Electrical power management module

Abstract

An electrical power management module (1a,1b) configured to provide electrical power between a battery (2a, 2b) and a power bus (3) of a vehicle, the electrical power management module (1a,1b) comprising a DC-DC converter configured to provide electrical power when the power bus voltage is higher than the battery voltage, and when the power bus voltage is lower than the battery voltage. The DC-DC converter is a non-isolated bidirectional buck-boost converter without series-connected capacitive elements, and is configured to work in buck mode, boost mode or buck-boost and pass-thru mode.

Description

[0001] DESCRIPTION

[0002] Electrical power management module

[0003] TECHNICAL SECTOR

[0004] The present invention relates to an electric power management module configured to supply power between an electric vehicle battery and a power bus of said vehicle, to a power distribution system for an electric vehicle, to a power unit for an electric vehicle, to an electric vehicle, and to a method for controlling a power distribution system.

[0005] PRIOR STATE OF THE ART

[0006] Power distribution systems configured to connect multiple batteries to a power bus are well-known. These systems supply electrical power from the batteries to the power bus and receive electrical power from the power bus back to the batteries. This type of power distribution system is commonly used in light vehicles, such as motorcycles.

[0007] On the one hand, there are known power distribution systems that connect the batteries one by one to the power bus so that a sequential discharge of said batteries occurs.

[0008] On the other hand, power distribution systems that allow several batteries to be connected simultaneously to the same power bus are also well known.

[0009] For example, ES2941800A1, belonging to the same applicant, relates to an intelligent power distribution system for electric vehicles and a procedure for implementing such a system. The intelligent power distribution system comprises electronic equipment equipped with connection means to two or more battery modules as well as to the vehicle's power bus, allowing said electronic equipment to operate the battery modules in parallel for simultaneous charging and discharging when such a configuration is optimal.

[0010] Finally, US11370308B1 refers to an electrical power management module configured to supply power from a battery to a power bus and to charge the battery from the power bus. The electrical power management module comprises a bidirectional buck-boost DC-DC converter and a switching circuit connected in parallel to the DC-DC converter. The type of bidirectional buck-boost DC-DC converter used allows power to be supplied between the battery and the power bus when the power bus voltage is higher than the battery voltage.The electrical power management module is configured to supply power through the DC-DC converter if the difference between the battery voltage and the power bus voltage exceeds a preset threshold value, and to supply power through the switching circuit if the difference between the battery voltage and the power bus voltage is below the preset threshold value.

[0011] EXPLANATION OF THE INVENTION

[0012] The object of the invention is to provide an electric power management module configured to supply power between an electric vehicle battery and a power bus of said vehicle, a power distribution system for an electric vehicle, a power unit for a vehicle, an electric vehicle, and a method for controlling a power distribution system.

[0013] A first aspect of the invention relates to an electrical power management module configured to supply power between an electric vehicle battery and the vehicle's power bus. The DC-DC converter allows power to be supplied from the battery to the power bus, and also allows power to be supplied from the power bus back to the battery for charging. The battery can be charged by connecting the power bus to a charger, and also when the vehicle is operating in regenerative braking mode.

[0014] The electrical power management module comprises a DC-DC converter whose input is configured to connect to a vehicle battery, and whose output is configured to connect to a vehicle power bus. The DC-DC converter is a non-isolated, bidirectional buck-boost converter without series-connected capacitive elements, and is configured to supply power when the power bus voltage is higher than the battery voltage and also when the power bus voltage is lower than the battery voltage.

[0015] In addition, the DC-DC converter is configured to work in buck mode, boost mode, or buck-boost mode if the difference between the battery voltage and the power bus voltage exceeds a preset threshold value, and in pass-thru mode if the difference between the battery voltage and the power bus voltage is less than the preset threshold value.

[0016] In pass-thru mode, the DC-DC converter switches necessary to allow current flow between the input and output of the DC-DC converter remain closed and unswitched. This eliminates switching losses and electromagnetic interference, maximizing efficiency. Using the converter's own components to connect the battery to the power bus without switching losses eliminates the need for a switching circuit like the one used in US patent 11370308B1. This simplifies the power management module without compromising its effectiveness.

[0017] Furthermore, the use of a buck-boost converter configuration that allows power to be supplied between the battery and the power bus regardless of whether the battery voltage is higher or lower than the bus voltage allows the battery discharge to be managed according to different criteria such as: battery longevity, maximization of vehicle performance, user recharging convenience, etc.

[0018] In the case of the DC-DC converters used in US11370308B1, the DC-DC converter only operates when the battery voltage is lower than the power bus voltage. In this case, several batteries with different bus voltages can be connected, with the battery with the highest voltage connected directly to the power bus and the rest connected through the DC-DC power converter. However, the control unit could not choose to connect the battery with the lowest voltage directly to the power bus and connect the remaining batteries with a higher voltage than the bus voltage through the corresponding DC-DC converter because the DC-DC topologies described in the patent do not allow for such operation.

[0019] A second aspect of the invention relates to a power distribution system for an electric vehicle comprising N batteries and a power bus.

[0020] The power distribution system comprises N connection modules, each connection module comprising a first connection interface configured to connect to a respective vehicle battery, and a second connection interface configured to connect to the vehicle's power bus.

[0021] Furthermore, at least N-1 of said connection modules comprises an electrical power management module as described above, so that each of said connection modules can connect the respective battery to the power bus, with the corresponding DC-DC converter working in buck, boost, buck-boost or pass-thru mode, allowing the distribution system to flow energy between several batteries and the power bus at the same time.

[0022] A third aspect of the invention relates to a power unit for a vehicle comprising a power bus, the power unit being configured to connect to said power bus.

[0023] The power unit comprises a plurality of battery cells connected in series or in parallel, and a battery management system (BMS), with an electrical power management module according to the first aspect of the invention being integrated into the battery management system (BMS).

[0024] A fourth aspect of the invention relates to an electric vehicle.

[0025] Preferably, the electric vehicle comprises a plurality of batteries, a power bus, and a power distribution system as described in the second aspect of the invention configured to connect the batteries to the power bus.

[0026] Alternatively, the electric vehicle comprises a power bus and a plurality of power units as described in the third aspect of the invention connected to said power bus, the power units communicating with each other via a communication bus. A fifth aspect of the invention relates to a method for controlling a power distribution system as described in the second aspect of the invention.

[0027] In the case of all connection modules of the power distribution system comprising a respective electrical power management module, the method comprises the following stages: a stage in which, depending on the state of charge of the batteries and based on one or more of the following criteria: battery longevity, maximization of vehicle performance, user recharging convenience, etc.The batteries to be connected to the power bus are determined, a stage in which the bus voltage is established which will correspond to the battery voltage of at least one of the batteries to be connected, and the working parameters of the DC-DC converters of the batteries to be connected and whose battery voltage has a difference with the established bus voltage that exceeds the preset threshold value are calculated, and a stage in which the DC-DC converter(s) of the batteries to be connected and whose battery voltage has a difference with the established bus voltage that does not exceed the preset threshold value are connected to the power bus in pass-thru mode, and the rest of the batteries to be connected are connected to the power bus with the DC-DC converter in buck, boost or buck-boost mode working with the defined working parameters.

[0028] Conversely, when a power distribution system connection module lacks an electrical power management module, the method comprises the following stages: a stage in which the bus voltage is established that corresponds to the battery voltage whose connection module lacks an electrical power management module, a stage in which, depending on the state of charge of the batteries and based on one or more of the following criteria: battery longevity, maximization of vehicle performance, user recharging convenience, etc.If it is deemed necessary to connect the remaining batteries to the power bus, a stage is determined in which the working parameters of the DC-DC converters of the batteries to be connected are calculated and whose battery voltage has a difference with the established bus voltage that exceeds the preset threshold value, and a stage in which the DC-DC converter(s) of the battery(ies) to be connected and whose battery voltage has a difference with the established bus voltage that does not exceed the preset threshold value are connected to the power bus in pass-thru mode, and the remaining batteries to be connected are connected to the power bus with the DC-DC converter in buck, boost or buck-boost mode operating with the defined working parameters.

[0029] DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 shows the general scheme of the electrical power management module of the invention.

[0031] Figure 2 shows a graph with the different working zones of the DC-DC converter of the electrical power management module as a function of the voltage difference between the input and output of the DC-DC converter and the sign of the output current of the DC-DC converter.

[0032] Figure 3 shows a table that defines the working mode of the DC-DC converter of the electrical power management module based on the relationship between the input voltage and the output voltage of the converter and the sign of the output current of the DC-DC converter.

[0033] Figure 4 schematically shows a first embodiment of the electrical power management module of the invention.

[0034] Figure 5 schematically shows a second embodiment of the electrical power management module of the invention.

[0035] Figure 6 schematically shows a third embodiment of the electrical power management module of the invention.

[0036] Figure 7 schematically shows the power distribution system of the invention connected to a plurality of batteries and a power bus.

[0037] Figure 8 schematically shows a first embodiment of the power distribution system of the invention connected to a pair of batteries and a power bus.

[0038] Figure 9 schematically shows a second embodiment of the power distribution system of the invention connected to a pair of batteries and a power bus.

[0039] Figure 10 schematically shows a power unit of the invention.

[0040] Figure 11 schematically shows an example of the BMS battery management system of a power unit according to the invention.

[0041] Figure 12 schematically shows the connection of a pair of power units of the invention connected to each other and connected to a power bus.

[0042] DETAILED EXPLANATION OF THE INVENTION

[0043] A first aspect of the invention relates to an electric power management module 1 configured to supply power between a battery 2, 2a, 2b, 2n of an electric vehicle and a power bus 3 of said vehicle. Said electric vehicle could be, for example, a motorcycle, a quadricycle, a tricycle, or a moped.

[0044] The electric power management module 1, 1a, 1b of the invention, whose general scheme is shown in Figure 1, comprises a DC-DC converter whose input 10 is configured to connect to a battery 2, 2a, 2b, 2n of a vehicle, and whose output 11 is configured to connect to a power bus 3 of said vehicle.

[0045] The DC-DC converter is a non-isolated, bidirectional buck-boost converter without series-connected capacitive elements. The DC-DC converter is configured to supply power when the output voltage V ou t, that is, the power bus voltage Vb US , is greater than the voltage at the converter input V! n , that is, the battery voltage Vbat, and also when the voltage at the converter output V ou t is less than the voltage at the converter input V! nThus, the DC-DC converter allows power to be supplied from the corresponding battery 2, 2a, 2b, 2n to the power bus 3, and also allows power to be supplied from the power bus 3 to battery 2, 2a, 2b, 2n for charging said battery 2, 2a, 2b, 2n. Charging of battery 2, 2a, 2b, 2n can be carried out by connecting the power bus 3 to a charger 7, and also when the vehicle operates in regenerative braking.

[0046] The DC-DC converter is configured to work in buck mode, boost mode, or buck-boost mode if the difference between the battery voltage Vbat, i.e., the voltage at the converter input V! n , and the power bus voltage Vb US , that is, the voltage at the converter output V ou t, exceeds a pre-set threshold value Y.

[0047] Furthermore, the DC-DC converter is configured to work in pass-thru mode if the difference between the battery voltage Vbat, i.e., the voltage at the converter input V! n , and the power bus voltage Vb US , that is, the voltage at the converter output V ou t, is lower than the pre-established threshold value Y.

[0048] The graph shown in Figure 2 shows the operating zones of the different operating modes of the DC-DC converter as a function of the difference between the input voltage V! n and the output voltage V ou t of the DC-DC converter, and depending on the sign of the output current lout of the DC-DC converter. In the context of the invention, the output current l will be considered ou t is positive when the current flows from input 10 to output 11 of the DC-DC converter, while the output current l will be considered out is negative when current flows from output 11 to input 10 of the DC-DC converter. When the output current l ou When the DC-DC converter's input t is positive, the battery 2, 2a, 2b, 2n connected to input 10 of the DC-DC converter will supply current to the power bus 3 connected to output 11 of the DC-DC converter, thus discharging the corresponding battery 2, 2a, 2b, 2n. Conversely, when the output current l ou If the input t of the DC-DC converter is negative, it means that the battery 2, 2a, 2b, 2n connected to input 10 receives current from the power bus 3 to which the output 11 of the DC-DC converter is connected, so the corresponding battery 2, 2a, 2b, 2n will be charged. As mentioned previously, this output current l ou t can come from a charger 7 connected to power bus 3 or it can come from power bus 3 if the vehicle has regenerative braking functionality.

[0049] As shown in the graph in Figure 2, the DC-DC converter is configured to work in buck, boost, buck-boost, and pass-thru modes for output currents l ou t of the DC-DC converter positive and negative. In Figure 2, the buck and boost operating modes of the DC-DC converter are called inverse buck mode and inverse boost mode when the output current l ou t of the DC-DC converter is negative.

[0050] The table in Figure 3 details, as an example, the working modes of the DC-DC converter, that is, the conduction modes of the DC-DC converter as a function of the difference between the input voltage V! n and the output voltage V ou t of said DC-DC converter and the sign of the output current l out of said DC-DC converter. To this end, in addition to the threshold value Y mentioned above, a second threshold value X is established to define the operating region of the buck-boost mode. The threshold value Y and the second threshold value X depend on the design of the DC-DC converter's control system, the sizing of passive components such as the inductance L and capacitance C of the DC-DC converter's components, and other parameters of the DC-DC converter itself. The table in Figure 3 also shows a specific example of the DC-DC converter's operating modes as a function of the input voltage V! n for specific output voltage values ​​V ou t, threshold value Y and second threshold value X.

[0051] As mentioned previously, in pass-thru mode, the DC-DC converter switches necessary to allow current flow between the input and output of the DC-DC converter remain closed and unswitched. For example, in the embodiment shown in Figure 4, the upper switches Si and S3 remain closed and unswitched in pass-thru mode.

[0052] The buck-boost mode is a transition mode between the buck, boost (both during charging and discharging of the corresponding battery), and pass-thru modes. In buck-boost mode, the voltage difference between the input voltage V! n and the output voltage V ou t is small, regardless of whether one is larger than the other. For example, in the converter embodiment shown in Figure 4, when the converter operates in buck or boost mode, the switching of 2 of the 4 switches is controlled, while in buck-boost mode all 4 are controlled.

[0053] Figure 4 shows a first embodiment of the electrical power management module 1 in which the DC-DC converter has a “4-switch bidirectional buck-boost converter” topology.

[0054] Figure 5 shows a second embodiment of the electrical power management module 1 in which the DC-DC converter has a “multi-level 4-switch bidirectional Buck-boost converter” topology.

[0055] Figure 6 shows a second embodiment of the electrical power management module 1 in which the DC-DC converter has an “interleaved 4-switch bidirectional buck-boost converter” topology.

[0056] In other possible embodiments (not shown in the figures), the DC-DC converter of the electrical power management module may have a topology that is a variant of the topologies shown in Figures 4 to 6.

[0057] Preferably, when the DC-DC converter operates in buck mode, boost mode, or buck-boost mode, the control of said DC-DC converter is performed based on a current control algorithm, in which the input voltage V is not controlled. n and the output voltage Vout of the DC-DC converter, establishing the control algorithm a reference current Iref that the DC-DC converter must provide, and comparing the control algorithm with said reference current l re f with the output current l ou t received / provided by power bus 3 from / to battery 2, 2a, 2b, 2n through DC-DC converter.

[0058] More preferably, the control algorithm uses a mixed analog-digital control to implement the current control algorithm, by digitally generating the reference current l re f, and analog control of the output current l out. Thus, the control algorithm will comprise an inner analog current control loop and an outer digital current control loop that allows the use of more advanced current control strategies (PID, adaptive control, predictive control, etc.). Preferably, the analog control of the output current l ou The control algorithm is based on peak and valley current control. Thus, the control strategy is a combined analog and digital control strategy, enabling the processing of multiple analog inputs at a high frequency in a high-power converter. The selection of this high frequency is determined by the need to minimize the size of the DC-DC converter's passive components and to optimize its performance.

[0059] A second aspect of the invention relates to a power distribution system 7 for an electric vehicle comprising N batteries 2a, 2b, 2n and a power bus 3.

[0060] Figure 7 shows a general scheme of the power distribution system 7 of the invention connected to a plurality of batteries 2a, 2b, 2n and to a vehicle power bus 3.

[0061] The power distribution system 8 comprises N connection modules 4a, 4b, each connection module 4a, 4b comprising a first connection interface 40a, 40b configured to connect to a respective vehicle battery 2a, 2b, and a second connection interface 41a, 41b configured to connect to the vehicle's power bus 3.

[0062] At least N-1 of said connection modules 4a, 4b comprise an electrical power management module 1a, 1b as described in the first aspect of the invention. Each of said at least N-1 connection modules 4a, 4b can connect the respective battery 2a, 2b to the power bus 3 by operating the corresponding DC-DC converter in buck, boost, buck-boost or pass-thru mode.

[0063] The power distribution system 8 enables the flow of energy between several batteries 2a, 2b and the power bus 3 at the same time.

[0064] Preferably, the power distribution system 8 comprises a control unit 80 configured to decide which of the vehicle's batteries 2a and 2b will be connected to the vehicle's power bus 3 via the corresponding connection modules 4a and 4b. The control unit 80 also determines the operating parameters of the control algorithms for the power modules 1a and 1b of these connection modules 4a and 4b. These operating parameters are determined based on one or more of the following criteria: battery longevity, maximizing vehicle performance, user convenience for recharging, etc. To do this, the control unit 80 is aware of the characteristics of the batteries 2a and 2b, such as capacity, number of cells, state of charge (SoC), and temperature; and in some embodiments, the control unit 80 may also be aware of the vehicle's power requirements.

[0065] If the goal is to prioritize optimizing the lifespan of batteries 2a and 2b, control unit 80 estimates the maximum discharge current for each battery 2a and 2b that minimizes its deterioration. If batteries 2a and 2b have different state of charge (SoC) values, priority will be given to discharging the batteries with the highest SoC to balance the SoC of the different batteries 2a and 2b, ensuring that none of them has to provide a current exceeding the established maximum discharge current. Thus, for example, in the case of a battery 2a, 2b with a higher state of charge (SoC) than the rest, the control unit 80 will establish that it provides all the power required by the vehicle as long as the current to be provided does not exceed the value of the maximum current without deterioration of the respective battery 2a, 2b.If the required power cannot be supplied solely by the battery 2a, 2b with the highest state of charge (SoC), one or more other batteries support the discharge, so that no single battery 2a, 2b exceeds the maximum current value without battery 2a, 2b deterioration. Once all batteries 2a, 2b are balanced (same state of charge (SoC)), they all contribute the same power.

[0066] If the priority is maximizing vehicle performance, power delivery to the vehicle takes precedence. Unlike the previous functionality, the maximum current value can be exceeded without battery degradation (2a, 2b) if necessary to achieve the required power.

[0067] If user convenience for recharging is the priority, the battery 2a and 2b with the lower state of charge (SoC) is discharged first so the user can remove and charge it (for example, at home), while maintaining an adequate discharge of batteries 2a and 2b to avoid reducing their lifespan. This way, one battery 2a and 2b will be more fully discharged and charged, while the other battery(ies) with a higher charge will remain in the vehicle.

[0068] Preferably, the power distribution system 8 also comprises a communications unit 83 configured to communicate with the vehicle's main control unit and other systems included therein, a memory unit 81 in which data relating to the operation and functioning of the power distribution system 8, as well as incidents during operation, are stored, and sensor means 82 through which the power distribution system 8 acquires the parameters on which it relies to execute the method of operation.

[0069] Figure 8 shows a first embodiment of the power distribution system 8. In this first embodiment of the power distribution system 8, all connection modules 4a, 4b comprise a respective electrical power management module 1a, 1b.

[0070] Figure 9 shows a second embodiment of the power distribution system 8. In this second embodiment, a connection module 4a lacks the electrical power management module. In this second embodiment, in the connection module 4a lacking the electrical power management module, the first connection interface 40a is directly connected to the second connection interface 41b, such that this connection module 4a permanently connects the corresponding battery 2a to the power bus 3. In other possible embodiments, the connection module lacking the electrical power management module may include a switch or similar element to interrupt the connection between the first and second connection interfaces of this connection module. This configuration allows for the omission of one of the electrical power management modules, resulting in a more cost-effective solution.

[0071] The invention also relates to a method for controlling a power distribution system 8 as described in the second aspect of the invention.

[0072] In the case of a power distribution system 8 in which all connection modules 4a, 4b comprise a respective electrical power management module 1a, 1b, the method comprises the following steps: a step in which, based on the state of charge of the batteries 2a, 2b and based on one or more of the following criteria: battery longevity, maximization of vehicle performance, user recharging convenience, etc., the batteries 2a, 2b to be connected to the power bus 3 are determined; a step in which the bus voltage Vb is established USwhich will correspond to the battery voltage Vbat of at least one of the batteries to be connected 2a, 2b, and the working parameters of the DC-DC converters of the power modules 1a, 1b corresponding to the batteries 2a, 2b to be connected and whose battery voltage Vbat has a difference with the established bus voltage Vb are calculated US that exceeds the preset threshold value Y, and a stage in which the DC-DC converter(s) of batteries 2a, 2b to be connected and whose battery voltage Vbat has a difference with the bus voltage Vb US The established value that does not exceed the preset Y threshold value is connected to power bus 3 in pass-thru mode, and the rest of the batteries 2a, 2b to be connected are connected to power bus 3 with the corresponding DC-DC converter in buck, boost or buck boost mode operating with the defined working parameters.

[0073] In the case of a power distribution system 8 in which one of the connection modules 4a, 4b lacks a respective electrical power management module 1a, 1b, the method comprises the following steps: a step in which the bus voltage Vb is established USwhich corresponds to the battery voltage Vbat whose connection module 4a lacks an electrical power management module, a stage in which, depending on the state of charge of the batteries 2b and on one or more of the following criteria: battery longevity, maximization of vehicle performance, user recharging convenience, etc., the remaining batteries 2b to be connected to the power bus 3 are determined if deemed necessary, a stage in which the working parameters of the DC-DC converters of the power modules 1a, 1b corresponding to the batteries 2b to be connected and whose battery voltage Vbat has a difference with the bus voltage Vb are calculated US established that exceeds the preset threshold value Y, and a stage in which the DC-DC converter(s) of the batteries 2b to be connected and whose battery voltage Vbat has a difference with the bus voltage Vb USThe established value that does not exceed the preset Y threshold value is connected to power bus 3 in pass-thru mode, and the rest of the 2b batteries to be connected are connected to power bus 3 with the corresponding DC-DC converter in buck, boost or buck-boost mode operating with the defined working parameters.

[0074] Another aspect of the invention relates to a power unit 9 for a vehicle.

[0075] Figure 10 shows a simplified schematic of an embodiment of the power unit 9 of the invention.

[0076] The power unit 9 comprises a plurality of battery cells 20 connected in series or in parallel, and a battery management system BMS 90 contained within a housing 94. The power unit 9 also comprises an electrical power management module 1 as described in the first aspect of the invention integrated into the battery management system BMS 90.

[0077] As shown in Figure 12, power unit 9 is configured for use with other similar power units 9 to form a system for supplying power to a vehicle's power bus 3. These power units 9 can be connected simultaneously to power bus 3 if the vehicle's power requirements so demand. This system controls and allows power units 9 with different states of charge and open-circuit voltages to be connected in parallel to the same power bus 3, enabling the power units 9 to supply power and energy simultaneously, even if they have different states of charge.The various power units 9 are configured to communicate with each other via a communications bus 93, so that the power units 9 can know the SoC state of charge, voltages and currents of the rest of the vehicle's power units 9, constituting a distributed computing system that harmoniously controls the power contribution of each power unit 9 to the power bus 3.

[0078] Figure 11 shows in detail an example of the BMS 90 battery management unit of power unit 9 in Figure 10.

[0079] The battery management system BMS 90 of Figure 11 comprises, in addition to the electrical management module 1, a control unit 95 comprising, for example, a microprocessor or programmable microcontroller with the instructions for controlling the power unit 9, a communications unit 96 configured to establish communication with the control unit 95 and to transmit and receive information from other power units 9 of the vehicle by means of a communications bus 93, and a memory 97 that allows saving the program instructions, as well as system operating data.

[0080] The battery management unit BMS 90 of Figure 11 also comprises a first connection interface 98 with the plurality of battery cells 20, said first connection interface 98 being a system called AFE (Analog Front End) that is configured to individually sensorize each cell (measuring current, voltage, and temperature) and to ensure that the plurality of battery cells 20 remain balanced. Said battery management unit BMS 90 also comprises a second connection interface 91 configured to connect to the power bus 3 of a vehicle, and a third connection interface 92 configured to connect to a communication bus 93 so that the battery management unit BMS 90 can communicate with other battery management units BMS 90 of other power units 9 of the same vehicle.This communication transmits data such as the state of charge (SoC) of the n interconnected power units 9, the voltage (Vbat) of each power unit 9, and the current supplied or received by each power unit 9. System control is implemented using distributed computing, where the different power units 9 communicate via a communication bus 93. This communication forms the basis for synchronization, ensuring the correct operation of several power units 9 in the same vehicle. Preferably, the communication bus 93 is a CAN bus.

[0081] A final aspect of the invention relates to an electric vehicle.

[0082] In one embodiment the electric vehicle comprises a power bus 3, a plurality of batteries 2, 2a, 2b, 2n, and a power distribution system 8 as described above and configured to connect the batteries 2, 2a, 2b, 2n to the power bus 3.

[0083] In another embodiment, the electric vehicle comprises a power bus 3 and a plurality of power units 9 as described above connected to said power bus 3. The power units 9 are interconnected by means of a communication bus 93. Preferably, the power bus 3 of the electric vehicle supplies a motor 6 of said electric vehicle. More preferably, the power bus 3 is connected to an inverter 5 that supplies said motor 6. Preferably, the power bus 3 is also configured to connect to a charger 7 that allows charging the vehicle's batteries 2, 2a, 2b, and 2n.

Claims

CLAIMS 1. An electrical power management module configured to provide power between a battery (2, 2a, 2b, 2n) of an electric vehicle and a power bus (3) of said vehicle, the electrical power management module (1, 1a, 1b) comprising a DC-DC converter whose input (10) is configured to connect to a battery (2, 2a, 2b, 2n) of the vehicle, and whose output (11) is configured to connect to a power bus (3) of the vehicle, the DC-DC converter being configured to provide power when the voltage of the power bus (Vb) US ) is greater than the battery voltage (Vbat), characterized in that the DC-DC converter is configured to supply power also when the power bus voltage (Vb) US) is less than the battery voltage (Vbat), the DC-DC converter being a non-isolated bidirectional buck-boost converter without series-connected capacitive elements, and the DC-DC converter being configured to work either in buck mode, in boost mode or in buck-boost mode if the difference between the battery voltage (Vbat) and the power bus voltage (Vb) US ) exceeds a preset threshold value (Y), i in pass-thru mode if the difference between the battery voltage (Vbat) and the power bus voltage (Vb) US ) is lower than the preset threshold value (Y).

2. Electrical power management module according to claim 1, wherein the DC-DC converter has a topology “4-switch bidirectional buck-boost converter”, “multi-level 4-switch bidirectional Buck-boost converter”, “interleaved 4-switch bidirectional buck-boost converter”, or a variant of any of the aforementioned topologies.

3. Electrical power management module according to claim 1 or 2, wherein when the DC-DC converter operates in buck mode, boost mode, or buck-boost mode, the control of said DC-DC converter is performed based on a current control algorithm and wherein the voltage at the input and output of the DC-DC converter is not controlled, the control algorithm establishing a reference current (l re f) that has to supply / receive the battery (2, 2a, 2b, 2n) to / from the power bus (3), and comparing the control algorithm to said reference current l re f with the current (lout) received / provided by the power bus (3) from / to the battery (2, 2a, 2b, 2n) through the DC-DC converter.

4. Electrical power management module according to claim 3, wherein the control algorithm uses a mixed analog-digital control to implement the current control algorithm, by digitally generating the reference current l re t, and analog control of the output current l ou t, so that it allows the operation of the electrical power management module at high switching frequencies with lower sampling frequencies than pure digital control.

5. Electrical power management module according to claim 4, wherein the analog control of the output current l ou t is based on a peak and valley current control algorithm.

6. A power distribution system for an electric vehicle comprising N batteries (2a, 2b, 2n) and a power bus (3), the power distribution system (8) comprising N connection modules (4a, 4b), each connection module (4a, 4b) comprising a first connection interface (40a, 40b) configured to connect to a respective battery (2a, 2b) of the vehicle, and a second connection interface (41a, 41b) configured to connect to the power bus (3) of the vehicle, at least N-1 of said connection modules (4a, 4b) comprising an electric power management module (1a, 1b) according to any of claim 1 or 5, such that each of said connection modules (4a, 4b) can connect the respective battery (2a, 2b) to the power bus (3) by operating the corresponding DC-DC converter in buck, boost, buck-boost or pass-thru, allowing the power distribution system (8) to flow energy between several batteries (2a,2b) and the power bus (3) at the same time., 7. Power distribution system according to claim 6, comprising a control unit (80) configured to decide which of the vehicle's batteries (2a, 2b) will be connected to the vehicle's power bus (3) via the corresponding connection modules (4a, 4b) and to determine the operating parameters of the control algorithms of the power modules (1a, 1b) of said connection modules (4a, 4b), said operating parameters being determined based on one or more of the following criteria: battery longevity, maximization of the Vehicle features, user charging convenience, etc.

8. Power distribution system according to claim 6 or 7, wherein all connection modules (4a, 4b) comprise a respective electrical power management module (1a, 1b).

9. Power distribution system according to claim 6 or 7, wherein a connection module (4a) lacks the electrical power management module.

10. Power unit for an electric vehicle and configured to connect to a power bus (3) of said vehicle, said power unit (9) comprising a plurality of battery cells (20) connected in series or in parallel and a battery management system (BMS), (90) an electric power management module (1) according to any of claims 1 to 5 being integrated into the battery management system (BMS) (90).

11. Power unit according to claim 10, wherein the battery management system BMS (90) also comprises a control unit (95), a communications unit (96), a first connection interface (98) with the plurality of battery cells (20), a second connection interface configured to connect to the power bus (3) of a vehicle, and a third connection interface (92) configured to connect to a communications bus (93) so that said battery management unit BMS 90 can communicate with other battery management units BMS (90) of other power units (9) of the same vehicle.

12. Electric vehicle comprising a plurality of batteries (2, 2a, 2b, 2n), a power bus (3), and a power distribution system (8) according to any of claims 6 to 9 configured to connect the batteries (2, 2a, 2b, 2n) to the power bus (3).

13. Electric vehicle comprising a power bus (3) and a plurality of power units (9) according to claim 10 or 11 connected to said power bus (3), the power units (9) being interconnected by means of a communication bus (93).

14. Method for controlling a power distribution system according to claim 8, the method comprising the following stages: a stage in which, based on the state of charge of the batteries and on one or more of the following criteria: battery longevity, maximization of vehicle performance, user recharging convenience, etc., the batteries (2a, 2b) to be connected to the power bus (3) are determined; a stage in which the bus voltage (Vb) is established US) which will correspond to the battery voltage (Vbat) of at least one of the batteries to be connected (2a, 2b), and the working parameters of the DC-DC converters of the power modules (1a, 1b) corresponding to the batteries (2a, 2b) to be connected and whose battery voltage (Vbat) has a difference with the bus voltage (Vb) are calculated US ) established that exceeds the preset threshold value (Y), and a stage in which the DC-DC converter(s) of the batteries (2a, 2b) to be connected and whose battery voltage (Vbat) has a difference with the established bus voltage (Vbus) that does not exceed the preset threshold value (Y) are connected to the power bus (Vb US ) in pass-thru mode, and the rest of the batteries (2a, 2b) to be connected are connected to the power bus (3) with the DC-DC converter in buck, boost or buck boost mode working with the defined working parameters.

15. Method for controlling a power distribution system according to claim 9, the method comprising the following stages: a stage in which the bus voltage (Vbus) is established which corresponds to the battery voltage (Vbat) whose connection module (4a) lacks an electrical power management module, a stage in which, depending on the state of charge of the batteries (2b) and depending on one or more of the following criteria: battery longevity, maximization of vehicle performance, user recharging convenience, etc.It is determined in case it is considered necessary the rest of the batteries (2b) to be connected to the power bus (3), a stage in which the working parameters of the DC-DC converters of the power modules (1a, 1b) corresponding to the batteries (2b) to be connected and whose battery voltage (Vbat) has a difference with the established bus voltage (Vbus) that exceeds the pre-established threshold value (Y) are calculated, and a stage in which the DC-DC converter(s) of the batteries (2b) or the batteries to be connected and whose battery voltage has a difference with the voltage. The established bus that does not exceed the preset threshold value (Y) is connected to the power bus (3) in pass-thru mode, and the rest of the batteries (2b) to be connected are connected to the power bus with the DC-DC converter in buck, boost or buck-boost mode operating with the defined working parameters.

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