at the first position A connecting the coil winding 202 to energy harvester 206. The energy harvester 206 harvests the induced voltage from coil winding 202 and powers the controller 210, according to some embodiments. In other embodiments, the energy harvester 206 may also power an energy storage device (“ESD”) 216, as will be further described herein.

[0083] System 200 includes the sensing device 208 a and sensing device 208 b, which may hereinafter be referred to as sensing devices 208. The sensing devices 208 in device 212 may include any of a plurality of measurement devices configured to measure the induced coil voltage from coil winding 202 to determine an operational parameter of the AC electrical machine, according to some embodiments. In other embodiments, the sensing devices 208 may measure one or more other operational parameters of the AC electrical machine. In other embodiments, the sensing devices 208 may measure the coil voltage of the coil winding 202 and generate an output signal to controller 210 to enable controller 210 to determine the one or more operational parameters of the AC electrical machine based on the obtained signals. In some embodiments, the sensing devices 208 in device 212 may be capable of measuring a plurality of operational parameters of the AC electrical machine including, but not limited to, current, voltage, frequency, load / phase, power, vibration, speed, electromagnetic field (EMF), other parameters, or any combinations thereof. For example, the sensing devices 208 may include an AD converter for measuring a load imbalance at the AC electric machine. In another example, the sensing devices 208 may include a bridge circuitfor measuring the resistance of the coil to determine the temperature of the AC electrical machine. In some embodiments, the system 200 includes one of sensing device 208 a and one of sensing device 208 b. In other embodiments, the system 200 may include a plurality of sensing device 208 a and / or a plurality of sensing device 208 b.

[0084] The sensing device 208 a is connected between switch device 204 and controller 210. Sensing device 208 a obtains the induced coil voltage from coil winding 202 (through switch device 204) and converts the induced voltage to a digital signal for determining an operational parameter of the AC electrical machine. In some embodiments, the sensing device 208 a outputs the measurement signal as a digital signal to controller 210, as will be further described herein. For example, the sensing device 208 a may send digital signals as output to the controller 210 to enable the controller 210 to determine a load or phase imbalance of the AC electric machine and sensing device 208 b may determine a temperature at the AC electric machine. In some embodiments, sensing device 208 a may be an analog-to-digital (“AD”) converter that converts the analog coil voltage to the digital signal to enable the controller 210 to determine a load or phase imbalance in the AC electrical machine and sensing device 208 b may be a bridge circuit for measuring resistance of the coil winding 202 to infer the temperature inside the AC electrical machine.

[0085] The sensing device 208 b is also connected to the switch device 204. The sensing device 208 b obtains the induced coil voltage from coil winding 202 (through switch device 204) and may be utilized to determine one or more operational parameters of the AC electrical machine. In some embodiments, the sensing device 208 b may be a bridge circuit that may, based on the induced coil voltage from coil winding 202, produce a differential voltage that may be measurable across the sensing device 208 b for sensing the operational parameters during a measurement interval when the switch device 204 is switched to sensing device 208 b. In some embodiments, the controller may be capable of determining at least one operational parameter based on the measurement of the sensing device 208 b. In other embodiments, the controller may be capable of determining one or moredifferent operational parameters based on the measurement of the sensing device 208 b.

[0086] In addition, in some embodiments, the sensing device 208 b may output the measurement signal as a digital signal to controller 210 similar to sensing device 208 a, as will be further described herein. In some embodiments, the sensing device 208 a may cooperate with the controller 210 to determine a first operational parameter and the sensing device 208 b may determine a second operational parameter. In some embodiments, the sensing device 208 b may be a bridge circuit. The bridge circuit may include, but is not limited to, a Wheatstone bridge, Maxwell bridge, Kelvin bridge, Maxwell-Wien bridge, other bridge circuits, or any combinations thereof. In some embodiments, the resistance of the induced coil voltage measured by sensing device 208 b (e.g., bridge circuit) may be used to predict (e.g., infer) the temperature inside the AC electrical machine. In some embodiments, the controller 210 may obtain the resistance of the coil and may determine the temperature of the AC electrical machine based on the resistance. Similar to sensing device 208 a, the controller 210 may obtain digital output signals from sensing device 208 b to enable the controller 210 to determine one or more measured operational parameters. For example, the controller 210 may determine the temperature at the AC electric machine is exceeding a certain threshold based on the output from sensing device 208 b.

[0087] It is to be appreciated by those having ordinary skill in the art that the number and / or type of sensing devices 208 in system 200 is not intended to be limiting and system 200 may include one or more different types of sensing devices 208 in accordance with the present disclosure. Furthermore, it is to be appreciated by those having ordinary skill in the art that the number of switch positions of switch device 204 may be based, at least in part, on a number of sensing devices 208 in electrical connection with the switch device 204, in accordance with the present disclosure.

[0088] It is to be appreciated by those having ordinary skill in the art that the number of sensing device 208 included in system 200, and as shown in FIG. 1 , is exemplary and is not intended to be limiting. Accordingly, the system 200 may include one ormore sensing devices of one or more different types for measuring different operational parameters of the AC electrical machine, in accordance with the present disclosure.

[0089] System 200 may include controller 210. The controller 210 is in electrical connection with energy harvester 206 and sensing device 208. Although not shown in the figures, controller 210 may include a processor 218 and a memory 220. The memory 220 may be a non-transitory computer readable medium having stored thereon instructions executable by the processor 218 to perform operations in accordance with the present disclosure for controlling the switch device 204 to connect the coil winding 202 to the energy harvester 206 to harvest energy from the induced coil voltage of coil winding 202 and sensing device 208 connects the coil winding 202 to sensing device 208 a or sensing device 208 b to measure the induced coil voltage and determine one or more respective operational parameters of the AC electrical machine.

[0090] Energy harvester 206 obtains the induced coil voltage from coil winding 202 and transforms the voltage to an appropriate level to power the controller 210 and to enable the controller 210 to control the switching operation of switch device 204 between the first position A (e.g., energy harvester 206), second position B (e.g., sensing device 208 a), and third position C (e.g., sensing device 208 b). By connecting coil winding 202 to one of the sensing devices 208 using switch device 204, the respective one of sensing devices 208 obtains the induced coil voltage from coil winding 202 and utilizes the induced voltage to determine one or more operational parameters associated with the AC electrical machine. In some embodiments, the sensing device 208 may convert the coil voltage to a digital signal provided as output, and the controller 210 may obtain the digital signal from the respective sensing device 208 and determines the operational parameter. In some embodiments, the operational parameter may include a load or phase imbalance of the AC electrical machine based on the digital signal. In other embodiments, the operational parameter may include a temperature of the AC electrical machine. In this regard, controller 210 may also be in connection with one or more of the sensing devices 208 to obtain the converted digital signal(s)from the sensing device 208 and to enable determining the operational parameter based on the signals obtained from the sensing device 208.

[0091] The system 100 may further include the ESD 216. Referring to FIG. 4, the ESD 216 is in electrical connection with an input of the energy harvester 206 and the controller 210. The ESD 216 powers the controller 210 when the switch device 204 switches from the energy harvester 206 to the sensing device 208. In addition, the ESD 216 is configured to provide power to the controller 210 within an operating voltage range during a measurement interval of the sensing devices 208 when the controller 210 switches the position of the switch device 204 to connect the coil winding 202 to the respective one of the sensing devices 208.

[0092] The ESD 216 is connected to the energy harvester 206 when the switch device 204 is in the first position A, thereby connecting the coil winding 202 to the energy harvester 206 and to enable the ESD 216 to be charged with the power harvested by energy harvester 206. ESD 216 may also be in electrical connection with controller 210 to provide power to controller 210 for a period of time when controller 210 switches the position of switch device 204 from the first position A (e.g., energy harvester 206) to another position such as, for example, the second position B (e.g., sensing device 208 a). When the controller 210 controls the switch device 204 to switch away from the first position A, the ESD 216 powers the controller 210 while the sensing device 208 in electrical connection with the coil winding 202 measures the induced coil voltage for determining the one or more operational parameters in accordance with the present disclosure. After a period of time, e.g., the controller 210 obtains the digital signal, the controller 210 controls the switching operation of switch device 204 to switch from the second position B back to the first position A, to connect coil winding 202 back to energy harvester 206 to power the controller 210 and to charge the ESD 216. In some embodiments, the controller 210 may control the switch device 204 to switch back to the first position A after a first period of time corresponding to when the controller 210 obtains the digital signals from the one of the sensing device 208 connected to the coil winding 202. In other embodiments, the controller 210 may further control the switch device 204 to switch back to the first position A after a second period of time corresponding towhen the ESD 216 is substantially discharged even if the controller 210 does not obtain the digital signals from the sensing device 208. The second period of time ensures that the controller 210 does not lose power in situations where the controller 210 may not receive the digital signals from the sensing device 208 before the ESD 216 is fully discharged, such that the controller 210 can control the switching operation of switch device 204 to switch back to the first position A.

[0093] The ESD 216 may be a capacitor, according to some embodiments. Although not shown in the figures, in some embodiments, the ESD 216 may be a bridge capacitor including one or more capacitors on each of the legs. For example, the bridge capacitor may include a capacitor on each of two legs. The ESD 216 may be configured to store a charge adequate to enable the controller 210 to switch the switch device 204 from the energy harvester 206 to the sensing device 208 and to enable the sensing device 208 to measure the AC coil voltage for signal measurement purposes, and to enable the controller 210 to control the switch device 204 to switch from the second position back to the first position.

[0094] FIG. 5 is a schematic diagram illustrating a system 300, according to some embodiments.

[0095] System 300 includes coil winding 302, switch device 304, energy harvester 306, controller 310, and ESD 316. System 300 also includes sensing device 308 a, sensing device 308 b, and through sensing device 308 n, which may hereinafter be referred to as sensing devices 308. The sensing devices 308 are configured to measure the induced coil voltage signal of coil winding 302 as a result of switch device 304 being positioned by controller 310 to connect the coil winding 302 with the respective one of the sensing device 308 (e.g., sensing device 308 a through sensing device 308 n). Based on the position of switch device 304, the sensing device 308 connected with the switch device 304 at the respective switch position measures the induced coil voltage of coil winding 302 and provides a respective output measurement signal corresponding to one or more operational parameters (e.g., health) of the AC electrical machine. In some embodiments, the sensing device 308 outputs the measurement signal to controller 310 to enable thecontroller 310 to determine the one or more operational parameters (e.g., health) of the AC electrical machine.

[0096] At the first position, switch device 304 connects coil winding 302 with energy harvester 306. Referring to FIG. 5, switch device 304 includes a second position, a third position, and through an nth position, and the switch device 304 connects the coil winding 302 between the energy harvester 306 and each of the sensing devices 308 by switching between the different positions. At the second position, switch device 304 may connect coil winding 302 to sensing device 308 a. At the third position, switch device 304 may connect coil winding 302 to sensing device 308 b. At the nth position, the switch device 304 may connect coil winding 302 to sensing device 308 n. In this regard, controller 310 controls the switching operation of switch device 304 and selectively switches between the first position through the nth position, and each position therebetween, to selectively connect the coil winding 302 between the energy harvester 306 and sensing device 308 a through sensing device 308 n, and each sensing device 308 therebetween.

[0097] The sensing devices 308 may include any of a plurality of measurement devices configured to measure the induced coil voltage and to determine an operational parameter of the AC electrical machine. In some embodiments, the sensing devices 308 measure the induced coil voltage and determines the operational parameters of the AC electrical machine. In other embodiments, the sensing devices 308 measure the coil voltage of the coil winding 302 and generates an output signal to controller 310 to enable controller 310 to determine the operational parameters of the AC electrical machine.

[0098] In some embodiments, the sensing devices 308 may include the AD converter. In other embodiments, the sensing device 308 may include a bridge circuit for measuring the resistance of the coil. In some embodiments, the bridge circuit may include, but is not limited to, a Wheatstone bridge, Maxwell bridge, Kelvin bridge, Maxwell-Wien bridge, other bridges, or any combinations thereof. In addition, the resistance of the induced coil voltage measured by the sensing device 308 (e.g., bridge circuit) may be used to infer the temperature inside the AC electrical machine. In some embodiments, the controller 310 may obtain the resistance ofthe coil and may determine the temperature of the AC electrical machine based on the resistance.

[0099] It is to be appreciated by those having ordinary skill in the art that the number of sensing devices 308 in system 300 is not intended to be limiting, and the system 100 may include one or more different types of sensing device 308 in accordance with the present disclosure. Furthermore, it is to be appreciated by those having ordinary skill in the art that the number of switch positions of switch device 304 may correspond to a number of the sensing device 308 in system 300, in accordance with the present disclosure.

[0100] FIG. 6 is a graphical diagram 600 illustrating the system 100 facilitating measuring an induced voltage, according to some embodiments.

[0101] In FIG. 6, one full cycle of an induced voltage 602 at an EM inductive device such as, for example, an EM inductive device 102 of FIG. 1 is illustrated. The controller 110 may control the switching of switch device 104 to switch from the energy harvester 106 to the sensing device 108 for a period of time 604. During the time period 504, the sensing device 108 samples the induced voltage 602 routed through the switch device 104 and provides an output signal to the controller 110. Based on obtaining the output signal from the sensing device 108, the controller 110 switches the switch device 104 from the respective position connecting EM inductive device 102 to the sensing device 108 and back to the first position to connect the EM inductive device 102 to energy harvester 106.

[0102] It is to be appreciated by those having ordinary skill in the art that the coil voltages of EM inductive device 102 and the length of the cycle is not intended to be limiting and the coil voltage and / or the length of the cycle may be greater than or less than the values illustrated in FIG. 4.

[0103] FIG. 7 is a flow diagram illustrating a method 700, according to some embodiments.

[0104] At 702, the method 700 includes positioning a switch device 104 to a first position to connect an EM inductive device 102 to the energy harvester 106 to power the controller 110 using an induced electrical voltage from the EM inductive device 102. The EM inductive device 102 generates the induced electrical voltagein response to an external electromagnetic field from an AC electrical machine applied to the EM inductive device 102. In some embodiments, the EM inductive device 102 may include an air gap coil winding. In other embodiments, the EM inductive device 102 may include an in-slot auxiliary winding. In yet other embodiments, the EM inductive device 102 may be any of a plurality of electrical devices known to persons of ordinary skill in the art capable of generating an induced electrical voltage in response to an electromagnetic field applied to the EM inductive device 102.

[0105] At 704, the method 700 includes positioning the switch device 104 to one or more other switch positions to connect the EM inductive device 102 to one or more sensing devices 108 for a measurement interval. Each sensing device 108 of the one or more sensing devices 108 measures the induced electrical voltage from EM inductive device 102 directed to the respective sensing device 108 through switch device 104 to determine one or more operational parameters of the AC electrical machine. In some embodiments, the sensing device 108 may act in cooperation with the controller 110 to determine the one or more operational parameters.

[0106] In this regard, at 706, the method 700 includes processing measurement signals obtained from a sensing device 108 of the one or more sensing devices such as, for example, sensing device 108 a through sensing device 108 n, and determining an operational characteristic of an AC electrical machine based on the measurement signals. In some embodiments, the sensing device 108 may convert the measured electrical voltage from EM inductive device 102 to an output signal indicative of the operational parameter of the AC electrical machine, and the controller 110 may obtain the output signal and determine and / or predict the one or more operational parameters of the AC electrical machine based on the signal obtained from the sensing device 108. For example, the operational parameter may include a load / phase imbalance at the Ac electrical machine. In another example, the operational parameter may include a temperature at the AC electrical machine.

[0107] In some embodiments, an energy storage device (ESD) 116 may be in electrical connection with the controller 110 and the energy harvester 106. The ESD 116 powers the controller 110 during the measurement interval when the controller 110 switches the switch device 104 from the energy harvester 106 to the switching device of the one or more sensing devices 108. When the switch device 104 is switched from the first position to the one or more other positions of switch device 104, the energy harvester 106 and the controller 110 is electrically disconnected from the EM inductive device 102 and the voltage power source. To enable the controller 110 to continue to control switching operation of the switch device 104 and to enable the controller 110 to obtain the output signal from the sensing device 108 connected to the EM inductive device 102 by the switch device 104, the ESD 116 powers the controller 110 during the measurement interval. Once the controller 110 obtains the measurement signal from the sensing device 108, the controller 110 switches the switch position of the switch device 104 back to the first position to reconnect the energy harvester 106 and the controller 110 (and ESD 116) with the EM inductive device 102.

[0108] In some embodiments, the ESD 116 may include a capacitor. In other embodiments, the ESD 116 may include a bridge capacitor including therein one or more capacitors. The capacitor(s) in the ESD 116 store an electrical charge when the energy harvester 106 is connected to the EM inductive device 102 and discharges when the switch device 104 switches from the first position to one of the other positions to provide power to the controller 110 during the measurement interval of the sensing device 108 associated with the respective position of switch device 104.

[0109] In some embodiments, the switch device 104 may be a multi-pole switch device including a plurality of positions, such that the switch device 104 may be controlled by controller 110 to selectively switch between the plurality of switch positions. The switch device 104 may include a first position A connected to the energy harvester 106. The switch device 104 may also include one or more other positions, e.g., positions B through N, each of the one or more other positions corresponding to other components that determines an operational parameter ofthe AC electrical machine in response to measuring the induced AC voltage from the EM inductive device 102.

[0110] In some embodiments, the one or more sensing devices 108 includes a first sensing device 108 a corresponding to an AD converter in electrical connection with the switch device 104 at the second position B. As such, in some embodiments, the method 700 may further include predicting a load / phase imbalance at the AC electrical machine in response to switching the switch device 104 to the second position B. In some embodiments, the controller 110 controls the switching of the switch device 104 to the second position B.

[0111] In some embodiments, the one or more sensing device 108 includes a sensing device 108 b corresponding to a bridge circuit in electrical connection with the switch device at a third position. As such, in some embodiments, the method 700 may further include predicting a temperature of the AC electrical machine in response to switching the switch device 104 to the third position. In addition, the EM inductive device 102 is configured to connect with the energy harvester 106 or one of the sensing device 108 based on the switch device 104 switching between each respective switch position. In this regard, the EM inductive device 102 does not connect to the energy harvester 106 and to one of the sensing device 108 at a same time (e.g., simultaneously). Instead, the controller 110 controls the switch position of the switch device 104 to connect the EM inductive device 102 to the one or more components of the device 112, e.g., energy harvester 106 or each of the sensing devices 108, sequentially.

[0112] All prior patents and publications referenced herein are incorporated by reference in their entireties.

[0113] Throughout the specification and claims, the following terms take the meanings explicitly associated herein, unless the context clearly dictates otherwise. The phrases "in one embodiment," “in an embodiment,” and "in some embodiments" as used herein do not necessarily refer to the same embodiment(s), though it may. Furthermore, the phrases "in another embodiment" and "in some other embodiments" as used herein do not necessarily refer to a differentembodiment, although it may. All embodiments of the disclosure are intended to be combinable without departing from the scope or spirit of the disclosure.

[0114] As used herein, the term "based on" is not exclusive and allows for being based on additional factors not described, unless the context clearly dictates otherwise. In addition, throughout the specification, the meaning of "a," "an," and "the" include plural references. The meaning of "in" includes "in" and "on."

[0115] As used herein, the term “between” does not necessarily require being disposed directly next to other elements. Generally, this term means a configuration where something is sandwiched by two or more other things. At the same time, the term “between” can describe something that is directly next to two opposing things. Accordingly, in any one or more of the embodiments disclosed herein, a particular structural component being disposed between two other structural elements can be: disposed directly between both of the two other structural elements such that the particular structural component is in direct contact with both of the two other structural elements; disposed directly next to only one of the two other structural elements such that the particular structural component is in direct contact with only one of the two other structural elements; disposed indirectly next to only one of the two other structural elements such that the particular structural component is not in direct contact with only one of the two other structural elements, and there is another element which juxtaposes the particular structural component and the one of the two other structural elements; disposed indirectly between both of the two other structural elements such that the particular structural component is not in direct contact with both of the two other structural elements, and other features can be disposed therebetween; or any combination(s) thereof.

[0116] As used herein “embedded” means that a first material is distributed throughout a second material.

[0117] ASPECTS

[0118] Various Aspects are described below. It is to be understood that any one or more of the features recited in the following Aspect(s) can be combined with any one or more other Aspect(s).

[0119] Aspect 1. A device comprising: a switch device, an electromagnetic (EM) inductive device, wherein the EM inductive device is in electrical connection with the switch device, the EM inductive device being configured to generate an induced electrical voltage in response to an electromagnetic field from an AC electrical machine; an energy harvester; at least one sensing device, wherein the at least one sensing device being configured to measure at least one operational parameter of the AC electrical machine based on the induced electrical voltage during a measurement interval; and a controller, wherein the controller is in electrical connection with the energy harvester and controls a switching operation of the switch device to selectively switch between the energy harvester at a first position and the at least one sensing device at a second position for the measurement interval to obtain the at least one operational parameter of the AC electrical machine measured by the at least one sensing device.

[0120] Aspect 2. The device according to aspect 1 , wherein the EM inductive device is configured to connect with the energy harvester or the at least one sensing device based on the switching operation of the switch device.

[0121] Aspect 3. The device according to any of the preceding aspects, wherein the EM inductive device does not connect to the energy harvester and the at least one sensing device at a same period of time.

[0122] Aspect 4. The device according to any of the preceding aspects, further comprising: an energy storage device, wherein the energy storage device is in electrical connection with the energy harvester and the controller, wherein the energy storage device powers the controller during the measurement interval when the controller switches the switch device from the energy harvester to the at least one sensing device.

[0123] Aspect 5. The device according to aspect 4, wherein the energy storage device comprises: a bridge capacitor, wherein the bridge capacitor includes at least one capacitor, and the bridge capacitor is configured to power the controller within an operating voltage range during the measurement interval.

[0124] Aspect 6. The device according to any of the preceding aspects, wherein the at least one sensing device comprises: a bridge circuit comprising: a set of resistors, and a sense coil, wherein the bridge circuit is configured to produce a differential voltage for sensing at least one operational parameter during the measurement interval.

[0125] Aspect 7. The device according to aspects 5 or 6, wherein the bridge circuit is configured to produce the differential voltage for sensing a temperature at the AC electrical machine during the measurement interval.

[0126] Aspect 8. The device according to any of the preceding aspects, wherein the EM inductive device comprises an air gap coil winding located between a rotor and a stator of the AC electrical machine.

[0127] Aspect 9. The device according to any of the preceding aspects, wherein the EM inductive device comprises an in-slot auxiliary winding.

[0128] Aspect 10. The device according to any of the preceding aspects, wherein the at least one sensing device comprises: an analog-to-digital (AD) converter, wherein the AD converter is in electrical connection with the switch device at the second position and in electrical connection with the controller, wherein the AD converter transforms the induced electrical voltage to a digital signal as output and the controller obtains the digital signal and predicts a load or phase imbalance at the AC electrical machine.

[0129] Aspect 11. A system comprising: a multi-pole switch device; an EM inductive device; wherein the EM inductive device is in electrical connection with the multi-pole switch device, and the EM inductive device is configured to generate an induced electrical voltage in response to an EM field from an AC electrical machine; an energy harvester; at least one sensing device, and a controller, wherein the controller is in electrical connection with the energy harvester and controls a switching operation of the multi-pole switch device to selectively switchbetween the energy harvester at a first position and the at least one sensing device at a second position for a measurement interval to obtain at least one operational parameter of the AC electrical machine measured by the at least one sensing device.

[0130] Aspect 12. The system according to aspect 11 , wherein the EM inductive device is configured to electrically connect with the energy harvester or the at least one sensing device based on the switching operation of the multi-pole switch device.

[0131] Aspect 13. The system according to aspects 11 or 12, wherein the EM inductive device does not connect to the energy harvester and the at least one sensing device at a same period of time.

[0132] Aspect 14. The system according to aspects 11 , 12, or 13, wherein the EM inductive device comprises an air gap coil winding located between a rotor and a stator of the AC electrical machine.

[0133] Aspect 15. The system according to aspects 11 , 12, 13, or 14, wherein the EM inductive device comprises an in-slot auxiliary winding.

[0134] Aspect 16. The system according to aspects 11 , 12, 13, 14, or 15, wherein the at least one sensing device comprises: an analog-to-digital (AD) converter, wherein the AD converter is in electrical connection with the multi-pole switch device at the second position and in electrical connection with the controller, wherein the AD converter transforms the induced electrical voltage to a digital signal as output, wherein the controller obtains the digital signal and predicts a load or phase imbalance at the AC electrical machine.

[0135] Aspect 17. The system according to aspects 11 , 12, 13, 14, 15, or 16, wherein the at least one sensing device comprises: a bridge circuit, wherein the bridge circuit is configured to produce the differential voltage for sensing a temperature at the AC electrical machine during the measurement interval.

[0136] Aspect 18. A method for harvesting energy from an AC electric machine comprising: positioning, by a controller, a switch device to a first position to connect an EM inductive device to an energy harvester to power the controller using an induced electrical voltage from the EM inductive device, the EM inductive devicegenerating the induced electrical voltage in response to an electromagnetic field from an AC electrical machine; positioning, by the controller, the switch device to one or more other switch positions to connect the EM inductive device to one or more sensing devices for a measurement interval; and processing, by the controller, measurement signals obtained from a sensing device of the one or more sensing devices and determining an operational characteristic of an AC electrical machine based on the measurement signals; wherein an energy storage device powers the controller during the measurement interval when the controller switches the switch device from the energy harvester to the one or more sensing devices.

[0137] Aspect 19. The method according to aspect 18, wherein the method further comprises: predicting, by the controller, a load / phase imbalance at the AC electrical machine in response to switching the switch device to a second position, wherein the one or more sensing devices comprises a first sensing device corresponding to an AD converter in electrical connection with the switch device at the second position.

[0138] Aspect 20. The method according to aspects 18 or 19, wherein the method further comprises: predicting, by the controller, a temperature of the AC electrical machine in response to switching the switch device to a third position, wherein the one or more sensing devices further comprises a second sensing device corresponding to a bridge circuit in electrical connection with the switch device at the third position.

[0139] It is to be understood that changes may be made in detail, especially in matters of the construction materials employed and the shape, size, and arrangement of parts without departing from the scope of the present disclosure. This Specification and the embodiments described are examples, with the true scope and spirit of the disclosure being indicated by the claims that follow.

Claims

CLAIMSWhat is claimed is:1 . A device comprising: a switch device, an electromagnetic (EM) inductive device, wherein the EM inductive device is in electrical connection with the switch device, the EM inductive device being configured to generate an induced electrical voltage in response to an electromagnetic field from an AC electrical machine; an energy harvester; at least one sensing device, wherein the at least one sensing device being configured to measure at least one operational parameter of the AC electrical machine based on the induced electrical voltage during a measurement interval; and a controller, wherein the controller is in electrical connection with the energy harvester and controls a switching operation of the switch device to selectively switch between the energy harvester at a first position and the at least one sensing device at a second position for the measurement interval to obtain the at least one operational parameter of the AC electrical machine measured by the at least one sensing device.

2. The device of claim 1 , wherein the EM inductive device is configured to connect with the energy harvester or the at least one sensing device based on the switching operation of the switch device.

3. The device of claim 2, wherein the EM inductive device does not connect to the energy harvester and the at least one sensing device at a same period of time.

4. The device of claim 1 , further comprising: an energy storage device, wherein the energy storage device is in electrical connection with the energy harvester and the controller, wherein the energy storage device powers the controller during the measurement interval when the controller switches the switch device from the energy harvester to the at least one sensing device.

5. The device of claim 4, wherein the energy storage device comprises: a bridge capacitor, wherein the bridge capacitor includes at least one capacitor, and the bridge capacitor is configured to power the controller within an operating voltage range during the measurement interval.

6. The device of claim 1 , wherein the at least one sensing device comprises: a bridge circuit comprising: a set of resistors, and a sense coil, wherein the bridge circuit is configured to produce a differential voltage for sensing at least one operational parameter during the measurement interval.

7. The device of claim 6, wherein the bridge circuit is configured to produce the differential voltage for sensing a temperature at the AC electrical machine during the measurement interval.

8. The device of claim 1 , wherein the EM inductive device comprises an air gap coil winding located between a rotor and a stator of the AC electrical machine.

9. The device of claim 1 , wherein the EM inductive device comprises an in-slot auxiliary winding.

10. The device of claim 1 , wherein the at least one sensing device comprises: an analog-to-digital (AD) converter, wherein the AD converter is in electrical connection with the switch device at the second position and in electrical connection with the controller, wherein the AD converter transforms the induced electrical voltage to a digital signal as output and the controller obtains the digital signal and predicts a load or phase imbalance at the AC electrical machine.

11. A system comprising: a multi-pole switch device; an EM inductive device; wherein the EM inductive device is in electrical connection with the multipole switch device, and the EM inductive device is configured to generate an induced electrical voltage in response to an EM field from an AC electrical machine; an energy harvester comprising: an energy storage device; at least one sensing device; and a controller, wherein the controller is in electrical connection with the energy harvester and controls a switching operation of the multi-pole switch device to selectively switch between the energy harvester at a first position and the at least one sensing device at a second position for a measurement interval to obtain at least one operational parameter of the AC electrical machine measured by the at least one sensing device.

12. The system of claim 11 , wherein the EM inductive device is configured to electrically connect with the energy harvester or the at least one sensing device based on the switching operation of the multi-pole switch device.

13. The system of claim 12, wherein the EM inductive device does not connect to the energy harvester and the at least one sensing device at a same period of time.

14. The system of claim 11 , wherein the EM inductive device comprises an air gap coil winding located between a rotor and a stator of the AC electrical machine.

15. The system of claim 11 , wherein the EM inductive device comprises an in-slot auxiliary winding.

16. The system of claim 11 , wherein the at least one sensing device comprises: an analog-to-digital (AD) converter, wherein the AD converter is in electrical connection with the multi-pole switch device at the second position and in electrical connection with the controller, wherein the AD converter transforms the induced electrical voltage to a digital signal as output, wherein the controller obtains the digital signal and predicts a load or phase imbalance at the AC electrical machine.

17. The system of claim 11 , wherein the at least one sensing device comprises: a bridge circuit, wherein the bridge circuit is configured to produce a differential voltage for sensing a temperature at the AC electrical machine during the measurement interval.

18. A method for harvesting energy from an AC electric machine comprising: positioning, by a controller, a switch device to a first position to connect an EM inductive device to an energy harvester to power the controller using an induced electrical voltage from the EM inductive device, the EM inductive device generating the induced electrical voltage in response to an electromagnetic field from an AC electrical machine;positioning, by the controller, the switch device to one or more other switch positions to connect the EM inductive device to one or more sensing devices for a measurement interval; and processing, by the controller, measurement signals obtained from a sensing device of the one or more sensing devices and determining an operational characteristic of an AC electrical machine based on the measurement signals; wherein an energy storage device powers the controller during the measurement interval when the controller switches the switch device from the energy harvester to the one or more sensing devices.

19. The method of claim 18, wherein the method further comprises: predicting, by the controller, a load / phase imbalance at the AC electrical machine in response to switching the switch device to a second position, wherein the one or more sensing devices comprises a first sensing device corresponding to an AD converter in electrical connection with the switch device at the second position.

20. The method of claim 19, wherein the method further comprises: predicting, by the controller, a temperature of the AC electrical machine in response to switching the switch device to a third position, wherein the one or more sensing devices further comprises a second sensing device corresponding to a bridge circuit in electrical connection with the switch device at the third position.

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