Asymmetric phase current-based charging controller

Abstract

The present invention relates to an asymmetric phase current-based charging controller. The present invention comprises: a charging method selector for selecting a charging method using one of an asymmetric two-phase current or an asymmetric three-phase current; a first position controller for generating a torque command when the charging method using the asymmetric two-phase current is selected; a two-phase current reference generator for generating a stator phase current command when the charging method using the asymmetric two-phase current is selected; a second position controller for generating a torque command when the charging method using the asymmetric three-phase current is selected; a three-phase current reference generator for generating a stator phase current command when the charging method using the asymmetric three-phase current is selected; and a current controller for controlling the stator phase current of a motor to follow the stator phase current command generated by the two-phase current reference generator or the three-phase current reference generator.

Description

Asymmetric phase current-based charge controller

[0001] The present invention relates to a charging controller that utilizes asymmetric phase current in an integrated charger that utilizes a motor-inverter system equipped in an electric vehicle to charge the battery of the electric vehicle.

[0002] Recently, the voltage of electric vehicle batteries has increased to 800V, which is double the previous level.

[0003] While increasing battery voltage offers advantages such as improved energy efficiency, faster charging speeds, and reduced cable size, a corresponding charging system is required.

[0004] Meanwhile, since many of the chargers currently in widespread use are still designed to be suitable for 400V systems, research is needed on a method to charge 800V system electric vehicles using a 400V charging system.

[0005] Among electric vehicle battery charging methods, one technology that charges a high-voltage battery using a low-voltage charger involves adding an on-board converter. While this method has the advantage of relatively high charging efficiency, it has the disadvantage of reduced energy efficiency due to increased costs and weight.

[0006] Another technology for charging high-voltage batteries with a low-voltage charger is the integrated charger, which utilizes the electric vehicle's motor drive system for charging. Integrated chargers offer the advantages of reduced manufacturing costs and increased energy efficiency, but they have the disadvantages of low charging efficiency and long charging times.

[0007] FIG. 1 is a drawing of an electric vehicle charging system with a conventional integrated charger, and FIG. 2 is a drawing showing a charging method with a conventional three-phase interleaved switching.

[0008] Referring to Figures 1 and 2, the integrated charger can be controlled like three pairs of boost converters by controlling the current of each phase through inverter switching, where the stator winding of the motor acts as the inductor of the boost converter.

[0009] Meanwhile, conventional technology for charging high-voltage batteries with a low-voltage charger using an integrated charger controls the average value of each phase current equally, which results in the following various problems.

[0010] When charging using an integrated charger, a magnetic field is generated by the phase current, and torque may occur during charging due to the magnetic flux of the generated magnetic field, which poses a problem as it can lead to safety issues.

[0011] Therefore, when charging using an integrated charger, torque must be prevented from occurring, and conventional technology utilizes all windings for charging and controls the DC value of each phase current equally to prevent rotor rotation.

[0012] Specifically, the prior art is a torque (T) generated by d-axis current and q-axis current. dq = 1.5pp(Ψ f +(L d -L q )i r ds )i r qs It makes ) 0, but in fact, the zero-sequence current (i) during charging ns Since ) has a non-zero value, zero-sequence torque (T n = 3pp(∂Ψ n / ∂θ r )i ns ) has a non-zero value.

[0013] Considering these video-part torques, when applying conventional technology, the total torque (T e =T dq +T nThere is a problem that ) is not zero, which can damage the system. In actual applications, the torque due to the charging current has a non-zero value, but rotation is suppressed by the parking brake, parking gear, friction between the tire and the ground, etc.

[0014] An electric vehicle charging system with a conventional integrated charger as exemplified in Fig. 1 has a structure in which a low-voltage charger is connected between the neutral point of the motor and the negative electrode of the battery.

[0015] According to this, the stator winding acts as the inductor of the boost converter and performs current control of the boost converter through inverter switching. This structure is identical to a three-phase interleaved boost converter.

[0016] As illustrated in FIG. 2, which shows a charging method applying conventional three-phase interleaved switching, the conventional technology uses each phase current (i as , i bs , i cs It is a method of reducing torque generated by d-output current and q-axis current by equally controlling the DC component of ).

[0017] Conventional technology primarily uses a method that reduces the pulsation component of the phase current compared to the phase switching method by utilizing three-phase interleaved switching.

[0018] However, when performing DC-DC power conversion with a step-up ratio of 2 required by the industry, even if three-phase interleaved switching is applied, there is a problem in that the magnitude of losses in the motor is large due to significant phase current ripple caused by zero-sequence voltage. This is because the magnitude of the zero-sequence inductance of an integrated charger is generally very small compared to the differential mode inductance.

[0019] In addition, conventional current control methods have the problem of not considering zero-sequence torque generated by n-axis current and not including rotation suppression control.

[0020] [Prior Art Literature]

[0021] [Patent Literature]

[0022] Korean Published Patent Application No. 10-2016-0038348 (Publication Date: April 07, 2016, Title: Charging Device with Integrated Low-Voltage DC-DC Converter)

[0023] Korean Published Patent Application No. 10-2025-0006734 (Publication Date: January 13, 2025, Title: Integrated Charger)

[0024] The technical objective of the present invention is to provide an asymmetric phase current-based charging controller capable of improving charging efficiency and suppressing torque caused by charging current by controlling the charging process using asymmetric phase current in an integrated charger that utilizes a motor-inverter system to charge a high-voltage battery with a low-voltage charger.

[0025] The present invention, for solving such technical problems, is a charging controller utilizing asymmetric phase current in an integrated charger utilizing a motor-inverter system equipped in an electric vehicle to charge the battery of the electric vehicle, comprising: a charging method selector that selects a charging method using one of asymmetric two-phase current and asymmetric three-phase current according to state information of the motor-inverter system; and when the charging method using the asymmetric two-phase current is selected by the charging method selector, the rotor position command (θ) of the motor r * ) and rotor position (θ r Torque command (T) to reduce the difference of ) e * A first position controller that generates ), and when a charging method using the asymmetric two-phase current is selected by the charging method selector, a stator phase current command (i) for synthesizing a torque command received from the first position controller. * abcsA two-phase current reference generator that generates ), a second position controller that generates a torque command to reduce the difference between the rotor position command and the rotor position of the motor when the charging method using the asymmetric three-phase current is selected by the charging method selector, a three-phase current reference generator that generates a stator phase current command to synthesize the torque command received from the second position controller when the charging method using the asymmetric three-phase current is selected by the charging method selector, and the stator phase current (i) of the motor abcs It includes a current controller that controls the stator phase current command generated by the two-phase current reference generator or the stator phase current command generated by the three-phase current reference generator to follow.

[0026] In an asymmetric phase current-based charging controller according to the present invention, the state information is a battery voltage (V bat ) and charger voltage (V ch The voltage step-up ratio (V) which is the ratio of ) bat / V ch ), charger current(i ch It is characterized by including one or more of the size of ) and the rotor position of the motor.

[0027] In an asymmetric phase current-based charging controller according to the present invention,

[0028] The above two-phase current reference generator is the angle (θ) of the stator current command calculated by the torque command generated by the first position controller. i * =atan(i * βs / i * αs )) and charger current command (i * chThe above-mentioned stator phase current command is generated according to the above-mentioned method, and the three-phase current reference generator is characterized by generating the above-mentioned stator phase current command according to the angle of the stator current command calculated by the torque command generated by the second position controller and the above-mentioned charger current command.

[0029] In an asymmetric phase current-based charging controller according to the present invention, the current controller is characterized by applying a two-phase switching signal having the same DC value to an inverter constituting the motor-inverter system.

[0030] In an asymmetric phase current-based charging controller according to the present invention, the current controller is characterized by applying a three-phase switching signal having a non-identical DC value to an inverter constituting the motor-inverter system.

[0031] In an asymmetric phase current-based charging controller according to the present invention, the current controller satisfies the 0-torque condition expressed by the following Equation 1, wherein the stator dq-axis current (i) of the motor dqs It is characterized by controlling ).

[0032] [Mathematical Formula 1]

[0033]

[0034] T e is the total torque, pp is the number of pole pairs, and Ψ f is the magnetic flux linkage of the motor, and Ψ n L is the stator n-axis flux linkage, Ld is the stator d-axis inductance, Lq is the stator q-axis inductance, and θ r is the rotor position, i ds is the stator d-axis current, and i qs is the stator q-axis current, and i ns is the stator n-axis current.

[0035] In an asymmetric phase current-based charging controller according to the present invention, the current controller comprises a stator n-axis current (i ns ) to -i * ch It is characterized by controlling to / 3 and controlling the stator d-axis current and the stator q-axis current along a 0-torque hyperbola that satisfies the 0-torque condition, thereby suppressing the rotor rotation of the motor during charging.

[0036] In an asymmetric phase current-based charging controller according to the present invention, the current controller, when a charging method using the asymmetric two-phase current is selected, has a rotor position (θ) of the motor. r It is characterized by controlling ) to have a preset value.

[0037] According to the present invention, an asymmetric phase current-based charging controller is provided that can improve charging efficiency and suppress torque caused by charging current by controlling the charging process using an asymmetric phase current in an integrated charger utilizing a motor-inverter system to charge a high-voltage battery with a low-voltage charger.

[0038] FIG. 1 is a drawing of an electric vehicle charging system with a conventional integrated charger, and

[0039] FIG. 2 is a diagram showing a charging method applying conventional three-phase interleaved switching, and

[0040] FIG. 3 is a diagram showing an electric vehicle charging system to which an asymmetric phase current-based charging controller according to an embodiment of the invention is applied, and

[0041] FIG. 4 is a diagram showing an asymmetric phase current-based charging controller according to an embodiment of the invention, and

[0042] FIG. 5 is a diagram illustrating a charging method using asymmetric two-phase current in one embodiment of the present invention, and

[0043] FIG. 6 is a diagram illustrating a charging method using asymmetric three-phase current in one embodiment of the present invention, and

[0044] FIG. 7 is a diagram showing the torque sign on the dq plane when ∂Ψn / ∂θr < 0 in one embodiment of the present invention, and

[0045] FIG. 8 is a diagram showing the torque sign on the dq plane when ∂Ψn / ∂θr > 0 in one embodiment of the present invention, and

[0046] FIG. 9 is a diagram showing the efficiency measurement results according to the charging boost ratio in one embodiment of the present invention, and

[0047] FIG. 10 is a diagram showing a comparison of efficiency measurement results between a three-phase charging method and a two-phase charging method according to charging power in one embodiment of the present invention, and

[0048] FIG. 11 is a diagram showing a comparison of efficiency measurement results between a three-phase charging method and a two-phase charging method according to the motor rotor position in one embodiment of the present invention.

[0049] Specific structural or functional descriptions of embodiments according to the concept of the present invention disclosed herein are provided merely for the purpose of explaining embodiments according to the concept of the present invention, and embodiments according to the concept of the present invention may be implemented in various forms and are not limited to the embodiments described herein.

[0050] Embodiments according to the concept of the present invention may be subject to various modifications and may take various forms; therefore, embodiments are illustrated in the drawings and described in detail in this specification. However, this is not intended to limit the embodiments according to the concept of the present invention to specific disclosed forms, and includes all modifications, equivalents, or substitutions that fall within the spirit and scope of the present invention.

[0051] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as generally understood by those skilled in the art to which the present invention pertains. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and should not be interpreted in an ideal or overly formal sense unless explicitly defined herein.

[0052] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings.

[0053] FIG. 3 is a drawing showing an electric vehicle charging system to which an asymmetric phase current-based charging controller (10) according to one embodiment of the invention is applied, and FIG. 4 is a drawing showing an asymmetric phase current-based charging controller (10) according to one embodiment of the invention.

[0054] Referring to FIGS. 3 and 4, an asymmetric phase current-based charging controller (10) utilizing an asymmetric phase current in an integrated charger utilizing a motor-inverter system provided in an electric vehicle to charge a battery of an electric vehicle according to one embodiment of the present invention may be configured to include a charging method selector (100), a first position controller (200), a two-phase current reference generator (300), a second position controller (400), a three-phase current reference generator (500), and a current controller (600).

[0055] Before describing an embodiment of the invention, an integrated charger is described. In the example of FIG. 3, the integrated charger includes a charger (1), an inverter (2), and a motor (3).

[0056] The integrated charger utilizes the existing motor (3) and inverter (2) equipped in the electric vehicle to charge the battery without adding a separate charging circuit.

[0057] The motor (3) of the electric vehicle can be used not only to move the vehicle but also as a generator. As the motor (3) rotates, it generates energy, and the integrated charger utilizes this energy to charge the battery. Additionally, the inverter (2) is a device that controls the rotational speed and direction of the motor (3), and the integrated charger precisely controls the inverter (2) to operate the motor (3) like a generator and converts the generated power into a form suitable for the battery.

[0058] According to this integrated charger, a separate charging circuit is not required, which can reduce the number of parts and weight of the vehicle, and the charging-related parts are integrated with the motor (3) and inverter (2), which can increase the utilization of the vehicle's interior space, and the vehicle manufacturing cost can be reduced through the reduction of the number of parts and efficient system configuration, and energy efficiency can be increased by jointly utilizing the motor (3) and inverter (2).

[0059] The operation method of the integrated charger can be explained as follows.

[0060] For example, when a vehicle is connected to a charging station, the inverter (2) operates the motor (3) like a generator to initiate a charging mode, the alternating current power generated by the motor (3) is converted into direct current power through the inverter (2), and the converted direct current power is transferred to the battery to perform charging.

[0061] The components of one embodiment of the invention will be described in detail below.

[0062] The charging method selector (100) is a component that selects a charging method using one of asymmetric two-phase current and asymmetric three-phase current according to the state information of a motor-inverter system including a motor (3) and an inverter (2) equipped in an electric vehicle.

[0063] For example, the state information used by the charging method selector (100) to select a charging method is the battery voltage (V bat ) and charger voltage (V chThe voltage step-up ratio (V) which is the ratio of ) bat / V ch ), charger current(i ch It may include one or more of the size of ) and the rotor position of the motor (3).

[0064] The configuration regarding the selection of the charging method is explained in detail and with examples as follows.

[0065] For example, voltage boost ratio (V bat / V ch The closer ) is to 2, the relatively higher the efficiency of the two-phase charging method, and the voltage boost ratio (V bat / V ch The closer ) is to 1.5 or 3, the relatively higher the efficiency of the three-phase charging method. Therefore, the charging method selector (100) has a voltage boost ratio (V bat / V ch If ) is close to 2, select the 2-phase charging method, and the voltage boost ratio (V bat / V ch If ) is close to 1.5 or 3, a three-phase charging method can be selected. Also, for example, the battery voltage changes depending on the battery charge state, so the voltage boost ratio changes. Therefore, the charging method selector (100) may be configured to switch the charging method by selecting a charging method with relatively higher charging efficiency even during charging.

[0066] For example, charger current (i ch As the size of ) increases, energy loss increases, and the increase in loss in the 2-phase charging method is relatively larger than in the 3-phase charging method. Therefore, the charging method selector (100) is the charger current (i ch If the size of ) is greater than a preset comparison standard, a three-phase charging method can be selected. In addition, the charging method with higher efficiency may change depending, for example, the current size that the battery can accept during charging.

[0067] For example, since the efficiency of the two-phase charging method and the three-phase charging method changes depending on the rotor position of the motor (3), the charging method selector (100) can select the two-phase charging method or the three-phase charging method depending on the rotor position of the motor (3).

[0068] In this way, the charging method selector (100) can increase efficiency by selecting a charging method with higher efficiency according to the battery condition, motor condition, etc. during charging, and can select an optimal charging method based on efficiency-related data measured in advance to a charging method with higher efficiency according to the system condition.

[0069] FIG. 9 is a diagram showing the efficiency measurement results according to the charging boost ratio in one embodiment of the present invention.

[0070] Referring further to FIG. 9, the results of comparing the losses of the 2-phase charging method and the 3-phase charging method when charging with varying voltage step-up ratios for any fixed rotor angle and charging current command are illustrated.

[0071] As illustrated in Fig. 9, it can be seen that the closer the voltage boost ratio is to 2, the lower the loss of the two-phase charging method compared to the three-phase charging method. Additionally, when the voltage boost ratio is 1.5, it can be seen that the loss of the three-phase charging method compared to the two-phase charging method is lower.

[0072] FIG. 10 is a diagram showing a comparison of efficiency measurement results between a three-phase charging method and a two-phase charging method according to charging power in one embodiment of the present invention.

[0073] Referring further to FIG. 10, the results of comparing the efficiency of a two-phase charging method and a three-phase charging method when charging with varying charging power for any fixed rotor angle and charger voltage are illustrated.

[0074] As a result of the measurement, it was observed that the efficiency of the two-phase charging method was relatively higher across the entire range, but the difference in efficiency between the two-phase and three-phase charging methods decreased as the charging current increased. This is because the increase in conduction loss due to the increase in current is greater in the two-phase charging method, and it can be confirmed that depending on the system, the efficiency of the three-phase charging method may become higher as the charging current increases.

[0075] When a charging method using asymmetric two-phase current is selected by the charging method selector (100), the first position controller (200) [uses] a rotor position command (θ) of the motor (3). r * ) and rotor position (θ r Torque command (T) to reduce the difference of ) e * It is a component that generates ) and outputs it to a two-phase current reference generator (300).

[0076] When a charging method using asymmetric two-phase current is selected by the charging method selector (100), the two-phase current reference generator (300) provides a stator phase current command (i) for synthesizing the torque command received from the first position controller (200). * abcs It is a component that generates ).

[0077] For example, the two-phase current reference generator (300) has an angle (θ) of the stator current command calculated by the torque command generated by the first position controller (200). i * =atan(i * βs / i * αs )) and charger current command (i * ch Stator phase current commands can be generated according to ).

[0078] The second position controller (400) is a component that, when a charging method using asymmetric three-phase current is selected by the charging method selector (100), generates a torque command to reduce the difference between the rotor position command of the motor (3) and the rotor position and outputs it to the three-phase current reference generator (500).

[0079] The three-phase current reference generator (500) is a component that generates a stator phase current command for synthesizing a torque command received from the second position controller (400) when a charging method using asymmetric three-phase current is selected by the charging method selector (100).

[0080] For example, the three-phase current reference generator (500) can generate a stator phase current command according to the angle of the stator current command calculated by the torque command generated by the second position controller (400) and the charger current command.

[0081] The current controller (600) controls the stator phase current (i) of the motor (3). abcs ) is a component that controls the stator phase current command generated by the 2-phase current reference generator (300) or the stator phase current command generated by the 3-phase current reference generator (500) to follow.

[0082] As one example, the current controller (600) may be configured to apply a two-phase switching signal having the same DC value to the inverter (2) constituting the motor-inverter system.

[0083] This configuration is described more specifically and exemplarily with further reference to FIG. 5 as follows.

[0084] FIG. 5 is a diagram showing a charging method using asymmetric two-phase current in one embodiment of the present invention.

[0085] Referring further to FIG. 5, unlike conventional technology that uses all three-phase currents for charging, a method of performing charging using only two-phase currents is exemplified.

[0086] According to this method, control is performed in the same way as a two-phase boost converter, and a switching signal is not applied to the switch corresponding to the phase not used for charging. FIG. 5 discloses an example in which phase a is open, and a 180-degree phase difference voltage is applied to phases b and c.

[0087] According to this method, phase current ripple can be significantly reduced during DC-DC power conversion with a step-up ratio of 2, which is common in the industry. Additionally, motor losses are affected by phase current ripple, and if the ripple is reduced according to this method, losses are reduced, thereby increasing charging efficiency.

[0088] This method reduces the magnitude of the phase current ripple by applying voltage to make the large differential mode inductance effective, instead of using a small zero-sequence inductance.

[0089] This method prevents unintended rotation of the rotor during charging by controlling the phase current combination so that no torque is generated even when current flows through the two phases, and this combination varies depending on the angle of the rotor and the charging current.

[0090] In this method, the phase difference of the applied two-phase voltage may not be 180 degrees.

[0091] The average of the phase voltages applied to the three phases is defined as the zero-sequence voltage (ZSV). In a typical system where the magnitude of the zero-sequence inductance is small compared to the differential mode inductance, if the zero-sequence voltage is applied instantaneously, it leads to a large phase current ripple, which leads to AC loss in the motor (3). In a system with a step-up ratio of 2, applying a two-phase charging method can instantaneously eliminate the zero-sequence voltage, thereby reducing AC loss in the motor (3) and increasing charging efficiency.

[0092] As another example, the current controller (600) may be configured to apply a three-phase switching signal having different DC values ​​to the inverter (2) constituting the motor-inverter system.

[0093] This configuration is described more specifically and exemplarily with further reference to FIG. 6 as follows.

[0094] FIG. 6 is a diagram showing a charging method using asymmetric three-phase current in one embodiment of the present invention.

[0095] Referring further to Fig. 6, a charging method using all three phases for charging is exemplified.

[0096] This charging method includes position control technology that allows the motor (3) to maintain a stationary state, unlike conventional technology which does not perform torque suppression control and can cause unintended rotation of the rotor during charging.

[0097] Unlike conventional technology that controls the DC components of the three-phase current equally, this method is a charging method that uses all three phases for charging but controls the DC values ​​of each phase current to non-identical values.

[0098] Figure 6 illustrates a case where the phase difference between the voltages applied to the three phases is 120 degrees, but this method can be applied at any angle where the phase difference between the voltages applied to the three phases is not 120 degrees.

[0099] For example, the current controller (600) controls the stator dq-axis current (i) of the motor (3) to satisfy the zero-torque condition expressed by the following mathematical formula 1. dqs It can be configured to control ).

[0100] [Mathematical Formula 1]

[0101]

[0102] T e is the total torque, pp is the number of pole pairs, and Ψ fis the magnetic flux linkage of the motor, and Ψ n L is the stator n-axis flux linkage, Ld is the stator d-axis inductance, Lq is the stator q-axis inductance, and θ r is the rotor position, i ds is the stator d-axis current, and i qs is the stator q-axis current, and i ns is the stator n-axis current.

[0103] As a more specific example, the current controller (600) is the stator n-axis current (i ns ) to -i * ch It can be configured to suppress rotor rotation of the motor (3) during charging by controlling it to / 3 and controlling the stator d-axis current and stator q-axis current on a 0-torque hyperbola that satisfies the 0-torque condition.

[0104] This configuration is described more specifically and exemplarily with further reference to FIGS. 7 and FIGS. 8 as follows.

[0105] FIG. 7 is a diagram showing the torque sign on the dq plane when ∂Ψn / ∂θr < 0 in one embodiment of the present invention, and FIG. 8 is a diagram showing the torque sign on the dq plane when ∂Ψn / ∂θr > 0 in one embodiment of the present invention.

[0106] Referring further to FIGS. 7 and FIGS. 8, a magnetic field is generated by the charging current flowing through the stator of the motor (3), and since this generates torque during charging, it is necessary to suppress torque during charging to prevent safety issues such as the electric vehicle moving during charging.

[0107] FIGS. 7 and 8 schematically illustrate current conditions satisfying the above 0-torque condition, wherein the charger current i ch (-3i ns , i ns The torque distribution according to the n-axis current is shown in the dqn coordinate system.

[0108] d-axis current (i ds), q-axis current(i qs ) total torque (T e If controlled so that ) lies on the hyperbola satisfying 0, charging can be performed while satisfying 0-torque. That is, the n-axis current (-i ch / 3), d-axis current (i ds ), q-axis current(i qs If ) is controlled to be located on a hyperbola, the rotation of the rotor during charging can be suppressed.

[0109] For example, when a charging method using asymmetric two-phase current is selected for the current controller (600), the rotor position (θ) of the motor (3) r ) can be controlled to have a preset value.

[0110] This configuration is described more specifically and exemplarily with further reference to FIG. 11 as follows.

[0111] FIG. 11 is a diagram showing a comparison of efficiency measurement results between a three-phase charging method and a two-phase charging method according to the motor rotor position in one embodiment of the present invention.

[0112] Referring to the vehicle in Fig. 11, the efficiency of the two-phase charging method (SC2) and the three-phase charging method (SC3) is the rotor position (θ r It varies depending on the ) and, especially in the case of the 2-phase charging method (SC2), the difference between the maximum efficiency and the minimum efficiency is large.

[0113] As a result of the measurement, the efficiency of the two-phase charging method (SC2) is the rotor position (θ r It was confirmed to be high when ) is 0, 2π / 3, and 4π / 3, and rotor position (θ during vehicle parking r The efficiency of two-phase charging can be increased by automatically parking so that ) becomes 0, 2π / 3, or 4π / 3. In an exemplary parking environment, the electric vehicle can be parked in a state with the highest charging efficiency by moving its position forward or backward by up to 1.5 cm.

[0114] As explained in detail above, according to the present invention, an asymmetric phase current-based charging controller is provided that can improve charging efficiency and suppress torque caused by charging current by controlling the charging process using an asymmetric phase current in an integrated charger utilizing a motor-inverter system to charge a high-voltage battery with a low-voltage charger.

[0115] [Explanation of the symbol]

[0116] 1: Integrated charger

[0117] 2: Inverter

[0118] 3: Motor

[0119] 10: Asymmetric phase current-based charge controller

[0120] 100: Charging method selector

[0121] 200: 1st position controller

[0122] 300: 2-phase current reference generator

[0123] 400: Second position controller

[0124] 500: 3-phase current reference generator

[0125] 600: Current controller

Claims

1. A charging controller utilizing asymmetric phase current in an integrated charger utilizing a motor-inverter system equipped in the electric vehicle to charge the battery of the electric vehicle, wherein A charging method selector that selects a charging method using one of asymmetric two-phase current and asymmetric three-phase current according to the status information of the above motor-inverter system; When the charging method using the asymmetric two-phase current is selected by the charging method selector, the rotor position command (θ) of the motor r * ) and rotor position (θ r Torque command (T) to reduce the difference of ) e * A first position controller that generates ); When a charging method using the asymmetric two-phase current is selected by the charging method selector, a stator phase current command (i) for synthesizing the torque command received from the first position controller * abcs A two-phase current reference generator that generates ) When a charging method using the asymmetric three-phase current is selected by the charging method selector, a second position controller that generates a torque command to reduce the difference between the rotor position command of the motor and the rotor position; When a charging method using the asymmetric three-phase current is selected by the charging method selector, a three-phase current reference generator that generates a stator phase current command for synthesizing a torque command received from the second position controller; and The stator phase current (i) of the above motor abcs An asymmetric phase current-based charge controller comprising a current controller that controls the stator phase current command generated by the two-phase current reference generator or the stator phase current command generated by the three-phase current reference generator.

2. In Paragraph 1, The above status information is the battery voltage (V bat ) and charger voltage (V ch The voltage step-up ratio (V) which is the ratio of ) bat / V ch ), charger current(i ch An asymmetric phase current-based charging controller characterized by including one or more of the size of ) and the rotor position of the motor.

3. In Paragraph 2, The above two-phase current reference generator is the angle (θ) of the stator current command calculated by the torque command generated by the first position controller. i * =atan(i * βs / i * αs )) and charger current command(i * ch Generates the above stator phase current command according to ), and An asymmetric phase current-based charging controller characterized in that the above three-phase current reference generator generates the stator phase current command according to the angle of the stator current command calculated by the torque command generated by the second position controller and the charger current command.

4. In Paragraph 1, An asymmetric phase current-based charging controller characterized by the current controller applying a two-phase switching signal having the same DC value to an inverter constituting the motor-inverter system.

5. In Paragraph 1, An asymmetric phase current-based charging controller characterized by the current controller applying a three-phase switching signal having unequal DC values ​​to an inverter constituting the motor-inverter system.

6. In Paragraph 1, The above current controller satisfies the 0-torque condition expressed by Equation 1 below, so that the stator dq-axis current (i) of the motor dqs Asymmetric phase current-based charge controller characterized by controlling ) [Mathematical Formula 1] T e is the total torque, pp is the number of pole pairs, and Ψ f is the magnetic flux linkage of the motor, and Ψ n L is the stator n-axis flux linkage, Ld is the stator d-axis inductance, Lq is the stator q-axis inductance, and θ r is the rotor position, i ds is the stator d-axis current, and i qs is the stator q-axis current, and i ns is the stator n-axis current.

7. In Paragraph 6, The above current controller is the stator n-axis current (i ns ) to -i * ch An asymmetric phase current-based charging controller characterized by controlling to / 3 and controlling the stator d-axis current and the stator q-axis current along a 0-torque hyperbola that satisfies the 0-torque condition, thereby suppressing rotor rotation of the motor during charging.

8. In Paragraph 1, The above current controller, when the charging method using the asymmetric two-phase current is selected, the rotor position (θ) of the motor r An asymmetric phase current-based charging controller characterized by controlling ) to have a preset value.

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