A vehicle comprising a hydrogen combustion range extender and a method of controlling a vehicle

Abstract

A vehicle comprising a hydrogen combustion range extender for a vehicle and a method of controlling a vehicle comprising a hydrogen combustion range extender. The hydrogen combustion range extender comprising: a fixed-speed piston combustion engine, arranged to target a single RPM speed whilst combusting, wherein the single RPM speed is the peak efficiency engine speed of the fixed-speed piston combustion engine; an E-machine inverter connected to the crankshaft of the fixed-speed piston combustion engine; the E-machine inverter arranged to operate in an electric motor mode to target rotating the crankshaft of the fixed-speed piston combustion engine at the single RPM speed, whilst the piston combustion engine is not combusting; wherein after the E-machine inverter has rotated the crankshaft to the single RPM speed, or within a predetermined tolerance of the single RPM speed, the hydrogen combustion range extender is arranged to inject hydrogen into the piston combustion engine to begin combustion; wherein the hydrogen combustion range extender is arranged to target combustion of hydrogen to rotate the crankshaft at the single RPM speed; wherein the E-machine inverter is arranged to operate in an electric generator mode whilst the piston combustion engine is combusting hydrogen.

Description

[0001] This invention relates to a vehicle comprising a hydrogen combustion range extender and a method of controlling a vehicle. In particular it relates to a hydrogen combustion range extender which has a fixed-speed piston combustion engine and e-machine inverter. BACKGROUND

[0002] Pure combustion engines have been banned in the UK from 2035 and most of Europe from 203012035. However no such action has been taken in the third world or in developing countries / continents such as Africa, India and South America and the ban in Europe excludes alternate fuel range extenders and hybrids in some applications. Developing countries cannot employ battery electric vehicles (BEVs) as there is not an electricity grid capable of supporting charging, and fuel cells are also far too expensive to employ now or in the near future in these countries. BRIEF SUMMARY OF THE DISCLOSURE

[0003] Aspects and embodiments of the invention provide a vehicle comprising a hydrogen combustion range extender, and a method of controlling a vehicle.

[0004] In accordance with the present disclosure, there is provided a vehicle comprising a hydrogen combustion range extender, the hydrogen combustion range extender comprising: a fixed-speed piston combustion engine, arranged to target a single RPM speed whilst combusting, wherein the single RPM speed is the peak efficiency engine speed of the fixed-speed piston combustion engine; an E-machine inverter connected to the crankshaft of the fixed-speed piston combustion engine; the E-machine inverter arranged to operate in an electric motor mode to target rotating the crankshaft of the fixed-speed piston combustion engine at the single RPM speed, whilst the piston combustion engine is not combusting; wherein after the E-machine inverter has rotated the crankshaft to the single RPM speed, or within a predetermined tolerance of the single RPM speed, the hydrogen combustion range extender is arranged to inject hydrogen into the piston combustion engine to begin combustion; wherein the hydrogen combustion range extender is arranged to target combustion of hydrogen to rotate the crankshaft at the single RPM speed; wherein the E-machine inverter is arranged to operate in an electric generator mode whilst the piston combustion engine is combusting hydrogen.

[0005] In some examples, the fixed-speed piston combustion engine is a port injection engine.

[0006] In some examples, the vehicle comprises a high voltage bus.

[0007] In some examples, the vehicle is arranged to heat the fixed-speed piston combustion engine using a thermal device powered by the high voltage bus.

[0008] In some examples, the vehicle comprises a thermal management system, wherein the thermal management system is arranged to heat the fixed-speed piston combustion engine using waste heat put into the thermal management system.

[0009] In some examples, the vehicle comprises an electrically heated catalyst device and a selective catalytic reduction device.

[0010] In some examples, the electrically heated catalyst is heated using power from the high voltage bus, and wherein the vehicle is arranged to control the temperature of the selective catalytic reduction device using heat from the electrically heated catalyst device.

[0011] In some examples, the vehicle comprises an electric propulsion system, wherein the electric propulsion system comprises: a traction electric motor; a traction inverter; an electric energy store; wherein the traction electric motor is arranged to provide traction to drive one or more wheels of the vehicle; wherein the traction inverter is connected to the traction electric motor; wherein the hydrogen combustion range extender is arranged to provide electrical power to the electric propulsion system when the e-machine inverter is operating in the electric generator mode, and is arranged to receive electrical power from the electric propulsion system when the e-machine inverter is operating in the electric motor mode.

[0012] In some examples, the vehicle comprises a pressure vessel for storing hydrogen.

[0013] In some examples, the single RPM speed is 5000 RPM.

[0014] In some examples, the vehicle is any one of: an automotive vehicle, a watercraft, an aircraft.

[0015] In accordance with the present disclosure, there is provided a method of controlling a vehicle, the vehicle comprising a hydrogen combustion range extender; wherein the hydrogen combustion range extender comprises: a fixed-speed piston combustion engine; an E-machine inverter; wherein the fixed-speed piston combustion engine is arranged to target a single RPM speed whilst combusting, wherein the single RPM speed is the peak efficiency engine speed of the fixed-speed piston combustion engine; wherein the E-machine inverter is connected to the crankshaft of the fixed-speed piston combustion engine; wherein the method comprises: operating the E-machine inverter in an electric motor mode to target rotating the crankshaft of a fixed-speed piston combustion engine at the single RPM speed, whilst the piston combustion engine is not combusting; combusting hydrogen by injecting hydrogen into the piston combustion engine after the E-machine inverter has rotated the crankshaft to the single RPM speed, or within a predetermined tolerance of the single RPM speed; targeting combustion of hydrogen to rotate the crankshaft at the single RPM speed; operating the E-machine inverter in an electric generator mode whilst the piston combustion engine is combusting hydrogen.

[0016] In some examples, the method comprises heating the fixed-speed combustion engine using a thermal management system of the vehicle prior to the combusting of hydrogen in the fixed-speed combustion engine.

[0017] In some examples, the method comprises determining, by the vehicle, that the hydrogen combustion range extender is to be activated to combust hydrogen before allowing the operating of the e-machine inverter in the electric motor mode to target rotating the crankshaft of a fixed-speed piston combustion engine hydrogen.

[0018] In some examples, a state of charge of an electric energy store of the vehicle being below a first state of charge threshold is used to determine that the hydrogen combustion range extender is to be activated to combust hydrogen.

[0019] In some examples, an operation mode of a high voltage power management module of the vehicle is used to determine that the hydrogen combustion range extender is to be activated to combust hydrogen.

[0020] In some examples, the method comprises, prior to operating the e-machine inverter in the electric motor mode to target rotating the crankshaft of a fixed-speed piston combustion engine at the single RPM speed, heating an electrically heated catalyst of the vehicle using power from a high voltage bus of the vehicle, and controlling the temperature of a selective catalytic reduction device of the vehicle using heat from the electrically heated catalyst device.

[0021] In some examples, the method comprises confirming, by the vehicle, that the temperature of the selective catalytic reduction device is being controlled using the heat from the electrically heated catalyst device before allowing the operating of the e-machine inverter in an electric motor mode to target rotating the crankshaft of a fixed-speed piston combustion engine at the single RPM speed.

[0022] In some examples, the method comprises confirming that the fixed-speed piston combustion engine has been heated to or is at a minimum temperature before allowing the operating of the E-machine inverter in an electric motor mode to target rotating the crankshaft of the fixed-speed piston combustion engine.

[0023] In some examples, the method comprises opening valves on a pressure vessel of the vehicle to allow the injecting of the hydrogen into the piston combustion engine to begin the combusting after the E-machine inverter has rotated the crankshaft to the single RPM speed, wherein coils of the fixed-speed combustion engine are activated to enable the combusting of hydrogen.

[0024] In some examples, the method comprises confirming stable combustion using lambda feedback after the combusting of hydrogen has begun.

[0025] In some examples, the method comprises confirming stable combustion by monitoring the output voltage of the E-machine inverter after the combusting of hydrogen has begun.

[0026] In some examples, the method comprises stopping heating of electrically heated catalyst following confirmation of stable combustion.

[0027] In some examples, the method comprises activating Urea / AdBlue management in the selective catalytic reduction device after stopping heating of the electrically heated catalyst.

[0028] In some examples, the method comprises stopping the combusting of hydrogen based on the state of charge of the electric energy store being above a second state of charge threshold, or stopping combustion of hydrogen based on the operation mode of the high voltage power management module.

[0029] In accordance with the present disclosure, there is provided a controller which comprises one or more processors, one or more memory, wherein the one or more memory stores computer program instructions. The computer program instructions, when executed by the one or more processors, causes the controller to perform any of the methods of the preceding paragraphs.

[0030] In accordance with the present disclosure, there is provided a hydrogen combustion generator, the hydrogen combustion generator comprising: a fixed-speed piston combustion engine, arranged to target a single RPM speed whilst combusting, wherein the single RPM speed is the peak efficiency engine speed of the fixed-speed piston combustion engine; an E-machine inverter connected to the crankshaft of the fixed-speed piston combustion engine; the E-machine inverter arranged to operate in an electric motor mode to target rotating the crankshaft of the fixed-speed piston combustion engine at the single RPM speed, whilst the piston combustion engine is not combusting; wherein after the E-machine inverter has rotated the crankshaft to the single RPM speed, or within a predetermined tolerance of the single RPM speed, the hydrogen combustion range extender is arranged to inject hydrogen into the piston combustion engine to begin combustion; wherein the hydrogen combustion generator is arranged to target combustion of hydrogen to rotate the crankshaft at the single RPM speed; wherein the E-machine inverter is arranged to operate in an electric generator mode whilst the piston combustion engine is combusting hydrogen.

[0031] The hydrogen combustion generator can comprise any of the features of the hydrogen combustion range extender described herein.

[0032] In accordance with the present disclosure, there is provided a hydrogen combustion range extender for a vehicle, the hydrogen combustion range extender comprising: a fixed-speed piston combustion engine, arranged to target a single RPM speed whilst combusting, wherein the single RPM speed is the peak efficiency engine speed of the fixed-speed piston combustion engine; an E-machine inverter connected to the crankshaft of the fixed-speed piston combustion engine; the E-machine inverter arranged to operate in an electric motor mode to target rotating the crankshaft of the fixed-speed piston combustion engine at the single RPM speed, whilst the piston combustion engine is not combusting; wherein after the E-machine inverter has rotated the crankshaft to the single RPM speed, or within a predetermined tolerance of the single RPM speed, the hydrogen combustion range extender is arranged to inject hydrogen into the piston combustion engine to begin combustion; wherein the hydrogen combustion range extender is arranged to target combustion of hydrogen to rotate the crankshaft at the single RPM speed; wherein the E-machine inverter is arranged to operate in an electric generator mode whilst the piston combustion engine is combusting hydrogen. The hydrogen combustion range extender for a vehicle described in this paragraph can comprise any of the features of the hydrogen combustion range extenders described herein. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Embodiments of the invention are further described hereinafter with reference to the accompanying drawings, in which: Figure 1 shows a vehicle according to examples disclosed herein; Figure 2 shows a hydrogen combustion range extender according to examples disclosed herein; Figure 3 shows a fixed-speed combustion engine according to examples disclosed herein; Figure 4 shows a fixed speed combustion engine according to examples disclosed herein; Figure 5A shows a schematic of various systems and components of a vehicle according to examples disclosed herein; Figure 5B shows a schematic of a part of a vehicle according to examples disclosed herein; Figure 6 shows a schematic of a part of a vehicle according to examples disclosed herein; Figure 7 shows a method of controlling a vehicle according to examples disclosed herein; Figure 8 shows a method of controlling a vehicle according to examples disclosed herein; Figure 9 shows a method of controlling a vehicle according to examples disclosed herein; and Figure 10 shows a schematic of a controller of a vehicle according to examples disclosed herein. DETAILED DESCRIPTION

[0034] Battery electric vehicles (BEVs) have seen a surge in popularity and development due to the increasing need to provide zero emission transport, as the world looks to achieve its net zero emission targets. However BEVs are not feasible for widespread adoption in developing countries which will lack an electricity grid capable of supporting charging for fleets of BEVs for the foreseeable future.

[0035] There is local knowledge and manufacturing capability of combustion engines in developing countries, but combustion engines need to change significantly to deliver wide scale, cost effective emissions reduction. It was realised during the devising of this invention that this can be achieved by employing a step change in design and implementation of a piston combustion engine coupled with the use of Hydrogen as a fuel for combustion.

[0036] Traditional piston combustion engines can be converted or designed to run on Hydrogen as the fuel but this has typically involved the use of direct injection of hydrogen gas into the combustion chamber and advanced ignition systems (such as plasma jet) which adds high cost and high complexity.

[0037] During the devising of this invention, it was realised that port injection with Hydrogen is possible, which has benefits in terms of simplifying the manufacture of the combustion engine and reducing cost, but necessitates a different approach to the role of the combustion engine in a transport or power generation application due to the limitations of port injection.

[0038] It was also realised that the smaller the engine the more suitable it is for port injection and that port injection is most suitable for medium RPM applications due to the ever decreasing injection window as RPM increases. Smaller capacity, low cylinder count engines with minimal frictional losses are the perfect candidate for conversion to hydrogen fuel as the small cylinder swept volume, good valve area, injector location and strong internals lend themselves to a hydrogen port injection application.

[0039] The use of port injection is important as it significantly reduces cost over other options whilst creating a simpler and easier to manufacture engine package. Cost benefits are also realised upstream as the hydrogen delivery pressure is lower, allowing reduced costs on pipe work and greater utilisation of hydrogen stored in the pressure vessel due to a lower minimum pressure than is possible with direct injection.

[0040] Directly coupling a suitable e-machine inverter to a port injection hydrogen combustion engine produces a lightweight, efficient power generator suitable for use as a range extender or static power generator. This combination can be leveraged to create very low to zero emissions passenger cars, light commercial vehicles and power generators for land and marine use.

[0041] Combustion engines are most efficient at medium RPM where the power produced is not significantly impacted by high RPM pumping and frictional losses. Port injection of hydrogen is also most suitable for medium RPM use. It was realised during the devising of this invention that a significant advantage can be realised by creating an operating regime where the engine is never run at low RPM or high RPM but rather only in a narrow, well optimised window. In particular, the engine can be run at peak efficiency engine speed of the engine, or within an accepted tolerance of the peak efficiency engine speed.

[0042] This narrow operating window can be realised by using the e-machine inverter as a motor / generator unit. In an electric mode of operation the e-machine inverter will motor the piston combustion engine to the required RPM before any combustion takes place in the piston combustion engine.

[0043] In addition this approach removes the requirement for the engine to deal with transients allowing it to be completely optimised for a single speed of operation which provides significant opportunity to reduce emissions, fuel burn rate and NVH (noise, vibration and harshness) versus an engine that must be capable of operating in transient conditions.

[0044] Figure 1 shows a vehicle 100 according to examples disclosed herein. The vehicle 100 comprises a hydrogen combustion range extender 110. Figure 2 shows a hydrogen combustion range extender 110 according to examples disclosed herein. It is to be understood that the hydrogen combustion range extender 110 is only used as a range extender in the vehicle shown in Figure 1, in that it does not directly provide traction to the wheels of the vehicle 100. Instead the hydrogen combustion range extender 110 is arranged to generate electricity through the combustion of hydrogen, with the electricity then being provided for use by the propulsion system of the vehicle 100.

[0045] As shown in Figure 2, the hydrogen combustion range extender 110 comprises a fixed-speed piston combustion engine 112, which is arranged to target a single RPM speed whilst combusting. The single RPM speed is the peak efficiency engine speed of the fixed-speed piston combustion engine 112. The peak efficiency engine speed of an engine can be determined via dynamometer testing or similar to determine the maximum available torque for the minimum amount of fuel, i.e. where the engines losses (pumping, frictional etc.) are least versus the amount of power produced for the fuel consumed.

[0046] The hydrogen combustion range extender 110 also comprises an e-machine inverter 114 connected to the crankshaft 116 of the fixed-speed piston combustion engine 112.

[0047] The e-machine inverter 114 is arranged to operate in an electric motor mode to target rotating the crankshaft 116 of the fixed-speed piston combustion engine 112 at the single RPM speed, whilst the piston combustion engine 112 is not combusting. According to examples disclosed herein, whilst the fixed-speed piston combustion engine 112 is not combusting, hydrogen is not injected into the combustion engine 112. Coils and injectors of the engine 112 are not activated whilst the fixed-speed combustion engine 112 is not combusting.

[0048] After the e-machine inverter 114 has rotated the crankshaft to the single RPM speed, or within a predetermined tolerance of the single RPM speed, the hydrogen combustion range extender 110 is arranged to combust hydrogen by injecting hydrogen into the piston combustion engine 112.

[0049] Once the fixed-speed piston combustion engine 112 has begun combusting, the hydrogen combustion range extender 110 is arranged to target combustion of hydrogen to rotate the crankshaft 116 at the single RPM speed.

[0050] Whilst the piston combustion engine 112 is combusting hydrogen, the e-machine inverter 114 is arranged to operate in an electric generator mode. The hydrogen combustion range extender 110 according to examples disclosed herein provides a means of generating electricity by combusting hydrogen using a piston combustion engine 112 which has a simplified and streamlined design which reduces the complexity of manufacture and maintenance as well as reducing cost.

[0051] According to examples disclosed herein, the fixed-speed piston combustion engine 112 is a port injection engine. This reduces the complexity of the design, and therefore reduces the cost. For example injectors do not need to withstand as higher pressures compared to direct injection, and the delivery pressure of the hydrogen can be lower compared to direct injection.

[0052] Figure 3 shows a fixed-speed combustion engine 112 according to examples disclosed herein. According to examples disclosed herein, the vehicle 100 comprises a high voltage bus. For example the vehicle 100 may comprise an electric propulsion system which uses a high voltage bus. The hydrogen range extender 110 and other associated parts / systems of the vehicle according to examples disclosed herein uses the high voltage bus to further optimise the integration of the hydrogen range extender 110 into a vehicle 100 which comprises an electrical propulsion system.

[0053] In particular, according to examples disclosed herein, the vehicle 100 is arranged to heat the fixed-speed piston combustion engine 112 using a thermal device 300 powered by the high voltage bus, as shown in Figure 3. For example, the thermal device 300 can comprise a coil heater or other heater, which can be arranged to heat the fixed-speed piston combustion engine 112 by passing coolant of the fixed-speed piston combustion engine 112 to the thermal device 300 to heat up the fixed-speed piston combustion engine 112. As the fixed-speed piston combustion engine 112 is designed to run at a single RPM speed, it is beneficial to ensure that the combustion engine 112 is at optimal temperature before it is required to combust to generate electricity. As the combustion engine 112 may be required to operate in short bursts to provide the necessary electrical generation, ensuring that the combustion engine 112 is at an efficient operating temperature before combustion occurs ensures that the hydrogen range extender 110 provides the optimum amount of electrical energy generation. According to examples, heating the combustion engine 112 using the thermal device avoids a cold start. According to examples, a starting temperature of 20 degrees above ambient temperature (temperature of the atmosphere the engine 112 is operating in) removes the majority of the cold start penalties.

[0054] As illustrated in Figure 3, the fixed speed combustion engine 112 can comprise injectors 1121 for injecting hydrogen into the combustion chamber(s). The fixed speed piston combustion engine 112 also comprises one or more coils 1122 which produce the spark for igniting the hydrogen injected into the combustion chamber(s). The fixed speed piston combustion engine 112 also comprises a cylinder assembly 1123, which comprises the combustion chamber(s), cylinder(s) and piston(s). Crankshaft 116 is not shown in Figure 3 for simplicity but it is to be understood that it is connected to the output of the piston(s) of the cylinder assembly 1123.

[0055] According to examples disclosed herein, as the fixed-speed piston combustion engine 112 only operates at a single RPM speed, the combustion engine 112 can be built without a throttle, which provides a benefit of simplifying construction and reducing cost. The engine 112 can maintain itself at the single RPM speed by controlling the air / fuel mixture and the load the e-machine inverter 114 places on the engine 112. The air / fuel mixture can be controlled by varying the opening of the injectors 1121.

[0056] Figure 4 shows a fixed-speed combustion engine 112 according to examples disclosed herein. According to examples disclosed herein, the vehicle 100 comprises a thermal management system 400. The thermal management system 400 is arranged to heat the fixed-speed piston combustion engine 112 using waste heat put into the thermal management system 400. The thermal management system 400 may be used in conjunction with the thermal device 300, or may be used as an alternative to the thermal device 300 to heat the fixed speed piston combustion engine 112.

[0057] As described above, it’s beneficial for the fixed speed piston combustion engine 112 to be kept at an appropriate operating temperature before it is required to begin combustion to generate electricity, to avoid cold start penalties. Therefore the thermal management system 400 of the vehicle 100 can be used to manage the temperature of the fixed-speed piston combustion engine 112. According to examples disclosed herein, the vehicle 100 can comprise an electric propulsion system. This can include one or more traction motors, traction inverters and electrical energy stores as described herein. Each of these produce heat which needs to be managed to prevent these components from overheating and also to keep them at an optimal operating window. Therefore the waste heat from the electric propulsion system can be used to heat and maintain the fixed-speed piston combustion engine 112 at an appropriate temperature for optimal combustion when it is called upon to generate electricity.

[0058] Figure 4 shows part of the thermal management system 400. In particular it shows two pipes connected to the fixed-speed piston combustion engine 112, with a dotted line representing that these pipes are connected to other components which are part of and connected to the thermal management system 400. As an example, one of the pipes may bring incoming coolant into the fixed-speed piston combustion engine 112, and the other of pipes may take coolant away from the fixed-speed piston combustion engine 112. The pipes may be directly connected to another component of the vehicle 100 which produces heat, for example a traction electric motor, a traction inverter, an electric energy store. In some examples the pipes are connected to other components of the thermal management system 400, such as pumps or coolant reservoirs which are themselves connected to other components of the thermal management system 400 or parts of the vehicle which use the thermal management system 400.

[0059] Figure 5A shows a schematic of various systems and components of a vehicle 100 according to examples disclosed herein, and how they interact.

[0060] As shown in the top left of Figure 5A, according to examples disclosed herein, the vehicle 100 comprises an electrically heated catalyst device 512 and a selective catalytic reduction device 514. As shown in Figure 5A, the electrically heated catalyst (EHC) device 512 and the selective catalytic reduction (SCR) device 514 form part of a catalytic system 510.

[0061] Although the hydrogen combustion range extender 110 does not combust hydrocarbons, it will still produce nitrous oxide which needs to be removed from the exhaust gases of the fixed-speed piston combustion engine 112 to meet emissions regulations. The electrically heated catalyst device 512 and the selective catalytic reduction device 514 are therefore provided to remove nitrous oxide from the exhaust gases to the necessary levels required. As shown in Figure 5A, ambient air enters the fixed speed piston combustion engine 112 as illustrated by arrow 580 and exhaust gas from the combustion of hydrogen exits the fixed-speed piston combustion engine 112 as illustrated by arrow 581. The exhaust gas enters the catalytic system 510 and passes through the electrically heated catalyst device 512 and the selective catalytic reduction device 514. The electrically heated catalyst device 512 is used as a pre-heater to bring the selective catalytic device 514 up to an appropriate operating temperature. Exhaust air which has been treated by the catalytic system 510 is illustrated by arrow 583.

[0062] According to examples disclosed herein, the electrically heated catalyst 512 is heated using power from the high voltage bus. Power is provided to the electrically heated catalyst 512 by the high voltage bus via a first power distribution unit 530 of the vehicle 100, which is shown in Figure 5A. Arrow 582 illustrates the electrical power being provided to the catalytic system 510. The vehicle is arranged to control the temperature of the selective catalytic reduction device 514 using heat from the electrically heated catalyst device 512.

[0063] The catalytic system 510 can also comprise Urea / Adblue injectors, which inject Urea / Adblue upstream of the selective catalytic reduction device 514. The Urea / Adblue, or another reductant such as ammonia, aqueous ammonia, reacts with the nitrous oxide over the catalyst in the selective catalytic reduction device 514 and converts the nitrous oxide into harmless compounds such as diatomic nitrogen and water.

[0064] As described herein, according to examples the vehicle 100 comprises a first power distribution unit 530 for the hydrogen combustion range extender 110 and the catalytic system 510. The first power distribution unit 530 is arranged to control the demand required from the hydrogen combustion range extender 110 and also provide power to the hydrogen combustion range extender 110 when the e-machine inverter 114 is operating in the electric motor mode. This two-way electrical provision between the first power distribution unit 530 and the hydrogen combustion range extender 110 is illustrated by arrow 584. As described above the first power distribution unit 530 also controls the electrical power provided to the catalytic system 510 from the high voltage bus. The hydrogen combustion range extender 110 is also powered by the high voltage bus.

[0065] According to examples disclosed herein and as shown in Figure 5A, the vehicle 100 comprises a pressure vessel 520 for storing hydrogen. The pressure vessel 520 comprises valves to control the flow of hydrogen to the hydrogen combustion range extender 110, with the flow being represented by arrow 585. As described above, injectors of the fixed-speed piston combustion engine 112 are used to inject hydrogen into the combustion chamber(s).

[0066] According to examples disclosed herein, the vehicle comprises an electric propulsion system 500, as represented in Figure 5A by the dashed box. It is to be understood that the components included within the electric propulsion system 500 in Figure 5A is not the only possible arrangement and other components of the vehicle 100 may be included within the electric propulsion system 500, and equally some of the components shown as being part of the electric propulsion system 500 in Figure 5A may not be part of the system 500 in other examples. For example the vehicle control unit 540 in some examples may form part of the electric propulsion system 500.

[0067] According to examples and as shown in Figure 5A, the electric propulsion system 500 comprises: a traction electric motor 504; a traction inverter 502; an electric energy store 506. The traction electric motor 504 is arranged to provide traction to drive one or more wheels of the vehicle 100. The traction inverter 502 is connected to the traction electric motor 504.lt is to be understood that the vehicle 100 can comprise more than one traction electric motor 504 for providing traction to the wheels, and can also comprise more than one traction inverter 502 and more than one electric energy store 506.

[0068] The hydrogen combustion range extender 110 is arranged to provide electrical power to the electric propulsion system 500 when the e-machine inverter 114 is operating in the electric generator mode, and is arranged to receive electrical power from the electric propulsion system 500 when the e-machine inverter 114 is operating in the electric motor mode.

[0069] In the example of Figure 5A, the vehicle 100 comprises a vehicle power distribution 550, which is arranged to distribute power between the hydrogen combustion range extender 110, the catalytic system 510 and the electric propulsion system 500. It is to be understood that the vehicle power distribution 550 shown in Figure 5A may be a functional representation of the interaction between different components, or may be a module / unit in itself. In some examples, the first power distribution unit 530 and the vehicle power distribution 550 are part of one module / unit.

[0070] As shown by arrow 586, the vehicle power distribution 550 can receive power from the first power distribution unit 530, when the e-machine inverter 114 is operating in the electric generator mode. Conversely as shown by arrow 586 being two-way arrow, the vehicle power distribution 550 can provide power to the first power distribution unit 530, which can provide power to the hydrogen combustion range extender 110 when the e-machine inverter 114 is operating in the electric motor mode and can provide power to the catalytic system 510 to heat the electrically heated catalytic device 512.

[0071] As shown by arrow 587, the vehicle power distribution 550 can provide electrical power to the traction inverter 502 of the electric propulsion system 500, which can then be used to provide power to the traction motor 504 to drive one or more wheels of the vehicle. Conversely as shown by the arrow 587 being a two-way arrow, the vehicle power distribution 550 can receive power from the traction inverter 502, for example when the traction inverter 502 is operating in a generator mode which can be for example in situations where the electric propulsion system 500 is in a regenerative braking mode. The two way provision of power between the traction inverter 502 and the traction motor 504 is illustrated using arrow 591.

[0072] As shown in Figure 5A, according to examples disclosed herein the vehicle 100 also comprises a electric energy store management module 508, which in the example shown in Figure 5A is part of the electric propulsion system 500. The electric energy store management module 508 comprises a management system (which can be a battery management system in examples where the electric energy stores comprises a battery pack), contactors, a disconnect from the high voltage bus and the main fuse. The main function of the electric energy store management module 508 is to control the flow of voltage to and from the electric energy store 506 (as illustrated by two-way arrow 589) and the state of charge of the electric energy store 506.

[0073] As shown by two-way arrow 588, the electric energy store management module 508 can receive power from the vehicle power distribution 550 and conversely can provide power to the vehicle power distribution 550.

[0074] According to examples, the vehicle power distribution 550 can be a physical unit. For example the vehicle power distribution 550 can comprise a high voltage power management module. Figure 5B shows a schematic of an example high-voltage power management module, also known as a vehicle power distribution unit 550. The high-voltage power management module 550 shown in Figure 5B comprises a traction inverter interface subsystem 551 for exchanging DC power with the traction inverter 502 (illustrated by arrow 587). The module 550 also comprises a storage interface subsystem 552 to exchange DC power with the electric energy store 506 (illustrated by arrow 588) for providing power to drive the vehicle 100, which may be via electric energy store management module 508 as shown in Figure 5.

[0075] The high-voltage power management module 550 also comprises a hydrogen combustion range extender subsystem 553 for receiving DC power from the hydrogen combustion range extender 110 (illustrated by arrow 586), which may be via the first power distribution unit 530, and configured to drive the one or more motors 504 through the traction inverter interface subsystem 551 of the high voltage power management module 550.

[0076] The high-voltage power management module 550 also comprises a switching module 554 configured to direct the voltage between the DC power of the storage interface subsystem 552, the hydrogen combustion range extender interface subsystem 553 and the traction inverter interface subsystem 551, wherein the switching module is configured to be operable to switch between (including rapidly switching) or simultaneously combine DC power from the storage interface subsystem 552 and the hydrogen combustion range extender interface subsystem 553 to provide DC power to the inverter interface subsystem 551 to drive the one or more motors for driving the vehicle 100.

[0077] Power management module 550 also comprises control circuitry 555 coupled to the switching module 554 to control the switching module 554 to select or combine a source of DC power from the electric energy store 506 and the hydrogen combustion range extender 110 to provide DC power to the traction inverter interface subsystem 551.

[0078] Although not shown in the Figures, the control circuitry 555 may communicate with a vehicle control unit, such as vehicle control unit 540 shown in Figure 5A to receive its input, including necessary to torque demands from the vehicle 100. The control circuitry 555 may also be connected to and control the traction inverter interface subsystem 551, the electric energy store interface subsystem 552 and the hydrogen combustion range extender interface subsystem 553.

[0079] Other control unit architectures for the vehicle power distribution module / unit 550 are envisaged.

[0080] Turning back to Figure 5A, The electric energy store 506 can comprise any suitable energy store for a vehicle 100. For example it can comprise a battery pack, such as a 400 V battery pack, or it can include other energy stores, such as supercapacitors. As shown in Figure 5A, the electric energy store 506 provides power to a low-voltage electric energy store 560. The low-voltage electric energy store 516 of the vehicle 100 can comprise a 12 / 24V battery and DC / DC converter. Such batteries are typical in automotive vehicles 100 and are used to power infotainment systems, lighting of the vehicle and other systems of the vehicle 100. Arrow 590 illustrates the provision of electrical power from the electric energy store 506 to the low-voltage electric energy store 516.

[0081] As shown in Figure 5A, according to examples disclosed herein the vehicle 100 comprises a control unit 540, also known as a vehicle control unit. The control unit 540 comprises one or more processes and memory. The memory stores computer program instructions, which when executed by the one or more processes controls the vehicle 100 according to methods described herein. The control unit 540 is arranged to control the electric propulsion system 500 to provide the necessary torque demands, regenerative braking demands and to control the flow of charge to and from the electric energy store 506 as well as controlling its state of charge.

[0082] The control unit 540 also controls the use of the hydrogen combustion range extender 110. In particular the control unit 540 controls when the hydrogen combustion range extender 100 is to be turned on to divert electrical power to cause the e-machine inverter 114 to operate in motor mode to rotate the crankshaft 116 of the combustion engine 112 up to the single RPM speed and also controls the start of the combustion of the hydrogen in the range extender 110 and the switching of the e-machine inverter 114 to operate in the generator mode.

[0083] The control unit 540 also controls the catalytic system 510 to work in conjunction with the hydrogen combustion range extender 110. In particular the vehicle control unit 540 is arranged control when the electrically heated catalyst 512 is activated and also the injection of Urea / Adblue or other reductant for reaction with nitrous oxide over the catalyst of the selective catalytic reduction device 514.

[0084] The communication between the control unit 540, the first power distribution unit 530, the hydrogen combustion range extender 110, the pressure vessel 520 and the catalytic system 510 are illustrated by the double ended line arrows between these components, and according to examples disclosed herein this is referred to as the hydrogen combustion range extender communications bus.

[0085] As shown in Figure 5A and according to examples disclosed herein, the control unit 540 communicates with a first communications node 503, which manages the communication between the traction motor 504, the traction inverter 502 and the control unit 540.

[0086] The control unit 540 is arranged to control the traction motor 504 and the traction inverter 502 to provide the necessary torque output to drive one or more wheels using torque command signals generated by the control unit 540 and / or received by the control unit 540. The control unit 540 also controls the traction motor 504 and the traction inverter 502 to operate in different modes of operation. For example in one mode of operation, the traction inverter 502 may draw power from the vehicle power distribution 550, and use the power to cause the one or more motors 504 to drive wheels of the vehicle 100.

[0087] In another mode of operation, the traction inverter 502 operates in a generator mode and uses the rotation of the motor 504 due to the motion of the one or more wheels to generate electricity and to cause regenerative braking which provides electrical power to the vehicle power distribution 550. Other modes of operation are possible. The double ended line arrows between the vehicle control unit 540, the first communications node 503, the traction motor 504 and the traction inverter 502 according to examples is referred to as the traction system communications bus.

[0088] As shown in Figure 5A according to examples disclosed herein, the control unit 540 communicates with electric energy store management module 508 and the electric energy store 506 via second communications node 570. Control unit 540 is arranged to control the electric energy store management module 508 to cause discharging and charging of the electric energy store 506 as required and to monitor the state of charge of the electric energy store 506 as well as its temperature and other parameters. The double ended line arrows between the control unit 540, the second communications node 570, the electric energy store management module 508 and the electric energy store 506 illustrate the communication pathways between these components and according to examples is referred to as the high-voltage communications bus.

[0089] It’s to be understood that the vehicle control unit 540 can be connected to other controllers or units of the vehicle 100 which are not described herein for simplicity. For example the control unit 540 can also control the braking system of the vehicle 100, steering system, thermal management system (as described herein in relation to Figure 4 and other examples).

[0090] The vehicle 100 as shown in Figure 5A and according to examples disclosed herein therefore provides a zero emissions vehicle 100 which is beneficially less reliant on charging infrastructure, which is particularly beneficial for developing countries which lack charging infrastructure and will do for the stable future. The vehicle 100 can operate as a typical electrical vehicle (such as a battery electric vehicle) in some modes of operation, where the electric energy store 506 provides power to the traction inverter 502 to cause the traction motor 504 (or traction motors 504) to drive one or more wheels of the vehicle and can also cause regenerative braking from the traction motor 504 rotating using the rotation of the one or more wheels to generate electricity using the traction inverter 502.

[0091] Beneficially, when required by modes of operation of the control unit 514, the hydrogen range extender 100 can be used to power the one or more traction electric motors 504 instead of the electric energy store 506, including when the electric energy store 506 has reached a minimum state of charge, and also when the electric energy store 506 is at a nominal level above the minimum state of charge to maintain the state of charge of the electric energy store 506 above the minimum state of charge for as long as possible. In this way this increases the time between charges of the electric energy store 506, which is beneficial when charging points are less prevalent.

[0092] The vehicle 100 is also arranged to charge the electric energy store 506 by running the hydrogen combustion range extender 110 in generator mode by combusting hydrogen. Therefore the electric energy store 506 can be charged even in situations where a charging point is not available but the hydrogen range extender 100 still has access to fuel.

[0093] By using a hydrogen combustion range extender 110 rather than a hydrocarbon fuel range extender, the vehicle 100 meets the necessary zero emission targets of the future. In combination with this, the catalytic system 510 can be used to remove the remaining harmful emissions from combustion so that the vehicle 100 meets necessary nitrous oxide emissions regulations.

[0094] Figure 6 shows part of a vehicle 100 according to examples disclosed herein. In particular, Figure 6 shows a high voltage bus 600 and components of the vehicle 600 connected to the high voltage bus 600. As described herein, multiple components of the vehicle 100 can be connected via a high voltage bus 600, which is beneficial for integrating the hydrogen combustion range extender 110 into the vehicle 100. As shown in Figure 6, Figure 5A and according to examples disclosed herein, the high-voltage bus 600 is connected to the electrically heated catalyst 512, the first power distribution unit 530, the thermal device 300, the e-machine inverter 114, the traction inverter 502 and the electric energy store management module 508. In other examples the electric energy store 506 can be directly connected to the high voltage bus 600. In other examples, the power distribution 550 is also connected to the high voltage bus 600, in particular when the power distribution 550 is embodied as a module / unit according to examples disclosed herein.

[0095] Advantageously therefore the high-voltage bus 600, which is typically already present in vehicles comprising an electric propulsion system, can be used to divert power to systems such as the thermal device 300, or the electrically heated catalyst 512, or the e-machine inverter 514 which have been incorporated into the vehicle 100 with the hydrogen combustion range extender 110.

[0096] Figure 7 shows a method 700 of controlling a vehicle according to examples disclosed herein. The method 700 can be performed by the vehicle 100 described according to examples disclosed herein and referred to in other Figures.

[0097] For the method 700, the vehicle 100 comprises a hydrogen combustion range extender 110. The hydrogen combustion range extender 110 comprises: a fixed-speed piston combustion engine 112; an e-machine inverter 114. The fixed-speed piston combustion engine 112 is arranged to target a single RPM speed whilst combusting, wherein the single RPM speed is the peak efficiency engine speed of the fixed-speed piston combustion engine 112. The e-machine inverter 114 is connected to the crankshaft 116 of the fixed-speed piston combustion engine 112. In a first block 710 of the method 700, the method comprises operating the e-machine inverter 114 in an electric motor mode to target rotating the crankshaft 116 of the fixed-speed piston combustion engine 112 at the single RPM speed, whilst the piston combustion engine 112 is not combusting.

[0098] In a second block 720 of the method 700, the method comprises combusting hydrogen by injecting hydrogen into the piston combustion engine 112 after the e-machine inverter 114 has rotated the crankshaft 116 to the single RPM speed, or within a predetermined tolerance of the single RPM speed.

[0099] In a third block 730 of the method 700, the method comprises targeting combustion of hydrogen to rotate the crankshaft 116 at the single RPM speed.

[00100] In a fourth block 740 of the method 700, the method comprises operating the e-machine inverter 114 in an electric generator mode whilst the piston combustion engine 112 is combusting hydrogen.

[00101] Therefore method 700 advantageously provides a method of controlling a zero emissions vehicle 100 using a hydrogen combustion range extender 100. In examples where the vehicle 100 comprises an electric propulsion system, this can increase the time between charging of an electric energy store of the electric propulsion system and can also be used to charge the electric propulsion system.

[00102] Figure 8 shows part of a method 700 of controlling a vehicle 100 according to examples disclosed herein.

[00103] Block 710 of method 700 is shown as being the last block in Figure 8 and is followed by a dashed line. This is to indicate that blocks of the method 700 following block 710 as illustrated in the examples disclosed herein are included in method 700 shown in Figure 8 but are not present for simplicity.

[00104] As shown in Figure 8, according to examples disclosed herein the method 700 comprises in block 810 heating the fixed-speed piston combustion engine 112 using a thermal management system 400 of the vehicle 100 prior to the combusting of hydrogen in the fixed-speed combustion engine as in block 720.

[00105] As described herein, heating the fixed-speed piston combustion engine 112 using a thermal management system 400, such as the thermal management system 400 illustrated in Figure 4, provides the benefit that when the hydrogen combustion range extender 110 is activated for use, it will provide more efficient combustion compared to if the fixed-speed piston combustion engine was not up to a suitable temperature. According to examples disclosed herein, the fixed-speed piston combustion engine 112 can alternatively or in addition be heated using a thermal device 300 which is connected to a high-voltage bus 600 of the vehicle 100, and the block 810 can comprise heating the combustion engine 112 using the thermal device 300.

[00106] As shown in Figure 8, according to examples disclosed herein the method 700 comprises in block 820, determining, by the vehicle 100, that the hydrogen combustion range extender 110 is to be activated to combust hydrogen before allowing the operating of the e-machine inverter 114 in the electric motor mode in block 710 to target rotating the crankshaft 116 of the fixed-speed piston combustion engine 112.

[00107] A state of charge of an electric energy store 506 of the vehicle 100 being below a first state of charge threshold can be used to determine that the hydrogen combustion range extender 100 is to be activated to combust hydrogen.

[00108] Alternatively or in addition to the state of charge of the electric energy store 506 being below a first state of charge threshold, an operation mode of a high voltage power management module, such as high voltage power management module 550 as described according to examples disclosed herein, of the vehicle can be used to determine that the hydrogen combustion range extender 110 is to be activated to combust hydrogen.

[00109] For example the high-voltage power management module 550 can operate in a first mode of operation where the wheels of the vehicle 100 are driven preferentially using power from the hydrogen combustion range extender 110. Power from the electric energy store 506 may still be used whilst in the process of activating the hydrogen combustion range extender 100 in this mode of operation, or to supplement power from the hydrogen combustion range extender 100, for example in high torque demand. For example the high-voltage power management module 550 can operate in a second mode of operation where the wheels of the vehicle 100 are driven preferentially using both the power from the hydrogen combustion range extender 110 and the power from electric energy store 506. This may be a boost mode to provide a high torque output. For example the high voltage power management module 550 can operate in a third mode of operation where the wheels of the vehicle 100 preferentially driven using the power from the electric energy store 506. Power from the hydrogen combustion range extender 110 may still be used for example to manage the temperature of the electric energy store 506 or to supplement the power provided by the electric energy store 506. Other modes of operation are envisaged.

[00110] As shown in Figure 8, according to examples disclosed herein, the method 700 comprises in block 830, prior to operating the e-machine inverter 114 in the electric motor mode to target rotating the crankshaft of a fixed-speed piston combustion engine at the single RPM speed as in block 710, heating an electrically heated catalyst 512 of the vehicle 100 using power from a high voltage bus 600 of the vehicle 100, and controlling the temperature of a selective catalytic reduction device 514 of the vehicle 100 using heat from the electrically heated catalyst device 512. Advantageously this provides a process of heating the selective catalytic reduction device 514 up to a suitable temperature in the event of a cold start, which means that the selective catalytic reduction device 514 will operate efficiently as soon as the fixed-speed piston combustion engine 112 is activated to combust hydrogen. This is beneficial for the hydrogen combustion range extender 100 which may only be required to combust for small amount of time depending on the requirements of the vehicle 100, which would prevent the selective catalytic reduction device 114 from getting up to an appropriate operating temperature before the combustion engine 112 is de-activated.

[00111] As shown in Figure 8 and according to examples disclosed herein, the method comprises, in block 840, confirming, by the vehicle 100, that the temperature of the selective catalytic reduction device 514 is being controlled using the heat from the electrically heated catalyst device 512 before allowing the operating of the e-machine inverter 114 in an electric motor mode to target rotating the crankshaft 116 of the fixed-speed piston combustion engine 112 at the single RPM speed, as in block 710. This beneficially ensures that the selective catalytic reduction device 514 will operate as intended when combusting hydrogen to meet the necessary emissions regulations.

[00112] As shown in Figure 8 and according to examples disclosed herein, the method comprises, in block 850, confirming that the fixed-speed piston combustion engine 112 has been heated to or is at a minimum temperature before allowing the operating of the e-machine inverter 114 in an electric motor mode to target rotating the crankshaft of a fixed-speed piston combustion engine 112 at the single RPM, as in block 710. This advantageously ensures that the fixed speed piston combustion engine 112 is operating at an appropriate temperature which will ensure maximum economy of the hydrogen fuel stored in a pressure vessel of the vehicle.

[00113] It is to be understood that the order of blocks 810, 820, 830, 840 and 850 in Figure 8 may be changed and that one or more blocks can be omitted.

[00114] Figure 9 shows part of a method 700 of controlling a vehicle 100 according to examples disclosed herein.

[00115] As shown in Figure 9, block 910 which is the first block shown in Figure 9 has a dashed line above it which represents that previous blocks of method 700 shown in examples disclosed herein, for example blocks shown in Figure 7 or 8, can precede the blocks shown in Figure 9. In particular block 710 may precede block 910.

[00116] As shown in Figure 9 and according to examples disclosed herein, the method 700 comprises, in block 910, opening valves on a pressure vessel 520 of the vehicle 100 to allow the injecting of the hydrogen into the piston combustion engine 112 to begin the combusting after the e-machine inverter 114 has rotated the crankshaft to the single RPM speed, as in block 710, wherein coils of the fixed-speed piston combustion engine 112 are activated to enable the combusting of hydrogen.

[00117] As shown in Figure 9 and according to examples disclosed herein, the method 700 comprises, in block 920, confirming stable combustion using lambda feedback after the combusting of hydrogen has begun.

[00118] Alternatively or in addition to this, block 920 comprises confirming stable combustion by monitoring the output voltage of the e-machine inverter 114 after the combusting of hydrogen has begun.

[00119] As shown in Figure 9 and according to examples disclosed herein, the method 700 comprises, in block 930, stopping heating of electrically heated catalyst 512 following confirmation of stable combustion.

[00120] As shown in Figure 9 and according to examples disclosed herein, the method 700 comprises, in block 940, activating Urea / AdBlue management in the selective catalytic reduction device 514 after stopping heating of the electrically heated catalyst 512.

[00121] As shown in Figure 9 and according to examples disclosed herein, the method 700 comprises, in block 950, stopping the combusting of hydrogen based on the state of charge of the electric energy store 506 being above a second state of charge threshold, or stopping combustion of hydrogen based on the operation mode of the high voltage power management module, such as high voltage power management module 550.

[00122] The blocks shown in Figure 9 therefore provide the advantage of managing the stable combustion of hydrogen at the single RPM speed, ensuring that the catalytic system 510 is heated and operates efficiently and that the hydrogen combustion range extender 100 is used appropriately in accordance with the vehicles requirements.

[00123] Figure 10 shows an example controller according to examples disclosed herein.

[00124] The controller 1000 shown in Figure 10, which can also be referred to as a control unit, comprises one or more processors 1010, and one or more memory 1020. The one or more memory 1020 stores computer program instructions 1030. The computer program instructions 1030, when executed by the one or more processors 1010, causes the controller 1000 to perform any of the methods described herein, for example the methods 700 described herein with reference to Figures 7 to 9. The controller 1000 can be the vehicle control unit 540 illustrated in Figure 5A or may be another controller. A control system comprising one or more of the controllers 1000 can be used, with computer program instructions 1030 to perform the methods described herein. In such examples the computer program instructions 1030 stored on the different controllers may comprise different instructions in order to carry out the methods collectively as the system.

[00125] Example components / suppliers for use in the vehicle 100 include, but are not limited to the following: • Fixed-speed piston combustion engine 112: 600CC 2 Cylinder (or other small capacity, low cylinder count engines with minimal frictional losses) • e-machine inverter 114: a three phase permanent magnet electric machine. • Injectors 1121: PWM driven port injector. • Coils 1122 (Ignition): IGBT Driven Coil Pack. • Vehicle control unit 540: Simulink compatible controller • DC / DC Converter / Load Control: Viritech

[00126] The following performance figures can be provided according to examples disclosed herein, but are not limited as such: • Maximum electrical output of e-machine inverter 114: 22KW. • Effective output of e-machine inverter 114 at 400V DC: 20KW • Fixed-speed piston combustion engine 112 maximum output: 25KW • Fixed-speed piston combustion engine 112 operating speed: 5000RPM with a predetermined tolerance of +1- 50 RPM (other speeds are possible, and the tolerance can be optimised depending on the engine used)

[00127] Avoiding cold start, transients and optimising for lean burn at a single engine operating speed allows the engine 112 according to examples can achieve a thermal efficiency of 35% - 40%.

[00128] Given the efficiency of the e-machine and general losses in the system this equates to an energy recovery of around 13 kWh per 1KG of Hydrogen generated at a rate of 20 kWh during operation.

[00129] According to examples, a 2.5KG hydrogen pressure vessel 520 on vehicle 100 with an 8kWh battery system allows for a total energy on vehicle 100 of around 40 kWh allowing for a range of around 150 miles in a small passenger car. Other performance figures are possible with the examples disclosed herein, and optimised for different vehicle requirements.

[00130] In the example of a 8 kWh battery, the system allows for around 30 miles of range at lower speed, electric only (for example in a city) whilst the hydrogen combustion range extender 100 output is sufficient for a cruise speed of around 60mph whilst still providing energy to recharge the battery at a rate of around 4kW.

[00131] The use of existing Viritech Ltd energy management strategies and elements according to examples disclosed herein within the vehicle will allow for boost performance, as combination of battery and hydrogen combustion range extender output, to deliver higher rates of vehicle acceleration than would be possible in isolation providing acceleration performance similar to a conventional vehicle powered by a 100bhp combustion engine.

[00132] Recharging of the electric energy store 506 outside of when the vehicle 100 is running can be accomplished by plug in via an onboard low current (3.3KW) charger or by running the range extender 100 in charge mode where conditions allows which would deliver a full HV battery charge from minimum state of charge in 15-20 minutes.

[00133] According to examples, steel pressure vessels can be used for the hydrogen pressure vessel 520 to provide a low cost, easily manufactured alternative but with a weight compromise. Other materials for the pressure vessels, such as composite overwraps, can be used in other examples.

[00134] The increase in weight using a steel pressure vessel is manageable in that there is a lower overall hydrogen storage requirement compared to hydrogen fuel cell vehicles and thus a smaller physical pressure vessel is required. Furthermore the examples disclosed herein are envisaged for, but not limited to, low overall vehicle performance requirements. Additionally, in the use case for developing countries, the requirement to produce the pressure vessels in the developing country market may be more beneficial than shipping in pressure vessels requiring higher level technical manufacturing processes.

[00135] Examples disclosed herein have included a hydrogen combustion range extender for use in a vehicle, such as automotive vehicle. It’s to be understood that the hydrogen combustion range extender 110 in accordance with the examples described herein, can be used for other applications such as a general-purpose electric generator and for other uses such as providing part of the powertrain for marine use. Hydrogen combustion range extenders according to examples described herein has the advantages of providing a zero emissions electric generator, which could easily be manufactured and / or maintained in developing countries where access to charging infrastructure is limited, due to its use of combustion engines which are easily accessible. The vehicle 100 described herein according to the examples above is shown as being an automotive vehicle, however the vehicle 100 can be other types of vehicles, such as watercraft, aircraft.

[00136] Throughout the description and claims of this specification, the words “comprise” and “contain” and variations of them mean “including but not limited to”, and they are not intended to (and do not) exclude other components, integers or steps. Throughout the description and claims of this specification, the singular encompasses the plural unless the context otherwise requires. In particular, where the indefinite article is used, the specification is to be understood as contemplating plurality as well as singularity, unless the context requires otherwise.

[00137] Features, integers, or characteristics described in conjunction with a particular aspect, embodiment or example of the invention are to be understood to be applicable to any other aspect, embodiment or example described herein unless incompatible therewith. All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and / or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and / or steps are mutually exclusive. The invention is not restricted to the details of any foregoing embodiments. The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

[00138] It will be appreciated that various changes and modifications can be made to the present invention without departing from the scope of the present application.

Claims

1. A vehicle comprising a hydrogen combustion range extender, the hydrogencombustion range extender comprising:a fixed-speed piston combustion engine, arranged to target a single RPM speed whilst combusting, wherein the single RPM speed is the peak efficiency engine speed of the fixed-speed piston combustion engine;an E-machine inverter connected to the crankshaft of the fixed-speed piston combustion engine;the E-machine inverter arranged to operate in an electric motor mode to target rotating the crankshaft of the fixed-speed piston combustion engine at the single RPM speed, whilst the piston combustion engine is not combusting;wherein after the E-machine inverter has rotated the crankshaft to the single RPM speed, or within a predetermined tolerance of the single RPM speed, the hydrogen combustion range extender is arranged to inject hydrogen into the piston combustion engine to begin combustion;wherein the hydrogen combustion range extender is arranged to target combustion of hydrogen to rotate the crankshaft at the single RPM speed;wherein the E-machine inverter is arranged to operate in an electric generator mode whilst the piston combustion engine is combusting hydrogen.

2. The vehicle as claimed in claim 1, wherein the fixed-speed pistoncombustion engine is a port injection engine.

3. The vehicle as claimed in any preceding claim, wherein the vehiclecomprises a high voltage bus.

4. The vehicle as claimed in claim 3, wherein the vehicle is arranged to heatthe fixed-speed piston combustion engine using a thermal device powered by the high voltage bus.

5. The vehicle as claimed in any preceding claim, wherein the vehiclecomprises a thermal management system, wherein the thermal management system is arranged to heat the fixed-speed piston combustion engine using waste heat put into the thermal management system.

6. The vehicle as claimed in any preceding claim, wherein the vehiclecomprises an electrically heated catalyst device and a selective catalytic reduction device.

7. The vehicle as claimed in claim 6, when dependent upon claim 3, whereinthe electrically heated catalyst is heated using power from the high voltage bus, and wherein the vehicle is arranged to control the temperature of the selective catalytic reduction device using heat from the electrically heated catalyst device.

8. The vehicle as claimed in any preceding claim, wherein the vehiclecomprises an electric propulsion system, wherein the electric propulsion system comprises: a traction electric motor; a traction inverter; an electric energy store;wherein the traction electric motor is arranged to provide traction to drive one or more wheels of the vehicle;wherein the traction inverter is connected to the traction electric motor;wherein the hydrogen combustion range extender is arranged to provide electrical power to the electric propulsion system when the e-machine inverter is operating in the electric generator mode, and is arranged to receive electrical power from the electric propulsion system when the e-machine inverter is operating in the electric motor mode.

9. The vehicle as claimed in any preceding claim, wherein the vehiclecomprises a pressure vessel for storing hydrogen.

10. The vehicle as claimed in any preceding claim, wherein the single RPMspeed is 5000 RPM.

11. A method of controlling a vehicle, the vehicle comprising a hydrogencombustion range extender;wherein the hydrogen combustion range extender comprises: a fixed-speed piston combustion engine; an E-machine inverter;wherein the fixed-speed piston combustion engine is arranged to target a single RPM speed whilst combusting, wherein the single RPM speed is the peak efficiency engine speed of the fixed-speed piston combustion engine;wherein the E-machine inverter is connected to the crankshaft of the fixed-speed piston combustion engine;wherein the method comprises:operating the E-machine inverter in an electric motor mode to target rotatingthe crankshaft of a fixed-speed piston combustion engine at the single RPM speed, whilst the piston combustion engine is not combusting;combusting hydrogen by injecting hydrogen into the piston combustion engine after the E-machine inverter has rotated the crankshaft to the single RPM speed, or within a predetermined tolerance of the single RPM speed;targeting combustion of hydrogen to rotate the crankshaft at the single RPM speed;operating the E-machine inverter in an electric generator mode whilst the piston combustion engine is combusting hydrogen.

12. The method as claimed in claim 11, wherein the method comprises heatingthe fixed-speed combustion engine using a thermal management system of the vehicle prior to the combusting of hydrogen in the fixed-speed combustion engine.

13. The method as claimed in any of claims 11 to 12, wherein the methodcomprises determining, by the vehicle, that the hydrogen combustion range extender is to be activated to combust hydrogen before allowing the operating of the e-machine inverter in the electric motor mode to target rotating the crankshaft of a fixed-speed piston combustion engine hydrogen.

14. The method as claimed in claim 13, wherein a state of charge of an electricenergy store of the vehicle being below a first state of charge threshold is used to determine that the hydrogen combustion range extender is to be activated to combust hydrogen.

15. The method as claimed in 13 or 14, wherein an operation mode of a highvoltage power management module of the vehicle is used to determine that the hydrogen combustion range extender is to be activated to combust hydrogen.

16. The method as claimed in any of claims 11 to 15, wherein the methodcomprises, prior to operating the e-machine inverter in the electric motor mode to target rotating the crankshaft of a fixed-speed piston combustion engine at the single RPM speed, heating an electrically heated catalyst of the vehicle using power from a high voltage bus of the vehicle, and controlling the temperature of a selective catalytic reduction device of the vehicle using heat from the electrically heated catalyst device.

17. The method as claimed in claim 16, wherein the method comprisesconfirming, by the vehicle, that the temperature of the selective catalytic reduction device is being controlled using the heat from the electrically heated catalyst device before allowing the operating of the e-machine inverter in an electric motor mode to target rotating the crankshaft of a fixed-speed piston combustion engine at the single RPM speed.

18. The method as claimed in any of claims 11 to 17, wherein the methodcomprises confirming that the fixed-speed piston combustion engine has been heated to or is at a minimum temperature before allowing the operating of the E-machine inverter in an electric motor mode to target rotating the crankshaft of the fixed-speed piston combustion engine.

19. The method as claimed in any of claims 11 to 18, wherein the methodcomprises opening valves on a pressure vessel of the vehicle to allow the injecting of the hydrogen into the piston combustion engine to begin the combusting after the E-machine inverter has rotated the crankshaft to the single RPM speed, wherein coils of the fixed-speed combustion engine are activated to enable the combusting of hydrogen.

20. The method as claimed in any of claims 11 to 19, wherein the methodcomprises confirming stable combustion using lambda feedback after the combusting of hydrogen has begun.

21. The method as claimed in any of claims 11 to 19, wherein the methodcomprises confirming stable combustion by monitoring the output voltage of the E-machine inverter after the combusting of hydrogen has begun.

22. The method as claimed in claim 20 or 21, when dependent upon claim 16,wherein the method comprises stopping heating of electrically heated catalyst following confirmation of stable combustion.

23. The method as claimed in claim 22, wherein the method comprisesactivating Urea / AdBlue management in the selective catalytic reduction device after stopping heating of the electrically heated catalyst.

24. The method as claimed in any of claims 11 to 23, when dependent uponclaim 14 or 15, wherein the method comprises stopping the combusting of hydrogen based on the state of charge of the electric energy store being above a second state of charge threshold, or stopping combustion of hydrogen based on the operation mode of the 5 high voltage power management module.

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