Actuation mechanism with integrated battery

Abstract

The present invention describes a motor-driven actuator device, which includes an actuator motor; a control module; an input for receiving an external power source; and a battery pack. The battery pack is electrically connected to selectively drive the actuator motor and can be electrically connected to the external power source for charging. During charging of the battery pack, the control module is configured to: receive data representing a measured charge level of the battery pack; compare the measured charge level with a predetermined charge level required to complete at least two battery shutdown events under battery power control only, wherein the battery shutdown event involves moving the actuator device to a fail-safe position; and if the measured charge level is equal to or greater than the predetermined charge level, indicate the battery status to other internal components associated with the actuator device. During subsequent operation of the actuator device, the control module is configured to: detect and determine the validity of the external power source, and if it is determined that the external power source is invalid, indicate a battery shutdown event that causes the battery to discharge, so that there will still be enough charge in the battery to complete at least one additional battery shutdown event; and subsequently detect when the external power source becomes valid, and resume the operation of the actuator device under the control of the external power source while recharging the battery pack to at least the predetermined charge level.

Description

Technical Field

[0001] The present invention generally relates to a motor driven actuator device, such as a valve actuator, including an integrated battery. Background Art

[0002] The power supply applied to a motor driven actuating mechanism (such as a valve actuator) is usually provided by an AC mains supply. However, it is known to provide a (usually external) battery backup in such an actuator to provide valve failsafe operation during an AC supply mains failure by utilizing power from the battery source. Thus, in such an actuator, under normal supply conditions, the actuator is operated by the on-site AC power supply. However, if this power supply is interrupted, the actuator automatically switches to receiving power from the battery supply, thereby allowing the valve to be controlled to a (usually externally) pre-configured (failsafe) position.

[0003] However, such batteries usually require a considerable time (such as tens of minutes or hours) to recharge, and during this period the actuator will typically be prevented from operating. Such downtime usually results in significant production and financial losses.

[0004] One solution is to provide a way to quickly recharge the battery after battery powered operation to minimize downtime. However, this comes at the expense of shortened battery life. There are also significant restrictions on the usable temperature range of the battery, limiting the environments in which actuators including the battery can be used.

[0005] It is an aim of embodiments of the present invention to address at least some of these problems. Summary of the invention

[0006] According to a first aspect of the present invention, there is provided a motor driven actuator device comprising:

[0007] - actuator motor;

[0008] - Control module;

[0009] - an input terminal for receiving an external power source; and

[0010] - a battery pack electrically connected to selectively drive the actuator motor and electrically connectable to an external power source for charging;

[0011] Wherein, during charging of the battery pack, the control module is configured as follows:

[0012] - receiving data representing a measured charge level of a battery pack;

[0013] - comparing the measured charge level to a predetermined charge level required to complete at least two battery shutdown events under battery power only control, wherein the battery shutdown event involves moving the actuator device to a fail-safe position; and

[0014] - if the measured charge level is equal to or greater than a predetermined charge level, indicating the battery status to other internal components associated with the actuator device; and

[0015] wherein, during subsequent operation of the actuator device, the control module is configured to:

[0016] - detecting and determining the validity of an external power source, and if the external power source is determined to be invalid, indicating a battery shutdown event that causes the battery to discharge such that sufficient charge remains in the battery to complete at least one additional battery shutdown event; and

[0017] - subsequently detecting when the external power source becomes available and resuming operation of the actuator arrangement under control of the external power source while recharging the battery pack to at least a predetermined charge level.

[0018] An effective external power source is one that is present and equal to or above a predefined power level required to drive the actuator motor, run any peripheral functions of the actuator device, and charge the battery pack (if necessary). An ineffective external power source is one that is absent or below a predefined power level.

[0019] The battery shut down event may involve moving the actuator arrangement to the fail-safe position under battery power control only. The actuator arrangement may be moved to the fail-safe position by driving the actuator motor towards the fail-safe position under battery power control only.

[0020] The predetermined charge level may be sufficient to complete three or four or more battery shutdown events under battery power only control.

[0021] One or more of the actuator motor, control module, and battery pack may be located within the actuator housing.The actuator housing may define one or more enclosures.

[0022] The actuator device may further comprise a driver configured to couple the actuator motor to an external device to be actuated. The driver may be located within the actuator housing. The driver may comprise a shaft and may be configured to couple the actuator device to the external device via the shaft. The shaft may be driven by the actuator motor through a transmission. The actuator motor may be a reversible electric motor. The external device may be a valve. The external device may be a damper.

[0023] In an embodiment, the control module may be configured to prevent operation of the actuator device if the measured charge level is less than a second predetermined charge level required to complete a single battery shutdown event.

[0024] The data representing the measured battery charge level includes voltage and / or coulomb count measurements.

[0025] The control module can also be configured as:

[0026] - receiving data representing the status of an external power source;

[0027] - receiving data representing the charge state and / or status of the battery pack; and

[0028] -When it is determined that the external power source is valid and present and the battery pack needs to be charged, causing the battery pack to be charged from the external power source.

[0029] The actuator arrangement may further comprise at least one temperature sensing arrangement associated with the battery pack.

[0030] The control module may also be configured to, during charging of the battery pack:

[0031] - receiving data representing a measured temperature associated with the battery pack from at least one temperature sensing device;

[0032] - comparing the measured temperature to a first predetermined threshold temperature; and

[0033] - If the measured temperature is greater than a first predetermined threshold temperature, reducing the charging current delivered to the battery pack from the external power source to extend the life of the battery pack.

[0034] If the measured temperature is greater than the first predetermined temperature, the control module is configured to reduce the charging current delivered from the external power source to the battery pack until the measured temperature is equal to or below the first predetermined threshold temperature.

[0035] The battery pack may include a plurality of secondary lithium / nickel metal hydride / nickel cadmium cells arranged and configured for use in an explosion proof environment.

[0036] The actuator device may also include a balanced charging circuit, and circuitry configured to provide overvoltage, overcurrent, and undervoltage protection with respect to the battery cells compared to normal / expected voltage and current levels.

[0037] The actuator device may also include at least one heating device associated with the battery pack. The control module is also configured to:

[0038] - comparing the measured temperature to a second predetermined threshold temperature; and

[0039] - If the measured temperature is less than a second predetermined threshold temperature, switching on at least one heating device until the measured temperature is equal to or higher than the second predetermined threshold temperature.

[0040] The control module may also be configured to delay simultaneous recharging of the battery packs until a temperature of the battery packs is between a first predetermined threshold temperature and a second predetermined threshold temperature.

[0041] The external power source may be a renewable and / or harvested energy source.

[0042] The actuator device may also include an auxiliary system. The auxiliary system may include sensors and / or transducers connected to a remote location via wired or wireless communication for monitoring process conditions associated with the actuator device and reporting data representative of these process conditions. This communication may only be enabled if data needs to be sent to or from the remote location.

[0043] The external power supply may be configured to operate auxiliary systems of the actuator arrangement.

[0044] The external power source may charge the battery pack, and the battery pack may be configured to operate the auxiliary systems and selectively drive the actuator motor.

[0045] The actuator device may further include an integrated control module configured to:

[0046] - controlling the selective driving of the actuator motor according to a defined control process; and

[0047] - Receiving data from a remote location configured to update and / or change a control process.

[0048] The control module can be configured to communicate battery charge level, battery status and / or faults to a user. The battery charge level, battery status and / or faults (collectively referred to herein as "data") can be indicated to the user on a local display (such as via an actuator display). The local display can optionally provide a visual indication of the data. Alternatively or additionally, the data can be transmitted in digital form to a remote location for monitoring, such as by a control system for monitoring. The digital data can be transmitted remotely via a (wired and / or wireless) network. Alternatively or additionally, the data can be transmitted remotely via a discrete signal (such as via a relay). The data can be in the form of a data log.

[0049] The control module may be configurable to operate in a plurality of operating modes, events, and actions in addition to a battery shutdown event. The plurality of operating modes, events, and actions may include a trunk and battery shutdown mode, a trunk and battery actuation mode, and an independent mode; and a trunk and battery shutdown event, a trunk and battery actuation event, and an independent event. The control module may be configured to prevent the actuator device from operating if the control module determines a fault condition in the battery pack and / or determines that the charge level of the battery pack is below a level that would allow a shutdown event.

[0050] The main stem actuation and closing mode is typically referred to as the normal operating mode. The main stem actuation and closing events are typically referred to as the normal operating events.

[0051] In the shutdown mode, the control module may be configured to move the actuator device to a fail-safe position, including moving to any other intermediate position and / or any other limit of movement. A battery shutdown event may include moving the actuator device to the fail-safe position under battery power control only. A main power shutdown event may involve moving the actuator device to the fail-safe position under main power power control only.

[0052] In the actuation mode, the control module may be configured to cause the external power source to operate any auxiliary systems of the actuator device, including causing the battery pack to be charged by the external power source until it receives a move command. In response to the move command, the control module may cause the actuator device to move under power control only from the battery pack in the form of a battery actuation event, thereby discharging the battery pack. When the control module causes the actuator device to move under power control only from the external power source, a trunk actuation event may occur.

[0053] In standalone mode, the actuator device can be powered using an unstable power source such as from a solar panel or wind turbine. Power from these sources can be fed directly into the actuator device and can be used in place of the mains power supply in applications where sufficient mains power is not available. A standalone event can occur when the control module causes the actuator device to move under power control from the standalone power source alone.

[0054] According to a second aspect of the present invention, there is provided a battery management system for a motor-driven actuator device, comprising:

[0055] -Battery management module;

[0056] - actuator motor;

[0057] - an input terminal for receiving an external power source; and

[0058] - a battery pack electrically connected to selectively drive the actuator motor and electrically connectable to an external power source for charging;

[0059] Wherein, during charging of the battery pack, the battery management module is configured as follows:

[0060] - receiving data representing a measured charge level of a battery pack;

[0061] - comparing the measured charge level to a predetermined charge level required to complete at least two battery shutdown events under battery power only control, wherein the battery shutdown event involves moving the actuator device to a fail-safe position; and

[0062] - when the measured charge level is equal to or greater than said predetermined charge level, indicating the battery status to other internal components associated with the actuator device; and

[0063] Wherein, during subsequent operation of the actuator device, the battery management module is configured to:

[0064] - detecting and determining the validity of an external power source, and if the external power source is determined to be invalid, indicating a battery shutdown event that causes the battery to discharge such that sufficient charge remains in the battery to complete at least one additional battery shutdown event; and

[0065] - subsequently detecting when the external power source becomes available and resuming operation of the actuator arrangement under control of the external power source while recharging the battery pack to at least a predetermined charge level.

[0066] An effective external power source is one that is present and equal to or above a predefined power level required to drive the motor, run any peripheral functions of the actuator device, and charge the battery pack (if necessary). An ineffective external power source is one that is absent or below a predefined power level.

[0067] The battery shut down event may involve moving the actuator arrangement to the fail-safe position under battery power control only. The actuator arrangement may be moved to the fail-safe position by driving the actuator motor towards the fail-safe position under battery power control only.

[0068] The predetermined charge level may be sufficient to complete three or four or more battery shutdown events under battery power only control.

[0069] The actuator motor and / or battery pack may be located within the actuator housing.The actuator housing may define one or more housings.

[0070] The actuator device may further comprise a driver configured to couple the actuator motor to an external device to be actuated. The driver may be located within the actuator housing. The driver may comprise a shaft and may be configured to couple the actuator device to the external device via the shaft. The shaft may be driven by the actuator motor through a transmission. The actuator motor may be a reversible electric motor. The external device may be a valve. The external device may be a damper.

[0071] In an embodiment, the battery management module may be configured to prevent operation of the actuator device if the measured charge level is less than a second predetermined charge level required to complete a single battery shutdown event.

[0072] The data representing the measured battery charge level may include voltage and / or coulomb counting measurements.

[0073] The battery management module can also be configured as:

[0074] - receiving data representing the status of an external power source;

[0075] - receiving data representing the charge state and / or status of the battery pack; and

[0076] -When it is determined that the external power source is valid, present and the battery pack needs to be charged, causing the battery pack to be charged from the external power source.

[0077] The actuator arrangement may further comprise at least one temperature sensing arrangement associated with the battery pack.

[0078] The battery management module can also be configured to:

[0079] - receiving data representing a measured temperature associated with the battery pack from at least one temperature sensing device;

[0080] - comparing the measured temperature to a first predetermined threshold temperature; and

[0081] - If the measured temperature is greater than a first predetermined threshold temperature, reducing the charging current delivered to the battery pack from the external power source to extend the life of the battery pack.

[0082] The battery management module may be configurable to operate in a selected one of a plurality of operating modes, events, and actions in addition to a battery shutdown event. The plurality of modes, events, and actions may include a trunk and battery shutdown mode, a trunk and battery actuation mode, and an independent mode; and a trunk and battery shutdown event, a battery actuation event, and an independent event. The battery management module may be configured to prevent the actuator device from operating if the battery management module determines a fault condition in the battery pack and / or determines that the charge level of the battery pack is below a level that would allow a shutdown event.

[0083] The main stem actuation and closing mode is typically referred to as the normal operating mode. The main stem actuation and closing events are typically referred to as the normal operating events.

[0084] The shutdown mode may be selectively configured to move the actuator device to a fail-safe position, including moving to any other intermediate position or any other limit of movement. A battery shutdown event may involve moving the actuator device to the fail-safe position under battery power control only. A main power shutdown event may involve moving the actuator device to the fail-safe position under main power control only.

[0085] In the actuation mode, the battery management module may be configured to cause the external power source to operate any auxiliary systems of the actuator device, including causing the battery pack to be charged by the external power source until it receives a movement command. In response to the movement command, the battery management module may cause the actuator device to move under power control from the battery pack in the form of a battery actuation event, thereby discharging the battery pack. A trunk actuation event may occur when the battery management module causes the actuator device to move under power control only from the external power source.

[0086] In standalone mode, the actuator device can be powered using an unstable power source such as from a solar panel or wind turbine. Power from these sources can be fed directly into the actuator device and can be used in place of the mains power supply in applications where sufficient mains power is not available. Standalone events can occur when the battery management module causes the actuator device to move under power control from the standalone power source alone.

[0087] During charging of the battery pack, the battery management module may be configured to receive data representing the measured life and measured cell impedance of the battery pack, compare these data to a predetermined performance curve, and reduce its charging voltage if the measured cell impedance is greater than the predetermined curve.

[0088] During discharge of the battery pack, the battery management module may be configured to receive data representing a measured temperature associated with the battery pack, compare the measured temperature to a predetermined threshold temperature, and reduce the lower discharge voltage limit if the measured temperature is less than the predetermined threshold temperature.

[0089] During discharge of the battery pack, the battery management module may also be configured to receive data representing a measured temperature associated with the battery pack, compare the measured temperature to a predetermined second threshold temperature, and activate a heating device associated with the battery pack if the measured temperature is less than the predetermined temperature.

[0090] The battery management module may also be configured to delay simultaneous recharging of the battery packs until a temperature of the battery packs is between a first predetermined threshold temperature and a second predetermined threshold temperature.

[0091] The battery management module may be configured to detect and determine the validity of an external power source and:

[0092] (i) if the external power source is valid and a valid shutdown command has been received, causing a shutdown event powered by the external power source to be implemented; and

[0093] (ii) if the external power source is invalid or is determined to be invalid, and / or a valid shutdown command has been received and / or a trunk shutdown event is in progress, switching from an externally powered shutdown event to a battery shutdown event that discharges the battery such that there is still sufficient charge in the battery to complete at least one additional battery shutdown event.

[0094] The battery management module can be configured to enable the motor-driven actuator device to operate normally, wherein the battery pack is in an idle or charging state unless it is determined that the external power supply is invalid and / or a valid shutdown command is received, thereby correspondingly implementing an external power supply shutdown event or a battery shutdown event.

[0095] The battery management module can also be configured as:

[0096] - Checking the status of the battery pack with respect to any one or more of the following parameters: battery status, degradation rate and / or service / maintenance requirements;

[0097] - generating data representing one or more parameters; and

[0098] -Report data:

[0099] o reporting the data on a local display (such as via an actuator display screen), which optionally provides a visual indication of the data; and / or

[0100] o Reporting data to a remote location for monitoring (such as by a control system for monitoring) via a network (wired and / or wireless) and / or via discrete signals (such as via relays).

[0101] The data may be in the form of a data log. BRIEF DESCRIPTION OF THE DRAWINGS

[0102] Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

[0103] Figure 1 is a schematic diagram showing a valve actuator;

[0104] Figure 2 is a schematic block diagram showing the configuration of an actuator, a battery pack, and an actuator control module of a valve actuator; and

[0105] Figure 3 is a schematic flow chart showing a battery management method. DETAILED DESCRIPTION

[0106] Embodiments of the present invention are particularly relevant to valve and damper actuators in, for example, the power generation industry, oil and gas flow control, marine applications, water facilities, and process industries. Such valve actuators typically have an output shaft that is driven by a reversible electric motor through a gear drive (such as a worm gear drive) and that can move in either direction to open or close a valve that is connected to the output shaft through a valve stem.

[0107] Figure 1 A valve actuator is shown comprising a main housing 1 and a terminal housing 2. Both housings are airtight to maintain watertight integrity and protect internal components. The main housing houses a control module 3 (such as a position control device and load sensor) and a drive train 4. A display and local controller 5 may be housed in a cover on the main housing.

[0108] A battery pack 6 is mounted within the main housing and electrically connected to the actuator. The actuator also includes a battery control module 7 for managing the battery pack and operating the actuation mechanism. The battery pack includes a plurality of cells, such as secondary lithium cells, which are typically wired in series with diode protection between the cells.

[0109] The precise number of cells used and the wiring configuration utilized will depend, at least to some extent, on the capacity and power to be achieved, and also on the space available to accommodate the final battery pack. Secondary lithium cells may be used in valve actuators of the type described above, as they are suitable for use in explosion proof (EP) devices. However, other suitable cell types, such as nickel metal hydride or nickel cadmium, may be used instead.

[0110] In battery packs of the above type, intelligent balancing charging circuits are provided to protect the battery cells from overcharging, overdischarging or overdischarging (also known as overvoltage, overcurrent and undervoltage protection, respectively). Secondary battery cells have a limited optimal temperature range, and additional circuits and heat dissipation holes in the cell housing are provided to prevent overheating.

[0111] Figure 2 The configuration of the actuator 10, control module 12 and battery pack 14 is shown. The control module 12 may have the above-mentioned balanced charging and overvoltage, overcurrent and undervoltage protection functionality, although this is not required and these functions may alternatively be provided in a separate module / PCB. In the following description, the main features of the battery management function of the actuator control module will be described. Although the main features mentioned above are all described as part of the same actuator control module, the actuator control module functionality may alternatively be provided in a module form, where one or more of the functions are provided in a separate device / PCB, and / or provided away from other functions.

[0112] Embodiments of the valve actuator, and in particular the battery pack used therein, have three modes of operation, referred to herein as: Off, Battery Actuated, and Standalone; and five operating actions: Normal, Mains Off, Battery Off, Battery Actuated, and Standalone; and several final action types, each of which is supported by integrating a battery pack of the type described above within the valve actuator and coupling thereto via a battery management function provided as part of the actuator control module. In embodiments of the invention, all of the above modes may be implemented using the same hardware, using different corresponding (switchable) configurations. Additional hardware may be used for the Standalone mode of operation, typically to convert solar energy into electrical energy.

[0113] The following describes the battery management system in shutdown mode with normal, trunk shutdown and battery shutdown operating events and command and power loss actions. However, many aspects are relevant to all operating modes, events and actions.

[0114] The control module, and associated battery management process flow, provides active voltage and current management (with respect to the battery pack), diagnostics (located within the valve actuator), status feedback functionality, low temperature management (using heaters to assist performance and keep the battery cells within their optimal operating temperature range), and high temperature management to extend the operating life of the battery cells. In this exemplary embodiment, the valve actuator (and associated battery pack and control module) will be suitable for use in EP environments and non-EP environments within the temperature range of -50°C to 70°C.

[0115] The battery pack is queried by the battery management (or actuator control) module to determine the battery temperature, battery capacity, battery voltage, and the level of charge remaining within the battery pack / cell. The present invention is not limited in the manner in which these parameters are determined. The primary utility and advantage of the control module according to this embodiment is that it uses these sensed / calculated parameters to manage the battery pack, make decisions, and take the best action for the user and / or the battery pack based on these parameters. It can also report battery pack faults based on these parameters in an art where this level of battery management was not previously possible.

[0116] A major benefit is that in the past, it has not been practical to use a battery pack in a valve or damper actuator while complying with EP specifications, except in specific circumstances. Although secondary lithium and similar battery cell technologies can be used in EP (and other) hazardous environment applications, their optimal operating temperature range is limited and they require careful management (especially when charging and discharging). Therefore, embodiments of the present invention attempt to address these issues. Overtemperature protection is provided electronically and using heat dissipation holes in the cell housing. The battery pack additionally uses a heater when the ambient temperature drops below a predefined (and configurable) point set by the actuator control module. Therefore, these measures can be used to keep the battery cells at the optimal operating temperature for charging and discharging, and can be selectively turned on and off by the actuator control module when necessary. At high temperatures, the actuator control module can decide when to charge the battery pack and the rate at which the battery pack is charged, thereby helping to extend the operating temperature range and extend the life of the battery pack.

[0117] Furthermore, during the life of the valve actuator, the battery pack will inevitably degrade. The available battery capacity will particularly degrade at temperatures below 0°C, and at the end of the battery life. The actuator control module may have a built-in map of such degradation, and in conjunction with battery capacity sensing, the actuator control module may vary the charge level and voltage to maximize the life and performance of the battery at different stages of its life. Additionally, there may be a built-in map of battery capacity versus temperature that may be used to allow the control module to compensate for different temperature conditions.

[0118] An actuator control module (with battery management functionality) may be communicatively coupled to the integrated battery and configured to monitor and control battery operation according to an operating mode and a plurality of associated respective parameters, as will be described in greater detail below.

[0119] Figure 3 A flow chart showing a battery management (or control) module and a battery management method.

[0120] The battery management flow chart starts from step 100 , where when the module is powered on, or after the battery pack is in an idle state, a subsequent charging process flow may be triggered.

[0121] Once the process flow begins, the actuator control module checks the status of the battery pack (at step 102) for the following parameters:

[0122] Charge level;

[0123] ·temperature;

[0124] ·Fault:

[0125] ο Undervoltage;

[0126] o overvoltage; and

[0127] o Overtemperature; and

[0128] Unit status and / or service / maintenance requirements.

[0129] The actuator control module selects the event and action operating mode based on the current state of the mains power level and whether the battery pack is safe to use, the actuator is safe to operate, and the battery pack needs to be charged. Therefore, at step 104, the actuator control module checks whether the mains power connected to the valve actuator is valid (i.e., sufficient to drive the motor, operate the peripheral functions of the valve actuator, and charge the battery pack (if necessary)).

[0130] If (or when) it is determined that the available mains power is valid, the battery is safe to use and is fully charged, and the actuator is safe to operate, the valve actuator operates as a conventional motor-driven valve actuator (defined herein as a normal operating event), which is powered by the available mains power and the battery pack is in an idle condition (and is configured to provide the desired valve fail-safe operation in the event of a corresponding command, power loss and / or actuator failure).

[0131] If it is determined that the mains power present is invalid (i.e., not present or below a defined level), and / or a valid failsafe command is received, but the battery is safe to use, the actuators are safe to operate, and there is sufficient charge in the battery pack (i.e., sufficient charge to complete at least two battery shutdown events), the actuator control module will cause a battery shutdown event to occur. In this mode, the actuator moves to a predetermined position or limit under battery power control, either immediately or after a configurable wait time.

[0132] If the mains power present is determined to be valid (i.e. present and above a predefined level) and a valid shutdown command is received, the actuator control module will cause a mains shutdown event to occur. In this mode, the actuator moves to a predetermined position or limit under mains power control, either immediately or after a preconfigured wait time, with the battery as a backup (this may result in an automatic battery shutdown event if the mains power is deemed invalid).

[0133] During a battery shutdown event, the valve actuator will be controlled by power received from the battery pack:

[0134] Move from any position to the full open limit, thereby stopping at the load (i.e. torque and / or thrust) limit or position;

[0135] · Move from any position to the fully closed limit, thereby stopping at the load limit or position; and / or,

[0136] · Move from any position to any other intermediate position.

[0137] When valid mains power is restored, the actuator will re-enter normal operation (this is normal whether battery actuated or independent), provided that (or when) the battery pack is sufficiently charged to allow at least one further battery shutdown event.

[0138] If it is determined at step 104 that mains power is available (and it is determined at step 102 that the battery is safe to use but needs charging), the actuator control module will begin charging the battery pack at step 106. In the battery charging process flow loop, the actuator control module again checks mains power at step 108 and again checks if all battery safety checks pass at step 110. If mains power remains normal and the battery safety checks all pass, the battery pack charging process flow proceeds to step 112.

[0139] At step 112, the actuator control module receives data from the temperature sensor representing the temperature of the battery cells and their surroundings. The actuator control module then compares the sensed temperature to a predetermined high threshold. If the battery pack temperature is determined to be too high compared to the predetermined high threshold, then at step 114, the actuator control module reduces the charging current to the battery pack. This portion of the process is iterative and may be repeated in steps until it is determined that the battery pack temperature is below the high threshold and / or within a predetermined range.

[0140] Next, the actuator control module compares the current battery pack temperature to a predetermined primary low threshold value at step 116. If the battery pack temperature is determined to be too low compared to the predetermined primary low threshold value, the actuator control module is configured to activate the battery pack heater at step 118. Again, this portion of the process flow may be iterative and repeated until it is determined that the battery pack temperature is within a temperature range defined between the high threshold value and the primary low threshold value.

[0141] According to an embodiment of the present invention, the charging scheme can be adjusted according to the degree of aging / deterioration of the battery pack. Therefore, in step 119a, the battery life log is periodically updated. In step 119b, the control module compares the life log with a predetermined reference curve. If in step 119c, it is determined that the battery pack is close to the beginning of its life, it is charged at a predetermined low voltage (step 119d), and if it is determined that it is not close to the beginning of its life, it is charged at a predetermined high voltage (step 119e).

[0142] During charging of the battery pack, at step 121, the control module receives data representing the measured charge level of the battery pack from the voltmeter and / or ammeter, such as voltage measurements and / or coulomb counting measurements. The control module then compares these measurements to a first predetermined charge threshold. The first charge threshold is the charge level required to perform at least two battery shutdown events (e.g., move the actuator to a fail-safe position at least twice under battery power control only). That is, the battery pack is capable of performing at least two shutdown events under battery power control only. In the case of an actuator moving a valve, the fail-safe position can be a normally open or normally closed position of the valve.

[0143] If the measured charge level is equal to or greater than the first predetermined charge threshold, the control module sets a system flag (referred to as a double buffer flag) that indicates the battery status to the rest of the system (step 127).

[0144] If the control module detects a loss of mains power, a first shutdown event typically occurs. The system then switches from mains actuation to battery powered actuation to execute a battery shutdown event. A battery shutdown event may involve moving the actuator to a fail-safe position under battery power control only. When the double buffering flag is present, after the first shutdown event, the control module detects when mains power is restored and safe for use, and then restarts operation under mains power control. At this point, there is still enough charge in the battery to complete at least one additional battery shutdown event (if necessary) (e.g., additional mains power interruption).

[0145] When operation is resumed under mains power control, the battery may also begin to recharge simultaneously using mains power. The system does not need to wait until the battery is fully recharged before resuming normal actuator operation. Typically, the battery may take tens of minutes or hours to recharge, during which time actuator operation is typically prevented. Having the ability to perform at least two shutdown events under battery power control alone means that after the first shutdown event, the battery pack does not need to wait to recharge before being ready to perform another shutdown operation. This helps reduce operational downtime, which in turn helps minimize any production and financial losses that typically occur during downtime.

[0146] In addition, since there is enough charge in the battery to complete at least a second shutdown event when operation is resumed under main power control, the simultaneous recharging of the battery can be performed at a much slower / relaxed rate. As previously mentioned, it is possible to quickly recharge the battery after a shutdown event, but this is at the expense of shortened battery life and a limited battery usable temperature range. In addition, if the battery pack is outside the optimal temperature range, the simultaneous recharging of the battery pack can be delayed until the battery pack is within the optimal temperature range. The slower charging rate, and also delaying charging until the battery pack is within the optimal temperature range, helps to maintain and extend battery life and allows operation in more extreme temperature ranges. In this way, the actuator and battery pack of the present invention can be used in a wider range of environments.

[0147] If, at step 121, it is determined that there is not enough battery charge to complete at least two shutdown events, then any previous double buffer flag set by the control module is cleared, step 129. This tells the system that there is only enough charge for a single shutdown event and that if a battery shutdown event occurs, there will not be enough charge remaining in the battery to perform any additional shutdown events.

[0148] The control module also compares the measured charge level to a second predetermined charge threshold. The second charge threshold is the charge level required to complete a single battery shutdown event using only battery power control. If mains power is available and determined to be safe for use, and the measured charge level is less than the second predetermined charge level, such that the charge level of the battery pack is below a level that would allow even a single battery shutdown event, the control module can be configured to determine whether to: resume normal actuator operation under mains power control, or prevent actuator operation until the battery has been recharged to at least the first predetermined level by mains power.

[0149] The above charging and temperature detection / management process is repeated and continued until a charge end signal is detected from the charging circuit at step 120. At this point, the actuator control module is configured to stop charging the battery pack at step 122 and check again whether the mains power is normal at step 123. The process flow also checks at step 124 whether the battery pack has self-discharged, if so, the process flow returns to step 106, and the actuator control module starts charging the battery pack.

[0150] So, in summary, once the status of the battery pack has been checked at step 102, if the battery pack is not faulty (i.e., the battery pack is safe to use), the actuator control module will decide the next step based on the requirements determined by the current operating mode. If the battery pack requires charging, the actuator control module will turn on the constant current / constant voltage source to charge the battery pack as needed. The voltage charge level is determined and controlled by the age of the battery cells, and the current level is determined by the temperature and the charging power set by the user.

[0151] Any fault detected in the battery pack can be reported to the user via the actuator display or the status relay of the actuator itself or a network system (wired and / or wireless) connected to the actuator at step 125. In addition, the actuator control module can decide whether to continue operation based on the above-mentioned sensed parameters and preset user configuration.

[0152] During and after battery charging, the actuator will operate normally without reference to the battery pack unless:

[0153] a) The battery reports a serious fault (in which case the actuator control module exits the process flow and generates an error signal to be reported / displayed); or,

[0154] b) Active mains power is removed; or an active shutdown command is received and mains power is removed; or an active shutdown command is received, mains power is present, and the actuator is configured to move primarily on battery power (in which case the actuator control module will enter the shutdown operating mode described above).

[0155] During charging, the battery management function of the actuator control module will monitor whether the battery is safe to use and whether the actuator is safe to operate. If any of these checks fail, an error condition will be flagged. The actuator control module also monitors whether active mains power is lost and / or whether an active shutdown command is received, and if any of these conditions are met, the actuator control module enters the shutdown mode described above.

[0156] Finally, when the battery reaches the predefined current limit at the predefined voltage level, charging will end, thereby generating a charge end signal. The predefined voltage level may vary depending on the age of the battery and the ambient temperature. At this point, the battery management function checks the stable battery voltage, and if the voltage is within a predetermined range, the battery pack will enter the idle condition described above until it is determined that it needs to be charged. If this criterion is not met, the battery management function returns to step 106 and resumes the charging process.

[0157] Charging ends as before when the battery pack reaches a predefined voltage limit, which can vary depending on the age of the battery. As mentioned earlier, at this point the battery management function checks for stable battery voltage.

[0158] If this meets the predetermined criteria, the battery pack will enter the idle state described above until it is determined that the battery pack needs to be charged. If the criteria are not met, the battery management function returns to step 106 and resumes the charging process.

[0159] Whenever the battery pack is enabled at step 126, whether in a battery shutdown event or a battery actuation event, the battery management function enters a discharge process flow. In this process flow, the actuator control module again monitors the battery pack temperature, but in this case only compensates for low temperatures, i.e., below the primary low threshold (e.g., 0°C) and the secondary low threshold (e.g., -30°C). At step 132, the battery management function checks to determine if the temperature is below the primary low threshold. If so, it turns the heater on at step 134. Next, it determines the cell impedance across the battery pack. If so, it isolates the battery pack and stops discharging at step 130. If not, the process flow returns to step 126 and the battery pack can continue to be used.

[0160] Of course, another significant advantage of the battery pack and associated active battery management process flow is that the battery pack can operate in a selected one of many operating modes, rather than in a single passive shutdown or fail-safe mode provided in the above-described conventional valve actuators with integrated batteries.

[0161] In shutdown mode, the actuator operates as a normal mains powered electric actuator until mains power drops below a predetermined threshold and / or a valid shutdown command is received. As described above, this may be with or without a configurable time delay between the event and the shutdown action. The actuator will then make a decision based on the mains power level and / or the nature of the shutdown command to initiate a mains shutdown event or a battery shutdown event, which has been described previously.

[0162] In battery actuation mode, mains power (whether from the grid or from a renewable energy source) is used to run the actuator's peripheral systems and charge the battery pack. When the valve is to be moved, the battery pack is discharged to operate the actuator motor and then recharged between movements. This will also be described as a battery actuation event. If so configured, the actuator can initiate an additional battery shutdown event if the mains power drops below a predetermined threshold and / or a valid shutdown command is received. This can be with or without a configurable time delay between the event and the shutdown action (as described above), and with or without the presence of mains power.

[0163] As described below, the independent mode is similar to the battery actuation mode in many respects, wherein additional hardware is provided to allow a direct, optimized supply from a renewable energy source and to allow the connection of additional peripherals, such as sensors. The power typically derived from the solar panel is used to run the peripheral systems of the actuator and to charge the battery pack. This is referred to as an independent event. When the valve is to be moved, the battery pack is discharged to operate the actuator motor and then recharged between moves. This will also be described as battery actuation. If so configured, the actuator can also initiate a battery shutdown event if the main power drops below a predetermined threshold and / or a valid shutdown command is received and / or the battery is discharged to a predetermined level. As described above, this can be with or without a configurable time delay between the event and the shutdown action.

[0164] These additional operating modes will now be described in more detail.

[0165] In battery actuation mode, the actuator control module is able to actuate the valve from a power source with less power than that required to operate the electromechanical actuator. Mains power (whether from the grid or a renewable energy source) is used to operate peripheral systems and charge the battery pack. When it is necessary to move the valve, the battery pack is discharged in step 126 to operate the actuator (described herein as a battery actuation event). In this operating mode, a so-called deep sleep mode (described below) can be utilized to maximize the amount of charge entering the battery pack, wherein an automatic wake-up signal is generated when the actuator motor is to be operated. If it is determined in step 128 that the battery pack voltage is lower than a predefined cut-off voltage, the actuator control module isolates the battery in step 130 and marks an error.

[0166] To enable a battery actuation event, in charge mode, the battery management function will charge the battery pack using the available mains power, and the battery pack is used to move the actuator in all cases. In this case, when the actuator wants to run, the actuator control module checks:

[0167] a) Is there enough battery charge?

[0168] b) Whether the actuator has exited deep sleep mode;

[0169] c) whether the battery is safe to use; and

[0170] d) Whether the actuator can operate safely.

[0171] If all these conditions are met, the actuator will run from any set position to any other set position. Valid inputs will be either digital signals, analog levels or network commands.

[0172] If there is an error with the battery or actuator, the error will be reported and the actuator will decide if it is serious enough to prevent operation. If the battery is undercharged, this will prevent operation until there is enough charge.

[0173] To charge the battery pack, and when the battery pack is not being used to move the actuator, the process flow returns to steps 102 and 104. If there is sufficient mains power, the battery can be safely used, the actuator can be safely operated, and the battery requires charging, the actuator control module will begin charging the battery pack at step 106. During battery charging, if so configured, the actuator enters a power save (or deep sleep) mode and the battery pack is not used until a valid movement command is received. The battery pack will charge unless the battery reports a serious fault (in which case an error state is flagged and the system will not operate), active mains power is removed (in which case the system enters the battery shutdown event described above), or a valid movement command is received (in which case the actuator will operate from any set position to any other set position, as described above). These parameters are monitored throughout the charging process.

[0174] The battery actuated mode described above can be used in mains powered systems, and / or in systems fed by renewable energy sources, such as by solar, wind and / or hydro. Therefore, a so-called standalone operating mode is also envisaged, and this will now be described in more detail. The standalone operating mode is very similar to the battery actuated operating mode, and the battery actuated events and battery shut-off events are identical in operation. The main differences are the power supply and the ability to make process decisions from local sensors powered by the actuators and / or to wirelessly transmit information back to the control center so that movement commands can be sent wirelessly to the actuators in return.

[0175] In the standalone operating mode, the valve actuator can be powered using an unstable power source from, for example, a solar panel or wind turbine. Power from these sources can be fed directly into the actuator and can be used in place of the mains power supply in applications where sufficient mains power is not available. The actuator control module manages the energy supply and stores the energy in the battery pack. The power to the actuator runs the peripheral systems and charges the battery when sufficient power is present, and the battery pack then powers the actuator motor and other systems when commanded and / or when insufficient power is present. As mentioned above, the battery management function can put the battery into a so-called deep sleep mode in order to maximize the amount of charge entering the battery, being awakened only when needed. As with all other modes, the status can be reported visually, wired or wirelessly, and in this case the device is able to connect directly to third-party sensors and process the information according to user set points.

[0176] The power source can be solar radiation through a third party solar panel. The actuator will be able to control and optimize the output of the solar panel or other power source through power point tracking and deliver the resulting power supply to the actuator battery bank. The main advantage of this system is that the solar panel array does not need to be able to directly drive the actuator motor, so the battery will be used as a storage battery to drive the motor and bridge the sunlight gap caused by darkness or shadows. The method of operation should be consistent with the battery actuation mode.

[0177] In terms of functionality, valid signals will be received wirelessly in addition to the conventional hardwired commands and network. The actuator can reply with status information via the same wireless communication. This allows for a completely standalone solution.

[0178] The final aspect is the attachment of external sensors (such as pressure sensors). This allows the actuator to make internal process decisions and change its own set point with or without reference to the central control set point. If the process exceeds the set parameters, the actuator can send a warning message to the controller through wired or wireless communication.

[0179] In the event of a complete power loss, such as due to a failure of a solar panel, the actuator will move from any position to a preset set safe position and report an alarm either wired or wirelessly in the event of a battery shutdown as described above.

[0180] From the foregoing description, those skilled in the art will appreciate that modifications and variations may be made to the embodiments described without departing from the scope of the present invention as defined by the appended claims.

Claims

1. A motor-driven actuator device, comprising: - actuator motor; - Control module; - an input terminal for receiving an external power source; and - a battery pack electrically connected to selectively drive the actuator motor and electrically connectable to the external power source so as to be charged by the external power source; Wherein, when the battery pack is charged by the external power source, the control module is configured to: - receiving data representing a measured charge level of said battery pack; - comparing the measured charge level to a predetermined charge level required to complete at least two battery shutdown events, wherein a battery shutdown event involves moving the actuator device to a preconfigured fail-safe position under battery power control only; and - if the measured charge level is equal to or greater than the predetermined charge level, indicating the battery status to other internal components associated with the actuator device; and wherein, during subsequent operation of the actuator device, the control module is configured to: - detecting and determining the validity of the external power source, and if it is determined that the external power source is invalid, indicating a battery shutdown event that causes the battery to discharge so that sufficient charge remains in the battery to complete at least one additional battery shutdown event; and - subsequently detecting when said external power source becomes available and resuming operation of the actuator arrangement under control of said external power source while simultaneously recharging said battery pack to at least said predetermined charge level.

2. The actuator device of claim 1, wherein the control module is configured to prevent the actuator device from operating if the measured charge level is less than a second predetermined charge level required to complete a single battery shutdown event under battery power only control.

3. An actuator arrangement according to claim 1, wherein the data representative of the measured charge level comprises voltage and / or coulomb counting measurements.

4. The actuator device according to claim 1, wherein the control module is configured to: - receiving data representing the status of said external power source; - receiving data representing the state of charge of said battery pack; and - when it is determined that the external power source is valid and present and the battery pack needs to be charged, causing the battery pack to be charged from the external power source.

5. The actuator device of claim 1, further comprising at least one temperature sensing device associated with the battery pack.

6. The actuator device of claim 5, wherein the control module is further configured to: - receiving data representing a measured temperature associated with the battery pack from the at least one temperature sensing device; - comparing the measured temperature to a first predetermined threshold temperature; and - if the measured temperature is greater than the first predetermined threshold temperature, reducing the charging current delivered from the external power source to the battery pack to extend the life of the battery pack.

7. The actuator device of claim 6, wherein if the measured temperature is greater than the first predetermined threshold temperature, the control module is configured to reduce the charging current delivered from the external power source to the battery pack until the measured temperature is equal to or lower than the first predetermined threshold temperature.

8. The actuator device of claim 6, further comprising at least one heating device associated with the battery pack; and wherein the control module is further configured to, during charging of the battery pack: - comparing the measured temperature to a second predetermined threshold temperature; and - If said measured temperature is less than said second predetermined threshold temperature, switching on said at least one heating device until said measured temperature is equal to or higher than said second predetermined threshold temperature.

9. The actuator device according to claim 1, further comprising a control module, wherein the control module is configured to: - controlling the selective driving of the actuator motor according to a defined control process; and - receiving data configured to update the control process from a remote location.

10. An actuator device according to claim 1, wherein the control module is configured to communicate a battery pack charge level, a battery pack status and / or a fault to a user; and wherein the battery pack charge level, the battery pack status and / or the fault are indicated to the user on a local display forming part of the actuator device, and / or are digitally transmitted to a remote location via a network for monitoring.

11. An actuator device according to claim 1, wherein the control module can be configured to operate for multiple operating modes, other events and actions in addition to operating for the battery shutdown event; and wherein the multiple operating modes, other events and actions include a battery actuation mode, an independent mode, a trunk shutdown event and a battery actuation event.

12. The actuator device of claim 11, wherein the control module is configured to prevent the actuator device from operating if the control module determines a fault condition in the battery pack.

13. An actuator device according to claim 11, wherein in the battery actuation mode, the control module is configured to operate any auxiliary system of the actuator device through the external power supply, including causing the battery pack to be charged by the external power supply until the actuator device receives a movement command; and wherein in response to the movement command, the control module causes the actuator device to move under the control of power from the battery pack in response to the battery actuation event, thereby discharging the battery pack.

14. The actuator device according to any one of claims 1 to 13, further comprising an actuator housing, wherein one or more of the actuator motor, the control module and the battery pack are located within the actuator housing.

15. A battery management system for a motor-driven actuator device, comprising: -Battery management module; - actuator motor; - an input terminal for receiving an external power source; as well as - a battery pack electrically connected to selectively drive the actuator motor and electrically connectable to the external power source so as to be charged by the external power source; Wherein, when the battery pack is charged by the external power source, the battery management module is configured to: - receiving data representing a measured charge level of said battery pack; - comparing the measured charge level to a predetermined charge level required to complete at least two battery shutdown events, wherein a battery shutdown event involves moving the actuator device to a preconfigured fail-safe position under battery power control only; and - if the measured charge level is equal to or greater than the predetermined charge level, indicating the battery status to other internal components associated with the actuator device; and Wherein, during subsequent operation of the actuator device, the battery management module is configured to: - detecting and determining the validity of the external power source, and if it is determined that the external power source is invalid, indicating a battery shutdown event that causes the battery to discharge so that sufficient charge remains in the battery to complete at least one additional battery shutdown event; and - subsequently detecting when said external power source becomes available and resuming operation of the actuator arrangement under control of said external power source while simultaneously recharging said battery pack to at least said predetermined charge level.

16. The battery management system of claim 15, wherein the battery management module is configured to prevent operation of the actuator device if the measured charge level is less than a second predetermined charge level required to complete a single battery shutdown event under battery power only control.

17. The battery management system of claim 15, wherein the data representative of the measured battery charge level comprises voltage and / or coulomb count measurements.

18. The battery management system according to claim 15, wherein the battery management module is further configured to: - receiving data representing the status of said external power source; - receiving data representing the state of charge of said battery pack; and - when it is determined that the external power source is valid, present and the battery pack needs to be charged, causing the battery pack to be charged from the external power source.

19. The battery management system of claim 15, wherein the actuator device further comprises at least one temperature sensing device associated with the battery pack.

20. The battery management system according to claim 19, wherein the battery management module is further configured to: - receiving data representing a measured temperature associated with the battery pack from the at least one temperature sensing device; - comparing the measured temperature to a first predetermined threshold temperature; and - if the measured temperature is greater than the first predetermined threshold temperature, reducing the charging current delivered from the external power source to the battery pack to extend the life of the battery pack.

21. A battery management system according to claim 15, wherein the battery management module can be configured to operate in one of multiple operating modes, other events and actions in addition to operating in response to a battery shutdown event; and wherein the multiple operating modes, other events and actions include a battery actuation mode, an independent mode, a trunk shutdown event and a battery actuation event.

22. A battery management system according to claim 15, wherein during charging of the battery pack, the battery management module is configured to receive data representing the measured life and measured cell impedance of the battery pack, compare the data representing the measured life and measured cell impedance of the battery pack with a predetermined threshold, and if the measured cell impedance is greater than the predetermined threshold, reduce the charging voltage of the battery pack.

23. A battery management system according to claim 15, wherein during discharge of the battery pack, the battery management module is configured to receive data representing a measured temperature associated with the battery pack, compare the measured temperature with a first predetermined threshold temperature, and reduce a lower limit of the discharge voltage if the measured temperature is less than the first predetermined threshold temperature.

24. The battery management system according to claim 15, wherein: During discharge of the battery pack, the battery management module is configured to receive data representing a measured temperature associated with the battery pack, compare the measured temperature with a second predetermined threshold temperature, and activate a heating device associated with the battery pack if the measured temperature is less than the second predetermined threshold temperature.

25. The battery management system of claim 15, wherein the battery management module is configured to detect and determine the validity of the external power source, and: (i) if the external power source is valid and a valid shutdown command has been received, causing a shutdown event of the external power source to be implemented; and (ii) if the external power source is invalid or is determined to be invalid, and / or a valid shutdown command has been received and / or a trunk shutdown event is in progress, switching from a shutdown event powered by the external power source to a battery shutdown event that discharges the battery such that there is still sufficient charge in the battery to complete at least one additional battery shutdown event.

26. A battery management system according to claim 15, wherein the battery management module is configured to enable the motor-driven actuator device to operate normally, wherein unless it is determined that the external power supply is invalid and / or a valid shutdown command is received, the battery pack is in an idle or charging state, so that an external power supply shutdown event or a battery shutdown event is implemented accordingly.

27. The battery management system of any one of claims 15 to 26, wherein the actuator motor and / or the battery pack are located within an actuator housing.

28. A battery management module for a motor-driven actuator device according to any one of claims 1 to 14, the battery management module comprising the control module.

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