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EP-4101695-B1 - POWER MANAGEMENT SYSTEM FOR A TRANSPORT REFRIGERATION UNIT

EP4101695B1EP 4101695 B1EP4101695 B1EP 4101695B1EP-4101695-B1

Inventors

  • DUCHER, Gael

Dates

Publication Date
20260506
Application Date
20210608

Claims (10)

  1. A vehicle (100) for transporting goods, the vehicle (100) comprising: a transport refrigeration unit (150); an engine (110); and a power management system (400) comprising: a battery unit (440) electrically connected to the transport refrigeration unit (150); and a generator (430) connected to the engine (110), the generator (430) being configured to be driven by the engine (110) and to supply electrical power to the battery unit (440); wherein the power management system (400) is configured to supply electrical power to the transport refrigeration unit (150) from the battery unit (440) responsive to a power demand of the transport refrigeration unit (150); wherein the battery unit (440) comprises: an AC/DC inverter (442) configured to receive electrical power from the generator (430); a DC/AC inverter (443) configured to supply electrical power to the transport refrigeration unit (150); a power storage device (445) configured to receive electrical power from the AC/DC inverter (442), and supply electrical power to the DC/AC inverter (443); and a DC/DC converter (444) connected to each of the power storage device (445), the AC/DC inverter (442) and the DC/AC inverter (443); wherein the generator (430) is mechanically connected to the engine (110), the generator being configured to be mechanically driven by the engine (110); and wherein the generator (430) is coupled to the engine (110) via a clutch (424), wherein the power management system (400) is configured to selectively engage and/or disengage the clutch (424), such that the generator (430) selectively decouples from and/or couples to the engine (110); characterised in that : the power management system (400) comprises a controller (441) configured to monitor a speed of the vehicle (100); wherein the controller (441) is configured to determine that the vehicle (100) is in a first state and engage the clutch (424) when the vehicle (100) is in the first state, wherein the speed of the vehicle (100) is increasing in the first state; and wherein the controller (441) is configured to determine that the vehicle (100) is in a second state and disengage the clutch (424) when the vehicle (100) is in the second state, wherein the speed of the vehicle (100) is substantially constant in the second state.
  2. A vehicle (100) as claimed in claim 1, wherein the engine (110) comprises a power take-off (420), and wherein the engine (110) is configured to mechanically drive the generator (430) via the power take-off (420).
  3. A vehicle (100) as claimed in claim 1 or 2, wherein the generator (330) is coupled to the engine (110) via a variable gearing arrangement (322).
  4. A vehicle (100) as claimed in claim 1, 2 or 3, wherein the controller (441) is configured to monitor a brake pedal position of the vehicle (100); and wherein the controller (441) is configured to determine that the vehicle (100) is in a third state and disengage the clutch (424) when the vehicle (100) is in the third state, wherein the brake pedal is engaged in the third state.
  5. A vehicle (100) as claimed in any preceding claim, wherein the controller (441) is configured to monitor a power level of the battery unit (440); wherein the controller (441) is configured to determine that the vehicle (100) is in a fourth state and disengage the clutch (424) when the vehicle (100) is in the fourth state, wherein the power level of the battery unit (440) is below a first threshold in the fourth state; and/or wherein the controller (441) is configured to determine that the vehicle (100) is in a fifth state and engage the clutch (424) when the vehicle (100) is in the fifth state, wherein the power level of the battery unit (440) is above a second threshold in the fifth state.
  6. A vehicle (100) as claimed in any preceding claim, wherein the battery unit (440) is rechargeable; and wherein the battery unit (440) is configured to recharge when the electrical power supplied from the generator (430) to the battery unit (440) exceeds the power demand of the transport refrigeration unit (150).
  7. A vehicle (100) as claimed in any preceding claim, wherein the vehicle (100) is a rigid truck.
  8. A method of powering a transport refrigeration unit (150) housed within a vehicle (100) comprising an engine (110), the method comprising: mechanically driving a generator (430) using the engine (110), wherein the generator (430) is mechanically connected to the engine (110) via a clutch (424); supplying electrical power generated by the generator (430) to a battery unit (440) by: receiving electrical power from the generator (430) using an AC/DC inverter (442) of the battery unit (440); supplying electrical power from the AC/DC inverter (442) to a DC/DC converter (444) of the battery unit (440); and supplying electrical power to a power storage device (445) of the battery unit (440) using the DC/DC converter (444); supplying electrical power to the transport refrigeration unit (150) using the battery unit (440), responsive to a power demand of the transport refrigeration unit (150) by: receiving electrical power from the power storage device (445) using the DC/DC converter (444); supplying electrical power to a DC/AC inverter (443) of the battery unit (440) using the DC/DC converter (444); supplying electrical power to the transport refrigeration unit (150) using the DC/AC inverter (443); controlling the clutch (424) by selectively engaging the clutch (424) to decouple the generator (430) from the engine (110), and selectively disengaging the clutch (424) to couple the generator (430) to the engine (110); monitoring a speed of the vehicle (100); determining that the vehicle (100) is in a first state and engaging the clutch (424) when the vehicle (100) is in the first state, wherein the speed of the vehicle (100) is increasing in the first state; and determining that the vehicle (100) is in a second state and disengaging the clutch (424) when the vehicle (100) is in the second state, wherein the speed of the vehicle (100) is substantially constant in the second state.
  9. A method as claimed in claim 9, the method comprising: monitoring a power level of the battery unit (440); and controlling the clutch (424) based on the power level of the battery unit (440).
  10. A method as claimed in claim 8 or 9, the method further comprising: recharging the battery unit (440) when a generation rate of the generator (430) exceeds the power demand of the transport refrigeration unit (150).

Description

The present invention relates to a vehicle for transporting goods, and a method of powering a transport refrigeration unit. Transport refrigeration units (TRUs) transport perishable or temperature-sensitive goods and consumables within logistics networks. TRUs generally regulate a monitored environment within a storage area, such as a container or trailer of a vehicle, where the goods are to be stored during transit. The monitored environment is regulated using a refrigeration system or the like, which in turn is powered by an energy source. So that the TRU is able to adequately regulate the monitored environment and hence preserve the goods it transports, the energy source is required to provide a stable source of power to the TRU. One such stable energy source which is used to power a TRU is a generator driven hydraulically by the internal combustion engine of the vehicle which houses the TRU. Due to the engine driving the generator via a hydraulic mechanism, the generator speed remains substantially constant such that the electrical power generated by the generator remains stable. As such the TRU is reliably powered by the generator. The hydraulic mechanism generally comprises a hydraulic pump coupled to the engine, and a hydraulic motor connected to the generator. Hydraulic lines run between the hydraulic pump and the hydraulic motor, and thus complete a fluid circuit. As the engine runs, the hydraulic pump is driven at a varying speed. However, the displacement of the hydraulic pump (i.e. the pump stroke) can be varied such that a constant pressure and flow is maintained at the hydraulic motor. Accordingly, the generator can always be driven at a stable speed, which in turn results in the generator generating a stable source of power for the TRU. EP 3647088 A1 discloses methods and systems for augmenting a vehicle powered transport climate control system. EP 4077002 A1 is comprised in the state of the art according to Article 54(3) EPC, and discloses a system for PTO-driven refrigeration including a generator that is configured to be mechanically connected to a power take-off. US 2020/207184 A1 discloses a vehicle according to the preamble of claim 1 with a transport climate control system including a controller. The controller determines whether a regulatory compliance at a current location is restricting and/or preventing the use of a prime mover for powering the transport climate control system while in transit. In such situations, the prime mover can be decoupled from the transport climate control system using a clutch. Whilst existing TRU systems are suitable for their intended purpose, a demand exists for improved TRU systems. Viewed from a first aspect of the present invention, there is provided a vehicle for transporting goods according to claim 1. By mechanically driving the generator using the engine, the generator being mechanically connected to the engine, the rate at which the generator generates electrical power will depend on a speed of the engine. Accordingly, when the engine speed increases/decreases, the electricity generation rate of the generator will also correspondingly increase/decrease. The power management system is configured to use a battery unit to harvest the generated power, and to supply electrical power to the transport refrigeration unit (TRU) from the battery unit responsive to a power demand of the TRU. Consequently, the requisite power to maintain a desired output of the TRU can be met. That is, the power management system may dynamically output power as required by the TRU. Accordingly, an environment of the vehicle in which goods are transported (i.e. a portion of the vehicle regulated by the TRU) can be effectively regulated and hence a condition of the goods may be reliably preserved. The provision of a power management system which is configured to supply power to the TRU responsive to a power demand of the TRU removes the need to provide a mechanism between the engine and the generator which maintains a substantially constant, or sustained, generator speed (and hence a substantially constant, or sustained, electrical power output at the generator). As such, it is not necessary to provide mechanisms, such as a hydraulic mechanism, which maintains a constant speed output at the generator, when driven by the engine. Mechanically driving the generator by a mechanical connection to the engine rather than a hydraulic mechanism may have a number of advantages. For example, mechanically connecting the generator to the engine may be generally cheaper than a hydraulic connection, and hence the cost of the vehicle components may be reduced. Further, mechanical connections may be less complex in regards to their installation and/or maintenance when compared to hydraulic connections, and hence costs associated in each of these regards may also be reduced. The phrase 'mechanically driven' means that the generator is configured to be driven by the engine via a mechanical inte