CN110031753A - Quick charging system welding detection - Google Patents

Abstract

Present disclose provides " quick charging system welding detections ".A kind of DC quick charging system, including multiple contactors are to provide redundancy in the case where a contactor cannot be disconnected when being command by.A kind of method of the unintentionally high voltage situation prevented at charging port tests whether two contactors have been soldered.If detecting welding, another contactor is ordered to disconnect to prevent cell voltage from reaching the charging port.The method also regularly executes during vehicle operation other than immediately following executing after charging.

Description

Quick charging system welding detection

Technical field

This disclosure relates to the field of the charging system for electric vehicle.More particularly, this disclosure relates to which one kind prevents from filling The method of unintentionally high voltage situation at electric port.

Background technique

In order to reduce the consumption to fossil fuel, electric vehicle has been becoming increasingly popular.Some electric vehicles are not being transported It is charged using the energy in the fixation source from such as utility network to on-vehicle battery when row.In general, vehicle is only gone daily Several hours are sailed, the sufficient time is thus allowed to be recharged during other times.However, for cross-country driving and Speech, it is valuable for quickly capable of carrying out charging to vehicle.In order to meet this demand, some vehicles include quick charge system System, the quick charging system receive high DC electric current level from suitable fixed charging equipment.

Detailed description of the invention

Fig. 1 is the schematic diagram of electric vehicle quick charging system.

Fig. 2 is the mistake for checking the state of two contactors in the high-voltage switch of Fig. 1 during non-charging operations The flow chart of journey.

Fig. 3 to Fig. 6 is the mistake for the state of the contactor in charging complete in the high-voltage switch of individual inspiration Fig. 1 The flow chart of journey.

Specific embodiment

This document describes embodiment of the disclosure.However, it should be understood that the disclosed embodiments are only examples, and other Embodiment can be using different and substitution form.The drawings are not necessarily drawn to scale；Some features may be amplified or most Smallization is to show the details of particular elements.Therefore, specific structure and function detail disclosed herein should not necessarily be construed to restricted , but only as instructing those skilled in the art to use representative basis of the invention in various ways.Such as this field Ordinarily skilled artisan will understand that, the various features for showing and describing with reference to any one in attached drawing can with it is one or more other Feature shown in the drawings is combined to generate the embodiment for not being explicitly shown or describing.The combination of shown feature provides Representative embodiment for typical case.However, the various combinations and modification pair of the feature consistent with the introduction of the disclosure It may be desired for specific application or implementation.

Fig. 1 shows the quick charging system of vehicle.Vehicle includes DC main bus, and the DC main bus includes positive conductor 10 With negative conductor 12.One or more inverters 14 are connected to DC bus to drive the motor for vehicle propulsion.Battery pack includes Battery unit 16 and 18.Although fig 1 illustrate that two concatenated units, but the quantity of unit and arrangement can change.Battery Unit includes inside contactor 20,22,24 and 26.When unit is connected as shown in Figure 1, it is necessary to all contactors are closed, so that Battery is electrically connected to bus.One in these multiple inside contactors can be designated as main contactor, the main contactor by Controller is disconnected and is closed to realize and promote.If a contactor cannot disconnect when being command by, multiple disconnections are provided Redundancy.

DC bus is connected to charging port 30 via fast charge switch 32.Charging port 30, which may be also connected to, to be not shown Standard speed charging unit.Charge switch 32 just connects including what is be respectively opened or closed in response to the order from controller Connect device 34 and negative connector 36.Connector 34 and 36 must be all closed so that charging port 30 is electrically connected to DC bus.Work as vehicle When not charging, usual order connector 34 and 36 is disconnected so that charging port 30 and DC bus are electrically isolated.Charging station 38 is connection To the fixed power source of utility network or some other power supplys.Charging station 38 includes that the charging being inserted into Vehicular charging port 30 is inserted First 40.Charging port 30 may include locking device, and the locking device is activated by controller, to prevent during charging operations Disconnect charging plug.Charging port 30 can also include warning lamp or notify other devices of system mode to operator.

Under normal operation, contactor is fully disconnected or is closed completely.When being fully disconnected, no electric current flows through contact Device.When being closed completely, resistance is insignificant, and the voltage drop on contactor is insignificant.In some cases, it connects Tentaculum may be soldered.For example, enough heats may be generated if contactor is slightly disconnected in high current flow Carry out molten material and bridges gap.In case of such case, then contactor will not be fully disconnected when being command by.Different from complete The contactor of complete closure, soldered contactor have the resistance that can not ignore.Different from the contactor being fully disconnected, it is soldered Contactor permit high current and relatively low voltage drop.

If two contactors 34 and 36 are all soldered, during normal vehicle operation, close to the electricity of DC bus voltage Pressure will appear at charging port 30.A kind of method for avoiding such case is regularly to check each contactor, such as every Each contactor is checked at the end of a charging cycle.If one in contactor is soldered, quick charge spy can be disabled Sign, to substantially reduce a possibility that other contactors are soldered.But there are the feelings that two contactors may be all soldered Condition.For example, the two may be only if order disconnects the two to stop quick charge operation during quick charge operates Certain high current period is exposed in the case where slightly disconnecting.

Fig. 2 shows the processes whether two contactors 34 and 36 of test have all been soldered.It (is not filled in normal vehicle operation Electricity) during repeat this process.At 42, described process etc. is to be launched to be checked next time.This can be for example in response in Break signal and occur at regular intervals.There are several preconditions for this process.At 44, controller checks fast Whether the contactor 34 and 36 in fast charge switch 32 is command by disconnection.At 46, controller checks all internal cell contacts Whether device is all command by closure.At 48, controller checks whether charging plug is inserted into.If being unsatisfactory for these preconditions Any of, then control is back to 42 to wait next circulation.

At 50, controller is surveyed using the voltage sensor in fast charge switch on the charging port side of contactor Measure port voltage.Charging port conductor is connected to reference voltage, the reference resistance quilt by reference to resistance by voltage sensor It is chosen to electric current and is easy to measured but not excessive.If corresponding contactor is disconnected as order, electricity is not had Stream flows through reference resistance, and voltage will be equal to reference voltage.If corresponding contactor is soldered, the voltage measured is nearly The approximately equal to correspondence conductor voltage of DC bus.At 52, controller measures the voltage difference between the conductor 10 and 12 of DC bus.? At 54, the difference between these measured values is compared by controller with predetermined threshold.It is recommended that the threshold value of about 20V.If difference Greater than threshold value, then further movement is not taken.At least one of contactor is disconnected as order.

If difference is less than threshold value, controller obtains all soldered conclusion of two contactors.It takes several steps to Charging plug is prevented to be exposed to DC bus voltage.At 56, at least one of order internal cell contactor is disconnected.This is by DC Bus is isolated with cell voltage.At 58, in the controller setting prevent battery contactor in response to vehicle launch order and again The code of secondary closure.At 60, fault code is set in controller storage to indicate that vehicle is forbidden to maintenance personal Reason.Finally, making one or more warning lamps are shinny to break down to alert operator at 62.These lamps may include The status indicator lamp on status indicator lamp and Vehicular instrument panel on charging port.

Fig. 3 to Fig. 6 show for for example in charging complete individual inspiration contactor 34 and 36 method.Due in mistake Cheng Zhonghui order contactor changes state between disconnection and closure, therefore the process should not be executed in high current flow. As indicated at 70 in Fig. 3, there are several preconditions for this process.Firstly, closure inside battery should be ordered Contactor.Battery contactor order is indicated by symbol symbol BattChrgCnnct_B_Cmd.Secondly, should initially order closure Contactor 34 and 36.These orders are indicated by symbol DCPOS_RLY and DCNEG_RLY respectively.Finally, being mentioned by any charging plug The electric current of confession should be less than threshold value, such as 5 amperes.This electric current is indicated by symbol EVSEPresentCurrent.In these figures, Symbol VSENSE_DCPOS and VSENSE_DCNEG refer to the sensing voltage on the charging port side of corresponding contactor.Symbol HtrnAin_Uhi_Actl refers to the sensing voltage on the conductor of DC bus.

Although these embodiments are not intended to desired by description claim described above is exemplary embodiment All possible form.The word that word used in the description is to describe only and not limitation, and it will be understood that not departing from this Various changes can be carried out in the case where disclosed spirit and scope.As previously mentioned, the feature of various embodiments can be combined Come the other embodiments for forming possibility of the invention and being not explicitly described or illustrating.Although various embodiments may be described as The advantages of providing relative to one or more expected characteristics better than other embodiments or prior art implementation or more than them To be preferred, but those skilled in the art recognize, may be to one in order to realize desired total system attribute A or multiple feature or characteristic make compromise, this depends on concrete application and implementation.Therefore, be described as relative to one or Multiple characteristics are not as good as within the scope of this disclosure and right at other embodiments or the ideal embodiment of prior art implementation It may be desired for specific application.

Claims (1)

1. a kind of vehicle, the vehicle include:

Battery, the battery are used to selectively connect to DC bus；

Charging port, the charging port are used to selectively connect to the DC bus by charge switch, and the switch has two A contactor；

Controller, the controller are configured as when the vehicle is run,

Two contactors are ordered to disconnect, and

Welded condition is in response to the contactor and disconnects the battery and the DC bus.