Disclosure of Invention
In view of the above, the invention provides a method and a device for insulation diagnosis of a multi-gun direct current charging pile, so as to accurately position an insulation fault vehicle.
A multi-gun direct-current charging pile insulation diagnosis method comprises the steps that a direct-current source, a plurality of non-isolated DC/DC conversion circuits and a plurality of charging guns are included, the input end of each non-isolated DC/DC conversion circuit is connected to the direct-current source in parallel, the output end of each non-isolated DC/DC conversion circuit is connected with one charging gun, and the multi-gun direct-current charging pile insulation diagnosis method comprises the following steps:
in the process that a plurality of electric vehicles are charged by a plurality of direct current charging piles simultaneously, whether the positive pole ground insulation impedance of each electric vehicle is lower than a first preset value and whether the negative pole ground insulation impedance of a direct current source is lower than a second preset value are detected;
when the anode-to-ground insulation impedance of the electric automobile is detected to be lower than a first preset value, judging that the anode-to-ground insulation fault of the electric automobile exists, and disconnecting the charging of the electric automobile;
and when the direct current source negative electrode ground insulation resistance is detected to be not lower than the second preset value, the charging of one electric automobile is cut off, and when the direct current source negative electrode ground insulation resistance is detected to be not lower than the second preset value, the last cut-off electric automobile negative electrode ground insulation fault is judged.
Optionally, the multi-gun dc charging pile insulation diagnosis method specifically includes:
when the fact that the ground insulation resistance of the negative electrode of the direct current source is lower than a second preset value is detected for the first time, the charging of the electric automobile which is connected to the multi-gun direct current charging pile for the last time is cut off.
Optionally, any one of the above disclosed methods for diagnosing insulation of a multi-gun dc charging pile further includes:
and if the insulation resistance of the negative pole of the direct current source to the ground is still lower than the second preset value after the last electric vehicle is disconnected from being charged, judging that the insulation resistance of the negative pole of the direct current source to the ground is in fault, and disconnecting the charging of all the electric vehicles.
Optionally, any one of the above disclosed methods for diagnosing insulation of a multi-gun dc charging pile further includes:
and detecting whether the insulation resistance of the anode of the direct current source to the ground is lower than a third preset value, if so, judging that the anode of the direct current source has an insulation fault to the ground, and disconnecting the charging of all the electric automobiles.
Optionally, any one of the disclosed multi-gun dc charging pile insulation diagnosis methods specifically includes:
and detecting the insulation resistance of the anode of the electric automobile to the ground and the insulation resistance of the cathode of the direct current source to the ground by a bridge method.
A multi-gun direct-current charging pile insulation diagnosis device comprises a direct-current source, a plurality of non-isolated DC/DC conversion circuits and a plurality of charging guns, wherein the input end of each non-isolated DC/DC conversion circuit is connected in parallel with the direct-current source, and the output end of each non-isolated DC/DC conversion circuit is connected with one charging gun respectively, wherein the multi-gun direct-current charging pile insulation diagnosis device comprises:
the detection unit is used for detecting whether the positive electrode ground insulation impedance of each electric vehicle is lower than a first preset value and whether the negative electrode ground insulation impedance of the direct current source is lower than a second preset value in the process that a plurality of electric vehicles are charged by a plurality of direct current charging piles simultaneously;
the first processing unit is used for judging the positive pole-to-ground insulation fault of the electric automobile and disconnecting the charging of the electric automobile when detecting that the positive pole-to-ground insulation impedance of the electric automobile is lower than a first preset value;
the second processing unit is used for disconnecting the charging of one electric automobile every time when the direct-current source negative electrode ground insulation impedance is detected to be lower than a second preset value, and judging the last disconnected electric automobile negative electrode ground insulation fault until the direct-current source negative electrode ground insulation impedance is detected to be not lower than the second preset value;
the multi-gun direct-current charging pile insulation diagnosis device comprises a processor and a memory, wherein the detection unit, the first processing unit and the second processing unit are stored in the memory as program units, and the processor executes the program units stored in the memory to realize corresponding functions.
Optionally, when the second processing unit detects that the ground insulation resistance of the negative electrode of the direct current source is lower than a second preset value for the first time, the charging of the electric vehicle which is connected to the multi-gun direct current charging pile for the last time is disconnected.
Optionally, any one of the above-mentioned disclosed insulating diagnostic device of stake of rifle direct current still includes:
and the third processing unit is used for judging that the DC source negative electrode insulation resistance is in fault and disconnecting the charging of all the electric automobiles if the DC source negative electrode insulation resistance is still lower than the second preset value after the last electric automobile is disconnected from being charged.
Optionally, any one of the above-mentioned disclosed insulating diagnostic device of stake of rifle direct current still includes:
and the fourth processing unit is used for detecting whether the earth insulation impedance of the positive electrode of the direct current source is lower than a third preset value, if so, judging that the earth insulation fault of the positive electrode of the direct current source occurs, and disconnecting the charging of all the electric automobiles.
Optionally, in any one of the above-disclosed multi-gun dc charging pile insulation diagnosis devices, the detection unit is specifically configured to detect the magnitude of the positive electrode-to-ground insulation resistance and the magnitude of the negative electrode-to-ground insulation resistance of the dc source of the electric vehicle by a bridge method.
According to the technical scheme, when the direct-current source negative electrode ground insulation impedance is detected to be too low, the charging of one electric vehicle is disconnected firstly, the direct-current source negative electrode ground insulation impedance is detected again, if the direct-current source negative electrode ground insulation impedance is increased at the moment, the negative electrode ground insulation fault of the electric vehicle can be confirmed, if the direct-current source negative electrode ground insulation impedance is still too low at the moment, the charging of the next electric vehicle is continuously disconnected … …, and by analogy, the vehicle with the negative electrode ground insulation fault can be found finally, and the probability that all the electric vehicles need to be disconnected from the charging is greatly reduced.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The embodiment of the invention discloses an insulation diagnosis method for a multi-gun direct-current charging pile, which is applied to the multi-gun direct-current charging pile shown in figure 1 to accurately position an insulation fault vehicle. As shown in fig. 2, the diagnostic method includes:
step S01: in the process that a plurality of electric vehicles are charged by a plurality of direct current charging piles simultaneously, whether the positive pole ground insulation impedance of each electric vehicle is lower than a first preset value and whether the negative pole ground insulation impedance of a direct current source is lower than a second preset value is detected.
Step S02: when the fact that the anode-to-ground insulation resistance of the electric automobile is lower than a first preset value is detected, the anode-to-ground insulation fault of the electric automobile is judged, and charging of the electric automobile is disconnected.
Step S03: and when the direct current source negative electrode ground insulation resistance is detected to be not lower than the second preset value, the charging of one electric automobile is cut off, and when the direct current source negative electrode ground insulation resistance is detected to be not lower than the second preset value, the last cut-off electric automobile negative electrode ground insulation fault is judged.
Specifically, assuming that M (M is equal to or less than N) electric vehicles are simultaneously charged in a certain scene by connecting to a multi-gun dc charging pile, referring to fig. 1, a non-isolated DCDC i (i is 1, 2, …, M) converts a dc source voltage into a charging voltage required by an electric vehicle i connected to a charging gun i, and charges the electric vehicle i.
According to the safety requirements, in the charging process, when the positive pole-to-ground insulation impedance RHI of the electric automobile i is too low, namely the positive pole-to-ground insulation fault of the electric automobile i, the charging of the electric automobile i needs to be disconnected, and when the negative pole-to-ground insulation impedance RLi of the electric automobile i is too low, namely the negative pole-to-ground insulation fault of the electric automobile i, the charging of the electric automobile i also needs to be disconnected.
The positive electrodes of the non-isolated DCDCDs are electrically isolated, whether the electric automobile i has a positive electrode-to-ground insulation fault can be judged simply according to the magnitude of the positive electrode-to-ground insulation impedance RHI of the electric automobile i, based on the judgment, the fact that the RHI is lower than a first preset value is considered to be too low, once the fact that the RHI is lower than the first preset value is detected, the fact that the positive electrode-to-ground insulation fault of the electric automobile i is judged, and charging of the electric automobile i is independently disconnected.
And the negative electrodes of the non-isolated DCDCDCCs are directly electrically connected, and when a certain electric vehicle has a negative electrode-to-ground insulation fault, the negative electrode-to-ground insulation impedances of the M electric vehicles are all reduced, so that whether the electric vehicle i has the negative electrode-to-ground insulation fault cannot be distinguished simply according to the resistance value of the RLi. Based on this, the embodiment of the invention detects the dc source negative pole-to-ground insulation resistance RL0 in real time, the dc source negative pole has direct electrical connection with the negative poles of the M electric vehicles, under the condition that the dc source negative pole-to-ground insulation fault is not considered, when RL0 is too low, it indicates that one of the M electric vehicles has a negative pole-to-ground insulation fault, at this time, the charging of one electric vehicle, such as the electric vehicle 1, is firstly disconnected, and if the RL0 is raised after the charging of the electric vehicle 1 is disconnected, it indicates that the electric vehicle 1 is the vehicle with the negative pole-to-ground insulation fault; if RL0 is still too low after the charging of electric vehicle 1 is disconnected, which indicates that electric vehicle 1 has no insulation fault of negative pole to ground, and the vehicle with the insulation fault of negative pole to ground is one of electric vehicles 2-M, the charging of one electric vehicle, for example, electric vehicle 2, is continuously disconnected … …, and so on, and the vehicle with the insulation fault of negative pole to ground can be found finally. After finding out the vehicle with the negative electrode insulation fault to the ground, the normal charging of the electric vehicles which are disconnected one by one in the prior art is recovered.
As can be seen from the above description, in the embodiment of the present invention, when it is detected that the dc source negative electrode insulation resistance to ground is too low, the charging of one electric vehicle is disconnected first, and the dc source negative electrode insulation resistance to ground is detected again, if the dc source negative electrode insulation resistance to ground is increased at this time, the negative electrode insulation fault to ground of the electric vehicle can be determined, and if the dc source negative electrode insulation resistance to ground is still too low, the charging of the next electric vehicle is continuously disconnected, … …, and so on, the vehicle with the negative electrode insulation fault to ground can be found finally, and the probability that all electric vehicles need to be disconnected from charging is greatly reduced.
Optionally, in the embodiment of the invention, when it is detected that the ground insulation impedance of the negative electrode of the direct current source is lower than the second preset value for the first time, the charging of the electric vehicle which is connected to the multi-gun direct current charging pile for the last time is selected to be disconnected. This is because: the instant that an electric vehicle with a negative pole-to-ground insulation fault is connected into a plurality of direct current charging piles to start charging can cause the impedance of the negative pole-to-ground insulation of a direct current source to be too low immediately, and the probability that the electric vehicle which is connected into the plurality of direct current charging piles to start charging is sudden with the negative pole-to-ground insulation fault at the instant is lower, so that the embodiment of the invention takes a new vehicle as the vehicle with the highest probability of the negative pole-to-ground insulation fault and preferentially disconnects the charging of the new vehicle.
Any of the embodiments disclosed above is performed in the case that the default multi-gun dc charging pile itself has no negative-electrode-to-ground insulation fault (i.e., the dc source has no negative-electrode-to-ground insulation fault), for example, the multi-gun dc charging pile always starts to operate only when the power-on self-test is passed. However, the fault that the negative pole is insulated to the ground suddenly in the working process of the multi-gun direct-current charging pile cannot be eliminated, so the embodiment of the invention also adds the following optional contents: and if the insulation resistance of the negative pole of the direct current source to the ground is still lower than the second preset value after the last electric vehicle is disconnected from being charged, judging that the insulation resistance of the negative pole of the direct current source to the ground has a fault, and disconnecting the charging of all the electric vehicles at the moment. The corresponding diagnostic method is shown in fig. 3 and comprises:
step S11: in the process that a plurality of electric vehicles are charged by a plurality of direct current charging piles simultaneously, whether the positive pole ground insulation impedance of each electric vehicle is lower than a first preset value and whether the negative pole ground insulation impedance of a direct current source is lower than a second preset value is detected.
Step S12: when the fact that the anode-to-ground insulation resistance of the electric automobile is lower than a first preset value is detected, the anode-to-ground insulation fault of the electric automobile is judged, and charging of the electric automobile is disconnected.
Step S13: when the ground insulation resistance of the negative electrode of the direct current source is detected to be lower than a second preset value every time, the charging of one electric vehicle is cut off;
step S14: after each charging of one electric vehicle is disconnected, if the direct-current source negative electrode ground insulation impedance is detected to be not lower than the second preset value, the last disconnected electric vehicle negative electrode ground insulation fault is judged; and if the insulation resistance of the negative pole of the direct current source to the ground is still lower than the second preset value after the last electric vehicle is disconnected from being charged, judging that the insulation resistance of the negative pole of the direct current source to the ground has a fault, and disconnecting the charging of all the electric vehicles at the moment.
Certainly, the positive electrode-to-ground insulation may also have no fault in the working process of the multi-gun direct-current charging pile, so that based on any one of the embodiments disclosed above, the following optional contents are added in the embodiment of the present invention: and detecting whether the insulation resistance of the anode of the direct current source to the ground is lower than a third preset value, if so, judging that the anode of the direct current source has an insulation fault to the ground, and disconnecting the charging of all the electric automobiles. The corresponding diagnostic method is shown in fig. 4 and comprises:
step S21: in the process that a plurality of electric vehicles are charged by a plurality of direct current charging piles simultaneously, whether the positive pole ground insulation impedance of each electric vehicle is lower than a first preset value, whether the negative pole ground insulation impedance of a direct current source is lower than a second preset value and whether the positive pole ground insulation impedance of the direct current source is lower than a third preset value are detected.
Step S22: when the fact that the anode-to-ground insulation resistance of the electric automobile is lower than a first preset value is detected, the anode-to-ground insulation fault of the electric automobile is judged, and charging of the electric automobile is disconnected.
Step S23: when the ground insulation resistance of the negative electrode of the direct current source is detected to be lower than a second preset value every time, the charging of one electric vehicle is cut off;
step S24: after each charging of one electric vehicle is disconnected, if the direct-current source negative electrode ground insulation impedance is detected to be not lower than the second preset value, the last disconnected electric vehicle negative electrode ground insulation fault is judged; and if the insulation resistance of the negative pole of the direct current source to the ground is still lower than the second preset value after the last electric vehicle is disconnected from being charged, judging that the insulation resistance of the negative pole of the direct current source to the ground has a fault, and disconnecting the charging of all the electric vehicles at the moment.
Step S25: and when the fact that the impedance of the anode-to-ground insulation of the direct current source is lower than a third preset value is detected, the anode-to-ground insulation fault of the direct current source is judged, and at the moment, charging of all electric vehicles is cut off.
The embodiment of the invention can detect the magnitude of the ground insulation impedance at any electrical node by adopting an electric bridge method, for example, the magnitude of the positive pole ground insulation impedance, the negative pole ground insulation impedance and the positive pole ground insulation impedance of the direct current source of the electric automobile by adopting the electric bridge method. Of course, other techniques may be used by those skilled in the art to detect the magnitude of the insulation resistance to ground at any electrical node, and are not limited herein.
Corresponding to the embodiment of the method, the embodiment of the invention also discloses a multi-gun direct current charging pile insulation diagnosis device; the multi-gun direct-current charging pile comprises a direct-current source, a plurality of non-isolated DC/DC conversion circuits and a plurality of charging guns, wherein the input end of each non-isolated DC/DC conversion circuit is connected to the direct-current source in parallel, and the output end of each non-isolated DC/DC conversion circuit is connected with one charging gun; as shown in fig. 5, the insulation diagnosis apparatus for a multi-gun dc charging pile includes:
the detection unit 100 is used for detecting whether the positive electrode ground insulation impedance of each electric vehicle is lower than a first preset value and whether the negative electrode ground insulation impedance of the direct current source is lower than a second preset value in the process that a plurality of electric vehicles are charged by a plurality of direct current charging piles simultaneously;
the first processing unit 200 is used for judging the positive pole-to-ground insulation fault of the electric vehicle and disconnecting the charging of the electric vehicle when detecting that the positive pole-to-ground insulation impedance of the electric vehicle is lower than a first preset value;
and the second processing unit 300 is configured to disconnect charging of one electric vehicle each time the dc source negative electrode ground insulation impedance is detected to be lower than a second preset value, and determine a last disconnected electric vehicle negative electrode ground insulation fault until the dc source negative electrode ground insulation impedance is detected to be not lower than the second preset value.
The multi-gun direct current charging pile insulation diagnosis device comprises a processor and a memory, wherein the detection unit 100, the first processing unit 200 and the second processing unit 300 are stored in the memory as program units, and the processor executes the program units stored in the memory to realize corresponding functions.
The processor comprises a kernel, and the kernel calls the corresponding program unit from the memory. One or more than one kernel can be set, and the purpose of accurately positioning the insulation fault vehicle is realized by adjusting kernel parameters.
The memory may include volatile memory in a computer readable medium, Random Access Memory (RAM) and/or nonvolatile memory such as Read Only Memory (ROM) or flash memory (flash RAM), and the memory includes at least one memory chip.
Optionally, when detecting that the insulation resistance of the negative electrode of the dc source to the ground is lower than the second preset value for the first time, the second processing unit 300 disconnects charging of the electric vehicle that has been connected to the multi-gun dc charging pile for the last time.
Optionally, as shown in fig. 6, the multi-gun dc charging pile insulation diagnosis apparatus further includes: and the third processing unit 400 is configured to determine that the dc source negative electrode-to-ground insulation impedance is faulty and disconnect charging of all electric vehicles if the dc source negative electrode-to-ground insulation impedance is still lower than the second preset value until charging of the last electric vehicle is disconnected.
Optionally, still referring to fig. 6, the multi-gun dc charging pile insulation diagnosis apparatus further includes: and a fourth processing unit 500, configured to detect whether the dc source positive electrode ground insulation impedance is lower than a third preset value, if so, determine that the dc source positive electrode ground insulation fault occurs, and disconnect charging of all electric vehicles.
Optionally, the detection unit 100 is specifically configured to detect the magnitude of the positive electrode-to-ground insulation resistance and the magnitude of the negative electrode-to-ground insulation resistance of the direct current source of the electric vehicle by using a bridge method.
The embodiments in the present description are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other. The device disclosed by the embodiment corresponds to the method disclosed by the embodiment, so that the description is simple, and the relevant points can be referred to the method part for description.
In this document, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, the use of the verb "comprise a" to define an element does not exclude the presence of another, identical element in a process, method, article, or apparatus that comprises the element.
Those of skill would further appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, computer software, or combinations of both, and that the various illustrative components and steps have been described above generally in terms of their functionality in order to clearly illustrate this interchangeability of hardware and software. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the embodiments. Thus, the present embodiments are not intended to be limited to the embodiments shown herein but are to be accorded the widest scope consistent with the principles and novel features disclosed herein.