Starting circuit of charger and charger

Abstract

The invention discloses a charger starting circuit and a charger, and relates to the power supply field, a step-down conversion module is used for carrying out step-down on an AC power supply, a first rectification module is used for converting the step-down AC power supply into a DC power supply, and when the first rectification module outputs the DC power supply, a first control module controls a first controllable switch to be closed; the direct current activates the charger control unit. Therefore, when the alternating current power supply is the power supply for the garage, the converted direct current can supply power to the charger control unit, and when the storage battery is lack of power, the alternating current power supply can be the power supply in the garage, and the direct current electric energy converted from the alternating current can activate the charger control unit and the charger to charge the storage battery lack of power. And the storage battery does not need to be charged by using a mobile charger or another train, so that the cost of charging equipment is reduced, and the process steps are relatively simple.

Description

Technical Field

[0001] The present invention relates to the field of power supply, and in particular to a starting circuit of a charger and a charger. Background Art

[0002] Batteries and chargers are important components of the auxiliary power supply system of rail transit vehicles. When rail transit vehicles are not connected to the overhead line and there is no power supply from the storage, the battery can supply power to the DC load of the entire vehicle. However, the battery can only work for a limited time. If the battery is low, the DC-controlled bow raising device cannot raise the bow, and the overhead line cannot provide three-phase AC power to the load. Therefore, the on-board converter cannot provide three-phase AC power to the charger, which in turn causes the charger to be unable to provide DC power to the load of the entire vehicle and charge the low-power battery.

[0003] Based on the above situation, in the prior art, when the battery is low on power, it is necessary to use a mobile charger or another train to charge the low-power battery. However, this charging method will lead to problems such as complicated operating procedures and high cost of the mobile charger. Summary of the invention

[0004] The object of the present invention is to provide a starting circuit for a charger and a charger. When the battery is low on power, the AC power supply can be the power supply inside the depot, and the power supply inside the depot powers the charger. There is no need for an additional mobile charger or the use of another train to power the battery. Therefore, the cost of the charging equipment can be reduced and the operation process steps are simple.

[0005] In order to solve the above technical problems, the present invention provides a starting circuit of a charger, comprising a step-down conversion module, a first rectifier module, a first control module and a first controllable switch;

[0006] The input end of the step-down conversion module is used to connect to the AC power supply and to step down the AC power output by the AC power supply;

[0007] The input end of the first rectifier module is connected to the output end of the step-down conversion module, and is used to convert the stepped-down AC power into DC power;

[0008] A first end of the first controllable switch is connected to the output end of the first rectifier module, and a second end is connected to the power supply end of the charger control unit;

[0009] The first control module is connected to the output end of the first rectifier module, and is used to control the first controllable switch to be closed when the first rectifier module outputs direct current, and to control the first controllable switch to be opened when the first rectifier module does not output direct current.

[0010] Optionally, the first controllable switch is a contactor;

[0011] A first end of the coil of the contactor is connected to the positive end of the output end of the first rectifier module, and a second end of the coil of the contactor is connected to the second end of the first current limiting resistor;

[0012] A first end of the contact of the contactor is connected to the output end of the first rectifier module, and a second end is connected to the power supply end of the charger control unit.

[0013] Optionally, the first control module includes a first current limiting resistor;

[0014] The first end of the first current limiting resistor is connected to the negative end of the output end of the first rectifier module, and the second end is connected to the second end of the first controllable switch.

[0015] Optionally, the power supply end of the charger control unit is also connected to the output end of the converter and the output end of the battery respectively;

[0016] The startup circuit also includes:

[0017] A second controllable switch, the second controllable switch is arranged on a connection loop between the first current limiting resistor and the coil of the contactor;

[0018] A voltage detection circuit, wherein an input end of the voltage detection circuit is connected to a power supply end of the charger control unit, and an output end of the voltage detection circuit is connected to a second control module, and is used to detect a voltage connected to the power supply end of the charger control unit;

[0019] The second control module, the control end of the second control module is connected to the control end of the second controllable switch, and is used to control the second controllable switch to be disconnected when there is voltage at the power supply end of the charger control unit, and to control the second controllable switch to be closed when there is no voltage at the power supply end of the charger control unit.

[0020] Optionally, it also includes:

[0021] a first diode, wherein an anode of the first diode is connected to a positive output terminal of the converter and a positive output terminal of the battery, and a cathode of the first diode is connected to a power supply terminal of a charger control unit;

[0022] The second diode has an anode connected to the output end of the contact of the contactor, and a cathode connected to the power supply end of the charger control unit.

[0023] Optionally, it also includes:

[0024] A filter module, wherein the input end of the filter module is connected to an AC power supply, and the output end is connected to a step-down conversion module.

[0025] Optionally, it further includes a first circuit breaker and / or a second circuit breaker;

[0026] The first end of the first circuit breaker is connected to the output end of the AC power supply, and the second end is connected to the input end of the filter module, and is used to disconnect when the current flowing through the first circuit breaker is greater than the first current preset value;

[0027] The first end of the second circuit breaker is connected to the output end of the filter module, and the second end is connected to the input end of the step-down conversion module, and is used to disconnect when the current flowing through the second circuit breaker is greater than the first current preset value.

[0028] Optionally, the first circuit breaker further includes:

[0029] Auxiliary contact, two ends of the auxiliary contact are connected to the state monitoring circuit, and the auxiliary contact has the same switch state as the first circuit breaker;

[0030] The status monitoring circuit is used to issue a status warning when the auxiliary contact changes from closed to open.

[0031] In order to solve the above technical problems, the present invention further provides a charger, comprising the charger starting circuit as described above, and also comprising a controllable switch module and a second rectifier module, and a charger control unit;

[0032] The first end of the controllable switch module is connected to the AC power supply, the control end is connected to the output end of the charger control unit, and the second end is connected to the input end of the second rectifier module;

[0033] The output end of the second rectifier module is connected to the power supply end of the battery.

[0034] Optionally, the controllable switch module includes:

[0035] a third controllable switch, wherein a first end of the third controllable switch is connected to an AC power source, a second end of the third controllable switch is connected to a first end of a second current limiting resistor, and a control end of the third controllable switch is connected to an output end of a charger control unit;

[0036] A second current limiting resistor, wherein a second end of the second current limiting resistor is connected to an input end of the second rectifier module;

[0037] A fourth controllable switch, wherein a first end of the fourth controllable switch is connected to an AC power source, a second end of the fourth controllable switch is connected to an input end of the second rectifier module, and a control end of the fourth controllable switch is connected to an output end of the charger control unit.

[0038] The present invention provides a charger starting circuit and charger, including a step-down conversion module, a first rectifier module, a first control module and a first controllable switch. First, the step-down conversion module steps down the AC power, and the first rectifier module steps down and rectifies the AC power supply into DC power. When the first rectifier module outputs DC power, the first control module controls the first controllable switch to close, and the DC power can power the charger control unit. When the battery is low on power, the AC power supply can be a power supply in the depot, which can directly activate the charger control unit, and the charger charges the low-power battery. There is no need to use a mobile charger or use another train to charge the battery, which reduces the cost of the charging equipment and simplifies the process steps. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the prior art and the drawings required for use in the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0040] Figure 1 A schematic diagram of the structure of a starting circuit of a charger provided by the present invention;

[0041] Figure 2 A schematic diagram of the specific structure of a starting circuit of a charger provided by the present invention. DETAILED DESCRIPTION

[0042] The present invention provides a starting circuit for a charger and a charger. When a battery is low on power, an AC power source can be an internal power source to directly activate a charger control unit, and the charger charges the low-power battery. There is no need to use a mobile charger or use another train to charge the battery, thereby reducing the cost of the charging equipment and simplifying the process steps.

[0043] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0044] Please refer to Figure 1 , Figure 1 A schematic structural diagram of a starting circuit of a charger provided by the present invention.

[0045] The starting circuit of the charger includes a step-down conversion module 1, a first rectifier module 2, a first control module 3 and a first controllable switch 4;

[0046] The input end of the step-down conversion module 1 is used to connect to the AC power supply, and is used to step down the AC power output by the AC power supply;

[0047] The input end of the first rectifier module 2 is connected to the output end of the step-down conversion module 1, and is used to convert the stepped-down AC power into DC power;

[0048] A first end of the first controllable switch 4 is connected to the output end of the first rectifier module 2, and a second end is connected to the power supply end of the charger control unit 5;

[0049] The first control module 3 is connected to the output end of the first rectifier module 2, and is used to control the first controllable switch 4 to be closed when the first rectifier module 2 outputs DC power, and to control the first controllable switch 4 to be opened when the first rectifier module 2 does not output DC power.

[0050] It is understandable that when the vehicle is connected to the overhead line through the pantograph, the electricity on the overhead line will power the DC load on the vehicle (including the charger control unit 5 and the pantograph control module that controls the pantograph raising) through the converter. When the pantograph of the vehicle is not connected to the overhead line, the battery will power the DC load of the vehicle. If the battery voltage is lower than the set threshold, the vehicle will be powered off, the DC load of the vehicle will stop working, and the battery will be in a low-power state. Since the pantograph control module loses power, the vehicle cannot raise the pantograph to transmit electricity, and the overhead line cannot provide three-phase AC power to the charger through the on-board converter, which results in the charger being unable to provide DC power to the entire vehicle load and unable to charge the battery.

[0051] For the charger control unit 5, when the pantograph of the vehicle is connected to the overhead line, the power for activating and maintaining the charger control unit 5 of the charger comes from the overhead line; when the pantograph of the vehicle is not connected to the overhead line and the battery is fully charged, the power for activating and maintaining the charger control unit 5 of the charger comes from the battery. In the present application, when the pantograph of the vehicle is connected to the overhead line and the battery is low on power, the power for activating and maintaining the charger control unit 5 of the charger comes from the starting circuit of the charger.

[0052] In this application, a step-down conversion module 1 and a first rectifier module 2 are set in the starting circuit of the charger, and the three-phase AC power of U, V, and W of the AC power supply can be output to the auxiliary power supply bus. The first rectifier module 2 rectifies the AC power on the auxiliary power supply bus, and the rectified DC power is used to activate the charger control unit 5. After the charger control unit 5 is activated, the charger can charge the depleted battery. Among them, the AC power supply here can be a warehouse power supply, that is, a power supply in the station.

[0053] Specifically, when the voltage of the battery is lower than the set threshold, the battery is depleted. When the AC power supply is the power supply inside the warehouse, the warehouse socket is used to input three-phase AC power to the vehicle from the outside to provide three-phase AC power for the auxiliary power supply bus. The step-down conversion module 1 draws power from the auxiliary power supply bus to step down the three-phase AC power. The first rectifier module 2 at the rear end of the step-down conversion module 1 rectifies the stepped-down three-phase AC power and outputs DC power. The first control module 3 controls the first controllable switch 4 to close when the first rectifier module 2 outputs DC power, and the DC power supplies the charger control unit 5.

[0054] Specifically, the charger can obtain a 380V three-phase AC power supply from the auxiliary power supply bus, step down and rectify the 380V three-phase AC power supply into a 110V DC power, and the 110V DC power controls and activates the charger control unit 5.

[0055] In the present application, the step-down conversion module 1 is specifically used to convert a star-shaped three-phase AC power supply into a triangular AC power supply, and utilizes the characteristic that the third harmonic of the triangle is in phase to make the third harmonic current form a circulation current on the triangle side to circulate, so as to ensure that the potential is not distorted, thereby reducing the third harmonic of the first rectifier module 2.

[0056] It can be seen that when the battery is low on power, the AC power supply can be the power supply inside the depot, and the AC power supply can be stepped down and rectified to obtain DC power. The DC power can activate the charger control unit 5, and then the charger charges the low-power battery. There is no need to use a mobile charger or use another train to charge the battery, so the cost of the charging equipment is reduced and the process steps are relatively simple.

[0057] Based on the above embodiments:

[0058] Please refer to Figure 2 , Figure 2 A schematic diagram of the specific structure of a starting circuit of a charger provided by the present invention;

[0059] As an optional embodiment, the first controllable switch 4 is a contactor K1;

[0060] A first end of the coil of the contactor K1 is connected to the positive output end of the first rectifier module 2, and a second end of the coil of the contactor K1 is connected to the second end of the first current limiting resistor Rk1;

[0061] A first end of the contact of the contactor K1 is connected to the output end of the first rectifier module 2 , and a second end is connected to the power supply end of the charger control unit 5 .

[0062] Specifically, when the coil of the contactor K1 is energized, the main contacts of the contactor K1 are closed, the circuit between the first rectifier module 2 and the charger control unit 5 is connected, and the first rectifier module 2 provides direct current to the charger control unit 5; when the coil of the contactor K1 is not energized, the main contacts of the contactor K1 are disconnected, the circuit between the first rectifier module 2 and the charger control unit 5 is disconnected, and the direct current at the output end of the first rectifier module 2 stops being output to the charger control unit 5.

[0063] It can be seen that in the present application, a contactor K1 is arranged between the output end of the first rectifier module 2 and the charger control unit 5, and the AC power supply is used to supply or cut off the power to the charger control unit 5 by controlling the contactor K1. In addition, the contactor K1 also has the advantages of low noise and fast and reliable disconnection.

[0064] As an optional embodiment, the first control module 3 includes a first current limiting resistor RK1;

[0065] A first end of the first current limiting resistor Rk1 is connected to the negative end of the output of the first rectifier module 2 , and a second end of the first current limiting resistor Rk1 is connected to the second end of the first controllable switch 4 .

[0066] Specifically, the first current limiting resistor Rk1, the coil of the contactor K1, and the output end of the first rectifier module 2 form a loop. When the first rectifier module 2 outputs direct current, the coil of the contactor K1 is energized, and the first controllable switch 4 is closed to output direct current. The first current limiting resistor Rk1 here is also used to protect the loop to prevent excessive current flowing through the coil of the contactor K1.

[0067] As an optional embodiment, the power supply end of the charger control unit 5 is also connected to the output end of the converter and the output end of the battery respectively;

[0068] The startup circuit also includes:

[0069] A second controllable switch K2, which is arranged on a connection loop between the first current limiting resistor Rk1 and the coil of the contactor K1;

[0070] A voltage detection circuit 6, wherein the input end of the voltage detection circuit 6 is connected to the power supply end of the charger control unit 5, and the output end of the voltage detection circuit 6 is connected to the second control module 7, and is used to detect the voltage connected to the power supply end of the charger control unit 5;

[0071] The second control module 7, the control end of the second control module 7 is connected to the control end of the second controllable switch K2, and is used to control the second controllable switch K2 to be disconnected when there is voltage at the power supply end of the charger control unit 5, and to control the second controllable switch K2 to be closed when there is no voltage at the power supply end of the charger control unit 5.

[0072] First of all, it should be explained that the input end of the converter is connected to the pantograph so as to convert the three-phase alternating current received by the pantograph.

[0073] In the present application, in order to prevent the AC power supply, the contact network and the battery from supplying power to the charger control unit 5 at the same time and damaging the charger control unit 5, a second controllable switch K2, a voltage detection circuit 6 and a second control module 7 are provided. Specifically, when the contact network provides three-phase AC power and / or the battery is powered, the voltage detection circuit 6 detects that there is voltage at the power supply end of the charger control unit 5, and the charger control unit 5 works normally. At this time, the second control module 7 controls the second controllable switch K2 to disconnect, and no emergency start circuit is required. When there is no contact network to provide three-phase AC power and the battery is low on power, the voltage detection circuit 6 will detect that there is no voltage at the power supply end of the charger control unit 5, and the second control module 7 controls the second controllable switch K2 to close, and the emergency start circuit is started at this time. In actual applications, the second controllable switch K2 is a passive normally closed contact, which is usually in a closed state.

[0074] It should be noted that, in practical applications, the second controllable switch K2 , the second control module 7 and the voltage detection circuit 6 can be integrated into the charger control unit 5 .

[0075] The voltage detection circuit 6 provided by the present invention can reliably detect whether there is voltage at the power supply end of the charger control unit 5, and the circuit structure is simple.

[0076] As an optional embodiment, it also includes:

[0077] A first diode VD1, wherein the anode of the first diode VD1 is connected to the positive output terminal of the converter and the positive output terminal of the battery, and the cathode of the first diode VD1 is connected to the power supply terminal of the charger control unit 5;

[0078] The second diode VD2 has an anode connected to the output end of the contact of the contactor K1 and a cathode connected to the power supply end of the charger control unit 5 .

[0079] It should be noted that, considering that the power supply end of the charger control unit 5 is respectively connected to the output end of the inverter, the output end of the battery and the output end of the starting circuit, in order to avoid the power supply current from being backflowed to the output end of the inverter or the output end of the battery when the output end of the starting circuit is powered, or the power supply current from the output end of the inverter or the output end of the battery is backflowed to the output end of the starting circuit, a first diode VD1 and a second diode VD2 are provided in the present application, thereby effectively preventing the current backflow between the two power supply branches and improving the power supply safety.

[0080] As an optional embodiment, it also includes:

[0081] A filter module, the input end of the filter module is connected to the AC power supply, and the output end is connected to the step-down conversion module 1.

[0082] In this application, considering that there will be noise in the AC power supply in actual applications, an EMC (Electromagnetic Compatibility) filter module is configured at the output end of the AC power supply. The EMC filter module includes an EMI (Electromagnetic Interference) filter device and a three-phase filter inductor. The EMI filter device can reduce the radiation level of the charger and improve the EMC anti-interference performance of the charger. The three-phase filter inductor can improve the working efficiency of the charger.

[0083] It can be seen that the present application can obtain a relatively pure AC power supply by setting up the filter module and improve the anti-interference performance of the charger. Subsequently, the step-down conversion module 1 and the first rectifier module 2 can output pure DC power to activate the charger control unit 5.

[0084] As an optional embodiment, it further includes a first circuit breaker QF1 and / or a second circuit breaker QF2;

[0085] A first end of the first circuit breaker QF1 is connected to the output end of the AC power supply, and a second end is connected to the input end of the filter module, and is used to disconnect when the current flowing through the first circuit breaker QF1 is greater than a first current preset value;

[0086] The first end of the second circuit breaker QF2 is connected to the output end of the filter module, and the second end is connected to the input end of the step-down conversion module 1, and is used to disconnect when the current flowing through the second circuit breaker QF2 is greater than the second current preset value.

[0087] Taking into account that when an AC power source, such as an in-store power source, supplies power to a charger, there may be a problem of power supply current fluctuation, in order to ensure the power supply safety of the starting circuit for the charger control unit 5, in this application, a first circuit breaker QF1 is provided at the output end of the AC power source, and a second circuit breaker QF2 is provided between the filter module and the step-down conversion module 1, thereby realizing power supply protection for each module in the starting circuit and the charger control unit 5, and improving power supply reliability.

[0088] In addition, the circuit breaker will not be seriously worn after opening and closing within the specified electrical life and is safe and reliable. Secondly, the circuit breaker is not affected by external environmental conditions and has strong earthquake resistance. As an optional embodiment, the first circuit breaker QF1 also includes:

[0089] Auxiliary contact, the two ends of the auxiliary contact at points 13 and 14 are connected to the state monitoring circuit 9, and the auxiliary contact has the same switch state as the first circuit breaker QF1;

[0090] The state monitoring circuit 9 is used to issue a state warning when the auxiliary contact changes from closed to open.

[0091] Specifically, when the current flowing through the first circuit breaker QF1 is too large, the first circuit breaker QF1 is disconnected, and the auxiliary contact of the first circuit breaker QF1 is also disconnected accordingly. Since the auxiliary contact is connected to the status monitoring circuit 9, when the auxiliary contact changes from closed to open, it will report to the train TCMS (Train Control and Management System, locomotive microcomputer control and monitoring system) system to prompt a fault.

[0092] The present invention further provides a charger, comprising the charger starting circuit as described above, and further comprising a controllable switch module and a second rectifier module 8, and a charger control unit 5;

[0093] The first end of the controllable switch module is connected to the AC power supply, the control end is connected to the output end of the charger control unit 5, and the second end is connected to the input end of the second rectifier module 8;

[0094] The output end of the second rectifier module 8 is connected to the power supply end of the battery.

[0095] It is understandable that when the start-up circuit is connected to the AC power supply, the start-up circuit activates the charger control unit 5, the charger control unit 5 controls the controllable switch module to close, and the second rectifier module 8 rectifies the AC power supply into DC power to charge the depleted battery. Specifically, when controlling the second rectifier module 8, a phase-shifted full-bridge soft switch control technology can be used to effectively improve the output efficiency of the charger.

[0096] It should also be noted that the first end of the first circuit breaker QF1 in the starting circuit of the charger is also directly or indirectly connected to the pantograph through the step-down module, so that the contact network can charge the battery through the controllable switch module and the second rectifier module 8.

[0097] As an optional embodiment, the controllable switch module includes:

[0098] A third controllable switch KM12, wherein a first end of the third controllable switch KM12 is connected to an AC power source, a second end of the third controllable switch KM12 is connected to a first end of a second current limiting resistor Rk, and a control end of the third controllable switch KM12 is connected to an output end of the charger control unit 5;

[0099] A second current limiting resistor Rk, wherein a second end of the second current limiting resistor Rk is connected to an input end of the second rectifier module 8;

[0100] A fourth controllable switch KM11 , a first end of the fourth controllable switch KM11 is connected to the AC power supply, a second end is connected to the input end of the second rectifier module 8 , and a control end is connected to the output end of the charger control unit 5 .

[0101] It should be noted that a voltage-stabilizing capacitor is usually provided in the second rectifier module 8. When the AC power supply charges the battery through the controllable switch module and the second rectifier module 8, a large surge current is easily generated in the charging circuit between the AC power supply and the battery due to the presence of the voltage-stabilizing capacitor.

[0102] In order to solve this problem, in the present application, the controllable switch module includes a third controllable switch KM12, a second current limiting resistor Rk and a fourth controllable switch KM11. Based on this structure, when the AC power supply is supplying power to the battery, the charger control unit 5 first controls the third controllable switch KM12 to close and controls the fourth controllable switch KM11 to open. At this time, the power supply current passes through the second current limiting resistor Rk, thereby reducing the charging current of the battery and realizing the pre-charging of the voltage-stabilizing capacitor. After the pre-charging of the voltage-stabilizing capacitor is completed, the charger control unit 5 controls the third controllable switch KM12 to open and controls the fourth controllable switch KM11 to close. At this time, the battery is charged through the closed fourth controllable switch KM11.

[0103] It can be seen that through this method, the charging current of the battery can be kept stable during the entire charging process, and the charging efficiency of the battery can also be guaranteed.

[0104] It should also be noted that the three-phase filter inductor in the starting circuit can also prevent sudden changes in the charging circuit when the battery is charging, further improving the power supply reliability.

[0105] It should be noted that, in this specification, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the statement "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device including the element.

[0106] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A starting circuit for a charger, characterized in that: It includes a step-down conversion module, a first rectification module, a first control module and a first controllable switch; The input end of the step-down conversion module is used to be connected to an AC power source, and is used to step down the AC power output by the AC power source; The input end of the first rectifier module is connected to the output end of the step-down conversion module, and is used to convert the stepped-down alternating current into direct current; A first end of the first controllable switch is connected to an output end of the first rectifier module, and a second end is connected to a power supply end of the charger control unit; The first control module is connected to the output end of the first rectifier module, and is used to control the first controllable switch to be closed when the first rectifier module outputs the direct current, and to control the first controllable switch to be opened when the first rectifier module does not output the direct current.

2. The starting circuit of the charger according to claim 1, characterized in that: The first controllable switch is a contactor; A first end of the coil of the contactor is connected to the positive output end of the first rectifier module, and a second end of the coil of the contactor is connected to the second end of the first current limiting resistor; The first end of the contact of the contactor is connected to the output end of the first rectifier module, and the second end is connected to the power supply end of the charger control unit.

3. The starting circuit of the charger according to claim 2, characterized in that: The first control module includes a first current limiting resistor; A first end of the first current limiting resistor is connected to a negative end of an output end of the first rectifier module, and a second end of the first current limiting resistor is connected to a second end of the first controllable switch.

4. The starting circuit of the charger according to claim 3, characterized in that: The power supply end of the charger control unit is also connected to the output end of the converter and the output end of the battery respectively; The startup circuit also includes: a second controllable switch, the second controllable switch being arranged on a connection loop between the first current limiting resistor and the coil of the contactor; A voltage detection circuit, wherein the input end of the voltage detection circuit is connected to the power supply end of the charger control unit, and the output end is connected to the second control module, and is used to detect the voltage connected to the power supply end of the charger control unit; The second control module, the control end of the second control module is connected to the control end of the second controllable switch, and is used to control the second controllable switch to be disconnected when there is voltage at the power supply end of the charger control unit, and to control the second controllable switch to be closed when there is no voltage at the power supply end of the charger control unit.

5. The starting circuit of the charger as claimed in claim 4, characterized in that: Also includes: a first diode, wherein an anode of the first diode is connected to a positive output terminal of the converter and a positive output terminal of the battery, and a cathode of the first diode is connected to a power supply terminal of the charger control unit; A second diode, wherein an anode of the second diode is connected to an output end of the contact of the contactor, and a cathode of the second diode is connected to a power supply end of the charger control unit.

6. The starting circuit of the charger according to claim 1, characterized in that: Also includes: A filter module, wherein an input end of the filter module is connected to the AC power supply, and an output end of the filter module is connected to the step-down conversion module.

7. The starting circuit of the charger according to claim 1, characterized in that: Also includes a first circuit breaker and / or, a second circuit breaker; The first end of the first circuit breaker is connected to the output end of the AC power supply, and the second end is connected to the input end of the filter module, and is used to disconnect when the current flowing through the first circuit breaker is greater than a first current preset value; The first end of the second circuit breaker is connected to the output end of the filter module, and the second end is connected to the input end of the buck conversion module, and is used for disconnecting when the current flowing through the second circuit breaker is greater than a second current preset value.

8. The starting circuit of the charger according to claim 7, characterized in that: The first circuit breaker further comprises: An auxiliary contact, two ends of which are connected to a state monitoring circuit, and the auxiliary contact has the same switch state as the first circuit breaker; The state monitoring circuit is used to issue a state warning when the auxiliary contact changes from closed to open.

9. A charger, characterized in that: A charger starting circuit comprising the charger according to any one of claims 1 to 8, further comprising a controllable switch module and a second rectifier module, and a charger control unit; The first end of the controllable switch module is connected to the AC power supply, the control end is connected to the output end of the charger control unit, and the second end is connected to the input end of the second rectifier module; The output end of the second rectifier module is connected to the power supply end of the battery.

10. The charger according to claim 9, characterized in that: The controllable switch module comprises: a third controllable switch, wherein a first end of the third controllable switch is connected to the AC power supply, a second end of the third controllable switch is connected to a first end of a second current limiting resistor, and a control end of the third controllable switch is connected to an output end of the charger control unit; The second current limiting resistor, wherein the second end of the second current limiting resistor is connected to the input end of the second rectifier module; A fourth controllable switch, wherein a first end of the fourth controllable switch is connected to the AC power supply, a second end is connected to the input end of the second rectifier module, and a control end is connected to the output end of the charger control unit.

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