CN112731002B

CN112731002B - Electromagnetic compatibility testing system and method for bidirectional vehicle-mounted charger

Info

Publication number: CN112731002B
Application number: CN202011343996.8A
Authority: CN
Inventors: 张仕彬; 邓俊泳; 黄鲲; 郭锦添; 胡凯
Original assignee: Vkan Certification And Testing Co ltd; China National Electric Apparatus Research Institute Co Ltd
Current assignee: Vkan Certification And Testing Co ltd; China National Electric Apparatus Research Institute Co Ltd
Priority date: 2020-11-25
Filing date: 2020-11-25
Publication date: 2023-07-11
Anticipated expiration: 2040-11-25
Also published as: CN112731002A

Abstract

The invention relates to an electromagnetic compatibility test system and method of a bidirectional vehicle-mounted charger, wherein the system comprises an alternating current input source, an alternating current electronic load, a control system, a low-voltage direct current power supply and a high-voltage direct current bidirectional power supply; the control system is respectively connected with the alternating current input source, the alternating current electronic load, the high-voltage direct current bidirectional power supply and the piece to be tested, controls the alternating current input source, the alternating current electronic load and the piece to be tested to be connected or not, sets the load characteristic of the alternating current electronic load, sets the input and output characteristics of the high-voltage direct current bidirectional power supply, controls the activation of the piece to be tested and sets the working mode of the piece to be tested. The invention can automatically test the electromagnetic compatibility of the bidirectional vehicle-mounted charger under different load conditions and different operation modes.

Description

Electromagnetic compatibility testing system and method for bidirectional vehicle-mounted charger

Technical Field

The invention belongs to the field of testing and verification of Bidirectional On-Board Charger (BOBC), and particularly relates to an electromagnetic compatibility testing system and method of a Bidirectional On-Board Charger.

Background

The vehicle-mounted charger is an important core part of the electric automobile, is installed in the electric automobile, and is an electric energy conversion device, and the vehicle-mounted charger can convert alternating current of a public power grid into direct current to charge a power battery pack of the electric automobile. The electric automobile with new energy sources at home and abroad is provided with a vehicle-mounted charger.

With the development and popularization of electric vehicles, the state promulgates a test standard of an alternating-current charger, namely a conduction type vehicle-mounted charger for electric vehicles, namely QC/T895-2011, and meanwhile, according to the latest ISO 16750-1 standard, namely ISO 16750-1:2018Road vehicles-Environmental conditions and testing for electrical and electronic equipment-Part 1: general "requirements, the operation mode of the tested sample is increased by" 3.3 maximum load operation "and" 3.4 minimum load operation ", and it can be seen that the industry increasingly pays attention to the performance of the tested sample under different load conditions.

The electromagnetic compatibility testing method of the traditional vehicle-mounted charger is that an alternating current input end of a testing piece is directly connected to a power grid, and a direct current output end of the testing piece is connected to a fixed-resistance resistor, as shown in fig. 1.

When in testing, the tested piece works in a fixed mode, the input of the alternating current power grid is connected to the tested piece through the power filter, the output of the tested piece is directly connected to a resistance load with a certain fixed resistance value, and then the electromagnetic compatibility performance test of the tested piece under the running condition is carried out, such as RE, CE, RI, CI and the like. If the operating conditions need to be changed, the software, load and the like of the tested piece need to be changed, and the process is restarted again. The manual operation is time-consuming.

Moreover, it is clear that the method can only test the charging mode of the vehicle-mounted charger and cannot test the electromagnetic compatibility in the discharging mode.

With the development of electric automobile technology, based on the application background of V2X (Vehicle to Everything), such as V2L (Vehicle to Load), vehicles supply power to the outside, and can be used for household outage or field camping, V2V (Vehicle To Vehicle), vehicle-to-Vehicle connection, electric automobile road rescue, V2G (Vehicle-to-grid), vehicle to a power grid, peak clipping and valley filling of the power grid, and the bidirectional application trend of a Vehicle-mounted charger is more and more obvious.

Because the bidirectional vehicle-mounted charger is a vehicle-mounted product newly developed in the years, an effective test and verification scheme is lacking. The electromagnetic compatibility test of the current bidirectional vehicle-mounted charger directly adopts the traditional test method. It is clear that the method has the following disadvantages for the bidirectional vehicle-mounted charger:

1. only the charging mode of the bidirectional vehicle-mounted charger can be tested, and the electromagnetic compatibility in the discharging mode can not be tested;

2. the output of the test piece is directly connected with the fixed resistance resistor, so that the electromagnetic compatibility under the fixed load condition can be tested, and different load conditions can not be tested;

3. the alternating current input of the test piece is directly connected to an alternating current power grid, so that no protective measures are taken, and the safety is not ensured;

4. automatic testing of multiple operation modes and multiple load conditions of the bidirectional vehicle-mounted charger cannot be achieved.

Disclosure of Invention

The invention aims to provide a system capable of automatically testing the electromagnetic compatibility of a bidirectional vehicle-mounted charger under different load conditions and different running modes (a charging mode and a discharging mode), and also provides an electromagnetic compatibility testing method based on the system, so that the dual purposes of fully verifying the product quality and improving the testing efficiency are achieved.

The technical scheme of the electromagnetic compatibility testing system is as follows: an electromagnetic compatibility testing system of a bidirectional vehicle-mounted charger comprises an alternating current input source, an alternating current electronic load, a control system, a low-voltage direct current power supply and a high-voltage direct current bidirectional power supply;

the control system is connected with an output line of the alternating current input source and an input line of the alternating current electronic load, controls whether the alternating current input source, the alternating current electronic load and the bidirectional vehicle-mounted charger to be tested are connected or not, and is further connected with the alternating current electronic load, the high-voltage direct current bidirectional power supply and the bidirectional vehicle-mounted charger to be tested respectively, sets the load characteristics of the alternating current electronic load, the input and output characteristics of the high-voltage direct current bidirectional power supply, controls the activation of the bidirectional vehicle-mounted charger to be tested and sets the working mode of the bidirectional vehicle-mounted charger to be tested.

The low-voltage direct current power supply adopts a storage battery.

The electromagnetic compatibility testing system also comprises a water cooler which is connected with the water inlet and the water outlet of the bidirectional vehicle-mounted charger to be tested through pipelines.

The electromagnetic compatibility testing system further comprises a junction box, the alternating current input source and the alternating current electronic load are connected with the bidirectional vehicle-mounted charger to be tested after passing through the junction box, the control system is connected with the junction box, and the control on whether the alternating current input source, the alternating current electronic load and the bidirectional vehicle-mounted charger to be tested are connected or not is realized by controlling the junction box;

the junction box comprises a shell and relays T1 and T2 arranged in the shell, wherein the relay T1 comprises four groups of normally open contacts, W and W ', V and V', U/L and U/L ', N and N', G1 are control signal input ends of the relay T1, the relay T2 comprises two groups of normally open contacts with common ends with the relay T1, namely U/L 'and L, N' and N_1, U/L 'and N' are common ends of the two groups of relays, and G2 is control signal input end of the relay T2;

the terminal W, V, U/L, N is used for connecting the alternating current input source, the terminals W ', V', U/L ', N' are used for connecting the bidirectional vehicle-mounted charger to be tested, and the terminal L, N _1 is used for connecting an alternating current electronic load.

The symbols W, W ', V, V', U/L, U/L ', N, N', L, N _1 described above are only used to distinguish between the different end points of the relay, e.g., W and W 'represent the two end points of one set of normally open contacts controlled in relay T1, V and V' represent the two end points of the other set of normally open contacts controlled in relay T1, and other compliance functions are similar.

The alternating current input source is unidirectional or three-phase AC. The junction box of the present invention is compatible with both sources of input.

As an optimal scheme, a power filter is arranged among the alternating current input source, the alternating current electronic load and the junction box, and the power filter is also arranged between the high-voltage direct current bidirectional power supply and the bidirectional vehicle-mounted charger to be tested.

And the control system, the junction box and a connecting circuit of the bidirectional vehicle-mounted charger to be tested are arranged in the waveguide tube.

The connecting pipeline of the water chiller and the bidirectional vehicle-mounted charger to be tested is also arranged in the waveguide tube.

During testing, the junction box and the bidirectional vehicle-mounted charger to be tested are arranged in the darkroom, the alternating current input source, the alternating current electronic load and the high-voltage direct current bidirectional power supply are arranged outside the darkroom and are respectively connected into the darkroom after being filtered and isolated by the power filter, and pipelines of the control system and the cold water machine are also respectively connected into the darkroom after being subjected to electromagnetic shielding by the waveguide tube, so that the measures are used for preventing the external electromagnetic signals of the darkroom from entering to influence the background radiation of the darkroom.

The control system is arranged outside the darkroom and comprises a control box serving as a control circuit of the junction box. The invention moves the control circuit of the junction box to the outside of the darkroom to make the control box, and prevents the background noise of the darkroom from being influenced by electromagnetic radiation of the control circuit while realizing the alternating current input/output control of the tested piece.

The W, V, U/L, N ends of the relay are also respectively connected in series with a fuse, and the fuses are also arranged in the shell of the control box.

The technical scheme of the electromagnetic compatibility testing method is as follows: an electromagnetic compatibility testing method based on the system comprises the following steps:

1) A charging mode testing step;

2) And a discharge mode testing step.

The charging mode testing step includes:

1-1) constant current charging mode test;

1-2) constant voltage charge mode test.

The constant current charging mode test comprises the following steps:

step 1 a), waking up a tested bidirectional vehicle-mounted charger, sending a charging mode instruction, enabling the tested bidirectional vehicle-mounted charger to enter a constant current charging mode and setting a charging current value;

step 2 a), setting a high-voltage direct-current bidirectional power supply as a constant-current electronic load;

step 3 a), controlling an alternating current input source to be communicated with a tested bidirectional vehicle-mounted charger;

and 4 a), testing the electromagnetic compatibility of the tested bidirectional vehicle-mounted charger in a constant current charging mode.

The constant voltage charge mode test includes the steps of:

step 1 b), waking up the tested bidirectional vehicle-mounted charger, sending a charging mode instruction, enabling the tested bidirectional vehicle-mounted charger to enter a constant voltage charging mode and setting a charging voltage value;

step 2 b), setting a high-voltage direct-current bidirectional power supply as a constant-voltage resistance load and setting a load resistance value;

step 3 b) controlling an alternating current input source to be communicated with a tested bidirectional vehicle-mounted charger;

and 4 b) testing the electromagnetic compatibility of the tested bidirectional vehicle-mounted charger in a constant voltage charging mode.

The discharge mode test comprises the following steps:

step 1 c), waking up the tested bidirectional vehicle-mounted charger, sending a discharge mode instruction, enabling the tested bidirectional vehicle-mounted charger to enter a discharge mode and setting the discharge voltage to be AC220V;

step 2 c), setting a high-voltage direct-current bidirectional power supply as constant-voltage output and setting an output voltage value;

step 3 c) setting an alternating current electronic load as a constant voltage resistance load and setting a resistance value;

step 4 c), communicating the alternating current electronic load with a tested bidirectional vehicle-mounted charger;

and 5 c) testing the electromagnetic compatibility of the tested bidirectional vehicle-mounted charger in a discharging mode.

The beneficial effects are that:

1) The electromagnetic compatibility testing system can automatically test the electromagnetic compatibility of the bidirectional vehicle-mounted charger under different load conditions and different running modes (a charging mode and a discharging mode), does not need to power down a prototype in the middle, does not need to replace a prototype power supply and a load, can save testing time and improves testing efficiency;

2) According to the invention, automatic switching of AC input of a power grid and AC output of a tested piece is realized through the junction box, the junction box is safe and reliable, and is flexible to design three-phase AC input and single-phase AC input compatible with a bidirectional vehicle-mounted charger, so that the junction is convenient and reliable, and the application range is wide;

3) According to the invention, the test system controls the signal line and the water pipe to carry out electromagnetic shielding by using the waveguide tube, so that the background radiation of the darkroom is prevented from being influenced due to the entering of electromagnetic signals outside the darkroom; alternating current input, alternating current output, high-voltage direct current input and output, and filtering isolation by using a power filter; the control circuit of the junction box is moved to the outside of the darkroom to be made into a control box, so that the background noise of the darkroom is prevented from being influenced by electromagnetic radiation of the control circuit while the alternating current input/output control of a tested piece is realized; the invention basically does not affect the background noise in the darkroom, and can well meet the electromagnetic compatibility background radiation index requirement of the darkroom.

4) The electromagnetic compatibility testing method provided by the invention is used for carrying out electromagnetic compatibility tests of different load conditions and different running modes (a charging mode and a discharging mode) on the test piece, wherein the charging mode test also comprises a constant-current charging mode test and a constant-voltage charging mode test, the actual working conditions in the whole vehicle operation are set and attached in the testing process, and the product quality can be fully verified by using the testing method provided by the invention.

Drawings

Fig. 1 is a block diagram of an electromagnetic compatibility test of a conventional vehicle-mounted charger;

FIG. 2 is a schematic diagram of a connection structure of an electromagnetic compatibility testing system of a bidirectional vehicle-mounted charger according to a preferred embodiment of the present invention during testing;

FIG. 3 is an electrical diagram of the interior of the junction box;

FIG. 4 is a schematic circuit diagram of the circuitry within the control box;

FIG. 5 is a flow chart of a method of electromagnetic compatibility testing of a bi-directional vehicle-mounted charger;

FIG. 6 is a flow chart of a charge mode test;

fig. 7 is a flow chart of discharge mode test.

Detailed Description

Fig. 2 is a schematic diagram of a connection structure of the electromagnetic compatibility testing system of the bidirectional vehicle-mounted charger according to the embodiment during testing. The low-voltage side and the junction box of the bidirectional vehicle-mounted charger (a tested piece) in the upper diagram are powered by a 12V storage battery. The single-phase or three-phase alternating current power grid input outside the darkroom is filtered by a power filter, so that the influence of the electromagnetic radiation level of a power signal on the background noise of the darkroom is avoided, and then the darkroom is connected to the input end of the junction box. One group of high-voltage outputs (three-phase four-wire or single-phase two-wire) of the junction box are connected to the high-voltage input end of the bidirectional vehicle-mounted charger, and the other group of high-voltage outputs (single-phase two-wire) are filtered by the power filter and connected to an alternating current electronic load outside the darkroom. The direct-current high-voltage output/input end of the bidirectional vehicle-mounted charger is filtered by a power filter and is connected to a high-voltage direct-current bidirectional power supply outside the darkroom.

The water inlet and the water outlet of the water chiller are respectively connected to the water outlet and the water inlet of the bidirectional vehicle-mounted charger through pipelines, and the bidirectional vehicle-mounted charger is cooled when in operation. And the water pipe of the cold water machine is also sleeved with a waveguide tube, so that electromagnetic signals outside the darkroom are prevented from being brought into the darkroom.

The CAN communication control line of the bidirectional vehicle-mounted charger is connected to a CAN card outside the darkroom after being shielded by the waveguide tube, and is converted into a USB interface to be connected to a test computer. The control signal wires (G1, G2, wakeup) of the control box are respectively connected to the junction box and the measured piece after being shielded by the waveguide tube. The AC electronic load and the high-voltage DC bidirectional power supply are connected to the switch through the network port and then are connected to the test computer. According to the embodiment, the tested piece and the peripheral equipment are controlled through CAN and LAN, and the bidirectional vehicle-mounted charger is awakened through a Wakeup signal, so that electromagnetic compatibility tests under different sample operation modes and different load conditions are realized.

As shown in fig. 3, the internal electrical connection of the junction box is that ac high voltage inputs W, V, U/L, N are respectively connected to 4 contacts of a relay T1 through fuses, 2 contacts (U/L 'and N') of the relay T1 are connected to contacts of a relay T2, G1 and G2 are relay coil control terminals, and the relay T1 and T2 control logic is as follows:

table 1 relay T1, T2 control logic table

Sequence number

Mode

G1

G2

Wakeup

T1

T2

1

Dormancy method

Invalidation (floor)

Disconnecting

2

Charging method

Effective (12V)

Invalidation (floor)

Effective (12V)

Suction-in

Disconnecting

3

Discharge of electric power

Invalidation (floor)

Effective (12V)

Disconnecting

Suction-in

As can be seen from table 1, when Wakeup is invalid (ground), the tested piece is in sleep mode; when Wakeup is effective (12V), the tested piece is awakened to normally work, and when the tested piece is in a charging mode, three-phase or single-phase alternating current input is connected to a high-voltage alternating current input end of the tested piece through the control of G1 and G2; when the tested object is in a discharging mode, the high-voltage alternating current single-phase output of the tested object is connected to an alternating current electronic load outside the darkroom through the junction box.

The control box part is mainly a control circuit of a junction box, the internal circuit of the control box is shown in fig. 4, a storage battery 12V is input into a power supply circuit and a high-side driving circuit, the power supply circuit converts the 12V into 5V to respectively supply power to a singlechip (MCU) and a CAN bus circuit, PTB0, PTC0 and PTC1 pins of the singlechip are connected to the high-side driving circuit, the output level of G1, G2 and Wakeup is controlled, and a CAN Module (MSCAN) of the singlechip is connected to a CAN card outside a darkroom through the CAN bus circuit and is converted into USB to be connected with a test computer.

The core chip of the internal circuit of the control box is selected as follows:

singlechip chip: MC9S08DZ128

High-side driving chip: VNQ5E050K-E

CAN bus chip: TJA1051T

And (3) a power chip: TLE6389-3GV50.

The flow of the electromagnetic compatibility testing method of the bidirectional vehicle-mounted charger is shown in fig. 5, the electromagnetic compatibility performance test under the charging mode is performed first, and then the electromagnetic compatibility performance test under the discharging mode is performed, so that the electromagnetic compatibility performance of the bidirectional vehicle-mounted charger under different working modes (working conditions related to normal operation of the whole vehicle) can be effectively tested and verified.

1. Charging mode test:

as shown in FIG. 6, wakeup outputs high level at the beginning of test, wake up the tested piece, the computer sends a charging mode instruction to the tested piece through the CAN bus, the tested piece enters constant current charging and sets a charging current value, and the high-voltage direct current bidirectional power supply is set as a constant current electronic load through the LAN bus. And then the computer outputs the G1 of the control box to high level through CAN bus control, the G2 is output to the ground, and the junction box realizes that the alternating current input is connected to a tested piece, so that the electromagnetic compatibility performance test of the tested sample under constant current charging CAN be performed.

After the test is finished, the tested piece enters constant voltage charging through the CAN bus and sets a charging voltage value, and then the high-voltage direct-current bidirectional power supply is set as a constant voltage resistance load and a load resistance value through the LAN bus, so that the electromagnetic compatibility performance test of the tested sample under the constant voltage charging CAN be performed.

2. Discharge mode test:

as shown in fig. 7, the computer outputs G1 and G2 of the control box to ground through CAN bus control, and the junction box realizes disconnection of ac input. The CAN bus sends a discharge mode instruction, the tested piece enters a discharge mode and sets the discharge voltage to be AC220V, the high-voltage direct-current bidirectional power supply is set to be constant-voltage output and set to be output voltage value through the LAN bus, and the alternating-current electronic load is set to be constant-voltage resistance load and set to be resistance value. And then G1 is output as ground, G2 is output as high level, and the junction box realizes that an alternating current resistor is loaded on the tested piece, so that the electromagnetic compatibility performance test of the tested piece in a discharging mode can be performed.

The charge mode and discharge mode test of the bidirectional vehicle-mounted charger are attached to the actual working conditions in the whole vehicle operation, and the bidirectional vehicle-mounted charger has good representative significance.

The invention can realize the automatic switching of different load conditions and different working modes and fully automatically complete the electromagnetic compatibility performance test.

The invention realizes the automatic switching of the AC input of the power grid and the AC output of the tested piece through the junction box, and is safe and reliable. And the three-phase alternating current input and the single-phase alternating current output of the bidirectional vehicle-mounted charger are flexibly designed and compatible, so that the wiring is convenient and reliable, and the application range is wider.

In addition, the test system of the invention adopts the following measures:

(1) The control signals of the CAN bus and the control box are electromagnetically shielded by the waveguide tube, so that the background radiation of the darkroom is prevented from being influenced due to the entering of external electromagnetic signals of the darkroom;

(2) Alternating current input, alternating current output, high-voltage direct current input and output, and filtering isolation by using a power filter;

(3) The control circuit of the junction box is moved to the outside of the darkroom to be made into a control box, so that the background noise of the darkroom is prevented from being influenced by electromagnetic radiation of the control circuit while the alternating current input/output control of a tested piece is realized;

basically, the method has no influence on the background noise in the darkroom, and meets the electromagnetic compatibility background radiation index requirement of the darkroom.

Claims

1. An electromagnetic compatibility test method of an electromagnetic compatibility test system based on a bidirectional vehicle-mounted charger, wherein the electromagnetic compatibility test system comprises an alternating current input source, an alternating current electronic load, a control system, a low-voltage direct current power supply and a high-voltage direct current bidirectional power supply;

the control system is connected with an output line of the alternating current input source and an input line of the alternating current electronic load, controls whether the alternating current input source, the alternating current electronic load and the bidirectional vehicle-mounted charger to be tested are connected or not, is also connected with the alternating current electronic load, the high voltage direct current bidirectional power supply and the bidirectional vehicle-mounted charger to be tested respectively, sets the load characteristic of the alternating current electronic load, sets the input and output characteristics of the high voltage direct current bidirectional power supply, controls the activation of the bidirectional vehicle-mounted charger to be tested and sets the working mode of the bidirectional vehicle-mounted charger to be tested;

the electromagnetic compatibility testing method is characterized by comprising the following steps of:

1) A charging mode testing step;

2) A discharge mode testing step; the discharge mode test comprises the following steps:

2. The electromagnetic compatibility testing method of claim 1, wherein the charging mode testing step includes:

1-1) constant current charging mode test;

1-2) constant voltage charge mode test.

3. The electromagnetic compatibility testing method of claim 2, wherein the constant current charging mode test includes the steps of:

4. The electromagnetic compatibility test method of claim 3, wherein the constant voltage charge mode test includes the steps of:

5. The method according to claim 1, wherein the electromagnetic compatibility testing system further comprises a water chiller connected to the water inlet and the water outlet of the bidirectional vehicle-mounted charger to be tested through pipelines.

6. The electromagnetic compatibility testing method according to claim 5, wherein the electromagnetic compatibility testing system further comprises a junction box, the alternating current input source and the alternating current electronic load are connected with the bidirectional vehicle-mounted charger to be tested after passing through the junction box, the control system is connected with the junction box, and the control of whether the alternating current input source and the alternating current electronic load are connected with the bidirectional vehicle-mounted charger to be tested or not is achieved by controlling the junction box;

7. The electromagnetic compatibility testing method of claim 6, wherein a power filter is arranged among the alternating current input source, the alternating current electronic load and the junction box, and a power filter is also arranged between the high-voltage direct current bidirectional power supply and the bidirectional vehicle-mounted charger to be tested;

the control system, the junction box and the connecting circuit of the bidirectional vehicle-mounted charger to be tested are arranged in the waveguide tube;

8. The electromagnetic compatibility testing method of claim 7, wherein the control system is disposed outside of a darkroom and includes a control box as a control circuit for the junction box.