Scalable Multi-Port Converters for Solar Electric Vehicles

Abstract

The present invention relates to a three-port isolated active bridge DC-DC power converter comprising a control unit, a first primary side port, a second primary side port, two primary side switching elements, a blocking switch, a secondary side port, and two secondary side switching elements. The control unit is configured to open and close the blocking switch to prevent and allow power flow between the primary side and the secondary side of the power converter. The control unit is configured to control the two primary side switching elements and the two secondary side switching elements to convert power between the primary side port and the secondary side port. The present invention further relates to a three-port isolated active bridge DC-DC power converter system, a multi-port isolated active bridge DC-DC power converter, a multi-port isolated active bridge DC-DC power converter system, a solar power assembly, and a vehicle.

Description

Technical Field

[0001] The present invention relates to a three-port isolated active bridge DC-DC power converter for converting power between a first primary port, a second primary port, and a secondary port. The present invention further relates to a three-port isolated active bridge DC-DC power converter system comprising a plurality of three-port isolated active bridge DC-DC power converters. The present invention further relates to a multi-port isolated active bridge DC-DC power converter for converting power between a plurality of first primary ports, a second primary port, and a secondary port. The present invention further relates to a multi-port isolated active bridge DC-DC power converter system comprising a plurality of multi-port isolated active bridge DC-DC power converters. The present invention further relates to a solar power assembly comprising a plurality of solar power generation units and a power converter system. The present invention further relates to a vehicle comprising the solar power assembly.

Background Art

[0002] Vehicles, particularly vehicles that are at least partially, optionally fully, powered by renewable energy, particularly vehicles powered by a power generation unit such as a solar panel or a fuel cell, typically require a power converter for converting power between a generator, a power consumer, and power storage. For example, a typical architecture of a solar-powered vehicle includes a low-voltage bus and a high-voltage bus. The low-voltage bus supplies power to the low-voltage electrical components of the vehicle and typically includes a low-voltage battery for storing power. The high-voltage bus supplies power to the high-voltage electrical components of the vehicle and typically includes a high-voltage battery for storing power, typically having a larger capacity than the low-voltage battery. In this exemplary architecture, typically, the power generated by the power generation unit needs to be converted to the low-voltage bus and the high-voltage bus. Further, the power stored in the high-voltage battery is sometimes converted to the low-voltage bus.

[0003] In the prior art, often multiple power converters are used. For example, the power generation unit is a photovoltaic power generation unit. In this example, the energy of the photovoltaic power generation unit is provided to either a low-voltage battery or a high-voltage battery having a maximum power point tracker. A separate isolated power converter is used to convert energy between the low-voltage battery and the high-voltage battery. Due to the curvature of the roof and the shadow on the photovoltaic power generation unit, the photovoltaic power generation unit receives different solar irradiances in some cases. The different solar irradiances received by the photovoltaic power generation unit result in different output currents for each photovoltaic power generation unit. When the photovoltaic power generation units are connected in series to generate an appropriate output voltage, the photovoltaic power generation unit with the least amount of irradiation limits the maximum power point current. In a particular solution seen in the prior art, the limiting photovoltaic power generation unit is bypassed, and as a result, all the power of that photovoltaic power generation unit is lost. Other solutions include reducing the number of photovoltaic power generation units, using a high-voltage gain maximum power point tracker, or using a delta maximum power point tracker that redistributes power among the photovoltaic power generation units. However, such solutions are often proposed for systems where the photovoltaic power generation units receive approximately the same solar irradiance. In the prior art, other solutions with high-voltage outputs for solar irradiance have been proposed, which raise safety concerns. In particular, when a vehicle incorporating this solution is involved in a collision, the photovoltaic power generation unit cannot be turned off, which means that any rescue team members and / or drivers may be exposed to these high voltages.

[0004] Furthermore, from the state of the art, multi-port power converters are known. In some of these solutions, multi-port power converters are described that provide fully isolated power conversion between multiple power sources and sinks. However, insulation between photovoltaic units is typically not required and reduces the efficiency of these power converters. In other solutions, multiple power inputs are combined and a single switch is provided for each input. As a result, only one input, i.e., only one photovoltaic unit, can be made active simultaneously. In yet other solutions, a multi-port power converter having two non-insulated power ports and one insulated power port is presented. However, some problems remain in these architectures. First, the insulated ports of these architectures are unidirectional and prevent power from flowing in and out of the insulated port. In these architectures, additional power converters are added to enable power flow in both directions. Second, for each additional input, i.e., for each additional photovoltaic unit, an additional set of switching elements in the power converter is required. Third, due to the high voltage gain for converting power to a high voltage bus, excessive losses occur.

[0005] International Publication No. WO 2019 / 199964 describes a vehicle-mounted charger for bidirectional charging of low / high voltage batteries. The in-vehicle charger system includes an on-board charger (OBC) and an integrated transformer subsystem. The OBC also includes a bidirectional power factor correction (PFC) rectifier to which the in-vehicle charger system is connected to the power grid. The topology of the OBC system can achieve grid-to-vehicle, vehicle-to-grid, and HV-to-LV operations. A buck-to-buck switch (or relay) is required on the tertiary side of the DC / DC converter to disconnect the power flow during grid-to-vehicle (G2V) charging or vehicle-to-grid (V2G) discharging operations. In a resonance-based topology, the charger subsystem has either a half-bridge or a full-bridge configuration.

[0006] U.S. Patent Application Publication No. 2020 / 398686 describes a combined converter circuit for an electric vehicle, including a bidirectional converter circuit configured to convert a voltage from a high-voltage power bus connected to the main battery of the electric vehicle to a reduced or stepped-down voltage corresponding to an auxiliary battery or an auxiliary power bus. The auxiliary power module (APM) includes a high-voltage (HV) side and a low-voltage (LV) side. Two HV power switches are provided to operate the circuit at the required duty ratio. A 14V power supply is provided on the LV side. Two capacitors are utilized on the HV side to divide the voltage. Two capacitors are also provided on the secondary side to divide the transformed voltage.

[0007] U.S. Patent Application Publication No. 2020 / 266717 describes a transformer having a primary winding, a secondary winding, and a tertiary winding, a primary converter connected to the primary winding including a plurality of first switching elements, a secondary converter connected to the load and the secondary winding including a plurality of second switching elements, a tertiary converter connected to the tertiary winding including a plurality of third switching elements and a capacitor, and a control unit that performs switching control on the plurality of first switching elements, the plurality of second switching elements, and the plurality of third switching elements such that power is supplied from the primary converter to the secondary converter while maintaining a constant voltage supplied to the load, and power is supplied from the primary converter to the tertiary converter while maintaining a constant current supplied to the capacitor.

[0008] U.S. Patent Application Publication No. 2016 / 016479 describes an integrated insulated on-vehicle charger for a plug-in electric vehicle including an ac-dc converter and a dual-output dc-dc resonant converter for both an HV traction battery and an LV load. Additionally, the integrated insulated on-vehicle charger may be configured as unidirectional or bidirectional and be capable of delivering power from an HV split battery to the grid for vehicle-to-grid (V2G) applications. The integrated charger is configured for various operating modes including grid-to-vehicle (G2V), vehicle-to-grid (V2G), and high voltage to low voltage HV to LV (H2L) charging. SUMMARY OF THE INVENTION PROBLEMS TO BE SOLVED BY THE INVENTION

[0009] The object of the present invention is to provide a DC-DC power converter that improves the state-of-the-art technology, or to provide an alternative to the state-of-the-art technology. A further object of the present invention is to provide a DC-DC power converter system in which the DC-DC power converter system is a combination of a plurality of DC-DC power converters. The DC-DC power converter system provides a plurality of first primary-side ports. A further object of the present invention is to provide a photovoltaic power assembly in which a plurality of photovoltaic units are connected to the power converter system. A further object of the present invention is to provide a vehicle equipped with a photovoltaic power assembly for supplying power to a low-voltage battery and a high-voltage battery.

Means for Solving the Problems

[0010] According to a first aspect of the present invention, the object is achieved by a three-port isolated active bridge DC-DC power converter comprising a control unit, a primary side, a secondary side, and a blocking switch. The primary side comprises a first primary-side port, a second primary-side port, two primary-side switching elements, a primary-side converter inductance, and a primary-side transformer winding. The first primary-side port and the second primary-side port are separate ports, i.e., there are at least two primary-side ports. In a preferred embodiment, the primary side comprises a single first primary-side port and a single second primary-side port, i.e., in this embodiment, the primary side comprises exactly two primary-side ports. The two primary-side switching elements and the primary-side converter inductance are arranged to form a half-bridge arrangement for bidirectional power conversion between the first primary-side port and the second primary-side port. The control unit is configured to control the two primary-side switching elements to convert power between the first primary-side port and the second primary-side port. The primary-side switching elements are, for example, JFETs, IGBTs, GaN HEMTs, or MOSFETs.

[0011] The primary circuit is arranged to form a power converter between a first primary port and a second primary port. For example, when the voltage is stepped down between the first primary port and the second primary port, the primary side forms a step-down converter between the first primary port and the second primary port. As another example, when the voltage is stepped up between the first primary port and the second primary port, the primary side forms a step-up converter between the first primary port and the second primary port. To improve the efficiency of the power converter, the first primary port and the second primary port are connected without insulation.

[0012] The secondary side includes a secondary port, two secondary switching elements, and a secondary transformer winding. In a preferred embodiment, the secondary side includes a single secondary port and a single secondary transformer winding. The secondary transformer winding is magnetically coupled to the primary transformer winding. The two primary switching elements, the primary transformer winding, the two secondary switching elements, and the secondary transformer winding are arranged to form an isolated DC-DC converter between the primary side and the secondary side. In other words, the two primary switching elements, the primary transformer winding, the two secondary switching elements, and the secondary transformer winding are arranged to form an isolated DC-DC converter between the primary port and the secondary port. The control unit is further configured to control the two primary switching elements and the two secondary switching elements to convert power between the primary port and the secondary port. The secondary switching elements are, for example, JFETs, IGBTs, GaN HEMTs, or MOSFETs.

[0013] The first primary port, the second primary port, and the secondary port each comprise a pair of terminals, which are used, for example, to connect to an external electrical circuit. For example, the second primary port is connected to a low voltage bus, which connects a three-port isolated active bridge DC-DC power converter to a low voltage battery. For example, the secondary port is connected to a high voltage bus, which connects a three-port isolated active bridge DC-DC power converter to a high voltage battery. For example, the first primary port is connected to a power generation unit. The power generation unit is, for example, a solar power generation unit, or a fuel cell, or a wind turbine. For example, the three-port isolated active bridge DC-DC power converter is used in a wind power plant. In this example, for instance, a wind power generation unit such as a wind turbine is connected to the first primary port. In another example, the three-port isolated active bridge DC-DC power converter is used in a solar power plant. In this example, for instance, a solar power generation unit such as a solar panel is connected to the first primary port. In yet another example, the three-port isolated active bridge DC-DC power converter is used in a fuel cell electric vehicle. In this example, the fuel cell is connected to the first primary port.

[0014] Accordingly, the three-port isolated active bridge DC-DC power converter provides an integrated architecture capable of bidirectional power conversion between the first primary port, the secondary port, and the second primary port. The bidirectional power flow is achieved by using primary side switching elements and secondary side switching elements configured to enable the bidirectional power flow. Further, the magnetic coupling of the primary side transformer winding and the secondary side transformer winding is arranged such that power flows between the primary side and the secondary side.

[0015] The three-port isolated active bridge DC-DC power converter further comprises a blocking switch. The control unit is further configured to open the blocking switch to prevent power flow between the primary side and the secondary side, and to close the blocking switch to enable power flow between the primary side and the secondary side. The first primary port and the second primary port are configured on the primary side, and the secondary port is configured on the secondary side. When power flow between the primary side and the secondary side is not required, it is desirable to prevent excitation of the transformer core, which is formed by the primary transformer winding and the secondary transformer winding. To prevent excitation of the transformer core, the three-port isolated active bridge DC-DC power converter comprises a blocking switch. The blocking switch is controlled by a control unit, which opens and closes the blocking switch. When the blocking switch is closed, power flow between the primary side and the secondary side is enabled. This may be the case, for example, to enable power flow between the first primary port and the secondary port, and / or between the second primary port and the secondary port. When the blocking switch is open, power flow between the primary side and the secondary side is prevented. This may be the case, for example, to exclusively enable power flow between the first primary port and the second primary port. In this case, the secondary side is bypassed, and the transformer core formed by the primary transformer winding and the secondary transformer winding is not excited or is minimally excited.

[0016] In an embodiment according to the first aspect of the present invention, the first primary port is an input power port arranged to be connected to an input power source. For example, the input power source is a fuel cell. As another example, the input power source is a photovoltaic power generation unit. Further, in this embodiment, the second primary port is a low-voltage port arranged to be connected to a low-voltage power storage. For example, the low-voltage power storage is a low-voltage battery of a vehicle. Further, in this embodiment, the secondary port is a high-voltage port arranged to be connected to a high-voltage power storage. For example, the high-voltage power storage is a high-voltage battery of a vehicle.

[0017] In an embodiment according to the first aspect of the present invention, two primary switching elements and a primary converter inductance are arranged to form a buck converter or a boost converter.

[0018] In an embodiment according to the first aspect of the present invention, the primary side includes a blocking switch.

[0019] In an embodiment according to the first aspect of the present invention, the blocking switch is connected in series with the primary transformer winding. By connecting the blocking switch in series with the primary transformer winding, the blocking switch is arranged to cut off the power flow between the primary side and the secondary side when it is open. Specifically, when the blocking switch is opened, the power flow through the primary transformer winding and the secondary transformer winding is prevented. When the blocking switch is closed, the power flow through the primary transformer winding and the secondary transformer winding is enabled.

[0020] In an embodiment according to the first aspect of the present invention, the secondary side includes a blocking switch.

[0021] In an embodiment according to the first aspect of the present invention, the blocking switch is connected in series with the secondary transformer winding. By connecting the blocking switch in series with the secondary transformer winding, the blocking switch is arranged to cut off the flow of power between the primary side and the secondary side when it is open. Specifically, when the blocking switch is opened, the flow of power through the primary transformer winding and the secondary transformer winding is prevented. When the blocking switch is closed, the flow of power through the primary transformer winding and the secondary transformer winding is enabled.

[0022] In an embodiment according to the first aspect of the present invention, the primary side comprises two additional primary side switching elements. The four primary side switching elements are arranged to form a primary side full bridge.

[0023] The advantage of arranging two additional primary side switching elements and having the four primary side switching elements form a primary side full bridge is that, in some cases, the reactive current is minimized by using the phase shift between the four primary side switching elements and the two secondary side switching elements. A further advantage is that the full input voltage, i.e., the voltage supplied through the first primary side port, is utilized in the primary side winding, reducing the current. In the case of a half bridge, only half of the input voltage, i.e., half of the voltage supplied through the first primary side port, is available. Alternatively, the input voltage is the voltage supplied to the primary side through the transformer core.

[0024] In an embodiment according to the first aspect of the present invention, the secondary side comprises two additional secondary side switching elements. The four secondary side switching elements are arranged to form a secondary side full bridge.

[0025] Two additional secondary-side switching elements are arranged such that the advantage of the four secondary-side switching elements forming a secondary-side full bridge is that the reactive current is minimized using the phase shift between the four secondary-side switching elements and the primary-side switching element. A further advantage is that the full input voltage, i.e., the voltage supplied to the secondary side via the transformer core, is utilized at the secondary port. In the case of a half bridge, only half of the input voltage, i.e., half of the voltage supplied to the secondary side via the transformer core, is available. Alternatively, the input voltage is the voltage supplied via the secondary port.

[0026] In an embodiment according to a first aspect of the invention, the blocking switch comprises two blocking switching elements. The two blocking switching elements are connected in inverse series. By connecting the two blocking switching elements in inverse series, it is possible to prevent the flow of power in both directions, i.e., from the primary side to the secondary side and from the secondary side to the primary side. To close the blocking switch, the control unit is configured to close the two blocking switching elements comprised by the blocking switch. To open the blocking switch, the control unit is configured to open the two blocking switching elements comprised by the blocking switch. The blocking switching element is, for example, a JFET, an IGBT, a GaN HEMT, or a MOSFET.

[0027] In an embodiment according to the first aspect of the present invention, the control unit is configured to control a primary switching element and a secondary switching element to generate a phase shift that determines power transfer between the primary side and the secondary side. When the blocking switch is closed, power transfer between the primary side and the secondary side is enabled. In other words, power is transferred between one of the first primary port and the second primary port and the other secondary port. Power transfer to and from the secondary port is mainly controlled by the phase shift between the primary port, that is, the primary port including the first primary port and the second primary port, and the secondary port. The phase shift between the primary port and the secondary port is achieved by the control unit controlling the duty cycle of the primary switching element and the duty cycle of the secondary switching element.

[0028] In an embodiment according to the first aspect of the present invention, the three-port isolated active bridge DC-DC power converter is configured to enable the flow of power from the first power port to the second power port. The first power port is one of the first primary port, the second primary port, and the secondary port. The second power port is one of the first primary port, the second primary port, and the secondary port. The first power port and the second power port are different.

[0029] In some cases, an exclusive flow of power between two ports is desired.

[0030] For example, a flow of power from a first primary port to a second primary port is desired. For example, this may be the case when all the power flowing into the first primary port is required to supply power to components connected to the second primary port. In this example, the blocking switch is opened by the control unit to prevent any flow of power between the primary side and the secondary side. Further, the primary side circuit, particularly the primary side switching element, is controlled by the control unit to convert power from the second primary port to the first primary port. In this case, the converter behaves as, for example, a buck converter or a boost converter. Specifically, the duty cycle of the primary side switching element determines the power transfer from the first primary port to the second primary port.

[0031] As another example, a flow of power from a first primary port to a secondary port is desired. In this case, the power flowing into the first primary port can be transferred to the secondary side and, for example, stored in a power storage, such as a battery. In another example, this power can be used to supply power to components connected to the secondary port. In this embodiment, the blocking switch is closed by the control unit to allow power to flow between the primary side and the secondary side. Further, the primary side circuit, particularly the primary side switching element, as well as the secondary side circuit, particularly the secondary side switching element, are controlled by the control unit to convert power from the first primary port to the secondary port. In this case, the converter behaves as an isolated DC-DC power converter between the first primary port and the secondary port. The power transfer to the secondary port is mainly controlled by the phase shift between the first primary port and the secondary port. This phase shift is achieved by the control unit controlling the duty cycle of the primary side switching element and the duty cycle of the secondary side switching element. In this case, a positive phase shift between the primary side switching element and the secondary side switching element achieves the power transfer from the first primary port to the secondary port.

[0032] As yet another example, a flow of power from the secondary port to the second primary port is desired. For example, this may be the case where power from the secondary port is needed to supply power to a component connected to the second primary port. In this example, power is transferred from the secondary port to the second primary port. In this example, the blocking switch is closed by the control unit, enabling power to flow between the primary side and the secondary side. Further, the primary side circuit, particularly the primary side switching element, and the secondary side circuit, particularly the secondary side switching element, are controlled by the control unit to transfer power from the secondary port to the second primary port. In this case, the converter behaves as an isolated DC-DC power converter between the secondary port and the second primary port. The power transfer to the second primary port is mainly controlled by a phase shift between the secondary port and the second primary port. This phase shift is achieved by the control unit controlling the duty cycle of the primary side switching element and the duty cycle of the secondary side switching element. In this case, a positive phase shift between the secondary side switching element and the primary side switching element achieves the power transfer from the secondary port to the second primary port. A positive phase shift between the secondary port and the second primary port means a negative phase shift between the second primary port and the secondary port.

[0033] In other examples, a flow of power from the second primary port to the first primary port, or from the secondary port to the first primary port, is enabled.

[0034] In an embodiment according to a first aspect of the present invention, a three-port isolated active bridge DC-DC power converter is configured to enable power flow from a first power port and a second power port to a third power port. The first power port is one of a first primary port, a second primary port, and a secondary port. The second power port is one of a first primary port, a second primary port, and a secondary port. The third power port is one of a first primary port, a second primary port, and a secondary port. The first power port, the second power port, and the third power port are different from each other.

[0035] In some cases, power flow from two ports to another port is desired.

[0036] For example, power flow from the first primary port and the second primary port to the secondary port is desired. In this case, the power flowing into the first primary port and the power flowing into the second primary port are transmitted to the secondary side and can be stored, for example, in a power storage, such as in a battery. In another example, this power can be used to supply power to components connected to the secondary port. In this embodiment, the blocking switch is closed by the control unit, enabling power to flow between the primary side and the secondary side. Further, the primary side circuit, particularly the primary side switching element, and the secondary side circuit, particularly the secondary side switching element, are controlled by the control unit to convert power from the first primary port and the second primary port to the secondary port. In this case, the converter behaves as an isolated DC-DC power converter between the two primary ports and the secondary port. Power transmission to the secondary port is mainly controlled by the phase shift between the primary port and the secondary port. This phase shift is achieved by the control unit controlling the duty cycle of the primary side switching element and the duty cycle of the secondary side switching element. In this case, a positive phase shift between the primary side switching element and the secondary side switching element achieves power transmission from the first primary port and the second primary port to the secondary port.

[0037] As another example, power flow from the secondary port and the first primary port to the second primary port is desired. For example, this is the case when power from the secondary port and the first primary port is required to supply power to a component connected to the second primary port. In this example, power is transferred from the secondary port and the first primary port to the second primary port. In this example, the blocking switch is closed by the control unit, enabling power to flow between the primary side and the secondary side. Further, the primary side circuit, particularly the primary side switching element, and the secondary side circuit, particularly the secondary side switching element, are controlled by the control unit to convert power from the secondary port to the second primary port. In this case, the converter behaves as an isolated DC-DC power converter between the secondary port and the second primary port. Power transfer to the second primary port is mainly controlled by the phase shift between the secondary port and the second primary port. This phase shift is achieved by the control unit controlling the duty cycle of the primary side switching element and the duty cycle of the secondary side switching element. In this case, a positive phase shift between the secondary side switching element and the primary side switching element achieves power transfer from the secondary port to the second primary port. A positive phase shift between the secondary port and the second primary port means a negative phase shift between the second primary port and the secondary port. Further, the primary side circuit, particularly the primary side switching element, is controlled by the control unit to convert power from the first primary port to the second primary port. In this case, the converter additionally behaves as a buck converter or a boost converter. Specifically, the duty cycle of the primary side switching element determines the power transfer from the first primary port to the second primary port.

[0038] In another example, power flow from the second primary port and the secondary port to the first primary port is enabled.

[0039] In an embodiment according to the first aspect of the present invention, a three-port isolated active bridge DC-DC power converter is configured to enable the flow of power from a first power port to a second power port and a third power port. The first power port is one of a first primary port, a second primary port, and a secondary port. The second power port is one of a first primary port, a second primary port, and a secondary port. The third power port is one of a first primary port, a second primary port, and a secondary port. The first power port, the second power port, and the third power port are different from each other.

[0040] In some cases, the flow of power from a single port to the other two ports may be desired.

[0041] For example, power flow from a first primary port to a second primary port and a secondary port is desired. In this case, the power flowing into the first primary port is transmitted to the second primary port and the secondary port and can be stored, for example, within a power storage, such as within a battery. In another example, this power can be used to supply power to components connected to the secondary port and / or components connected to the second primary port. In this embodiment, the blocking switch is closed by the control unit, enabling power to flow between the primary side and the secondary side. Further, the primary side circuit, particularly the primary side switching element, and the secondary side circuit, particularly the secondary side switching element, are controlled by the control unit to convert power from the first primary port to the secondary port. In this case, the converter behaves as an isolated DC-DC power converter between the first primary port and the secondary port. Power transmission to the secondary port is mainly controlled by the phase shift between the first primary port and the secondary port. This phase shift is achieved by the control unit controlling the duty cycle of the primary side switching element and the duty cycle of the secondary side switching element. In this case, a positive phase shift between the primary side switching element and the secondary side switching element achieves power transmission from the first primary port to the secondary port. Further, the primary side circuit, particularly the primary side switching element, is controlled by the control unit to convert power from the first primary port to the second primary port. In this case, the converter additionally behaves as a buck converter or a boost converter. Specifically, the duty cycle of the primary side switching element determines power transmission from the first primary port to the second primary port.

[0042] As another example, power flow from the secondary port to the first primary port and the second primary port is desired. For example, this is the case when power from the secondary port is required to supply components connected to the first primary port and components connected to the second primary port. In this example, power is transferred from the secondary port to the first primary port and the second primary port. In this example, the blocking switch is closed by the control unit, enabling power to flow between the primary side and the secondary side. Further, the primary side circuit, particularly the primary side switching element, and the secondary side circuit, particularly the secondary side switching element, are controlled by the control unit to convert power from the secondary port to the first primary port and the second primary port. In this case, the converter behaves as an isolated DC-DC power converter between the secondary port and the primary port. Power transfer to the first primary port and the second primary port is mainly controlled by the phase shift between the secondary port and the primary port. This phase shift is achieved by the control unit controlling the duty cycle of the primary side switching element and the duty cycle of the secondary side switching element. In this case, a positive phase shift between the secondary side switching element and the primary side switching element achieves power transfer from the secondary port to the first primary port and the second primary port. A positive phase shift between the secondary port and the primary port means a negative phase shift between the primary port and the secondary port.

[0043] In another example, power flow from the second primary port to the first primary port and the secondary port is enabled.

[0044] According to a second aspect of the present invention, the object is achieved by a three-port isolated active bridge DC-DC power converter system comprising a plurality of three-port isolated active bridge DC-DC power converters according to the first aspect of the present invention, a first system port, and a second system port. The plurality of three-port isolated active bridge DC-DC power converters are coupled in parallel via their second primary ports so as to form the first system port. The plurality of three-port isolated active bridge DC-DC power converters are coupled in series via their secondary ports so as to form the second system port.

[0045] To expand the power converter for more power inputs, the three-port isolated active bridge DC-DC power converter system comprises a plurality of three-port isolated active bridge DC-DC power converters. Thus, a plurality of first primary ports are available for the three-port isolated active bridge DC-DC power converter system. Thus, the power converter system is configured to be connected to, for example, a plurality of power generation units. The power generation unit is, for example, a solar power generation unit, or a fuel cell, or a wind turbine.

[0046] It is an object to provide a power converter system having a single secondary port and a single second primary port. To achieve this object, the secondary ports of a three-port isolated active bridge DC-DC power converter are connected in series. This forms a second system port. By connecting the secondary ports of the power converter provided by the power converter system in series, it is possible to reduce the voltage gain required between the primary side and the secondary side. Further, the voltage ratings of the semiconductors used in the circuit of the three-port isolated active bridge DC-DC power converter system, namely, the primary side switching element, the secondary side switching element, and the blocking switch, are reduced. This improves the reliability of the system and reduces its cost. Further, in this architecture, a high dynamic output voltage range of the second system port is achieved. For example, when the power input from the first primary port of the three-port isolated active bridge DC-DC power converter provided by the power converter system is reduced, the output voltage, i.e., the voltage of the secondary port, is compensated. For example, when the solar radiation amount of the solar power generation unit connected to the first primary port is reduced, the power input from the first primary port is reduced. In one example, the reduced input power is compensated by transferring power from the first primary port to the first system port instead of the second system port. In an alternative example, the reduced input power is compensated by additionally transferring power from the first system port to the second system port. In a further alternative example, the reduced input power is compensated by additionally transferring power from the second system port to the first system port.

[0047] In an embodiment according to a second aspect of the present invention, the first system port is a low voltage port arranged to be connected to a low voltage power storage, and the second system port is a high voltage port arranged to be connected to a high voltage power storage. For example, the high voltage power storage is a high voltage battery in a vehicle, and the low voltage power storage is a low voltage battery in a vehicle.

[0048] In an embodiment according to the second aspect of the present invention, one of the three-port isolated active bridge DC-DC power converters is designated as the master power converter. The control unit of the master power converter is configured to control the output current of the master power converter based on the output current set value. The remaining three-port isolated active bridge DC-DC power converters are designated as slave power converters. The control unit of each slave power converter is configured to control the output current of its respective slave power converter so as to match the output voltage of the master power converter. Alternatively, the control unit of each slave power converter is configured to control the output voltage of its respective slave power converter to be the reciprocal of the product of the number of three-port isolated active bridge DC-DC power converters in the three-port isolated active bridge DC-DC power converter system and the output voltage of the second system port.

[0049] When power is transmitted from the primary port to the secondary port, a control strategy is used by a three-port isolated active bridge DC-DC power converter provided by a power converter system. The primary port is the first primary port and / or the first system port. The secondary port is the second system port. The constraint of the control strategy is that the output voltage of the second system port is fixed. For example, the output voltage of the second system port is 380V. The control strategy is designed such that the output voltages of individual three-port isolated active bridge DC-DC power converters are balanced. To achieve this purpose, one of the three-port isolated active bridge DC-DC power converters provided by the power converter system is designated as the master power converter. The master power converter receives an output current set value. For example, the output current set value is 1A, or 2A, or 5A, or 10A. The control unit of the master power converter is configured such that the output current of the master power converter is controlled based on the output current set value and the output voltage of the second system port. The output current is the output current flowing through the secondary port of the master power converter. The slave power converters are connected in series to the secondary port of the master power converter via their secondary ports. While the master power converter is controlling its output current, the slave power converters control their output voltages to match the output voltage of the master power converter. The output voltage of each slave power converter is the output voltage of the secondary port of that respective slave power converter. The output voltage of the master power converter is the output voltage of the secondary port of the master power converter. Alternatively, the slave power converters control their output voltages to be the reciprocal of the product of the number of three-port isolated active bridge DC-DC power converters in the three-port isolated active bridge DC-DC power converter system and the output voltage of the second system port. In this last case, the voltage output of each slave power converter is given by the formula

[0050]

Number

[0051] Based on this, where nr pc is the number of three-port isolated active bridge DC-DC power converters of a three-port isolated active bridge DC-DC power converter system, and V HV is the output voltage of the second system port. In this way, the output voltages of the individual three-port isolated active bridge DC-DC power converters are balanced. The output voltages of the individual three-port isolated active bridge DC-DC power converters are controlled by controlling the phase shift between their primary-side ports and their secondary-side ports.

[0052] According to a third aspect of the present invention, the object is achieved by a multi-port isolated active bridge DC-DC power converter comprising a control unit, a primary side, and a secondary side.

[0053] The primary side includes a plurality of first primary-side ports, a second primary-side port, two primary-side switching elements for each first primary-side port, a primary-side converter inductance for each first primary-side port, and a primary-side transformer winding for each first primary-side port. Each pair of primary-side switching elements and their respective primary-side converter inductances are arranged to form a half-bridge arrangement for bidirectional power conversion between their respective first primary-side ports and the second primary-side port. The control unit is configured to control each pair of primary-side switching elements to convert power between their respective first primary-side ports and the second primary-side port. The primary-side switching elements are, for example, JFETs, IGBTs, GaN HEMTs, or MOSFETs.

[0054] The primary circuit is arranged to form a power converter between each first primary port and the second primary port for each first primary port. For example, when the voltage is stepped down between each first primary port and the second primary port, the primary side forms a step-down converter between each first primary port and the second primary port for each first primary port. As another example, when the voltage is stepped up between each first primary port and the second primary port, the primary side forms a boost converter between each first primary port and the second primary port for each first primary port. To improve the efficiency of the power converter, the first primary port and the second primary port are connected without insulation.

[0055] The secondary side includes a secondary port, two secondary switching elements, and a secondary transformer winding. In a preferred embodiment, the secondary side includes a single secondary transformer winding. The secondary transformer winding is magnetically coupled to the primary transformer winding. The primary switching element, the primary transformer winding, the two secondary switching elements, and the secondary transformer winding are arranged to form an isolated DC-DC converter between the primary side and the secondary side. In other words, the primary switching element, the primary transformer winding, the two secondary switching elements, and the secondary transformer winding are arranged to form an isolated DC-DC converter between a plurality of first primary ports and the secondary port. The control unit is further configured to control the primary switching element and the two secondary switching elements to convert power between the primary port and the secondary port. The secondary switching element is, for example, a JFET, an IGBT, a GaN HEMT, or a MOSFET.

[0056] The first primary port, the second primary port, and the secondary port each comprise a pair of terminals, which are used, for example, to connect to an external electrical circuit. For example, the second primary port is connected to a low-voltage bus, and this low-voltage bus connects a multi-port isolated active bridge DC-DC power converter to a low-voltage battery. For example, the secondary port is connected to a high-voltage bus, and this high-voltage bus connects a multi-port isolated active bridge DC-DC power converter to a high-voltage battery. For example, the first primary port is each connected to a power generation unit. The power generation unit is, for example, a solar power generation unit, or a fuel cell, or a wind turbine. For example, the multi-port isolated active bridge DC-DC power converter is used in a wind power plant. In this example, for example, a wind power generation unit such as a wind turbine is connected to each first primary port. In another example, the multi-port isolated active bridge DC-DC power converter is used in a solar power plant. In this example, for example, a solar power generation unit such as a solar panel is connected to each first primary port. In yet another example, the multi-port isolated active bridge DC-DC power converter is used in a fuel cell electric vehicle. In this example, a fuel cell is connected to each first primary port.

[0057] Therefore, the multi-port isolated active bridge DC-DC power converter provides an integrated architecture capable of bidirectional power conversion between the first primary port, the secondary port, and the second primary port. The bidirectional power flow is achieved by using primary-side switching elements and secondary-side switching elements configured to enable the bidirectional power flow. Further, the magnetic coupling of the primary-side transformer winding and the secondary-side transformer winding is arranged such that power flows between the primary side and the secondary side.

[0058] In an embodiment according to the third aspect of the present invention, each first primary port is an input power port arranged to be connected to an input power source. For example, the input power source is a fuel cell. As another example, the input power source is a photovoltaic power generation unit. Further, in the present embodiment, the second primary port is a low voltage port arranged to be connected to a low voltage power storage. For example, the low voltage power storage is a low voltage battery of a vehicle. Further, in the present embodiment, the secondary port is a high voltage port arranged to be connected to a high voltage power storage. For example, the high voltage power storage is a high voltage battery of a vehicle.

[0059] In an embodiment according to the third aspect of the present invention, each pair of primary side switching elements and their respective primary side converter inductances are arranged to form a buck converter or a boost converter.

[0060] In an embodiment according to the third aspect of the present invention, the primary side includes two additional primary side switching elements for each first primary port. Each set of four primary side switching elements is arranged to form a primary side full bridge for each first primary port.

[0061] The advantage of arranging two additional primary side switching elements for each first primary port and having each set of four primary side switching elements form a primary side full bridge for each first primary port is that, in some cases, the reactive current is minimized by using the phase shift between the set of four primary side switching elements and the two secondary side switching elements. A further advantage is that the full input voltage, i.e., the voltage supplied through each first primary port, is utilized in each primary side winding, reducing the current. In the case of a half bridge, only half of the input voltage, i.e., half of the voltage supplied through each first primary port, is available. Alternatively, the input voltage is the voltage supplied to the primary side through the transformer core.

[0062] In an embodiment according to a third aspect of the present invention, the secondary side includes two additional secondary side switching elements. The four secondary side switching elements are arranged to form a secondary side full bridge.

[0063] The advantage of arranging two additional secondary side switching elements such that the four secondary side switching elements form a secondary side full bridge is that the reactive current is minimized by using the phase shift between the four secondary side switching elements and the primary side switching element. A further advantage is that the full input voltage, i.e., the voltage supplied to the secondary side via the transformer core, is utilized at the secondary side port. In the case of a half bridge, only half of the input voltage, i.e., half of the voltage supplied to the secondary side via the transformer core, is available. Alternatively, the input voltage is the voltage supplied via the secondary side port.

[0064] In an embodiment according to a third aspect of the present invention, the multi-port isolated active bridge DC-DC power converter includes a blocking switch for each first primary side port. The control unit is further configured to open the blocking switch to prevent the flow of power between the primary side and the secondary side and to close the blocking switch to enable the flow of power between the primary side and the secondary side.

[0065] The primary side includes a first primary port and a second primary port, and the secondary port is provided by the secondary side. When power flow between the primary side and the secondary side is not required, it is desirable to prevent excitation of the transformer core, which is formed by a primary transformer winding and a secondary transformer winding. To prevent or minimize excitation of the transformer core, the multi-port isolated active bridge DC-DC power converter includes a blocking switch for each first primary port. The blocking switch is controlled by a control unit that opens and closes the blocking switch. When the blocking switch is closed, power flow between the primary side and the secondary side is enabled. This may be the case, for example, to enable power flow between the first primary port and the secondary port and / or between the second primary port and the secondary port. When the blocking switch is open, power flow between the primary side and the secondary side is prevented. This may be the case, for example, to exclusively enable power flow between the first primary port and the second primary port. In this case, the secondary side is bypassed, and the transformer core formed by the primary transformer winding and the secondary transformer winding is not excited or is minimally excited.

[0066] In an embodiment according to the third aspect of the present invention, the primary side includes a blocking switch.

[0067] In an embodiment according to the third aspect of the present invention, each blocking switch is connected in series to each primary transformer winding. By connecting each blocking switch in series to each primary transformer winding, the blocking switches are arranged such that when each one of the blocking switches is open, the flow of power between a single first primary port on the primary side and the secondary side is interrupted. Specifically, when the blocking switch is opened, the flow of power through each primary transformer winding and the secondary transformer winding is prevented. When the blocking switch is closed, the flow of power through each primary transformer winding and the secondary transformer winding is enabled. When all the blocking switches are open, the flow of power between the primary side and the secondary side is prevented. When all the blocking switches are closed, the flow of power through all the primary transformer windings and the secondary transformer windings is enabled.

[0068] In an embodiment according to the third aspect of the present invention, the secondary side further comprises a blocking switch. The control unit is further configured to open the blocking switch to prevent the flow of power between the primary side and the secondary side, and to close the blocking switch to enable the flow of power between the primary side and the secondary side. The primary side comprises a first primary port and a second primary port, and the secondary port is provided by the secondary side. When the flow of power between the primary side and the secondary side is not required, it is desirable to prevent or minimize the excitation of the transformer core, which is formed by the primary transformer winding and the secondary transformer winding. To prevent the excitation of the transformer core, the secondary side comprises a blocking switch. The blocking switch is controlled by a control unit, and this control unit opens and closes the blocking switch. When the blocking switch is closed, the flow of power between the primary side and the secondary side is enabled. This may be the case, for example, to enable the flow of power between the first primary port and the secondary port, and / or between the second primary port and the secondary port. When the blocking switch is open, the flow of power between the primary side and the secondary side is prevented. This may be the case, for example, when power flow is exclusively enabled between the first primary port and the second primary port. In this case, the secondary side is bypassed, and the transformer core formed by the primary transformer winding and the secondary transformer winding is not excited or is minimally excited.

[0069] In an embodiment according to the third aspect of the present invention, the blocking switch is connected in series with the secondary transformer winding. By connecting the blocking switch in series with the secondary transformer winding, the blocking switch is arranged to interrupt the flow of power between the secondary side and the primary side when the blocking switch is open. Specifically, when the blocking switch is opened, the flow of power through the secondary transformer winding and the primary transformer winding is prevented. When the blocking switch is closed, the flow of power through the primary transformer winding and the secondary transformer winding is enabled.

[0070] In an embodiment according to a third aspect of the present invention, each blocking switch includes two blocking switching elements. Each pair of blocking switching elements is connected in inverse series. By connecting two blocking switching elements in inverse series, power flow in both directions, i.e., from the primary side to the secondary side and from the secondary side to the primary side, can be prevented. To close the blocking switch, the control unit is configured to close the pair of blocking switching elements provided by each blocking switch. To open the blocking switch, the control unit is configured to open the pair of blocking switching elements provided by each blocking switch. The blocking switching element is, for example, a JFET, an IGBT, a GaN HEMT, or a MOSFET.

[0071] In an embodiment according to a third aspect of the present invention, the control unit is configured to control the primary side switching element and the secondary side switching element to generate a phase shift that determines power transfer between the primary side and the secondary side. When the blocking switching element is closed, power transfer between the primary side and the secondary side is enabled. In other words, power is transferred between one first primary port and a second primary port and the other secondary port. Power transfer to and from the secondary port is mainly controlled by the phase shift between the primary port, i.e., the first primary port and the second primary port, and the secondary port. The phase shift between the primary port and the secondary port is achieved by the control unit controlling the duty cycle of the primary side switching element and the duty cycle of the secondary side switching element.

[0072] In an embodiment according to a third aspect of the present invention, a multi-port isolated active bridge DC-DC power converter is configured to enable power flow from a first power port to a second power port. The first power port is one of a second primary port and a secondary port. The second power port is one of a second primary port and a secondary port. The first power port and the second power port are different.

[0073] In some cases, power flow between the two ports is exclusively desired.

[0074] For example, power flow from the secondary port to the second primary port is desired. For example, this is the case when power from the secondary port is required to supply power to a component connected to the second primary port. In this example, power is transmitted from the secondary port to the second primary port. In this example, the blocking switch is closed by the control unit, enabling power to flow between the primary side and the secondary side. Further, the primary side circuit, particularly the primary side switching element, and the secondary side circuit, particularly the secondary side switching element, are controlled by the control unit to convert power from the secondary port to the second primary port. In this case, the converter behaves as an isolated DC-DC power converter between the secondary port and the second primary port. Power transfer to the second primary port is mainly controlled by the phase shift between the secondary port and the second primary port. This phase shift is achieved by the control unit controlling the duty cycle of the primary side switching element and the duty cycle of the secondary side switching element. In this case, a positive phase shift between the secondary side switching element and the primary side switching element achieves power transfer from the secondary port to the second primary port. A positive phase shift between the secondary port and the second primary port means a negative phase shift between the second primary port and the secondary port.

[0075] In another example, power flow from the second primary port to the secondary port is enabled.

[0076] In an embodiment according to a third aspect of the present invention, the multi-port isolated active bridge DC-DC power converter is configured to allow power to flow from each of the first primary power ports to the first power port. The first power port is one of the second primary port and the secondary port.

[0077] In some cases, power flow between the first primary port and another port is exclusively desired.

[0078] For example, power flow from each of the first primary ports to the second primary port is desired. For example, this is the case when all the power flowing into the first primary port is required to supply power to components connected to the second primary port. In this example, the blocking switch is opened by the control unit to prevent any power flow between the primary side and the secondary side. Further, the primary side circuit, particularly the primary side switching element, is controlled by the control unit to convert power from the first primary port to the second primary port. In this case, the converter behaves as, for example, a buck converter or a boost converter. Specifically, the duty cycle of the primary side switching element determines the power transfer from each of the first primary ports to the second primary port.

[0079] In another example, power flow from each of the first primary ports to the secondary port is enabled.

[0080] In an embodiment according to a third aspect of the present invention, the multi-port isolated active bridge DC-DC power converter is configured to allow power to flow from each of the first primary power ports and from the first power port to the second power port. The first power port is one of the second primary port and the secondary port. The second power port is one of the second primary port and the secondary port. The first power port and the second power port are different.

[0081] In some cases, power flow from each of the first primary ports and the power port to another power port is desired.

[0082] For example, power flow from each of the first primary ports and the second primary port to the secondary port is desired. In this case, the power flowing into each of the first primary ports and the power flowing into the second primary port can be transmitted to the secondary port and accumulated, for example, in a power storage, such as a battery. In another example, this power can be used to supply power to components connected to the secondary port. In this embodiment, the blocking switch is closed by the control unit to enable power to flow between the primary side and the secondary side. Further, the primary side circuit, particularly the primary side switching element, and the secondary side circuit, particularly the secondary side switching element, are controlled by the control unit to convert power from each of the first primary ports and the second primary port to the secondary port. In this case, the converter behaves as an isolated DC-DC power converter between the primary side port and the secondary side port. Power transmission to the secondary port is mainly controlled by the phase shift between each of the first primary ports, the second primary port, and the secondary port. This phase shift is achieved by the control unit controlling the duty cycle of the primary side switching element and the duty cycle of the secondary side switching element. In this case, a positive phase shift between the primary side switching element and the secondary side switching element achieves power transmission from the first primary port and the second primary port to the secondary port.

[0083] As another example, power flow from each of the first primary ports and the secondary port to the second primary port is desired. For example, this is the case where power from each of the secondary port and the first primary ports is required to supply power to a component connected to the second primary port. In this example, power is transferred from the secondary port and the first primary ports to the second primary port. In this example, the blocking switch is closed by the control unit, enabling power to flow between the primary side and the secondary side. Further, the primary side circuit, particularly the primary side switching element, and the secondary side circuit, particularly the secondary side switching element, are controlled by the control unit to convert power from the secondary port to the second primary port. In this case, the converter behaves as an isolated DC-DC power converter between the secondary port and the second primary port. Power transfer to the second primary port is mainly controlled by the phase shift between the secondary port and the second primary port. This phase shift is achieved by the control unit controlling the duty cycle of the primary side switching element and the duty cycle of the secondary side switching element. In this case, a positive phase shift between the secondary side switching element and the primary side switching element achieves power transfer from the secondary port to the second primary port. A positive phase shift between the secondary port and the second primary port means a negative phase shift between the second primary port and the secondary port. Further, the primary side circuit, particularly the primary side switching element, is controlled by the control unit to convert power from each of the first primary ports to the second primary port. In this case, the converter additionally behaves as a buck converter or a boost converter. Specifically, the duty cycle of the primary side switching element determines the power transfer from each of the first primary ports to the second primary port.

[0084] In an embodiment according to a third aspect of the present invention, the multi-port isolated active bridge DC-DC power converter is configured to enable the flow of power from the first port to each of the first primary ports. The first power port is one of the second primary port and the secondary port.

[0085] In an embodiment according to a third aspect of the present invention, the multi-port isolated active bridge DC-DC power converter is configured to enable the flow of power from the first power port to each of the first primary ports and to the second power port. The first power port is one of the second primary port and the secondary port. The second power port is one of the second primary port and the secondary port. The first power port and the second power port are different.

[0086] In some cases, the flow of power from a single port to each of the first primary ports and to another power port is desired.

[0087] For example, power flow from the secondary port to each of the first primary port and the second primary port is desired. For example, this is the case when power from the secondary port is required to supply components connected to the first primary port and components connected to the second primary port. In this example, power is transferred from the secondary port to the first primary port and the second primary port. In this example, the blocking switch is closed by the control unit, enabling power to flow between the primary side and the secondary side. Further, the primary side circuit, particularly the primary side switching element, and the secondary side circuit, particularly the secondary side switching element, are controlled by the control unit to convert power from the secondary port to the first primary port and the second primary port. In this case, the converter behaves as an isolated DC-DC power converter between the secondary side and the primary side. Power transfer to the first primary port and the second primary port is mainly controlled by the phase shift between the secondary port and the primary port. This phase shift is achieved by the control unit controlling the duty cycle of the primary side switching element and the duty cycle of the secondary side switching element. In this case, a positive phase shift between the secondary side switching element and the primary side switching element achieves power transfer from the secondary port to the first primary port and the second primary port. A positive phase shift between the secondary port and the primary port means a negative phase shift between the primary port and the secondary port.

[0088] As another example, power flow from the second primary port to the first primary port and the secondary port is enabled.

[0089] According to a fourth aspect of the present invention, the object is achieved by a multi-port isolated active bridge DC-DC power converter system comprising a plurality of multi-port isolated active bridge DC-DC power converters according to the third aspect of the present invention, a first system port, and a second system port. The plurality of multi-port isolated active bridge DC-DC power converters are coupled in parallel via their second primary ports so as to form the first system port. The plurality of multi-port isolated active bridge DC-DC power converters are coupled in series via their secondary ports so as to form the second system port.

[0090] To expand the power converter for more power inputs, the multi-port isolated active bridge DC-DC power converter system comprises a plurality of multi-port isolated active bridge DC-DC power converters. Thus, a plurality of first primary ports are available to the multi-port isolated active bridge DC-DC power converter system. Thus, the power converter system is configured to be connected to, for example, a plurality of power generation units. The power generation units are, for example, photovoltaic power generation units, or fuel cells, or wind turbines.

[0091] It is an object to provide a power converter system having a single secondary port and a single second primary port. To achieve this object, the secondary ports of a multi-port isolated active bridge DC-DC power converter are connected in series. This forms a second system port. By connecting the secondary ports in series, it is possible to reduce the voltage gain required between the primary side and the secondary side. Further, the voltage ratings of the semiconductors used in the circuit of the multi-port isolated active bridge DC-DC power converter system, namely, the primary side switching element, the secondary side switching element, and the blocking switch, are reduced. This improves the reliability of the system and reduces its cost. Further, in this architecture, a high dynamic output voltage range of the second system port is achieved. For example, when the power input from any of the first primary ports of the multi-port isolated active bridge DC-DC power converter provided by the power converter system is reduced, the output voltage, i.e., the voltage of the secondary port, is compensated. For example, when the solar radiation amount of the solar power generation unit connected to the first primary port is reduced, the power input from the first primary port is reduced. In one example, the reduced input power is compensated by transmitting power from the first primary port to the first system port instead of the second system port. In an alternative example, the reduced input power is compensated by additionally transmitting power from the first system port to the second system port. In a further alternative example, the reduced input power is compensated by additionally transmitting power from the second system port to the first system port.

[0092] In an embodiment according to a fourth aspect of the present invention, the first system port is a high voltage port arranged to be connected to a high voltage power storage, and the second system port is a low voltage port arranged to be connected to a low voltage power storage. For example, the high voltage power storage is a high voltage battery in a vehicle, and the low voltage power storage is a low voltage battery in a vehicle.

[0093] In an embodiment according to a fourth aspect of the present invention, one of the multi-port isolated active bridge DC-DC power converters is designated as a master power converter. The control unit of the master power converter is configured to control the output current of the master power converter based on an output current set value. The remaining multi-port isolated active bridge DC-DC power converters are designated as slave power converters. The control unit of each slave power converter is configured to control the output voltage of its respective slave power converter to match the output voltage of the master power converter. Alternatively, the control unit of each slave power converter is configured to control the output voltage of its respective slave power converter to be the reciprocal of the product of the number of multi-port isolated active bridge DC-DC power converters in the multi-port isolated active bridge DC-DC power converter system and the output voltage of the first system port.

[0094] When power is transmitted from the primary port to the secondary port, a control strategy is used by a multi-port isolated active bridge DC-DC power converter provided by a power converter system. The primary port is the first primary port and / or the first system port. The secondary port is the second system port. The constraint of the control strategy is that the output voltage of the second system port is fixed. For example, the output voltage of the second system port is 380V. The control strategy is designed such that the output voltages of individual multi-port isolated active bridge DC-DC power converters are balanced. To achieve this purpose, one of the multi-port isolated active bridge DC-DC power converters is designated as the master power converter. The master power converter receives an output current set value. For example, the output current set value is 1A, or 2A, or 5A, or 10A. The control unit of the master power converter is configured such that the output current of the master power converter is controlled based on the output current set value and the output voltage of the second system port. The output current is the output current flowing through the secondary port of the master power converter. The slave power converters are connected in series to the secondary port of the master power converter via their secondary ports. While the master power converter controls its output current, the slave power converters control their output voltages to match the output voltage of the master power converter. The output voltage of each slave power converter is the output voltage of the secondary port of each respective slave power converter. The output voltage of the master power converter is the output voltage of the secondary port of the master power converter. Alternatively, the slave power converters control their output voltages to be the reciprocal of the product of the number of multi-port isolated active bridge DC-DC power converters in the multi-port isolated active bridge DC-DC power converter system and the output voltage of the second system port. In this last case, the voltage output of each slave power converter is given by the formula

[0095]

Number

[0096] Based on this, where nr pc is the number of multi-port isolated active bridge DC-DC power converters of a three-port isolated active bridge DC-DC power converter system, and V HV is the output voltage of the second system port. In this way, the output voltages of the individual multi-port isolated active bridge DC-DC power converters are balanced. The output voltages of the individual multi-port isolated active bridge DC-DC power converters are controlled by controlling the phase shift between their primary-side ports and their secondary-side ports.

[0097] According to a fifth aspect of the present invention, the object is achieved by a solar power assembly comprising a plurality of solar power generation units and a power converter system. The power converter system is either a three-port isolated active bridge DC-DC power converter system according to the second aspect of the present invention or a multi-port isolated active bridge DC-DC power converter system according to the fourth aspect of the present invention. Each solar power generation unit of the plurality of solar power generation units is connected to a first primary-side port of the power converter system.

[0098] The power converter system includes a plurality of first primary ports, for example, 2, or 4, or 10, or 24 first primary ports. The first primary ports are constituted by power converters provided by the power converter system. For example, the 24 first primary ports of the power converter system are constituted by 12 multi-port isolated active bridge DC-DC power converter systems each having 2 first primary ports. Each first primary port is configured to be connected to a power generation unit. For example, the power generation unit is a solar power generation unit, or a fuel cell, or a wind turbine. According to the fifth aspect of the present invention, the solar power generation unit is a solar power generation unit. For example, the solar power generation unit is a solar panel, or a strip of solar cells. For example, the solar power generation unit is configured to be disposed on a surface such as the body of a vehicle. The power generated by the individual solar power generation units is converted for further use. To achieve this goal, each solar power generation unit is electrically connected to the first primary port of the power converter system. The power converter system is configured to convert the input power generated by the solar power generation unit into output power and flow out from its first system port and / or its second system port.

[0099] According to the sixth aspect of the present invention, the object is achieved by a vehicle including a body, a solar power assembly according to the fifth aspect of the present invention, a low voltage battery, and a high voltage battery. The plurality of solar power generation units of the solar power assembly are mechanically attached to the body. The low voltage battery is connected to the first system port of the power converter system of the solar power assembly, and the high voltage battery is connected to the second system port of the power converter system of the solar power assembly.

[0100] The vehicle is equipped with a low-voltage battery, which is connected to a low-voltage bus, and the low-voltage bus supplies power to specific electrical components of the vehicle. The electrical components powered by the low-voltage battery include, for example, the electric windows and lights of the vehicle. The vehicle further includes a high-voltage battery, which is connected to a high-voltage bus. The high-voltage bus supplies power to specific electrical components of the vehicle. The electrical components powered by the high-voltage bus include, for example, the HVAC system and the electric motor or motors for propelling the vehicle. The low-voltage battery is electrically connected to a first system port of the power converter system via the low-voltage bus. This enables power to flow between the low-voltage battery. The high-voltage battery is electrically connected to a second system port of the power converter system via the high-voltage bus. This enables power to flow between the high-voltage battery.

[0101] By mechanically attaching a plurality of solar power generation units of a solar power assembly to the vehicle body and electrically connecting them to a power converter system, the solar power generation units generate power when they are exposed to sunlight. The power generated by the solar power generation units flows through the first primary-side port while the solar power generation units are electrically connected to the power converter system. The power converter system is configured to convert the power generated by the solar power generation units so that it can be used by the vehicle, particularly its low-voltage and high-voltage batteries.

[0102] In this way, a semi-autonomous vehicle is provided, which is configured to supply power to its electrical components using the power generated by its solar power generation units.

[0103] The present invention will be described below with reference to the drawings. These drawings function as examples for explaining the present invention and should not be construed as defining the scope of the claims. In different drawings, similar features are denoted by similar reference numerals.

Brief Description of the Drawings

[0104]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6a

Figure 6b

Figure 7

Figure 8

Modes for Carrying Out the Invention

[0105] Figures 1, 2, and 3 schematically show a three-port isolated active bridge DC-DC power converter (101) according to the first, second, and third embodiments of the first aspect of the present invention. In this figure, the three-port isolated active bridge DC-DC power converter (101) includes a control unit (102), a primary side (103), and a secondary side (104).

[0106] The primary side includes a first primary port (105), a second primary port (106), two primary side switching elements (107a, 107b), a primary side converter inductance (108), a primary side transformer winding (109), and a blocking switch (110). The two primary side switching elements (107a, 107b) and the primary side converter inductance (108) are arranged to form a step-down converter for converting power between the first primary port (105) and the second primary port (106). The control unit (102) is configured to control the two primary side switching elements (107a, 107b) to convert power between the first primary port (105) and the second primary port (106).

[0107] The secondary side (104) includes a secondary port (111), two secondary switching elements (112a, 112b), and a secondary transformer winding (113) magnetically coupled to the primary transformer winding (109). The two primary switching elements (107a, 107b), the primary transformer winding (109), the two secondary switching elements (112a, 112b), and the secondary transformer winding (113) are arranged to form an isolated DC-DC converter between the primary ports (105, 106) and the secondary port (111). The control unit (102) is configured to open the blocking switch (110) to prevent the flow of power between the primary side (103) and the secondary side (104), and to close the blocking switch (110) to enable the flow of power between the primary side (103) and the secondary side (104). The control unit (102) is further configured to control the two primary switching elements (107a, 107b) and the two secondary switching elements (112a, 112b) to convert power between the primary ports (105, 106) and the secondary port (111).

[0108] The blocking switch (110) includes two blocking switching elements (114a, 114b), and the two blocking switching elements (114a, 114b) are connected in reverse series. The two blocking switching elements (114a, 114b) are connected in series with the primary transformer winding (109). The blocking switching elements (114a, 114b) are arranged to block the flow of power between the primary side (103) and the secondary side (104) when they are open. When the blocking switching elements (114a, 114b) are opened, the three-port isolated active bridge DC-DC power converter (101) is configured to prevent or minimize the flow of power from the first primary port (105) to the second primary port (106).

[0109] The blocking switching elements (114a, 114b) are arranged to enable the flow of power between the primary side (103) and the secondary side (104) when they are closed. When the blocking switching elements (114a, 114b) are closed, the three-port isolated active bridge DC-DC power converter (101) is configured to enable the flow of power from the first primary port (105) to the secondary port (111). Further, when the blocking switching elements (114a, 114b) are closed, the three-port isolated active bridge DC-DC power converter (101) is configured to enable the flow of power from the secondary port (111) to the second primary port (106). Further, when the blocking switching elements (114a, 114b) are closed, the three-port isolated active bridge DC-DC power converter (101) is configured to enable the flow of power from the second primary port (106) to the secondary port (111). Further, when the blocking switching elements (114a, 114b) are closed, the three-port isolated active bridge DC-DC power converter (101) is configured to enable the flow of power from the second primary port (106) and the first primary port (105) to the secondary port (111). Further, when the blocking switching elements (114a, 114b) are closed, the three-port isolated active bridge DC-DC power converter (101) is configured to enable the flow of power from the secondary port (111) and the first primary port (105) to the second primary port (106). Further, when the blocking switching elements (114a, 114b) are closed, the three-port isolated active bridge DC-DC power converter (101) is configured to enable the flow of power from the first primary port (105) to the second primary port (106) and the secondary port (111). Further, the three-port isolated active bridge DC-DC power converter (101) is configured to enable the flow of power from the second primary port (106) and / or the secondary port (111) to the first primary port (105).

[0110] The power flow in a three-port isolated active bridge DC-DC power converter (101) is controlled by a control unit (102) controlling the switching of primary-side switching elements (107a, 107b) and secondary-side switching elements (112a, 112b). When power is converted from a first primary port (105) to a second primary port (106), the three-port isolated active bridge DC-DC power converter (101) functions as a step-down converter between the first primary port (105) and the second primary port (106). Additionally, when power is converted between the primary side (103) and the secondary side (104), the three-port isolated active bridge DC-DC power converter (101) functions as an isolated DC-DC power converter between the primary side (103) and the secondary side (104). Specifically, the three-port isolated active bridge DC-DC power converter (101) is configured to enable bidirectional power flow between all its ports, particularly between the second primary port (106) and the secondary port (111), and between the secondary port (111) and the first primary port (105). To enable this bidirectional power flow, the control unit (102) is configured to control the primary-side switching elements (107a, 107b) and the secondary-side switching elements (112a, 112b) to generate a phase shift that determines the power transfer between the primary side (103) and the secondary side (104). In particular, a positive phase shift between the primary ports (105, 106) and the secondary port (111) results in power flow to the secondary port (111). A negative phase shift between the primary ports (105, 106) and the secondary port (111) results in power flow to the second primary port (106) and / or the first primary port (105).

[0111] FIG. 2 schematically shows a three-port isolated active bridge DC-DC power converter (101) according to a second embodiment of the first aspect of the present invention. Compared with the first embodiment of the first aspect of the present invention schematically shown in FIG. 1, the primary side (103) includes two additional primary side switching elements (107c, 107d). The four primary side switching elements (107a, 107b, 107c, 107d) are configured to form a primary side full bridge. The advantage of adding the two additional primary side switching elements (107c, 107d) and having the four primary side switching elements (107a, 107b, 107c, 107d) form a primary side full bridge is that it is possible to minimize the reactive current by using the phase shift between the four primary side switching elements (107a, 107b, 107c, 107d) and the two secondary side switching elements (112a, 112b). A further advantage is that the full input voltage, i.e., the voltage supplied via the first primary port (105) and / or the second primary port (106), is available across the primary winding (109). In the case of a half bridge, only half of the input voltage is available.

[0112] In a three-port isolated active bridge DC-DC power converter (101), the power flow is controlled by a control unit (102) controlling the switching of primary side switching elements (107a, 107b, 107c, 107d) and secondary side switching elements (112a, 112b). When power is converted from a first primary port (105) to a second primary port (106), the three-port isolated active bridge DC-DC power converter (101) functions as a step-down converter between the first primary port (105) and the second primary port (106). Additionally, when power is converted between the primary side (103) and the secondary side (104), the three-port isolated active bridge DC-DC power converter (101) functions as an isolated DC-DC power converter between the primary side (103) and the secondary side (104). Specifically, the three-port isolated active bridge DC-DC power converter (101) is configured to enable bidirectional power flow between all its ports, particularly between the second primary port (106) and the secondary port (111). To enable this bidirectional power flow, the control unit (102) is configured to control the primary side switching elements (107a, 107b, 107c, 107d) and the secondary side switching elements (112a, 112b) to generate a phase shift that determines the power transfer between the primary side (103) and the secondary side (104). In particular, a positive phase shift between the primary ports (105, 106) and the secondary port (111) results in power flow to the secondary port (111). A negative phase shift between the primary ports (105, 106) and the secondary port (111) results in power flow to the second primary port (106) and / or the first primary port (105).

[0113] FIG. 3 schematically shows a three-port isolated active bridge DC-DC power converter (101) according to a third embodiment of the first aspect of the present invention. Compared with the first embodiment of the first aspect of the present invention schematically shown in FIG. 1, the secondary side (104) includes two additional secondary side switching elements (112c, 112d). The four secondary side switching elements (112a, 112b, 112c, 112d) are configured to form a secondary side full bridge.

[0114] The advantage of adding two additional secondary side switching elements (112c, 112d) such that the four secondary side switching elements (112a, 112b, 112c, 112d) form a secondary side full bridge is that the reactive current can be minimized by using the phase shift between the four secondary side switching elements (112a, 112b, 112c, 112d) and the primary side switching elements (107a, 107b). A further advantage is that the full input voltage, i.e., the voltage supplied to the secondary side (104) via the transformer core, is available at the secondary side port (111). In the case of a half bridge, only half of the input voltage, i.e., half of the voltage supplied to the secondary side (104) via the transformer core, is available.

[0115] The power flow in a three-port isolated active bridge DC-DC power converter (101) is controlled by a control unit (102) controlling the switching of primary-side switching elements (107a, 107b) and secondary-side switching elements (112a, 112b, 112c, 112d). When power is converted from a first primary port (105) to a second primary port (106), the three-port isolated active bridge DC-DC power converter (101) functions as a step-down converter between the first primary port (105) and the second primary port (106). Additionally, when power is converted between the primary side (103) and the secondary side (104), the three-port isolated active bridge DC-DC power converter (101) functions as an isolated DC-DC power converter between the primary side (103) and the secondary side (104). Specifically, the three-port isolated active bridge DC-DC power converter (101) is configured to enable bidirectional power flow between all its ports, particularly between the second primary port (106) and the secondary port (111). To enable this bidirectional power flow, the control unit (102) is configured to control the primary-side switching elements (107a, 107b) and the secondary-side switching elements (112a, 112b, 112c, 112d) to generate a phase shift that determines the power transfer between the primary side (103) and the secondary side (104). In particular, a positive phase shift between the primary ports (105, 106) and the secondary port (111) results in power flowing to the secondary port (111). A negative phase shift between the primary ports (105, 106) and the secondary port (111) results in power flowing to the second primary port (106) and / or the first primary port (105).

[0116] FIG. 4 schematically shows a multi-port isolated active bridge DC-DC power converter (401) according to a first embodiment of a third aspect of the present invention. In this figure, the multi-port isolated active bridge DC-DC power converter (401) includes a control unit (402), a primary side (403), and a secondary side (404).

[0117] The primary side (403) includes two first primary ports (405a, 405b) and a second primary port (406). The primary side (403) further includes four primary switching elements (407a, 407b, 407c, 407d) and two primary converter inductances (408a, 408b). Two primary switching elements (407a, 407b) and the first primary converter inductance (408a) are associated with the first first primary port (405a) to form a buck converter for converting power between the first first primary port (405a) and the second primary port (406). The other two primary switching elements (407c, 407d) and the second primary converter inductance (408b) are associated with the second first primary port (405b) to form a buck converter for converting power between the second first primary port (405b) and the second primary port (406). The control unit (402) is configured to control a first pair of primary switching elements (407a, 407b) for converting power between the first first primary port (405a) and the second primary port (406). The control unit (402) is further configured to control a second pair of primary switching elements (407c, 407d) for converting power between the second first primary port (405b) and the second primary port (406). The primary side (403) further includes two primary transformer windings (409a, 409b), the first primary transformer winding (409a) is associated with the first first primary port (405a), and the second primary transformer winding (409b) is associated with the second first primary port (405b).

[0118] The secondary side (404) includes a secondary port (411), two secondary switching elements (412a, 412c), and primary transformer windings (409a, 409b), that is, a single secondary transformer winding (413) magnetically coupled to each of the primary transformer windings (409a, 409b). The primary switching elements (407a, 407b, 407c, 407d), the primary transformer windings (409a, 409b), the two secondary switching elements (412a, 412b), and the secondary transformer winding (413) are arranged to form an isolated DC-DC converter between the primary ports (405a, 405b, 406) and the secondary port (411). The control unit is further configured to control the primary switching elements (407a, 407b, 407c, 407d) and the two secondary switching elements (412a, 412b) for power conversion between the primary port (405a, 405b, 406) and the secondary port (411).

[0119] The primary side (403) further includes two blocking switches (410a, 410b). The first blocking switch (410a) is associated with the first first primary port (405a), and the second blocking switch (410b) is associated with the second first primary port (405b). The control unit (402) is further configured to open the blocking switches (410a, 410b) to prevent power flow between the primary side (403) and the secondary side (404), and to close the blocking switches (410a, 410b) to enable power flow between the primary side (403) and the secondary side (404). Each blocking switch (410a, 410b) includes two blocking switching elements (414a, 414b, 414c, 414d). The blocking switching elements (414a, 414b, 414c, 414d) are connected in inverse series. The first pair of blocking switching elements (414a, 414b) is connected in series to the first primary transformer winding (409a). The second pair of blocking switching elements (414c, 414d) is connected in series to the second primary transformer winding (409b).

[0120] The blocking switching elements (414a, 414b, 414c, 414d) are arranged to block the flow of power between the primary side (403) and the secondary side (404) when they are open. The blocking switching elements (414a, 414b, 414c, 414d) are arranged to enable the flow of power between the primary side (403) and the secondary side (404) when they are closed.

[0121] When the blocking switching elements (414a, 414b, 414c, 414d) are closed, the multi-port isolated active bridge DC-DC power converter (401) is configured to allow power to flow from the first primary ports (405a, 405b) to the secondary port (411). Further, when the blocking switching elements (414a, 414b, 414c, 414d) are closed, the multi-port isolated active bridge DC-DC power converter (401) is configured to allow power to flow from the secondary port (411) to the second primary port (406). Further, when the blocking switching elements (414a, 414b, 414c, 414d) are closed, the multi-port isolated active bridge DC-DC power converter (401) is configured to allow power to flow from the second primary port (406) to the secondary port (411). Further, when the blocking switching elements (414a, 414b, 414c, 414d) are closed, the multi-port isolated active bridge DC-DC power converter (401) is configured to allow power to flow from the second primary port (406) and the first primary ports (405a, 405b) to the secondary port (411). Further, when the blocking switching elements (414a, 414b, 414c, 414d) are closed, the multi-port isolated active bridge DC-DC power converter (401) is configured to allow power to flow from the secondary port (411) and the first primary port (405) to the second primary port (406). Further, when the blocking switching elements (414a, 414b, 414c, 414d) are closed, the multi-port isolated active bridge DC-DC power converter (401) is configured to allow power to flow from the first primary ports (405a, 405b) to the second primary port (406) and the secondary port (411). Further, the multi-port isolated active bridge DC-DC power converter (401) is configured to allow power to flow from the second primary port (406) and / or the secondary port (411) to the first primary ports (405a, 405b).

[0122] In the multi-port isolated active bridge DC-DC power converter (401), the flow of power is controlled by the control unit (402) controlling the switching of the primary side switching elements (407a, 407b, 407c, 407d) and the secondary side switching elements (412a, 412b). When power is converted from the first primary side ports (405a, 405b) to the second primary side port (406), the multi-port isolated active bridge DC-DC power converter (401) functions as a step-down converter between the first primary side ports (405a, 405b) and the second primary side port (406). Additionally, when power is converted between the primary side (403) and the secondary side (404), the multi-port isolated active bridge DC-DC power converter (401) functions as an isolated DC-DC power converter between the primary side (403) and the secondary side (404). Specifically, the multi-port isolated active bridge DC-DC power converter (401) is configured to enable bidirectional power flow between all of its ports, particularly between the second primary side port (406) and the secondary side port (411). To enable this bidirectional power flow, the control unit (402) is configured to control the primary side switching elements (407a, 407b, 407c, 407d) and the secondary side switching elements (412a, 412b) to generate a phase shift that determines the power transfer between the primary side (403) and the secondary side (404). In particular, a positive phase shift between the primary side ports (405a, 405b, 406) and the secondary side port (411) results in power flowing to the secondary side port (411). A negative phase shift between the primary side ports (405a, 405b, 406) and the secondary side port (411) results in power flowing to the second primary side port (406) and / or the first primary side ports (405a, 405b).

[0123] FIG. 5 schematically shows a multi-port port isolated active bridge DC-DC power converter according to a second embodiment of the third aspect of the present invention.

[0124] Compared with the first embodiment of the third aspect of the present invention schematically shown in FIG. 4, the primary side (403) includes four additional primary side switching elements (407e, 407f, 407g, 407h). The first set of four primary side switching elements (407a, 407b, 407e, 407f) is arranged to form a first primary side full bridge associated with the first first primary side port (405a). The second set of four primary side switching elements (407c, 407d, 407g, 407h) is arranged to form a second primary side full bridge associated with the second first primary side port (405b). Additionally, the secondary side (404) includes two additional secondary side switching elements (412c, 412d). The four secondary side switching elements (412a, 412b, 412c, 412d) are arranged to form a secondary side full bridge.

[0125] The advantage of forming the primary side full bridge and the secondary side full bridge is that it becomes possible to minimize the reactive current by using the phase shift between the eight primary side switching elements (407a, 407b, 407c, 407d, 407e, 407f, 407g, 407h) and the secondary side switching elements (412a, 412b, 412c, 412d). A further advantage is that the full input voltage, i.e., the voltage supplied via the first first primary side port (405a) and the second first primary side port (405b), is available in the first primary winding (409a) and the second primary winding (409b), respectively. In the case of a half bridge, only half of the input voltage, i.e., half of the voltage supplied via the first primary side ports (405a, 405b), is available. A further advantage is that the full voltage supplied to the secondary side (404) via the transformer core is available at the secondary side port (411). In the case of a half bridge, only half of the voltage supplied to the secondary side (404) via the transformer core is available.

[0126] Figure 6a schematically shows a three-port isolated active bridge DC-DC power converter system (601) according to an embodiment of a second aspect of the present invention. In this figure, the three-port isolated active bridge DC-DC power converter system (601) includes four three-port isolated active bridge DC-DC power converters (101a, 101b, 101c, 101d) according to a first aspect of the present invention, a first system port (602), and a second system port (603).

[0127] The four three-port isolated active bridge DC-DC power converters (101a, 101b, 101c, 101d) are coupled in series via their secondary ports (111a, 111b, 111c, 111d) to form the second system port (603). Additionally, the four three-port isolated active bridge DC-DC power converters (101a, 101b, 101c, 101d) are coupled in parallel via their second primary ports (106a, 106b, 106c, 106d) to form the first system port (602).

[0128] The three-port isolated active bridge DC-DC power converter system (601) is configured such that four power generation units are connected to its four first primary ports (105a, 105b, 105c, 105d). Further, the three-port isolated active bridge DC-DC power converter system (601) includes a single first system port (602) and a single second system port (603). The first system port (602) is arranged to be connected to a low-voltage bus of a vehicle. The second system port (603) is arranged to be connected to a high-voltage bus of a vehicle.

[0129] FIG. 6b schematically shows a multi-port isolated active bridge DC-DC power converter system (604) according to an embodiment of a fourth aspect of the present invention. In this figure, the multi-port isolated active bridge DC-DC power converter system (604) includes four multi-port isolated active bridge DC-DC power converters (401a, 401b, 401c, 401d) according to a third aspect of the present invention, a first system port (602), and a second system port (603).

[0130] The four multi-port isolated active bridge DC-DC power converters (401a, 401b, 401c, 401d) are coupled in series via their secondary ports (411a, 411b, 411c, 411d) to form the second system port (603). Additionally, the four multi-port isolated active bridge DC-DC power converters (401a, 401b, 401c, 401d) are coupled in parallel via their second primary ports (406a, 406b, 406c, 406d) to form the first system port (602).

[0131] The multi-port isolated active bridge DC-DC power converter system (604) is configured such that eight power generation units are connected to its eight first primary ports (405a to 405h). Further, the multi-port isolated active bridge DC-DC power converter system (604) includes a single first system port (602) and a single second system port (603). The first system port (602) is arranged to be connected to a low voltage bus of the vehicle. The second system port (603) is arranged to be connected to a high voltage bus of the vehicle.

[0132] FIG. 7 schematically shows a solar power assembly (701) according to an embodiment of a fifth aspect of the present invention. In this figure, the solar power assembly (701) includes 28 solar power generation units ( 702 aa- 702nb) and a multi-port isolated active bridge DC-DC power converter system (604) according to a fourth aspect of the present invention. Fourteen multi-port isolated active bridge DC-DC power converters (401a to 401n) provided by the multi-port isolated active bridge DC-DC power converter system (604) are each connected to two solar power generation units ( 702 aa- 702 nb).

[0133] One of the multi-port isolated active bridge DC-DC power converters (401a to 401n) provided by the multi-port isolated active bridge DC-DC power converter system (604) is designated as a master power converter. The control unit of the master power converter is configured to control the output current of the master power converter based on an output power set value. For example, the first multi-port isolated active bridge DC-DC power converter (401a) is designated as the master power converter. The remaining multi-port isolated active bridge DC-DC power converters (401b to 401n) are designated as slave power converters. The control unit of each slave power converter (401b to 401n) is configured to control the output voltage of each of its slave power converters (401b to 401n) to match the output voltage of the master power converter (401a). Alternatively, the control unit of each slave power converter is configured to control the output voltage of each of its slave power converters to be the reciprocal of the product of the number of multi-port isolated active bridge DC-DC power converters (401b to 401n) in the multi-port isolated active bridge DC-DC power converter system (604) and the output voltage of the first system port (602).

[0134] A multi-port isolated active bridge DC-DC power converter system (604) provided by a solar power assembly includes a single first system port (602) and a single second system port (603). The first system port (602) is arranged to be connected to a low-voltage bus of a vehicle. The second system port (603) is arranged to be connected to a high-voltage bus of the vehicle.

[0135] FIG. 8 schematically shows a vehicle (801) according to an embodiment of a sixth aspect of the present invention. In this figure, the vehicle (801) includes a body (802), a solar power assembly (701) according to a fifth aspect of the present invention, a low-voltage battery (803), and a high-voltage battery (804).

[0136] The solar power generation units (702aa to 702nb) of the solar power assembly are mechanically attached to the body (802). The low-voltage battery (803) is connected to the first system port (602) of the power converter system (601) of the solar power assembly (701), and the high-voltage battery (803) is connected to the second system port (603) of the multi-port isolated active bridge DC-DC power converter system (604) of the solar power assembly (701).

[0137] The vehicle is equipped with a low-voltage battery (803), and the low-voltage battery (803) is connected to a low-voltage bus, which supplies power to the low-voltage electrical components of the vehicle (801). The vehicle further includes a high-voltage battery (804), and the high-voltage battery (804) is connected to a high-voltage bus, which supplies power to the high-voltage electrical components of the vehicle (801). The low-voltage battery (803) is electrically connected to a first system port (602) of a multi-port isolated active bridge DC-DC power converter system (604) via the low-voltage bus. This enables power to flow between the low-voltage battery (803). The high-voltage battery (804) is electrically connected to a second system port (603) of the multi-port isolated active bridge DC-DC power converter system (604) via the high-voltage bus. This enables power to flow between the high-voltage battery (804).

[0138] By mechanically attaching the photovoltaic units (702aa - 702nb) of the photovoltaic assembly (701) to the body (802) of the vehicle (801), the photovoltaic units (702aa - 702nb) generate power when they are exposed to sunlight. The power generated by the photovoltaic units (702aa - 702nb) flows through their respective first primary-side ports (405a - 405h) with each one of the photovoltaic units (702aa - 702nb) being electrically connected to a multi-port isolated active bridge DC-DC power converter system (604). The multi-port isolated active bridge DC-DC power converter system (604) is configured to convert the power generated by the photovoltaic units (702aa - 702nb) so that it can be used by the vehicle (801), particularly its low-voltage battery (803) and high-voltage battery (804). The vehicle (801) is, for example, a commercially available vehicle, such as a vehicle for use on public roads.

[0139] The invention according to the present disclosure will also be described in the following sections.

[0140] 1. A three-port isolated active bridge DC-DC power converter (101), comprising: a control unit (102); a primary side (103), comprising: a first primary port (105); a second primary port (106); two primary switching elements (107a, 107b); a primary converter inductance (108), wherein the two primary switching elements (107a, 107b) and the primary converter inductance (108) are arranged to form a half-bridge arrangement for bidirectionally converting power between the first primary port (105) and the second primary port (106); a primary transformer winding (109); and the primary side (103) configured such that the control unit (102) controls the two primary switching elements (107a, 107b) to convert power between the first primary port (105) and the second primary port (106); a secondary side (104), comprising: a secondary port (111); two secondary switching elements (112a, 112b); a secondary transformer winding (113) magnetically coupled to the primary transformer winding (109); and the secondary side (104) configured such that the two primary switching elements (107a, 107b), the primary transformer winding (109), the two secondary switching elements (112a, 112b), and the secondary transformer winding (113) are arranged to form an isolated DC-DC converter between the primary side (103) and the secondary side (104); a blocking switch (110); and The control unit (102) is configured to open the blocking switch (110) to prevent the flow of power between the primary side (103) and the secondary side (104), and to close the blocking switch (110) to enable the flow of power between the primary side (103) and the secondary side (104). A three-port isolated active bridge DC-DC power converter (101) in which the control unit (102) is configured to control two primary-side switching elements (107a, 107b) and two secondary-side switching elements (112a, 112b) to convert power between the primary-side ports (105, 106) and the secondary-side port (111).

[0141] 2. The first primary-side port (105) is an input power port arranged to be connected to an input power source. The second primary-side port (106) is a low-voltage port arranged to be connected to a low-voltage power storage. The three-port isolated active bridge DC-DC power converter (101) according to item 1, wherein the secondary-side port (111) is a high-voltage port arranged to be connected to a high-voltage power storage.

[0142] 3. The three-port isolated active bridge DC-DC power converter (101) according to item 1 or item 2, wherein the two primary-side switching elements (107a, 107b) and the primary-side converter inductance (108) are arranged to form a buck converter or a boost converter.

[0143] 4. The three-port isolated active bridge DC-DC power converter (101) according to any one of items 1 to 3, wherein the primary side (103) includes a blocking switch (110).

[0144] 5. The three-port isolated active bridge DC-DC power converter (101) according to item 4, wherein the blocking switch (110) is connected in series with the primary-side transformer winding (109).

[0145] 6. The three-port isolated active bridge DC-DC power converter (101) according to any one of claims 1 to 3, wherein the secondary side (104) comprises a blocking switch (110).

[0146] 7. The three-port isolated active bridge DC-DC power converter (101) according to claim 6, wherein the blocking switch (110) is connected in series to the secondary transformer winding (113).

[0147] 8. The primary side (103) comprises two additional primary side switching elements (107c, 107d), The three-port isolated active bridge DC-DC power converter (101) according to any one of the preceding claims, wherein the four primary side switching elements (107a, 107b, 107c, 107d) are arranged to form a primary side full bridge.

[0148] 9. The secondary side (104) comprises two additional secondary side switching elements (112c, 112d), The three-port isolated active bridge DC-DC power converter (101) according to any one of the preceding claims, wherein the four secondary side switching elements (112a, 112b, 112c, 112d) are arranged to form a secondary side full bridge.

[0149] 10. The three-port isolated active bridge DC-DC power converter (101) according to any one of the preceding claims, wherein the blocking switch (110) comprises two blocking switching elements (114a, 114b), and the two blocking switching elements (114a, 114b) are connected in inverse series.

[0150] 11. A 3-port isolated active bridge DC-DC power converter (101) according to any one of the preceding paragraphs, wherein the control unit (102) is configured to control the primary-side switching elements (107a, 107b, 107c, 107d) and the secondary-side switching elements (112a, 112b, 112c, 112d) to generate a phase shift for determining power transfer between the primary side (103) and the secondary side (104).

[0151] 12. The 3-port isolated active bridge DC-DC power converter (101) is configured to enable power flow from a first power port to a second power port, wherein the first power port is one of a first primary-side port (105), a second primary-side port (106), and a secondary-side port (111), the second power port is one of a first primary-side port (105), a second primary-side port (106), and a secondary-side port (111), and the first power port and the second power port are different, the 3-port isolated active bridge DC-DC power converter (101) according to any one of the preceding paragraphs.

[0152] 13. The 3-port isolated active bridge DC-DC power converter (101) is configured to enable power flow from a first power port and a second power port to a third power port, wherein the first power port is one of a first primary-side port (105), a second primary-side port (106), and a secondary-side port (111), the second power port is one of a first primary-side port (105), a second primary-side port (106), and a secondary-side port (111), the third power port is one of a first primary-side port (105), a second primary-side port (106), and a secondary-side port (111), and the first power port, the second power port, and the third power port are different, the 3-port isolated active bridge DC-DC power converter (101) according to any one of the preceding paragraphs.

[0153] 14. A 3 - port isolated active bridge DC - DC power converter (101) is configured to enable power flow from a first power port to a second power port and a third power port, wherein the first power port is one of a first primary - side port (105), a second primary - side port (106), and a secondary - side port (111), the second power port is one of a first primary - side port (105), a second primary - side port (106), and a secondary - side port (111), the third power port is one of a first primary - side port (105), a second primary - side port (106), and a secondary - side port (111), and the first power port, the second power port, and the third power port are different, and the 3 - port isolated active bridge DC - DC power converter (101) is according to any one of the preceding items.

[0154] 15. A plurality of 3 - port isolated active bridge DC - DC power converters (101a - 101n) according to any one of the preceding items, a first system port (602), and a second system port (603) are provided, wherein the plurality of 3 - port isolated active bridge DC - DC power converters (101a - 101n) are coupled in parallel via their second primary - side ports (106a - 106n) so as to form the first system port (602), and the plurality of 3 - port isolated active bridge DC - DC power converters (101a - 101n) are coupled in series via their secondary - side ports (111a - 111n) so as to form the second system port (603), and it is a 3 - port isolated active bridge DC - DC power converter system (601).

[0155] 16. The first system port (602) is a low - voltage port arranged to be connected to a low - voltage power storage, The three-port isolated active bridge DC-DC power converter system (601) according to item 15, wherein the second system port (603) is a high-voltage port arranged to be connected to a high-voltage power storage

[0156] 17. One of the three-port isolated active bridge DC-DC power converters (101a to 101n) is designated as a master power converter, and the control unit (102) of the master power converter is configured to control the output current of the master power converter based on an output current set value. The remaining three-port isolated active bridge DC-DC power converters (101a to 101n) are designated as slave power converters, and the control unit (102) of each slave power converter is configured to control the output voltage of each of its slave power converters to match the output voltage of the master power converter, or the control unit (102) of each slave power converter controls the output voltage of each of its slave power converters to be the reciprocal of the product of the number of three-port isolated active bridge DC-DC power converters (101a to 101n) in the three-port isolated active bridge DC-DC power converter system ( 601 ) and the output voltage of the second system port, in the three-port isolated active bridge DC-DC power converter system according to item 15 or item 16 ( 6 01)

[0157] 18. A control unit (402), and a primary side (403), wherein a plurality of first primary side ports (405a, 405b), a second primary side port (406), and for each first primary side port ( 4 05a, 4 05b), two primary side switching elements (407a, 407b, 407c, 407d), and Primary-side converter inductances (408a, 408b) for each of the first primary ports (405a, 405b), wherein each pair of primary-side switching elements (407a, 407b, 407c, 407d) and their respective primary-side converter inductances (408a, 408b) are arranged to form a half-bridge arrangement for bidirectional power conversion between their respective first primary ports (405a, 405b) and the second primary port (406), the primary-side converter inductances (408a, 408b); Primary-side transformer windings (409a, 409b) for each of the first primary ports (405a, 405b); Comprising; A primary side (403), wherein a control unit (402) is configured to control each pair of primary-side switching elements (407a, 407b, 407c, 407d) to convert power between their respective first primary ports (405a, 405b) and the second primary port (406); A secondary side (404), wherein A secondary port (404); Two secondary-side switching elements (412a, 412b); A secondary-side transformer winding (413) magnetically coupled to each primary-side transformer winding (409a, 409b); Comprising; The secondary side (404), wherein the primary-side switching elements (407a, 407b, 407c, 407d), the primary-side transformer windings (109a, 109b), the two secondary-side switching elements (412a, 412b), and the secondary-side transformer winding (413) are arranged to form an isolated DC-DC converter between the primary side (403) and the secondary side (404); A multi-port isolated active-bridge DC-DC power converter (401) comprising; A multi-port isolated active bridge DC-DC power converter (401) configured such that a control unit controls primary-side switching elements (407a, 407b, 407c, 407d) and two secondary-side switching elements (412a, 412b) to convert power between a primary-side port (405a, 405b, 406) and a secondary-side port (411).

[0158] 19. Each first primary-side port (405) is an input power port arranged to be connected to an input power source, The second primary-side port (406) is a low-voltage port arranged to be connected to a low-voltage power storage, The multi-port isolated active bridge DC-DC power converter (401) according to item 18, wherein the secondary-side port (411) is a high-voltage port arranged to be connected to a high-voltage power storage.

[0159] 20. Each pair of primary-side switching elements (407a, 407b, 407c, 407d) and their respective primary-side converter inductances (408a, 408b) of the multi-port isolated active bridge DC-DC power converter (401) according to item 18 or item 19 are arranged to form a buck converter or a boost converter.

[0160] 21. The primary side (403) includes two additional primary-side switching elements (407e, 407f, 407g, 407h) for each first primary-side port (405a, 405b), The multi-port isolated active bridge DC-DC power converter (401) according to any one of items 18 to 20, wherein each set of four primary-side switching elements (407a, 407b, 407c, 407d, 407e, 407f, 407g, 407h) is arranged to form a primary-side full bridge for each first primary-side port (405a, 405b).

[0161] 22. The secondary side (404) includes two additional secondary-side switching elements (412c, 412d), A multi-port isolated active bridge DC-DC power converter (401) according to any one of claims 18 to 21, in which four secondary-side switching elements (412a, 412b, 412c, 412d) are arranged to form a secondary-side full bridge.

[0162] 23. The multi-port isolated active bridge DC-DC power converter (401) according to any one of claims 18 to 22, comprising blocking switches (410a, 410b) for each of the first primary ports (405a, 405b), wherein a control unit is configured to open the blocking switches (410a, 410b) to prevent power flow between the primary side (403) and the secondary side (404), and to close the blocking switches (410a, 410b) to enable power flow between the primary side (403) and the secondary side (404).

[0163] 24. The multi-port isolated active bridge DC-DC power converter (401) according to claim 23, wherein the primary side (403) comprises blocking switches (410a, 410b).

[0164] 25. The multi-port isolated active bridge DC-DC power converter (401) according to claim 24, wherein each blocking switch (410a, 410b) is connected in series to a respective primary-side transformer winding (409a, 409b).

[0165] 26. The secondary side (403) further comprises blocking switches (410a, 410b), The control unit (402) is configured to open the blocking switches (410a, 410b) to prevent the flow of power between the primary side (403) and the secondary side (404), and to close the blocking switches (410a, 410b) to enable the flow of power between the primary side (403) and the secondary side (404), the multi-port isolated active bridge DC-DC power converter (401) according to any one of claims 18 to 22.

[0166] 27. The multi-port isolated active bridge DC-DC power converter (401) according to claim 26, wherein the blocking switches (410a, 410b) are connected in series to the secondary transformer winding (413).

[0167] 28. The multi-port isolated active bridge DC-DC power converter (401) according to any one of claims 23 to 27, wherein each blocking switch (410a, 410b) comprises two blocking switching elements (414a, 414b, 414c, 414d), and each pair of the blocking switching elements (414a, 414b, 414c, 414d) are connected in inverse series.

[0168] 29. The multi-port isolated active bridge DC-DC power converter (401) according to any one of claims 13 to 28, wherein the control unit is configured to control the primary side switching elements (407a, 407b, 407c, 407d, 407e, 407f, 407g, 407h) and the secondary side switching elements (412a, 412b, 412c, 412d) to generate a phase shift for determining power transfer between the primary side (403) and the secondary side (404).

[0169] 30. The multi-port isolated active bridge DC-DC power converter (401) is configured to enable the flow of power from a first power port to a second power port, wherein the first power port is one of the second primary side port (406) and the secondary side port (411), The second power port is one of a second primary port (406) and a secondary port (411), a multi-port isolated active bridge DC-DC power converter (401) according to any one of items 18 to 29, wherein the first power port and the second power port are different.

[0170] 31. The multi-port isolated active bridge DC-DC power converter (401) is configured to enable power to flow from each of the first primary power ports (405a, 405b) to the first power port, a multi-port isolated active bridge DC-DC power converter (401) according to any one of items 18 to 30, wherein the first power port is one of a second primary port (406) and a secondary port (411).

[0171] 32. The multi-port isolated active bridge DC-DC power converter (401) is configured to enable power to flow from each of the first primary power ports (405a, 405b) and the first power port to the second power port, wherein the first power port is one of a second primary port (406) and a secondary port (411), the second power port is one of a second primary port (406) and a secondary port (411), a multi-port isolated active bridge DC-DC power converter (401) according to any one of items 18 to 31, wherein the first power port and the second power port are different.

[0172] 33. The multi-port isolated active bridge DC-DC power converter (401) is configured to enable power to flow from the first power port to each of the first primary power ports (405a, 405b), a multi-port isolated active bridge DC-DC power converter (401) according to any one of items 18 to 32, wherein the first power port is one of a second primary port (406) and a secondary port (411).

[0173] 34. A multi-port isolated active bridge DC-DC power converter (401) is configured to enable the flow of power from a first power port to each of a first primary port (405a, 405b) and a second power port, wherein the first power port is one of a second primary port (406) and a secondary port (411), the second power port is one of a second primary port (406) and a secondary port (411), and the first power port and the second power port are different multi-port isolated active bridge DC-DC power converters (401) according to any one of items 18 to 33.

[0174] 35. A multi-port isolated active bridge DC-DC power converter system (604) comprising a plurality of multi-port isolated active bridge DC-DC power converters (401a to 401n) according to any one of items 18 to 34, a first system port (602), and a second system port (603), wherein the plurality of multi-port isolated active bridge DC-DC power converters (401a to 401n) are coupled in parallel via their second primary ports (406a to 406n) so as to form the first system port (602), and the plurality of multi-port isolated active bridge DC-DC power converters (401a to 401n) are coupled in series via their secondary ports (411a to 411n) so as to form the second system port (603). A multi-port isolated active bridge DC-DC power converter system (604).

[0175] 36. The first system port (602) is a low-voltage port arranged to be connected to a low-voltage power storage, The multi-port isolated active bridge DC-DC power converter system (604) according to item 35, wherein the second system port (603) is a high-voltage port arranged to be connected to a high-voltage power storage.

[0176] 37. One of the multi-port isolated active bridge DC-DC power converters (401a to 401n) is designated as a master power converter, and the control unit (402) of the master power converter is configured to control the output current of the master power converter based on an output current set value. The remaining multi-port isolated active bridge DC-DC power converters (401a to 401n) are designated as slave power converters, and the control unit (402) of each slave power converter is configured to control the output current of its respective slave power converter to match the output voltage of the master power converter, or the control unit (402) of each slave power converter is configured to control the output voltage of its respective slave power converter to be the reciprocal of the product of the number of multi-port isolated active bridge DC-DC power converters (401a to 401n) in the multi-port isolated active bridge DC-DC power converter system (604) and the output voltage of the second system port. The multi-port isolated active bridge DC-DC power converter system (604) according to item 35 or item 36.

[0177] 38. A plurality of photovoltaic units ( 702 aa~ 702 nb) and A power converter system which is either the three-port isolated active bridge DC-DC power converter system (601) according to items 15 to 17 or the multi-port isolated active bridge DC-DC power converter system (604) according to items 35 to 37, and A photovoltaic power assembly (701) comprising A solar power assembly (701) in which each of a plurality of solar power generation units (702aa to 702nb) is connected to a single first primary port (105a to d, 405a to h) of a power converter system.

[0178] 39. A body (802), The solar power assembly (701) according to item 38, A low-voltage battery (803), A high-voltage battery (804) A vehicle (801) comprising: A plurality of solar power generation units (702aa to 702nb) of the solar power assembly (701) are mechanically attached to the body (802), A vehicle (801) in which the low-voltage battery (803) is connected to a first system port (602) of a power converter system (601) of the solar power assembly (701), and the high-voltage battery (804) is connected to a second system port (603) of the power converter system of the solar power assembly (701).

Explanation of reference numerals

[0179] 101 3-port isolated active bridge DC-DC power converter 102 Control unit 103 Primary side 104 Secondary side 105 First primary port, primary port 105a First primary port 105b First primary port 105c First primary port 105d First primary port 106 Second primary port, primary port 106a Second primary port 106b Second primary port 106c Second primary port 106d Second primary port 107a Primary side switching element 107b Primary side switching element 107c Primary side switching element 107d Primary side switching element 108 Primary side converter inductance 109 Primary side transformer winding, primary side winding 110 Blocking switch 111 Secondary side port 111a Secondary side port 111b Secondary side port 111c Secondary side port 111d Secondary side port 112a Secondary side switching element 112b Secondary side switching element 112c Secondary side switching element 112d Secondary side switching element 113 Secondary side transformer winding 114a Blocking switching element 114b Blocking switching element 401 Multi-port isolated active bridge DC-DC power converter 401a Multi-port isolated active bridge DC-DC power converter 401b Multi-port isolated active bridge DC-DC power converter 401c Multi-port isolated active bridge DC-DC power converter 401d Multi-port isolated active bridge DC-DC power converter 402 Control unit 403 Primary side 404 Secondary side 405a First primary side port, first first primary side port 405b First primary side port, second first primary side port 406 Second primary side port 407a Primary side switching element 407b Primary side switching element 407c Primary side switching element 407d Primary side switching element 407e Primary side switching element 407f Primary side switching element 407g Primary side switching element 407h Primary side switching element 408a Primary side converter inductance 408b Primary side converter inductance 409a Primary side transformer winding, first primary side transformer winding 409b Primary side transformer winding, second primary side transformer winding 410a Blocking switch, first blocking switch 410b Blocking switch, second blocking switch 411 Secondary side port 412a Secondary side switching element 412b Secondary side switching element 412c Secondary side switching element 412d Secondary side switching element 413 Secondary side transformer winding 414a Blocking switching element 414b Blocking switching element 414c Blocking switching element 414d Blocking switching element 601 3-port isolated active bridge DC-DC power converter system 602 First system port 603 Second system port 604 Multi-port isolated active bridge DC-DC power converter system 604aa - 604nb Solar power generation unit 701 Solar power assembly 702aa~702nb Solar power generation unit 801 Vehicle 802 Body 803 Low voltage battery 804 High voltage battery

Claims

Claim 1 A three-port isolated active bridge DC-DC power converter system (601), comprising a plurality of three-port isolated active bridge DC-DC power converters (101a to 101n), each of which has a control unit (102), a primary side (103), which has a single first primary port (105), a single second primary port (106), two primary side switching elements (107a, 107b), a primary side converter inductance (108), wherein the two primary side switching elements (107a, 107b) and the primary side converter inductance (108) are arranged to form a half-bridge arrangement for bidirectional power conversion between the first primary port (105) and the second primary port (106), and a primary side transformer winding (109), and is provided with, wherein the control unit (102) is configured to control the two primary side switching elements (107a, 107b) to convert power between the first primary port (105) and the second primary port (106), a primary side (103), a secondary side (104), which has a single secondary port (111), two secondary side switching elements (112a, 112b), and a secondary side transformer winding (113) magnetically coupled to the primary side transformer winding (109), and is provided with, wherein the two primary side switching elements (107a, 107b), the primary side transformer winding (109), the two secondary side switching elements (112a, 112b), and the secondary side transformer winding (113) are arranged to form an isolated DC-DC converter between the primary side (103) and the secondary side (104), a secondary side (104), and a blocking switch (110), and is provided with, wherein the control unit (102) is configured to open the blocking switch (110) to prevent power flow between the primary side (103) and the secondary side (104), and to close the blocking switch (110) to enable power flow between the primary side (103) and the secondary side (104). configured such that the control unit (102) controls the two primary-side switching elements (107a, 107b) and the two secondary-side switching elements (112a, 112b) to convert power between the primary-side ports (105, 106) and the secondary-side port (111), a plurality of three-port isolated active bridge DC-DC power converters (101a to 101n), a first system port (602), a second system port (603) and, the plurality of three-port isolated active bridge DC-DC power converters (101a to 101n) are coupled in parallel via the second primary-side ports (106a to 106n) so as to form the first system port (602), the plurality of three-port isolated active bridge DC-DC power converters (101a to 101n) are coupled in series via the secondary-side ports (111a to 111n) so as to form the second system port (603), one of the three-port isolated active bridge DC-DC power converters (101a to 101n) is designated as a master power converter, and the control unit (102) of the master power converter is configured to control the output current of the master power converter based on an output current set value, and the output current of the master power converter is the output current flowing through the secondary-side port of the master power converter, The remaining three-port isolated active bridge DC-DC power converters (101a to 101n) are designated as slave power converters, and each control unit (102) of the slave power converters is configured to control the output voltage of each slave power converter to match the output voltage of the master power converter. The output voltage of each slave power converter is the output voltage of the secondary-side port of each slave power converter, and the output voltage of the master power converter is the output voltage of the secondary-side port of the master power converter. Or each control unit (102) of the slave power converters is configured to control the output voltage of each slave power converter to be the reciprocal of the product of the number of three-port isolated active bridge DC-DC power converters (101a to 101n) of the three-port isolated active bridge DC-DC power converter system (601) and the output voltage of the second system port. A three-port isolated active bridge DC-DC power converter system (601).

2. Each three-port isolated active bridge DC-DC power converter (101a to 101n) is configured to allow power to flow from a first power port to a second power port. The first power port is one of the first primary-side ports (105a to 105n), the second primary-side ports (106a to 106n), and the secondary-side ports (111a - 111n). The second power port is one of the first primary-side ports (105a to 105n), the second primary-side ports (106a to 106n), and the secondary-side ports (111a - 111n). The first power port and the second power port are different and / or Each three-port isolated active bridge DC-DC power converter (101a to 101n) is configured to allow power to flow from the first power port and the second power port to a third power port. The first power port is one of the first primary-side ports (105a to 105n), the second primary-side ports (106a to 106n), and the secondary-side ports (111a to 111n). The second power port is one of the first primary side ports (105a to 105n), the second primary side ports (106a to 106n), and the secondary side ports (111a to 111n), The third power port is one of the first primary side ports (105a to 105n), the second primary side ports (106a to 106n), and the secondary side ports (111a to 111n), the first power port, the second power port, and the third power port are different and / or each three-port isolated active bridge DC-DC power converter (101a to 101n) is configured to enable the flow of power from the first power port to the second power port and the third power port, The first power port is one of the first primary side ports (105a to 105n), the second primary side ports (106a to 106n), and the secondary side ports (111a to 111n), The second power port is one of the first primary side ports (105a to 105n), the second primary side ports (106a to 106n), and the secondary side ports (111a to 111n), The third power port is one of the first primary side ports (105a to 105n), the second primary side ports (106a to 106n), and the secondary side ports (111a to 111n), the first power port, the second power port, and the third power port are different, the three-port isolated active bridge DC-DC power converter system (601) according to claim 1.

3. The first system port (602) is a low voltage port arranged to be connected to a low voltage power storage, The second system port (603) is a high voltage port arranged to be connected to a high voltage power storage, the three-port isolated active bridge DC-DC power converter system (601) according to claim 1.

4. A multi-port isolated active bridge DC-DC power converter (401), comprising a control unit (402), a primary side (403), comprising a plurality of first primary side ports (405a, 405b), a second primary side port (406), Two primary switching elements (407a, 407b, 407c, 407d) for each of the first primary ports (405a, 405b), Primary converter inductances (408a, 408b) for each of the first primary ports (405a, 405b), wherein each pair of primary switching elements (407a, 407b, 407c, 407d) and their respective primary converter inductances (408a, 408b) are arranged to form a half-bridge arrangement for bidirectional power conversion between their respective first primary ports (405a, 405b) and the second primary port (406), the primary converter inductances (408a, 408b); Primary transformer windings (409a, 409b) for each of the first primary ports (405a, 405b) Comprising A primary side (403), wherein the control unit (402) is configured to control each pair of primary switching elements (407a, 407b, 407c, 407d) to convert power between each of the first primary ports (405a, 405b) and the second primary port (406); A secondary side (404), A secondary port (411), Two secondary switching elements (412a, 412b), And a single secondary transformer winding (413) magnetically coupled to each primary transformer winding (409a, 409b) Comprising A secondary side (404), wherein the primary switching elements (407a, 407b, 407c, 407d), the primary transformer windings (109a, 109b), the two secondary switching elements (412a, 412b), and the secondary transformer winding (413) are arranged to form an isolated DC-DC converter between the primary side (403) and the secondary side (404); Comprising A multi-port isolated active bridge DC-DC power converter (401), wherein the control unit is configured to control the primary switching elements (407a, 407b, 407c, 407d) and the two secondary switching elements (412a, 412b) to convert power between the primary ports (405a, 405b, 406) and the secondary port (411). Claim 5 Each pair of the primary - side switching elements (407a, 407b, 407c, 407d) and the respective primary - side converter inductances (408a, 408b) are arranged to form a buck converter or a boost converter, the multi - port isolated active - bridge DC - DC power converter (401) according to claim 4.

6. The primary side (403) includes two additional primary - side switching elements (407e, 407f, 407g, 407h) for each of the first primary - side ports (405a, 405b), Each set of four primary - side switching elements (407a, 407b, 407c, 407d, 407e, 407f, 407g, 407h) is arranged to form a primary - side full - bridge for each of the first primary - side ports (405a, 405b), The secondary side (404) includes two additional secondary - side switching elements (412c, 412d), The four secondary - side switching elements (412a, 412b, 412c, 412d) are arranged to form a secondary - side full - bridge, the multi - port isolated active - bridge DC - DC power converter (401) according to claim 4.

7. The multi - port isolated active - bridge DC - DC power converter (401) further includes blocking switches (410a, 410b) for each of the first primary - side ports (405a, 405b), The control unit (402) is configured to open the blocking switches (410a, 410b) to prevent the flow of power between the primary side (403) and the secondary side (404), and to close the blocking switches (410a, 410b) to enable the flow of power between the primary side (403) and the secondary side (404), The primary side (403) includes the blocking switches (410a, 410b), Each blocking switch (410a, 410b) is connected in series with the respective primary - side transformer winding (409a, 409b), the multi - port isolated active - bridge DC - DC power converter (401) according to claim 4.

8. The secondary side (403) further includes blocking switches (410a, 410b), The control unit (402) is configured to open the blocking switches (410a, 410b) to prevent the flow of power between the primary side (403) and the secondary side (404), and to close the blocking switches (410a, 410b) to enable the flow of power between the primary side (403) and the secondary side (404). The blocking switches (410a, 410b) are connected in series to the secondary transformer winding (413). The multi-port isolated active bridge DC-DC power converter (401) according to claim 4, wherein each blocking switch (410a, 410b) includes two blocking switching elements (414a, 414b, 414c, 414d), and each pair of the blocking switching elements (414a, 414b, 414c, 414d) are connected in inverse series.

9. The multi-port isolated active bridge DC-DC power converter (401) according to claim 4, wherein the control unit is configured to control the primary side switching elements (407a, 407b, 407c, 407d, 407e, 407f, 407g, 407h) and the secondary side switching elements (412a, 412b, 412c, 412d) to generate a phase shift for determining power transfer between the primary side (403) and the secondary side (404).

10. The multi-port isolated active bridge DC-DC power converter (401) is configured to enable the flow of power from a first power port to a second power port. The first power port is one of the second primary side port (406) and the secondary side port (411). The second power port is one of the second primary side port (406) and the secondary side port (411). The first power port and the second power port are different and / or The multi-port isolated active bridge DC-DC power converter (401) is configured to enable the flow of power from each of the first primary side power ports (405a, 405b) to the first power port. The first power port is one of the second primary side port (406) and the secondary side port (411) and / or The multi-port isolated active bridge DC-DC power converter (401) is configured to enable power flow from each of the first primary-side power ports (405a, 405b) and from the first power port to the second power port. The first power port is one of the second primary-side port (406) and the secondary-side port (411). The second power port is one of the second primary-side port (406) and the secondary-side port (411). The first power port and the second power port are different and / or The multi-port isolated active bridge DC-DC power converter (401) is configured to enable power flow from the first power port to each of the first primary-side power ports (405a, 405b). The first power port is one of the second primary-side port (406) and the secondary-side port (411) and / or The multi-port isolated active bridge DC-DC power converter (401) is configured to enable power flow from the first power port to each of the first primary-side power ports (405a, 405b) and to the second power port. The first power port is one of the second primary-side port (406) and the secondary-side port (411). The second power port is one of the second primary-side port (406) and the secondary-side port (411). The first power port and the second power port are different. The multi-port isolated active bridge DC-DC power converter (401) according to claim 4.

11. A multi-port isolated active bridge DC-DC power converter system (604), comprising: A plurality of multi-port isolated active bridge DC-DC power converters (401a to 401n) according to any one of claims 4 to 10; A first system port (602); A second system port (603) wherein the plurality of multi-port isolated active bridge DC-DC power converters (401a to 401n) are coupled in parallel via the second primary-side ports (406a to 406n) so as to form the first system port (602). ​ The multi-port isolated active bridge DC-DC power converter system (604) in which the plurality of multi-port isolated active bridge DC-DC power converters (401a to 401n) are coupled in series via the secondary ports (411a to 411n) so as to form the second system port (603).

12. The first system port (602) is a low-voltage port arranged to be connected to a low-voltage power storage, The multi-port isolated active bridge DC-DC power converter system (604) according to claim 11, wherein the second system port (603) is a high-voltage port arranged to be connected to a high-voltage power storage.

13. One of the multi-port isolated active bridge DC-DC power converters (401a to 401n) is designated as a master power converter, and the control unit (402) of the master power converter is configured to control the output current of the master power converter based on an output current set value, and the output current of the master power converter is the output current flowing through the secondary port of the master power converter, The remaining multi-port isolated active bridge DC-DC power converters (401a to 401n) are designated as slave power converters, and the control unit (402) of each of the slave power converters is configured to control the output voltage of each slave power converter to match the output voltage of the master power converter, and the output voltage of each slave power converter is the output voltage of the secondary port of each of the slave power converters, and the output voltage of the master power converter is the output voltage of the secondary port of the master power converter, or the control unit (402) of each of the slave power converters is configured to control the output voltage of each of the slave power converters to be the reciprocal of the product of the number of the multi-port isolated active bridge DC-DC power converters (401a to 401n) in the multi-port isolated active bridge DC-DC power converter system (604) and the output voltage of the second system port. The multi-port isolated active bridge DC-DC power converter system (604) according to claim 11.

14. A solar power assembly (701), comprising a plurality of solar power generation units (702aa to 702nb), and a power converter system which is either the three-port isolated active bridge DC-DC power converter system (601) according to claim 1 or the multi-port isolated active bridge DC-DC power converter system (604) according to claim 11, wherein each of the plurality of solar power generation units (702aa to 702nb) of the solar power assembly (701) is connected to a single first primary-side port (105a to d, 405a to h) of the power converter system.

15. A vehicle (801), comprising a body (802), the solar power assembly (701) according to claim 14, a low-voltage battery (803), and a high-voltage battery (804), wherein the plurality of solar power generation units (702aa - 702nb) of the solar power assembly (701) are mechanically attached to the body (802), the low-voltage battery (803) is connected to the first system port (602) of the power converter system (601) of the solar power assembly (701), and the high-voltage battery (804) is connected to the second system port (603) of the power converter system of the solar power assembly (701). ​ ​

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