TW201925800A - On board charge device and operating method thereof - Google Patents

Abstract

The present disclosure provides an on board charge device and an operating method thereof. The on-board charging device includes an AC connector, an AC to DC converter and a detection circuit. The AC connector is configured to connect electric vehicle supply equipment (EVSE), so that a protective earth terminal of EVSE is electrically connected to a protective earth terminal of the on board charge device. The AC-to-DC converter is electrically connected to the AC connector, and the AC to DC converter is configured to convert an AC voltage provided by the EVSE into a DC voltage. The AC to DC converter has a reference ground terminal. The detection circuit is based on the voltage difference between the protective earth terminal of the on board charge device and the reference ground terminal of the AC to DC converter to output a detection voltage. The detection voltage reflects whether the protective earth terminal of the EVSE is abnormal or not.

Description

Vehicle-mounted charging device and operation method thereof

The present invention relates to a device and method, and in particular to a vehicle-mounted charging device and an operation method thereof.

Since the invention of fuel-fueled vehicles, it has indeed improved the convenience of human action. With the advancement of technology, fuel-fueled vehicles have been rapidly mass-produced, making fuel-fueled vehicles one of the tools that people rely on in their lives. Today's global warming is severe, causing climate anomalies, and raising global awareness of energy conservation. However, excessive use of fuel-fueled cars, burning a large amount of gasoline caused air pollution, thereby destroying the ecology. Therefore, all countries are actively encouraging the development of new energy vehicles (such as electric vehicles or hybrid electric vehicles) to reduce their dependence on oil.

The rapid popularity of electric vehicles is bound to drive the rapid development of electric vehicle charging equipment (EVSE). However, the quality of ground fault detection of EVSEs around the world is uneven, increasing the probability of electric shock for electric vehicles during charging.

The invention provides a vehicle-mounted charging device and an operation method thereof, which improve the problems of the prior art.

In an embodiment of the present invention, the vehicle-mounted charging device provided by the present invention includes an AC connector, an AC-to-DC converter, and a detection circuit. The AC connector is used to connect electric vehicle charging equipment, so that the protective ground terminal of the electric vehicle charging equipment is electrically connected to the protective ground terminal of the vehicle charging device. The AC-to-DC converter is electrically connected to the AC connector. The AC-to-DC converter is used to convert the AC voltage provided by the electric vehicle charging equipment into a DC voltage. The AC-DC converter has a reference ground terminal. The detection circuit outputs a detection voltage based on the voltage difference between the protective ground terminal of the vehicle charging device and the reference ground terminal of the AC-to-DC converter, and the detection voltage reflects whether the protective ground terminal of the electric vehicle charging device is abnormal.

In an embodiment of the invention, the vehicle-mounted charging device further includes a controller. When the detected voltage is lower than a preset threshold voltage, the controller is used to determine that the protective ground terminal of the electric vehicle charging device is abnormal.

In an embodiment of the present invention, when the detection voltage is higher than a preset threshold voltage, the controller determines that the protective ground terminal of the electric vehicle charging device is normal.

In an embodiment of the invention, the detection circuit includes a voltage dividing circuit, a buffer, an amplifier, and a filter. The voltage dividing circuit is electrically connected to the protective ground terminal of the vehicle charging device and the reference ground terminal of the AC / DC converter. The voltage dividing circuit divides the voltage between the protective ground terminal and the reference ground terminal into a voltage signal. The buffer is electrically connected to a voltage dividing circuit, and the buffer receives a voltage signal. The amplifier is electrically connected to the buffer, and the amplifier receives the voltage signal outputted by the buffer. The filter is electrically connected to the amplifier, and the filter filters the voltage signal amplified by the amplifier to output a detection voltage.

In an embodiment of the present invention, the voltage dividing circuit includes a first resistor, a second resistor, and a filter circuit. One end of the first resistor is electrically connected to the protective ground terminal of the vehicle-mounted charging device. The second resistor is connected in series with the first resistor. One end of the second resistor is electrically connected to the other end of the first resistor, and the other end of the second resistor is electrically connected to the reference ground terminal of the AC-to-DC converter. The filter circuit is connected in parallel with the second resistor.

In an embodiment of the invention, the buffer is a voltage follower.

In an embodiment of the invention, the amplifier is a differential amplifier.

In an embodiment of the invention, the filter is a low-pass filter.

In an embodiment of the invention, the vehicle-mounted charging device further includes an isolation stage, a DC-to-DC converter, and an output filter. The isolation stage is electrically connected to the AC-to-DC converter, the DC-to-DC converter is electrically connected to the isolation stage, and the output filter is electrically connected to the DC-to-DC converter. The DC voltage output by the AC-to-DC converter is converted by the isolation stage and the DC-to-DC converter and then filtered by an output filter to provide a vehicle charging voltage to the vehicle.

In an embodiment of the present invention, the method for operating a vehicle-mounted charging device provided by the present invention includes: when an AC connector is connected to an electric vehicle charging device, a protective ground terminal of the electric vehicle charging device is electrically connected to the protective ground of the vehicle charging device Terminal, based on the voltage difference between the protective ground terminal of the vehicle charging device and the reference ground terminal of the AC-to-DC converter to output a detection voltage; and based on the detection voltage, determine whether the protective ground terminal of the electric vehicle charging device is abnormal .

In an embodiment of the present invention, the step of determining whether the protective ground terminal of the electric vehicle charging equipment is abnormal or not includes determining that the protective ground terminal of the electric vehicle charging equipment is abnormal when the detection voltage is lower than a preset threshold voltage.

In an embodiment of the present invention, the step of determining whether the protective ground terminal of the electric vehicle charging equipment is abnormal or not includes: determining that the protective ground terminal of the electric vehicle charging equipment is normal when the detection voltage is higher than a preset threshold voltage.

In an embodiment of the present invention, the operation method further includes: when the AC connector is connected to the electric vehicle charging device, determining whether the AC voltage provided by the electric vehicle charging device is higher than a predetermined voltage; and when the electric vehicle charging device provides When the AC voltage is higher than a predetermined voltage, it is determined whether the AC voltage falls within a first voltage interval.

In an embodiment of the present invention, the step of determining whether the protective ground terminal of the electric vehicle charging device is abnormal according to the detection voltage includes: determining whether the detection voltage is lower than the first voltage when the AC voltage falls within the first voltage interval; A preset threshold voltage; when the detection voltage is lower than the first preset threshold voltage, determining whether a period during which the detection voltage continues to be lower than the first preset threshold voltage exceeds a first predetermined time; and After a period of a preset threshold voltage has exceeded the first predetermined time, it is determined that the protective ground terminal of the electric vehicle charging device is abnormal.

In an embodiment of the present invention, the step of determining whether the protective ground terminal of the electric vehicle charging device is abnormal according to the detected voltage includes: when the AC voltage does not fall in the first voltage interval but falls in the second voltage interval, Determine whether the detection voltage is lower than a second preset threshold voltage; when the detection voltage is lower than the second preset threshold voltage, determine whether the period during which the detection voltage continues to be lower than the second preset threshold voltage exceeds a second predetermined time ; And after the period when the detection voltage continues to be lower than the second preset threshold voltage has exceeded the second predetermined time, it is determined that the protective ground terminal of the electric vehicle charging device is abnormal.

In summary, the technical solution of the present invention has obvious advantages and beneficial effects compared with the prior art. With the vehicle-mounted charging device and the method for operating the same, a function of detecting whether a protective ground terminal of an electric vehicle charging device is faulty is added to the vehicle-mounted charging device, thereby reducing the risk of electric shock to personnel.

The above description will be described in detail in the following embodiments, and further explanation will be provided for the technical solution of the present invention.

In order to make the description of the present invention more detailed and complete, reference may be made to the accompanying drawings and various embodiments described below. The same numbers in the drawings represent the same or similar elements. On the other hand, well-known elements and steps have not been described in the embodiments, so as to avoid unnecessary limitation to the present invention.

In the embodiments and the scope of patent application, the description related to "electrical connection" can refer to an element that is indirectly electrically coupled to another element through other elements, or that an element is directly and electrically connected to another element without passing through other elements. One component.

In the embodiments and the scope of the patent application, the description of "electrical connection" may refer to a component that is electrically connected to another component indirectly through other components, or a component does not need to be physically connected to another component through other components. One component.

In the embodiments and the scope of patent application, unless there is a special limitation on the article in the text, "a" and "the" can refer to a single or plural.

As used in this article, "about," "approximately," or "roughly" is used to modify any quantity that can vary slightly, but such slight changes do not change its essence. Unless otherwise specified in the embodiments, the error range of the value modified by "about", "approximately" or "approximately" is generally allowed within 20%, preferably 10% Within, and more preferably within five percent.

FIG. 1 is a block diagram of a vehicle-mounted charging device 100 according to an embodiment of the present invention. As shown in FIG. 1, the in-vehicle charging device 100 is applied to a vehicle 170. For example, the vehicle 170 may be an electric vehicle, a hybrid electric vehicle, or another rechargeable vehicle.

In FIG. 1, the vehicle charging device 100 may include an AC connector 111, an AC-to-DC converter 112, an isolation stage 113, a DC-to-DC converter 114, an output filter 115, a high-voltage connector 116, and a first controller. 121, the second controller 122, the third controller 123, the signal connector 124, the first signal connection device 131, the second signal connection device 132, the auxiliary power source 140, and the detection circuit 160. For example, the isolation stage 113 may be an LLC resonant converter, the DC-to-DC converter 114 may be a step-down converter, and the first controller 121, the second controller 122, and the third controller 123 may be respective microcomputers. The controller, the first signal connection device 131 and the second signal connection device 132 may be respective signal connection chips.

In FIG. 1, the AC-to-DC converter 112 may include an input filter 151 (such as an electromagnetic interference filter) and a power factor correction circuit 152. Architecturally, the input filter 151 is electrically connected to the AC connector 111, and the power factor correction circuit 152 is electrically connected to the input filter 151.

In FIG. 1, the AC connector 111, the AC-to-DC converter 112, the primary side of the isolation stage 113, and the first controller 121 are disposed on the high-voltage primary side 110 of the vehicle-mounted charging device 100 and the secondary side of the isolation stage 113. The DC-to-DC converter 114, the output filter 115, the high-voltage connector 116, and the second controller 122 are disposed on the high-voltage secondary side 120 of the vehicle-mounted charging device 100. The third controller 123 and the signal connector 124 are disposed on the vehicle. The low-voltage side 130 of the charging device 100.

When in use, the auxiliary power source 140 supplies power to the first controller 121, the second controller 122, and the third controller 123, so that the first controller 121, the second controller 122, and the third controller 123 perform high voltage once. Control of corresponding elements in the side 110, the high-voltage secondary side 120, and the low-voltage side 130.

The first signal connection device 131 electrically connects the first controller 121 on the high-voltage primary side 110 and the second controller 122 on the high-voltage secondary side 120 as the first controller 121 and the second controller on different voltage sides. The medium of signal transmission between 122. The second signal connection device 132 electrically connects the second controller 122 on the high-voltage secondary side 120 and the third controller 123 on the low-voltage side 130 as the second controller 122 and the third controller 123 on different voltage sides. The medium of signal transmission between.

The high-voltage primary side 110 and the high-voltage secondary side 120 mainly convert the AC voltage provided by the electric vehicle charging device 190 into a vehicle charging voltage that the vehicle 170 can accept.

Architecturally, the AC connector 111 is electrically connected to the AC-to-DC converter 112, the AC-to-DC converter 112 is electrically connected to the isolation stage 113, and the isolation stage 113 is electrically connected to the DC-to-DC converter 114, and the DC-to-DC converter 114 The output filter 115 is electrically connected to the high-voltage connector 116.

After the AC connector 111 is connected to the electric vehicle charging device 190, the AC-to-DC converter 112 converts the AC voltage provided by the electric vehicle charging device into a DC voltage, and the DC voltage output by the AC-to-DC converter 112 is separated from the DC through the isolation stage 113 The DC converter 114 is converted and then filtered by the output filter 115 to provide a vehicle charging voltage. The high-voltage connector 116 outputs the vehicle charging voltage to the vehicle 170. It is worth mentioning that the isolation stage 113 and the DC-to-DC converter 114 can be two independent power converters. For example, the isolation stage 113 can be an LLC resonant converter and the DC-to-DC converter 114 can be a step-down converter. On the contrary, the isolation stage 113 and the DC-to-DC converter 114 can also be replaced by a first-level power converter. For example, the isolation stage 113 and the DC-to-DC converter 114 can be replaced by a one-stage LLC resonant converter to provide a stable output. Adjust the design according to actual needs. The foregoing converter is an example, and is not limited thereto. The LLC resonant converter may also be replaced by a full-bridge phase-shift converter or other types of converters.

Specifically, the electric vehicle charging device 190 has a live line L, a neutral line N, and a protective ground terminal PE. When the AC connector 111 is connected to the electric vehicle charging device 190, the AC connector 111 is connected to the live line L, the neutral line N and the protective ground terminal PE, so that the protective ground terminal PE of the electric vehicle charging device 190 is electrically connected to the protection of the vehicle charging device 100 Ground terminal PE. The AC-to-DC converter 112 receives the AC voltage from the live line L and the neutral line N through the AC connector 111 and converts the AC voltage into a DC voltage. The AC-to-DC converter 112 needs to have a reference ground terminal 150. This reference-ground terminal 150 is a voltage reference level for the voltage detection and control of the AC-to-DC converter 112. For example, the DC of the AC-to-DC converter 112 can be The negative terminal of the output voltage.

It should be understood that the protective ground terminal PE of the electric vehicle charging device 190 and the reference ground terminal 150 of the AC-to-DC converter 112 are different ground terminals. In the application of the power supply system, the exposed and conductive part of the device is usually connected through the protective ground terminal PE to form a complete equipotential connection system. Referring to FIG. 1, the protective ground terminal PE of the in-vehicle charging device 100 is connected to the protective ground terminal PE of the electric vehicle charging device 190 through the AC connector 111 to achieve a good ground. On the other hand, the reference ground terminal 150 is a primary-side reference ground terminal of the high-voltage primary side 110 of the vehicle-mounted charging device 100.

However, the ground detection quality of EVSEs around the world is uneven. In order to prevent the danger of electric shock to the vehicle 170 during charging, the detection circuit 160 is based on the protective ground terminal PE of the vehicle charging device 100 and the AC-to-DC converter 112. The voltage difference between the reference ground terminal 150 is used to output a detection voltage. The detection voltage reflects whether the protective ground terminal PE of the electric vehicle charging device 190 is abnormal. The so-called abnormality refers to whether the protective ground terminal PE is maintained with the ground. Well connected. In addition, as mentioned earlier, the protective ground terminal PE of the vehicle charging device 100 is connected to the protective ground terminal PE of the electric vehicle charging device 190 through the AC connector 111, so the detection circuit 160 can choose the nearby vehicle charging device 100 for protection. The ground PE is used as the detection point.

In an embodiment, the detection circuit 160 outputs the detection voltage to the first controller 121 of the high-voltage primary 110, and the first controller 121 transmits the value of the detection voltage to the high voltage through the first signal connection device 131 The second controller 122 of the secondary side 120, the second controller 122 transmits the value of the detection voltage to the third controller 123 of the low voltage side 130 through the second signal connection device 132, and the third controller 123 judges the detection Whether the voltage is lower than a preset threshold voltage. When the detected voltage is lower than the preset threshold voltage, the third controller 123 determines that the protective ground terminal PE of the electric vehicle charging device 190 is abnormal. Conversely, when the detection voltage is higher than a preset threshold voltage, the third controller 123 determines that the protective ground terminal PE of the electric vehicle charging device 190 is normal.

In other embodiments, the first controller 121 or the second controller 122 can also determine whether the detection voltage is lower than a preset threshold voltage, and those skilled in the art can flexibly adjust it according to actual needs.

It should be understood that the above-mentioned preset threshold voltage may be different from the controller (eg, the first controller 121, the second controller 122, and / or the third controller 123) by the system designer according to different conditions or component parameters that are determined to be abnormal. ) Set it in advance or adjust it flexibly by the user. For example, the system designer can consider the ground impedance greater than a certain value to be abnormal and adjust the threshold voltage accordingly.

If the protective ground terminal PE of the electric vehicle charging device 190 is abnormal, for example, the third controller 123 may output an abnormal signal to the vehicle 170 through the signal connector 124, so that the vehicle 170 performs a corresponding warning action (such as a warning sound, a warning Video, etc.) to warn people and reduce their risk of electric shock. Alternatively, the AC-to-DC converter 112 may be turned off by the first controller 121.

The following further explains the spirit and principle of the present invention. When the AC connector 111 is connected to the electric vehicle charging device 190, the AC-to-DC converter 112 receives the AC voltage from the live line L and the neutral line N and converts it into a DC voltage. The AC voltage will form One circuit has alternating positive and negative half cycles. Therefore, the reference ground terminal 150 of the AC-to-DC converter 112 will alternately have the same potential as the live line L or the neutral line N. If the protective ground terminal PE of the electric vehicle charging device 190 is normally grounded, Because the live line L or the neutral line N has a voltage difference to the protective ground terminal PE, the protective ground terminal PE and the reference ground terminal 150 also have a voltage difference, and this voltage difference is related to the voltage difference between the live line L and the neutral line N. Conversely, if the protective ground terminal PE of the electric vehicle charging device 190 is abnormally grounded, for example, it is not connected to the ground, so the live line L or the neutral line N does not have a voltage difference with the protective ground terminal PE, so the protective ground terminal PE and the reference ground terminal 150 are not. Voltage difference. The detection circuit 160 outputs a detection voltage based on the voltage difference between the protective ground terminal and the reference ground terminal. The detection voltage reflects whether the protective ground terminal of the electric vehicle charging device is abnormal.

In order to further explain the operation method of the detection circuit 160 described above, please refer to FIGS. 1 and 2 at the same time. FIG. 2 is a circuit diagram of a detection circuit 160 according to an embodiment of the present invention. As shown in FIG. 2, the detection circuit 160 includes a voltage dividing circuit 210, a buffer 220, an amplifier 230, and a filter 240.

Architecturally, the buffer 220 is electrically connected to the voltage dividing circuit 210, the amplifier 230 is electrically connected to the buffer 220, the filter 240 is electrically connected to the amplifier 230, and the first controller 121 is electrically connected to the filter 240. One end of the voltage dividing circuit 210 is electrically connected to the reference ground terminal 150 of the AC / DC converter 112, and the other end of the voltage dividing circuit 210 is used to electrically connect the protective ground terminal PE of the vehicle charging device 100. In use, the voltage dividing circuit 210 divides the voltage between the protective ground terminal PE and the reference ground terminal 150 into a voltage signal. The buffer 220 receives a voltage signal. The amplifier 230 receives a voltage signal outputted by the buffer 220. The filter 240 filters the voltage signal amplified by the amplifier 230 to output a detection voltage.

In FIG. 2, the voltage dividing circuit 210 includes a first resistor Ra, a second resistor Rb, and a filter circuit 212. Architecturally, one end of the first resistor Ra is electrically connected to the protective ground terminal PE of the vehicle-mounted charging device 100. The second resistor Rb is connected in series with the first resistor Ra. Specifically, one end of the second resistor Rb is electrically connected to the other end of the first resistor Ra, and the other end of the second resistor Rb is electrically connected to the AC pair. The reference ground terminal 150 of the DC converter 112. The filter circuit 212 is connected in parallel with the second resistor Rb.

In an embodiment of the present invention, as shown in FIG. 2, the filter circuit 212 includes a capacitor C4 and a diode D1. Architecturally, one end of the second resistor Rb is electrically connected to the first resistor Ra, the cathode of the diode D1 and one end of the capacitor C4, and the other end of the second resistor Rb is electrically connected to the AC-to-DC converter 112. Reference ground 150, the anode of diode D1 and the other end of capacitor C4. Capacitor C4 is used to suppress noise, and diode D1 is a clamping diode to protect the circuit.

In one embodiment of the present invention, the buffer 220 is a voltage follower. As shown in FIG. 2, the buffer 220 includes a first operational amplifier IC1, and an output terminal of the first operational amplifier IC1 is electrically connected to an inverting input terminal of the first operational amplifier IC1 and a non-inverting input terminal of the first operational amplifier IC1. The voltage signal output from the voltage divider circuit 210 is passed through the characteristic that the output impedance of the first operational amplifier IC1 is substantially zero, thereby eliminating the influence of the first resistor Ra and the second resistor Rb on the input impedance of the amplifier 230.

In one embodiment of the present invention, the amplifier 230 is a differential amplifier. As shown in FIG. 2, the amplifier 230 includes a second operational amplifier IC2, resistors R1 to R4, and capacitors C1 to C2. The two ends of the resistor R1 are electrically connected to the reference ground terminal 150 and the inverting input terminal of the second operational amplifier IC2. The two ends of the resistor R2 are electrically connected to the output terminal of the first operational amplifier IC1 and the second operational amplifier IC2. The non-inverting input terminal of the resistor R3 is electrically connected to the inverting input terminal of the second operational amplifier IC2 and the output terminal of the second operational amplifier IC2, and the two ends of the resistor R4 are electrically connected to the second operation. The non-inverting input terminal of the amplifier IC2 and the reference ground terminal 150, the two ends of the capacitor C1 are electrically connected to the inverting input terminal of the second operational amplifier IC2 and the output terminal of the second operational amplifier IC2, and the two ends of the capacitor C2 are electrically connected. The non-inverting input terminal of the second operational amplifier IC2 is electrically connected to the reference ground terminal 150. In use, the voltage signal is amplified by the second operational amplifier IC2.

In one embodiment of the present invention, the filter 240 is a low-pass filter. As shown in FIG. 2, the filter 240 includes a resistor R5 and a capacitor C3. The two ends of the resistor R5 are respectively electrically connected to the output end of the second operational amplifier IC2 and the first controller 121, and the two ends of the capacitor C3 are respectively electrically connected to the first controller 121 and the reference ground terminal 150. In use, the voltage level of the amplified voltage signal is smoothed through the filter 240 to facilitate the first controller 121 to read. It is worth mentioning that the spirit of the present invention aims to use a detection circuit to detect the voltage difference between the protective ground terminal and the reference ground terminal to reflect whether the protective ground terminal of the electric vehicle charging equipment is abnormal or not. The circuit shown in FIG. 2 It is only a preferred embodiment of the present invention, and is not limited thereto.

In order to further explain the operation method of the on-board charging device 100 described above, please refer to FIGS. 1 to 3 at the same time. FIG. 3 is a flowchart of an operation method 300 of the on-board charging device 100 according to an embodiment of the present invention. In general, in the operation method 300, when the AC connector 111 is connected to the electric vehicle charging device 190, the protective ground terminal PE of the electric vehicle charging device 190 is electrically connected to the protective ground terminal PE of the vehicle charging device 100, and the potentials of the two are approximately Similarly, the detection voltage is output based on the voltage difference between the protective ground terminal PE of the vehicle charging device 100 (or the protective ground terminal PE of the electric vehicle charging device 190) and the reference ground terminal 150 of the AC-to-DC converter 112; Next, based on the detected voltage, it is determined whether the protective ground terminal of the electric vehicle charging device 190 is abnormal PE or not. When the detection voltage is lower than the preset threshold voltage, the protective ground terminal PE of the electric vehicle charging device 190 is abnormal; on the contrary, when the detection voltage is higher than the preset threshold voltage, the protective ground terminal PE of the electric vehicle charging device 190 is normal .

Specifically, as shown in FIG. 3, the operation method 300 includes steps S301 to S307 (it should be understood that the steps mentioned in this embodiment can be adjusted according to actual needs, except for the order in which they are specifically described. It can be executed in the same order or partly at the same time).

In step S301, when the AC connector 111 is connected to the electric vehicle charging device 190, it is determined whether the AC voltage provided by the electric vehicle charging device 190 is higher than a predetermined voltage. When the AC voltage provided by the electric vehicle charging device 190 is higher than a predetermined voltage, it represents that the electric vehicle charging device 190 outputs a normal AC voltage. Conversely, when the AC voltage provided by the electric vehicle charging device 190 is lower than a predetermined voltage, it means that the voltage output by the electric vehicle charging device 190 is abnormal or no voltage is output, and the vehicle 170 cannot be charged, so the operation method 300 ends. For example, the predetermined voltage may be about 80V, and the normal AC voltage is generally about 110V or 220V, but the invention is not limited thereto.

In step S302, it is determined whether the AC voltage falls in the first voltage interval. When the AC voltage falls in the first voltage interval, in step S303, it is determined whether the detection voltage is lower than the first preset threshold voltage. When the detection voltage is lower than the first preset threshold voltage, in step S304, it is determined whether the period during which the detection voltage continues to fall below the first preset threshold voltage exceeds the first predetermined time to avoid misjudgment. After the period when the detection voltage continues to be lower than the first preset threshold voltage has exceeded the first predetermined time, in step S305, it is determined that the protective ground terminal PE of the electric vehicle charging device 190 is abnormal.

On the other hand, when the AC voltage does not fall in the first voltage interval but falls in the second voltage interval, in step S306, it is determined whether the detection voltage is lower than a second preset threshold voltage. When the detection voltage is lower than the second preset threshold voltage, in step S307, it is determined whether the period in which the detection voltage continues to be lower than the second preset threshold voltage exceeds a second predetermined time to avoid misjudgment. After the period when the detection voltage continues to be lower than the second preset threshold voltage has exceeded the second predetermined time, in step S305, it is determined that the protective ground terminal PE of the electric vehicle charging device 190 is abnormal.

It should be understood that the first voltage interval is different from the second voltage interval. For example, the first voltage interval may be approximately 90-132V, and is generally 110V; the second voltage interval may be approximately 200-240V, and is generally 220V. Alternatively, the first voltage interval may be approximately 200-240V, and conventionally is 220V; the second voltage interval may be approximately 90-132V, and conventionally is 110V, and those skilled in the art may flexibly adjust it according to actual needs.

As mentioned earlier, the voltage difference between the protective ground terminal PE and the reference ground terminal 150 is related to the voltage difference between the live line L and the neutral line N, so different preset thresholds can be selected according to the voltage interval of the AC voltage, such as the first The voltage interval is approximately 90-132V, and the first preset threshold voltage may be approximately 0.45V. Accordingly, if the second voltage interval is approximately 200-240V, the first preset threshold voltage may be approximately 0.9V. Alternatively, if the first voltage interval is approximately 200-240V, the first preset threshold voltage may be approximately 0.9V, and accordingly, if the second voltage interval is approximately 90-132V, the first preset threshold voltage may be approximately 0.45V .

It should be understood that the values of the above voltage ranges and the preset threshold voltages are only examples. In practice, the actual specific values can be different from the controller (such as: the first The controller 121, the second controller 122, and / or the third controller 123) are preset, or are flexibly adjusted by a user.

In summary, the technical solution of the present invention has obvious advantages and beneficial effects compared with the prior art. With the in-vehicle charging device 100 and the operating method 300 of the present invention, a function of detecting whether the protective ground terminal PE of the electric vehicle charging device 190 is faulty is added to the in-vehicle charging device, thereby reducing the risk of electric shock to persons.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention. Any person skilled in the art can make various modifications and retouches without departing from the spirit and scope of the present invention. Therefore, the protection of the present invention The scope shall be determined by the scope of the attached patent application.

In order to make the above and other objects, features, advantages, and embodiments of the present invention more comprehensible, the description of the attached symbols is as follows:

100‧‧‧ vehicle charging device

110‧‧‧high voltage primary

111‧‧‧AC connector

112‧‧‧AC to DC Converter

113‧‧‧Isolation level

114‧‧‧DC to DC Converter

115‧‧‧ output filter

116‧‧‧High Voltage Connector

120‧‧‧ high voltage secondary side

121‧‧‧The first controller

122‧‧‧Second controller

123‧‧‧Third Controller

124‧‧‧Signal connector

130‧‧‧Low voltage side

131‧‧‧first signal connection device

132‧‧‧Second signal connection device

140‧‧‧ auxiliary power

150‧‧‧reference ground

151‧‧‧input filter

152‧‧‧Power factor correction circuit

160‧‧‧detection circuit

170‧‧‧ Vehicle

190‧‧‧ Electric vehicle charging equipment

210‧‧‧Voltage Dividing Circuit

212‧‧‧filter circuit

220‧‧‧Buffer

230‧‧‧ amplifier

240‧‧‧Filter

300‧‧‧Operation method

S301 ~ S307‧‧‧step

C1 ~ C4‧‧‧Capacitor

D1‧‧‧diode

IC1‧‧‧The first operational amplifier

IC2‧‧‧Second Operational Amplifier

L‧‧‧FireWire

N‧‧‧Zero

PE‧‧‧ protective ground terminal

Ra‧‧‧first resistor

Rb‧‧‧Second resistor

R1 ~ R5‧‧‧ resistor

In order to make the above and other objects, features, advantages, and embodiments of the present invention more comprehensible, the description of the drawings is as follows: FIG. 1 is a block diagram of a vehicle-mounted charging device according to an embodiment of the present invention; FIG. 2 is a circuit diagram of a detection circuit according to another embodiment of the present invention; and FIG. 3 is a flowchart of an operation method of a vehicle-mounted charging device according to an embodiment of the present invention.

Claims (15)

An on-board charging device includes: an AC connector for connecting an electric vehicle charging device to electrically connect a protective ground terminal of the electric vehicle charging device to a protective ground terminal of the on-board charging device; an AC-to-DC conversion The AC-to-DC converter is electrically connected to the AC connector. The AC-to-DC converter is used to convert the AC voltage provided by the electric vehicle charging equipment into a DC voltage. The AC-DC converter has a reference ground terminal; and a detection circuit based on The voltage difference between the protective ground terminal of the vehicle charging device and the reference ground terminal of the AC-to-DC converter to output a detection voltage, the detection voltage reflects the protective ground terminal of the electric vehicle charging device Exception or not. The on-board charging device according to claim 1, further comprising: a controller for determining that the protective ground terminal of the electric vehicle charging device is abnormal when the detected voltage is lower than a preset threshold voltage. The on-board charging device according to claim 2, wherein when the detection voltage is higher than the preset threshold voltage, the controller determines that the protective ground terminal of the electric vehicle charging device is normal. The vehicle-mounted charging device according to claim 1, wherein the detection circuit includes: a voltage dividing circuit, which electrically connects the protective ground terminal of the vehicle-mounted charging device and the reference ground terminal of the AC / DC converter, the branch The voltage dividing circuit divides the voltage between the protective ground terminal and the reference ground terminal as a voltage signal; a buffer, which is electrically connected to the voltage dividing circuit, and the buffer receives the voltage signal; an amplifier, The amplifier is electrically connected to the buffer, the amplifier receives the voltage signal output after buffering by the buffer; and a filter is electrically connected to the amplifier, and the filter filters the voltage signal amplified by the amplifier to This detection voltage is output. The on-board charging device according to claim 4, wherein the voltage dividing circuit includes: a first resistor, one end of which is electrically connected to the protective ground terminal of the on-board charging device; a second resistor, connected to the first A resistor is connected in series, one end of the second resistor is electrically connected to the other end of the first resistor, and the other end of the second resistor is electrically connected to the reference ground terminal of the AC-to-DC converter; and a filter A circuit in parallel with the second resistor. The on-board charging device according to claim 4, wherein the buffer is a voltage follower. The on-board charging device according to claim 4, wherein the amplifier is a differential amplifier. The on-board charging device according to claim 4, wherein the filter is a low-pass filter. The on-board charging device according to claim 1, further comprising: an isolation stage electrically connected to the AC-to-DC converter; a DC-to-DC converter electrically connected to the isolation stage; and an output filter, electrically The DC-to-DC converter is connected, wherein the DC voltage output by the AC-to-DC converter is converted by the isolation stage and the DC-to-DC converter and then filtered by the output filter to provide a vehicle charging voltage to a vehicle. A method for operating a vehicle-mounted charging device. The vehicle-mounted charging device includes an AC connector and an AC-to-DC converter. The operation method includes: when the AC connector is connected to an electric vehicle charging device, The protective ground terminal is electrically connected to a protective ground terminal of the vehicle charging device. Based on the voltage difference between a protective ground terminal of the vehicle charging device and a reference ground terminal of the AC-to-DC converter, a detection voltage is output. And determining whether the protective ground terminal of the electric vehicle charging device is abnormal according to the detection voltage. The operating method according to claim 10, wherein the step of determining whether the protective ground terminal of the electric vehicle charging device is abnormal or not includes: determining the voltage of the electric vehicle charging device when the detected voltage is lower than a preset threshold voltage; The protective ground terminal is abnormal. The operating method according to claim 10, wherein the step of determining whether the protective ground terminal of the electric vehicle charging device is abnormal or not includes: determining the voltage of the electric vehicle charging device when the detected voltage is higher than the preset threshold voltage; The protective ground terminal is normal. The operation method according to claim 10, further comprising: when the AC connector is connected to the electric vehicle charging device, determining whether an AC voltage provided by the electric vehicle charging device is higher than a predetermined voltage; and when the electric vehicle When the AC voltage provided by the charging device is higher than the predetermined voltage, it is determined whether the AC voltage falls within a first voltage interval. The operating method according to claim 13, wherein the step of determining whether the protective ground terminal of the electric vehicle charging device is abnormal according to the detected voltage includes: when the AC voltage falls within the first voltage interval, determining the Whether the detection voltage is lower than a first preset threshold voltage; when the detection voltage is lower than the first preset threshold voltage, judging whether the period during which the detection voltage continues to fall below the first preset threshold voltage exceeds a A first predetermined time; and after the period when the detection voltage continues to be lower than the first preset threshold voltage has exceeded the first predetermined time, it is determined that the protective ground terminal of the electric vehicle charging device is abnormal. The operating method according to claim 13, wherein the step of determining whether the protective ground terminal of the electric vehicle charging device is abnormal according to the detected voltage includes: when the AC voltage does not fall within the first voltage range but falls In a second voltage interval, determine whether the detection voltage is lower than a second preset threshold voltage; when the detection voltage is lower than the second preset threshold voltage, determine that the detection voltage is continuously lower than the first preset threshold voltage Whether the period of the two preset threshold voltages exceeds a second predetermined time; and after the period in which the detection voltage continues to be lower than the second preset threshold voltage has exceeded the second predetermined time, determine whether the electric vehicle charging device has The protective ground terminal is abnormal.