Device for supplying power from a vehicle battery to the outside of the vehicle and vehicle bidirectional charging device comprising such a device

Abstract

The present invention relates to an apparatus for supplying power from a vehicle battery to the outside of a vehicle and a vehicle bidirectional charging device including the same. The apparatus includes an inverter circuit having a bridge circuit including a plurality of switching elements, and converting received direct current into alternating current by switching of the switching elements and outputting the alternating current, and a controller controlling an on / off state of each of the switching elements by pulse width modulation. When a value of an output alternating current flowing to a load is greater than a preset reference value, or a value of an input direct current flowing to the inverter is greater than a preset reference value, the controller changes a duty ratio of each of the switching elements to reduce an output alternating voltage output from the inverter. When a value of the reduced output alternating voltage is equal to or less than the preset reference value, the controller stops a power conversion operation of the inverter.

Description

Technical Field

[0001] The present invention relates to a device for supplying power from a vehicle battery to an external part of the vehicle and a bidirectional charging device for a vehicle including the device, and more specifically, to such a device for supplying power from a vehicle battery to an external part of the vehicle and a bidirectional charging device for a vehicle including the device, wherein when providing power stored in the vehicle's internal battery to an external load, hardware burnout can be prevented while ensuring power supply robustness. Background Technology

[0002] Typically, plug-in hybrid electric vehicles (PHEVs) or electric vehicles have large-capacity batteries for storing the electricity required by the motors that drive the vehicle, and may include charging equipment for converting external power according to the battery voltage and thereby charging the battery. Conventional charging equipment has a unidirectional power flow, thus converting external power and supplying it to the battery. However, recently it has been proposed to replace the diodes in the power factor correction circuit located within the charging equipment with switching elements capable of on / off control, so that the power factor correction circuit operates as an inverter, thereby converting battery power into alternating current and outputting that alternating current to the outside of the vehicle (so-called vehicle-to-load (V2L) technology).

[0003] When power is supplied from a vehicle using V2L technology to an external load, overload is likely to occur due to the limited power capacity of the vehicle and the load current amplitude being determined by the external load. Therefore, vehicles using V2L technology need to have the function of suspending V2L operation in the event of an overload to prevent hardware burnout. However, suspending V2L operation even at the initial stage of V2L operation, during load changes, or due to minor inrush currents caused by load characteristics would cause significant inconvenience to users of the V2L function.

[0004] The above description of the background technology is only for the purpose of helping to understand the background of the present invention, and those skilled in the art should not regard it as corresponding to known prior art. Summary of the Invention

[0005] Therefore, one aspect of the present invention is to provide an apparatus for supplying power from a vehicle battery to an external part of the vehicle, and a vehicle bidirectional charging device including the apparatus, wherein during V2L operation of supplying power stored in the vehicle's internal battery to an external load, hardware burnout can be prevented while ensuring power supply robustness.

[0006] According to one aspect of the present invention, an apparatus for supplying power from a battery in a vehicle to an external location is provided. The apparatus is configured to receive direct current (DC) from the battery in the vehicle, convert the DC to alternating current (AC), and output the AC to a load external to the vehicle. Specifically, the apparatus may include an inverter circuit and a controller. The inverter circuit includes a bridge circuit containing multiple switching elements and is configured to convert the received DC to AC by switching the switching elements and output AC. The controller is configured to control the on / off state of each switching element using pulse width modulation. The controller is configured to: change the duty cycle of each switching element to reduce the output AC voltage from the inverter circuit when the value of the output AC current to the load is greater than a preset reference value, or the value of the input DC current to the inverter circuit is greater than a preset reference value; and stop the power conversion operation of the inverter circuit when the reduced output AC voltage is equal to or less than the preset reference value.

[0007] In an exemplary embodiment of the present invention, the controller may include: a voltage controller, a current controller, and a current upper limit setting section. The voltage controller is configured to generate a d-axis current command value for converging the error between the d-axis voltage value of the output AC voltage from the inverter circuit to the load and a preset d-axis voltage command value to zero. The current controller is configured to determine the duty cycle of each switching element for converging the error between the d-axis current value of the output AC current from the inverter circuit to the load and the d-axis current command value to zero. The current upper limit setting section is configured to set the upper limit of the d-axis current command value such that when the value of the output AC current is greater than a preset reference value or the value of the input DC current is greater than a preset reference value, the upper limit of the d-axis current command value is reduced.

[0008] In an exemplary embodiment of the present invention, the controller may further include a comparator configured to output a command to stop the power conversion operation of the inverter circuit when the d-axis voltage value of the output AC voltage is equal to or less than a preset lower limit setting value for the d-axis voltage of the output AC voltage. Furthermore, the upper limit setting portion may include an output AC current limiting portion configured to generate a first d-axis current upper limit correction value for converging the error between a preset root-mean-square (RMS) limit value for the output AC current and a sensed value of the output AC current to zero. The upper limit setting portion is configured to determine the upper limit of the d-axis current command value by adding the first d-axis current upper limit correction value to a d-axis current limit value derived from the preset RMS limit value for the output AC current.

[0009] The d-axis current limit value can be obtained by multiplying the preset root mean square value of the output AC current by... To determine this. Additionally, the output AC current limiting section may include a limiter configured to limit the first d-axis current upper limit correction value to zero or a negative value, and then add the first d-axis current upper limit correction value to the d-axis current limit value.

[0010] The current upper limit setting section may include an input DC current limiting section, which is configured to generate a second d-axis current upper limit correction value to converge the error between a preset input DC current limit value and the average value of the sensed input DC current from the battery input to the inverter circuit to zero, and the current upper limit setting section is configured to determine the upper limit of the d-axis current command value by adding the second d-axis current upper limit correction value to a d-axis current limit value derived from a limit value for a preset root mean square value of the output AC current.

[0011] Additionally, the d-axis current limit value can be calculated by multiplying the preset root mean square value of the output AC current by... The current upper limit setting section can be configured to: divide the preset maximum battery output by the average value of the input DC voltage; and set the smaller value selected from the preset input DC current limit value (considering hardware characteristics) and the value obtained by division as the input DC current limit value. The input DC current limiting section may include a limiter configured to limit the second d-axis current upper limit correction value to zero or a negative value, by adding the second d-axis current upper limit correction value to the d-axis current limit value.

[0012] According to one aspect of the present invention, a bidirectional charging device for a vehicle is provided. In a battery charging mode within the vehicle, the bidirectional charging device receives alternating current (AC) from outside the vehicle, converts the AC to direct current (DC), and provides the DC as charging power for the battery. In a load supply mode, it receives DC from the battery, converts the DC to AC, and outputs the AC to a load outside the vehicle. The bidirectional charging device may include: an inverter-type power factor correction circuit, a bidirectional DC-DC converter, and a controller. The inverter-type power factor correction circuit includes a bridge circuit containing multiple switching elements and is configured to: convert external AC to DC in charging mode and convert DC to AC in load supply mode by switching the switching elements. The bidirectional DC-DC converter is configured to: convert the voltage of the DC converted by the inverter-type power factor correction circuit to the battery charging voltage in charging mode and convert the battery voltage in load supply mode, and provide the converted battery voltage to the inverter-type power factor correction circuit. The controller is configured to control the on / off state of each switching element by pulse width modulation.

[0013] The controller is further configured to: in load power supply mode, when the value of the output AC current to the load is greater than a preset reference value or the value of the input DC current to the inverter-type power factor correction circuit is greater than a preset reference value, change the duty cycle of each switching element to reduce the output AC voltage output from the inverter-type power factor correction circuit; when the value of the reduced output AC voltage is equal to or less than the preset reference value, stop the load power supply mode.

[0014] In an exemplary embodiment of the present invention, the controller may include: a voltage controller, a current controller, and a current upper limit setting section. The voltage controller is configured to generate a d-axis current command value in load power supply mode, which is used to converge the error between the d-axis voltage value of the output AC voltage from the inverter-type power factor correction circuit to the load and a preset d-axis voltage command value to zero. The current controller is configured to determine, in load power supply mode, the duty cycle of each switching element for converging the error between the d-axis current value of the output AC current from the inverter-type power factor correction circuit to the load and the d-axis current command value to zero. The current upper limit setting section is configured to set the upper limit of the d-axis current command value in load power supply mode such that when the value of the output AC current is greater than a preset reference value or the value of the input DC current is greater than a preset reference value, the upper limit of the d-axis current command value is reduced.

[0015] The controller may further include a comparator configured to, in load-supply mode, output a command to stop the power conversion operation of the inverter-type power factor correction circuit when the d-axis voltage value of the output AC voltage is equal to or less than a preset d-axis voltage lower limit setting value for the output AC voltage. Additionally, the current upper limit setting section may include an output AC current limiting section configured to, in load-supply mode, generate a first d-axis current upper limit correction value to converge the error between a preset root-mean-square (RMS) limit value for the output AC current and a sensed value of the output AC current to zero. Furthermore, the current upper limit setting section is configured to, in load-supply mode, determine the upper limit of the d-axis current command value by adding the first d-axis current upper limit correction value to a d-axis current limit value derived from the preset RMS limit value for the output AC current.

[0016] The d-axis current limit value can be obtained by multiplying the preset root mean square value of the output AC current by... To determine. In an exemplary embodiment of the present invention, the output AC current limiting section may include a limiter configured to, in load-powered mode, limit a first d-axis current upper limit correction value to be added to the d-axis current limit value when the first d-axis current upper limit correction value is zero or negative.

[0017] Additionally, the current upper limit setting section may include an input DC current limiting section, which is configured to generate a second d-axis current upper limit correction value in load power supply mode to converge the error between a preset input DC current limit value and the average value of the sensed input DC current from the battery input to the inverter-type power factor correction circuit to zero. The current upper limit setting section is also configured to determine the upper limit of the d-axis current command value in load power supply mode by adding the second d-axis current upper limit correction value to a d-axis current limit value derived from a limit value for a preset root mean square value of the output AC current.

[0018] In an exemplary embodiment of the present invention, the d-axis current limit value can be obtained by multiplying a preset root mean square value of the output AC current by... To determine this, the current upper limit setting section can be configured to: in load power supply mode, divide the preset maximum battery output by the average value of the input DC voltage; and set the smaller value selected from the preset input DC current limit value considering hardware characteristics and the value obtained by division as the input DC current limit value. In an exemplary embodiment of the present invention, the input DC current limiting section may include a limiter configured to, in load power supply mode, limit the second d-axis current upper limit correction value to be added to the d-axis current limit value when the second d-axis current upper limit correction value is zero or negative.

[0019] The advantages of the device for supplying power from the vehicle battery to the outside of the vehicle, and the bidirectional charging equipment for the vehicle including the device, are as follows: In cases such as temporary overload, the power supply is not immediately interrupted, but rather the amplitude of the output AC voltage is gradually reduced while maintaining power supply. Power supply is only interrupted when the amplitude of the reduced output AC voltage eventually becomes equal to or lower than a configured reference. This prevents inconvenience to the user due to power interruption in cases of temporary overload.

[0020] Furthermore, the device for supplying power from the vehicle battery to the outside of the vehicle, and the bidirectional charging equipment for the vehicle including the device, have the advantage that stable overload protection can be performed regardless of the type of load supplied from the vehicle battery in the event of a sustained overload. Since the AC power supplied from the vehicle inevitably depends on the characteristics of the load, this overload protection function for various loads enables a more stable implementation of the V2L function for supplying power from the vehicle to the load.

[0021] The beneficial effects that can be obtained from the present invention are not limited to those described above, and those skilled in the art will clearly understand other beneficial effects not mentioned herein. Attached Figure Description

[0022] The above and other aspects, features and advantages of the invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which:

[0023] Figure 1 This is a circuit diagram illustrating an example of a bidirectional charging device for a vehicle, including means for supplying power from a battery in the vehicle to an external part of the vehicle according to an embodiment of the present invention.

[0024] Figure 2 This is a block diagram more specifically illustrating a controller for a device for supplying power from a battery in a vehicle to an external part of the vehicle according to an embodiment of the present invention;

[0025] Figure 3 This is a block diagram more specifically illustrating the output AC current limiting portion of a controller in an apparatus for supplying power from a battery in a vehicle to an external part of the vehicle according to an embodiment of the present invention.

[0026] Figure 4 This is a block diagram, more specifically illustrating, the input DC current limiting portion of a controller in a device for supplying power from a battery in a vehicle to an external location according to an embodiment of the present invention; and

[0027] Figures 5 to 9 These are waveform diagrams showing simulation results of the operation of devices for supplying power from a battery in a vehicle to the outside of the vehicle according to various embodiments of the present invention. Detailed Implementation

[0028] It should be understood that the term "vehicle" or "of a vehicle" or other similar terms as used herein generally include motor vehicles, such as passenger cars including sport utility vehicles (SUVs), buses, trucks, and various commercial vehicles, vessels including various boats and ships, aircraft, etc., and includes hybrid vehicles, electric vehicles, plug-in hybrid electric vehicles, hydrogen-powered vehicles, and other alternative fuel vehicles (e.g., vehicles derived from non-fossil fuels). As mentioned herein, a hybrid vehicle is a vehicle with two or more power sources, such as a vehicle powered by both gasoline and electricity.

[0029] While the exemplary embodiments are described as using multiple units to perform the exemplary process, it should be understood that the exemplary process may also be performed by one or more modules. Furthermore, it should be understood that the term controller / control unit refers to a hardware device including a memory and a processor, and that the hardware device is specifically programmed to perform the processes described herein. The memory is configured to store modules, and the processor is specifically configured to run said modules to perform one or more processes, which will be further described below.

[0030] Furthermore, the control logic of the present invention can be implemented as a non-transitory computer-readable medium on a computer-readable medium, which contains executable program instructions that are executed by a processor, controller / control unit, etc. Examples of computer-readable media include, but are not limited to, ROM, RAM, optical disc (CD)-ROM, magnetic tape, floppy disk, flash drive, smart card, and optical data storage device. The computer-readable recording medium can also be distributed across a network-connected computer system, such that the computer-readable medium is stored and executed in a distributed manner, for example, via a telematics server or a controller area network (CAN).

[0031] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used herein, the singular forms “a,” “an,” and “described” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will also be understood that when the terms “comprising” and / or “including” are used in this specification, they indicate the presence of the stated features, values, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, values, steps, operations, elements, components, and / or groups thereof. As used herein, the term “and / or” includes any and all combinations of one or more of the associated enumerated items.

[0032] Unless otherwise stated or obvious from the context, as used herein, the term "approximately" is understood to mean within the normal tolerance range in the field, such as within the standard deviation of two means. "Approximately" can be understood as within 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, 0.5%, 0.1%, 0.05%, or 0.01% of the specified value. Unless the context clearly indicates otherwise, all numerical values ​​provided herein are modified by the term "approximately".

[0033] In the following, devices for supplying power from a battery in a vehicle to the outside of the vehicle according to various embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0034] Figure 1 This is a circuit diagram illustrating an example of a bidirectional charging device for a vehicle, including means for supplying power from a battery in the vehicle to an external part of the vehicle according to an embodiment of the present invention. Figure 1 The example shown is a bidirectional charging device installed in a vehicle, which is a device for converting direct current stored in the vehicle battery into three-phase alternating current and supplying the three-phase alternating current to the outside of the vehicle, or a device for converting three-phase alternating current from the power grid into direct current capable of charging the battery and supplying the direct current to the battery.

[0035] like Figure 1As shown, a bidirectional charging device that implements an embodiment of the present invention for supplying power from a battery in a vehicle to an external part of the vehicle may include: an inverter-type power factor correction circuit 10 and a bidirectional DC-DC converter 20. The inverter-type power factor correction circuit 10 includes inductors L1 to L3 and a bridge circuit including multiple switching elements S1 to S6. The bidirectional DC-DC converter 20 is connected between the battery 30 and the DC input / output terminals of the inverter-type power factor correction circuit 10.

[0036] Figure 1 The diagram illustrates an example of a bidirectional DC-DC converter 20 implemented as an LLC resonant converter topology for determining the voltage amplitude supplied to the battery 30 via frequency modulation control of the switching elements S7 to S10 therein. However, the bidirectional DC-DC converter 20 can be replaced by a bidirectional converter with another topology (e.g., a phase-shifted full-bridge converter).

[0037] When charging battery 30, the mains AC voltage V input through AC input / output terminals 10a, 10b and 10c is... ac1 V ac2 and V ac3 The DC voltage input from the inverter-type power factor correction circuit 10 is converted to DC and then input to the bidirectional DC-DC converter 20. The bidirectional DC-DC converter 20 can, through appropriate control, convert the DC voltage input from the power factor correction circuit 10 into a voltage of sufficient amplitude to charge the battery 30. The DC voltage, whose amplitude has been converted by the bidirectional DC-DC converter 20, can then be applied to the battery 30, thereby charging the battery 30.

[0038] On the other hand, in order to output the power of the battery 30 in the form of AC, the bidirectional DC-DC converter 20 can be configured to appropriately change the voltage amplitude of the battery 30 and provide the changed voltage to the inverter-type power factor correction circuit 10. The inverter-type power factor correction circuit 10, which has received the DC voltage transmitted by the bidirectional DC-DC converter 20 through the DC input / output terminals 11a and 11b, can be configured to control the on / off operation of the switching elements S1 to S6 by applying a conventional inverter control algorithm to generate three-phase AC power, and then output the three-phase AC power through the AC input / output terminals 10a, 10b and 10c.

[0039] According to various embodiments of the present invention, the means for supplying power from a battery in a vehicle to an external part of the vehicle is a means for appropriately controlling the on / off operation of switching elements S1 to S6 included in the inverter-type power factor correction circuit 10 of the bidirectional charging device to provide alternating current to an external load.

[0040] Various embodiments of the present invention may include a controller 100 configured to operate switching elements in an inverter-type power factor correction circuit 10. The controller 100 may be configured to receive predetermined set values ​​for multiple parameters required for operation of the control device, and sensed values ​​of multiple parameters actually detected by sensors or the like installed in the device. The controller 100 may also be configured to apply the input set values ​​and sensed values ​​to a preset algorithm so that the device can perform appropriate operations.

[0041] The controller 100 included in various embodiments of the present invention may be implemented using a non-volatile memory (not shown) and a processor (not shown). The non-volatile memory is configured to store data related to an algorithm or software instructions for executing the algorithm, the algorithm being configured to control the on / off operation of switching elements S1 to S6, and the processor is configured to use the data stored in the memory to perform the operations described below. The memory and processor may be implemented as separate chips or as a single chip, and one or more processors may be provided.

[0042] Figure 2 This is a block diagram more specifically illustrating a controller for a device for supplying power from a battery in a vehicle to an external part of the vehicle according to an embodiment of the present invention.

[0043] refer to Figure 2 According to an embodiment of the present invention, a controller 100 for a device for supplying power from a battery in a vehicle to an external part of the vehicle may include: a voltage controller 110 and a current controller 120, and a current upper limit setting section 140. The voltage controller 110 and the current controller 120 are configured to operate the switching elements S1-S6 of an inverter-type power factor correction circuit 10 by performing voltage and current control based on the d-axis voltage (V_d) of the output AC voltage sensed value and the d-axis current (I_d) of the output AC current sensed value. The d-axis voltage (V_d) of the output AC voltage sensed value and the d-axis current (I_d) of the output AC current sensed value are generated by performing a dq transformation on the sensed value (Vac_sen) of the output AC voltage of a device for converting DC power in the battery to AC power and outputting AC power. The current upper limit setting section 140 is configured to determine the upper limit of the d-axis current command value (I_d_ref) output from the voltage controller 110. Furthermore, the controller 100 may further include a comparator 150, which is configured to output a command to stop the operation of the device when the d-axis voltage (V_d) of the output AC voltage sensing value becomes less than a preset d-axis voltage lower limit (V_d_Lower Lmt).

[0044] The voltage controller 110 can be configured to receive the error between the d-axis voltage (V_d) of the output AC voltage sense value and a preset d-axis voltage command value (V_d_ref), and can generate a d-axis current command value (I_d_ref) to converge the error between the two values ​​to zero. The voltage controller 110 can be implemented in the form of a proportional-integral controller 111, which is well known in the relevant art.

[0045] Specifically, in an embodiment of the present invention, the voltage controller 110 may be configured to receive a current upper limit value determined by the current upper limit value setting portion 140, and to generate and output a d-axis current command value (I_d_ref) that is equal to or less than the current upper limit value. In other words, the voltage controller 110 may further include a limiter 112 configured to limit the output so that when the d-axis current command value generated by proportional-integral control or the like is greater than the current upper limit value determined by the current upper limit value setting portion 140, the current upper limit value is output.

[0046] The current controller 120 can be configured to receive the error between the d-axis current command value (I_d_ref) output by the voltage controller 110 and the d-axis current (I_d) of the output AC current sense value, and the current controller 120 can be configured to generate duty cycle values ​​for the switching elements S1 to S6 to converge the error between the two values ​​to zero. The voltage and current control techniques described above for operating the switching elements S1 to S6 of the bridge circuit included in the inverter circuit are well known in the relevant art, and therefore their additional detailed description will be omitted.

[0047] The current upper limit setting section 140 may include an output AC current limiting section 141 and an input DC current limiting section 142. The output AC current limiting section 141 is configured to generate a first d-axis current upper limit correction value (Iac_d_cor1) for converging the error between a preset output AC current limit value (Iac_rms_Lmt) and an output AC current sensing value (Iac_rms_sen) to zero. The input DC current limiting section 142 is configured to generate a second d-axis current upper limit correction value (Iac_d_cor2) for converging the error between a preset input DC current limit value (Idc_Lmt) and the average value (Idc_AVG) of an input DC current sensing value to zero. The current upper limit setting section 140 can be configured to determine the upper limit value (I_d_ref_max) of the d-axis current command value (I_d_ref) by applying the first d-axis current upper limit correction value (Iac_d_cor1) and the second d-axis current upper limit correction value (Iac_d_cor2) to a preset d-axis current limit value (Iac_d_Lmt) of the output AC current, and the current upper limit setting section 140 can provide the upper limit value (I_d_ref_max) to the voltage controller 110.

[0048] In the description of various embodiments of the present invention, the term "output" may refer to the inverter circuit used to convert the direct current (DC) power from battery 30 into alternating current (AC) power (e.g., Figure 1 The inverter-type power factor correction circuit 10 in the circuit provides AC current to the load. The term "input" refers to the current supplied from the battery 30 to the inverter circuit (e.g., ...). Figure 1 The inverter-type power factor correction circuit 10) in the middle provides the input of DC current. In other words, the reference for the output and input is the inverter circuit used to convert the power.

[0049] The current upper limit setting section 140 can be configured to multiply the preset output AC current limit value (Iac_rms_Lmt) by a multiplier (M). To generate the d-axis current limit value (Iac_d_Lmt).

[0050] Typically, in inverter control, voltage and current control can be performed by transforming the AC voltage and current to the dq coordinate system. Specifically, to achieve control that makes the phase difference between the AC voltage and AC current zero, a dq phase-locked loop is used to control the q-axis voltage to zero, thus ensuring that the d-axis value of the AC current under normal conditions equals the peak value of the AC current. Therefore, the output AC current limit value (Iac_rms_Lmt), expressed as the root mean square (rms) value, can be multiplied by... This is used to generate the d-axis current limit value (Iac_d_Lmt) as the d-axis component of the output AC current limit value.

[0051] The current upper limit setting section 140 can be configured to control the reduction of the d-axis current limit value (Iac_d_Lmt) by applying a first d-axis current upper limit correction value (Iac_d_cor1) generated by the output AC current limiting section 141 and a second d-axis current upper limit correction value (Iac_d_cor2) generated by the input DC current limiting section 142 to the d-axis current limit value. The first d-axis current upper limit correction value (Iac_d_cor1) and the second d-axis current upper limit correction value (Iac_d_cor2) can be negative values.

[0052] In other words, when it is necessary to reduce the output due to an increase in the output AC current sensing value (Iac_rms_sen) or an increase in the average value of the input DC current sensing value (Idc_AVG), the upper limit of the current command value can be reduced through current control, thereby reducing the AC current output from the device. Figure 2 The adders A1 to A6, multiplier (M), and divider (D) shown are normal components used to simply perform addition, subtraction, and multiplication, and therefore will not be described in detail separately.

[0053] Figure 3 This is a block diagram more specifically illustrating the output AC current limiting portion of a controller in a device for supplying power from a battery in a vehicle to an external location according to an embodiment of the present invention. Reference Figure 3 The output AC current limiting section 141 may include a proportional-integral (PI) controller 1411 and a limiter 1412, wherein the PI controller 1411 is configured to perform error elimination control to converge the error between a preset output AC current limit value (Iac_rms_Lmt) and an output AC current sense value (Iac_rms_sen) to zero; and the limiter 1412 is configured to limit the output of the PI controller 1411 to output only negative values.

[0054] If the output of voltage controller 110 is limited only by the d-axis current limit value (Iac_d_Lmt) of the AC current, then when the AC load current (output AC current) contains harmonic components or the load impedance includes inductive or capacitive components, the d-axis component value of the AC load current is less than the peak value of the AC load current. Therefore, even when output current limiting is required, the limiting cannot be properly implemented. Even in this case, the output AC current limiting section 141 is set to perform normal output current limiting.

[0055] In the output AC current limiting section 141, when the root mean square value (Iac_rms_sen) of the sensed output AC current is greater than the preset output AC current limit value (Iac_rms_Lmt), the error input to the controller 1411 has a negative value. Therefore, the value output from the controller 1411 is negative. The upper limit of the current command output from the voltage controller 110 is reduced by adding the output value of the controller 1411 to the d-axis component (Iac_d_Lmt) of the preset output AC current limit value.

[0056] Limiter 1412 can be configured to limit the output to only negative values. In other words, limiter 1412 can ensure that the first d-axis current upper limit correction value (Iac_d_cor1) output by the output AC current limiting section 141 is only negative. Limiter 1412 can only add the value output by controller 1411 to the d-axis component (Iac_d_Lmt) of the preset output AC current limit value when the value output by controller 1411 is negative, thereby preventing the upper limit of the current command value output by voltage controller 110 from increasing and reducing the current command value.

[0057] Therefore, the output AC current limiting section 141 can be configured to limit a preset output AC current limit value (Iac_rms_Lmt) by utilizing the root mean square value of the output AC current. Thus, even when harmonic components are present or when there is a phase difference between the AC current and the AC voltage, the output AC current limiting section 141 can limit the output value of the inverter voltage controller.

[0058] Figure 4 This is a block diagram, more specifically illustrating, the input DC current limiting portion of a controller in a device for supplying power from a battery in a vehicle to an external location according to an embodiment of the present invention. Reference Figure 4 The input DC current limiting section 142 may include a PI controller 1421 and a limiter 1422, wherein the PI controller 1421 is configured to perform error elimination control to converge the error between a preset input DC current limit value (Idc_Lmt) and the average value of the input DC current (Idc_AVG) to zero; and the limiter 1422 is configured to limit the output of the PI controller 1421 to output only negative values.

[0059] The output AC current limiting section 141 can be configured to limit the root mean square value of the output AC current to a value less than the limit value. However, the output AC current limiting section 141 cannot respond to the case where the DC current input from the battery 30 to the device is output at a value equal to or greater than the limit value. Therefore, the input DC current limiting section 142 can be configured to limit the output of the input DC current when the input DC current is output at a value equal to or greater than the limit value predetermined considering hardware conditions.

[0060] Embodiments of the present invention may include a divider (D) and a minimum output unit (Min) to set an input DC current limit value. The divider (D) may be configured to divide a preset maximum battery output (Po_Max) by the average value of the input DC voltage supplied from the battery 30, and the minimum output unit (Min) may output the smaller of a preset input DC current limit value (Idc_Lmt_Hw) and the value input from the divider as an input DC current limit value (Idc_Lmt) that takes into account hardware characteristics.

[0061] Controller 1421 can be configured to perform control to converge the error to zero. In response to determining that the average input DC current (Idc_AVG) is greater than the input DC current limit (Idc_Lmt), the error input to controller 1421 can have a negative value, and controller 1421 can be configured to output a negative second d-axis current upper limit correction value (Iac_d_cor2) to converge the corresponding error to zero. When the second d-axis current upper limit correction value (Iac_d_cor2) output by controller 1421 is added to the d-axis component (Iac_d_Lmt) of the preset output AC current limit, the upper limit of the current command output by voltage controller 110 decreases.

[0062] Limiter 1422 can be configured to limit the output to only negative values. In other words, limiter 1422 can ensure that the second d-axis current upper limit correction value (Iac_d_cor2) output by the input DC current limiting section 142 is only negative. Limiter 1422 can only add the value output by controller 1421 to the d-axis component (Iac_d_Lmt) of the preset output AC current limit value when the value output by controller 1421 is negative, thereby preventing the upper limit of the current command value output by voltage controller 110 from increasing and reducing the current command value.

[0063] As described above, the upper limit of the d-axis current command output by the voltage controller 110 can be limited by the upper limit value (I_d_ref_max) of the output current command, which is calculated by applying the first d-axis current upper limit correction value (Iac_d_cor1) and the second d-axis current upper limit correction value (Iac_d_cor2) generated by the output AC current limiting section 141 and the input DC current limiting section 142. If no limitation is applied, that is, if the output of each of the output AC current limiting section 141 and the input DC current limiting section 142 has a zero value, the upper limit of the d-axis current command output by the voltage controller 110 can correspond to multiplying the preset root mean square value (Iac_rms_Lmt) of the output AC current limit value by... The value obtained.

[0064] When the output AC current from the device is too large, thus requiring the output AC current to be limited, or when the value of the input DC current is greater than the preset reference value considering the hardware conditions of the device, thus requiring the input DC current to be limited, the output AC current limiting section 141 or the input DC current limiting section 142 outputs a negative value, and therefore the upper limit of the current command output by the voltage controller 110 gradually decreases.

[0065] In this situation, the d-axis component (I_d) of the output AC current sense value is greater than the reduced output current command upper limit (I_d_ref_max), and the error value input to the current controller 120 is negative. Therefore, the current controller 120 can be configured to change the duty cycle value and output a reduced current. As a result, when the output AC current or input DC current is too large to maintain the limiting condition, the duty cycle value continues to decrease, and thus the d-axis component (V_d) of the output AC voltage also continues to decrease.

[0066] Comparator 150 can be configured to compare the d-axis component value (V_d) of the output AC voltage with a preset lower limit setting value (V_d_Lower Lmt) of the d-axis component of the output AC voltage under limited conditions. When the d-axis component value (V_d) of the output AC voltage is equal to or less than the preset lower limit setting value (V_d_Lower Lmt), the limited condition is maintained without being released, and therefore this situation can be considered dangerous. Thus, comparator 150 can shut down the operation of the device to prevent power from being supplied from the vehicle's battery 30 to the outside of the vehicle.

[0067] The rate (slope) of decrease in the d-axis component (V_d) of the output AC voltage can vary depending on the characteristics of the load. For example, in the case of a constant current load, the load current is constant regardless of the output AC voltage value. However, in the case of a constant resistance load, the resistance is constant, so according to Ohm's law, if the amplitude of the output AC voltage decreases, the load current will also decrease. Therefore, compared to the case of a constant current load, the current controller input error is smaller in the case of a constant resistance load, resulting in a slower decrease in the output AC voltage. Conversely, in the case of a constant power load, the power, which is the product of voltage and current, is constant, so if the output AC voltage decreases, the load current will increase. Therefore, in the case of a constant power load, the current controller input error is larger, allowing the output AC voltage to decrease more quickly through control.

[0068] As mentioned above, the output characteristics of a device used to supply power from a battery in a vehicle to the outside of the vehicle can be determined solely by the load characteristics. Therefore, appropriate limiting operations are required for various types of loads.

[0069] Figures 5 to 9 These are waveform diagrams illustrating simulation results of the operation of devices for supplying power from a battery in a vehicle to an external location according to various embodiments of the present invention. Figures 5 to 9 In the diagram, the horizontal axis represents time, and the vertical axis represents the physical value of each parameter.

[0070] Figure 5 This is a waveform diagram showing the operation under constant current overload conditions. For example... Figure 5 As shown, it can be determined that when an overload occurs, the current command (I_d_ref) output by the voltage controller 110 decreases the first d-axis current upper limit correction value (Iac_d_cor1) generated by the output AC current limiting section 141. Furthermore, it can be determined that since the load is a constant current load, the sensed value (Iac_sen) and its d-axis value (I_d) of the output AC current remain constant. Additionally, it can be determined that the duty cycle value output by the current controller 120 decreases by adjusting the output limit, and the d-axis value (V_d) of the output AC voltage decreases accordingly. Furthermore, it can be determined that when the d-axis value (V_d) of the output AC voltage is equal to or less than the preset d-axis voltage lower limit setting value (V_d_Lower Lmt) of the output AC voltage, the operation of the device stops.

[0071] Figure 6 This is a waveform diagram showing the operation under constant resistance overload conditions. For example... Figure 6As shown, it can be determined that when an overload occurs, the current command (I_d_ref) output by the voltage controller 110 decreases the first d-axis current upper limit correction value (Iac_d_cor1) generated by the output AC current limiting section 141. Furthermore, it can be determined that since the load is a constant resistance load, the sensed value (Iac_sen) and its d-axis value (I_d) of the output AC current gradually decrease. Additionally, it can be determined that the duty cycle value output by the current controller 120 decreases by adjusting the output limit, and the d-axis value (V_d) of the output AC voltage decreases accordingly. Furthermore, it can be determined that when the d-axis value (V_d) of the output AC voltage is equal to or less than the preset d-axis voltage lower limit setting value (V_d_Lower Lmt) of the output AC voltage, the operation of the device stops.

[0072] Figure 7 This is a waveform diagram showing the operation under constant power overload conditions. For example... Figure 7 As shown, it can be determined that when an overload occurs, the current command (I_d_ref) output by the voltage controller 110 reduces the first d-axis current upper limit correction value (Iac_d_cor1) generated by the output AC current limiting section 141. Furthermore, it can be determined that the duty cycle value output by the current controller 120 decreases due to the adjustment of the output limiting, and the d-axis value (V_d) of the output AC voltage decreases accordingly.

[0073] Furthermore, it can be determined that, since the load is a constant power load, if the amplitude of the output AC voltage decreases, the sensed value (Iac_sen) and its d-axis value (I_d) of the output AC current gradually increase. Additionally, it can be determined that the device stops operating when the d-axis value (V_d) of the output AC voltage is equal to or less than the preset lower limit setting value (V_d_LowerLmt) of the d-axis component of the output AC voltage.

[0074] Figure 8 This is a waveform diagram showing the operation under capacitive constant current overload conditions. For example... Figure 8As shown, it can be determined that when an overload occurs, the current command (I_d_ref) output by the voltage controller 110 decreases the first d-axis current upper limit correction value (Iac_d_cor1) generated by the output AC current limiting section 141. Furthermore, it can be determined that since the load is a constant current load, the sensed value (Iac_sen) and its d-axis value (I_d) of the output AC current remain constant. Additionally, it can be determined that the duty cycle value output by the current controller 120 decreases by adjusting the output limit, and the d-axis value (V_d) of the output AC voltage decreases accordingly. Furthermore, it can be determined that when the d-axis value (V_d) of the output AC voltage is equal to or less than the preset lower limit setting value (V_d_Lower Lmt) of the d-axis component of the output AC voltage, the operation of the device stops.

[0075] Figure 9 This is a waveform diagram showing the operation of limiting the input DC current when an overload occurs. For example... Figure 9 As shown, it can be determined that when the input DC current is limited, the current command (I_d_ref) output by the voltage controller 110 reduces the second d-axis current upper limit correction value (Iac_d_cor2) generated by the input DC current limiting section 142, thereby reducing the duty cycle value output by the current controller 120.

[0076] Furthermore, it can be determined that the d-axis value (V_d) of the output AC voltage decreases due to the decrease in the duty cycle. Additionally, it can be determined that, since the load is a constant current load, the sensed value (Iac_sen) and its d-axis value (I_d) of the output AC current remain constant. Furthermore, it can be determined that the device stops operating when the d-axis value (V_d) of the output AC voltage is equal to or less than the preset lower limit setting value (V_d_Lower Lmt) of the d-axis component of the output AC voltage.

[0077] As described above, the apparatus for supplying power from a vehicle battery to an external location according to various embodiments of the present invention can perform the following operations: in cases of temporary overload, it maintains power supply while gradually reducing the amplitude of the output AC voltage, rather than immediately stopping the power supply; then, when the amplitude of the reduced output AC voltage eventually equals or falls below a preset reference, it stops supplying power. Through this operation, the apparatus for supplying power from a vehicle battery to an external location according to various embodiments of the present invention can stop supplying power in the event of a temporary overload due to interference, thereby preventing inconvenience to the user. Furthermore, the apparatus for supplying power from a vehicle battery to an external location according to various embodiments of the present invention can achieve stable overload protection regardless of the type of load supplied from the vehicle battery.

[0078] In the following description and illustration of specific embodiments of the invention, it will be apparent to those skilled in the art that various modifications and improvements may be made to the invention without departing from the appended claims.

Claims

1. A device for supplying power from a battery in a vehicle to an external part of the vehicle, wherein, The device receives direct current (DC) from a battery in the vehicle, converts the DC to alternating current (AC), and outputs the AC to a load outside the vehicle. The device includes: An inverter circuit includes a bridge circuit with multiple switching elements, wherein the inverter circuit is configured to convert received direct current (DC) into alternating current (AC) by switching the switching elements and to output AC; and The controller is configured to control the on / off state of each switching element via pulse width modulation. The controller is further configured as follows: In response to determining that the value of the output AC current to the load is greater than a preset reference value, or the value of the input DC current to the inverter circuit is greater than a preset reference value, the duty cycle of each switching element is changed to reduce the output AC voltage output from the inverter circuit. In response to determining that the reduced output AC voltage is equal to or less than a preset reference value, the power conversion operation of the inverter circuit is stopped.

2. The apparatus for supplying power from a battery in a vehicle to an external part of the vehicle according to claim 1, wherein, The controller includes: A voltage controller configured to generate a d-axis current command value for which the error between the d-axis voltage value of the output AC voltage from the inverter circuit to the load and a preset d-axis voltage command value converges to zero. A current controller configured to determine the duty cycle of each switching element to which the error between the d-axis current value and the d-axis current command value used for the output AC current from the inverter circuit to the load converges to zero; and The current upper limit setting section is configured to reduce the upper limit of the d-axis current command value when the output AC current value is greater than the preset reference value or the input DC current value is greater than the preset reference value.

3. The apparatus for supplying power from a battery in a vehicle to an external location according to claim 2, wherein, The controller further includes a comparator configured to output a command to stop the power conversion operation of the inverter circuit in response to determining that the d-axis voltage value of the output AC voltage is equal to or less than a preset lower limit setting value for the d-axis voltage of the output AC voltage.

4. The apparatus for supplying power from a battery in a vehicle to an external part of the vehicle according to claim 2, wherein, The current upper limit setting section includes an output AC current limiting section, which is configured to generate a first d-axis current upper limit correction value to converge the error between the limit value of the preset root mean square value of the output AC current and the sensed value of the output AC current to zero. The current upper limit setting section is configured to determine the upper limit of the d-axis current command value by adding the first d-axis current upper limit correction value to the d-axis current limit value derived from the limit value of the preset root mean square value of the output AC current.

5. The apparatus for supplying power from a battery in a vehicle to an external location according to claim 4, wherein, The d-axis current limit value is obtained by multiplying the preset root mean square value of the output AC current by... To determine.

6. The apparatus for supplying power from a battery in a vehicle to an external location according to claim 4, wherein, The output AC current limiting section includes a limiter configured to limit the first d-axis current upper limit correction value to zero or a negative number, and then add the first d-axis current upper limit correction value to the d-axis current limit value.

7. The apparatus for supplying power from a battery in a vehicle to an external part of the vehicle according to claim 2, wherein, The current upper limit setting section includes an input DC current limiting section, which is configured to generate a second d-axis current upper limit correction value to converge the error between a preset input DC current limit value and the average value of the sensed input DC current from the battery input to the inverter circuit to zero. The current upper limit setting section is configured to determine the upper limit of the d-axis current command value by adding the second d-axis current upper limit correction value to a d-axis current limit value derived from a limit value for a preset root mean square value of the output AC current.

8. The apparatus for supplying power from a battery in a vehicle to an external part of the vehicle according to claim 7, wherein, The d-axis current limit value is obtained by multiplying the preset root mean square value of the output AC current by... To determine.

9. The apparatus for supplying power from a battery in a vehicle to an external location according to claim 7, wherein, The current upper limit setting section is configured as follows: Divide the preset maximum battery output by the average value of the input DC voltage; The smaller value selected from the preset input DC current limit value that takes into account hardware characteristics and the value obtained by division will be set as the input DC current limit value.

10. The apparatus for supplying power from a battery in a vehicle to an external part of the vehicle according to claim 7, wherein, The input DC current limiting section includes a limiter configured to limit the second d-axis current upper limit correction value to zero or a negative value, and then add the second d-axis current upper limit correction value to the d-axis current limit value.

11. A bidirectional charging device for a vehicle, wherein in a battery charging mode within the vehicle, the bidirectional charging device receives alternating current (AC) from outside the vehicle, converts the AC to direct current (DC), and provides the DC as charging power for the battery; and in a load supply mode, receives DC from the battery, converts the DC to AC, and outputs the AC to a load outside the vehicle, the bidirectional charging device comprising: An inverter-type power factor correction circuit includes a bridge circuit with multiple switching elements and is configured to convert external AC power to DC power in charging mode and DC power to AC power in load power supply mode by switching the switching elements. A bidirectional DC-DC converter is configured to: in charging mode, convert the voltage of DC power converted by the inverter-type power factor correction circuit into the charging voltage of the battery; in load power supply mode, convert the voltage of the battery and provide the converted battery voltage to the inverter-type power factor correction circuit. as well as The controller is configured to control the on / off state of each switching element via pulse width modulation. The controller is configured as follows: In load power supply mode, in response to determining that the value of the output AC current to the load is greater than a preset reference value or the value of the input DC current to the inverter-type power factor correction circuit is greater than a preset reference value, the duty cycle of each switching element is changed to reduce the output AC voltage output from the inverter-type power factor correction circuit. In response to determining that the reduced output AC voltage is equal to or less than a preset reference value, the load power supply mode is stopped.

12. The bidirectional charging device for a vehicle according to claim 11, wherein, The controller includes: The voltage controller is configured to generate, in load power supply mode, a d-axis current command value that brings the error between the d-axis voltage value of the output AC voltage from the inverter-type power factor correction circuit to the load and the preset d-axis voltage command value to zero. A current controller configured to, in load-supply mode, determine the duty cycle of each switching element to which the error between the d-axis current value and the d-axis current command value of the output AC current from the inverter-type power factor correction circuit to the load converges to zero; and The current upper limit setting section is configured as follows: In load power supply mode, the upper limit of the d-axis current command value is set to decrease in response to determining that the value of the output AC current is greater than the preset reference value or the value of the input DC current is greater than the preset reference value.

13. The bidirectional charging device for a vehicle according to claim 12, wherein, The controller further includes a comparator configured to, in load power supply mode, output a command to stop the power conversion operation of the inverter-type power factor correction circuit when the d-axis voltage value of the output AC voltage is equal to or less than a preset lower limit setting value for the d-axis voltage of the output AC voltage.

14. The bidirectional charging device for a vehicle according to claim 12, wherein, The current upper limit setting section includes an output AC current limiting section, which is configured to: in load power supply mode, generate a first d-axis current upper limit correction value to converge the error between the limit value of the preset root mean square value of the output AC current and the sensed value of the output AC current to zero; and the current upper limit setting section is configured to: in load power supply mode, determine the upper limit of the d-axis current command value by adding the first d-axis current upper limit correction value to the d-axis current limit value derived from the limit value of the preset root mean square value of the output AC current.

15. The bidirectional charging device for a vehicle according to claim 14, wherein, The d-axis current limit value is obtained by multiplying the preset root mean square value of the output AC current by... To determine.

16. The bidirectional charging device for a vehicle according to claim 14, wherein, The output AC current limiting section includes a limiter configured to: in load power supply mode, limit the first d-axis current upper limit correction value to zero or negative, and add the first d-axis current upper limit correction value to the d-axis current limit value.

17. The bidirectional charging device for a vehicle according to claim 12, wherein, The current upper limit setting section includes an input DC current limiting section, which is configured to: in load power supply mode, generate a second d-axis current upper limit correction value to converge the error between a preset input DC current limit value and the average value of the sensed input DC current from the battery input to the inverter-type power factor correction circuit to zero; and the current upper limit setting section is configured to: in load power supply mode, determine the upper limit of the d-axis current command value by adding the second d-axis current upper limit correction value to a d-axis current limit value derived from a limit value for a preset root mean square value of the output AC current.

18. The bidirectional charging device for a vehicle according to claim 17, wherein, The d-axis current limit value is obtained by multiplying the preset root mean square value of the output AC current by... To determine.

19. The bidirectional charging device for a vehicle according to claim 17, wherein, The current upper limit setting section is configured as follows: in load power supply mode, the preset maximum battery output is divided by the average value of the input DC voltage; the smaller value selected from the preset input DC current limit value that takes into account hardware characteristics and the value obtained by division is set as the input DC current limit value.

20. The bidirectional charging device for a vehicle according to claim 17, wherein, The input DC current limiting section includes a limiter configured to: in load power supply mode, limit the second d-axis current upper limit correction value to the sum of the second d-axis current upper limit correction value and the d-axis current limit value when the second d-axis current upper limit correction value is zero or negative.

Images