RU2795552C1 - System and method for charging electric vehicles - Google Patents

Abstract

FIELD: electric motor construction.

SUBSTANCE: reconfigurable traction-charging system and a method for its implementation. The system is located in an electrical device with a rechargeable battery and it consists of: an electric motor, an inverter, an output rectifier, a configurator, a controller. The electric motor consists of a stator having teeth and windings wound around a plurality of stator teeth. The stator winding on at least one tooth is divided into two or more coils. The inverter contains the power switches of devices. The configurator contains contactors connected to the stator windings and power switching devices. The controller operates the power switching devices and a plurality of contactors to configure the system for operation in both traction and charge modes. In traction mode: the rechargeable battery supplies power energy to the electric motor through an inverter, the coils are connected in series. In charge mode: the connections associated with the power switching devices and the stator windings are configured to generate electrical power by the charger from an external power source to charge a rechargeable battery, the coils are connected in parallel.

EFFECT: implementation of a reconfigurable traction-charging system.

16 cl, 46 dwg

Description

Cross-references to related applications

[0001] This application claims benefit over U.S. Provisional Application 62/986,232, filed March 6, 2020, which is incorporated herein by reference in its entirety.

State of the art

1. Field of technology to which the invention belongs

[0002] This teaching generally refers to electrical devices. More specifically, the present teaching relates to methods and systems for charging batteries used in electrical devices.

2. State of the art

[0003] Electric vehicles are becoming more common, given the growing market share of vehicles on the road. However, the widespread use of electric vehicles still faces some challenges. In particular, an electric vehicle relies on batteries as its sole source of electricity, so the batteries must be recharged. Charging batteries for electric vehicles has traditionally required special external equipment, which is known as electric vehicle power equipment (EVSE, sometimes referred to as conductive charging systems or electric vehicle charging stations).

[0004] There are two main types of EVSE. One type provides alternating current (AC) electricity to the vehicle, with the vehicle's on-board charger converting the AC electricity to direct current (DC) electricity needed to charge the batteries. An AC-based EVSE works as an intermediary between an electric vehicle and an AC outlet, typically using household AC power as input power. The actual charger is provided inside the vehicle and usually has a limited power capacity. As such, electric vehicles are generally only equipped with on-board chargers with a load capacity of no more than 10 kW (eg 6 or 7 kW). If the user wishes to use a higher level of electricity, the user needs to charge the vehicles through a different type of EVSE, i.e. EVSE with DC power output or DC based EVSE.

[0005] DC-based EVSEs are also known as "fast chargers". The DC EVSE can convert AC power to DC power and thus can bypass an on-board charger on an electric vehicle to charge DC power directly to a battery. As such, the charge operation is not limited by the onboard charger's load capacity, the batteries can be charged at a much faster rate. Due to the fact that DC EVSEs are technologically more complex and costly than AC EVSEs and require high power power points, there are therefore far fewer applications compared to AC EVSEs. Such charging speed issues, combined with the limited available vehicle charging stations, are still an obstacle to the more widespread use of electric vehicles.

[0006] Thus, there is a need to develop more efficient means and methods for charging electric vehicle batteries that overcome such shortcomings.

The essence of the invention

[0007] The doctrine disclosed in this document relates to methods and systems for charging batteries used in electrical devices. More specifically, the present teaching relates to methods and systems for reconfigurable operation in one of the operating modes of thrust and charge.

[0008] The example discloses a reconfigurable traction-charging system found in an electronic device having a rechargeable battery. The system contains an electric motor, an inverter, an output rectifier, a configurator and a controller. The electric motor includes a stator that has a plurality of stator teeth and a plurality of stator windings wound around a plurality of stator teeth. The inverter contains a plurality of power switching devices. The configurator contains a plurality of contactors connected to a plurality of stator windings and a plurality of power switching devices. The controller controls a plurality of power switching devices and a plurality of contactors so as to configure the system to operate in one of a drive mode and a charge mode.

[0009] In another example, a method for implementing a reconfigurable traction-charging system located in an electrical device having a rechargeable battery is disclosed. The system is configured, via the configurator, under the control of the controller, to operate in traction mode. When a rechargeable battery charge request is received, the system is configured via the configurator to operate in charge mode. When it is determined that the criterion associated with the rechargeable battery is satisfied, the system is configured via the configurator to operate in thrust mode. In addition to the configurator and controller, the system contains an electric motor, an inverter and an output rectifier. The electric motor includes a stator that has a plurality of stator teeth and a plurality of stator windings wound around a plurality of stator teeth. The inverter contains a plurality of power switching devices. The configurator contains a plurality of contactors connected to a plurality of stator windings and a plurality of power switching devices.

[0010] Additional new features will be set forth in part in the description that follows, and in part will become apparent to those skilled in the art upon examination of the following and accompanying drawings, or may be learned through manufacture or operation of the examples. New features of the present teachings can be implemented and obtained in practice or using various aspects of the methodologies, tools and combinations outlined in the detailed examples discussed below.

Brief description of the drawings

[0011] The systems and methods disclosed herein are further described based on exemplary embodiments. These exemplary embodiments are described in detail with reference to the drawings. Embodiments are non-limiting exemplary embodiments in which like reference numerals represent like constructions throughout the multiple views of the drawings, and in which:

[0012] FIG. 1 shows an exemplary simplified circuit diagram relating to the charging electric power conceptual path according to an exemplary embodiment of the present teaching;

[0013] FIG. 2A shows an exemplary schematic drawing relating to an onboard propulsion system in accordance with an exemplary embodiment of the present exercise;

[0014] FIG. 2B shows an exemplary schematic drawing related to an onboard propulsion system in accordance with an exemplary embodiment of the present exercise;

[0015] FIG. 3 shows an exemplary design of windings wound around motor stator teeth in accordance with an exemplary embodiment of the present teaching;

[0016] FIG. 4A shows an exemplary schematic drawing relating to an onboard propulsion system in accordance with an exemplary embodiment of the present exercise;

[0017] FIG. 4B shows an exemplary simplified circuit diagram relating to the charging electrical path of an onboard charge-and-propulsion system, in accordance with an exemplary embodiment of the present teaching;

[0018] FIG. 4C shows an exemplary simplified circuit diagram relating to the traction power path of an onboard traction and charge system, in accordance with an exemplary embodiment of the present teaching;

[0019] FIG. 4D shows an exemplary schematic drawing relating to an onboard charge/propulsion system in accordance with an exemplary embodiment of the present exercise;

[0020] FIG. 4E shows an exemplary simplified circuit diagram relating to the charging electrical path of an onboard charge/propulsion system, in accordance with an exemplary embodiment of the present teaching;

[0021] FIG. 4F shows an exemplary simplified circuit diagram relating to the traction power path of an onboard traction and charge system, in accordance with an exemplary embodiment of the present teaching;

[0022] FIG. 5A shows an exemplary schematic drawing relating to an onboard propulsion system in accordance with an exemplary embodiment of the present exercise;

[0023] FIG. 5B shows an exemplary schematic drawing relating to an onboard propulsion system in accordance with an exemplary embodiment of the present exercise;

[0024] FIG. 6A shows an exemplary simplified circuit diagram related to an onboard propulsion system in accordance with an exemplary embodiment of the present exercise;

[0025] FIG. 6B shows an exemplary simplified circuit diagram related to an onboard propulsion system in accordance with an exemplary embodiment of the present exercise;

[0026] FIG. 6C shows an exemplary simplified circuit diagram relating to an onboard propulsion system in accordance with an exemplary embodiment of the present exercise;

[0027] FIG. 7A shows an exemplary schematic drawing relating to an onboard propulsion system in accordance with an exemplary embodiment of the present exercise;

[0028] FIG. 7B shows an exemplary schematic drawing relating to an onboard charge/propulsion system in accordance with an exemplary embodiment of the present exercise;

[0029] FIG. 8A shows an exemplary simplified circuit diagram related to an onboard propulsion system in accordance with an exemplary embodiment of the present exercise;

[0030] FIG. 8B shows an exemplary simplified circuit diagram related to an onboard propulsion system in accordance with an exemplary embodiment of the present exercise;

[0031] FIG. 8C shows an exemplary simplified circuit diagram relating to an onboard charge/propulsion system in accordance with an exemplary embodiment of the present exercise;

[0032] FIG. 9A shows an exemplary schematic drawing relating to an onboard propulsion system in accordance with an exemplary embodiment of the present exercise;

[0033] FIG. 9B shows an exemplary schematic drawing relating to an onboard propulsion system in accordance with an exemplary embodiment of the present exercise;

[0034] FIG. 10A shows an exemplary simplified circuit diagram relating to an onboard propulsion system in accordance with an exemplary embodiment of the present exercise;

[0035] FIG. 10B shows an exemplary simplified circuit diagram related to an onboard propulsion system in accordance with an exemplary embodiment of the present exercise;

[0036] FIG. 10C shows an exemplary simplified circuit diagram related to an onboard propulsion system in accordance with an exemplary embodiment of the present exercise;

[0037] FIG. 11A shows an exemplary schematic drawing related to an onboard propulsion system in accordance with an exemplary embodiment of the present exercise;

[0038] FIG. 11B shows an exemplary schematic drawing relating to an onboard propulsion system in accordance with an exemplary embodiment of the present exercise;

[0039] FIG. 12A shows an exemplary simplified circuit diagram related to an onboard traction and charge system in accordance with an exemplary embodiment of the present exercise;

[0040] FIG. 12B shows an exemplary simplified circuit diagram related to an onboard traction and charge system in accordance with an exemplary embodiment of the present exercise;

[0041] FIG. 12C shows an exemplary simplified circuit diagram relating to an onboard propulsion system in accordance with an exemplary embodiment of the present exercise;

[0042] FIG. 13 shows an exemplary flowchart related to the operation of an onboard propulsion system, in accordance with an exemplary embodiment of the present exercise;

[0043] FIG. 14 shows an exemplary schematic drawing related to the pre-charge of the capacitor C1 according to an exemplary embodiment of the present teaching;

[0044] FIG. 15A shows an exemplary schematic drawing relating to the hardware components of an onboard propulsion system, in accordance with an exemplary embodiment of the present exercise;

[0045] FIG. 15B shows an exemplary schematic drawing relating to the hardware components of an onboard propulsion system, in accordance with an exemplary embodiment of the present teaching;

[0046] FIG. 16 shows an exemplary schematic drawing relating to a connection between a charge/traction controller and power switching devices, in accordance with an exemplary embodiment of the present teaching;

[0047] FIG. 17 shows an exemplary control scheme performed in charge mode of an onboard charge/propulsion system, in accordance with an exemplary embodiment of the present exercise;

[0048] FIG. 18A-18G show exemplary schematic drawings relating to various connections of more than one electric motor and/or more than one battery of an onboard propulsion system, in accordance with exemplary embodiments of the present exercise;

[0049] FIG. 19 shows an exemplary schematic drawing relating to connections of two or more inverter chargers and a battery, in accordance with an exemplary embodiment of the present teaching;

[0050] FIG. 20A shows an exemplary simplified circuit diagram relating to an onboard traction and charge system in accordance with an exemplary embodiment of the present exercise; And

[0051] FIG. 20B shows an exemplary simplified circuit diagram related to an onboard propulsion system in accordance with an exemplary embodiment of the present exercise.

Detailed description of the invention

[0052] In the following detailed description, numerous specific details are set forth as examples in order to provide a thorough understanding of the relevant teachings. However, it should be apparent to those skilled in the art that the present teachings may be used in practice without such details. In other cases, well-known methods, procedures, components, circuits, layouts, and/or control strategies have been described at a relatively high level, without much detail, in order to avoid unnecessarily obfuscating aspects of the present teachings.

[0053] The present teaching is aimed at improving the current state of the art in charging rechargeable batteries. In particular, the present teaching discloses an integrated, reconfigurable, on-board propulsion and charge solution that can find application in electrical applications (including, for example, electric vehicles, dedicated electric vehicles, etc.).

[0054] The onboard traction-charging system disclosed in this exercise includes a combination of reconfigurable phase motor windings and inverters. When operating in traction mode, the system operates as a traction mechanism that is adapted to provide mechanical power to a load, and in charge mode, it operates as an on-board charger that is adapted to charge the battery or batteries included in the vehicle at high power. On the one hand, it is possible to perform recharging quickly with a high power switching power supply; on the other hand, the cost of installing a plurality of EVSEs (or charging stations) that supply electrical AC power to the onboard traction/charging system can be significantly reduced.

[0055] The onboard traction/charging system of the present teaching takes full advantage of two previously existing components in electric vehicles: an electric motor with stator windings, and a polyphase inverter with power switching devices. The switching mechanism, referred to as the configurator in this document, changes the connections of the stator windings and power switching devices included in the inverter to allow switching between the two modes of operation. When the on-board traction and charging system is in traction mode, the power switching devices constitute an inverter that converts the DC power output from the battery into the corresponding AC voltage so as to drive the motor to provide torque (positive or negative) to drive the vehicle. This torque can either transfer energy from the battery or recover energy in dynamic braking mode. When the onboard traction/charging system is in charge mode, the configurator reconfigures the connection of the inverter and motor windings to form one or more input stages (with or without rectification, boost, and/or power factor correction (PFC)), and one or more more fully isolated DC/DC converter output stages so as to implement a fully isolated onboard charger.

[0056] FIG. 1 shows, in a simplified form, the conceptual path of charging electricity in accordance with the example of this exercise. To facilitate understanding, details belonging to shared components associated with charge and thrust modes are not shown in the simplified circuit diagram in FIG. 1.

[0057] As shown in FIG. 1, the charging power path comprises an input bridge rectifier or a passive rectifier input stage D1 that is electrically connected to a single-phase AC power input or a multi-phase AC power input. The boost converter is used to increase the DC voltage output from the input bridge rectifier or the input stage D1 of the passive rectifier to a regulated DC link voltage. The boost converter includes a boost inductor L1, a power switching device Q1 and a power switching device Q2. The adjusted DC_LINK voltage output from the boost converter is applied to a bridge converter containing two half-bridges (Q3 and Q4; Q5 and Q6). The output of the bridge converter energizes the transformer T1 and in turn the output bridge rectifier D2 to produce isolated DC power to charge the battery. Inductor L2 and capacitor C2 are used to filter and smooth the DC power output from the output bridge rectifier D2.

[0058] As discussed above, although not shown in FIG. 1, the charging power path can share a plurality of components with the traction power path. The idea of sharing components will be described in detail below with reference to the accompanying drawings. The degree of component sharing between charge and thrust modes may vary depending on design details. The accompanying drawings illustrate various ways of implementing the inventive ideas and concepts disclosed in this teaching.

First Embodiment

[0059] FIG. 2A shows a schematic drawing related to an onboard traction system according to the first embodiment. In FIG. 2A, some of the coils used to build the charge mode transformer are connected in parallel when the system is in traction mode. Fig. 2B shows another schematic drawing related to an onboard traction system according to the first embodiment. In FIG. 2B, some of the coils used to build the charge mode transformer are connected in series when the system is in pull mode.

[0060] With the exception of the difference in the connection of the coils (parallel or series in thrust mode), the airborne charge-and-propulsion systems shown in FIG. 2A and 2B both contain a polyphase motor, a rechargeable battery, an inverter, an input rectifier, an output rectifier, a configurator, and a plurality of contactors. A polyphase motor may contain three or more stator winding phases. In some applications, alternatively, the motor may be a two-phase motor driven by two sets of half bridges. The inverter includes a plurality of power switching devices SW1, SW2, SW3, SW4, SW5 and SW6, and serves to drive a multi-phase motor. Power switching devices can have different current carrying capacities. For example, depending on the output electrical power level and/or input voltage condition, the power switching devices SW3 and SW4 that are used to form the boost converter in charge mode may have a higher current carrying capacity compared to the current carrying capacity of SW1, SW2, SW5 and SW6. Depending on whether the input power is from a single-phase or multi-phase power source, the input rectifier can be a single-phase or multi-phase bridge rectifier. When a DC power source is used to supply charging power, the input rectifier can be omitted. The configurator contains a number of contactors K1, K2, K3, K4, K5, K6, K7, K8, K9 and K10. When properly controlled, the configurator serves to reconfigure the connections of the various components, in particular the connections between windings and/or power switching devices SW1, SW2, SW3, SW4, SW5 and SW6, in order to switch the system between different operating modes. A set of contactors K1 and K2 can be used to connect and disconnect the positive and negative terminals of a rechargeable battery. More specifically, contactors K1 and K2 are open in charge mode and closed in pull mode. The contactor kit K3 and K4 can be used to connect and disconnect the rectified DC power from the input AC power. Contactors K3 and K4 are closed in charge mode and open in pull mode.

[0061] In addition, the systems shown in FIG. 2A and 2B may further comprise an input filter and/or an output filter that can be used to reduce noise and voltage or current ripple. These input and output filters may include, but are not limited to, chokes and/or capacitors. Capacitor C1 can be connected to the input side of the inverter. Although the capacitor C1 is shown as the only one, there may also be a plurality of capacitors or a module with a plurality of capacitors assembled together. As an example of an output filter, inductor L1 and capacitor C2 are shown in FIG. 2A and 2B. Although the output capacitor C2 is shown as the only one, there may also be a plurality of capacitors or a module with a plurality of capacitors assembled together. Although the output capacitor C2 is shown as the only one, there may also be a plurality of capacitors or a module with a plurality of capacitors assembled together. Alternatively, if the battery is adapted to accept a ripple current on the output side of the output bridge rectifier, capacitor C2 may be omitted.

[0062] Although not shown in FIG. 2A and 2B. other circuit protection components may be included in the system including, but not limited to, pre-charge circuits, discharge circuits, inrush protection circuits, and so on.

[0063] As discussed above, both airborne charge/propulsion systems illustrated in FIG. 2A and 2B may be configured to operate in one of two operating modes, i.e. charge mode and thrust mode. Details relating to the configuration will be described below with reference to FIG. 4A-F.

[0064] Referring now to FIG. 3, which shows an exemplary structure of windings wound on the stator teeth of an electric motor in accordance with the example of this exercise. For example, the motor may be an 18 tooth, 6 pole pair, 3-phase permanent magnet synchronous motor (PMSM) in which the winding on at least one tooth of the motor stator is split into two or more coils. As illustrated by way of example in FIG. 3, two sets of windings are on each of phase A and phase C prongs, while one set of windings is on phase B prong. The separated windings have separate terminals that must be reconfigured into different connections. As such, the magnetic components in the conceptual charge path illustrated in FIG. 1 and the charging systems illustrated in association with FIG. 2A and 2B may be implemented with windings wound around the motor stator teeth. For example, as shown in FIG. 3, the winding on phase A tooth is divided into coil A and coil D, and the winding on phase C tooth is divided into coil C and coil E. Coils A, C, D and E form a transformer when the onboard traction system is in charge. A separate winding, coil B, can be used as a step-up choke in charge mode with contactor K5 open and as a phase winding in pull mode with contactor K5 closed. Alternatively, the boost function can be implemented with a separate choke instead of coil B, by modification in the circuit connections (eg contactor K5 is no longer needed in this situation).

[0065] FIG. 4A shows a schematic drawing relating to an onboard traction system as illustrated in FIG. 2A, wherein the open/close state of the contactors is controlled so that the system operates in charge mode. In FIG. 4A contactors K3, K4, K9 and K10 are closed and K1, K2, K5, K6, K7 and K8 are open. Accordingly, the charging electric path is constructed as shown in FIG. 4b. In order to avoid unnecessary confusing aspects of this teaching, the contactors are not shown in the simplified circuit diagram in FIG. 4b.

[0066] In order to configure the onboard charge/propulsion system as illustrated in FIG. 2A, in pull mode, contactors K1, K2, K5, K6, K7 and K8 close and K3, K4, K9 and K10 open. Accordingly, the traction power path is constructed as shown in FIG. 4C. In the operating mode shown in Fig. 4C, all windings that are seated on the same tooth are connected in parallel. Essentially, coil A and coil D together form phase A, coil C and coil E together form phase C, and coil B forms phase B on its own. In order to avoid unnecessary confusing aspects of this teaching, the contactors are not shown in the simplified circuit diagram in FIG. 4C.

[0067] FIG. 4D shows a schematic drawing relating to an onboard charge/propulsion system as illustrated in FIG. 2B, wherein the open/close state of the contactors is controlled so that the system operates in charge mode. In FIG. 4D contactors K3, K4, K7, K9 and K10 are closed and K1, K2, K5, K6 and K8 are open. Accordingly, the charging electric path is constructed as shown in FIG. 4E. In order to avoid unnecessary confusing aspects of this teaching, the contactors are not shown in the simplified circuit diagram in FIG. 4E.

[0068] Similarly, in order to configure the system as shown in FIG. 2B, in pull mode, contactors K1, K2, K5, K6 and K8 close and K3, K4, K7, K9 and K10 open. Accordingly, the traction power path is constructed as shown in FIG. 4F. All windings that are seated on the same tooth are connected in series. In this case, coil A and coil D together form phase A, coil C and coil E together form phase C, and coil B forms phase B on its own. In order to avoid unnecessary confusing aspects of this teaching, the contactors are not shown in the simplified circuit diagram in FIG. 4F.

[0069] When the on-board propulsion system is configured in propulsion mode, the rechargeable battery can supply DC power to the polyphase inverter. Then, the inverter can convert DC power into AC power and drive the polyphase motor. Here, a traditional three-phase motor drive can be used. In a typical electric vehicle application where a permanent magnet motor is used, a sensor may be provided to measure the position of the rotor so as to control the motor to achieve the desired performance, especially when the shaft speed is low. Generally, the power switching devices used in the onboard traction charge inverter may be IGBT or FET devices driven by vector control methods under the control of a processor (such as DSP, FPGA, etc.). To perform vector control, current sensors may also be placed with respect to at least two phases to detect the phase current to be adjusted by the processor.

[0070] When the system is configured in charge mode, a fully isolated two-stage charger is provided that contains an input stage (with or without a boost function and/or PFC) and a DC/DC output stage. The input stage can be built using an input bridge rectifier. Additionally, the motor stator coil B can act as a boost choke, with power switch SW4 as boost switch, power switch parasitic diode SW3 as flyback diode, and capacitor C1 as output capacitor. Alternatively, if the system is operated with the power switching device SW4 always off, the front end is configured as a simple rectifier. The inductance of coil B can help smooth the current to some extent; typically, it is quite small in order to achieve a high power factor.

[0071] If the mains AC input is supplied from a single-phase or split-phase power supply, the step-up stage can also perform a power factor correction (PFC) function. In this situation, the input voltage is measured and the input current is shaped to follow the shape of the sinusoidal input voltage. With this approach, a high power factor (eg more than 0.99) can be achieved. At least one input current sensor may be provided to perform this function. Also, in the PFC approach, the intermediate voltage (DC link voltage) across capacitor C1 may need to be higher than the peak input voltage to enable current regulation. For example, for a 240 Vrms line, the DC link voltage may need to be higher than about 400 V.

[0072] As discussed above, the phase B coil operates electrically as a separate input choke. For three-phase inputs, this single input inductor plus switch topology may not be able to force the input currents to conform to sinusoidal input voltages. However, adjusting the current in coil B to be constant helps to achieve a better power factor compared to low inductance passive rectification approaches. Typically, an improved power factor of about 0.955 can still be achieved.

[0073] As can be seen in the second DC/DC stage illustrated in FIG. 4B and 4E, the power switches SW1, SW2, SW5 and SW6 form a bridge control circuit. Note that the bridge control circuit is a buck converter. Coil A and coil C act as the primary winding of the transformer, and coil D and coil E act as the secondary winding of the transformer. Then, the bridge rectifier converts the AC power output from the secondary side of the transformer into DC power pulsing at the appropriate PWM frequency, and the inductor L1 eliminates the high frequency PWM components from the charging current output to the rechargeable battery. The output rectifier can be implemented with multiple parallel diodes or a single bridge rectifier.

Second Embodiment

[0074] In this second embodiment, the charging power is supplied from a single-phase or split-phase AC power input, and the input bridge rectifier input stage included in the charging power path has a PFC boost converter.

[0075] FIG. 5A shows a schematic drawing related to an onboard traction system according to the second embodiment. In FIG. 5A, some of the coils used to construct the charge mode transformer are connected in parallel when the system is in traction mode. Fig. 5B shows another schematic drawing related to an onboard traction system according to the second embodiment. In FIG. 5B, some of the coils used to build the charge mode transformer are connected in series when the system is in pull mode.

[0076] With the exception of the difference in the connection of the coils (in parallel or in series in the thrust mode), the on-board charging and propulsion systems shown in FIG. 5A and 5B both contain a polyphase motor, a rechargeable battery, an inverter, an input rectifier, an output rectifier, a configurator, and a plurality of contactors. A polyphase motor may contain three or more stator winding phases. In some applications, alternatively, the motor may be a two-phase motor driven by two sets of half bridges. The inverter includes a plurality of power switching devices SW1, SW2, SW3, SW4, SW5 and SW6, and serves to drive a multi-phase motor. Power switching devices can have different current carrying capacities. The input rectifier can be a single-phase bridge rectifier. The configurator contains a number of contactors K1, K2, K3, K4, K5, K6, K7, K8, K9 and K10. When properly controlled, the configurator serves to reconfigure the connections of the various components, in particular the connections between the coils A-E of the windings and/or the power switching devices SW1-6, in order to switch the system between different operating modes. A set of contactors K1 and K2 can be used to connect and disconnect the positive and negative terminals of a rechargeable battery. More specifically, contactors K1 and K2 are open in charge mode and closed in pull mode. The contactor kit K3 and K4 can be used to connect and disconnect the rectified DC power from the input AC power. Contactors K3 and K4 are closed in charge mode and open in pull mode.

[0077] In addition, the systems shown in FIG. 5A and 5B may further comprise an input filter and/or an output filter that can be used to reduce noise and voltage or current ripple. These input and output filters may include, but are not limited to, chokes and/or capacitors. Capacitor C1 can be connected to the input side of the inverter. Although the capacitor C1 is shown here as the only one, there may also be a plurality of capacitors or a module with a plurality of capacitors assembled together. As an example of output filter components, an inductor L1 and a capacitor C2 are shown in FIG. 5A and 5B. Although the output capacitor C2 is shown as the only one, there may also be a plurality of capacitors or a module with a plurality of capacitors assembled together. Alternatively, if the battery is adapted to accept a ripple current on the output side of the output bridge rectifier, capacitor C2 may be omitted.

[0078] Although not shown in FIG. 5A and 5B. other circuit protection components may be included in the system including, but not limited to, pre-charge circuits, discharge circuits, inrush protection circuits, and so on.

[0079] Referring back to FIG. 3, at least one of the windings wound around the motor stator teeth can be divided into two coils. The split windings have separate terminals that can be reconfigured into different connections to apply to different operating modes, i.e. charge mode and thrust mode. In order to configure the onboard charge/propulsion system, which is illustrated in FIG. 5A, in pull mode, contactors K1, K2, K5, K6, K7 and K8 close and K3, K4, K9 and K10 open. As a result, the traction power path is constructed as shown in FIG. 6A. In the operating mode shown in Fig. 6A, all windings that are seated on the same tooth are connected in parallel. Essentially, coil A and coil D together form phase A, coil C and coil E together form phase C, and coil B forms phase B on its own. Likewise, in order to configure the onboard traction and charge system as illustrated in FIG. 5B, in pull mode, contactors K1, K2, K5, K6 and K8 close and K3, K4, K7, K9 and K10 open. Accordingly, the traction power path is constructed as shown in FIG. 6b. In the operating mode shown in Fig. 6B, all coils that are seated on the same tooth are connected in series. Essentially, coil A and coil D together form phase A, coil C and coil E together form phase C, and coil B forms phase B on its own.

[0080] When the onboard propulsion system is operating in the traction mode, the rechargeable battery can supply DC power to the multi-phase inverter. Then, the inverter can convert the DC power into AC power and thus drive the polyphase motor.

[0081] In order to configure the onboard charge/propulsion system as illustrated in FIG. 5A, in charge mode, contactors K3, K4, K9 and K10 close and K1, K2, K5, K6, K7 and K8 open. In order to configure the onboard charge/propulsion system, which is illustrated in FIG. 5B, in charge mode, contactors K3, K4, K7, K9 and K10 close and K1, K2, K5, K6 and K8 open. Fig. 6C shows the charging electrical path as built, which applies to both onboard traction and charge systems shown in FIG. 5A and 5B.

[0082] When the onboard propulsion system is configured in charge mode, a fully isolated two-stage charger is provided that contains a PFC boost input stage and a fully isolated DC/DC output stage. The input stage contains an input bridge rectifier. Additionally, the motor coil B can act as a PFC boost choke, with power switch SW4 as boost switch, power switch parasitic diode SW3 as flyback diode, and capacitor C1 as output capacitor. In the DC/DC output stage, the power switching devices SW1, SW2, SW5 and SW6 form a bridge control circuit. In addition, Coil A and Coil C act as the primary winding of the transformer, while Coil D and Coil E act as the secondary winding of the transformer. The output bridge rectifier converts the AC power output from the secondary side of the transformer into DC power. Inductor L1 and output capacitor C2 are connected on the output side of the output bridge rectifier to remove ripple components in the DC power.

[0083] In this charge mode, the PFC boost front end can convert single-phase AC power from the grid to DC power while performing power factor compensation with respect to the grid. By using the input voltage as a reference for the current in the inductor of coil B, the input current can take the form of a sine wave. For example, the current feedback loop may adjust the current to follow a reference that is proportional to the input voltage, and the feedback loop may adjust the DC link voltage across capacitor C1. The control may be implemented by a separate power factor correction control IC or control processor, which will be described below with reference to FIG. 16. Then, the bridge control circuit of the second stage can receive DC power from the first stage as input, invert it into AC power, and pass the inverted AC power through a transformer formed by the motor windings, so that complete isolation is achieved. The AC power output by the transformer is applied to the output bridge rectifier and then to the output filter to generate DC power to charge the battery.

Third Embodiment

[0084] In this third embodiment, charging power is supplied from a multi-phase AC power input, and the charging power path comprises a full three-phase PFC input stage.

[0085] FIG. 7A shows a schematic drawing related to an onboard propulsion system according to the third embodiment of the present exercise. In FIG. 7A, some of the coils used to construct the charge mode transformer are connected in parallel when the system is in traction mode. Fig. 7B shows another schematic drawing related to an onboard propulsion system according to the third embodiment of the present exercise. In FIG. 7B, some of the coils used to build the charge mode transformer are connected in series when the system is in pull mode.

[0086] With the exception of the difference in the connection of the coils (parallel or series) in the thrust mode, the systems shown in FIG. 7A and 7B both contain a polyphase motor, rechargeable battery, inverter, output rectifier, configurator, and contactor kits. A polyphase motor may contain three or more stator winding phases. In some applications, alternatively, the motor may be a two-phase motor driven by two sets of half bridges. In a situation where the three-phase PFC function is executed in the charge mode, the inverter includes a plurality of power switching devices SW1, SW2, SW3a, SW3b, SW3c, SW4a, SW4b, SW4c, SW5, and SW6, and serves to drive the multi-phase motor. Power switching devices can have different current carrying capacities. The configurator contains a number of contactors K1, K2, K3, K4, K5, K6, K7, K8, K9, K10, K11, K12 and K13. When properly controlled, the configurator serves to reconfigure the connections of the various components, in particular the connections between the coils A-E of the windings and/or the power switching devices SW1-6, in order to switch between different operating modes. A set of contactors K1 and K2 can be used to connect and disconnect the positive and negative terminals of a rechargeable battery. Contactors K1 and K2 are open in charge mode and closed in pull mode. A set of contactors K3, K4 and K5 can be used to connect and disconnect from the incoming AC power. Contactors K3, K4 and K5 are closed in charge mode and open in pull mode.

[0087] In addition, the systems shown in FIG. 7A and 7B may further comprise an input filter and/or an output filter that can be used to reduce noise and voltage or current ripple. Capacitor C1 can be connected to the input side of the inverter. Although the capacitor C1 is shown here as the only one, there may also be a plurality of capacitors or a module with a plurality of capacitors assembled together. The output filter may include, but is not limited to, chokes and/or capacitors. As an example, capacitor C2 and inductor L1 are shown in FIG. 7A and 7B, which serve to smooth out the ripple voltage at the output of the rectifier in order to charge the battery. Although the output capacitor C2 is shown as the only one, there may also be a plurality of capacitors or a module with a plurality of capacitors assembled together. Alternatively, if the battery is adapted to accept a ripple current on the output side of the output bridge rectifier, capacitor C2 may be omitted.

[0088] Although not shown in FIG. 7A and 7B. other circuit protection components may be included in the system including, but not limited to, pre-charge circuits, discharge circuits, inrush protection circuits, and so on.

[0089] Similar to the first and second embodiments, at least one of the windings wound around the motor stator teeth may be divided into two or more coils. In other words, on at least one tooth of the motor stator, the winding is formed by two or more coils. Each coil has separate terminals that can be reconfigured into different connections to apply to charge mode and thrust mode. Here, the winding for phase A is divided into coil A and coil D, the winding for phase C is divided into coil C and coil E. The winding for phase B is divided into coil B1, coil B2 and coil B3, which are on separate teeth of the motor. In the example, coil B1 is wound about two teeth, coil B2 about another two teeth, coil B3 about an additional other two teeth.

[0090] In order to configure the onboard propulsion system as shown in FIG. 7A, in pull mode, contactors K1, K2, K6, K7, K8, K11, K12 and K13 close and K3, K4, K5, K9 and K10 open. Accordingly, the traction power path is constructed as shown in FIG. 8A. In the operating mode shown in Fig. 8A, coil A and coil D are connected in parallel to form phase A; coil C and coil E are connected in parallel to form phase C; and coil B1, coil B2 and coil B3 form phase B (or each of them may be a separate phase, in a situation where the motor is a five-phase motor instead of a three-phase motor).

[0091] Similarly, in order to configure the system as shown in FIG. 7B, in traction mode, contactors K1, K2, K6, K8, K11, K12 and K13 close and K3, K4, K5, K7, K9 and K10 open. Accordingly, the traction power path is constructed as shown in FIG. 8B. In the operating mode shown in Fig. 8B, coil A and coil D are connected in series to form phase A; coil C and coil E are connected in series to form phase C. In addition, coil B1, coil B2 and coil B3 form phase B (or each of them may be a separate phase). Since the coils B1-B3 are wound on the teeth of the same phase (phase B) of the electric motor, the currents in them do not create a rotating field that causes the electric motor to rotate.

[0092] When the onboard propulsion system is operating in the traction mode, the rechargeable battery can supply DC power to the polyphase inverter. Then, the inverter can convert the DC power into AC power and thus drive the polyphase motor. The plurality of central power switching devices shown in FIG. 8A and 8B switch together to act as a single half bridge. Those. power switching devices SW3a, SW3b and SW3c are turned on and off together; the power switching devices SW4a, SW4b and SW4c are switched on and off together.

[0093] In order to configure the onboard charge/propulsion system as illustrated in FIG. 7A, in charge mode, contactors K3, K4, K5, K9 and K10 close and K1, K2, K6, K7, K8, K11, K12 and K13 open. In order to configure the onboard charge/propulsion system as shown in FIG. 7B, in charge mode, contactors K3, K4, K5, K7, K9 and K10 close and K1, K2, K6, K11, K12 and K13 open. Fig. 8C shows the charging electrical path as built, which is applied to both onboard traction and charge systems shown in FIG. 7A and 7B.

[0094] When the onboard traction system is configured in charge mode, a fully isolated two-stage charger is provided that contains a full three-phase PFC boost input stage and a fully isolated DC/DC output stage. In the input stage, Coil B1, Coil B2, Coil B3 operate as step-up chokes, and power switching devices SW3a, SW3b, SW3c, SW4a, and SW4c act as step-up PFC switches. In the DC/DC output stage, the power switching devices SW1, SW2, SW5 and SW6 form a bridge control circuit. In addition, Coil A and Coil C act as the primary winding of the transformer, and Coil D and Coil E act as the secondary winding of the transformer. The output bridge rectifier converts the AC power output from the secondary side of the transformer into DC power. Inductor L1 and output capacitor C2 are connected on the output side of the output bridge rectifier to remove ripple components in the DC power.

[0095] In this charging mode, the PFC boost input stage can convert multi-phase grid power into DC power while performing power factor compensation to achieve a sinusoidal input current. Then, the bridge control circuit of the second stage can receive the DC power of the first stage as an input, invert it into AC power, and pass the inverted AC power through a transformer formed by the motor windings so that complete isolation is achieved. The AC power output by the transformer is applied to the output bridge rectifier and then to the output capacitor to form DC power, which charges the rechargeable battery.

[0096] In order to form the complete three-phase PFC front end shown in FIG. 8C, a voltage sensor is placed at the input to detect the angular position of AC at the input. A phase locked loop can be used to perform this function. When angle information representing the phase voltage of one phase (such as phase A) is obtained, the control of the switch can be realized through the conversion of dq to ABC and state vector modulation so as to determine the required drive for the power switching devices. In this scheme, one converted axis (eg d-axis) controls the power factor and the other axis (eg q-axis) controls the power flow and is used to control the intermediate voltage of the DC link bus. In addition, an internal current loop is used with respect to each axis to perform power factor compensation. At least two current sensors are required to measure the input current. However, since the total current is required in the thrust mode, three current sensors are preferred.

Fourth Embodiment

[0097] In this fourth embodiment, charging power is supplied from a single-phase power source or a single-phase split-phase power source, and the charging path comprises a single-phase or split-phase push-pull PFC input stage.

[0098] FIG. 9A shows a schematic drawing related to an onboard propulsion system according to the fourth embodiment of the present exercise. In FIG. 9A, some of the coils used to construct the charge mode transformer are connected in parallel when the system is in traction mode. Fig. 9B shows another schematic drawing related to the onboard propulsion system according to the fourth embodiment of the present exercise. In FIG. 9B, some of the coils used to build the charge mode transformer are connected in series when the system is in pull mode.

[0099] With the exception of the difference in the connection of the coils (parallel or series) in the thrust mode, the airborne charging and propulsion systems shown in FIG. 9A and 9B both contain a polyphase motor, rechargeable battery, inverter, output rectifier, configurator, and contactor kits. A polyphase motor may contain three or more stator winding phases. In some applications, alternatively, the motor may be a two-phase motor driven by two sets of half bridges. In a situation where single-phase or split-phase push-pull PFC is executed in the charge mode, the inverter includes a plurality of power switching devices SW1, SW2, SW3a, SW3b, SW4a, SW4b, SW5, and SW6, and serves to drive a multi-phase motor. Power switching devices can have different current carrying capacities. The configurator contains a number of contactors K1, K2, K3, K4, K6, K7, K8, K9, K10, K11 and K12. When properly controlled, the configurator serves to reconfigure the connections of the various components, in particular the connections between the coils A-E of the windings and/or the power switching devices SW1-6, in order to switch between different operating modes. A set of contactors K1 and K2 can be used to connect and disconnect the positive and negative terminals of a rechargeable battery. Contactors K1 and K2 are open in charge mode and closed in pull mode. A set of contactors K3 and K4 can be used to connect and disconnect from the incoming AC power. Contactors K3 and K4 are closed in charge mode and open in pull mode.

[00100] In addition, the systems shown in FIG. 9A and 9B may further comprise an input filter and/or an output filter that can be used to reduce noise and voltage or current ripple. Capacitor C1 can be connected to the input side of the inverter. Although the capacitor C1 is shown here as the only one, there may also be a plurality of capacitors or a module with a plurality of capacitors assembled together. The output filter may include, but is not limited to, chokes and/or capacitors. As an example, capacitor C2 and inductor L1 are shown in FIG. 9A and 9B, which serve to smooth out the ripple voltage at the output of the rectifier in order to power the battery. Although the output capacitor C2 is shown as the only one, there may also be a plurality of capacitors or a module with a plurality of capacitors assembled together. Alternatively, if the battery is adapted to accept a ripple current on the output side of the output bridge rectifier, capacitor C2 may be omitted.

[00101] Although not shown in FIG. 9A and 9B. other circuit protection components may be included in the system including, but not limited to, pre-charge circuits, discharge circuits, inrush protection circuits, and so on.

[00102] Similar to the first to third embodiments, at least one of the windings wound around the motor stator teeth may be divided into two or more coils. In other words, on at least one tooth of the motor stator, the winding is formed by two or more coils. The split windings have separate terminals that can be reconfigured into different connections to apply to charge mode and thrust mode. For example, the winding for phase A is divided into coil A and coil D, the winding for phase C is divided into coil C and coil E, and the winding for phase B is divided into coil B1 and coil B2.

[00103] In order to configure the onboard propulsion system as shown in FIG. 9A, in traction mode, contactors K1, K2, K6, K7, K8, K11 and K12 close and K3, K4, K9 and K10 open. Accordingly, the traction power path is constructed as shown in FIG. 10A. In the operating mode shown in Fig. 10A, coil A and coil D are connected in parallel to form phase A; coil C and coil E are connected in parallel to form phase C; and coil B1 and coil B2 form phase B (or each may be a separate phase).

[00104] Similarly, in order to configure the system as shown in FIG. 9B, in traction mode, contactors K1, K2, K6, K8, K11 and K12 close and K3, K4, K7, K9 and K10 open. Accordingly, the traction power path is constructed as shown in FIG. 10b. In the operating mode shown in Fig. 10B, coil A and coil D are connected in series to form phase A; coil C and coil E are connected in series to form phase C; and coil B1 and coil B2 form phase B (or each may be a separate phase).

[00105] When the onboard propulsion system is in traction mode, the rechargeable battery can supply DC power to the polyphase inverter. Then, the inverter can convert the DC power into AC power and thus drive the polyphase motor.

[00106] In order to configure the onboard propulsion system as shown in FIG. 9A, in charge mode, contactors K3, K4, K9 and K10 close and K1, K2, K6, K7, K8, K11 and K12 open. In order to configure the onboard charge/propulsion system as shown in FIG. 9B, in charge mode, contactors K3, K4, K7, K9 and K10 close and K1, K2, K6, K8, K11 and K12 open. Fig. 10C shows the charging electrical path as built, which is applied to both onboard traction systems shown in FIG. 9A and 9B.

[00107] When the onboard propulsion system is configured in charge mode, a fully isolated two-stage charger is provided that includes a single-phase or split-phase push-pull PFC input stage and a fully isolated DC/DC output stage. In the input stage, coil B1 and coil B2 act as PFC boost chokes, and the power switches SW3a, SW3b, SW4a, and SW4b act as full-bridge switches, controlling the flow of power and giving the input current a sinusoidal waveform. In the output stage, the power switching devices SW1, SW2, SW5 and SW6 form a bridge control circuit. In addition, Coil A and Coil C act as the primary winding of the transformer, and Coil D and Coil E act as the secondary winding of the transformer. The output bridge rectifier converts the AC signal on the secondary side of the transformer into DC power. Inductor L1 and output capacitor C2 are connected on the output side of the output bridge rectifier to remove pulsating components.

[00108] In this mode, the PFC boost input stage can convert single-phase AC grid power into DC power while performing power factor compensation to achieve a sinusoidal input current. Then, the bridge control circuit of the second stage can receive DC power from the first stage as an input, invert it into AC power, and pass the inverted AC power through a transformer formed by the motor windings so that complete isolation is achieved. The AC power output by the transformer is applied to the output bridge rectifier and then to the output filter to generate DC power that charges the rechargeable battery.

Fifth Embodiment

[00109] In this fifth embodiment, the charging power is supplied from a single-phase power source or a single-phase split power source, and the charging power path comprises a single-phase or split-phase push-pull PFC input stage with additional diodes.

[00110] FIG. 11A shows a schematic drawing related to an onboard propulsion system according to the fifth embodiment of the present exercise. In FIG. 11A, some of the coils used to build the charge mode transformer are connected in parallel when the system is in traction mode. Fig. 11B shows another schematic drawing related to an onboard propulsion system according to the fifth embodiment of the present exercise. In FIG. 11B, some of the coils used to build the charge mode transformer are connected in series when the system is in pull mode.

[00111] With the exception of the difference in the connection of the coils (parallel or series) in the thrust mode, the airborne charging and propulsion systems shown in FIG. 11A and 11B both contain a polyphase motor, a rechargeable battery, an inverter, diodes D1 and D2, an output rectifier, a configurator, and contactor kits. A polyphase motor may contain three or more stator winding phases. In some applications, alternatively, the motor may be a two-phase motor driven by two sets of half bridges. In the situation where the single-phase or split-phase push-pull PFC function is performed in the charge mode, the inverter may contain 6 power switching devices SW1, SW2, SW3, SW4, SW5 and SW6. Power switching devices can have different current carrying capacities. Additional diodes D1 and D2 are placed between the positive and negative poles of the input power source. The configurator contains a number of contactors K1, K2, K3, K4, K5, K6, K7, K8, K9 and K10. When properly controlled, the configurator serves to reconfigure the connections of the various components, in particular the connections between the coils A-E of the windings and/or the power switching devices SW1-6, in order to switch the system between different operating modes. A set of contactors K1 and K2 can be used to connect and disconnect the positive and negative terminals of a rechargeable battery. Contactors K1 and K2 are open in charge mode and closed in pull mode. A set of contactors K3 and K4 can be used to connect and disconnect from the incoming AC power. Contactors K3 and K4 are closed in charge mode and open in pull mode.

[00112] In addition, the systems shown in FIG. 11A and 11B may further comprise an input filter and/or an output filter that can be used to reduce noise and voltage or current ripple. Capacitor C1 can be connected to the input side of the inverter. Although the capacitor C1 is shown here as the only one, there may also be a plurality of capacitors or a module with a plurality of capacitors assembled together. The output filter may include, but is not limited to, chokes and/or capacitors. As an example, capacitor C2 and inductor L1 are shown in FIG. 11A and 11B, which serve to smooth out the ripple voltage at the output of the rectifier in order to power the battery. Although the output capacitor C2 is shown as the only one, there may also be a plurality of capacitors or a module with a plurality of capacitors assembled together. Alternatively, if the battery is adapted to accept a ripple current on the output side of the output bridge rectifier, capacitor C2 may be omitted.

[00113] Although not shown in FIG. 11A and 11B, other circuit protection components may be included in the system, including, but not limited to, pre-charge circuits, discharge circuits, inrush protection circuits, and so on.

[00114] Similar to the first to fourth embodiments, at least one of the windings wound on the motor stator teeth may have a split structure. The split windings have separate terminals that can be reconfigured into different connections to apply to charge mode and thrust mode. For example, the winding for phase A is divided into coil A and coil D, the winding for phase C is divided into coil C and coil E.

[00115] In order to configure the onboard propulsion system as illustrated in FIG. 11A, in traction mode, contactors K1, K2, K6, K7 and K8 close and K3, K4, K9 and K10 open. Accordingly, the traction power path is constructed as shown in FIG. 12A. In the operating mode shown in Fig. 12A, all windings that are seated on the same tooth are connected in parallel: coil A and coil D together form phase A, coil C and coil E together form phase C; and coil B forms phase B on its own.

[00116] Similarly, in order to configure the system as shown in FIG. 11B, in traction mode, contactors K1, K2, K6 and K8 close and K3, K4, K7, K9 and K10 open. Accordingly, the traction power path is constructed as shown in FIG. 12b. In the operating mode shown in Fig. 12B, all coils that are seated on the same tooth are connected in series: coil A and coil D together form phase A; coil C and coil E together form phase C; and coil B forms phase B on its own.

[00117] When the onboard propulsion system is in traction mode, the rechargeable battery can supply DC power to the polyphase inverter. Then, the inverter can convert the DC power into AC power and thus drive the polyphase motor.

[00118] In order to configure the onboard propulsion system as shown in FIG. 11A, in charge mode, contactors K3, K4, K9 and K10 close and K1, K2, K6, K7 and K8 open. In order to configure the onboard charge/propulsion system as shown in FIG. 11B, in charge mode, contactors K3, K4, K7, K9 and K10 close and K1, K2, K6 and K8 open. Fig. 12C shows the charging electrical path as built, which is applied to both onboard traction systems shown in FIG. 11A and 11B.

[00119] When the onboard propulsion system is configured in charge mode, a fully isolated two-stage charger is provided that includes a single-phase or split-phase push-pull PFC input stage with additional diodes and a fully isolated DC/DC output stage. In a push-pull PFC input stage, coil B can act as a step-up choke and power switches SW3 and SW4 can act as step-up PFC switches. Diode D1 conducts during the positive half-cycles of the input voltage, and the power switching device SW3 is PWM controlled so as to give the input current a sinusoidal waveform. During the negative half cycle of the input voltage, the diode D2 conducts and the power switching device SW4 is PWM controlled so as to give the input current a sinusoidal waveform. In the DC/DC output stage, the power switching devices SW1, SW2, SW5 and SW6 form a bridge control circuit. In addition, Coil A and Coil C act as the primary winding of the transformer, and Coil D and Coil E act as the secondary winding of the transformer. The output bridge rectifier converts the AC power output from the secondary side of the transformer into DC power. Inductor L1 and output capacitor C2 are connected on the output side of the output bridge rectifier to remove ripple components in the DC power.

[00120] In this charge mode, the PFC boost input stage can convert single-phase AC grid power into DC power while performing power factor compensation to achieve a sinusoidal input current. Then, the bridge control circuit of the second stage can receive the DC power of the first stage as an input, invert it into AC power, and pass the inverted AC power through a transformer formed by the motor windings so that complete isolation is achieved. The AC power output by the transformer is applied to the output bridge rectifier and then to the output filter so as to generate DC power which charges the rechargeable battery.

[00121] FIG. 13 shows a flowchart related to the operation of the onboard propulsion system according to the example of this exercise. Normally, the system operates in traction mode. In this mode, contactors K1 and K2 are closed, K3 and K4 are open, and the configurator is in the traction state, so that the battery outputs electricity to the electric motor along the traction electricity path. When it is determined that the charge request for the electric vehicle battery is received, that the vehicle is in the parking state, and that the charging cable adapted to connect the system to an external power source is inserted, the system must be switched to the charge mode. In order to carry out the switchover from the drive mode to the charge mode, the contactors K1 and K2 are opened and the electrical energy stored in the capacitors C1 and C2 is discharged. Then, the configurator switches from the thrust state to the charge state. While contactors K1 and K2 are kept open, capacitor C1 is precharged and then contactors K3 and K4 are closed. Based on a request from the vehicle's battery management system, the battery starts charging. The charge mode continues until it is determined that the battery is fully charged, or that the electrical connection to the external power source is disconnected, or that any failure is detected during the charge process. If either of these conditions is met, the battery charge is terminated and the system switches from charge mode back to thrust mode by opening contactors K3 and K4 and discharging the electrical energy stored in both capacitors C1 and C2. Then, the configurator switches from the state of charge to the state of thrust. While contactors K3 and K4 are kept open, capacitors C1 and C2 are precharged and then contactors K1 and K2 are closed. The system returns to normal thrust mode until the next charge request is received.

[00122] FIG. 14 shows a schematic drawing related to the pre-charge of the capacitor C1 according to the example of the present teaching. As discussed above, input capacitor C1 must be charged before contactors K3 and K4 close. For example, in the onboard charging and propulsion system shown in FIG. 2B, the pre-charge may be performed by a branch including an additional contactor K9 and a resistor R1. Resistor R1 is connected in series with contactor K9, serving to limit the precharge current.

[00123] In the charge mode, the charging electric power can be applied by following the sequence below. First, the contactors K1, K2, K5, K6, K7, K8, K9 and K10 switch over to the charging position. With contactors K3, K4 and K9 open, AC input power is applied. This usually involves a handshake process with an external power supply interface. Then, contactors K4 and K9 are closed to allow capacitor C1 to be pre-charged. The charging time may be at least about 5 times the time constants for R1 and C1 so that the capacitor C1 is fully charged. After the pre-charge of the capacitor C1 is completed, the contactor K3 can be closed and K9 can be opened in order to save coil power dissipation.

[00124] In the example shown in FIG. 14, the charge path exists from the input power supply, through the top diodes in the input bridge rectifier, the contactor K9, the resistor R1, the coil B, the anti-parallel diode of the power switching device SW3, to the anode side of the capacitor C1. The return path exists from the cathode side of capacitor C1, through contactor K4 and the bottom diodes of the input bridge rectifier, back to the input power supply.

[00125] The output filter capacitor C2 may also be precharged before the rechargeable battery is connected. Since the capacitor C2 is connected between the ends of the rechargeable battery, the pre-charge of the capacitor C2 can be performed through the control system of the rechargeable battery, which is not shown in FIG. 14.

[00126] Taking the first embodiment as an example, FIG. 15A shows a high-level schematic drawing related to the hardware components of an onboard propulsion system in accordance with the present teaching. In addition to the components previously described with reference to FIG. 2A, various additional components are contained in the system including, but not limited to, current sensors, voltage sensors, temperature sensors (not illustrated in FIG. 15A), a resolver, or any other sensor (not illustrated in FIG. 15A) adapted to providing the necessary degree of identification of the angular position of the motor rotor, and the central charge / thrust control device, etc.

[00127] As shown in FIG. 15A, isolated voltage detection is provided to measure DC link bus voltage and battery voltage, respectively. The detected voltage signals are transmitted to the charge/traction control device. In drive mode, the DC link bus voltage and the battery voltage become the same signal. They are separate signals in charge mode. The voltage detection function can be performed by means of isolated sensors available on the market, such as integrated circuit sensors. This type of isolated sensor requires isolated power and sharing resistors on the high voltage side. In a situation where complete galvanic isolation is not needed, detection approaches based on high impedance differential amplifiers are also possible.

[00128] Isolated current detection is also shown in FIG. 15A. More specifically, an isolated current sensor is provided for detecting current in a half-bridge containing power switching devices SW1 and SW2 (corresponding to phase A). Similarly, there are current sensors for the other two half-bridges, one is used for the half-bridge consisting of power switching devices SW3 and SW4, the other for the half-bridge consisting of power switching devices SW5 and SW6. The current sensors can be implemented by Hall current sensors. Alternatively, shunts with decoupling amplifiers can be used. In order to save costs, two current sensors can meet the control requirements for the motor and charging system. However, in order to obtain improved protection, three or more current sensors may be used. For example, if less accuracy is acceptable, the charging current can be estimated from the primary current detected by the phase A and phase C sensors. current is provided to measure the charging current. Similar to the three-phase current sensors, the fourth current sensor can be a Hall current sensor, a shunt, etc.

[00129] The charge/traction control device receives signals from various sensors as input and generates commands to control power switching devices and contactors. The controller may be a DSP, FPGA, MCU or any other suitable programmable controller. Isolating gate drivers are connected between the charge/pull control device and the power switching devices to connect drive signals between isolation boundaries and provide high ripple currents to allow the power switching devices to turn on/off quickly for lower losses. Various insulated gate drivers available on the market may be used, including, but not limited to, optical coupled drivers, capacitive coupled drivers, and the like.

[00130] Taking the third embodiment as an example, FIG. 15B shows a high-level schematic drawing relating to the hardware components of an onboard propulsion system according to another example. In addition to the components previously described with reference to FIG. 7A, various additional components are contained in the system including, but not limited to, current sensors Ia, Ib1, Ib2, Ib3, Ic, and Iout, voltage sensors VI1, VI2, VI3, Vdc, and Vout, temperature sensors (not illustrated in FIG. 15B), a central charge/thrust controller and a resolver or any rotor position sensor (not illustrated in fig. 15B) to sense rotor position, etc.

[00131] FIG. 16 shows more details of the connection from a charge/traction control device to an insulated gate excitation control device that has enhanced PWM output signals (EPWM) to drive power switching devices SW1-SW6 included in an onboard charge/traction system according to with the first embodiment of this teaching. Driven by the EPWM1A and EPWM1B signals, the power switching devices SW1 and SW2 form phase A excitation in pull mode and operate as part of the PWM excitation of the transformer in charge mode. Driven by the signals EPWM3A and EPWM3B, the power switching devices SW5 and SW6 form phase C excitation in pull mode and operate as part of the PWM excitation of the transformer in charge mode. Driven by signals EPWM2A and EPWM2B, the power switching devices SW3 and SW4 form B-phase excitation in pull mode and act as a boost converter in charge mode. Separate enabling outputs are provided for phases A and C and for phase B. The reason is that they play different roles in charge mode. The processor pin assignments may vary depending on the type of processor used, but are not limited to the assignments illustrated in FIG. 16.

[00132] In the example shown in FIG. 16, the power switching devices SW1 to SW6 are turned on by the respective PWM outputs at a low level, turned off by the respective PWM outputs at a high level. As such, inverters are placed at the outputs and pull-up resistors are provided to ensure that the power switching devices turn off while the processor is reset. If the control logic is designed such that the high-level PWM output turns on the appropriate power switching device, then inverters are not needed, and logic-down resistors are provided instead of the logic-boost resistors shown in FIG. 16.

[00133] As an example of the fail-safe functions applied to the on-board propulsion system of this exercise, FIG. 16 shows a failure detection and latching module that is separate from the processor. This approach saves more hardware resources, but provides better protection, especially when the processor locks up, when there are code problems (which usually occur during the development period), etc.

[00134] FIG. 17 shows an exemplary control scheme performed in charge mode of an onboard charge/propulsion system in accordance with this exercise. The charge control circuit as shown may be implemented with an onboard DSP or discrete control electronics. The battery can be charged either in constant current mode or in constant voltage mode. Typically, in order to ensure the alignment of the cells in a rechargeable battery, the charge is carried out in the constant current mode at the beginning of the charging process, and then changes to the constant voltage mode. Compared to the situation of constant current mode, lower charging electric power is used in constant voltage mode.

[00135] As can be seen in FIG. 17, the voltage control loop included in the charge/draft control device has a plurality of voltage limit inputs. Typically, the control system of the rechargeable battery may provide the voltage control loop with information associated with the maximum voltage that the rechargeable battery can currently accommodate. Such a battery voltage limit may be sent from the battery management system to the charge/traction control device via any suitable data link, such as a CAN data bus. Also introduced into the voltage control loop is a hardware voltage limit, which represents how high the voltage that the charging electrical path can safely generate. The hardware voltage limit is not the maximum voltage that the charging electricity path is designed to produce, but a maximum voltage limit determined based on component load limits. Optionally, via the debug data link, for example, the debug voltage limit is also reported to the voltage control loop. The debug voltage limit is useful in debugging and developing an onboard propulsion system.

[00136] Based on the battery voltage limit, the hardware voltage limit, and optionally the debug voltage limit when entered, the MIN 1 block generates and outputs a voltage command to summing node 1. The generated voltage command represents the minimum of the various voltage limits entered. In the summing node 1, the voltage command is compared with the detected actual voltage so as to obtain a voltage error. This voltage error is input to the PI controller 1 to generate the current command. Alternatively, various controllers, including but not limited to integral controllers, can be used in place of the PI controller 1. The generated current command is sent as an input to the current control loop MIN 2 of the charge/draft controller.

[00137] As can be seen in FIG. 17, in addition to the current command output from the voltage control loop PI controller 1, the current control loop block MIN 2 included in the charge/draft control device receives a plurality of current limits as input. Similarly, the control system of the rechargeable battery may provide the current control loop with information associated with the maximum current that the rechargeable battery can currently accommodate. Such a battery current limit can be sent from the battery management system to the charge/traction control device via a CAN data bus, for example. Also, a hardware current limit is introduced into the current control loop. In one aspect, the hardware current limit reflects the current carrying capacity of the charging electricity path. For example, the charging electrical path may have a limited current carrying capacity of about 200 A. In another aspect, hardware current limiting reflects limited input electrical power due to the maximum input current that can be drawn from the input line. This maximum input current can be calculated based on the battery voltage. Alternatively, an input current sensor can be used to provide more accurate input current information. More accurate information about the current is available, closer to the input current limit, the onboard charging and traction system is given the opportunity to work. Again, the optional debug current limit is signaled to the current control loop via the debug data link.

[00138] Based on the current command from the current control loop PI controller 1 of the hardware current limit, battery current limit, and optional debug current limit, when entered, the MIN block 2 generates and outputs a current command to summing node 2. The generated current command represents the minimum of various inputs. Since the current command from the voltage control loop is used as an input command to the current control loop, the charge/draft control device is able to limit the voltage on the rechargeable battery. If the current command from the voltage control loop is below the other current limits entered in the MIN 2 block, that is what is controlling and thus the charger is operating in voltage control mode. If any of the current limits entered in the MIN 2 block is below the current command from the voltage control loop, then the charger operates in current control mode with the lowest current limit being the given current command. In the summing node 2, the commanded current setpoint is compared with the detected actual current so as to obtain a current error. This current error is input to the PI controller 2 to generate the phase shift command. Alternatively, various controllers, including but not limited to integrated controllers, can be used instead of PI controller 2. The output of PI controller 2 is a phase shift command that is used to change the phase shift between PWM signals EPWM3 and EPWM1. The phase shift command must be limited to be kept within the required range to prevent gain reversal. For example, the range is from 1 to 180 degrees.

[00139] The vehicle typically operates in a traction mode. When the charge/thrust control device switches from the charge state to the thrust state, the pattern of EPWM output signals from the processor of the charge/thrust control device switches accordingly. In the pull state, the processor is configured to produce a three-phase PWM output, with dead time between the top power switching devices and the bottom power switching devices in each leg of the inverter bridge to avoid flashover. Since the present teaching does not change the way the electric motor is driven in the traction mode, conventional technologies are applicable for traction control. For example, traction control may be implemented by means of a standard Profile Control (FOC) device, with a sensor providing a feedback signal associated with the shaft position to the motor rotor output shaft. Typically, a resolver is attached to the motor to measure the position of the shaft.

[00140] Although only one motor, one rechargeable battery, one inverter, one input bridge rectifier, and one output bridge rectifier are illustrated in the drawings accompanying the description of the first to fifth embodiments, one skilled in the art may expect that a plurality of electric motors, rechargeable batteries, inverters, input bridge rectifiers and/or output bridge rectifiers can be provided in the onboard traction and charge system. For example, two motors may drive the front and rear wheels in an electric vehicle separately, or similarly, four motors may drive each wheel separately. In the following, two approaches for practicing the present teaching with multiple motors will be discussed with reference to FIG. 18A-20B.

[00141] FIG. 18A-18G show schematic drawings relating to various connections of more than one electric motor and/or more than one battery of an onboard propulsion system in accordance with examples of this exercise. One electric motor and its accompanying inverter charger system or a plurality of electric motors and their accompanying inverter charger systems may be connected to the same battery or to different batteries. The combination of the inverter-charger system and the electric motor each work independently to charge the battery or batteries. The battery may be separate without an electrical connection between them. Alternatively, at least some of the batteries may be connected in series or in parallel.

[00142] FIG. 19 shows a schematic drawing relating to connections of two or more inverter chargers and a battery according to another exemplary example. In this scenario, two or more inverter chargers can be used as different stages of the charging electricity path in charge mode. More specifically, one or more inverter chargers of the plurality of inverter chargers in the system may operate as the first stage, while the other one or more inverter chargers of the plurality of inverter chargers may operate as the second DC/ DC cascade. The first stage may be a PFC boost or front stage with a single or multiple phase boost converter. The second stage can be connected in parallel or in series. In traction mode, two or more inverter chargers can work independently or together.

[00143] In order to configure the system shown in FIG. 19, in pull mode, contactors K1, K2, K6, K7, K8, K13, K17 and K20 close while K3, K4, K5, K9, K10, K14, K15, K16, K18, K19 and K21 open . As a result, a traction power path is formed as shown in the simplified circuit diagram of FIG. 20A. In FIG. 20A, the same rechargeable battery is connected to drive both electric motors.

[00144] In order to configure the system shown in FIG. 19, in charging mode, contactors K1, K2, K6, K7, K8, K13, K17 and K20 open while K3, K4, K5, K9, K10, K14, K15, K16, K18, K19 and K21 close . As a result, a charging electric path is formed as shown in the simplified circuit diagram in FIG. 20b. When the system is configured in charge mode, a fully isolated two-stage charger is provided that contains a full three-phase PFC boost input stage and a fully isolated DC/DC output stage. In the input stage, coil A, coil B, and coil C act as step-up chokes, and power switching devices SW1, SW2, SW3, SW4, SW5, and SW6 in inverter 1 act as step-up PFC switches. In the DC/DC output stage, the power switching devices SW1, SW2, SW3, SW4, SW5 and SW6 in inverter 2 constitute a three-phase drive bridge circuit, the windings of coil A1, coil B1 and coil C1 act as the primary winding of the transformer, and coil A2 , coil B2 and coil C2 as the secondary winding of the transformer.

[00145] In PFC charge mode, the step-up front end can convert the multi-phase mains voltage to DC voltage while performing power factor compensation with respect to the mains. Then, the bridge driving circuit in the output stage can receive DC power from the first stage as an input, invert it into AC power, and pass the inverted AC power through a transformer formed by the motor windings so that complete isolation is achieved. AC power output from the transformer is applied to an output bridge rectifier and then an output filter so as to generate DC power to charge a rechargeable battery.

[00146] While the present teaching is primarily described in the context of electric vehicles, the concepts and inventive ideas disclosed herein are applicable to any electronic device that contains one or more electric motors and one or more storage devices. electrical energy (such as rechargeable batteries). Examples of such an electrical device include, but are not limited to, plug-in electric hybrid vehicles, electric boats, electric aircraft, electric trains, electric motorcycles, electric bicycles, electric skateboards, electric tools, electric drones, electric submarines, and electric cars, such as: electric bulldozers, electric tractors, electric forklifts, electric excavators, etc. The concepts and ideas of the invention may also find application in electrical equipment for special purposes such as explosion-proof electric vehicle, explosion-proof electric tools, explosion-proof tracked vehicle, etc.

[00147] It will be apparent to those skilled in the art that the configurator that is used to reconfigure the connections between thrust mode and charge mode may consist of mechanical switches, electromagnetic contactors, solid state switches, or any type of switching mechanism that can disconnect or connect electrical connections.

[00148] Those skilled in the art will appreciate that the inverter may be any multi-phase inverter. The power switching devices in the inverter can be silicon IGBT power modules, MOSFETs, or any other power switching device suitable for switching the intended power levels. Power switching devices can be based on silicon, GaN, SiC or any other technology.

[00149] It will be apparent to those skilled in the art that the motor used to implement this teaching can be any type of motor that consists of at least two winding phases, including but not limited to, asynchronous induction motor, PMSM motor , BLDC motor, BLAC motor, synchronous reluctance motor.

[00150] Since the present teaching takes advantage of the components that pre-exist in the inverter(s) and motor(s) of the electric vehicle, the maximum charging electric power is limited. Those skilled in the art will appreciate that motor(s) and inverter(s) having higher power ratings can be used to increase the upper limit of charging electricity. In addition, upon request from the vehicle, the charging system is capable of charging the battery at a lower capacity than the maximum charge level.

[00151] With the design disclosed herein, windings in the motor(s) and power switching devices in the inverter(s) can be used to form a two-stage step-up and step-down fully isolated switching power supply.

[00152] With the design disclosed herein, two or more sets of windings may be provided on at least one stator tooth. At least one stator tooth can act as the core of a transformer to transfer electrical power from the primary winding to the secondary winding without rotating the motor rotor.

[00153] With the design disclosed herein, one or more motor stator windings, one end of which is initially connected to the motor star point, is capable of being disconnected from the motor star point through a set of contactors and forming the components of a two stage fully isolated switching power supply.

[00154] With the design disclosed herein, by means of a set of contactors, the initially electrically connected winding in pull mode can be used to form two sets of fully isolated windings in charge mode.

[00155] While the foregoing has described what is considered to constitute the present teachings and/or other examples, it is understood that various modifications may be made to it, and that the subject matter disclosed herein may be implemented in various forms and examples, and that the teachings can be applied to numerous applications, only a few of which have been described in this document. It is intended by the following claims to state any and all uses, modifications, and variations that fall within the true scope of the present teaching.

Claims (63)

1. Reconfigurable traction-charging system located in an electrical device with a rechargeable battery, containing: an electric motor comprising a stator having a plurality of stator teeth and a plurality of stator windings wound on a plurality of stator teeth, wherein the stator winding on at least one stator tooth of the electric motor is divided into two or more coils; an inverter containing a plurality of power switching devices; output rectifier; a configurator comprising a plurality of contactors connected to a plurality of stator windings and a plurality of power switching devices; And a controller for controlling the plurality of power switching devices and the plurality of contactors so as to configure the system to operate in one of a drive mode and a charge mode; wherein in traction mode: a rechargeable battery supplies electrical energy to the electric motor through an inverter; And two or more coils are connected in series; And in charge mode: connections associated with a plurality of power switching devices and stator windings are configured by a configurator to form a charger that consumes electrical power from an external power source to charge a rechargeable battery; And two or more coils are connected in parallel. 2. Reconfigurable traction-charging system according to claim 1, while the external power supply is a multi-phase power supply; the system additionally contains an input bridge rectifier; And an input bridge rectifier, a charger, and an output rectifier form a charging power path having two stages, including a first stage being an input stage with a boost converter bridge rectifier, and a second stage being an isolated DC/DC output stage. 3. The reconfigurable traction-charging system of claim 2, wherein at least one stator winding on one or more motor stator teeth constitutes at least one step-up choke of the step-up converter. 4. Reconfigurable traction-charging system according to claim 1, while the external power supply is a single phase or split single phase power supply; the system additionally contains an input bridge rectifier; And the input bridge rectifier, the charger, and the output rectifier form a charging power path having two stages, including a first stage being an input stage with a PFC bridge rectifier with a boost converter, and a second stage being an isolated DC/DC output stage. 5. The reconfigurable traction-charging system of claim 4, wherein at least one stator winding on one or more motor stator teeth constitutes at least one boost choke of the boost converter. 6. Reconfigurable traction-charging system according to claim 1, while the external power supply is a multi-phase power supply; And the charger and the output rectifier form a charge path having two stages including a first stage being a multi-phase PFC boost input stage and a second stage being an isolated DC/DC output stage. 7. Reconfigurable traction-charging system according to claim 1, while the external power supply is a single-phase or split-phase power supply; And the charger and the output rectifier form a charge path having two stages including a first stage being a single-phase PFC boost input stage and a second stage being an isolated DC/DC output stage. 8. Reconfigurable traction-charging system according to claim 1, while the external power supply is a single-phase or split-phase power supply; And the system further comprises two diodes, wherein the two diodes, the charger, and the output rectifier form a charge path having two stages, including a first stage being a single-phase push-pull PFC boost input stage and a second stage being an isolated DC/DC output stage . 9. A method for implementing a reconfigurable traction-charging system located in an electrical device having a rechargeable battery, said method comprising the steps of: configuring, by means of a configurator under the control of the controller, the system to operate in the thrust mode; upon receiving a charge request for a rechargeable battery, configuring the system to operate in charge mode by means of a configurator; And when determining that the criterion associated with the rechargeable battery is satisfied, the system is configured by means of the configurator to operate in thrust mode, wherein the system comprises a controller, a configurator, an electric motor, an inverter and an output rectifier, the electric motor comprises a stator having a plurality of stator teeth and a plurality of stator windings wound on a plurality of stator teeth, while the stator winding on at least one stator tooth of the electric motor is divided into two or more coils, the inverter contains a plurality of power switching devices, the configurator contains a plurality of contactors connected to a plurality of stator windings and a plurality of power switching devices; wherein in traction mode: a rechargeable battery supplies electrical energy to the electric motor through an inverter; And two or more coils are connected in series; And in charge mode: connections associated with a plurality of power switching devices and stator windings are configured by a configurator to form a charger that consumes electrical power from an external power source to charge a rechargeable battery; And two or more coils are connected in parallel. 10. A method for implementing a reconfigurable traction-charging system according to claim 9, while the external power supply is a multi-phase power supply; the system additionally contains an input bridge rectifier; And an input bridge rectifier, a charger, and an output rectifier form a charging power path having two stages, including a first stage being an input stage with a boost converter bridge rectifier, and a second stage being an isolated DC/DC output stage. 11. A method for implementing a reconfigurable traction-charging system according to claim 10, wherein at least one stator winding on one or more stator teeth of the electric motor constitutes at least one step-up choke of the step-up converter. 12. A method for implementing a reconfigurable traction-charging system according to claim 9, while the external power supply is a single phase or split single phase power supply; the system additionally contains an input bridge rectifier; And the input bridge rectifier, the charger and the output rectifier form a charge path having two stages including a first stage being an input stage with a PFC bridge rectifier with a boost converter and a second stage being an isolated DC/DC output stage. 13. A method for implementing a reconfigurable traction-charging system according to claim 12, wherein at least one stator winding on one or more stator teeth of the electric motor constitutes at least one step-up choke of the step-up converter. 14. A method for implementing a reconfigurable traction-charging system according to claim 9, while the external power supply is a multi-phase power supply; And the charger and the output rectifier form a charge path having two stages including a first stage being a multi-phase PFC boost input stage and a second stage being an isolated DC/DC output stage. 15. A method for implementing a reconfigurable traction-charging system according to claim 9, while the external power supply is a single-phase or split-phase power supply; And the charger and the output rectifier form a charge path having two stages including a first stage being a single-phase PFC boost input stage and a second stage being an isolated DC/DC output stage. 16. A method for implementing a reconfigurable traction-charging system according to claim 9, while the external power supply is a single-phase or split-phase power supply; And the system further comprises two diodes, wherein the two diodes, the charger, and the output rectifier form a charge path having two stages, including a first stage being a single-phase push-pull PFC boost input stage and a second stage being an isolated DC/DC output stage .

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