WO2014033467A2

WO2014033467A2 - Mobile electrical power module

Info

Publication number: WO2014033467A2
Application number: PCT/GB2013/052281
Authority: WO
Inventors: Danny Jones
Original assignee: Off Grid Energy Ltd.
Priority date: 2012-08-31
Filing date: 2013-08-30
Publication date: 2014-03-06
Also published as: GB201215564D0; WO2014033467A9; GB2506015A; WO2014033467A3; GB201315467D0

Abstract

An electrical power module (11), configured as a default operational reserve, for self-contained, stand-alone operation, or in conjunction with selectively harnessed external resources, including engine driven generators, mains supply, wind or water turbines and solar PV panel arrays, features an internal re-chargeable DC battery power resource (12), an AC and/or DC power input or charging circuit, an AC and/or DC power output or delivery circuit, an inverter and/or bi-directional power converter 14 in or between the input and output circuits, an intervention or coupling intermediary between inverter-charger and a battery, with a load interface, an interface for coupling to an external AC or DC power supply, a control circuit for selectively applying external power for internal battery (re-)charge, whilst allowing output draw down of an internal DC charge; a diverse mix of power resources can be recognised and automatically to different load demands, with the supply and demand balance variable with circumstances; prioritised and phased load shedding is implemented if demand load exceeds power available from combined external and internal sources; with loads selectively re-instated in priority ranking when power becomes available.

Description

Mobile Electrical Power Module

This invention relates to electrical power sources or supplies, in particular but not exclusively self-contained power supplies, such as for stand-alone use on-site where mains grid power is unavailable or requires stand-by back-up. A durable self-contained power resource would be desirable, as would a facility to harness and switch between diverse power sources, whether internal or external, as and when available.

Batteries and inverters have been used variously for back-up and standby power supplies. A battery can provide direct DC at or around the battery voltage or AC at a different, usually higher, voltage through an inverter. In 'reverse' mode, an inverter can be configured to serve as a battery charger by converting AC to DC at or just above the battery voltage.

Reliance upon batteries alone has not been widely adopted for variable ad hoc demands, as batteries need to be matched to loads and to a compatible recharge facility, such as a generator or mains supply if available. Batteries can be drained up to close capacity at a variable rate, but have their own issues on security, reliability and longevity of supply. A facility to work on occasion for a period without a generator charge is advantageous. Even a mains grid as a primary or recharge resource is subject to reliability and fluctuation within bounds. It is not without inherent losses, such as in transmission.

Inverters with integrated transfer switching are known. Thus, in a particular configuration, 24V 180AH Lithium-ion batters are harnessed with 2 or 3 48V 8kVA inverter-chargers. Hitherto battery and inverter combinations have not provided the flexibility for harness in conjunction with external generator or mains supply. A flexible interface between supply and recharge facilities would be desirable. A generator might be fitted with a solo start battery of sufficient capacity to drive a diesel engine starter motor, and local ancillaries such as task lighting or small electrical power tools, but not a battery intended as part of an external supply or supplement.

Small-scale, hand-portable or trolley-mounted rechargeable battery units are known for remote vehicle starting battery charging, but are generally inadequate for heavy discharge required for obstinate starting conditions and rapidly depleted and vulnerable to short service life and long term battery damage through excessive sporadic demand and are difficult to keep adequately charged for unpredictable duty cycle. Such miniature chargers or boosters may also be fitted with a small inverter to provide mains voltage, but at lower current and power draw. The starter with a sudden very high current demand burst and continuous mains demand are somewhat at odds, and problematic for choice of battery type and charge capacity; and also vulnerable to mis-use.

A battery might be regarded as passive in comparison with an active generator, but batteries have their own issues. Batteries require periodic charging for storage between re-charging and draw-down, generators require continuous availability and supply of fuel to run at all. Over capacity or under-utilisation is wasteful of resource capabilities. Conversely, under- provision means failure to meet demand. Battery orientation is important to guard against inadvertent leakage of electrolyte. Ventilation is necessary. Operationally, for unsealed construction regular periodic checks on electrolyte level are required. This can be conducted by visual inspection or by remote sensors to trigger a warning indication. Service life is impaired by under or over-charging - bulk charge, adsorption charge, float charge, equalisation, frequency. A battery is commonly constructed as a homogeneous body of self- contained cells for collective overall electrical voltage effect; but in some aspects of the invention can be sub-divided or compartmentalised flexibly into isolated individual sub- compartments or sub-assemblies. Similarly, with multiple battery grouping. Thus for a battery based prime power resource special attention must be paid to battery characteristics and behaviour.

A facility to scale up or down to match the vagaries of unpredictable fluctuating demand would also be desirable. In some variants of the present invention modules are configured for mutual intercoupling and face interfit or stacking. Aside from plug and cable interconnection, a complementary profile interfit, such as a jigsaw piece interfit might be adopted.

A common provision for off-site, off-grid power is to rely primarily upon a diesel engine driven generator, but this is noisy, expensive and emits pollutant exhaust gases, so is not environmentally friendly, having poor 'green' credentials. Local regulatory constraints, such as with a public order or health and safety agenda, may also constrain out-of-hours engine running. Moreover, an engine fuel tank limits run time. Plant or facilities hire for on-site use typically caters for generators, themselves reliant upon a fuel supply such as through an attendant tank or mobile bowser.

A generator operation can also be inflexible in requiring a minimum driving engine speed and a continuous even speed for optimum economy, but which operating mode may not correspond with generator load demand. A control complexity of responsiveness and stability arises if electrical load demand fluctuation is to dictate engine speed and/or torque. Wild excursions of running speed and draw down power are not tenable.

Special smoothing or damping provision to counter output voltage and/or current fluctuation may also be required and to isolate sensitive or vulnerable loads from transients or spikes, which are potentially damaging to downstream electronics and to suppress electromagnetic radiation which a dynamic generator is prone to produce.

Switching engines and generators repeatedly on and off with demand fluctuation is inefficient for a combustion engine without special design, engenders mechanical wear and tear, requires high starter currents and is noisy electrically with sudden generator run-up and run- down mode transition. A relatively quiet, subliminal background, if not wholly 'silent', low emissions power source alternative, with the necessary demand load capacity and longevity is desirable.

One challenge is prediction of the level and variability of fluctuation pattern of local demand. Thus, capacity over-provision is wasteful and expensive and under-provision risks sudden and potentially hazardous loss of supply. Load-splitting, balancing, allocation or

apportionment according to criticality of need and safety consideration is also desirable, such as with emergency or backup lighting preserved as a last resort, but ancillary decorative or floodlighting sacrificed if overall demand is excessive in relation to power reserves.

Generally, users or consumers are not informed about or interested in the nuances of power supply characteristics so their power demands can be inconsiderate to the power supply facility available. Training or education of consumers of site power on the reasonable expectations and limitations of their temporary power source, with help or prompts upon load saving or phased consumption to preface any automated intervention would be desirable but not feasible for a diverse changing user base. Thus some automated intervention might be contemplated. An expert learning or behavioural mode from past operational experience could be situation specific to 'tune' supply provision to forecast demand and adjust the set-up to meet that.

Selection and configuration of battery power requires a careful balance of considerations. Battery discharge characteristics may differ from those for charging. Different battery types have their own charge and draw-down or discharge characteristics, which must be compatible with or matched to a load for optimum battery performance, service life and continuity of provision. (Modest) heat might be generated in either battery or inverter, to counter which internal or external cooling provision might be made. Periodic full charge cycle may be necessary to preserve battery life and delivery or drawn-down performance.

A power module of the invention can supervise and regulate the draw-down of power from the generator, whose output might be split selectively between and an active load and a longer term battery (trickle or boost) recharge.

There are a disparate variety of battery types, with different charge and discharge characteristics, suited to different end uses or applications. A primary battery categorisation is non-rechargeable vs chargeable. Lead acid re-chargeable batteries are common as a robust, heavy, low-cost construction, but can suffer progressive internal irreversible chemical degradation, such as plate sulphate coating in prolonged non-use. If AC draw-down power is required from a DC battery power source, an electronic DC-AC converter such as a switch mode inverter is required in circuit. Certain battery types, such as lithium ion are well-suited to that.

A battery body may thus contribute some chassis stiffness and rigidity. A cellular construction can contribute to stiffness and rigidity. Similarly with a module housing structure.

The Applicant has found that immediate environment, such as bespoke physical configuration and housing of a power source can also a contributory role in the practicalities of operation. Another consideration is remote battery charging or supplement with wind or water turbine power driven generators or by photovoltaic cells in solar PV panel arrays. Statement of Invention

A self-contained site electrical power (re-)source or supply comprising

one or more electrical charge reservoir or storage modules, such as batteries,

mutually harnessed or intercoupled in selectively re-configurable clusters, groups or banks, and co-operatively disposed with respective power conversion units,

for charge from a power grid and discharge into a connected load.

The power (re-)source is conveniently configured as a compact self-contained packaged unit or module, such as a rhomboid or cuboid, polyhedral format, or pyramid in a common housing, for micro power generation in a pod. Principal internal content elements include batteries and solid state semiconductor (switch mode) power converters or inverters, in particular inverter / chargers for generating AC output power for delivery to a load from a DC battery output. A group of 'n' batteries associated or matched with a group of 'p' inverters. A plurality of battery sub-groups is wired with selective variable or adjustable association or matching with a sub-group of inverters. This allows batteries or inverters to be selectively disabled or uncoupled, such as for maintenance, servicing, repair, replacement or substitution. Individual batteries can then be switched into standby mode. Thyristors, such as silicon controlled rectifiers (SCR), can be used to effect inverter switching ; such as of an input transformer winding. A single or polyphase inverter / (bi-modal) charger configuration may be adopted according to the AC mode required.

As a safety over-ride provision to an normal fuse or relay trip, an emergency disable or shut- off switch facility is operable to shut down and isolate the module from both the load and any external mains or generator power source. This supercedes any regular control settings. The action can be reversed to re-enable the module in a single action.

A rechargeable battery bank is harnessed through a solid state bi-directional converter with control and instrumentation circuitry. The (module) can serve as either an alternative to a (diesel) fuelled ic engine generator or run in tandem.

Operationally, a power module of the invention is a deployable power supply intended either as an alternative to a diesel (or other fuelled) generating set or in tandem with a separate generating set. The module comprises of a rechargeable battery bank and a solid state bi- directional converter combined with control and instrumentation circuitry. It serves if a mains supply is not available.

Working on it's own, the module operates in Inverter mode to provide silent, emission free AC electricity to a load, with a capacity up to the rated output and with a duration relative to the limits of the energy stored within the battery. The specification table will define the capacities of each specific model. The module will continue to deliver power until the battery capacity has been depleted.

When used in tandem with a discrete generating set, a power module of the invention working in battery charger mode will use the electricity supply from the generator to re-charge the battery bank, whilst simultaneously supplying the power from the generator directly to the load. When the generator is switched off or disconnected (and no mains supply available), the invention will automatically revert back to Inverter mode to supply the load from the battery reserve.

The module can be fitted with a feature to provide automatic start/stop control of an otherwise external generator by means of a two wire, volt free signal. The start and stop command can be based on a range of programmable parameters. The module can also be connected to a grid mains power supply, where available, for the purposes of re- charging the battery.

Advanced function options include a so-called 'Input Assist', where the capacity of the connected power supply can be 'set' into the machine thus enabling the unit to keep the draw from the supply within that capacity. This function has two primary benefits:

1 . to enable automatic adjustment of the power used to charge the battery to compensate for increases in energy demand by the load ; and

2. to enable the power module to 'top-up' the input power supply in the event that the load demands more power than the supply can deliver.

When connected, the auto start signal can be used to tell a connected generator to start or stop depending on, for example, the state of charge of the battery or the level of power demanded by the load. These parameters can be adjusted by re-programming the machine using a lap-top computer connected to the machine 's data port.

Various optional features are available including a remote monitoring module that provides web-based access to real-time performance data and for re-programming, an option to connect a Solar PV array to charge the battery and/or support the load and also a road-tow option to enable the unit to be towed behind a vehicle. Other options can be added including custom specified features.

A solar PV cell array in a flat panel format can be mounted on the housing for battery charge replenishment;deployment of such a solar PV array can be by out-fold from a compact mutually overlaid folded up segmented panel format for transport and storage; an extendible, say telescopic, pylon may also be used to carry a solar PV array; a fluted pylon cross-section may be used for greater stiffness; an end wall of a housing is one convenient location for a folded solar PV panel array, cluster or group; overlaid or stacked butterfly wing or iris segment solar panels allow a compact folded form with a greater and different deployed form ;

deployment into alternative forms may be contrived ; along with different partial or full deployment;

A module or unit can effectively be used as an effectively uninterruptible, or fail-safe, power supply in conjunction with a mains grid, by responding to grid failures with a substitute power derived through an inverter from a battery source, preferably rechargeable, n that way a continual alternating cycle of discharge drawn down and periodic re-charge for replenishment can be employed. A circuit arrangement for selective detachable intercouple of battery and inverter may feature a bus-bar for convenience of isolator switch and fuse connection or mounting. A read-out or other visual and/or audio indication of drawn-down and projected resource life is conveniently mounted on the housing.

A remote data link for monitoring and control, with allied data logging for record and analysis can be provided through an interface; a cell phone link could be used to carry such data; an in-built sensing, monitoring and diagnostic (SMD) module capable of looking 'backward' internally at the supply resource and/or 'forward' externally at the demand load would be desirable. Circuit sensing may included local sampling and scanning for errors, such as continuity or bridging and to pin down location of circuit breaks.

A map of anticipated or projected circuit conditions can be compared with a plot of actual conditions for a given load level and character and a tolerance or out-of-range allowance applied before initiating any warning or corrective action ; the map could include levels against time or waveforms. Corrective, ameliorative or restorative action could be partial off-load or 'cap' on demand, before wholesale cut-off ; with time allowance for a load behaviour to settle down. The effects of correction could be periodically revisited, with a modest time allowance for relatively minor, non-damaging or fatal fault conditions or transient excursions to remain in case self-correcting, before pro-active intervention. Nevertheless, these could all be accumulated stored for learning about load behaviour and ongoing circuit development or reconfiguration, such as to contrive automated remedial response action. Users could be encouraged to specify their demand expectations in advance and then given a retrospective plot of actual demand to help them adjust or regulate their usage; this would enable more realistic expectations to be set in advance and met with adequate capacity. A signal generator could be incorporated to send test signals into the supply and/or load sides, with an analyser connected to receive derivative circuit conditions; a test signal could be a continuous or pulsed waveform to trigger certain harmonic subsidiary waveforms when applied to circuit elements.

With a plurality of batteries connected to a common or shared bus or distribution bar or rail, mutual electrical isolation could be provided to inhibit mutual discharge or electrical shorting between batteries. Such isolation could be adapted to suit similar or diverse battery voltages, charge capacities or types. Similarly, with a plurality of inverters also connected to a common or shared bus or distribution bar or rail, mutual electrical isolation could be provided to inhibit mutual electrical coupling between inverters; such isolation could be adapted to suit similar or diverse inverter operating voltages, currents, capacities or types. Mutual coupling only between certain designated individual batteries and inverters could also be prescribed. That said, with certain safeguards, interchangeable cross-coupling between batteries and inverters might be admitted, such to allow battery or inverter change without supply service capacity reduction or interruption. Fixed format or adjustable setting fuses, trip switches or relays might be fitted in critical circuit paths.

Intercoupling in series and/or parallel combination or otherwise ganging together batteries or battery cells for increased capacity and/or voltage can be through a master bus bar or connector rail and associated intervening coupling switches, which may be electromechanical or solid state, such as silicon controlled rectifiers SCR's or other gates. Battery terminals may require positive mechanical 'screw-locking' clamps on threaded terminal stems for cable connection between batteries or onward, for security and to meet wiring regulatory dictates. Fuse links or bridges may be fitted in feed or delivery lines for greater security to obviate circuit or component overheat or damage; fuse character, such as 'slow-blow' (overheat controlled) 'overload threshold tolerant', or 'short-circuit intolerant' are adapted to suit circuit conditions and demand. Fuses may be changed or swapped around to meet transient periodic condition change. An intelligent adaptable or programmable fuse could be adopted. A friction detent or snap-action plug-in / pull-out cartridge format fuse link lends itself to that. A multi (twin)-pole isolator switch can be fitted on the supply side from the battery for master (dis-)connection in a single action. A rotary switch format would allow that. Interconnection of battery cells is more permanent, such as fixed straps, ties, tabs or bars. A DC interface could admit linkage to mains power grid or an optional solar PV panel array. Primary wiring for a DC output side from a battery could also serve for battery charge; that is two-way use or routing of certain feed lines. Provision for individual battery cell condition check could be through hard-wired or wander probes.

A circuit could be configured with a DC side and an AC side or section, with certain mutual intercouple or common interface; a DC side and an AC side could be separated by an isolator interface. An AC side could feature a bi-directional converter coupled to one side of a DC link and sensor module. The circuit is also configured with a resource side, with an internal battery reserve, an input side to receive charging power from a diversity of external resources, such as an active diesel engine driven generator or a passive solar PV array, and an output power delivery side. Output could be selectively switched between DC and AC power; AC (output) power is derived from a DC (input) source by or through an inverter; conversely, AC power input can be converted to DC power for internal battery (re)charge; a dual mode converter or inverter/charger is convenient for this.

A power module can be considered in primary sub-divisions or sections, in relation to a physical housing vis:

INTERNAL

1 .

a resource side or section generally characterised by DC power provision;

2A.

an output power or power delivery side or section configured or adaptable for either DC or AC power provision;

2B.

an output power diversion side or section configured or adaptable to interface with and harness diverse external and/or internal sources; with a control monitoring and

communications section including instrumentation, control / distribution gear and a communications module;

EXTERNAL

3.

a recharge, replenishment, backup or boost side or section can be an external i.e. engine- driven generator, an external mains, solar PV array, another coupled power module harnessed for that purpose, or some combination, permutation or multiple of such facilities.

Internal configuration can reflect battery type or mix; this to optimise battery usage and life, given a battery is an expensive and vulnerable resource, with precious material ingredient.

Use of the power module has a pronounced effect upon its operation, serviceability and longevity. Misuse, however arising, regardless of whether inadvertent or through ignorance, can damage the module and batteries; such damage can be permanent and irreparable. Abuse may also pose a fire or explosion, so personnel health and safety risk. Provision to mitigate or inhibit this would be desirable.

As regards battery condition and (re-) conditioning, a power module can be configured to address battery factors, including:

a modest but prolonged trickle (input) charge, to boost and preserve battery condition;

for certain battery types, such as nickel cadmium, regular battery use or 'exercise' can be beneficial ; for other battery types excessive or additional cyclic duty could reduce life, so moderate use is key;

a modest self-recovery or resuscitation effect can arise, according to battery type; a controlled charge-discharge regime can prolong battery service life;

· particularly when the underlying cyclic profile, or depth of discharge, can be

managed ;

certain battery types, such as NiCad, albeit now virtually obsolete, have a 'memory' or history related behaviour, which can be used to advantage, but which if mis-used can undermine life; albeit may be reversible with full charge-discharge cycles;

A battery charge level or effectively an internal resource fuel gauge can be contrived ; onboard battery analyser tools can be harnessed to test, exercise and restore batteries. Battery performance deterioration can arise with battery age from date of manufacture through internal chemical changes; such changes can be affected by temperature, with more rapid degradation or capacity loss at higher temperature; extreme low temperatures such as freezing conditions should be avoided. A digital history of battery performance and usage can be contrived by recording all inputs and outputs; charging voltage can be critical for battery life. A charging regime of charge current limitation, while monitoring battery voltage and temperature is desirable. An optimum charge state is employed for battery storage. Any or all such features can be the subject of a monitoring and control program. A facility to arbitrate between different internal battery types according to type or condition, which tends to deteriorate with age, would help best use of internal resources, without necessarily having to change batteries. That means not only selection, but regulated draw-down in the light of condition. Synchronisation or harmonisation of AC phases or cycles between diverse power sources can also be implemented ; AC frequency can also be adjusted ; multiple independent AC streams of diverse frequency and/or relative phase can be accommodated.

Other feature or characteristic options include ...

sensing nature of load characteristic e.g. resistive / reactive / impedance ;

sensing load pattern over time e.g. stable / fluctuating-variable / volatile;

adapting internal power supply output to suit / match load - response time ;

· synchronising internal supply with another ENERGY CELL;

synchronising internal supply with external grid ;

preserving over-load / over-voltage / over-current protection ;

predicting / anticipating demand - learning from past experience;

harnessing other power resources + safe (de-)coupling ;

· internal configuration, passive battery pack / active generator;

selective enabling of internal features

- e.g. battery reserve drain to trigger threshold for generator charge ;

intelligent fusing / trip - overload safety margin for lighting power;

plug in / remote system diagnostics;

· remote sensing, monitoring + control ;

synchronisation / harmonisation - with demand + replenishment;

variable frequency AC output capability - frequency increase for greater power transfer;

automated switch on + off / enabling-disabling of batteries with demand ;

· hold batteries in reserve - for selective deployment;

(all) batteries harnessed in bank together for burst mode demand ;

output filter to even out / dampen surges / surge suppression ;

charge mode regulation + control to protect / optimise battery life;

admit mixed capacity batteries (type + ageing) - with 'pick 'n mix' demand draw-down ; · allow standby reserve modules - switch in / out according to circumstances - to

maintain continuity of off-grid supply;

link / interaction with mains grid - allow joint draw-down and/or charging from grid ; link / interaction with generator - automated sensing + matching of generator capacity;

· safety / battery protection overload and/or short circuit fusing - avoid unnecessary sudden disabling of load ;

regulated superimposed load shedding in response to prolonged excessive demand ; operation

AC modes: AC input (mains or generator charging) + AC output (draw-down through external load);

DC modes: DC feed to thyristors to convert by switch-mode to AC output;

allow option of direct DC output draw-down, say for charging external batteries; discrete independent fusing of DC + AC sides;

display computed supply life projections for different demands;

allow user selection / arbitration between draw-down + supply life in reaction to 14; automated on-board foam sprinkler fire protection;

a variable frequency AC output could be contrived, with say a high frequency mode for higher power delivery or transfer without excessive current;

Overall, the facility to accumulate, store, conserve and allow controlled, say phased or staged, release of energy serves as, equates to, or might be loosely regarded as an energy flywheel, with an electrical equivalent a certain static bulk / mass and/or dynamic inertia and momentum. Energy drawn-down or extraction could be regarded as flywheel motion braking; the severity, timing and duration of demand (braking) determines the longevity of supply (momentum). A battery charge can decay through internal chemical action, even with no demand. Periodic use allows some internal recovery if not re-charge. Excessive demand risks being expressed as wasteful heat, with material damage, rather than useful work.

Unregulated, sporadic or undisciplined ongoing or continual call-down or drain of energy, more rapidly depletes the stored energy reserve; whereas matched or compatible demand and storage helps preserve continuity of supply, with deferral of energy top-up; demand regulation can be critical to longevity of supply. When a reserve external power charging facility is or becomes available, such as when a power module is re-located from site to site, a periodic charge-discharge cycle optimised for particular battery characteristics 'on board' may be implemented to take best advantage of battery capabilities and prolong battery service life. A (re-)charge or release from service prompt or recommendation program can be generated from a battery condition monitor, with guidance upon the charge rate and duration. A low reserve or poor condition battery can be taken out of service for 'calm' quiescent self- recovery, active recharge or replacement in favour of fresh battery reserve.

In order to cope with extreme highs or peaks of demand, a pro-active hunt for extra capacity may be initiated, in a quasi local mini-grid function, so a supplementary pick-up 'call' or 'polling' may be placed on other sources or reserves; or indeed one or more other such power modules; so multiple resources can be harnessed in unison together, say in series and/or parallel. A master controller may be used to harness multiple power modules; this may be implemented through a control unit in any one or more power modules, any one of which may be given temporary master authority, individually or collectively with the control units of other power modules harnessed co-operatively in a distributed command mode, with different subsidiary and/or back-up roles; under-utilised reserves may themselves take the initiative in alerting the network to, putting forward, or 'pushing' their 'service capability offer'. Such an offer may override any polling initiative, so onward polling is adjusted accordingly.

Power modules may be configured, or selectively (re-)configurable differently, such as through hard-wired circuitry, programmable firmware or software for collectively operation; thus modules might be adapted to deliver different voltage, current, frequency or phase to different parts of a demand load, from allotted internal sub-circuits. Multiple subsidiary power circuits can be enabled for independent or co-operative running; a mix'n match conjunction or juxtaposition of power modules with diverse capabilities or configurations allows flexibility in meeting demand changes. Arbitration between otherwise competing load demands and differently configured power modules could be contrived. Power modules need not be located immediately adjacent one another for that purpose, but can be individually connected to a common load by various independent routings from different locations. Similarly, a mix of loads could be grouped for servicing by a mix of power modules, in a local power

(sub-)network, matrix or mini-grid. Local load connections and power modules would serve as network nodes. An example would be a work site spread over a large area, with diverse loads deployable at different and variable locations over the site, and which might change as a site develops and expands; a mine or tunnelling construction site would be a case in point.

Quiet running and non-pollutant power modules would have a particular advantage in confined or underground sites. Similarly, with elevated sites on hills or mountain sides, such as power line or other utility servicing and construction. The bulk, weight and mobility of power modules is a particular consideration for site working. A rugged, weather-resistant power module construction and housing, with shielded electrical connections would allow all- weather operation, whilst preserving ventilation, such as for internal battery heat dissipation; with selective local removable shielding covers for internal access.

Miniaturised modules would lend themselves to lighter duties and also to cluster combination with other modules, such as in a common carrier frame, yoke, harness shelter or sling; to this end a snug interfitting outer profile could be of particular value; a compact format allows mutual weather shielding.

Although a rectangular format is convenient for fabrication, a sloping sided such as trapezoidal section format could provide self-drainage. Similarly, with curved, not necessarily rectilinear forms. In either case, a saddle format could allow modules to be stacked one upon another.

Electrical coupling of multiple modules in parallel can provide higher power output, single phase or multi-phase capacity and/or supply longevity; an internal system bus facilitates interconnection and control, such as automated switch-on to supplement or replace a failed mains supply.

Embodiments

There now follows a description of some particular embodiments of a power module of the invention, by way of example only, with reference to the accompanying diagrammatic and schematic drawings, in which ;

Figure 1 shows the AC side of a power module circuit for AC power output delivery, at a prescribed voltage up to a certain current capacity, to a demand load (not shown);

Figure 2 shows the DC side of a power module circuit for an internal battery resource;

Figure 3 shows an overview of a power module, such as of Figures 1 and 2, in the context of external charging sources such as a generator, mains grid or a solar PV panel array;

Figures 4A, 4B, 4C and 4D show a series of elevations of a mounting chassis for principal elements of the module of Figures 1 -3, with battery rack, inverter bay, cable routing, plug and socket connectors and display panels. An rigid internal chassis mounting tray and partition wall upstand imparts stiffness and rigidity.

Figure 5 shows views of a demountable outer housing, with connector access and display panels; a demountable side wall, along with an ventilated 'safari' style roof with local elevated panel is depicted, with the option of further, say longitudinal housing split for ease of access to internal elements; in a variant layout connections and controls could be grouped in associated clusters accessible through apertures in one end wall. A housing can feature a demountable 'U' or 'C section shell lid with end flanges for end panel mounting incorporating local ventilation louvres and one or more access apertures for connections and

instrumentation of internal componentry.

Figures 6A, 6B, 6C, 6D show views of a collapse-(over)folding solar PV panel array, configured for roof mounting upon the housing of Figure 5, with bespoke folding support frame and damped pivots; a base panel is canted with a swivel bearing to optimise orientation to the prevailing sunlight.

Single AC phase is reflected in the example, but multiple phase variants could be configured for greater power handling capacity; such as by repeated individual circuit provision for each isolated phase with optional output combination.

A power module 11 can be configured to absorb, digest and store any available local power for future use. It is flexible upon the nature of that power, such as whether AC or DC or whatever voltage, and can adapt automatically to such availability. All or only some of the available power can be absorbed, with a charge rate adaptable to what other demands are being placed upon the available power. Ultimately, internal battery capacity limits the rate of charge which can be accommodated and just how much total power can be stored. The module can decide the rate of discharge in response to load demand and the total power released. In that regard a conservation agenda can be set, so discharge rate is balance against longevity of availability.

The overall power module 11 configuration allows a flexible and adaptable marriage, interplay or interpolation of diverse external power resources, internal battery 12 power resource and external loads. Primary external power resources include an i.e. engine driven generator 19 or a local mains supply. Secondary external power resources include a wind and/or water turbine driven generator and solar PV panel arrays.

A minimum power module 11 'default' condition or operational mode is reliance upon a self- contained internal DC battery source 12. This can be drawn directly as DC voltage or, more likely, converted to AC voltage and adjusted in voltage, most likely elevated, to serve an external load demand for AC; such as a load which might normally be serviced from a external AC mains supply. Upon failure of a local AC mains, or in remote sites where mains service is or suddenly becomes unavailable, loads requiring mains AC voltage would have to be off-loaded or remain unused; absent substitute provision such as by the power module 11 .

As and when one or more other external power resources becomes available, one or more can be taken up and used on its own account or combined with other external resources and/or the default internal battery resource 12. The power module 11 can blend such diverse power resources and adapt continually and promptly to changing circumstances of supply and demand. The power module 11 can thus arbitrate between competing load demands and available power resources. It can moderate, orchestrate or intervene by temporarily calling upon dormant resources.

External resources might be either AC or DC power. Thus a mains supply would be AC, as would likely be power from a wind or water turbine. An external engine or turbine powered generator would produce AC in the first instance, which could be used directly, or with voltage adjustment such as step up, or converted to DC in the generator output circuitry. However, the power module 11 has its own such AC to DC power conversion facility. An external solar powered PV array would generate DC, usably directly or converted to AC. AC/DC or DC/AC conversions have attendant losses, so are best minimised, not repeated or reversed;

Again, the balancing of supply and demand load by the power module 11 takes account of whether AC and/or DC is available or required. Either or both AC or DC can be provided by the power module 11 through switching circuit elements, to suit diversity of load demand.

The internal DC battery resource reduces or obviates dependence upon external mains or generator (re-)charging, at least for a useful independent operating time, and reduces the environmentally unfriendly use of generators, whose own fuel resources is limited. Fuel tank top-up replenishment in remote sites is costly, so desirably minimised or avoided. Rather, once charged-up, a portable power module 11 can be trailered periodically to a remote site and left to operate as a low noise, pollution-free, on-call resource.

Referring to the drawings, schematic wiring cable or harness routing between principal internal units is depicted in a distributed regular rectilinear geometric map format for ease of illustration; the actual physical layout, disposition and mutual separation of elements may differ in practice from that shown.

In Figure 1 an AC side or section of a power module 11 features a master bus bar, conductor rail, or terminal connector block 20, for ease of wiring interconnection between principal circuit elements; the terminal block 20 is shown as a single straight length bar, but other configurations and segmentations can be adopted. The connector block 20 helps preserve wiring order discipline, consistency and conformity to standard. To this end, colour coding can be applied to individual terminal block connectors.

The connector block 20 serves as a distributed electrical interface board for power (or rate of change of energy) flow, transfer between an AC (or DC) output side, an AC or DC input side and external AC or DC charge feeds; that is power can flow in either or both of two ways and at the same time. Thus power can be drawn selectively from one or more available resources. Availability may change, but that can be accommodated; power is drawn from selected available resources only just as and when needed to meet load demand, which again may change but which is met with an appropriate blend of resources. A minimum internal resource is the DC battery 12; beyond that, external resources are called upon, such as an external engine powered AC generator, a local AC mains supply (not shown), a wind and/or water turbine powered AC generator (not shown), a solar PV panel array, shown in Figure 6.

At one (upper right-hand) supply side, an output socket group or cluster 18 through a cable spur with switched (fuse link) isolator 13. The sockets 18 can provide independent or coordinated output feeds of similar or different rated voltage, current or wattage capacity. The sockets 18 are supplied by one or more dual or reversible mode inverter / charger units 14 connected at the opposite side of the block 20.

Sensing, monitoring or command signals can also be overlaid upon power supplied through sockets 18; either outgoing to a load (not shown) or incoming from a load, such as to monitor load condition or demand. Such signals are differentiated in frequency and character and isolated from the power transfer.

The output sockets 18 each supply single phase AC power when the power module 11 is so configured; but might also be used to deliver DC power with appropriate circuit

(re-)configuration; or indeed a mixture of AC and DC power delivery might be contrived. DC output would be useful for re-charging external batteries, or for running other DC devices, such as battery driven radios, or other audio-visual equipment without external conversion losses; that said some AC / DC conversion losses might be tolerated internally; thus voltage change is more readily effected in AC mode before any conversion to DC.

Typically, power storage is DC through batteries, absent feasible economic AC storage such as through capacitor banks; that said, the power module 11 might be adapted to provide a sudden impulse, surge or boost power, such as though capacitive discharge, to trigger or 'kick-start' an load activity. Certain inductive loads such as motor windings may require special output. AC storage would require continual balance of generation and load balance to avoid frequency changes.

On its AC side, depicted in Figure 1 , each inverter / charger unit 14 has an AC input terminal AC1 in /87 and a pair of AC output terminals AC1 out / 89, AC2 out / 91 , only one of which is shown connected. Terminal block 20 allows DC power from the DC battery pack 12 though a DC circuit shown in Figure 2 to be fed to each inverter / charger unit 14. On its DC side, depicted in Figure 2, each inverter / charger 14 has a pair of differentiated polarity DC input / output terminals 93 along with a polarity sensing terminal 95.

Mechanically, the power module 11 sits on a chassis 45 within a housing of Figures 4 and 5; power outlet sockets 18 are conveniently accessible externally of the module 11. An AC inlet socket ACIN01 / 19, depicted to the lower left hand side of terminal block 20, is connected as dual feed lines plus an earth line to the lower side of the terminal block 20 and thence on the other side of the block 20 to a two line input isolator switch 1101 / 13 and thence back across the block 20 to the AC1 in (input) side of both inverter / chargers 14. Socket 19 can receive AC power from an external mains supply (not shown) or from an engine driven generator 17 shown in the overview circuit layout of Figure 3.

The inverter / charger units 14 are grouped in gangs or clusters, configured independently or co-operatively harnessed to feed the AC side through the terminal block 20 and fed, again through the terminal block 20, to a DC battery resource side detailed in Figure 2. One of two AC output terminals of each inverter / charger 14 is connected through the terminal block 20 through twin bank two line isolator switches 16, with earth lines in common, to an output socket array or bank 18.

In one 'delivery' or draw-down output mode, the inverter / chargers 14 can delivery AC power from a DC source, such as internal battery pack 12. In another (re-)charge mode the inverter / chargers 14 can convert AC power from an external power source into a DC charge for the internal battery pack 12. This to replenish what is effectively the only stand-alone self- contained power source, allowing independent operation until the charge is depleted if not exhausted, or until another re-charge source is accessible.

On the AC side, a battery monitor BMV01 / 31 is connected through the block 20 to a fly lead AS and a tapping in one of the inverter / chargers 14. Adjacent other inverter / charger side tappings have an interconnection 96. A multi-function battery status and condition monitor 29 with a digital display is connected to a tapping in one of the inverter / chargers INV01 / 14.

On the DC side, battery monitor BMV01 / 31 is connected to a shunt 38 in a feed between one battery pole 33 and the corresponding polarity DC terminal 93 of the inverter / charger INV01 / 14. An opposite battery 12 pole is connected to common terminal 35 in turn coupled through a single pole master switch BMS01 / 32 to split fuse links 37, 39 in lines to the corresponding polarity terminals 93 of the inverter/chargers 14. A cross-coupling fuse link 36 is connected between terminal pole 35 and shunt 38. A nominal DC voltage of 48 volts may be employed across the grouped battery packs 12. This as a unitary multiple of individual cell output voltages for the particular battery type. A higher DC voltage allows reduced current to service a load. The terminal block or connector bus 20 allows complex, traceable wiring, without cable entanglement, with clear colour-coded visual presentation and separation to facilitate wiring checks. It also facilitates wiring change for re-rigging or test. According to service duty requirements, inverter / chargers 14 may be introduced, disconnected or changed over. Each inverter / charger 14 has an AC input terminal 87 and one or more AC output terminals AC1 , AC2 / 89, 91 , not all of which need be used at any one time; connected through the terminal block 20 to the output socket cluster 18. Inverters 14 can be interlinked through secondary links 96. An earth stud 63 is also provided to allow a common earthing between elements, an a ground spike.

An auto start socket 61 is connected to spur line AS for command of either an external AC generator 17 or an external AC mains supply, as and when available and connected, to initiate charging of battery 12 by DC power conversion of generator 17 AC output by inverter / converters 14 automatically or by manual command set to operate in that AC to DC power conversion mode. If an external AC source is available, it can be applied wholly or partially to service an external AC load demand and / or to directed through the inverter / chargers 14 to re-charge internal batteries 12. Alternatively, an AC load can be met partially by external resources or partially by conversion of DC battery power. A balance of external supply and load can thus be achieved ; the overall system can be directed, such as by an operating and command program, to respond to circumstances and (re-)adjust that balance. One objective could be to minimise generator 17 usage with attendant noise and exhaust pollution and consumption of limited generator fuel tank reserves.

Intelligent load sensing and recognition and similarly with available power sources are pivotal to demand and resource matching. Load demands can be resistive and /or reactive, that is capacitative and/or inductive; but what might be designated real power transfer is resistive. In Figure 2, a DC side couples a battery 12 to inverter / chargers 14 through isolated positive and negative circuit lines, for battery output in discharge mode or input in charge mode. On the positive side, battery feed lines DC01 , DC02, DC03 from certain battery cell sub-groups are taken to a shared positive terminal TP1 / 35 and from there through a single feed DC07 to the input side of a battery master switch BMS01 / 32. Split positive output feeds DC09, DC10 from the master switch 32 are taken to respective through fuse links FS0 1 / 39, FS02 / 37 to the positive DC (input) sides of a pair of inverter / chargers INV01 , INV02 / 14. On the negative side, battery feed lines DC04, DC05, DC06 are taken to a shared negative terminal TP2 / 33 from which a single feed DC08 is taken to a shunt ST01 / 38 from which it is split through lines DC11 , DC12 to the respective negative sides of the inverter / chargers INV01 , INV02 / 14. A tapping line DD01 / 81 is taken from the shunt ST01 38 to a battery monitor BMV01 / 31. A sensing terminal 82 of one inverter / charger INV01 / 14 is is also coupled back through a feed line TS01 / 85 to a common conjoined mid-pole battery cell 86. In practice the feeds would be colour coded by polarity, albeit not visible in the drawing.

Figure 3 shows a wider overview of a power module 11 in conjunction with external resources. The power module 11 bounded by a rectangular border with external factors beyond that; an i.e. engine driven generator 17 is coupled to one side; a passive solar PV panel array 15 is coupled to another side; a battery group or cluster 12 of close-coupled interconnected cells is housed internally; along with one or more inverter modules / chargers 14.

Figures 4A (end elevation), 4B (side elevation) and 4C (plan view), variously show the mechanical elements of a power module 11 physical structure. In this case a folded, stamped or pressed sheet metal fabrication is employed, but elements, particularly covers, also lend themselves to plastics mouldings to reduce weight and provide electrical insulation. A base chassis 45 supports all internal components beneath an external demountable weather- resistant ventilated housing or over-cover 50 shown in Figure 5. The chassis 45 carries a main upright or upstand (battery) bulkhead 43 which separates a battery compartment, with a battery tray 41 , from an inverter / charger compartment, with an inverter / charger bulkhead 44 secured to the main bulkhead 43. An instrument mounting and connection plate 47 is also secured to the main bulkhead 43. Plate plane intersection contributes to overall torsional stiffness, resisting distortion in lifting and handling.

The sectioned or segmented, compartmented format with intermediate sub-division partition walls 48 securely locates contents and inhibits movement during transit, particularly for mobile trailer variants. Tie down fasteners, straps and clamp bars or plates (not shown) may also be fitted. The arrangement provides physical and electrical separation, allowing for 'flash-over' protection and electromagnetic screening. A lightening conductor might couple to the chassis with a grounding point to an earth spike. Transit mountings such as for road or rail track wheels or flotation tanks could also be fitted.

The chassis 45 is sufficiently rigid, stiff and robust, such as of deep-sided turned depending edge section, to allow for other roles than merely contents support. Thus chassis 45 could feature wheeled axle and drawbar mounting (not shown) for use as a towable road trailer behind a vehicle; similarly, other trailers might be towed in tandem. Side outriggers could be fitted as cantilevered brackets to support outboard ancillary equipment such as telescopic masts for aerials, satellite dishes or folding booms to carry solar PV panel arrays. Lifting eyes could be fitted for crane lift suspension and/or slots for tines of fork lift trucks, telescopic boom handlers or the like; upright stanchions could be fitted for rack stacking of multiple modules 11 as a grouped power installation.

In a particular chassis construction, two straps (or braces) are welded to the base and then a pre-formed cross beam member of substantial gauge steel bolts to these two braces. This serves primarily as a load bearing member capable to taking the weight of the laden module without distortion. A fixing point for a lifting eye is positioned at the horizontal C of G. As a secondary function, the same brace and beam arrangement serves as a fixing point for two side panels also ensuring rigidity of the completed / fitted carcass.

Whilst a rectangular planform chassis 45 is shown, other formats, such as polygonal or segmented, could also be employed to suit particular contents and operational requirements. A jigsaw fashion interfit or internest of multiple individual chassis profiles could serve compact stacking and/or packing with mutual stabilisation bracing and support. A floating pontoon mounted variant might also service for marine use, as a support services tender; or a power module might be lifted from dockside cranes deck booms and secured to a deck platform or lowered into a cargo hold. Military, utility or civilian aide agency or emergency rescue variants might be extra rugged, even to allow parachute drop from heavy lift aviation. Provision for sub-division into knock-down, quick-assembly kit form might also be adopted to reduce the gross payload. Heavier or bulkier contents such as batteries might be installed on cantilevered sliding, quick-demount frames, with 'plug an play' connection.

Figure 5 shows a housing 50 installed upon base chassis 45; a removable side access panel 51 allows reach from outside into internal parts for routine maintenance and servicing work, internal re-configuration or upgrade. A top-hinged, bottom lift-up side panel 51 acting as a tailgate may also be used to provide some shelter to personnel working on internal components. Tools, cable spools, wiring jump leads and other servicing kit (not shown) may be secured to the insides of housing walls.

Ventilation louvres 65 or other local perforations are incorporated in various housing panels, to allow venting and cooling air through flow; heat dissipation from internal components can be used to promote an internal convection current and (re-)circulation ; side wall cut-outs 53 are also fitted for mounting of service fixtures and fittings, such as outlet sockets 18, control and readout panels 62.

In this configuration an AC power inlet socket 66 is fitted in one end panel for connection through a fly lead with plug (not shown) to an external AC supply, such as a local mains (not shown) or an engine driven generator 17, for convenience of internal battery 12 top-up replenishment re-charge.

A marginally elevated 'safari' roof 55 is fitted as an over-cover, rather like a tent fly-sheet, to create an air pocket and overhead circulation path for ambient air or wind, to bolster ventilation, and also able to capture slipstream in a towable trailer-mounted variant for postoperative cooling, whilst preventing excessive ingress of water or contaminants whilst in use or in transit.

A folded, pressed or stamped sheet metal construction can be employed, such as with turned (down) marginal edges for local stiffness and to create a peripheral boundary edge strip 54 for mounting end panels. Internal cladding might be uses as heat and/or sound insulation and to suppress condensation, which might otherwise corrode electrical contacts. Synthetic plastics materials may supplement or substitute for metal panels; as, say, a large unitary moulding with bespoke local profiling around inner content. A corrugated or fluted panel profile could promote stiffness and surface water shedding and drainage. Tools etc may be conveniently stored in the internal recesses of such corrugations. A unitary or sub-divided format allows surface mounting of other elements, such as the solar PV panel array of Figure 6. The cover housing 50 surmounts and is directly fastened to the chassis 45, but supplementary intermediate support frames or ribs may be incorporated. A closed format shown conceals and protects contents, but local open or partially infilled, such as rigid metal or fabric mesh, sections can be used for ease of internal inspection. A tethered inflatable balloon sheath fabric tent canopy could serve for extreme weight-saving and as a sun screen in high ambient temperatures. In cold climes internal heat dissipation could be harnessed to warm a side awning for operations personnel. Spare heat may also help inflate a hot air balloon canopy. Overall, the housing 50 provides weather-resistant, if not necessarily totally weather or waterproof, protective contents shield, such as against prevailing wind, rain shower downpour and driving rain. Top side edge channels, flutes gullies and down pipes (not shown) can be used to disperse and carry away excess rainfall. For extreme exposed environments hermetically- sealed external housing or subsidiary internal barrier membrane, zip or tie closure waterproof bag casing for components, can be used to better resist water and/or gas penetration.

Supplementary straps, ties, tethers or other restraints can be fitted to the cover and /or the underlying chassis 45 for extreme weather, such as when the power module 11 is serving as a temporary emergency power supply when mains power lines have been brought down by bad weather. Hermetic sealing of components or assemblies could be provided for specialist exposed or high security, anti-tamper duty.

Figure 6 sequence shows a collapse-fold extendable solar PV panel array 60 configured as a series of individual panels 71 intercoupled in tandem through side frames 72, 73, 74, themselves secured by travel limited damped rotary action pivots 76, 77. A mid-set underlying mounting bracket 68 allows the panel assembly to swivel for direction to the direction of the sun, with the panels 71 set a shallow pitch angle to the horizontal.

In this particular construction a centre panel is mounted upon a canted central swivel frame 68, with out-fold panels 71 at opposite ends. A lower panel 71 is supported by side arms 74 with offset pivot to a central panel frame 73. An upper panel 71 at the opposite end is set upon side arms 72 with a dog-leg offset end profile, so that the outboard panels 71 can infold in turn over the middle panel 71 , with the lower panel 71 as an intermediate inner sandwich filling and an upper panel 71 as a final overlay. A central pivot boss 79 can be fitted to a telescopic mast tube (not shown) for vertical elevation way above the housing 50.

Figure 6A shows an upper plan view of an extended panel deployment upon opposed side arms and intermediate pivot shafts 75. Figures 6B1 and 6B2 show side elevations of panel 71 support upon a bracket 68 with a swivel mounting 79 to the roof of housing 50. Figure 6B1 shows of an extended out-fold panel deployment. Figure 6B2 shows panel infold and mutual stacked overlay. Figure 6C shows a local sectional detail of bracket interconnection through a pivot shaft 75 (plain bush) bearing 77 and (disc / pad) damper 76. Figure 6D shows a series of side bracket side elevation, and plan views.

The power module 11 is set to make judicious and efficient use of primary available power sources. As such it can select and arbitrate between power sources and institute partial power draw down from a selection of one or more, with the selection proportion changeable with circumstance. Thus, say, in a default 'decision- tree' or chain, mains power can be chosen over generator power to conserve limited generator fuel supply.

In one particular implementation, a version of the converter units 14 can accept two discrete AC input sources and decide which to employ. The presence of mains at first input AC1 might cause the generator at a second input AC2 to be turned off by means of a stop-start signal and vice versa. The AC inputs could be different or isolated phases.

The power module 11 can pay attention to the nature of individual power sources. Thus an engine driven generator 17 is more efficient run at constant speed, so draw-down from it can be adapted accordingly. Wind and to a lesser extent water turbine power fluctuates 'naturally' with ambient weather conditions and terrain topography and is inherently more volatile and unpredictable than, say, 'artificial' generator power. Solar PV array power is also variable 'naturally' with the weather and available sunlight throughout the day, but is predictably higher around mid-day. If a certain power is drawn directly from a generator to a load, a reduced amount may be diverted to or available for battery re-charge. This might be referred to as 'opportunity charging'. However, a cycle of occasional partial charge and discharge can help maintain battery 12 condition; particularly if a full charge is achieved periodically. The power module 11 can be configured to optimise and maintain battery condition by timing of charge and discharge.

A 'smart' generator control mode, with programmable intelligence, also optimises use of an (engine driven) generator 17 to compensate for changes in demand. At one extreme of low demand, it may be inefficient to run the generator 17, so it might be shut down in favour of battery 12 derived power, say through inverter(s). In a plot or graphic map of daily domestic demand peaks are relatively rather and short-lived, with the majority low level demand, more readily met from a battery 12 reserve. The power module 11 can be configured to reduce generator 17 dependence. Availability of solar PV power, wind or water turbine alternatives also help with this. Use or load demand patterns need not be known in advance for the power module 11 to cope with an immediate situation, but an accumulated recorded history could be applied to expert learning system to derive a predictive behavioural model. Such data can be collected using GSM cell phone network or ethernet based communications module and usage pattern 'learned' to enable control parameters to be more accurately adjusted or tune.

Input power from an external resource can be AC or DC, or a mix. AC can be single or polyphase in either input charge or output delivery. Thus, say 3-phase mains charge received at one voltage can be converted in an internal inverter / charger 14, then stored in the internal battery 12 as a DC reserve charge and output either as DC or back through an inverter / charger14 as single-phase AC power at another voltage. A polyphase, say 3-phase, AC output could be achieved through a switched mode inverter / charger 14 grouping. The power module 11 can assess load demand character, say if a load is resistive and/or reactive or requires higher voltage with lower current or lower voltage with higher current and adjust an individual delivery output accordingly. Load diversity might span from a mains voltage transformer winding to a low DC voltage for an electronic device. Multiple discrete tailored outputs can be produced for multiple different individual loads, again with a mix of AC / DC, voltage or current capability. Otherwise separate outputs can be applied together to a common load, for better use of internal current carrying capacity without overloading respective local circuitry. A DC step-up or or step-down can be accommodated, say, with an intermediate successive reversed AC conversion. The internal fusing or trip switches can adjust to suit load diversity, with different 'tolerance' to overload or short-circuit. The internal DC operating voltage can reflect battery type and an integer multiple of inherent battery cell voltage; by selective battery cell cluster different overall DC voltages can be secured. In the present example, an overall 48V DC operating voltage has been used as a compromise capable of delivering more power without undue current draw from the battery resource.

The supply and demand balance is variable with circumstances. Power resource allocation to load is by brokerage and arbitrage to reflect multiple and possibly conflicting influences. Prioritised and phased or staged load shedding is implemented if demand load exceeds power available from combined external and internal sources. Loads are selectively reinstated in priority ranking when power becomes available. In the interests of sustainability, 'environmentally-friendly' mode load shedding can be implemented to prolong the use of non- polluting or relatively 'green energy' internal battery power without calling upon a combustion by-product pollutant engine-driven generator. A 'considerate' load shedding program, such as prioritising safety such as emergency lighting over heating, may also encourage more judicious demand. A power module 11 might generate automated audio visual prompts on this. A facility to 'read and interpret' a load can be implemented electronically such as by recognising a reactive phase lag or power factor, along with the severity and duration of demand. Thus an electric power shower could be differentiated from a cooker element. An electric appliance motor should also be readily recognisable. A store of load characteristics could be used to help recall and match loads with standard or past experience. Power delivery management through multiple lesser capacity individual cable feeds can also be effected in a power module 11. Extreme loads, such as with industrial plant or equipment could be serviced by allocating one or more power modules 11 to individual phases of a polyphase feed.

A diversity of battery types can be accommodated in a common overall circuit, with a facility to discriminate between battery types and to select the most appropriate, individually or in combination, to address a particular demand, whose character and duration would also be assessed ; with battery selection qualified by the respective charge level and anticipated time to re-charge, to preserve the overall longevity of supply. Battery condition and active or live performance, such as output voltage and stability, could also be (re-)assessed as charge is drawn, for continual revision of projected life at a level sufficient to serve demand. Intelligent switchable allocation and utilisation of resources can arbitrate between competing load or battery re-charge demands to preserve supply integrity and longevity.

A decision factor in battery usage is identification and selection of the most appropriate inverter / charger type and their harness individually or jointly with others. Thus a continual sample or polling of battery and inverter / charger is conducted in an ongoing usage regime. With changed circumstances, the decision on battery and inverter / charger allocation and combination mix can also be adjusted. Similarly, an ongoing diversity of different load demands, serviced through respective outlet sockets, can also be mixed, combined and matched with selected internal resources (re-)allocated as necessary. A quite complex decision matrix of factors can thus arise, with a computational module harnessed for decision and action.

When an external power resource becomes available, the system assesses its nature or type and capacity and predicts its likely consistency and overall available time, to make a decision to allow partial use for internal battery (re-)charge whilst allocating a balance or surplus to meet an actual load demand. That allocation priority might be re-balanced or reversed, with the load given precedence over battery top-up. This can be conducted in prescribed fixed or variable periods before switch-over to another allocation mode. With operational experience a more sophisticated and elaborate multi-tiered resource allocation and predictive demand and resource model can be built up.

A combined or dual-mode inverter / charger could incorporate sensing and decision-making capability. Thus, say, by provision of input and output port sensing, demand, whether for an external load or an internal battery could be monitored along with available external or internal power resource; with a capability of charging an internal battery while serving an external load or mediating or switching alternately between demands in an arbitration mode. Provision can be made for calling upon, substitution or sharing the burden with, one or more other inverter / chargers, should actual or projected demand exceed the capabilities of an individual unit. That is inverter / chargers could usefully communicate with one another, through a hard-wired umbilical cable link and/or local wireless network.

Batteries might also feature an intelligent input/output interface in accepting and/or meeting demand. Safety provision to inhibit over-charging or exhaustion might also feature. A temperature sensor could monitor battery activity, say to trigger an over-heat cut-off, or enable on-board cooling fans. Automated cooling, directly or through environmental circulation, could also be provided for other units, particularly those with vulnerable semiconductor components. Excess heat could also be captured in a heat sink or heat-exchanger and redirected for more productive purpose, such as operator environmental comfort, heating of hand-wash water for operatives, or applied thermocouples to generate modest device driver voltage or current.

Resource management could be expanded to multiple intercoupled power modules, with suitably rated interlink, 'fly-leads' or 'patch' cables to swap battery and inverter / charger associations, not only within, but between, otherwise discrete modules. Similarly, respective output sockets could be combined for co-operative operation to meet demand.

Temporary surplus power from internal batteries or other accessible external power sources such as wind or water turbines, routed through individual or grouped power modules could be synchronised with and fed back into a local mains grid for the benefit of a feed-in tariff.

Metered output for statistical record and /or user billing could be provided for all power module operations. This could also record all chargeable or third party supplier inputs, to compute an operating margin and as a possible basis for charging for equipment hire, by combining a standard rental time and delivery to and from site element with a user or consumable element.

The principal circuit block elements of Figures 1 , 2 and 3 could be adapted to provide such (re-)routing and other functionality. A programable master controller, with an optional remote command relay link through antenna 28, could direct subsidiary control sectors in bidirectional converter 14, AC input link 25, DC link 24, AC output link 26, monitor 27, etc. Motorised isolator, fuses and/or trip switches could be under command of the master controller.

An example module has 16kVA capability of up to 63A @ 230V ac at a frequency of 50Hz. with 33kWhr stored energy available with zero emissions and zero noise.

Battery features include maintenance-free, decade or more design life, abs plastics housing material, plate technology, very low internal gassing, very low self-discharge rate, measures against deep discharge, complete recyclability. Lead acid batteries could feature internal valves for gas. Discharge current range of 20-150A, with weight of 20-118kg, nominal capacity 200-1500Ah; nominal charge voltage 2.25 V/C;

In a particular configuration, a module housing 'facilities access and control' end face features various associated groupings or clusters. An input cluster features a 63A input socket receptacle alongside hard wired input portals. An output cluster features x4 32A output sockets along with an automatic start socket. An instrument cluster features a converter control, an emergency stop, along with input / output isolators. A solar connection cluster features a solar isolator along with solar photovoltaic (PV) input sockets.

Operationally, there are a series of connections to be made in order to operate the unit. In summary these are; power input, power output, earthing and remote start. Depending on specification, on some units there is also a data connection point to make programming changes.

It is not necessary to use all of the connections in order to operate the machine but some functions may not then be available.

For input connection it must be ensured that the input AC isolator is off. Input power is connected either by means of a 63A I EC 309 coupler/socket located in the input cluster, or by removal of the fitted gland plate. An input supply cable should be a minimum 3 x 6mm2. A recommended cable type is H07RN-F to BS 7919. It is possible to use a reduction adaptor to a lower capacity source if desired. The input supply must be fed from a source that is protected by an over-current device. A suitable input supply cable and adaptors are not supplied with the unit but can be obtained from your supplier on request.

For output connection it is advised to switch off the input protection devices before plugging in any output cable. Output power is connected by means of any combination of the 4 x 32A IEC 309 sockets. The output sockets are located in the output cluster on the side of the unit as shown in section 2.3.2. As an option, alternative combination of sockets can be provided. Out can also be hard wired using one of the entry glands provided on the input cluster connection plate.

For earth point provision it is strongly recommended that the unit is connected to a common ground/earth point, such as an earth stake (available on request from your supplier). There are two threaded holes on the base of the unit intended for use as earthing points. Please refer to local site regulations for confirmation of the appropriate steps to ensure compliance with earthing requirements.

Installers are strongly advised to familiarise themselves with any prevailing regulations for installation of power equipment such as BS7909:2011 for events or CMD regulations in construction and, of course, the requirements of BS 7671 :2008.

Earth electrode resistance should be as low as possible. It is recommended is earth resistance does not exceed 20 ohms. Reference is also made to the provisions of BS

7430:2011 code of practice for protective earthing in electrical installations. Earth electrode resistance should be regularly checked.

For a remote start facilityin order to utilise the automatic generator start function, it is necessary to first establish that the generator is compatible with a two wire automatic start/stop signal. The standard configuration is open to stop, closed to run. Before engaging the auto start function, it is necessary to check the status of the signal programming. It may be necessary to have the function of the switch re-programmed to suit the required parameters. The auto start lead can be plugged into the auto start socket. The cable ends should then be connected to the appropriate terminals at the generator or have a compatible connector fitted.

A data port provision allows access to the system for diagnostic or programming needs, by connection of a RJ45 UTP patch lead to a port in the instrument cluster or, if not present, by removing the converter panel and using the cable connecting the panel to the data bus.

Post connection checks are made after connecting the unit and before switching on, it is necessary to check that the connections have all been made securely and that all incoming cables are in good condition and free from snags or other mechanical hazards and that they are safe and secure at the point of source or delivery of power.

To turn the machine on, the toggle switch on the converter remote panel is switched to the on position. Within a few seconds, the unit will switch on and the green inverter on LED will illuminate.

To provide power to the output sockets, it is necessary to make sure the output protection devices are switched to the on position.

In the on position, the unit will automatically switch between inverter and charger mode depending on the availability of input power. In charger only mode, the inverter function of the unit is disabled but the charger works normally with power also being switched directly through the unit.

The unit is switched off by moving the toggle switch on the converter control panel to the central off position. For maintenance charging, the unit can be switched to the charger only position. In this mode the inverter operation is disabled. The unit can be charged from an external source, but in the event that power is lost, the inverter will not activate. This will help to avoid battery discharge whilst in storage.

In addition to the on/off controls and the power isolators/protection devices, the unit has two monitoring instruments. There is a battery monitor and a converter control panel.

Battery monitor - the battery monitor provides information on the condition of the battery. Pressing the select button will scroll the display through five data items:

• SoC - state of charge displayed as a percentage of full charge

· CE - consumed energy displays how many amp-hours have been taken from the battery

• TTG - time to go gives an estimate of how long the system will continue to provide energy at the present rate of discharge until the battery reaches the discharge floor (NB: this level by default is 50% remaining capacity)

· V - battery voltage

• I - battery current (positive readings represent charging, negative represent

discharge)

A converter control panel displays status information on the converter circuits. Warning and alarm indicators provide feedback on fault conditions.

There is the possibility to utilise a number of advanced functions as well as being able to make adjustments to operating parameters to adapt the performance of the machine to suit specific circumstances.

The module has a so-called 'Input Assist' feature option. This feature can be turned off if desired (this requires computer interface). The primary objective of the feature is to prevent overload of the connected source of power. For correct operation, it is necessary to set the input current limit. The rotary knob on the converter control panel allows adjustment of the threshold.

Firstly, the maximum desired current that can be drawn from the supply must be established. Turn the adjustment on the panel until the desired figure is visible in the digital display. For example, if the supply to the unit is covered by a 32A MCB, adjust the knob until '32' is visible in the display. Input current will now be limited to 32A regardless of how many amps are demanded by the load.

The effect of this feature is to automatically and dynamically adjust charging current as the power demanded by the load varies.

In an example, if the dial is set at 32A and the output load requires 20A, then 13A is available to power the battery charging function. If the load rises to 25A, then 8A is available to charge the battery and so on. If the load requires 32A then the charge function is suspended. If the load requires 40A then the deficit of 8A is 'borrowed' from the battery. When the load falls back below 32A then the unit resumes charging the battery and replenishes the power that was borrowed.

The input assist setting can be hard programmed into the unit, so that local adjustment cannot be made. This requires a software adjustment to be made. In this condition, the digital display shows 'Ac1 '. The feature can also be disabled.

The unit can be connected such that it can provide an automatic stop start signal for an allied generator. The basis upon which this signal is activated can be adjusted around a broad set of parameters.

For example, it is possible to set the start signal to be activated at a designated state of charge and/or a designated level of load sustained for a particular period of time. The signal can then be set to keep the generator running for a minimum period before deciding to turn the machine off.

All of the parameters can be adjusted. It is also possible to invert the signal from a normally open to a normally closed signal, the signal can be used to activate an alternative function to starting a generator if desired.

Changes to the programmed features is only possible by means of connecting a computer and with dedicated software. A GSM monitoring feature option provides a means to access real time and historical detail of performance by means of access through a web portal. For the system to function it is necessary to insert a SIM card ; such as a contract based pay monthly card is obtained from a preferred network provider. It is also possible to make programming changes to the unit through the GSM portal.

A solar PV input feature provides the means for an external solar PV array to be connected to the machine for the purpose of charging the batteries. A stow-able, over-folding panel top mount Solar PV module is available as an option or a user supplied discrete system can be connected provided that it conforms to the defined specification below.

In either case, the solar PV array is connected to the machine by means of either or both pairs of MC4 connectors on the solar PV connection cluster shown below. There is a maximum input voltage (max Voc) and power (max Wp) that must be observed. Exceeding the maximum values may result in malfunction and will invalidate warranty.

The following connection procedure should be followed :

Ensure that the isolator switch is to the OFF position before connecting or disconnecting an array.

Step 1 - Ensure that the isolator switch is to the OFF position before connecting or disconnecting an array.

Step 2 - Connect the array to the MC4 panel connectors on the solar cluster observing correct polarity.

Note: If connecting input to both pairs of MC4 connectors, it is essential that both array 's share the same voltage specification. Damage may occur to the connected solar modules if this is not observed. Each pair of connectors is able to handle a maximum of 2kWp input.

Step 3 - Turn the Isolator switch to the ON position.

Step 4 - Before disconnecting the solar PV array, ensure that the Isolator Switch is turned to the OFF position.

Once the array is connected, under appropriate daylight conditions, proper functioning can be verified by isolating the AC output of the machine and observing a positive charge current and corresponding rise in battery voltage.

SOLAR PV input specification :

Minimum Input Voltage 50Voc (operation) 55Voc (start-up)

Maximum Input Voltage 150Voc

Maximum input power 4000Wp (2 x 2kW)

For system maintenance, it is important to maintain a charge regime that ensures the battery receives a full charge periodically. It is not practical or efficient to necessarily carry out a full charge on every cycle. Long term battery life does, however, rely on a full charge being carried out at least every 4 or 5 cycles.

The battery monitor records the charge routine and it is possible to interrogate the instrument and extract data on how frequently a full charge has been executed.

Before putting the unit into storage, it is advised that the battery is given a full charge. This is achieved by connection to a power supply and leaving the unit switched on until the instrument shows 100% and that the yellow 'float' LED on the converter control panel is illuminated.

Example specification

Models 572/16 - 420/1 0

Output Power (230V 50Hz 1 0)

Continuous 16kVA - 10kVA

Peak (5 seconds) 32kVA - 20kVA

with max input source connected - continuous (max) 39kVA(55kVA) 23kVA (33kVA)

Maximum Input A @ 230V 50Hz (continuous) 100A / 23kVA

Maximum Output A @ 230V 50Hz (continuous) 169A - 140A Maximum Output A 5 seconds 239A - 186A

Useable stored energy (to 80% DoD) 22kWhrs - 16kWhrs

Battery Type SLA Gel PzV - SLA AGM

Battery design life 8-10 years - 3-5 years

Autonomy (maximum) in silent mode @20oC: @ 20% average load 7h - 8h; @ 50% average load 3h - 3h 30m; @ 80% average load 1 h 30m - 2h;

Typical recharge time (from 80% DoD): to 80% SoC 4h - 5h; to 100% SoC 8h - 9h;

Enclosure details: Weight 1398 Kg - 807Kg; Length 1450mm; Height 1150mm; Width 850mm;

Ingress Protection of outer case IP34 Suitable for outdoor use;

Standard Finish Epoxy Powder Coat RAL 9016;

Noise levels: Inaudible above background;

Heat rejection (maximum) 3200W 2000W;

Input connection AC1/AC2 IEC 309 63A / 4x hard wire 8mm stud;

Output connections: AC1 4 x 32A IEC 309; AC2 4 x hard wire 8mm stud;

Instruments/controls: System status; Battery condition; RJ45 socket for diagnostics and adjustment; Battery main isolator; Input & Output MCB's; Programmable generator auto-start signal;

Optional features: Stackable modules; GSM remote monitor and controlled Fitted as standard (requires SIM) Battery extension module; Harsh environment pack; Road Tow trailer kit;

Component List

11 power module

12 battery (pack)

13 input isolator switch

14 inverter / charger: <bi-directional converter>

15 solar PV panel array

16 output isolator switch

17 external i.e. (diesel) engine driven generator

18 power outlet socket(s)

19 AC inlet socket

20 terminal connector block

21 (dual pole) output isolator switch

22 external generator engine fuel tank sensor

23 solar regulator

24 DC link + sensor

25 AC input link, sensor + isolator switch

26 AC output link, sensor + isolator switch

27 monitor

28 GSM antenna for web based interface

29 multi-mode (battery) monitor

30

31 battery monitor

32 master switch

33 connector terminal pole

34 output isolator switch

35 connector terminal pole

36 fuse link

37 fuse link

38 shunt 39 fuse link

40

41 battery tray

43 battery bulkhead

44 inverter bulkhead

45 base chassis

46 cable routing aperture

47 instrument mounting plate

48 partition

49 earth stud

50 housing

51 demountable side panel / cover

53 aperture / cut-outs

54 end edge flange

55 safari roof overlay cover

60 folding solar PV panel array

61 auto start socket

62 gauges, switches, fuses, etc

63 earth stud

65 louvres

66 AC power inlet socket

67 side bracket arm

68 gimbal mount

69 side bracket arm

70

71 panel

72 side arm bracket

73 side arm

74 side arm bracket

75 pivot tube

76 pad damper

77 bearing bush

78

79 swivel

80

81 tapping line

82 sensing terminal

83

84

85 feed line

86 common pole

87 AC input

88

89 AC output

90

91 AC output

93 DC input / output

95 voltage / polarity sensor

96 interconnection

Claims

1 .

An electrical power module (11 ), comprising

an internal self-contained DC battery power resource (12)

configured as a default operational reserve,

an inverter and/or bidirectional power converter 14,

an AC and/or DC power input or charger circuit,

an AC and/or DC power output delivery circuit,

an interface for coupling to an external AC or DC power supply,

a control for selectively applying external power for internal battery (re-)charge, whilst allowing output draw down of internal DC charge.

2.

A power module of Claim 1 ,

configured with a DC battery pack

with individual battery cells grouped in clusters

for selective tapping of individual or collective cell voltage

to provide an adjustable DC voltage output

through one or more output sockets.

3.

A power module of either preceding claim,

with an input socket for external AC power,

such as a local mains supply, a engine driven generator, wind or water turbine, routed through an inverter / charger

to (re-) charge an internal battery pack.

4.

A power module of any preceding claim,

with an input socket for external DC power,

such as from a solar PV panel array,

routed to (re-)charge an internal battery pack.

5.

A power module of any preceding claim,

configured to balance, offset or match supply and demand,

of multiple diverse external power sources

with multiple diverse external loads,

using an internal battery pack as an optional default routing and/pr conversion intermediary.

6.

A power module of any preceding claim,

with a battery condition or charge level monitor,

for an internal battery pack.

7.

A power module of any preceding claim,

with an output for command signals,

to external facilities or power sources,

such as to trigger operation of an engine driven generator

according to load demand.

8.

A power module of any preceding claim,

with mutually screened internal compartments

for battery and inverter / chargers,

configured on a mobile base chassis,

such as a road vehicle towable trailer

surmounted by a ventilated housing,

with side wall apertures for monitoring gauge and connection services,

and /or demountable access panels,

beneath an elevated safari style roof canopy section.

9.

A power module of any preceding claim,

with a deployable, collapse-fold, solar PV panel array,

to provide an external DC power source

for (re-)charge of an internal battery.

10.

A power module of any preceding claim,

with a remote radio, cell phone or internet link,

for sensing, monitoring and control commend signals

of external power sources and internal battery condition.

11.

A power module (11 ),

configured as a default operational reserve,

for self-contained, stand-alone operation,

or in conjunction with selectively harnessed external power supply resources, including any individually or in selective combination

of engine driven generators, local mains supply, wind or water turbines and solar PV panel arrays,

with an internal re-chargeable DC battery power resource (12),

an AC and/or DC power input or charging circuit,

an AC and/or DC power output or delivery circuit,

an inverter and/or bi-directional power converter 14

in or operatively between the input and output circuits,

an interface for coupling to an external AC or DC power supply,

a control circuit for selectively applying external power for internal battery (re-)charge, whilst allowing output draw down of an internal DC charge;

the control circuit allowing recognition of a diverse mix of power resources

and automatic differentiation between various load demands,

with the supply and demand balance variable with circumstances;

prioritised and phased load shedding being implemented if demand load

exceeds power available from combined external and internal sources;

with loads selectively re-instated in priority ranking when power becomes available, with adjustable allocation of external power for battery re-charge

automatically in relation to load demand,

to preserve continuity and longevity of supply.

12.

A standby power supply or power network sub-station,

with a plurality of discrete individual power modules of any preceding claim,

co-operatively intercoupled in a switchable intelligent managed power network or matrix, for selective individual or joint operation,

to meet external load demand,

by supply of draw-down voltage, current or power.

13.

A power module of any preceding claim

harnessed or coupled to an external power supply,

such as a local mains grid, an engine driven generator,

a solar PV panel array, a wind and/or water turbine generator

and configured for selective prioritised coupling to a load demand.

14.

A power module of any preceding claim,

with diverse battery types, output voltages and/or capacities,

configured for selective prioritised connection with

a diversity of inverter chargers,

for battery drawn down or re-charge.

15.

A power module of any preceding claim,

coupled to one or more other power modules

in a local power network or grid

and configured for selective prioritised use of modules

individually or in combination.

16.

A power module of any preceding claim,

configured to automatically and dynamically adjust charging current as the power demanded by the load varies,

with provision to set an input current limit threshold

to inhibit overload of a connected source of power.

17.

A power module of any preceding claim

with a safety over-ride provision to a fuse or relay trip,

configured as an emergency disable or shut-off switch facility operable to shut down and isolate the module

from both the load and an external mains or generator power source and to supercede any regular control settings

with provision for reversal to re-enable the module in a single action.

18.

A power module of any preceding claim,

configurable for either single or multiple phase AC phase

for greater power handling capacity

with selective load allocation

to a selected phase or collectively over multiple phases.

19.

An electrical power module of any preceding claim

configured as an intelligent pro-active intermediary

adaptable with circumstances

between a passive internal battery DC power source

an external load or demand

and an external power supply

to allow controlled battery drain to service the load

with selective call upon external supplies as and when available.

20.

A power module of any preceding claim

configured withlntelligent switchable allocation and utilisation of resources to arbitrate between competing load or battery re-charge demands to regulate and preserve supply integrity and longevity.