CN215067207U

CN215067207U - Fault detection device in charging equipment and charging equipment

Info

Publication number: CN215067207U
Application number: CN202121267239.7U
Authority: CN
Inventors: 刘伟; 苑传友; 沈岩
Original assignee: Webasto Shanghai Ltd
Current assignee: Webasto Shanghai Ltd
Priority date: 2021-06-08
Filing date: 2021-06-08
Publication date: 2021-12-07
Anticipated expiration: 2031-06-08

Abstract

The utility model provides a fault detection device in battery charging outfit, battery charging outfit include the coupling first relay between first electric input end and first electric output end and the coupling second relay between second electric input end and second electric output end, include: a first detection module coupled between the first electrical input and the second electrical output and configured to output a first detection signal upon initiating fault detection; a second detection module coupled between the second electrical input and the first electrical output and configured to output a second detection signal upon turn-on fault detection; and the control module is configured to control the first detection module and the second detection module to start or stop fault detection, and judge whether the first relay and the second relay have faults and whether the first electrical output end and the second electrical output end are short-circuited according to the first detection signal and the second detection signal. The utility model discloses can detect battery charging outfit's major loop relay trouble and output short circuit.

Description

Fault detection device in charging equipment and charging equipment

Technical Field

The utility model relates to an electric vehicle technical field that charges. And more particularly, to a fault detection device in a charging apparatus, a charging apparatus including the fault detection device, and a fault detection method of the charging apparatus.

Background

In recent years, with the rapid development of the new energy automobile industry, the demand for charging piles is increasing day by day. How to reduce the cost and improve the reliability and the safety becomes an urgent need for research and development of the charging pile and enhancement of enterprise competitiveness of manufacturers.

As shown in fig. 1, in the ac charging pile, high-voltage relays (or called contactors) such as K1 and K2 are required to be disposed on the live line (L line) and the neutral line (N line) between the power supply equipment 1 and the power supply interface 2. The power supply control device 3 controls the high-voltage relays K1, K2 to be closed and opened, thereby switching on and off the high-voltage large-current main circuit. The high-voltage relays K1 and K2 are bridges between the low-voltage control circuit and the high-voltage circuit. Their operating conditions play a crucial role in the normal operation of the charging pile. Therefore, it is necessary to detect the operating state thereof. For the electromagnetic relay, because it is a mechanical switch type power element, under the working condition of high voltage and large current, the relay is easy to cause the relay fault including the contact adhesion or the contact blocking when the relay is overloaded or switched with load. The contact adhesion means that the relay contact is in a closed state and cannot be normally disconnected; the dead contact is that the relay contact is in an open state and can not be normally closed. This requires the contact state of the relay to be detected before the start of each charge and after the end of the charge.

Fig. 2 illustrates a conventional relay fault detection method. In fig. 2, relay K1 in hot has two sets of stationary contacts: a detection return contact AB and a main return contact CD. The detection loop contact AB is used for controlling the on-off of the detection loop 4, and the main loop contact CD is used for controlling the on-off of the live wire. When the coil EF is energized, the moving contact of the relay K1 should be connected to the main circuit contact CD and disconnected from the detection circuit contact AB, and the single chip microcomputer should detect a high level at the detection point T because the detection circuit 4 is not connected. If the singlechip detects a low level at this time, the singlechip indicates that the movable contact is not connected with the main loop contact CD, cannot be normally closed with the main loop contact CD and is adhered with the detection loop contact AB (which is equivalent to the situation that the contacts are stuck). When the coil EF is powered off, the movable contact of the relay K1 is connected with the detection loop contact AB and disconnected with the main loop contact CD, and the singlechip detects a low level at a detection point T because the detection loop is connected. If the singlechip detects a high level at the moment, the movable contact is adhered to the main loop contact CD and cannot be normally disconnected (which is equivalent to the condition that the contacts are adhered).

However, the conventional relay fault detection method requires a customized relay with a detection circuit contact, which is expensive. In addition, the added detection circuit contacts need to additionally design an insulation circuit, otherwise, high voltage can enter a low-voltage detection circuit, and the damage risk of the control circuit is increased.

SUMMERY OF THE UTILITY MODEL

Need the customization to have the relay that detects the return circuit contact when solving among the prior art detection relay trouble, the technical problem that the cost is comparatively high and the circuit is complicated, the utility model provides a simple structure, low cost's fault detection device.

To this end, according to an aspect of the present invention, there is provided a fault detection device in a charging apparatus, the charging apparatus including a first relay coupled between a first electrical input and a first electrical output and a second relay coupled between a second electrical input and a second electrical output, the fault detection device including: a first detection module coupled between the first electrical input and the second electrical output and configured to output a first detection signal upon fault detection; a second detection module coupled between the second electrical input and the first electrical output and configured to output a second detection signal upon fault detection; and the control module is configured to receive the first detection signal and the second detection signal and judge whether the first relay and the second relay are in fault and whether the first electrical output end and the second electrical output end are in short circuit according to the first detection signal and the second detection signal.

The utility model provides a fault detection device can detect whether the main circuit relay of battery charging outfit breaks down, can detect whether the output of battery charging outfit short circuit again. Meanwhile, no customized element is needed in the fault detection device, and the detection loop and the main loop are well insulated, so that the fault detection device is simple in structure, low in price and high in cost benefit.

In one embodiment, the fault detection apparatus further comprises a first switch module and a second switch module, the control module is further configured to control the first switch module and the second switch module according to a predetermined timing, and the first switch module is configured to cause the first detection module to turn on or off fault detection via control of the control module; the second switching module is configured to cause the second detection module to turn on or off fault detection via control of the control module.

In one embodiment, the first switch module includes: a third relay coupled in series with the first detection module; and a first semiconductor element, wherein a first pole of the first semiconductor element is coupled to the coil of the third relay, a control pole of the first semiconductor element is coupled to the control module, and a second pole of the first semiconductor element is coupled to the ground potential, wherein the first semiconductor element responds to the control of the control module to drive the contact of the third relay to be closed or opened, so that the first detection module starts or stops the fault detection.

In one embodiment, the second switch module includes: a fourth relay coupled in series with the second detection module; and a second semiconductor element, a first pole of which is coupled to the coil of the fourth relay, a control pole of which is coupled to the control module, and a second pole of which is coupled to the ground potential, wherein the second semiconductor element drives the contact of the fourth relay to be closed or opened in response to the control of the control module, thereby enabling the second detection module to turn on or off the fault detection.

In one embodiment, the first detection module comprises: and the light receiving element outputs a first detection signal, wherein when current flows through the light emitting element, the first detection signal is at a low level, otherwise, the first detection signal is at a high level.

In one embodiment, the second detection module comprises: and a second optical coupler, wherein a light emitting element of the second optical coupler is coupled between a second electrical input end and a first electrical output end, and a light receiving element outputs a first detection signal, wherein when current flows through the light emitting element, the second detection signal is at a low level, otherwise, the second detection signal is at a high level.

In one embodiment, the fault detection device further comprises: a first current limiting module coupled in series with the first detection module and configured to reduce current flowing through the first detection module; and a second current limiting module coupled in series with the second detection module and configured to reduce current flowing through the second detection module.

In one embodiment, the first current limiting module includes at least a first resistor and the second current limiting module includes at least a second resistor.

In one embodiment, alternating current is provided between the first electrical input and the second electrical input, and the fault detection device further comprises: a first rectification module coupled in series with the first detection module and configured to rectify the alternating current when the first electrical input is in communication with the second electrical input via the second relay; and a second rectification module coupled in series with the second detection module and configured to rectify the alternating current when the first electrical input is in communication with the second electrical input via the first relay.

In one embodiment, the first rectifier module includes a first diode and the second rectifier module includes a second diode.

In one embodiment, determining whether the first relay and the second relay are malfunctioning and whether there is a short circuit between the first electrical output and the second electrical output based on the first detection signal and the second detection signal further comprises: judging whether the first detection signal and the second detection signal accord with a group of preset signals or not; if so, it is determined that the first relay and the second relay are not malfunctioning and that there is no short circuit between the first electrical output and the second electrical output.

In one embodiment, the control module is further configured to: and controlling the first relay and the second relay to be closed or opened according to a preset time sequence.

According to another aspect of the present invention, there is provided a charging apparatus including the fault detection device according to any one of the above embodiments.

According to the utility model discloses an on the other hand provides a battery charging outfit's fault detection method, and this fault detection method is based on any fault detection device in the above-mentioned embodiment, and this fault detection method includes: receiving a charge ready signal instructing a charging device to output power; responding to a charging ready signal, and starting fault detection of the first detection module and the second detection module while controlling the first relay and the second relay to be kept disconnected; receiving a first detection signal and a second detection signal from a first detection module and a second detection module, respectively; and judging whether the first relay and the second relay are disconnected and whether the first electric output end and the second electric output end are short-circuited according to the first detection signal and the second detection signal.

The utility model provides a fault detection method has realized the multiple fault detection before battery charging outfit charges for the load. By the detection method, whether the main loop relay of the charging equipment is adhered or not can be detected, and whether the output end of the charging equipment is short-circuited or not can be detected, so that the risk of the fault of the charging equipment is reduced to a great extent.

In one embodiment, the fault detection method further comprises: if the first relay and the second relay are both disconnected and the first electrical output end and the second electrical output end are not short-circuited, controlling the first relay and the second relay to be closed, and detecting whether the first relay and the second relay are closed or not after a first time interval; otherwise, a fault signal is sent.

In one embodiment, detecting whether the first relay and the second relay are closed after the first time interval further comprises: receiving a first detection signal and a second detection signal from a first detection module and a second detection module, respectively; judging whether the first relay and the second relay are closed or not according to the first detection signal and the second detection signal; and if the first relay and the second relay are both closed, the fault detection of the first detection module and the second detection module is closed, otherwise, a fault signal is sent.

According to the utility model discloses an on the other hand provides a battery charging outfit's fault detection method, and this fault detection method is based on any fault detection device in the above-mentioned embodiment, and this fault detection method includes: receiving a charge end signal instructing the charging device to stop outputting electric power; controlling the first relay and the second relay to be disconnected in response to the charging end signal; after a second time interval, starting fault detection of the first detection module and the second detection module; receiving a first detection signal and a second detection signal from a first detection module and a second detection module, respectively; and judging whether the first relay and the second relay are disconnected and whether the first electric output end and the second electric output end are short-circuited according to the first detection signal and the second detection signal.

The utility model provides a fault detection method has realized the multiple fault detection after battery charging outfit finishes charging. By the detection method, whether the main loop relay of the charging equipment is adhered or not can be detected, and whether the output end of the charging equipment is short-circuited or not can be detected, so that the risk of the fault of the charging equipment is reduced to a great extent.

In one embodiment, the fault detection method further comprises: if the first relay and the second relay are both disconnected and the first electric output end and the second electric output end are not short-circuited, the fault detection of the first detection module and the second detection module is closed, and if not, a fault signal is sent out.

Drawings

Embodiments of the present invention are shown and described below with reference to the drawings. It is to be noted that these drawings are for the purpose of illustrating the general principles of the invention and are thus only illustrative of the aspects which are essential to an understanding of the general principles. The figures are not drawn to scale. In the drawings, like reference numerals designate similar features.

Fig. 1 shows a schematic view of an ac charging post;

FIG. 2 illustrates a conventional relay fault detection method;

fig. 3 shows a schematic architecture of a fault detection device according to an embodiment of the present invention;

fig. 4 shows a schematic view of a fault detection arrangement according to an embodiment of the invention;

FIG. 5 shows a flow chart of a power-up procedure detection method according to the fault detection arrangement of FIG. 4;

FIG. 6 shows a flow chart of a power down process detection method according to the fault detection arrangement of FIG. 4; and

fig. 7 shows a detection timing diagram of the fault detection method of fig. 5 and 6.

Detailed Description

In the following detailed description of the preferred embodiments, reference is made to the accompanying drawings which form a part hereof. The accompanying drawings illustrate, by way of example, specific embodiments in which the invention may be practiced. The illustrated embodiments are not intended to be exhaustive of all embodiments according to the invention. It is to be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope of the present invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined by the appended claims.

Before describing embodiments of the present invention, some terms referred to in the present invention will be explained first to better understand the present invention.

In the present invention, a transistor may refer to a transistor of any structure, such as a Field Effect Transistor (FET), a Bipolar Junction Transistor (BJT), or a thyristor. When the transistor is a field effect transistor, the control electrode of the transistor refers to a grid electrode of the field effect transistor, the first electrode can be a drain electrode or a source electrode of the field effect transistor, and the corresponding second electrode can be a source electrode or a drain electrode of the field effect transistor; when the transistor is a bipolar transistor, the control electrode of the transistor refers to the base electrode of the bipolar transistor, the first electrode can be the collector electrode or the emitter electrode of the bipolar transistor, and the corresponding second electrode can be the emitter electrode or the collector electrode of the bipolar transistor; when the transistor is a thyristor, the control electrode of the transistor is the control electrode G of the thyristor, the first electrode is an anode, and the second electrode is a cathode.

As used herein, the terms "connected" or "coupled" and the like are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The terms "a," "an," "a," or "the" and similar terms do not denote a limitation of quantity, but rather denote the presence of at least one.

As used herein, the terms "comprising," "including," and similar terms are open-ended terms, i.e., "including/including but not limited to," meaning that additional items may be included as well. The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment," and the like. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

The utility model aims at providing a fault detection device and fault detection method. The fault detection device and the fault detection method can detect whether the main loop relay of the charging equipment has faults or not, and can also detect whether the output end of the charging equipment is short-circuited or not. Meanwhile, no customized element is needed in the fault detection device, and the detection loop and the main loop are well insulated, so that the fault detection device is simple in structure, low in price and high in cost benefit.

Fig. 3 shows an architecture diagram of a fault detection device according to an embodiment of the present invention.

As shown in fig. 3, the charging apparatus includes a first relay 10 and a second relay 11. The first relay 10 is coupled between the first electrical input 20 and the first electrical output 21, and the second relay 11 is coupled between the second electrical input 22 and the second electrical output 23. The first electrical input 20 and the second electrical input 22 are coupled to a power supply device for inputting direct current or alternating current, and the first electrical output 21 and the second electrical output 23 are coupled to a power supply interface. The fault detection means comprises a first detection module 30, a second detection module 31 and a control module 32. The first detection module 30 is coupled between the first electrical input 20 and the second electrical output 23 to form a first detection loop for outputting a first detection signal when performing fault detection. The second detection module 31 is coupled between the second electrical input 22 and the first electrical output 21 to form a second detection loop for outputting a second detection signal when performing fault detection. The control module 32 receives the first detection signal and the second detection signal from the first detection module 30 and the second detection module 31, respectively, and determines whether the first relay 10 and the second relay 11 are failed and whether a short circuit occurs between the first electrical output terminal 21 and the second electrical output terminal 23 according to the first detection signal and the second detection signal.

In particular, with reference to fig. 3, the state (closed or open) of the first relay 10 and the second relay 11 and the short circuit condition between the first electrical output 21 and the second electrical output 23 may affect the current loop formed from the first electrical input 20 to the second electrical input 22. Thus, when the first relay 10, the second relay 11 are in different states and the short circuit condition between the first electrical output 21 and the second electrical output 23 is different, the situation of forming a current loop from the first electrical input 20 to the second electrical input 22 is also different. Accordingly, the signals output by the first detection module 30 and the second detection module 31 are also different. Therefore, it is possible to determine whether the first relay 10 and the second relay 11 are malfunctioning (i.e., whether they are operating normally or in an expected state) and a short-circuit condition between the first electrical output 21 and the second electrical output 23, based on the first detection signal and the second detection signal. Each detection module may include an element for detecting the on/off of the current loop, such as a hall sensor, an optical coupler, and the like.

In some embodiments, the control module 32 determines whether the first detection signal and the second detection signal correspond to a set of predetermined signals. If so, it is determined that the first relay 10 and the second relay 11 are not malfunctioning (i.e., operating normally or in an expected state) and that there is no short circuit between the first electrical output 21 and the second electrical output 23. The preset signal is a signal that the first and

second detection modules

30 and 31 should output in case the first and

second relays

10 and 11 are in the expected state and there is no short circuit between the first and second

electrical outputs

21 and 23. When the fault detection is performed, if the first detection signal and the second detection signal are consistent with the set of preset signals, it indicates that the first relay 10 and the second relay 11 are normally closed or opened and the first electrical output end and the second electrical output end are not short-circuited. In some embodiments, the control module 32 controls the first relay 10 and the second relay 11 to close or open according to a predetermined timing to determine the expected states of the first relay 10 and the second relay 11.

In some embodiments, the fault detection device further comprises a first switch module and a second switch module (not shown in fig. 3). The control module 32 controls the first and second switch modules according to a predetermined timing. The first switch module is coupled in series with the first detection module 30 and is controlled by the control module 32 to switch the first detection loop on or off, enabling the first detection module 30 to turn on or off fault detection. The second switch module is coupled in series with the second detection module 31, and is controlled by the control module 32 to switch on or off the second detection loop, so that the second detection module 31 turns on or off the fault detection. Each switching module may include any form of switching element, such as a relay.

In some embodiments, the fault detection device further includes a first current limiting module and a second current limiting module (not shown in fig. 3). The first current limiting module is coupled in series with the first detection module 30 for reducing the current flowing through the first detection module 30. The second current limiting module is coupled in series with the second detection module 31 for reducing the current flowing through the second detection module 31. Each current limiting module may include one or more current limiting elements, such as one or more resistors connected in series.

In some embodiments, an alternating current is provided between the first electrical input 20 and the second electrical input 22. The fault detection device further comprises a first rectifier module and a second rectifier module (not shown in fig. 3). The first rectifying module is coupled in series with the first detection module 30 and rectifies the alternating current when the first electrical input 20 is in communication with the second electrical input 22 via the second relay 11. The second rectifying module is coupled in series with the second detection module 31 and rectifies the alternating current when the first electrical input 20 is in communication with the second electrical input 22 via the first relay 10. Each of the rectification modules may be a half-wave rectification module or a full-wave rectification module.

Fig. 4 shows a schematic view of a fault detection device according to an embodiment of the present invention.

In the embodiment of fig. 4, the charging device is an ac charging pile, and a live line (L line) and a neutral line (N line) are provided between the power supply device and the power supply interface. The first electrical input 20 and the first electrical output 21 are respectively a live input L _ IN and a live output L _ OUT, and the second electrical input 22 and the second electrical output 23 are respectively a neutral input N _ IN and a neutral output N _ OUT. 50Hz alternating current is input between the live wire input end L _ IN and the zero wire input end N _ IN. A first relay K1 is provided between the live input terminal L _ IN and the live output terminal L _ OUT for controlling the power connection therebetween. A second relay K2 is provided between the neutral input terminal N _ IN and the neutral output terminal N _ OUT for controlling the power connection therebetween. The fault detection device includes a first detection module 30, a first rectification module 33, a first current limiting module 35, a first switching module 37, a second detection module 31, a second rectification module 34, a second current limiting module 36, a second switching module 38, and a control module (not shown in fig. 4). In the present embodiment, the control module is implemented as a micro processing unit (MCU).

The first rectifying module 33 comprises a first diode D1, the anode of which is connected to the hot input terminal L _ IN. The first detection module 30 includes a first optocoupler U1 having an anode of a light emitting element (i.e., a light emitting diode) connected to a cathode of a first diode D1, a first pole of a light receiving element (i.e., a phototransistor) coupled to a power supply via a third resistor R3, and a second pole coupled to ground potential. A first pole of the light receiving element of the first optocoupler U1 outputs a first detection signal and provides the first detection signal to the MCU coupled to the first pole. The first current limiting module 35 includes a first resistor R1 connected to a cathode of the light emitting diode of the first optocoupler U1. The first switching module 37 includes a third relay K3 and a first semiconductor element Q1. In the present embodiment, the first semiconductor element Q1 is implemented as a transistor. The third relay K3 has a stationary contact connected to a first resistor R1 and the neutral output terminal N _ OUT, and has a coil connected at one end to the power supply and at the other end to the first pole of a first transistor Q1. The third diode D3 is connected in reverse between the two ends of the coil. A first transistor Q1 has its control electrode coupled to the MCU and its second electrode coupled to ground. The MCU transmits a control signal to the first transistor Q1, that is, outputs a high level to turn on the first transistor Q1 or outputs a low level to turn off the first transistor Q1. The first transistor Q1 drives the contact of the third relay K3 to close or open in response to the control of the MCU, thereby enabling the first detection module 30 to turn on or off fault detection. In the present embodiment, when the first transistor Q1 is turned on, a current change is generated in the coil of the third relay K3 to generate a magnetic field, and the drive contact is closed. At this time, the detection circuits D1-U1-R1-K3 are connected, so that the first detection module 30 starts fault detection. When the first transistor Q1 is turned off, no current is generated in the coil of the third relay K3, and the contact is opened. At this time, the detection loop D1-U1-R1-K3 is open, causing the first detection module 30 to shut down fault detection. IN addition, when the live input terminal L _ IN forms a loop with the neutral input terminal N _ IN via the second relay K2, the first diode D1 rectifies the alternating current IN the positive half cycle of the alternating current, i.e., the L _ IN potential is higher than the N _ IN potential, and the first diode D1 increases the withstand voltage of the entire loop IN the negative half cycle of the alternating current, i.e., the L _ IN potential is lower than the N _ IN potential.

The second rectifying module 34 includes a second diode D2 having an anode connected to the hot output terminal L _ OUT. The second detection module 31 includes a second optocoupler U2, in which the anode of the light emitting element (i.e. light emitting diode) is connected to the cathode of the second diode D2, the first pole of the light receiving element (i.e. phototransistor) is coupled to the power supply via a fourth resistor R4, and the second pole is coupled to ground potential. The first pole of the light receiving element of the second optocoupler U2 outputs a second detection signal. The MCU is coupled to the first pole and receives the second detection signal. The second current limiting module 36 includes a second resistor R2 connected to a cathode of the light emitting diode of the second optocoupler U2. The second switching module 38 includes a fourth relay K4 and a second semiconductor element Q2. In the present embodiment, the second semiconductor element Q2 is implemented as a transistor. The stationary contact of the fourth relay K4 is connected to the second resistor R2 and the neutral input terminal N _ IN, and one end of the coil thereof is connected to the power supply and the other end thereof is connected to the first pole of the second transistor Q2. The fourth diode D4 is connected in reverse between the two ends of the coil. The control electrode of the second transistor Q2 is coupled to the MCU and the second electrode is coupled to ground. The MCU sends a control signal to the second transistor Q2, that is, outputs a high level to turn on the second transistor Q2 or outputs a low level to turn off the second transistor Q2. The second transistor Q2 drives the contact of the fourth relay K4 to close or open in response to the control of the MCU, thereby enabling the second detection module 31 to turn on or off fault detection. In this embodiment, when the second transistor Q2 is turned on, a current change is generated in the coil of the fourth relay K4 to generate a magnetic field, which drives the contacts to close. At this time, the detection circuits D2-U2-R2-K4 are communicated, so that the second detection module 31 starts fault detection. When the second transistor Q2 is turned off, no current is generated in the coil of the fourth relay K4, and the contact is opened. At this time, the detection loop D2-U2-R2-K4 is opened, causing the second detection module 31 to shut down fault detection. When the live input end L _ IN forms a loop with the neutral input end N _ IN through the first relay K1, the second diode D2 rectifies the alternating current IN the positive half cycle of the alternating current, i.e., when the L _ IN potential is higher than the N _ IN potential, and the second diode D2 increases the withstand voltage of the entire loop IN the negative half cycle of the alternating current, i.e., when the L _ IN potential is lower than the N _ IN potential.

It should be noted that the diodes, optocouplers, transistors and resistors in this embodiment are conventional elements, rather than any form or kind of customized element. In particular, the third relay K3 and the fourth relay K4 are two independent conventional relays. In addition, in the present embodiment, the detection circuit and the main circuit have good insulation. Therefore, the circuit structure of the embodiment does not need any customized element, does not need to design other isolation circuits, and has simple structure, low cost and higher safety.

The different states of the first relay K1 and the second relay K2 and the short-circuit condition of the live output end L _ OUT and the neutral output end N _ OUT are listed below to specifically describe the signals output at OUT1 and OUT2 by the first optical coupler U1 and the second optical coupler U2 during fault detection. The MCU controls the first transistor Q1 and the second transistor Q2 to drive the contacts of the third relay K3 and the fourth relay K4 to be closed, and the first detection module 30 and the second detection module 31 start fault detection.

1) The first relay K1 and the second relay K2 are both in an open state, and no short circuit exists between the live wire output end L _ OUT and the zero wire output end N _ OUT.

A loop cannot be formed between the live line input end L _ IN and the zero line input end N _ IN, and both OUT1 and OUT2 output high levels.

2) The first relay K1 and the second relay K2 are both in an open state, and the live wire output end L _ OUT and the zero wire output end N _ OUT are in short circuit.

When the potential of L _ IN is higher than that of N _ IN, current flows from L _ IN through D1-U1-R1-K3-N _ OUT-L _ OUT-D2-U2-R2-K4 to N _ IN to form a loop, so that OUT1 and OUT2 both output low level. When the potential of N _ IN is higher than L _ IN, the loop is not closed because the first diode D1 and the second diode D2 are turned off IN reverse. Therefore, under the action of 50Hz alternating current, OUT1 and OUT2 output 50Hz in-phase square waves.

3) The first relay K1 is in an open state, the second relay K2 is in a closed state, and no short circuit exists between the live wire output end L _ OUT and the zero wire output end N _ OUT.

When the L _ IN potential is higher than N _ IN, current flows from L _ IN through D1-U1-R1-K3-K2 to N _ IN forming a loop, causing OUT1 to output a low level and OUT2 to output a high level. When the potential of N _ IN is higher than L _ IN, the loop is not closed because the first diode D1 is turned off IN the reverse direction. Thus, under the action of 50Hz AC, OUT1 outputs a 50Hz in-phase square wave, while OUT2 outputs a sustained high level.

4) The first relay K1 is in an open state, the second relay K2 is in a closed state, and the live output end L _ OUT and the zero output end N _ OUT are in short circuit.

5) The first relay K1 is in a closed state, the second relay K2 is in an open state, and no short circuit exists between the live wire output end L _ OUT and the zero wire output end N _ OUT.

When the L _ IN potential is higher than N _ IN, current flows from L _ IN through K1-D2-U2-R2-K4 to N _ IN forming a loop, causing OUT2 to output a low level and OUT1 to output a high level. When the potential of N _ IN is higher than L _ IN, the loop is not turned on because the second diode D2 is turned off IN the reverse direction. Thus, under the action of 50Hz AC, OUT2 outputs a 50Hz in-phase square wave, while OUT1 outputs a sustained high level.

6) The first relay K1 is in a closed state, the second relay K2 is in an open state, and the live output end L _ OUT and the zero output end N _ OUT are in a short circuit.

7) The first relay K1 and the second relay K2 are both in a closed state, and no short circuit exists between the live wire output end L _ OUT and the zero wire output end N _ OUT.

When the level of L _ IN is higher than that of N _ IN, a loop is formed from L _ IN to N _ IN through D1-U1-R1-K3-K2, so that OUT1 outputs low level. The other current is looped from L _ IN through K1-D2-U2-R2-K4 to N _ IN, so that OUT2 outputs low level. When the potential of N _ IN is higher than that of L _ IN, the loop is not closed because the first diode D1 and the second diode D2 are both turned off IN the reverse direction. Therefore, under the action of 50Hz alternating current, both OUT1 and OUT2 output 50Hz in-phase square waves.

8) The first relay K1 and the second relay K2 are both in a closed state, and the live wire output end L _ OUT and the zero wire output end N _ OUT are in short circuit.

IN this case, L _ IN-K1-L _ OUT-N _ OUT-K2-N _ IN forms a short circuit that immediately triggers short circuit protection, e.g., the charging device automatically opens the air switch.

In the present embodiment, in addition to controlling the third relay K3 and the fourth relay K4 to turn on the fault detection and to judge the fault of the first relay K1 and the second relay K2 and the short-circuit condition of the output terminals, the same MCU also controls the first relay K1 and the second relay K2 to be closed and opened according to a preset timing, thereby determining the expected states of the first relay K1 and the second relay K2. In this way, in the process of fault detection, whether the first relay K1 and the second relay K2 have faults or not and whether the live wire output end L _ OUT and the zero wire output end N _ OUT are short-circuited or not can be judged according to the matching relation between the signals output by the OUT1 and the OUT2 and the relay states and the output end short-circuit conditions. Similarly to the control of the third relay K3 and the fourth relay K4, the MCU also controls the first relay K1 and the second relay K2 by controlling driving transistors (not shown in fig. 4). In other embodiments, the first relay K1 and the second relay K2 may be controlled by other controllers as long as the MCU can know the expected states of the first relay K1 and the second relay K2.

The process of fault detection by the fault detection apparatus of fig. 4 is explained next with reference to fig. 5-7. Fig. 5 and 6 show flowcharts of a power-up process detection method and a power-down process detection method of the fault detection apparatus according to fig. 4, respectively, and fig. 7 shows detection timing charts of the fault detection methods of fig. 5 and 6, in which when a control signal of a relay is at a high level, it indicates that the corresponding relay is controlled to be closed, and when the control signal of the relay is at a low level, it indicates that the corresponding relay is controlled to be open.

The charging device first performs the power-up process detection method 500 by its MCU before outputting power to the onboard charger. In step 501, a charge ready signal is received, the charge ready signal instructing a charging device to output power. And after the vehicle-mounted charger receives the indication signal from the whole vehicle, sending a charging ready signal to the charging equipment. In step 502, in response to the charge ready signal, fault detection of the first and

second detection modules

30 and 31 is turned on while the first and second relays K1 and K2 are controlled to remain open. After the previous charging is finished, the first relay K1 and the second relay K2 are controlled to be disconnected and continuously kept until the next charging is started. Therefore, in the case where the first relay K1 and the second relay K2 are not malfunctioning (i.e., are not stuck), the first relay K1 and the second relay K2 should be in the open state at this time. In the present embodiment, the fault detection is turned on by controlling the third relay K3 and the fourth relay K4 to close. Referring to fig. 4 and 7, at time t1, a high level is simultaneously supplied to the gates of the driving transistors Q1 and Q2 of the third relay K3 and the fourth relay K4, so that the two detection circuits are communicated.

In step 503, a first detection signal and a second detection signal are received from the first detection module 30 and the second detection module 31, respectively. The current loop and the detection signals output by the first and

second detection modules

30 and 31 are also different according to the states of the first and second relays K1 and K2 and the short-circuit condition of the output terminals. Next, in step 504, it is determined whether the first relay K1 and the second relay K2 are open and whether there is a short circuit between the first electrical output terminal and the second electrical output terminal, based on the first detection signal and the second detection signal. If both relays K1, K2 are open (i.e., not stuck) and the output is not shorted, go to step 505, otherwise go to step 506. Specifically, referring to fig. 4, if both OUT1 and OUT2 output a high level, it indicates that both the first relay K1 and the second relay K2 are in an open state and there is no short circuit between the live output terminal L _ OUT and the neutral output terminal N _ OUT. Therefore, when both the first detection signal and the second detection signal are high level, it is determined that both the relays K1, K2 are open and the output terminal is not short-circuited.

In step 505, the first relay K1 and the second relay K2 are controlled to be closed. Specifically, at time t2 in fig. 7, a high level is simultaneously supplied to the control electrodes of the drive transistors of the first relay K1 and the second relay K2. Next, it is necessary to detect whether the first relay K1 and the second relay K2 are normally closed. Since it has been determined in step 504 that there is no short circuit between the first electrical output and the second electrical output, there is no need to determine a short circuit condition at the output. In order to ensure that the first relay K1 and the second relay K2 are in a stable state during the detection, and to avoid detection errors, it is necessary to detect whether they are closed after the first time interval. The first time interval may be arbitrarily set as long as the first relay K1 and the second relay K2 are ensured to be in a stable state.

In step 506, a fault signal is sent, terminating power up. The fault signal may be any type or form of signal such as an indicator light, an alarm on a display screen, an audible signal light, etc. to alert an operator to service. And after the overhaul is finished, restarting the power-on detection. Although not shown in fig. 5, a low level is also supplied to the control electrodes of the driving transistors of the first to fourth relays K1-K4 to disconnect all power connections while transmitting the fault signal.

In step 507, a first detection signal and a second detection signal are received from the first detection module 30 and the second detection module 31, respectively. Next, in step 508, it is determined whether the first relay K1 and the second relay K2 are closed according to the first detection signal and the second detection signal. If both relays are closed (i.e., not stuck), go to step 509, otherwise go to step 506. Specifically, referring to fig. 4, if both OUT1 and OUT2 output an in-phase square wave, it indicates that both the first relay K1 and the second relay K2 are in a closed state. Therefore, when both the first detection signal and the second detection signal are in-phase square waves, it is determined that both the relays K1, K2 are closed.

In step 509, the fault detection of the first and second detection modules is turned off. Specifically, at time t3 in fig. 7, a low level is simultaneously supplied to the gates of the drive transistors Q1 and Q2 of the third relay K3 and the fourth relay K4, and the contacts of the drive transistors K3 and the fourth relay K4 are opened, thereby opening the detection circuit. The time interval (e.g., 3 seconds) between the time t3 and the time t2 can be set according to actual needs. By disconnecting the detection loop after the detection is completed, the power consumption of the circuit can be reduced, and the safety can be further improved. After the power-on detection is successful, the charging equipment can output electric power to the vehicle-mounted charger.

Once charging is complete, the MCU of the charging device executes the power down detection method 600. In step 601, a charge end signal is received, which instructs the charging device to stop outputting power. Next, step 602 includes controlling the first relay K1 and the second relay K2 to open in response to the end-of-charge signal. Specifically, at time t4 in fig. 7, the low level is simultaneously supplied to the drive transistors of the first relay K1 and the second relay K2.

The method continues to step 603 where fault detection of the first detection module 30 and the second detection module 31 is enabled after a second time interval. The second time interval is used for ensuring that the first relay K1 and the second relay K2 are in a stable state during detection, and detection errors are avoided. The second time interval may be set according to actual needs, such as 3 seconds. Specifically, at time t5 in fig. 7, the high level is simultaneously supplied to the gates of the drive transistors Q1 and Q2 of the third relay K3 and the fourth relay K4, and the two detection circuits are made to communicate. In the case where the first relay K1 and the second relay K2 are not malfunctioning (i.e., are not stuck), the first relay K1 and the second relay K2 should be in the open state at this time.

In step 604, a first detection signal and a second detection signal are received from the first detection module 30 and the second detection module 31, respectively. Next, in step 605, it is determined whether the first relay K1 and the second relay K2 are open and whether the first electrical output terminal and the second electrical output terminal are short-circuited according to the first detection signal and the second detection signal. If both relays K1, K2 are open (i.e., not stuck) and the output is not shorted, go to step 606, otherwise go to step 607. Specifically, referring to fig. 4, if both OUT1 and OUT2 output a high level, it indicates that both the first relay K1 and the second relay K2 are in an open state and there is no short circuit between the live output terminal L _ OUT and the neutral output terminal N _ OUT. Therefore, when both the first detection signal and the second detection signal are high level, it is determined that both the relays K1, K2 are open and the output terminal is not short-circuited.

In step 606, the fault detection of the first detection module 30 and the second detection module 31 is turned off. Specifically, at time t6 in fig. 7, a low level is simultaneously supplied to the control electrodes of the driving transistors Q1 and Q2 of the third relay K3 and the fourth relay K4, thereby opening the detection circuit.

In step 607, a fault signal is transmitted. The fault signal may be any type or form of signal such as an indicator light, an alarm on a display screen, a sound signal light to alert an operator to service. Although not shown in fig. 6, a low level is also supplied to the control electrodes of the driving transistors of the first to fourth relays K1-K4 to disconnect all power connections while transmitting the fault signal.

The fault detection method of the above embodiment enables multiple fault detections before and after the charging device charges the load. By the detection method, whether the main loop relay of the charging equipment is adhered or stuck can be detected, and whether the output end of the charging equipment is short-circuited can be detected, so that the risk of the charging equipment breaking down is reduced to a great extent.

Although the transistor is exemplified in the above embodiments, it is understood that the semiconductor element may be another type of switching element having a voltage threshold as a trigger condition.

The present disclosure also proposes a charging device comprising a fault detection apparatus according to any of the above embodiments.

Thus, while the present invention has been described with reference to specific examples, which are intended to be illustrative only and not to be limiting of the invention, it will be apparent to those of ordinary skill in the art that changes, additions or deletions may be made to the disclosed embodiments without departing from the spirit and scope of the invention.

Claims

1. A fault detection arrangement in a charging device comprising a first relay coupled between a first electrical input and a first electrical output and a second relay coupled between a second electrical input and a second electrical output, the fault detection arrangement comprising:

a first detection module coupled between the first electrical input and the second electrical output and configured to output a first detection signal upon fault detection;

a second detection module coupled between the second electrical input and the first electrical output and configured to output a second detection signal upon fault detection; and

a control module configured to receive the first detection signal and the second detection signal, and determine whether the first relay and the second relay are malfunctioning and whether a short circuit occurs between the first electrical output and the second electrical output according to the first detection signal and the second detection signal.

2. The fault detection device of claim 1, further comprising a first switch module and a second switch module, wherein the control module is further configured to control the first switch module and the second switch module according to a predetermined timing sequence, and wherein the control module is further configured to control the first switch module and the second switch module according to a predetermined timing sequence

The first switching module is coupled in series with the first detection module and configured to cause the first detection module to turn on or off fault detection via control of the control module;

the second switching module is coupled in series with the second detection module and is configured to cause the second detection module to turn on or off fault detection via control of the control module.

3. The fault detection device of claim 2, wherein the first switching module comprises:

a third relay coupled in series with the first detection module; and

a first semiconductor element having a first pole coupled to the coil of the third relay, a control pole coupled to the control module, and a second pole coupled to ground potential, wherein the first semiconductor element drives the contacts of the third relay to close or open in response to control of the control module, thereby causing the first detection module to turn on or off fault detection.

4. The fault detection device of claim 2, wherein the second switch module comprises:

a fourth relay coupled in series with the second detection module; and

and a second semiconductor element, wherein a first pole of the second semiconductor element is coupled to the coil of the fourth relay, a control pole of the second semiconductor element is coupled to the control module, and a second pole of the second semiconductor element is coupled to the ground potential, wherein the second semiconductor element is used for responding to the control of the control module and driving the contact of the fourth relay to be closed or opened so as to enable the second detection module to switch on or off fault detection.

5. The fault detection device of claim 1, wherein the first detection module comprises:

and a first optical coupler, wherein a light emitting element of the first optical coupler is coupled between the first electrical input end and the second electrical output end, and a light receiving element outputs the first detection signal, wherein when a current flows through the light emitting element, the first detection signal is at a low level, otherwise, the first detection signal is at a high level.

6. The fault detection device of claim 1, wherein the second detection module comprises:

and a second optical coupler, wherein a light emitting element of the second optical coupler is coupled between the second electrical input end and the first electrical output end, and a light receiving element outputs the first detection signal, wherein when a current flows through the light emitting element, the second detection signal is at a low level, otherwise, the second detection signal is at a high level.

7. The fault detection device according to claim 1, further comprising:

a first current limiting module coupled in series with the first detection module and configured to reduce current flow through the first detection module; and

a second current limiting module coupled in series with the second detection module and configured to reduce current flow through the second detection module.

8. The fault detection device of claim 7, wherein the first current limiting module includes at least a first resistor and the second current limiting module includes at least a second resistor.

9. The fault detection device of claim 1, wherein an alternating current is provided between the first electrical input and the second electrical input, and further comprising:

a first rectification module coupled in series with the first detection module and configured to rectify the alternating current when the first electrical input is in communication with the second electrical input via the second relay; and

a second rectification module coupled in series with the second detection module and configured to rectify the alternating current when the first electrical input is in communication with the second electrical input via the first relay.

10. The fault detection device of claim 9, wherein the first rectification module comprises a first diode and the second rectification module comprises a second diode.

11. The fault detection device of claim 1, wherein determining whether the first relay and the second relay are malfunctioning and whether there is a short circuit between the first electrical output and the second electrical output based on the first detection signal and the second detection signal further comprises:

judging whether the first detection signal and the second detection signal accord with a group of preset signals or not;

if so, it is determined that the first relay and the second relay are not malfunctioning and that there is no short circuit between the first electrical output and the second electrical output.

12. The fault detection device of claim 1, wherein the control module is further configured to:

and controlling the first relay and the second relay to be closed or opened according to a preset time sequence.

13. A charging apparatus, characterized in that it comprises a fault detection device according to any one of claims 1 to 12.