DE102019103036A1 - Charging station with a combination switch module - Google Patents

Abstract

A device for charging an electric vehicle (3) is provided which has a switching module (5) which can assume two switching states, with a charging voltage being applied to a charging plug only in the first switching state. The device also has a fault current sensor (12) and a release unit (13), the switching module (5) being switched to the second switching state in the event of a fault current and being switched to the first switching state when the charging is enabled. The switching module (5) is set up to switch to the second switching state in the event of a short circuit and an overload state, these states either being detectable within the switching module (5) itself or being detectable by means of an external line protection sensor (11) and being transmitted of a line protection signal to the switching module cause switching to the second switching state. Furthermore, a corresponding operating method for a device for charging an electric vehicle is provided.

Description

The present invention relates to a charging station with a combination switching module in which several event-based switching functions are combined.

Since high currents occur when charging an electric vehicle at a charging station or at a charging point, numerous safety standards are defined which a charging station must meet. According to the international standard IEC 61851, line protection, residual current protection and safe charging current release must be implemented on a charging station. The line protection includes the classic protection against short circuits and overcurrent conditions. This means that in the event of a short circuit or overload, all phases and optionally the neutral conductor are de-energized. The residual current protection includes switching off the charging voltage in the event of a differential current between the phase or phases and the neutral conductor and thus represents the classic residual current protection, which is implemented by means of an FI circuit breaker. The safe charging current release includes a switching device to ensure that a voltage is only applied to the charging cable or the charging plug when the charging plug has been plugged into the vehicle to be charged. The charging current release ensures that the charging cable is only live when the charging plug is plugged in.

In practice, the protective functions prescribed by the IEC 61851 standard are covered by various components. According to a known scenario, the line protection is implemented by means of a line circuit breaker (also referred to as LS switch for short), the residual current protection by means of an FI switch (RCD - residual current device) and the charging current release by means of a contactor. These switching components are all arranged in the charging path of the charging station and are individually triggered based on events. Since each of these components is associated with costs, according to another known scenario, the line protection and the residual current protection are covered together by one component, which is referred to as RCBO (Residual Current Operated Circuit-Breaker with Overcurrent Protection) and the combination of a circuit breaker (MCB) with a Fl circuit breaker.

The object of the invention is to provide a charging column with a compact and cost-saving design and a charging method that can be carried out with it.

A solution for this is provided by the device for charging an electric vehicle and by a corresponding operating method of the device according to the independent patent claims. Further configurations emerge from the dependent patent claims and the accompanying description.

The inventive device for charging an electric vehicle, hereinafter referred to as a charging station, has a switching module, wherein a charging voltage is applied to a charging plug connector in a first switching state of the switching module and the plug is voltage-free in a second switching state of the switching module. An electric vehicle connected to the charging station with a plug and charging cable can only be charged in the first switching state of the switching module. The charging station, which is also referred to as EVSE (electric vehicle supply equipment), can be designed as a single-phase or as a multi-phase system and be set up for both direct current and alternating current charging.

The charging column according to the invention also has a fault current sensor which is set up to indicate the presence of a fault current by means of a fault current signal, whereupon the switching module is switched to the second switching state, and a release unit which is set up to enable the provision of the charging voltage at the charging plug by means of a Display release signal, whereupon the switching module is switched to the first switching state. Both the fault current sensor and the release unit represent external units that can generate event-based switchover pulses and output them via fault current signal or release signal. The corresponding events, i.e. The presence of a fault current or release for the charging voltage communicates and causes a change in the switching state of the switching module. Both signals can be transmitted to a processing unit, which processes the two signals and controls the switching module accordingly, or can be transmitted directly to the switching module so that the switching module is controlled directly by means of the two signals. By combining different control paths for the supply of voltage in a switching module, this can therefore be referred to as a combination switching module.

The switching module of the charging station according to the invention is also set up to switch to the second switching state in the event of a short circuit and / or in the presence of an overload state (this can, but does not have to be caused by a short circuit), with these error states either being detectable within the switching module itself are (are detected) and switching the switching module to the second Cause switching state or are detectable by means of an external line protection sensor (are detected) and cause switching to the second switching state by transmitting a line protection signal to the switching module.

In the case of the charging station according to the invention, a single switching element is used to implement all three functions that are prescribed in accordance with the IEC 61851 standard. The switching module is therefore the only central switching element of the charging station that opens the switchable connection between the vehicle and the power source of the charging station (power supply and / or buffer storage) as a function of control signals - fault current signal, release signal and, if necessary, line protection signal, if detected externally by sensors or closes. In general, these signals can be analog or digital. The signals can comprise electronic or optical signals.

In a first embodiment of the charging station according to the invention, the line protection is implemented by sensors outside the switching module, i.e. externally, and the switching module is electronically controlled in the event of a short circuit or overload so that it switches to the second switching state. In the first embodiment, all three events - the presence of a fault current, the release of the charging voltage and the presence of a short circuit or an overload - are recorded externally, that is to say outside the switching module, and transmitted to it or to an intermediate processing unit. In the first embodiment, the switching module can be set up as a contactor. With regard to line protection (and also with regard to the other two functions), the contactor only represents the corresponding protective function insofar as it can switch to the second switching state if it is controlled externally on the basis of the line protection signal provided by the line protection sensor. The contactor does not offer any hardware protection against short circuits and overcurrents like a line circuit breaker, but corresponds to a purely switching component.

According to further embodiments of the charging station with a contactor as a switching module, the switching state of the switching module can be determined by means of a switching signal which is formed as a function of the fault current signal, the release signal and the line protection signal. The switching signal can be generated by the processing unit which is coupled to the three external sensors, i.e. to the release unit (also understood as a sensor in the context of the description), to the residual current sensor and to the line protection sensor. By evaluating the signals which are provided by the external sensors, the processing unit can control the switching module. The switching module can have a switching interface and be configured to be switched by means of the switching signal transmitted to this interface. In other words, the signals transmitted by the three sensors, each of which is associated with the presence of a different event, can act directly or indirectly on the same interface of the switching module and effect a switchover of the switching module in the same way. It goes without saying that a prioritization of the signals can be implemented, so that, for example, in the event of a fault current, the switching module cannot be switched to a conductive state by the release signal.

In a second embodiment of the charging station, the switching module is set up as a remotely controllable circuit breaker. The line protection is integrated in the hardware of the switch module and the presence of a short circuit and / or an overload directly influences components within the switch module itself, which in turn leads to the interruption of the current path within the switch module. In other words, a short circuit or an overcurrent itself serves as a switching pulse and immediately triggers a primary switching mechanism within the switching module, whereby the charging circuit is interrupted. In this case, triggering mechanisms known from the prior art can be used, which are used in conventional circuit breakers, such as triggering in the event of an overload by thermally induced bending of a bimetal element or triggering in the event of a short circuit by means of an electromagnet. In the second embodiment of the charging station, the corresponding mechanisms for providing line protection are integrated in the switch module and there is no transmission of any line protection signal from a line protection sensor external to the switch module to the switch module.

According to further embodiments of the charging column with a remotely controllable circuit breaker as a switching module, this can have a further, preferably reversible switching mechanism, by means of which the switching state of the switching module can be determined in analogy to the primary switching mechanism. The contacts of the further switching mechanism, which are separated when triggered, can also be automatically closed again if the signal controlling the further switching mechanism is absent or changes. The position of the further switching mechanism can be determined or switched solely as a function of the fault current signal and the release signal. For example, the further switching mechanism can be switched by mechanical rotation. By rotating an element Furthermore, the spring-return contacts present in the switching module can be opened and, in the idle state (for example, if the torque is missing), return to their starting position and close. In contrast to this, the first switching mechanism within the switching module, which corresponds to the primary switching mechanism of the remotely controllable line circuit breaker and which is triggered when a short circuit and / or overload is present, can be irreversible. This means that the corresponding contacts are not closed again by a spring return force, but have to be reset mechanically, usually by means of a lever attached to the LS switch. The further switching mechanism, which can be triggered as a function of the fault current signal and the release signal, is separate from the first switching mechanism and does not affect it. In other words, the release signal and the error signal cannot develop any mechanical switching effect on the first switching mechanism of the switching module. Consequently, the two switching mechanisms can be understood as two competing, mutually independent switching mechanisms within the switching module.

According to further embodiments of the charging column with a remotely controllable circuit breaker as a switching module, the charging column can also have an actuator which is coupled to the further switching mechanism and is set up to determine the switching state of the further switching mechanism as a function of the fault current signal and the enable signal. The actuator can be controlled directly by the fault current signal and the release signal or by a processing unit that receives these signals, evaluates them and controls the actuator accordingly.

The actuator can be a remote-automatic magnetic switch. In this context, an actuator, in particular in the form of a remotely automatic magnetic switch, is a component that generates a mechanical movement, such as a translational movement or, in particular, a rotary movement, by means of an electrical control. This mechanical movement is used to actuate the further switching mechanism of the switching module. In particular, the magnetic switch can rest directly on the switching module or be mounted directly next to it. Remotely controllable magnetic switches of the type described are well known from the prior art and are available on the market. However, it should be understood that the actuator does not necessarily have to have a magnetic switch, but can also have a piezoelectric actuator.

Regardless of the specific implementation of the charging column according to the invention, in addition to the lower space requirement due to the reduction of components and the lower power loss due to the reduction in contacts to be switched, lower costs can also be mentioned as advantages of the charging column according to the invention.

Furthermore, a method for operating a device for charging an electric vehicle is provided which has a switching module that can adopt one of the two switching states that have already been declared. According to the method according to the invention, the switching module switches to the first switching state if a release of the charging voltage is indicated by means of a release signal which comes from a release unit, and to the second switching state when the presence of a fault current is indicated by means of a fault current signal from a fault current sensor. In addition, the switching module switches to the second switching state in the event of a short circuit or an overcurrent, the detection of the short circuit or the overcurrent either taking place within the switching module itself or in an external line protection sensor and being displayed or communicated by means of a line protection signal provided by the line protection sensor.

It goes without saying that the features mentioned above and those yet to be explained below can be used not only in the respectively specified combination, but also in other combinations or on their own, without departing from the scope of the present invention.

• 1A zeigt eine Ladeinfrastruktur auf Basis einer ersten Ausführungsform der erfindungsgemäßen Ladesäule.
• 1 B zeigt eine Ladeinfrastruktur auf Basis einer zweiten Ausführungsform der erfindungsgemäßen Ladesäule.
• 2 zeigt einen schematischen Aufbau des Schaltmoduls in der Ladesäule gemäß der zweiten Ausführungsform der Erfindung.
• 3 zeigt einen Aufbau eines fernauslösbaren Leistungsschalters.
• 4 zeigt einen beispielhaften Aufbau eines fernautomatischen Magnetschalters.

Further advantages and configurations of the invention emerge from the description and the accompanying drawings.

• 1A shows a charging infrastructure based on a first embodiment of the charging column according to the invention.
• 1 B shows a charging infrastructure based on a second embodiment of the charging column according to the invention.
• 2 shows a schematic structure of the switching module in the charging station according to the second embodiment of the invention.
• 3 shows a structure of a remotely tripping circuit breaker.
• 4th shows an exemplary structure of a remote-automatic magnetic switch.

In 1A is a greatly simplified structure of a charging infrastructure 1 illustrated based on the first embodiment of the charging station according to the invention. The charging station can essentially be used as a Interface between a higher-level power supply 2 (e.g. power grid and / or buffer storage) and the electric vehicle 3 be understood. The electrical connection between these two units is by means of four cables 4th illustrates, which exemplarily represent three phases and a neutral conductor. The charging station itself is controlled by the switching module 5 represents. Depending on the switching status of the switching module 5 there is an electrical connection between the power supply 2 and the electric vehicle 3 , the explicit representation of the charging cable including the charging plug attached to it has been omitted for the sake of simplicity. In the normal or properly running charging case, all contacts are within the switching module 5 closed (first switching state), so that a charging voltage is applied to the charging plug and the electric vehicle via the current-carrying lines 5 is loaded. In 1A is the switching module 5 shown in its open or non-conductive state (second switching state), in which the charging circuit is interrupted.

The switching module 5 has a switching interface 6 on which the switching status of the switching module 5 can be determined. At the in 1A The first embodiment of the charging station according to the invention shown is the switching module 5 by means of the switching interface 6 from a group 10 controlled by external sensors (directly or indirectly by means of an intermediate processing device), all of which by means of a control circuit 7th to the switching interface 6 are coupled. The group 10 the external sensors has a line protection sensor 11 , a fault current sensor 12th and a release unit 13th (is also understood as a sensor), the functions of which have already been explained in detail. These three external sensors 11-13 are used to record the events assigned to them and to control the switching module accordingly 5 set up. The three external sensors 11-13 are with regard to their control path of the switching module 5 are equivalent and all have a direct or indirect effect (e.g. via a processing unit that receives the signals from the sensors 11-13 receives and the switching interface 6 controls accordingly) to the switching interface 6 a. The switching module 5 is designed as a contactor without any further special functionalities.

In 1 B is a greatly simplified structure of a charging infrastructure 1 illustrated based on the second embodiment of the charging station according to the invention. Since the structure of the in 1A is very similar, the same elements are given the same reference numerals and their interaction is not described again. In contrast to the in 1A Outlined structure of the charging station according to the invention is used in the in 1B The structure shown is a remotely controllable LS switch as a switching module 5 used. The remotely controllable LS switch is hardware-wise set up to detect short circuits and overloads internally and, if necessary, to open the switching contacts contained therein. Hence the group includes 10 of the external sensors only the residual current sensor 12th and the release unit 13th on. The external line protection sensor 10 out 1A not applicable, as its functionality is integrated in the remotely controllable LS switch, which acts as a switching module 5 acts. In addition, the first switching mechanism is by means of which the switching module 5 in 1B in the event of a short circuit or overload, the second switching mechanism, which is triggered by the signals from the external sensors 12th , 13th is triggered, spatially and structurally separated. This aspect is illustrated in greater detail using the illustration in 2 explained.

In 2 is a structure of the remotely controllable LS switch 20th shown. For the sake of simplicity, there is only one line 4th shown, which by the remotely controllable LS switch 20th is protected against short circuit and overload. The remotely controllable LS switch 20th has a primary switching mechanism 22nd on, which can have the usual safety switching mechanisms arranged in an LS switch in order to trigger it (ie interrupt the current path) in the event of a short circuit or overload. The primary switching mechanism works in the corresponding error scenario 22nd mechanically on the switching contact 21st (indicated by a large arrow) and open it. This effect brought about by the first arrow 24 is not brought about by external control signals, but by detecting a short circuit or overload directly in the remotely controllable LS switch 20th itself. To cover the other two functions, the remotely controllable LS switch 20th also another switching mechanism 23 on. This also acts on the switching contact 21st of the remote-controllable LS switch 20th but is separate and independent from the primary switching mechanism. The further switching mechanism will 23 is operated by an external actuator 26th activated or actuated. This effect is through the second arrow 25 represents. The actuator 26th is activated depending on the fault current signal and the enable signal.

In 3 Figure 3 is a cross-sectional view of a remotely controllable circuit breaker 20th shown. The remotely controllable LS switch 20th Overall, it has a very similar structure to the usual LS switch. The general mode of operation of an LS switch is not explained in detail here, since it is well known to the person skilled in the art. The remotely controllable LS switch 20th has a first connection terminal 31 and a second connection terminal 32 by means of which an electrical connection to the line to be protected (e.g. line 4th in 2 ) will be produced. The primary switching mechanism 22nd usually has a bimetal strip, which provides thermal release in the event of an overload, and a coil, which provides electromagnetic release in the event of a short circuit. The primary switching mechanism 22nd and the further switching mechanism 23 are structurally separate from each other, but both have an effect on the switching contact 21st . The further switching mechanism 23 is via a mechanical switching interface 33 actuated, which here has the shape of a rotatable pin as an example. By turning the pen, illustrated by the double arrow 34 , the further switching mechanism can 23 to be triggered. By one in the further switching mechanism 23 implemented spring return can be the switch contact 21st be closed again when at the switching interface 33 no force is exerted by the actuator. Therefore, it is the further switching mechanism 23 a reversible switching mechanism.

An exemplary actuator in the form of a remote-automatic magnetic switch 40 , which can be used for remote control of the further switching mechanism, is shown in 4th shown. The mechanics in the remote automatic magnetic switch 40 is spring reset, so that in the de-energized / resting state by means of a spring in the magnetic switch 40 the overall system, i.e. the charging station, is kept “open” or de-energized. The switch contact is used to activate the entire system 21st within the switching module 20th closed (see 2 and 3 ). The magnetic switch 40 has a solenoid 41 on which a metal pin 42 protrudes, which in turn with a swivel joint 43 is mechanically coupled. Apply voltage to the solenoid 41 so the pen is applied 41 moves along its longitudinal axis and exerts a force on the pivot joint 43 on. The upper part of the swivel joint 43 is by means of a spring 45 flexibly hung. The end point 46 on the lower part of the swivel joint 43 is coupled to the switching interface of the further switching mechanism, for example to the rotatable pin 33 in 3 . By applying a voltage to the solenoid 41 becomes the pivot point of the swivel joint 43 moved, for example by the solenoid 41 away, and thereby the end point 46 of the swivel joint in rotation. The further switching mechanism can be triggered by means of this rotation. The spring return force of the remote automatic magnetic switch 40 in its inactive state is stronger or stiffer than the spring restoring force of the spring of the spring-loaded further switching mechanism in the remotely controllable circuit breaker, so that the circuit breaker in the event of a fault (fault current or withdrawal of the charging current release) by the spring force of the remote-automatic magnetic switch 40 against the restoring force of the spring in the further switching mechanism of the LS switch can be opened or switched non-conductive. To the remotely controllable magnetic switch 40 To transmit the provided rotary movement to the remotely triggered LS switch, these two components can be mounted directly next to each other.

According to the second embodiment of the charging station according to the invention, a remotely triggered circuit breaker is used which, in addition to the actual line protection, is also used in the event of a fault current and to electrically switch the entire system (ie the charging station) on and off. The line protection is conventionally implemented by the LS switch, while in the event of a fault current and to activate or deactivate the charging current supply, the actuator, preferably the magnetic switch 40 , is controlled. As a result, the switching contact in the switching module can be opened and closed by means of the mechanical switching interface on the further switching mechanism. The switching contact is disconnected or closed in the event of a fault current and in the case of the charging current release (or when the charging current release is withdrawn) according to the same principle.

Claims (9)

A device for charging an electric vehicle (3), which has a switching module (5), wherein in a first switching state of the switching module (5) a charging voltage is applied to a charging plug and in a second switching state of the switching module (5) the charging plug is voltage-free; the apparatus further comprising: a fault current sensor (12) which is set up to indicate the presence of a fault current by means of a fault current signal, whereupon the switching module (5) is switched to the second switching state; and a release unit (13) which is set up to indicate the release of the provision of the charging voltage on the charging plug by means of a release signal, whereupon the switching module (5) is switched to the first switching state; wherein the switching module (5) is also set up to switch to the second switching state in the event of a short circuit and in the presence of an overload state, these states either being detectable within the switching module (5) itself and causing the switching to the second switching state or by means of a external line protection sensor (11) can be detected and cause the switching to the second switching state by transmitting a line protection signal to the switching module. Device according to Claim 1 , wherein the switching module (5) is set up as a contactor. Device according to Claim 2 , wherein the switching state of the switching module (5) can be determined by means of a switching signal which is formed as a function of the fault current signal, the release signal and the line protection signal. Device according to Claim 3 , wherein the switching module (5) has a switching interface (6) and is set up to be switched by means of the switching signal transmitted to the interface. Device according to Claim 1 , wherein the switching module (5) is set up as a remotely controllable circuit breaker. Device according to Claim 5 wherein the switching module (5) has a further switching mechanism (23), the switching state of which can be determined as a function of the fault current signal and the enable signal. Device according to Claim 6 , further comprising: an actuator (26) which is coupled to the further switching mechanism (23) and is set up to determine the switching state of the further switching mechanism as a function of the fault current signal and the release signal. Device according to Claim 7 , wherein the actuator is set up as a remote automatic magnetic switch (40). Method for operating a device for charging an electric vehicle (3), which has a switching module (5), wherein in a first switching state of the switching module (5) a charging voltage is applied to a charging plug and in a second switching state of the switching module (5) the charging plug is de-energized is; wherein the switching module (5) switches to the first switching state if a release of the charging voltage is indicated by means of a release signal which comes from a release unit (13); wherein the switching module (5) switches to the second switching state when the presence of a fault current is indicated by means of a fault current signal from a fault current sensor (12); and wherein the switching module (5) switches to the second switching state in the event of a short circuit or an overcurrent; and wherein the detection of the short circuit or the overcurrent either takes place within the switching module (5) or takes place in an external line protection sensor and is displayed by means of a line protection signal provided by an external line protection sensor (11).

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