CN218524798U

CN218524798U - Detection system for direct current charging contactor

Info

Publication number: CN218524798U
Application number: CN202122978771.6U
Authority: CN
Inventors: 冒志敏; 郭长春; 吕晶; 段志强; 俞君; 吴飞进
Original assignee: Guochong Charging Technology Jiangsu Co ltd
Current assignee: Guochong Charging Technology Jiangsu Co ltd
Priority date: 2021-11-30
Filing date: 2021-11-30
Publication date: 2023-02-24
Anticipated expiration: 2031-11-30

Abstract

The utility model provides a charging direct current contactor detection system, which is simple in operation, can conveniently complete the detection of the reliability and the electrical service life of the charging direct current contactor, can shorten the detection time, reduce the complicated operation process and reduce the labor cost; the utility model provides a fill direct current contactor detecting system, its includes the direct contactor KM1 that detects and detect, and it still includes switch QS1, QS2, QS3, contactor KM2, relay K1, KA2, switching power supply SP1, display LCD, pilot lamp LE1, main control module.

Description

Fill direct current contactor detecting system

Technical Field

The utility model belongs to the technical field of new forms of energy electric automobile charging technology and specifically relates to be applied to and fill direct current contactor fail safe nature testing arrangement in the electric pile product, specifically be a fill direct current contactor detecting system.

Background

The development speed of new energy automobiles is witnessed in recent years, and the new energy automobiles become one of the industries of China and the leading world at present. For new energy vehicles and charging facilities, the market capacity of a dc contactor, which is one of the key electrical components, is also expanded. The direct current contactor in the charging pile is different from a common industrial contactor product, has the basic characteristics of high voltage and large current, and the application environment conditions need to simultaneously meet the basic conditions of wide temperature range, high protection grade, high vibration resistance and the like, so that the adaptability requirement on the contactor for the electric automobile is more strict.

When the direct current contactor is applied to a charging pile (machine), the direct current contactor is used for a direct current charging pile, a direct current output side of a charging station or an output side of a vehicle-mounted charger, and when the direct current contactor is closed, the direct current contactor plays a role in communicating the charging pile with an automobile; when the disconnection, keep apart and fill electric pile and outside connection, play the safety protection effect. When the direct current contactor is applied to an electric automobile, the direct current contactor is arranged between a battery system and an inverter of the electric automobile, plays a role in isolation after the battery system stops running, plays a role in connection when the battery system runs, and can safely separate an energy storage system from an electric system of the automobile when the automobile is closed or has a fault so as to play a role in breaking a circuit; and the direct current contactor can also be used as an electricity utilization control device in other auxiliary loops.

In summary, it is required that the dc contactor has high reliability and electrical life, which are the most critical elements for measuring the electric vehicle and the charging pile, and for this reason, it is necessary to perform related reliability detection on the dc contactor, but there is no matched testing device/system currently, and most of the detections on the dc contactor are performed by visual inspection, and if a comprehensive test needs to be completed, much labor and time are wasted, and some detection labors cannot be tested.

Disclosure of Invention

To the above problem, the utility model provides a fill direct current contactor detecting system, its easy operation can conveniently accomplish to filling direct current contactor reliability and electric life's detection, can shorten check-out time, reduces loaded down with trivial details operation process, reduces the cost of labor.

The technical scheme is as follows: the utility model provides a fill direct current contactor detecting system, its includes the direct current contactor KM1 that waits to detect, its characterized in that: it still includes switch QS1, QS2, QS3, contactor KM2, relay K1, KA2, switching power supply SP1, display LCD, pilot lamp LE1, main control module, three phase current source is through connecting behind the relay K1 with switching power supply SP1 is connected, display LCD, pilot lamp LE1 all connect in main control module, switching power supply SP 1's-24V output with display LCD, main control module, relay KA 2's normally open contact KA 2-1's one end homogeneous phase is connected, switching power supply SP 1's 24V output with switch QS1, QS2, QS 3's one end homogeneous phase is connected, switch QS 3's the other end with display LCD, main control module homogeneous phase are connected, relay KA 2's the other end with the one end of normally closed contact KA1-2, the one end of direct contactor KM1 coil connect, the one end of normally closed contact QS 1-2's normal open contact KA 1-2's one end, direct contactor KM2 coil connect, the other end of relay KA1-2 normal closed contact KA 1-2's normal open contact KA 1-2's one end direct contactor, relay KA 1-to the other end direct contactor KM1 coil connect the other end of relay KA 1-phase is connected with the other end of relay KA 1-phase current contactor.

It is further characterized in that:

the direct current contactor is characterized by further comprising direct current terminal rows ZD1, ZD2 and a direct current power supply, wherein the direct current power supply adopts a programmable direct current power supply of a model 2231A-30-3, the direct current power supply is connected to two ends of a main contact of the direct contactor KM1, the direct current terminal row ZD1 is connected to a connection point between one end of a normally closed contact KA1-1 of the relay KA1 and the other end of a switch QS1, and the direct current terminal row ZD2 is connected to a connection point between the other end of a normally open contact KA2-1 of the relay KA2 and one end of a normally closed contact KA1-2 of the relay KA 1;

a resistive load circuit is connected between the main contacts of the direct contactor KM1 and the contactor KM2, the resistive load circuit comprises a load, a charging power supply module and a BMS power supply which are sequentially connected, the load is connected with one end of the main contact of the contactor KM2, the output end of the BMS power supply is connected with one end of the main contact of the direct contactor KM1, and the other end of the main contact of the direct contactor KM1 is connected with the other end of the main contact of the contactor KM 2;

the main control module comprises a control board, and a control circuit, a power supply circuit, a fault test circuit, a feedback detection circuit and a screen communication circuit are arranged on the control board; the control circuit comprises a controller U1, a resistor R1 and a light emitting diode LED1; the controller U1 adopts a model N11HXB singlechip chip; the power supply circuit comprises a switching power supply U2, a voltage stabilizer U3, a resistor R2, an inductor L1, a diode D1, a light-emitting diode LED2, capacitors C1-C4 and a connector JX1; the fault testing circuit comprises relays KA3 and KA4, a connector JX2, diodes D2 and D3, triodes Q1 and Q2 and resistors R3-R6; the feedback detection circuit comprises resistors R7 and R8, an optocoupler U4, a light emitting diode LED3 and a connector JX3; the screen communication circuit comprises resistors R9-R11, a connector JX4, TVS tubes TVS 1-TVS 3, a transceiver U5, an inductor L2, capacitors C5, C6 and C7; the transceiver U5 adopts a type TD301D485H transceiver chip;

the controller U1 is divided into controllers U1A and U1B,

pins

33 and 35 of the controller U1A are connected with a power supply of 3.3V,

pins

34 and 36 of the controller U1A are connected with each other and then grounded, pins 88 and 90 of the controller U1B are connected with each other and then grounded,

pins

60, 73 and 89 of the controller U1B are grounded, and pin 85 of the controller U1B is sequentially connected with the resistor R1 and the light emitting diode LED1 and then grounded;

a pin 1 of the switching power supply U2 is connected with a power supply 24V, a pin 3 of the switching power supply U2 is grounded, a pin 2 of the switching power supply U2 is connected with a negative electrode of the diode D1 and one end of the inductor L1, a pin 4 of the switching power supply U2 is connected with the other end of the inductor L1, one ends of the capacitors C1 and C2 and a pin 3 of the voltage stabilizer U3 and then connected with a power supply 5V, a pin 2 of the voltage stabilizer U3 is connected with a pin 4 of the voltage stabilizer U3, one ends of the capacitors C3 and C4 and a resistor R2 and then connected with a power supply 3.3V, the other end of the resistor R2 is connected with a negative electrode of the light emitting diode LED2, and a pin 5 of the switching power supply U2 is connected with a pin 1 of the voltage stabilizer U3, an anode of the diode D1, a negative electrode of the light emitting diode LED2, and the other ends of the capacitors C1, C2, C3 and C4 and then grounded;

pins

1 and 2 of the connector JX1 are connected and then grounded, and

pins

3 and 4 of the connector JX1 are connected and then connected with the power supply 24V;

one end of the relay KA3 coil is connected with the negative electrode of the diode D2 and then connected with the power supply 5V, the other end of the relay KA3 coil is connected with the positive electrode of the diode D2 and the collector of the triode Q1, one end of the relay KA3 main contact is connected with one end of the relay KA4 main contact, the other end of the relay KA3 main contact is connected with the 4 pin of the connector JX2, the other end of the relay KA4 main contact is connected with the 3 pin of the connector JX2, one end of the relay KA4 coil is connected with the negative electrode of the diode D3 and then connected with the power supply 5V, the other end of the relay KA4 coil is connected with the positive electrode of the diode D3 and the collector of the triode Q2, the base electrode of the triode Q1 is connected with one end of the resistor R3, the other end of the resistor R3 and the 26 pin of the controller U1A are connected, the other end of the resistor R4 is connected with the emitter of the triode Q1 and then grounded, the base electrode of the triode Q2 is connected with one end of the resistor R5, the other end of the resistor R5 is connected with one end of the resistor R6, the emitter of the resistor R6 and the emitter of the resistor R6 of the triode Q6 are connected with the emitter of the triode Q6;

the positive electrode of the light emitting diode LED3 is connected to a pin 6 of the connector JX3, the negative electrode of the light emitting diode LED3 is connected to a pin 1 of the optocoupler U4, a pin 2 of the optocoupler U4 is connected with the resistor R8 and then grounded, a pin 3 of the optocoupler U4 is grounded, a pin 4 of the optocoupler U4 is connected with one end of the resistor R7 and a pin 48 of the controller U1B, and the other end of the resistor R7 is connected with a power supply of 3.3V;

the one end of electric capacity C5, C6 with the one end of inductance L2 all links to each other the back and connects in power 3.3V, the other end of inductance L2 with the one end of electric capacity C7, 1 foot homogeneous phase of transceiver U5 are connected, the other end of electric capacity C5, C6, C7 with 2 feet of transceiver U5 link to each other the back ground connection, 3 feet of transceiver U5 connect after resistance R9 connects in 74 feet of controller U1B, 4 feet of transceiver U5 connect after resistance R10 connect in 75 feet of controller U1B, 5 feet of transceiver U5 connect 70 feet of controller U1B, 10 feet of transceiver U5 with 1 foot of connector JX4 links to each other the back ground connection, 9 feet of transceiver U5 with 3 feet of connector JX4, one end of resistance R11, one end of TVS pipe S1, TVS3 connect, one end of TVS pipe JX2, TVS pipe is connected after the other end of TVS2, TVS pipe JX2, TVS pipe is connected, the other end of TVS pipe JX4 homogeneous phase of connector JX2 is connected.

The beneficial effects of the utility model are that, after the direct contactor KM1 that detects is detected inserts detecting system, through the switching combination of switch QS1, QS2, QS3, can realize treating the direct contactor KM1 that detects and directly carry out conventional capability test and electrical life test, detection efficiency is high, can shorten check-out time, avoids frequently dismantling, and extravagant man-hour has reduced loaded down with trivial details operation process, reduces the cost of labor.

Drawings

FIG. 1 is an electrical wiring diagram of the present invention;

fig. 2 is a schematic circuit diagram of the main control module of the present invention.

Detailed Description

As shown in fig. 1 and fig. 2, the present invention relates to a detection system for a direct current charging contactor, which includes a direct current charging contactor KM1 to be detected, switches QS1, QS2, QS3, a contactor KM2, relays K1, KA2, a switching power supply SP1, a display LCD, an indicator light LE1, and a main control module, wherein a three-phase power supply (L, N terminal) is connected with the switching power supply SP1 after being connected with the relay K1, and ends a and B of the display LCD are respectively connected to 3 pins and 2 pins of a connector JX 4; two ends of the indicator light LE1 are respectively connected with a pin 3 and a pin 5 of the connector JX 2; the power supply comprises a switch power supply SP1, a switch power supply SP1, a connector JX2 pin and a normally open contact KA2-1 end of a relay KA2, a 24V output end of the switch power supply SP1 is connected with one ends of switches QS1, QS2 and QS3, the other end of the switch QS3 is connected with the display LCD and a connector JX1 pin, the other end of the normally open contact KA2-1 of the relay KA2 is connected with one ends of normally closed contacts KA1-2 of the relay KA1, one end of a direct contactor KM1 coil and one end of a contactor KM2 coil, the other end of the normally closed contact KA1-2 of the relay KA1 is connected with an indicator light LE1 and a connector JX2 pin 5, the other end of the relay KA1, one end of the relay KA2 coil, one end of the normally closed contact KA1-1, the other end of the direct contactor KM1 coil are connected, the other end of the normally closed contact KA1-1 normally closed contact is connected with a connector JX2 pin 4 pin, the other end of the connector JX2 coil is connected with a connector JX2, the other end of the relay KA coil is connected with a connector JX2 pin, and the other end of a connector is connected with a connector KM 3 pin of a direct contactor KM 3, the other end of a direct contactor KM 3.

The direct current contactor type relay circuit further comprises direct current terminal rows ZD1, ZD2 and a direct current power supply 2, wherein the direct current power supply 2 adopts a programmable direct current power supply of a model 2231A-30-3, the direct current power supply 2 is connected to two ends of a main contact of a direct contactor KM1, the direct current terminal row ZD1 is connected to a connection point between one end of a normally closed contact KA1-1 of the relay KA1 and the other end of a switch QS1, and the direct current terminal row ZD2 is connected to a connection point between the other end of a normally open contact KA2-1 of the relay KA2 and one end of a normally closed contact KA1-2 of the relay KA 1.

Be connected with resistive load circuit between direct contactor KM1 and contactor KM 2's the main contact, resistive load circuit is including the load 3, charging source module 4, BMS power 5 that connect gradually, and load 3 is connected with contactor KM 2's main contact one end, and BMS power 5's output is connected with direct contactor KM 1's main contact one end, and direct contactor KM 1's the main contact other end is connected with contactor KM 2's the main contact other end.

The main control module comprises a control panel 1, and a control circuit, a power supply circuit, a fault test circuit, a feedback detection circuit and a screen communication circuit are arranged on the control panel 1; the control circuit comprises a controller U1, a resistor R1 and a light emitting diode LED1; the controller U1 adopts a model N11HXB singlechip chip; the power supply circuit comprises a switching power supply U2, a voltage stabilizer U3, a resistor R2, an inductor L1, a diode D1, a light emitting diode LED2, capacitors C1-C4 and a connector JX1; the fault testing circuit comprises relays KA3 and KA4, a connector JX2, diodes D2 and D3, triodes Q1 and Q2 and resistors R3-R6; the feedback detection circuit comprises resistors R7 and R8, an optocoupler U4, a light-emitting diode LED3 and a connector JX3; the screen communication circuit comprises resistors R9-R11, a connector JX4, TVS tubes TVS 1-TVS 3, a transceiver U5, an inductor L2, capacitors C5, C6 and C7; the transceiver U5 adopts a model TD301D485H transceiving chip; the connectors JX1 to JX4 are arranged on the control board 1.

The controller U1 is divided into controllers U1A and U1B,

pins

33 and 35 of the controller U1A are connected with a power supply of 3.3V,

pins

60, 73 and 89 of the controller U1B are grounded, and pin 85 of the controller U1B is connected with the resistor R1 and the light emitting diode LED1 in sequence and then grounded;

a pin 1 of a switching power supply U2 is connected with a power supply 24V, a pin 3 of the switching power supply U2 is grounded, a pin 2 of the switching power supply U2 is connected with a cathode of a diode D1 and one end of an inductor L1, a pin 4 of the switching power supply U2 is connected with the other end of the inductor L1, one end of a capacitor C1, one end of a C2 and a pin 3 of a voltage stabilizer U3 and then connected with a power supply 5V, a pin 2 of the voltage stabilizer U3 is connected with a pin 4 of the voltage stabilizer U3, one end of a capacitor C3, one end of a resistor R2 is connected with a power supply 3.3V, the other end of the resistor R2 is connected with a cathode of a light emitting diode LED2, and a pin 5 of the switching power supply U2 is connected with a pin 1 of the voltage stabilizer U3, an anode of the diode D1, a cathode of the light emitting diode LED2, a cathode of the capacitor C1, a C2, a C3 and the other end of the C4 and then grounded;

pins

1 and 2 of the connector JX1 are connected and then grounded, and

pins

3 and 4 of the connector JX1 are connected and then connected with a power supply 24V;

one end of a coil of the relay KA3 is connected with the cathode of the diode D2 and then connected with a power supply 5V, the other end of the coil of the relay KA3 is connected with the anode of the diode D2 and the collector of the triode Q1, one end of a main contact of the relay KA3 is connected with one end of a main contact of the relay KA4, the other end of the main contact of the relay KA3 is connected with the 4 pin of the connector JX2, the other end of the main contact of the relay KA4 is connected with the 3 pin of the connector JX2, one end of a coil of the relay KA4 is connected with the cathode of the diode D3 and then connected with the power supply 5V, the other end of the coil of the relay KA4 is connected with the anode of the diode D3 and the collector of the triode Q2, the base of the triode Q1 is connected with one end of a resistor R3, the other end of the resistor R3 and the 26 pin of the controller U1A are connected, the other end of the resistor R4 is connected with the emitter of the triode Q1 and then connected with the ground, the base of the triode Q2 is connected with one end of the resistor R5, the other end of the emitter of the resistor R6 and the emitter of the triode Q2 are connected with the ground;

the positive electrode of the light emitting diode LED3 is connected with the pin 6 of the connector JX3, the negative electrode of the light emitting diode LED3 is connected with the pin 1 of the optocoupler U4, the pin 2 of the optocoupler U4 is grounded after passing through a connecting resistor R8, the pin 3 of the optocoupler U4 is grounded, the pin 4 of the optocoupler U4 is connected with one end of a resistor R7 and the pin 48 of the controller U1B, and the other end of the resistor R7 is connected with a power supply of 3.3V; one end of each of the capacitors C5 and C6 is connected with one end of the inductor L2 and then connected with a power supply of 3.3V, the other end of the inductor L2 is connected with one end of the capacitor C7 and a pin 1 of the transceiver U5, the other ends of the capacitors C5, C6 and C7 are connected with a pin 2 of the transceiver U5 and then grounded, a pin 3 of the transceiver U5 is connected with a pin 74 of the controller U1B through a connecting resistor R9, a pin 4 of the transceiver U5 is connected with a pin 75 of the controller U1B through a connecting resistor R10, transceiver U5's 5 feet connection director U1B's 70 feet, ground connection after transceiver U5's 10 feet and connector JX 4's 1 foot link to each other, transceiver U5's 9 feet and connector JX 4's 3 feet, resistance R11's one end, TVS pipe TVS1, TVS 3's one end homogeneous phase is connected, transceiver U5's 8 feet and resistance R11's the other end, TVS pipe TVS 2's one end, TVS pipe TVS 3's the other end, connector JX 4's 2 feet homogeneous phase is connected, TVS pipe TVS1, ground connection after TVS 2's the other end links to each other.

The direct current contactor to be tested is selected and placed in different circuits for testing, and the purpose is achieved through different switch combinations, so that frequent disassembly is avoided; carry out conventional capability test to direct current contactor earlier, carry out the electric life test again, finally carry out the temperature rise and switch over the test with carrying, the utility model discloses a concrete theory of operation is:

(taking EVQ250D1DA DC contactor as an example)

1. The method comprises the following steps of switching on a switch QS1, switching off a switch QS2 and switching off a switch QS3, and testing the contact resistance of a main contact of a direct contactor KM1 to be detected;

the testing steps are as follows:

(1) And consulting the specification of the sample: the main contact resistance (initial) specification is 1m Ω max. (at 1A);

(2) An LCR tester (model IM 3533) is connected to a direct contactor KM1, the direct contactor KM1 is always in an attraction state, and then a numerical value is read;

(3) And if the read resistance value is less than 3m omega, the result is qualified.

2. The method comprises the following steps of switching off a switch QS1, a switch QS2 and a switch QS3, and testing the insulation resistance value of a direct contactor KM1 to be detected;

(1) And consulting the specification of the sample: specification of insulation resistance: an initial state: 100M Ω min. End of life: 50M omega Min (measuring voltage DC500V, the same position of test position and dielectric withstand voltage item);

(2) A safety comprehensive tester (model SE 7430) is connected to a direct contactor KM1, the direct contactor KM1 is in a disconnected state, and then the numerical value is read;

(3) And if the read resistance value is larger than or equal to 100M omega, the term is qualified.

3. And (3) opening a switch QS1, opening a switch QS2 and closing a switch QS3, and testing the mechanical life of the direct current contactor KM 1. (control panel 1 controls the coil of direct current contactor KM1 to continuously attract and break, can set a time as a cycle period at will, and continuously detects the state of the auxiliary contact of direct current contactor KM1 and records the attracting and breaking times, and simultaneously control panel 1 controls display LCD to display the attracting and breaking times, if the attracting and breaking of direct current contactor KM1 is abnormal, control panel 1 outputs 12V voltage, indicator LE1 is normally on, counting is stopped, display LCD displays numerical value and test result, and the test is finished at the moment), specifically:

(1) And consulting the specification of the sample: mechanical life of DC contactor KM1 is 2 x 10 ⁵ Second (ON and OFF switching frequency, ON: OFF =0.5 second: 0.5 second)

(2) Setting a main control module to make the testing times of the display LCD greater than or equal to 2 multiplied by 10 ⁵ Secondly;

(3) And if the detection system normally operates until the test is completed, the direct current contactor is qualified.

4. The temperature rise of the direct current contactor KM1 is tested after 250A direct current passes through the direct current contactor KM1 for a period of time; specifically, the method comprises the following steps:

(1) And consulting the specification of the sample: the use environment temperature of the direct current contactor KM1 is-40 ℃ to +85 ℃;

(2) Connecting a direct current power supply 2 (model 2231A-30-3) into the detection system, and adjusting the direct current power supply 2 to output 250A current; a temperature measuring point of a temperature measuring instrument (model AT 4516) is connected to a main contact of a direct current contactor KM 1; starting a detection system to enable the direct current contactor KM1 to be in an attraction state all the time, and recording temperature measuring point data of a temperature measuring instrument after continuously applying 250A current for 1 hour;

(3) And if the temperature measurement data of the thermodetector is lower than +80 ℃, the test is qualified.

5. Switching on a switch QS2, switching off a switch QS3, and attracting or switching off the switch QS1, and carrying out an on-load switching test on the direct current contactor KM 1;

(1) And consulting the specification of the sample: the direct current contactor KM1 can bear 1000 times under the condition that the voltage is 600V and the current is 200A and the load is switched in the forward direction (the + A1 end of the direct current contactor KM1 flows into the-A2 end),

(2) Setting a main control module to enable the testing times of the display LCD to be more than or equal to 1000 times;

(3) The direct current contactor KM1 is connected into the detection system and then connected into the resistive load circuit; setting required voltage and current through a BMS power supply 5, enabling a charging power supply module 4 to output stable output voltage of about 600V and current of about 200A, and ensuring that the voltage and current loaded to the end of a direct current contactor KM1 are stabilized at about 600V 200A;

(4) The detection system normally operates until the test times are finished, and the direct current contactor is qualified; the test result shows the magnetic blow-out and arc extinguishing capability of the product during on-load switching, and plays a great role in the safety of the product in practical application.

To sum up, the utility model discloses can reach different test purposes through the switch combination of difference, avoid frequently dismantling, extravagant man-hour, only install once direct current contactor just can accomplish whole 5 tests, can audio-visually reflect out direct current contactor's state through display LCD's effect, can carry out fine verification to the electric life-span and the reliability of direct current contactor product.

It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.

Furthermore, it should be understood that although the present description refers to embodiments, not every embodiment may contain only a single embodiment, and such description is for clarity only, and those skilled in the art should integrate the description, and the embodiments may be combined as appropriate to form other embodiments understood by those skilled in the art.

Claims

1. The utility model provides a fill direct current contactor detecting system, its includes the direct current contactor KM1 that waits to detect, its characterized in that: it still includes switch QS1, QS2, QS3, contactor KM2, relay K1, KA2, switching power supply SP1, display LCD, pilot lamp LE1, main control module, three phase current source is through connecting behind the relay K1 with switching power supply SP1 is connected, display LCD, pilot lamp LE1 all connect in main control module, switching power supply SP 1's-24V output with display LCD, main control module, relay KA 2's normally open contact KA 2-1's one end homogeneous phase is connected, switching power supply SP 1's 24V output with switch QS1, QS2, QS 3's one end homogeneous phase is connected, switch QS 3's the other end with display LCD, main control module homogeneous phase are connected, relay KA 2's the other end with the one end of normally closed contact KA1-2, the one end of direct contactor KM1 coil connect, the one end of normally closed contact QS 1-2's normal open contact KA 1-2's one end, direct contactor KM2 coil connect, the other end of relay KA1-2 normal closed contact KA 1-2's normal open contact KA 1-2's one end direct contactor, relay KA 1-to the other end direct contactor KM1 coil connect the other end of relay KA 1-phase is connected with the other end of relay KA 1-phase current contactor.

2. The charging contactor detection system of claim 1, wherein: it still includes direct current terminal row ZD1, ZD2, DC power supply adopts model 2231A-30-3's programmable DC power supply, DC power supply connect in direct contactor KM1 main contact both ends, direct current terminal row ZD1 connect in on the tie point between the one end of relay KA 1's normally closed contact KA1-1 and the other end of switch QS1, direct current terminal row ZD2 connect in the other end of relay KA 2's normally open contact KA2-1 with on the tie point between the one end of relay KA 1's normally closed contact KA 1-2.

3. The charging direct current contactor detection system of claim 1, wherein: direct contactor KM1 with be connected with resistive load circuit between contactor KM 2's the main contact, resistive load circuit is including load, charging source module, the BMS power that connects gradually, the load with contactor KM 2's main contact one end is connected, the output of BMS power with direct contactor KM 1's main contact one end is connected, direct contactor KM 1's the main contact other end with contactor KM 2's the main contact other end is connected.

4. The charging direct current contactor detection system of claim 1, wherein: the main control module comprises a control board, and a control circuit, a power supply circuit, a fault test circuit, a feedback detection circuit and a screen communication circuit are arranged on the control board; the control circuit comprises a controller U1, a resistor R1 and a light emitting diode LED1; the controller U1 adopts a model N11HXB singlechip chip; the power supply circuit comprises a switching power supply U2, a voltage stabilizer U3, a resistor R2, an inductor L1, a diode D1, a light emitting diode LED2, capacitors C1-C4 and a connector JX1; the fault testing circuit comprises relays KA3 and KA4, a connector JX2, diodes D2 and D3, triodes Q1 and Q2 and resistors R3-R6; the feedback detection circuit comprises resistors R7 and R8, an optocoupler U4, a light emitting diode LED3 and a connector JX3; the screen communication circuit comprises resistors R9-R11, a connector JX4, TVS tubes TVS 1-TVS 3, a transceiver U5, an inductor L2, capacitors C5, C6 and C7; the transceiver U5 adopts a model TD301D485H transceiving chip.

5. The charging contactor detection system of claim 4, wherein: the controller U1 is divided into controllers U1A and U1B, pins 33 and 35 of the controller U1A are connected with a power supply of 3.3V, pins 34 and 36 of the controller U1A are connected with each other and then grounded, pins 88 and 90 of the controller U1B are connected with each other and then grounded, pins 60, 73 and 89 of the controller U1B are grounded, and pin 85 of the controller U1B is sequentially connected with the resistor R1 and the light emitting diode LED1 and then grounded; a pin 1 of the switching power supply U2 is connected with a power supply 24V, a pin 3 of the switching power supply U2 is grounded, a pin 2 of the switching power supply U2 is connected with a negative electrode of the diode D1 and one end of the inductor L1, a pin 4 of the switching power supply U2 is connected with the other end of the inductor L1, one end of the capacitors C1 and C2 and a pin 3 of the voltage stabilizer U3 and then connected with a power supply 5V, a pin 2 of the voltage stabilizer U3 is connected with a pin 4 of the voltage stabilizer U3, one ends of the capacitors C3 and C4 and the resistor R2 and then connected with a power supply 3.3V, the other end of the resistor R2 is connected with a negative electrode of the light-emitting diode LED2, and a pin 5 of the switching power supply U2 is connected with a pin 1 of the voltage stabilizer U3, an anode of the diode D1, a negative electrode of the light-emitting diode LED2, and the other ends of the capacitors C1, C2, C3 and C4 and then grounded; pins 1 and 2 of the connector JX1 are connected and then grounded, and pins 3 and 4 of the connector JX1 are connected and then connected with the power supply 24V; one end of the relay KA3 coil is connected with the negative electrode of the diode D2 and then connected with the power supply 5V, the other end of the relay KA3 coil is connected with the positive electrode of the diode D2 and the collector of the triode Q1, one end of the main contact of the relay KA3 is connected with one end of the main contact of the relay KA4, the other end of the main contact of the relay KA3 is connected with the 4 pin of the connector JX2, the other end of the main contact of the relay KA4 is connected with the 3 pin of the connector JX2, one end of the coil of the relay KA4 is connected with the negative electrode of the diode D3 and then connected with the power supply 5V, the other end of the coil of the relay KA4 is connected with the positive electrode of the diode D3 and the collector of the triode Q2, the base electrode of the triode Q1 is connected with one end of the resistor R3, the other end of the resistor R3 and the 26 pin of the controller U1A are connected, the other end of the resistor R4 is connected with the emitter of the triode Q1 and then grounded, the base electrode of the triode Q2 is connected with one end of the resistor R6 and the emitter of the controller U6; the positive electrode of the light emitting diode LED3 is connected to a pin 6 of the connector JX3, the negative electrode of the light emitting diode LED3 is connected to a pin 1 of the optocoupler U4, a pin 2 of the optocoupler U4 is connected with the resistor R8 and then grounded, a pin 3 of the optocoupler U4 is grounded, a pin 4 of the optocoupler U4 is connected with one end of the resistor R7 and a pin 48 of the controller U1B, and the other end of the resistor R7 is connected with a power supply of 3.3V; one end of each of the capacitors C5 and C6 is connected with one end of the inductor L2 and then connected with a power supply of 3.3V, the other end of the inductor L2 is connected with one end of the capacitor C7 and a pin 1 of the transceiver U5, the other ends of the capacitors C5, C6 and C7 are connected with a pin 2 of the transceiver U5 and then grounded, a pin 3 of the transceiver U5 is connected with a pin 74 of the controller U1B through the resistor R9, a pin 4 of the transceiver U5 is connected with a pin 75 of the controller U1B through the resistor R10, the 5 feet of the transceiver U5 are connected with the 70 feet of the controller U1B, the 10 feet of the transceiver U5 are connected with the 1 foot of the connector JX4 and then are grounded, the 9 feet of the transceiver U5 are connected with the 3 feet of the connector JX4, one end of the resistor R11, one ends of the TVS tubes TVS1 and TVS3, the 8 feet of the transceiver U5 are connected with the other end of the resistor R11, one end of the TVS tube TVS2, the other end of the TVS tube TVS3 and the 2 feet of the connector JX4, and the other ends of the TVS tubes TVS1 and TVS2 are connected and then are grounded.