Warning and break system for charging of electric vehicle

Abstract

The present invention provides a leakage alarm and leakage cutoff system for an electric vehicle charger, comprising: a plurality of DC power supply units connected in parallel to a leakage circuit breaker connected to a commercial power source; an AC leakage detector (AC Sensor) installed on the AC input side of each DC power supply unit; a DC leakage detector (DC Sensor) installed on the DC output side, which is the starting point of the connection cable of the DC power supply unit; a connection cable (connector) that connects the DC power generated by the DC power supply unit to the battery of the electric vehicle through the electric vehicle inlet, and a leakage alarm; and a control device that receives signals from the AC leakage detector and the DC leakage detector, calculates the leakage current, and operates the leakage circuit breaker and the leakage alarm according to the leakage state. This leakage alarm and leakage cutoff system for electric vehicle chargers can avoid unnecessary power outages caused by short-term leakage currents resulting from moisture during rain, and is effective in preventing the leakage circuit breaker from operating by delaying its activation time. In addition, it is possible to avoid electrical fires caused by insulation degradation of the internal electrical circuit of the charger and unexpected power outages of the charger. It is also designed to issue a leakage alarm when the AC leakage current reaches 15mA, so if the charger manager identifies the cause and takes precautionary measures in advance, it is effective in preventing leakage fires or unexpected power outages of the charger. In addition, the charger of the present invention is configured by combining several DC power supply modules in parallel, and an AC leakage current detector is separately installed for each module, so that a faulty module can be easily found, thereby reducing the time required for repair in the event of a failure.

Description

Technology Field

[0001] The present invention relates to a leakage current alarm and leakage current cutoff system for an electric vehicle charger, and more specifically, to a leakage current alarm and leakage current cutoff system for an electric vehicle charger that detects the leakage current of the charger to issue a leakage current alarm and provides a time delay for the leakage current cutoff to prevent unnecessary tripping of the leakage current cutoff circuit breaker. Background Technology

[0002] Generally, an electric vehicle is a vehicle powered by electricity; rather than obtaining driving energy from the combustion of fossil fuels, it obtains driving energy by rotating a motor with electrical energy stored in a battery.

[0003] For these electric vehicles, a battery serving as the power source for the motor is an essential component, and this battery must be charged frequently to provide power to the motor. Therefore, for charging electric vehicles, a battery connected via a charger, rather than a fossil fuel gas station, is essential.

[0004] In particular, the electric vehicle fast charger consists of a DC power supply that converts commercial AC power into DC, and a coupler that connects the DC power to the electric vehicle battery through the electric vehicle's connector and inlet.

[0005] However, since most chargers are installed outdoors, there is a high risk of accidents involving electrical leakage or electric shock due to moisture during rain. If moisture accumulates in the charger's electrical circuit during rain, it can cause leakage current. Currently, most chargers immediately activate the leakage circuit breaker to cause a power outage if the leakage current exceeds the specified limit. Consequently, frequent power outages cause inconvenience to users.

[0006] If the charger is in a state of high humidity, the heat generated by the leakage current can lead to a fire, so the charger must be disconnected from the power source by operating the leakage circuit breaker. However, if the humidity is not high, the moisture often evaporates due to the heat generated by the leakage current, causing the leakage to stop. Therefore, in the latter case, it is advisable to prevent the leakage circuit breaker from operating to avoid power outages to the charger.

[0007] The present invention provides a technology that can prevent unnecessary power outages in a charger depending on the moisture conditions. Prior art literature

[0008] Korean Registered Patent Publication No. 10-2413963 The problem to be solved

[0009] The present invention has been devised to solve the above-mentioned problems. The objective of the present invention is to solve the problem of frequent power outages caused by leakage current due to moisture when a charger is installed outdoors, and to provide a leakage current cutoff system capable of preventing unnecessary power outages of the charger by detecting leakage current that dissipates instantaneously. means of solving the problem

[0010] The present invention provides a means to solve the above-mentioned problems, and the present invention provides a leakage alarm and leakage cutoff system for an electric vehicle charger, comprising: providing a DC power supply unit connected in parallel to a leakage circuit breaker connected to a commercial power source; installing an AC leakage detector (AC Sensor) on the AC input side of each DC power supply unit; installing a DC leakage detector (DC Sensor) on the DC output side, which is the starting point of the connection cable of the DC power supply unit; including a connection cable (connector) that connects the DC power generated by the DC power supply unit to the battery of the electric vehicle through the electric vehicle inlet and a leakage alarm; and a control device that receives signals from the AC leakage detector and the DC leakage detector, calculates the leakage current, and operates the leakage circuit breaker and the leakage alarm according to the leakage state. Effects of the invention

[0011] As described above, the leakage current alarm and leakage current cutoff system for an electric vehicle charger according to the present invention can avoid unnecessary power outages in the charger caused by short-term leakage currents resulting from moisture during rain, and thus has the effect of delaying the operation time of the leakage current cutoff device so that the device does not operate.

[0012] In addition, it is possible to avoid electrical fires caused by insulation degradation of the internal electrical circuit of the charger and unexpected power outages of the charger. It is also designed to issue a leakage alarm when the AC leakage current reaches 15mA, so if the charger manager identifies the cause and takes precautionary measures in advance, it is effective in preventing leakage fires or unexpected power outages of the charger.

[0013] In addition, the charger of the present invention is configured by combining several DC power supply modules in parallel, and an AC leakage current detector is separately installed for each module, so that a faulty module can be easily found, thereby reducing the time required for repair in the event of a failure. Brief explanation of the drawing

[0014] Figure 1 shows the configuration of the electric vehicle charger of the present invention. Figure 2 shows the configuration and function of the control device. Figure 3 shows the interruption time delay characteristics for AC leakage current. Curve A is the AC human electric shock protection standard, and Curve B is the AC electric shock cutoff characteristic of this product. Figure 4 shows the interruption time delay characteristics for DC leakage current. Curve A is the DC human electric shock protection standard, and Curve B is the DC electric shock blocking characteristic of this product. Specific details for implementing the invention

[0015] Before describing various embodiments of the present invention in detail, it will be understood that the application is not limited to the details of the configuration and arrangement of components described in the following detailed description or illustrated in the drawings. The present invention may be embodied and practiced in other embodiments and may be carried out in various ways. Furthermore, it will be understood that the expressions and terms used herein regarding device or element orientations (e.g., "front," "back," "up," "down," "top," "bottom," "left," "right," "lateral") are used merely to simplify the description of the present invention and do not indicate or imply that the related device or element must simply have a specific orientation. Additionally, terms such as "first" and "second" are used in this and the appended claims for illustrative purposes and are not intended to indicate or imply relative importance or intent.

[0016] The present invention has the following features to achieve the above objective.

[0017] Preferred embodiments of the present invention will be described in detail below with reference to the attached drawings. Prior to this, terms and words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings. Instead, based on the principle that the inventor can appropriately define the concepts of terms to best describe his invention, they should be interpreted in a meaning and concept consistent with the technical spirit of the present invention.

[0018] Therefore, it should be understood that the embodiments described in this specification and the configurations illustrated in the drawings are merely the most preferred embodiments of the present invention and do not represent all of the technical ideas of the present invention, and that various equivalents and modifications that can replace them may exist at the time of filing this application.

[0019] As an embodiment of the present invention,

[0020] In a leakage alarm and leakage circuit breaker system for electric vehicle chargers,

[0021] A DC power supply unit (14) is provided, which is connected in parallel to a leakage circuit breaker (12) connected to a commercial power supply (11);

[0022] Each AC leakage detector (AC Sensor) (13) is installed on the AC input side of the above DC power supply (14);

[0023] A DC leakage detector (DC Sensor) (15) is installed on the DC output side, which is the starting point of the connection cable of the above DC power supply (14);

[0024] It includes a connector (16) that connects the DC power generated by the above DC power supply (14) to the battery of the electric vehicle through the electric vehicle inlet, and a leakage alarm (18);

[0025] The present invention relates to a leakage alarm and leakage cutoff system for an electric vehicle charger, comprising a control device (17) that receives signals from the AC leakage detector (13) and DC leakage detector (15), calculates the leakage current, and operates the leakage circuit breaker (12) and leakage alarm (18) according to the leakage state.

[0026] In addition, as another embodiment of the present invention,

[0027] The above control device (17) is configured to receive AC leakage current signals and DC leakage current signals detected by an AC leakage current detector (ACS, 13) and a DC leakage current detector (DCS, 15), and to calculate AC leakage current and DC leakage current at every cycle (1 / 60th of a second) of the power supply together with a power synchronization signal;

[0028] In order to ensure that there is no need to interrupt the leakage current when the leakage current is extinguished within a set time, if the calculated AC leakage current or DC leakage current exceeds the leakage current interruption threshold, a cutoff signal is sent to the leakage circuit breaker (12) after a set time delay;

[0029] It is configured so that the leakage alarm (18) is activated when the alternating current leakage exceeds the leakage alarm threshold.

[0030] In addition, as another embodiment of the present invention,

[0031] The above control device (17) activates the leakage alarm (18) when the calculated AC leakage current exceeds 15mA.

[0032] In addition, as another embodiment of the present invention,

[0033] The above control device (17) does not send a leakage circuit breaker signal until 0.15 seconds after the leakage occurs when the calculated AC leakage current is 30mA, and sends a leakage circuit breaker signal when the leakage continues for more than 0.15 seconds to operate the leakage circuit breaker (12).

[0034] When the calculated AC leakage current is 45mA, a leakage circuit breaker signal is not sent for up to 0.1 seconds after the leakage occurs, and if the leakage continues for more than 0.1 seconds, a leakage circuit breaker signal is sent to operate the leakage circuit breaker (12).

[0035] When the calculated AC leakage current exceeds 60mA, a cutoff signal is sent immediately so that the leakage circuit breaker (12) is immediately cut off.

[0036] In addition, as another embodiment of the present invention,

[0037] The above control device (17) does not send a leakage circuit breaker signal for up to 1 second after the leakage occurs when the calculated DC leakage current is 6mA, and sends a leakage circuit breaker signal when the leakage continues for more than 1 second to operate the leakage circuit breaker (12).

[0038] When the calculated DC leakage current exceeds 9mA, a cutoff signal is sent immediately so that the leakage circuit breaker (12) is immediately cut off.

[0040] Hereinafter, a leakage alarm and leakage cutoff system for an electric vehicle charger according to a preferred embodiment of the present invention will be described in detail with reference to FIGS. 1 to 4.

[0041] The leakage current alarm and leakage current cutoff system for an electric vehicle charger according to the present invention is composed of a leakage current cutoff circuit breaker, a DC power supply, an electric vehicle coupler (inlet and connector), a leakage current detector, and a control device.

[0042] A shunt (ST, tripping coil) is installed in the earth leakage circuit breaker, allowing the breaker to be tripped at any time by a tripping signal from the control device.

[0043] A DC power supply is a device that receives 3-phase 220 / 380V AC power and generates 1,000V DC power. To allow for various charger capacities, such as 100KW, 200KW, and 400KW, the DC power supply consists of 25KW modules. In other words, a 100KW charger uses four DC power supply modules connected in parallel.

[0044] One end of the connecting cable is connected to the DC output side of the DC power supply, and the other end is configured to connect to the electric vehicle battery through the electric vehicle's connector and inlet.

[0045] The leakage current detector consists of separate AC leakage current detectors and DC leakage current detectors. The AC leakage current detector is a standard ZCT (Zero-Sequence Current Transformer) and is installed on the AC input side of each DC power supply unit that is modular. The DC leakage current detector is a standard DC Zero-Sequence Current Transformer and is installed on the DC output side of the DC power supply unit. Since the DC side of the DC power supply unit that is modular is connected in parallel, one DC Zero-Sequence Current Transformer is installed per charger.

[0046] The control unit receives the AC and DC leakage current signals detected by the AC and DC leakage current detectors, processes them, and if the leakage current exceeds a threshold, sends a signal to the shunt of the earth leakage circuit breaker after an appropriate time delay to activate the breaker. Due to this appropriate time delay, the breaker does not send a tripping signal to the shunt in the event of short-term leakage currents caused by factors such as moisture, thereby preventing unnecessary tripping of the breaker—that is, unnecessary power outages for the charger.

[0047] In addition, if the AC leakage current exceeds the leakage alarm threshold, the leakage alarm is activated. When the leakage alarm is triggered, the administrator can investigate the cause of the leakage and take preventive measures, thereby preventing and avoiding power outages at the charger.

[0048] In addition, the leakage alarm and leakage cutoff system for an electric vehicle charger according to the present invention is composed of a part that supplies DC power and a part that controls leakage current, as shown in FIG. 1. The DC power supply part is composed of a leakage circuit breaker (12) connected to a commercial power source (11), a DC power supply device (14), and a connector (16) which is a connecting cable, and the leakage current control part is composed of an AC leakage detection sensor (13), a DC leakage detection sensor (15), a control device (17), and a leakage alarm (18).

[0049] A shunt (ST, circuit breaker coil) is installed in the leakage circuit breaker (12) so that the leakage circuit breaker (12) can be cut off at any time by a circuit breaker signal from a control device (17) using an AC leakage detection sensor (13) and a DC leakage detection sensor (15).

[0050] The DC power supply (14) is a device that receives 3-phase 220 / 380V AC power and produces 1000V DC power. To allow the charger's capacity to be varied, such as 100KW, 200KW, or 400KW, the DC power supply (14) is made of 25KW modules. That is, a charger with a capacity of 100KW uses four DC power supply modules connected in parallel.

[0051] One end of the connecting connector cable (16) is connected to the DC output side of the DC power supply, and the other end is connected to the battery through the inlet of the electric vehicle.

[0052] Leakage current is detected by an AC leakage current detector (13) and a DC leakage current detector (15). The AC leakage current detector (13) is a standard ZCT (zero-sequence current transformer) and is installed on the AC input side of each DC power supply unit (14) which is a module. The DC leakage current detector (15) is a standard DC zero-sequence current transformer and is installed on the DC output side of the DC power supply unit (14). Since the DC side of the DC power supply unit which is a module is connected in parallel, one DC zero-sequence current transformer is installed per charger at the starting point of the connection connector cable (16).

[0053] As shown in FIG. 2, the control device (17) receives the AC leakage current signal and the DC leakage current signal detected by the AC leakage current detector (ACS, 13) and the DC leakage current detector (DCS, 15), and calculates the AC leakage current and the DC leakage current at every cycle (1 / 60th of a second) of the power supply together with the power supply synchronization signal.

[0054] The leakage current protection standards for electric vehicle chargers are less than 30mA for AC leakage current and less than 6mA for DC leakage current [KC 61851-1, revised on 11-11, 2022, Electrical Appliance Safety Standard Section 8.5, leakage protection device].

[0055] The first function of the control device (17) is to send a cutoff signal to the leakage circuit breaker (12) after an appropriate time delay when the calculated AC leakage current or DC leakage current exceeds the leakage circuit breaker threshold. The reason for the time delay is that the generated leakage current may disappear after a short period of time, and if the leakage current disappears quickly, there is no need to cut off the leakage current. In other words, unnecessary power outages of the charger can be avoided in cases such as simple moisture during rain. The time delay of the cutoff signal is determined differently depending on the measured leakage current value, and the time delay is given within the range of protection against electric shock to the human body.

[0056] A typical example of a short circuit that dissipates quickly is a short circuit caused by moisture during rain. In other words, when a short circuit occurs due to moisture, the heat generated by the current often instantly removes the moisture, causing the current to disappear. Another example is when lightning strikes a power distribution line, causing the voltage of the commercial power supply to rise instantaneously and the leakage current on the AC side to increase momentarily.

[0057] In the case of AC leakage current, as shown in Fig. 3, a time delay is applied when the AC leakage current is 30mA or higher. In Fig. 3, curve A represents the AC human electric shock protection standard according to the Electrical Appliance Safety Standard KSC-IEC60947-2. Therefore, this charger must provide a time delay lower than this standard, and curve B represents the time delay characteristics determined by this charger. Specifically, a time delay of 0.15 seconds is applied at 30mA, and a time delay of 0.1 seconds is applied at 45mA. Furthermore, at 60mA or higher, leakage current interruption is performed as quickly as possible, which is 0.05 seconds or less.

[0058] In the case of DC leakage current, as shown in Fig. 4, a time delay is applied when the DC leakage current is 6mA or higher. In Fig. 4, curve A represents the DC human electric shock protection standard based on the DC-2 region b curve of the Electrical Appliance Safety Standard IEC 60947-1. Therefore, this charger must apply a time delay lower than this standard, and curve B represents the time delay characteristics determined by this charger. Specifically, a time delay of 1 second is applied at 6mA. Furthermore, at 9mA or higher, leakage current interruption is performed as quickly as possible, which is 0.4 seconds or less.

[0059] The second function of the control device (17) is to activate the leakage alarm (18) when the AC leakage current exceeds the leakage alarm threshold. The leakage alarm (18) uses a standard red LED light or a buzzer. When the leakage alarm (18) is activated, the administrator can prevent a power outage of the charger in advance by investigating the cause of the leakage and taking preventive measures. In the present invention, the leakage alarm threshold is set to 15mA AC.

[0060] As described above, although the present invention has been explained by limited embodiments and drawings, the present invention is not limited thereto and it is obvious that various modifications and changes are possible within the scope of the technical spirit of the present invention and the equivalent scope of the claims described below by those skilled in the art to which the present invention belongs. Explanation of the symbols

[0061] 11: Commercial power supply 12: Earth leakage circuit breaker 13: AC leakage current detector 14: DC power supply 15: DC leakage current detector 16: Connection cable 17: Control unit 18: Ground fault alarm

Claims

Claim 1 In a leakage alarm and leakage cutoff system for an electric vehicle charger, a DC power supply unit (14) is provided in a plurality of parallel connections to a leakage circuit breaker (12) connected to a commercial power supply (11); an AC leakage detector (AC Sensor) (13) is installed on the AC input side of each DC power supply unit (14); a DC leakage detector (DC Sensor) (15) is installed on the DC output side, which is the starting point of the connection cable of the DC power supply unit (14); and the system includes a connection cable (connector) (16) that connects the DC power generated by the DC power supply unit (14) to the battery of the electric vehicle through the electric vehicle inlet and a leakage alarm (18); It includes a control device (17) that receives signals from the AC leakage current detector (13) and the DC leakage current detector (15), calculates the leakage current, and operates the leakage circuit breaker (12) and the leakage alarm (18) according to the leakage state; the control device (17) is responsible for the function of sending a cutoff signal to the leakage circuit breaker (12) after a set time delay if the calculated AC leakage current or DC leakage current exceeds the leakage circuit breaker threshold; the control device (17) is configured to receive the AC leakage current signal and the DC leakage current signal detected by the AC leakage current detector (ACS, 13) and the DC leakage current detector (DCS, 15), and to calculate the AC leakage current and the DC leakage current every cycle (1 / 60th of a second) of the power supply together with the power synchronization signal; In order to avoid the need to cut off the leakage current when the leakage current disappears within a set time, the control device (17) is configured to send a cutoff signal to the leakage circuit breaker (12) after a set time delay if the calculated AC leakage current or DC leakage current exceeds the leakage current cutoff threshold; and is configured to activate the leakage alarm (18) if the AC leakage current exceeds the leakage alarm threshold; the control device (17) is configured to activate the leakage alarm (18) if the calculated AC leakage current exceeds 15mA; and the control device (17) does not send a leakage current cutoff signal until 0.15 seconds after the leakage occurs when the leakage current is 0.If it persists for more than 15 seconds, a leakage circuit breaker signal is sent to cause the leakage circuit breaker (12) to operate; if the calculated AC leakage current is 45mA, a leakage circuit breaker signal is not sent until 0.1 seconds after the leakage occurs, and if the leakage persists for more than 0.1 seconds, a leakage circuit breaker signal is sent to cause the leakage circuit breaker (12) to operate; and if the calculated AC leakage current exceeds 60mA, an immediate cutoff signal is sent to cause the leakage circuit breaker (12) to immediately cut off; The above control device (17) is characterized by not sending a leakage circuit breaker signal for up to 1 second after the leakage occurs when the calculated DC leakage current is 6mA, and sending a leakage circuit breaker signal to operate the leakage circuit breaker (12) when the leakage continues for more than 1 second, and sending an immediate circuit breaker signal to immediately cut off the leakage circuit breaker (12) when the calculated DC leakage current exceeds 9mA. Claim 2 delete Claim 3 delete Claim 4 delete Claim 5 delete

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