Power supply

Abstract

Disclosure is provided of a power supply (100) and a method (S10) of controlling the power supply (100). A battery pack (1) is configured to supply (Si l) electrical power. A glycerine generator (2) is configured to supply (S13) electrical power if the battery pack (1) has become depleted (S12), wherein the glycerine generator (2) is configured to recharge (S14) the battery pack (1). A determination unit (3) is configured to determine (S16) whether a demand on the power supply (100) exceeds a threshold that can be supplied by the glycerine generator (2), resulting in a deficit of electrical power that cannot be supplied by the glycerine generator (2). A control unit (4) is configured to control (S17) the battery pack (1) to supply the deficit of electrical power that cannot be supplied by the glycerine generator (2). As a result, the power supply (100) is capable of satisfying a high demand by sharing the load between the battery pack (1) and the glycerine generator (2).

Description

[0001] POWER SUPPLY

[0002] Technical Field

[0003] This disclosure relates to a power supply. In particular, this disclosure relates to control of the power supply in order to satisfy demand.

[0004] Background

[0005] There’s a growing expectation for businesses to harness renewable energy solutions, while ensuring that their work remains profitable. An ambition shared within industry by customers, employees, and regulators is for the environmental impact of industrial processes to be mitigated. When working on sites that have no access to grid power, it’s typical for a temporary electricity supply to be provided, in order to power tools, lighting, and facilities. There has been a long felt need to improve the temporary power solutions that are available in the market. Innovation is to be found in the ways in which temporary power is supplied within various industries, such as construction, rail, highways, waste management, water management, home building, and onshore / offshore energy.

[0006] The demand for power varies during the day, and at different stages of a project. Customers have an expectation that power supplies will satisfy their demands for high power. Renewable energy sources (e.g., solar power & wind power) often do not provide enough energy to provide the full amount that is demanded by the consumer, and are often unreliable, being dependent on the time of day and weather conditions. The variability of energy sources presents challenges in satisfying the power demands that are placed on the power supply. Temporary power supplies mitigate for this variability by storing energy in batteries. When the demand for power is low, the batteries are charged. If the renewable energy source is not sufficient for meeting the demand, then energy that has been stored in the batteries is released, in order to satisfy the demand.

[0007] Eventually, batteries will become depleted during times when the demand on the power supply is particularly high for sustained periods. When the batteries become depleted, backup generators are often made available to replace the renewable source of energy. The backup generators can be used to satisfy the demand for energy, with any surplus energy being used to recharge the batteries of the power supply.

[0008] It is common for backup generators to consume diesel fuel. As the demand for power is increased, the amount of diesel being consumed can be increased, in order to satisfy the demand for more power. Burning diesel results in harmful emissions such as carbon dioxide, carbon monoxide, nitrogen oxides, sulphur dioxide, hydrocarbons, and other pollutants. There is a growing expectation for backup generators to be provided that are less harmful to the environment.

[0009] A potential option is to provide a backup generator comprising a hydrogen fuel cell. The combustion of hydrogen results in the emission of water vapour and air, thus offering a much more environmentally friendly solution. However, for many applications, hydrogen generators are dismissed due to them being prohibitively expensive.

[0010] It’s well known that carbohydrates such as glycerine can serve as a fuel source. However, carbohydrates tend to be quite problematic to burn, in comparison to hydrocarbons. The high combustion performance of hydrocarbons means that the energy conversion can quickly be ramped up by increasing the amount of hydrocarbon that is combusted. In contrast, the relatively low combustion performance of carbohydrates makes it difficult to ramp up energy production during times of peak demand. As a result, generators that are fuelled by carbohydrates (e.g., glycerine) tend to be configured so that they operate at a constant rate, rather than having a bum rate that is selected based on demand.

[0011] Gycerine (C3H8O3), which is also known as glycerol or glycerin, is typically refined from biomass. When burned, glycerine produces emissions that are less harmful compared to fossil fuels such as diesel. Glycerine is an oxygenated fuel, and due to complications of burning neat glycerine, instead glycerine is often used as an additive to hydrocarbon fuels. As a consequence, this has resulted in lower the nitrogen oxide emissions. There is a growing expectation for businesses offering renewable energy sources to move away from backup generators that rely upon hydrocarbon fuels.

[0012] Difficulties are encountered when attempting to burn neat glycerine, due to its combustion performance being relatively poor compared to hydrocarbons. In addition, the high viscosity of glycerine makes it more difficult to handle compared to hydrocarbons. Furthermore, fuel degradation of glycerine is known to cause damage during combustion and during storage. All of these challenges have resulted in a bias within industry against the provision of generators that run on carbohydrates. Thus, if an attempt were made to replace a diesel generator with a more sustainable alternative, it would not be obvious to select a glycerine generator.

[0013] Summary

[0014] Aspects of the present invention are set out by the claims. Further aspects are also described.

[0015] According to a first aspect, there is provided a power supply. The power supply comprises: a battery pack configured to supply electrical power; a glycerine generator configured to supply electrical power if the battery pack has become depleted, wherein the glycerine generator is configured to recharge the battery pack; a determination unit configured to determine whether a demand on the power supply exceeds a threshold that can be supplied by the glycerine generator, resulting in a deficit of electrical power that cannot be supplied by the glycerine generator; and a control unit configured to control the battery pack to supply the deficit of electrical power that cannot be supplied by the glycerine generator. Advantageously, the power supply is arranged so that during use, a high demand for electrical power can be satisfied by both the backup generator and the battery pack. This makes it possible to provide a glycerine generator that serves as a backup generator, in the event that the battery pack has become depleted.

[0016] Optionally, the control unit is configured to control the battery pack to supply the deficit of electrical power that cannot be supplied by the glycerine generator while the determination unit determines that the demand on the power supply exceeds the threshold that can be supplied by the glycerine generator. Advantageously, the battery pack will continue to supply the deficit until the demand for electrical power no longer exceeds the threshold that can be supplied by the glycerine generator.

[0017] Optionally, the power supply further comprises an inverter configured to control operation of the battery pack and the glycerine generator based upon an instruction received from the control unit. Advantageously, the inverter is configured to keep the load stable. This stability is achieved by selecting settings of the inverter to ensure that it draws a consistent supply of energy from the glycerine generator. The control unit is configured to instruct the inverter to start and stop, with operation of the inverter being local to the inverter. Functionality of the determination unit, the control unit, and the inverter may be achieved by a single component, or may be performed by separate components of the power supply. Optionally, the determination unit is configured to determine whether the battery pack has been recharged, and the control unit is configured to control the battery pack to resume supplying the electrical power if the battery pack has been recharged. Advantageously, the glycerine generator continues to serve as a backup generator until the battery pack has been recharged. When the battery pack has become recharged, it will take over from the glycerine generator.

[0018] Optionally, the power supply is self-contained to include the battery pack, the glycerine generator, the determination unit, and the control unit. Advantageously, the power supply is provided to the consumer as a single unit that can be installed in place ready to provide electrical power. The determination unit and the control unit may form part of a battery management system. The power supply may further be self-contained to include the inverter, which may include the determination unit and control unit as integral components.

[0019] Optionally, the glycerine generator serves as a backup to a renewable energy source. Advantageously, if the supply of power from the renewable energy source has become depleted, then this is taken over by the glycerine generator, which is more environmentally friendly compared to a backup generator configured to burn hydrocarbons.

[0020] Optionally, the power supply further comprises a solar panel configured to provide electrical energy for recharging the battery pack. Optionally, the power supply is configured so that during use, the solar panel is arranged at an angle to the horizontal. Advantageously, the power supply includes an integral array of photovoltaic cells, which are configured to serve as a renewable source of electrical energy. The solar panels are arranged at an optimal angle to the sun, in order to achieve a maximum level of power generation. Furthermore, arranging the solar panels at an angle ensures that they will be cleaned by rain.

[0021] Optionally, the power supply further comprises a cabin configured to house electrical components of the power supply. Optionally, the cabin has a sloped roof. Optionally, the cabin has a triangular cross section. Advantageously, the cabin serves to provide all of the electrical components as part of a self-contained power supply. Thus, the power supply may be installed with solar panels which are arranged at an optimal angle.

[0022] According to a second aspect, there is provided a method of controlling a power supply. The method comprises: supplying electrical power using a battery pack; supplying electrical power using a glycerine generator if the battery pack has become depleted, and recharging the battery pack using the glycerine generator; determining whether a demand on the power supply exceeds a threshold that can be supplied by the glycerine generator, resulting in a deficit of electrical power that cannot be supplied by the glycerine generator; and controlling the battery pack to supply the deficit of electrical power that cannot be supplied by the glycerine generator.

[0023] Advantageously, the power supply is controlled so that during use, a high demand for electrical power can be satisfied by both the backup generator and the battery pack. This makes it possible to provide a glycerine generator that serves as a backup generator, in the event that the battery pack has become depleted.

[0024] Optionally, the method further comprises: determining that the demand on the power supply no longer exceeds the threshold that can be supplied by the glycerine generator; and controlling the battery pack to stop supplying the electrical power if the demand on the power supply no longer exceeds the threshold. Advantageously, the battery pack will continue to supply the deficit until the demand for electrical power no longer exceeds the threshold that can be supplied by the glycerine generator.

[0025] Optionally, the method further comprises: determining whether the battery pack has been recharged; and controlling the battery pack to resume supplying the electrical power if the battery pack has been recharged. Advantageously, the glycerine generator continues to serve as a backup generator until the battery pack has been recharged. When the battery pack has become recharged, it will take over from the glycerine generator.

[0026] According to a third aspect, there is provided a program which, when executed, causes the power supply to perform a method according to the second aspect. Advantageously, the program contributes software which can be used to control the power supply.

[0027] According to a fourth aspect, there is provided a computer-readable storage medium storing a program according to the third aspect. Advantageously, the storage medium is installed with the program configured to control the power supply. The program may be installed one or more electrical components of the power supply, such as the inverter.

[0028] Brief Description of the Drawings

[0029] Embodiments will now be described, by way of example only, with reference to the accompanying drawings, in which:

[0030] • FIG. 1 provides a perspective view of a power supply; • FIG. 2 provides a schematic view of the power supply, illustrating the transfer of energy between electrical components;

[0031] • FIG. 3 provides a cross section view of the power supply;

[0032] • FIG. 4 illustrates direct current wiring of the power supply;

[0033] • FIG. 5 illustrates further detail of the direct current wiring of the power supply;

[0034] • FIG. 6 illustrates alternating current wiring of the power supply;

[0035] • FIG. 7 illustrates how electrical components of the power supply are arranged; and

[0036] • FIG. 8 provides a flow chart illustrating a process for determining how electrical power can be supplied by the power supply.

[0037] Detailed Description

[0038] Various exemplary embodiments, features, and aspects are described in detail below with reference to the drawings.

[0039] The present disclosure is exemplified by a self-contained solar / hybrid generator that uses glycerine as backup generator fuel source. The solar hybrid power systems and the self- contained hybrid power systems can be used to provide off grid power to clients who require temporary power and do not have access to a DNO (distribution network operator) grid supply.

[0040] This innovation relates to a self-contained hybrid power system that is configured to recharge the system when the batteries are low. Commercial applications include the provision of a self- contained hybrid power lighting system, a self-contained hybrid power CCTV (closed-circuit television) system, and a self-contained welfare cabin (both mobile and static). For each of these commercial applications, the backup generator is configured to recharge the system when the batteries are low.

[0041] Using a glycerine generator as the backup generator instead of a diesel generator reduces the carbon emissions, which allows users of the power supply to reduce their carbon emissions when implementing a solar hybrid power systems or a hybrid power system. The market for solar hybrid and hybrid power systems is growing rapidly as companies seek to reduce carbon emissions, and therefore this is a rapidly growing market.

[0042] Until now a low emission backup generator within a solar-hybrid and hybrid system was only possible using hydrogen as a backup fuel. Hydrogen is currently extremely expensive as a fuel source compared to diesel or HVO (hydrogenated vegetable oil). The supply chain for green hydrogen is not yet established within the UK. It is estimated that this supply chain will take around 7-10 years to become established.

[0043] This means that hybrid and solar hybrid systems currently use diesel or HVO as a backup fuel source. Diesel emits 2.68kg per litre burned, leading to high carbon emission from the construction sector. The construction sector current accounts for 33% of UK’s carbon emissions.

[0044] Glycerine as a fuel source in a generator has been created previously. However, glycerine generators can only be run at a stable load, meaning they have very limited use in the temporary power market, whereas load demands are almost always dynamic. This has meant that this technology has not been adopted by the temporary power market in the past 20 years, showing the previous limitations of the glycerine generator as a standalone product.

[0045] Glycerine generators are known to operate optimally when they are configured to provide a stable load. This is achieved by the power supply including inverters that are configured to draw a stable load from the generator. This allows the power supply to make use of a glycerine generator. The glycerine generator serves as a backup generator, in order to recharge the batteries when they have become depleted. As a consequence, the glycerine fuel reduces harmful emissions that are created, when compared to a traditional diesel generator backup.

[0046] The disclosed innovation provides a glycerine generator being run at a stable load to charge batteries (e.g., lithium batteries). The stored energy within the batteries is then linked to an inverter, in order for the batteries to be used to power the dynamic loads of a construction or infrastructure site. Thus, the glycerine generator serves as part of a self-contained power supply system.

[0047] The power supply includes inverters and a BMS (Battery Management System) which ensure that the generator is provided with a stable load, which allows it to operate efficiently and with the significant reduction in emissions.

[0048] The disclosed innovation provides an arrangement for which glycerine generators can be used as a backup power source, within solar-hybrid and hybrid power systems, for a variety of applications. This would not have previously been possible, and allows access for the temporary power market to have a backup fuel with significantly lower carbon and particulate emissions, while keeping fuel costs at a reasonable level (approximately 10% more expensive compared to HVO at the time of writing). There is an incentive for industry to accept this 10% cost increase, in order to enable low carbon temporary power, welfare, and lighting solutions, whereas hydrogen has not been widely adopted due to the high cost and supply chain limitations.

[0049] This innovation has applications to serving the temporary power, lighting, CCTV, and welfare market, offering a low carbon solution at a price that will allow industry to invest heavily in this technology.

[0050] FIGs. 1-7 provides various views of a power supply 100, and FIG. 8 provides a flow chart illustrating a process S10 for determining how electrical power can be supplied by the power supply 100.

[0051] FIG. 2 provides a schematic view of the power supply 100, illustrating the transfer of energy (E1-E7). The power supply illustrated includes a battery pack 1, a generator 2, a determination unit 3, a control unit 4, an inverter 5, an outlet 6, and an array of solar panels 7. The battery pack 1 includes a number of batteries. The generator 2 serves as a backup in the event that the battery pack 1 has become depleted of energy.

[0052] The power supply 100 forms part of a cabin 8, within which electrical components (1-6) of the power supply 100 are housed. The cabin 8 is generally triangular in cross section, having a sloped roof on which the solar panels 7 are arranged. The sloped roof of the cabin 8 helps to ensure that the solar panels 7 are presented facing the sun. The power supply 100 includes a number of solar panels 7 that are configured to provide electrical energy for recharging the battery pack 1. The cabin 8 can be customised based on the specific project, being installed with a bespoke number of solar panels 7, batteries 1, and generators 2. The power supply 100 can be modified during the course of a project, as the demand for electrical power changes. The cabin 8 illustrated in this example corresponds to a 20 ft x 8 ft steel shell that is fitted with solar PVs 7 on the sloping face.

[0053] FIG. 1 illustrates a flat side wall of the cabin 8 which includes an air vent, signage that advertises “Relocatable Renewable Energy”. The cabin 8 may further include branding such as “www.ThinkHire.co.uk”.

[0054] When setting up work site facilities, several portable cabins typically provide accommodation for workers. The power supply 100 has dimensions corresponding to a typical cabin, and so in addition to serving as the power supply 100, it may also contribute towards the accommodation space that is available to the workers. If the power supply 100 is arranged next to a cabin, or on the roof of the cabin, then electrical power from the power supply 100 can be used to provide the accommodation with electricity. Thus, applications of this off-grid power generator include lighting systems, CCTV systems, and welfare cabins.

[0055] The determination unit 3 monitors the demand for electrical power that is to be supplied to the load, as well as the supply of electrical power that is available from the power sources (1, 2, 7). The control unit 4 controls the supply of electrical energy by the battery pack 1 and the generator 2. The control unit 4 determines whether electrical power is to be drawn from the battery pack 1, or the generator 2. The inverter 5 is configured to execute instructions received from the control unit 4, in order to draw electrical power to satisfy demand on the power supply. The inverter 5 is configured to draw electrical power from the battery pack 1 and / or the generator 2, in order to supply the electrical power to the load via the outlet 6. The inverter 5 is also responsible for transferring electrical energy that is to be stored by the battery pack 1. Thus, the electrical energy flows from the inverter 5, to a contactor, to a distribution board, and then to the output sockets 6 (further detail of this is provided by FIG. 6).

[0056] This ensures that the supply of electrical power is arranged to satisfy the demand. If there is a surplus of electrical power, then the determination unit 3 ensures that electrical energy is stored by the battery pack 1. If there is a deficit of electrical power, then the determination unit 3 is configured to arrange for the supply to be increased. A deficit of electrical power may occur if the battery pack 1 has become depleted, or if the demand exceeds a maximum level that can be supplied by the generator 2.

[0057] The determination unit 3 and the control unit 4 operate to manage the power supply 100. The determination unit 3 and the control unit 4 may be consolidated as part of a single device, and may be further consolidated as part of the inverter 5. Alternatively, the management of the power supply 100 may be distributed to different components within the power supply 100. For example, the power supply 100 may include a battery management system (BMS) configured to manage the battery pack 1, and a generator management system (GMS) configured to manage the generator 2. Functionality of the determination unit 3 and the control unit 4 may be implemented by the BMS and the GMS. The outlet 6 includes a number of sockets. Each socket is configured to receive a plug of a device that is to receive electrical power from the power supply 100. Thus the devices receive electrical power from the outlet 6 via a cable. The solar panels 7 include photovoltaics (PV) which are configured to convert light energy into electrical energy. Each solar panel 7 includes semiconducting materials which exhibit the photovoltaic effect. The use of photovoltaic technology contributes to the mitigation of climate change by emitting much less carbon dioxide than fossil fuels. Once installed, operation of the solar panels 7 does not generate any greenhouse gases, with emissions being restricted to their manufacture, transport, and disposal.

[0058] The power source 100 is configured such that during use, energy (E1-E7) can be received from the energy sources (1, 2, 7), stored by the battery pack 1, and supplied by the outlet 6. Solar energy El is received by the solar panels 7, which is converted into electrical energy E2 and stored as chemical energy in the battery pack 1. When a load places a demand on the system, the inverters 5 draw electrical energy E3 from the battery pack 1. The electrical energy E4 is transferred to the outlet 6, with this electrical energy E5 being delivered to the load via electrical cables. If the battery pack 1 has become depleted, then the inverter 5 draws electrical energy E6 from the generator 2. This electrical energy E4 is transferred to the outlet 6, so that this electrical energy E5 can be delivered to the load. Any surplus electrical energy E7 is transferred by the inverter 5 to the battery pack 1, to be stored as chemical energy.

[0059] The inverter 5 converts electricity from 48 V DC to 230 V AC to the output 6, when it is inverting. When the backup generator 2 is running, it takes the 230 V AC from the generator 2, and passes it through to the end consumer loads, via the output 6. At the same time, it can charge the batteries 1. The inverters 5 are configured to draw a stable load from the backup generators 2. The inverters 5 are configured to take a stable load from the generator 2. Output sockets 6 get priority, and any excess will be used to charge the batteries 1. Three inverters (5a, 5b, 5c) are configured together to supply an overall output voltage of 415 V, three phase. The inverters are configured with overload protection, short circuit protection, and temperature protection.

[0060] During normal use, the inverter 5 draws direct current (DC) from the battery pack 1, and supplies alternating current (AC) to the outlet 6. When power is not being supplied by the outlet 6, the inverter 5 is configured to transfer direct current received by the solar panels 7 to be stored by the battery pack 1. When the battery pack 1 has become depleted, the inverter 5 is configured to transfer alternating current received from the generator 5, to supply alternating current to the outlet 6, with any surplus energy being supplied as direct current to charge the battery pack 1. When demand has exceeded a threshold that can be supplied by the generator 5, direct current is drawn from the battery pack 1 and the generator 5, with the inverter 5 being configured to supply this energy as alternating current to the outlet 6.

[0061] FIGs. 3-7 provide further details of the power supply 100. Main components of the power supply 100 include:

[0062] • Self-contained power system

[0063] • Solar PV

[0064] • MPPT Solar Charger

[0065] • Inverters

[0066] • Lithium battery system with individual BMS

[0067] • Glycerine backup generator to recharge batteries and provide power assist under high load conditions

[0068] • Remote monitoring, management and fault resolution

[0069] • System will provide power from the batteries aided by renewable energy from solar PVs, when the batteries are depleted the glycerine backup generator will automatically start and recharge system.

[0070] Internal components of the power supply 100 include:

[0071] • 3 Victron quattro inverters (features 5a, 5b, 5c)

[0072] • MPPT Solar Charger (feature 30)

[0073] • Lithium LFP battery bank (feature 1) containing an individual BMS for each battery module

[0074] • Backup Glycerine generator (feature 2)

[0075] • Cerbo GX and Panorama hardware for remote monitoring, setting adjustment, maintenance, software updates and configuration.

[0076] • Isolators (features 31, 31a, 31b), fuses (51, 52), MCCB’s, RCD’s, RCBO’s for system safety complaint with BS7671.

[0077] • System outputs 230V & 415V.

[0078] • System provides power from battery / solar, when batteries are depleted system will automatically start backup Glycerine generator to recharge batteries. • This reduces the fuel consumption compared to a standard diesel generator through load generator load efficiency gains.

[0079] FIG. 3 provides a cross section view of the power supply 100. The power supply 100 includes a Maximum Power Point Tracking (MPPT) unit 30. The MPPT unit 30 serves to extract a maximum available power from the photovoltaic cells in the solar panels 7, which depends upon a variety of conditions which are taken into consideration by software that is executed by the MPPT unit 30. The MPPT unit 30 is connected to the solar panels 7 via a number of isolators (31a, 3 lb, 32), which serve to isolate the solar panels 7 from the rest of the system. A number of cable trays (33, 34, 35) are mounted with electrical cables, which provide an electrical connection between the components of the power supply 100.

[0080] FIG. 4 illustrates direct current wiring of the power supply 100, showing the MTTP unit 30 connected to the solar panels 7 via the isolators (3 la, 3 lb), three Quattro devices (5a, 5b, 5c), a Lynx DB unit 41, and a DC control unit 42. All Quattro to Lynx cables are the same length, and not exceeding 5m, in order to prevent DC ripple, which occurs if DC cables are the wrong lengths, which would degrade the batteries. (Note that Quattro and Lynx are registered trade marks).

[0081] During use, the isolators (31a, 31b) receive electrical power from the solar panels 7, which is transferred to the MPPT unit 30. This electrical power is then transferred to the Lynx DB 41. The MPPT unit 30 is shown connected to the Lynx DB 41 by TriRated 10 mm Single Core cables. The electrical energy received from the solar panels 7 is stored in the battery pack 1 until it is to be used.

[0082] The inverters (5a, 5b, 5c) are configured to extract power from the backup generator in the event that the battery pack has become depleted. The Quattro inverters (5a, 5b, 5c) are shown connected to the Lynx DB 41 by TriRated 95 mm Single Core cables. The DC control unit 42 is shown connected to the Lynx DB 41 by 2 Core 1.5 mm cables. The power supply 100 is shown including three inverters: a Quattro master LI 5a, a Quattro follower L2 5b, and a Quattro follower L3 5c.

[0083] FIG. 5 illustrates further detail of the direct current wiring of the power supply 100, showing the PV string that connects the solar panels to the battery pack 1. The solar panels 7 are shown connected to the isolator 31 via 6mm PV1-F cables which are installed with a 40 A fuse 51. An array of 3 solar panels 7 is shown connected in series to the isolator 31, although the power supply 100 is not restricted to the number of solar panels 7 that may be installed. The isolator 31 serves to isolate the solar panels 7 from the rest of the system. The isolator is shown connected to the MPPT unit 30 via 6mm PV1-F cables, which receives a direct current of up to 150 volts. The MPPT unit 30 is connected to the Lynx DB unit 41, with the MPPT unit 30 providing an output direct current of 48 volts via 10mm Tri -Rated single core cables which are installed with a 60A fuse 52. From the Lynx DB unit 41, electrical energy can be transferred to the batteries 1.

[0084] The Lynx Distributor 41 serves as a DC Busbar. As illustrated by FIG. 5, the solar panels 7 are connected to the isolator 31 with one or more fuses 51, and the batteries 1 are connected to the Lynx Distributor 41 with one or more fuses 52. The Lynx Distributors 41 are connected to the 350A DC fuses which connect to the 350A DC isolators and then to the inverters 5 using 95mm DC electrical cables. The DC control unit 42 contains the components used to control the system along with the internet router, and the 48-12V DC-DC converter to supply 12V power to the control components.

[0085] FIG. 6 illustrates alternating current wiring of the power supply 100, showing a distribution board 60 and a contactor 61. The Quattro inverters (5a, 5b, 5c) are connected to an AC glycerine generator 2 configured to produce power at 36 kW. The cabin 8 includes a door 81 which can be used to access internal components of the power supply. Electrical cables arranged to transfer electrical power from the generator 2 to the inverters (5a, 5b, 5c), with FIG. 6 illustrating these electrical cables housed by cable trays which pass around the door frame. The distribution board 60 controls the distribution of electrical power from the inverters (5a, 5b, 5c) to the outlet 6. The electrical power is transferred via cables from the inverters (5a, 5b, 5c), to the contactor 61, to the distribution board 60, and to the outlet 6. The contactor 61 provides a way to stop the outgoing power: an emergency stop switch 62 can be used to stop power being transmitted via the distribution board 60 and power outlets 6. The outlets 6 can be customised for each power supply 100, with the example shown by FIG. 6 illustrating four outlets including three 32 Amp sockets, and one 125 Amp socket.

[0086] Electrical components are connected via the following cables:

[0087] • Generator to quattro - 3 x 25mm SY x 3.

[0088] • Quattro to contactor - 3 x 25mm SY x 3.

[0089] • Contactor to DB - 5 x 25mm SY x 1. • BD to SOC 4 - 5 x 25mm SY (i.e, a 125 Amp output socket, which serves as the main output to a distribution board: Commando socket).

[0090] • DB to SOC 1,2, 3 - 3 x 6mm SY (i.e., three 32 Amp output sockets, which serves to provide power to electrical tools directly from power supply: Commando socket).

[0091] • E / Stop - 3 x 1.5mm flex.

[0092] • Generator and contactor inlet wiring: all N and PE connected together.

[0093] • Note: from generator to contactor through the Quattro inverters, all AC cables are the same length.

[0094] FIG. 7 illustrates how electrical components of the power supply 100 are arranged, showing the 250A distribution board 60, the 185 A contactor 61, and the DC control unit 42.

[0095] FIG. 8 provides a flow chart illustrating a process for determining how electrical power S10 can be supplied by the power supply 100.

[0096] • Step Si l illustrates a normal operating mode of the power supply 100, during which electrical power is supplied using the battery pack 1. The batteries are charged using the solar panels 7, with this energy being drawn by the inverters 5 to provide electrical power via the outlet 6. If the demand on the battery pack 1 is higher than the supply, then eventually the battery pack 1 will become depleted, which results in a backup process (S2-S17) being implemented.

[0097] • Step S12 illustrates an assessment of whether the battery pack 1 has become depleted. The power supply 100 is periodically checked to assess whether the battery pack 1 can satisfy the demand of the system to provide electrical power. The power supply 100 continues to supply the electricity using the battery pack 1 until there is no longer a demand, or until it is determined that the battery pack 1 cannot satisfy the demand. Thus, if the battery pack 1 has not become depleted, then the battery pack 1 continues to supply the electrical power under the normal operation described in step Si l. However, if the battery pack 1 has become depleted, then the process progresses to step S13 and step SI 4, with a backup generator 2 taking over from the battery pack 1.

[0098] • Step S13 illustrates the generator 2 taking over from the battery pack 1 to supply the electrical power. Thus, if the battery pack 1 fails to satisfy the demand on the system, then electrical power is supplied using a backup generator 2. Dislosure is provided of a glycerine generator 2 serving as the backup generator. • Step S14 illustrates the backup generator 2 recharging the battery pack 1 using any surplus energy produced by the generator 2. Thus the batteries 1 are charged using any excess power that is produced by the backup generator, as well as the photovoltaics 7.

[0099] • Step S15 illustrates an assessment of whether the battery pack 1 has become recharged. If the battery pack 1 has become recharged, then it takes over from the generator 2. If the battery pack 1 has not become recharged, then the generator 2 continues to supply the electrical power. Thus, when the batteries become recharged, the backup generator 2 is turned off, and the system resumes normal operation, with the electrical power being supplied using the batteries 1.

[0100] • Step S16 illustrates an assessment of whether the demand for electrical power exceeds a threshold that can be supplied by the generator 2. The threshold corresponds to the maximum amount of electrical power that can be drawn from the generator. If this occurs, then this results in a deficit of electrical power that cannot be supplied by the generator 2. If the demand does not exceed the threshold that can be supplied by the generator 2, then steps S13-S15 continue until the battery pack 1 has become recharged and can resume supplying electrical power. However, if the threshold demand is exceeded, then the process progresses to step SI 7. Thus, even when in the backup mode, the power supply 100 continues to be periodically checked, to assess whether it can satisfy the demand of the system to provide electrical power, with mitigation being put in place in the event that a potential problem has been detected.

[0101] • Step S17 illustrates the deficit being supplied using the battery pack 1. The generator 2 continues to supply electrical power, with the maximum amount of power being transferred to the outlet 6. The deficit is satisfied by the battery pack 1, so that the load receives the electrical power from the outlet 6 of the power supply 100. The battery pack 1 will continue to supply the deficit S17 until the demand no longer exceeds the threshold SI 6, or until the battery pack 1 has once again become depleted.

[0102] Disclosure is provided of a way to mitigate a situation in which a backup generator 2 fails to satisfy the demand on the system. If this occurs, then electrical power is supplied using both the backup generator 2 and the batteries 1. In this situation, there will be no surplus power provided by the backup generator 2, and so the only recharging of the batteries 1 is from the photovoltaics 7. The batteries 1 supply the deficit electrical energy that is demanded by the system. When the demand reduces, such that it can be satisfied using the backup generator 2, then the batteries 1 stop supplying the deficit electrical energy, and the process returns to step S14. Thus, the backup generator 2 continues to supply the power and recharge the batteries 1, until the batteries 1 are determined in step SI 5 to have become fully charged. Once the batteries 1 are determined in step S15 to have become fully recharged, the process returns to step SI 1, which the power supply 100 operating in its normal mode.

[0103] The present disclosure outlines a glycerine backup generator 2 that is configured to recharge batteries 1 and provide a power assist under high load conditions. Glycerine is an example of a fuel that performs optimally when at a stable load, otherwise it doesn’t burn as effectively. However, the disclosure is not necessarily restricted to glycerine generators, and is applicable to any other types of generator which perform optimally when providing a stable load.

[0104] Power supplies 100 typically include inverters 5 that are configured to pull a load from the energy source, which is then converted into electricity and output from the power supply. If there is a demand for the inverters to pull a higher load from the system, then the generator 2 is put under a high stress, in order to increase the load. If consumer loads are higher than the inverters can provide, then the backup generator will be started, in order to power assist.

[0105] Disclosure is provided of a glycerine power source that serves as a fuel for the backup generator 2. When the power supply 100 is subject to a high demand for electrical power, then typically the inverters will be configured to pull more energy from their power source. However, for the present innovation, disclosure is provided of inverters 5 that have been configured so that they always draw a stable load from the generator 2. This ensures that the generator 2 always demands a consistent load when the backup generator 2 is switched on.

[0106] Using a normal hybrid system, if a power assist is to be provided, due to a change in the consumer load, then this will usually be accommodated by drawing more energy from the generator. However, this has been found to be problematic when burning glycerine, because glycerine generators perform optimally when providing a consistent load.

[0107] A problem addressed by the present innovation is how to satisfy the deficit in a situation for which the glycerine generator does not satisfy the demand for electrical power. Innovation is to be found in the way in which the deficit is accommodated by the batteries 1. The backup generator 2 will typically kick in when the batteries 1 are to be recharged. If the batteries 1 are depleted down, then they will be charged up by the backup generator 2. If the site loads get above a threshold level, then a power assist function is initiated.

[0108] The electrical energy is drawn from the batteries 1, through the inverter 5, and to an output voltage. If the batteries 1 become depleted, then the glycerine generator 2 serves as a backup, recharging the batteries and supplying the site.

[0109] The disclosed process is implemented by software that is executed by a processor that is typically on site forming part of the power supply 100. The processor may form part of the inverter 5 of the power supply 100. The inverters 5 may be installed with software configured to implement the disclosed method S10. The inverters 5 can be remotely updated, in order to function as expected. This ensures that the client can switch on the power supply and proceed with their work without having to be concerned with the load that is being placed on the power supply 100.

[0110] The disclosed examples can be realised by a computer of a system or apparatus. These examples can be implemented by any device configured to execute instructions, or any dedicated hardware that is capable of carrying out all or a portion of the functionality. Disclosure is provided of hardware (e.g., a processor such as a central processing unit (CPU) or a microprocessor unit (MPU)) configured to read out and executes a program recorded on a memory device to perform the functions of the disclosed examples. For this purpose, the program is provided to the computer for example via a network or from a recording medium of various types serving as the memory device (e.g., a computer-readable medium such as a non-transitory computer-readable medium). The steps of the disclosed methods may be performed in any suitable order, or simultaneously where possible.

[0111] Although the disclosed subject matter has been described using specific terminology relating to apparatus features and / or method features, it is to be understood that the claimed subject matter is not necessarily limited to the examples disclosed. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions. The advantages disclosed may relate to several of the examples that are disclosed.

Claims

Claims1. A power supply (100) comprising: a battery pack (1) configured to supply (SI 1) electrical power; a glycerine generator (2) configured to supply (SI 3) electrical power if the battery pack(1) has become depleted (S12), wherein the glycerine generator (2) is configured to recharge (S14) the battery pack (1); a determination unit (3) configured to determine (SI 6) whether a demand on the power supply (100) exceeds a threshold that can be supplied by the glycerine generator (2), resulting in a deficit of electrical power that cannot be supplied by the glycerine generator (2); and a control unit (4) configured to control (SI 7) the battery pack (1) to supply the deficit of electrical power that cannot be supplied by the glycerine generator (2).

2. The power supply (100) according to claim 1, wherein the control unit (4) is configured to control (SI 7) the battery pack to supply the deficit of electrical power that cannot be supplied by the glycerine generator (2) while the determination unit determines (SI 6) that the demand on the power supply (100) exceeds the threshold that can be supplied by the glycerine generator(2).

3. The power supply (100) according to claim 1 or claim 2, further comprising an inverter (5) configured to control operation of the battery pack (1) and the glycerine generator (2) based upon an instruction received from the control unit (4).

4. The power supply (100) according to any preceding claim, wherein the determination unit (3) is configured to determine (S15) whether the battery pack (1) has been recharged, and the control unit (4) is configured to control (SI 1) the battery pack (1) to resume supplying the electrical power if the battery pack (1) has been recharged.

5. The power supply (100) according to any preceding claim, wherein the power supply (100) is self-contained to include the battery pack (1), the glycerine generator (2), the determination unit (3), and the control unit (4).

6. The power supply (100) according to any preceding claim, wherein the glycerine generator (2) serves as a backup to a renewable energy source.

7. The power supply (100) according to any preceding claim, further comprising a solar panel (7) configured to provide electrical energy for recharging the battery pack (1).

8. The power supply (100) according to claim 7, wherein during use, the solar panel (7) is arranged at an angle to the horizontal.

9. The power supply (100) according to any preceding claim, further comprising a cabin (8) configured to house electrical components of the power supply (100).

10. The power supply (100) according to claim 9, wherein the cabin (8) has a sloped roof.

11. The power supply (100) according to claim 9 or claim 10, wherein the cabin (8) has a triangular cross section.

12. A method (S10) of controlling a power supply (100), the method comprising: supplying (SI 1) electrical power using a battery pack (1); supplying (S13) electrical power using a glycerine generator (2) if the battery pack (1) has become depleted (S12), and recharging (S14) the battery pack (1) using the glycerine generator (2);determining (SI 6) whether a demand on the power supply (100) exceeds a threshold that can be supplied by the glycerine generator (2), resulting in a deficit of electrical power that cannot be supplied by the glycerine generator (2); and controlling (S17) the battery pack (1) to supply the deficit of electrical power that cannot be supplied by the glycerine generator (2).

13. The method (S10) according to claim 12, further comprising determining (SI 6) that the demand on the power supply (100) no longer exceeds the threshold that can be supplied by the glycerine generator (2); and controlling (SI 7) the battery pack (1) to stop supplying the electrical power if the demand on the power supply (100) no longer exceeds the threshold.

14. The method (S10) according to claim 12 or claim 13, further comprising determining (SI 5) whether the battery pack (1) has been recharged; and controlling (Si l) the battery pack (1) to resume supplying the electrical power if the battery pack (1) has been recharged.

15. A program which, when executed, causes the power supply (100) to perform a method (S10) according to any one of claims 12 to 14.

16. A computer-readable storage medium storing a program according to claim 15.

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