CN111521943B

CN111521943B - Battery cycle tester and testing method thereof

Info

Publication number: CN111521943B
Application number: CN202010571148.6A
Authority: CN
Inventors: 吴浩; 王智; 张冬娟
Original assignee: XIANGTAN YINHE NEW ENERGY CO Ltd
Current assignee: Yinhe Chengtai (Shandong) Technology Co.,Ltd.
Priority date: 2020-06-22
Filing date: 2020-06-22
Publication date: 2021-02-19
Anticipated expiration: 2040-06-22
Also published as: CN111521943A

Abstract

The invention discloses a battery cycle tester, which comprises a master-battery PACK, a slave-battery PACK, a charge-discharge loop and a bidirectional power module, wherein the slave-battery PACK is a tested battery PACK, the charge-discharge loop comprises relays J1, J2, J3, J4, relays K1, K2, K3 and K4, the positive electrode of the slave-battery PACK is connected with a first public end of J3 and a first public end of J2 through a high-voltage switch, the positive electrode of the master-battery PACK is connected with a first normally-open contact of J4 and a first normally-open contact of J1, the first normally-open contact of J3 and the first public end of J4 are connected with the positive electrode of the input end of the bidirectional power module, and the first normally-open contact of J2 and the first public end of J1 are connected with the positive electrode of the output end of the bidirectional power module; the invention also discloses a testing method of the battery cycle tester, which realizes the recycling of the discharge capacity of the PACK group of the tested battery.

Description

Battery cycle tester and testing method thereof

Technical Field

The invention relates to the technical field of batteries, in particular to a battery cycle tester and a testing method thereof.

Background

With the vigorous development of the new energy automobile industry and the wide application of the lithium ion battery, the role played by the PACK group of the lithium ion battery is more and more important. In order to ensure the consistency of the monomer capacities among the battery PACK groups, the battery PACK group cycle test refers to charging and discharging the battery unit and the lithium battery PACK for multiple times so as to execute a life and reliability test. To ensure that each cell and battery PACK will function properly, each lithium battery PACK must be functionally tested after manufacture before delivery to the end customer. Energy needs to be acquired during battery charging test, and the energy is generally connected to a load or fed back to a power grid during battery discharging test, so that the energy consumption is large, and the test cost is increased; when the battery PACK groups with different strings are measured, the required voltage and current requirements are different, the frequent replacement of the testing device is inconvenient to execute and increases the cost, and if the safety protection of the battery is not performed in the battery test, unnecessary loss is brought to the test. Therefore, a battery PACK cycle test device which can recycle the discharge capacity, has high safety, is suitable for different voltages and large currents, and can recycle the discharge capacity is needed.

Disclosure of Invention

Technical problem to be solved

Based on the problems, the invention provides a battery cycle tester and a testing method thereof, wherein a master-battery PACK charges a tested slave-battery PACK through a bidirectional power module to perform a charging test, and a slave-battery PACK charges the tested master-battery PACK through the bidirectional power module to perform a discharging test, so that the recycling of the discharging capacity of the tested battery PACK is realized.

(II) technical scheme

Based on the technical problem, the invention provides a battery cycle tester, which comprises a master _ battery PACK, a slave _ battery PACK, a charging and discharging loop and a bidirectional power module, wherein the slave _ battery PACK is a battery PACK to be tested, the charging and discharging loop comprises relays J1, J2, J3, J4, relays K1, K2, K3 and K4, the positive electrode of the slave _ battery PACK is connected with a first common end of J3 and a first common end of J2 through a high-voltage switch, the positive electrode of the master _ battery PACK is connected with a first normally open contact of J4 and a first normally open contact of J1, the first normally open contact of J3 and the common end of J4 are connected with the positive electrode of the input end of the bidirectional power module, and the first normally open contact of J2 and the common end of J1 are connected with the positive electrode of the output end of the bidirectional power module; a second common end of the J3 is connected with a first normally closed contact of the K4, a second common end of the J3 is connected with a negative coil of the K3, a positive coil of the J3 is connected with a first normally closed contact of the K4, and a negative coil of the J3 and a second normally open contact of the J89are; a second common end of the J2 is connected with a first normally closed contact of the K2, a second common end of the J2 is connected with a negative coil of the K1, a positive coil of the J2 is connected with a first normally closed contact of the K2, and a negative coil of the J2 and a second normally open contact of the J89are; a second common end of the J4 is connected with a first common end of the K4, a positive electrode of the coil is connected with a first common end of the K3, and a negative electrode of the coil is grounded with a second normally-open contact; a second common end of the J1 is connected with a first common end of the K2, a positive electrode of the coil is connected with a first common end of the K1, and a negative electrode of the coil is grounded with a second normally-open contact; the positive poles of the coils of K1, K2, K3 and K4 are all connected with ACC, the normally closed contact of K1 is connected with the CTRL end of BSMU, the common end of K2 is connected with the CH end of BSMU, the normally closed contact of K3 is connected with the HVDC end of BSMU, and the common end of K4 is connected with the AP end of BSMU; the negative pole of the input end of the bidirectional power module, the negative pole of the output end of the bidirectional power module, the negative pole of the master-battery PACK and the negative pole of the slave-battery PACK are all connected, and the BSMU is a battery management unit and is in communication connection with the battery cycle test screen through an RS232 interface.

Furthermore, the battery circulation tester also comprises a slave _ BECU, a master _ BECU, a PLC control board and a relay K5, wherein a public end one and a public end two of the relay K5 are in communication connection with the PLC control board through a CAN, a negative electrode of a coil is grounded, a positive electrode of the coil is connected with an AIR end of the BSMU, a normally closed contact one and a normally closed contact two are in communication connection with the master _ BECU through the CAN, and a normally open contact one and a normally open contact two are in communication connection with the slave _ BECU through the CAN; the master _ BECU is in communication connection with the master _ battery PACK and the BMSU through a CAN, and the slave _ BECU is in communication connection with the slave _ battery PACK and the BMSU through the CAN; the PLC control board is in communication connection with the output end of the bidirectional power module through a CAN;

the end OC2 of the BSMU is connected with the end CC2 of the master _ BECU, the end OE2 is grounded and used for transmitting a master _ battery PACK charging connection confirmation signal, the end OC1 is connected with the end CC2 of the slave _ BECU, the end OE1 is grounded and used for transmitting a slave _ battery PACK charging connection confirmation signal, the end OUT3 is connected with the end CC1 of the PLC control board and used for transmitting a charger connection confirmation signal, the end OE3 is grounded after being connected with the coil K6B of the relay K6 and used for transmitting a starting signal, and the end M/IO of the PLC control board is connected with the end K6A of the normally open contact of the relay K6 and grounded after being started by a signal switch.

Further, the battery cycle tester also comprises an auxiliary power module, wherein IN3, IN4 and IN5 at the input end of the auxiliary power module are connected with the three-phase alternating current of a power grid, IN1 at the input end protects grounding PE, the positive pole of the output end is connected with the positive pole of the output end of the bidirectional power module, the negative pole of the output end is connected with the negative pole of the output end of the bidirectional power module, and the output end is connected with the BSMU through CAN communication.

Furthermore, the ends IN1, IN2, IN3 and IN4 of the BSMU are respectively connected with the common end two of the relays J1, J2, J3 and J4, and are used for pull-IN feedback detection of the corresponding relays.

Furthermore, the anode and the cathode of the output end of the bidirectional power module are respectively connected with the HV + and the HV-ends of the PLC control panel; the positive pole OUT1 and the negative pole OUT4 of the output end of the auxiliary power module are respectively connected with the HV + and the HV-ends of the BSMU; the HV + and HV-ends of the main _ BECU are respectively connected with the positive electrode and the negative electrode of the main _ battery PACK; HV + and HV-terminals of the slave _ BECU are respectively connected with the positive electrode and the negative electrode of the slave _ battery PACK; for voltage sampling.

Further, the current sampling end of the master _ BECU is connected to a master _ current sampling module E1 located at the positive electrode of the master _ battery PACK, the current sampling end of the slave _ BECU is connected to a slave _ current sampling module E2 located at the positive electrode of the slave _ battery PACK, the current sampling end of the BSMU is connected to a slave _ current sampling module E3 located at the positive electrode of the output end of the auxiliary power module, the current sampling end of the PLC control board is connected to a power module _ current sampling module E4 located between the positive electrode of the output end of the bidirectional power module and the charge-discharge loop, the master _ current sampling module, the slave _ current sampling module and the auxiliary _ current sampling module are all LEM-900S, and the power module _ current sampling module is CS400 ET.

Further, the bidirectional power module comprises an AC/DC module REG75035 with parallel bidirectional conversion, and the auxiliary power module comprises 1 AC/DC module REG75035 with bidirectional conversion.

The invention also discloses a testing method of the battery cycle tester, which comprises the steps that the master _ battery PACK charges the slave _ battery PACK and the slave _ battery PACK charges the master _ battery PACK;

when the master _ battery PACK charges the slave _ battery PACK: selecting a master-battery PACK to charge a slave-battery PACK on a battery cycle test display screen, controlling J4 attracting by BMSU through K3, controlling J4 the positive pole of the master-battery PACK to the positive pole of the input end of a bidirectional power module through J4, connecting the negative pole of the input end of the bidirectional power module with the negative pole of the master-battery PACK, controlling J2 attracting by BMSU through K2, returning the positive pole of the output end of the bidirectional power module to the positive pole of the slave-battery PACK through J2, and connecting the negative pole of the output end of the bidirectional power module with the negative pole of the slave-battery PACK to realize that the master-battery PACK charges the slave-battery PACK;

the slave _ battery PACK charges the master _ battery PACK: the method comprises the steps that a main-battery PACK is charged by selecting a slave-battery PACK on a battery cycle test display screen, a BMSU controls J3 to attract through K4, the positive pole of the slave-battery PACK is connected to the positive pole of the input end of a bidirectional power module through J3, the negative pole of the input end of the bidirectional power module is connected with the negative pole of the slave-battery PACK, the BMSU controls J1 to attract through K1, the positive pole of the output end of the bidirectional power module returns to the positive pole of the main-battery PACK through J1, the negative pole of the output end of the bidirectional power module is connected with the negative pole of the main-battery PACK, and the slave-battery PACK charges the main-battery PACK.

Further, the testing method further comprises a hardware high-voltage interlock, wherein the hardware high-voltage interlock comprises:

hardware high-voltage interlock of J3 with J4: when J4/J3 is attracted, the first common end of J4/J3 is grounded in a closed mode, the negative electrode of the coil of the connected K4/K3 is grounded, the relay K4/K3 is attracted, and the relay J3/J4 is controlled to be disconnected by K4/K3;

hardware high-voltage interlock of J1 with J2: when J2/J1 is attracted, the first common end of J2/J1 is closed and grounded, the negative electrode of the coil of the connected K1/K2 is grounded, the relay K1/K2 is attracted, and the relay J1/J2 is controlled to be disconnected by K1/K2.

Further, the test method also comprises the steps of protecting the battery PACK monomer from overcharge and overdischarge:

over-discharge protection of battery PACK monomer: when the battery PACK is discharged, if the voltage of a certain battery cell reaches the set lower limit voltage, the corresponding J3/J4 is disconnected, and the auxiliary power module outputs the requested voltage/current from the power grid to continuously charge the charged battery PACK through the corresponding J1/J2;

overcharge protection of battery PACK monomer: when the battery PACK is charged, if the voltage of one battery cell reaches the set upper limit voltage, the corresponding J1/J2 is disconnected, so that the charged battery PACK stops charging.

(III) advantageous effects

The technical scheme of the invention has the following advantages:

(1) the battery circulation tester can recycle the discharge energy through the main-battery PACK, saves energy, can adjust the voltage/current of the bidirectional power module or the auxiliary power module through the upper computer, meets the battery PACK test with different voltage and different current requirements, does not need to replace test equipment, and greatly reduces the test cost;

(2) the invention has the hardware high-voltage interlocking and overcharge-overdischarge protection functions, has a safer protection mechanism, prolongs the service life of the battery cycle tester and reduces the accidental damage of the test to the BACK of the tested battery;

(3) the charging and discharging hardware is integrated, bidirectional charging and discharging are realized, equipment is used to the maximum extent, the volume is saved, the output value of unit area is improved, and the charging and discharging device has multiple charging modes and higher control precision;

(4) the invention is in modular design, each module has independent operation capability, so that each module can be flexibly and randomly combined, the tested battery PACK can be conveniently replaced, the operation and maintenance are convenient, and the system stability is improved;

(5) the conversion efficiency of the invention is far higher than 90%, the conversion efficiency is improved, and the cost is saved.

Drawings

The features and advantages of the present invention will be more clearly understood by reference to the accompanying drawings, which are illustrative and not to be construed as limiting the invention in any way, and in which:

FIG. 1 is a schematic diagram of a battery cycler circuit according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of a charge and discharge circuit according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of a bi-directional power module and an auxiliary power module according to an embodiment of the invention;

FIG. 4 is a wiring diagram of a PLC control board according to an embodiment of the present invention;

FIG. 5 is a wiring diagram of the Slave _ BECU according to an embodiment of the present invention;

FIG. 6 is a wiring diagram of the Master _ BECU according to an embodiment of the present invention;

FIG. 7 is a wiring diagram of a BSMU in accordance with an embodiment of the present invention;

fig. 8 is a schematic diagram of a master _ cell PACK and a slave _ cell PACK according to an embodiment of the present invention.

Detailed Description

The following detailed description of embodiments of the present invention is provided in connection with the accompanying drawings and examples. The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention.

A battery cycling tester, as shown in FIG. 1, includes a master _ battery PACK, a slave _ battery PACK, a charge and discharge circuit, a bidirectional power module U1, an auxiliary power module U2, a master _ BECU1, a slave _ BECU2, BSMU, a PLC control board, a relay K5 for switching the charging direction, a master _ battery PACK screen, a slave _ battery PACK screen, and a battery cycling test screen, the slave _ battery PACK being a battery PACK under test, the master _ battery PACK being 8 battery PACK groups PACK11-PCK18 connected in series, the slave _ battery PACK being 8 battery PACK groups 21-PCK28 connected in series, the bidirectional power module including a plurality of bidirectional switching AC/DC modules 75035 connected in parallel, the auxiliary power module being 1 bidirectional switching AC/DC modules 75035, the master _ BECU and slave _ PACK unit respectively representing the control REG of the master _ PACK and slave battery PACK control unit, the BSMU represents a battery management main unit and is used for controlling the charging and discharging loop, the relay K5 is used for switching the connection between the PLC control panel and the master-battery PACK or the slave-battery PACK, so as to switch the charging and discharging modes of the master-battery PACK to charge the slave-battery PACK or the slave-battery PACK to charge the master-battery PACK, the master-battery PACK screen and the slave-battery PACK screen respectively display the data information of the master-battery PACK and the slave-battery PACK according to the detection results of the master-battery PACU and the slave-battery PACU, the charger screen is used for displaying the charging state of the charging battery, and the battery circulation test screen is used for displaying the test state of the master-battery PACK and the slave-battery PACK and is provided with a button to start the test and switch the charging direction. The master _ BECU, the slave _ BECU and the BSMU are the same 3 modules, which are HVWQV3.4.1. The PLC control panel is a charger control panel, and the charger comprises a master-battery PACK for charging a slave-battery PACK and a slave-battery PACK for charging the master-battery PACK.

The master _ battery PACK is connected with the slave _ battery PACK through the charge-discharge loop, the charge-discharge loop comprises vacuum relays J1, J2, J3 and J4(SCII EV350-24PDH) and relays K1, K2, K3 and K4 (ohm dragon relays) as shown in fig. 2, the positive electrode of the slave _ battery PACK is connected with a first common end (namely a pin 5) of J3 and a first common end (namely a pin 5) of J2 through a high-voltage switch, and the positive electrode of the master _ battery PACK is connected with a first normally open contact (namely a pin 3) of J4 and a first normally open contact (namely a pin 3) of J1; a second common end (namely a pin 6) of the J3 is connected with an IN3 end of the BSMU and a coil cathode (namely a pin 8) of the K3, a coil anode (namely a pin 7) is connected with a first normally closed contact (namely a pin 1) of the K4, and the coil cathode (namely the pin 8) and a second normally open contact (namely a pin 4) are grounded; a second common end (namely a pin 6) of the J2 is connected with an IN2 end of the BSMU and a coil cathode (namely a pin 8) of the K1, a coil anode (namely a pin 7) is connected with a first normally closed contact (namely a pin 1) of the K2, and the coil cathode (namely the pin 8) and a second normally open contact (namely a pin 4) are grounded; a second common terminal (namely a pin 6) of the J4 is connected with an IN4 terminal of the BSMU and a coil cathode (namely a pin 8) of the K4, a coil anode (namely a pin 7) is connected with a first common terminal (namely a pin 5) of the K3, and the coil cathode (namely the pin 8) is grounded with a second normally-open contact (namely a pin 4); a second common terminal (namely a pin 6) of the J1 is connected with an IN1 terminal of the BSMU and a coil cathode (namely a pin 8) of the K2, a coil anode (namely a pin 7) is connected with a first common terminal (namely a pin 5) of the K1, and the coil cathode (namely the pin 8) is grounded with a second normally-open contact (namely a pin 4); the positive poles (namely pins 7) of the coils of K1, K2, K3 and K4 are connected with ACC of 24V, a normally closed contact I (namely pin 1) of K1 is connected with the CTRL end of BSMU, a common end I (namely pin 5) of K2 is connected with the CH end of BSMU, a normally closed contact I (namely pin 1) of K3 is connected with the HVDC end of BSMU, and a common end I (namely pin 5) of K4 is connected with the AP end of BSMU; a common end I (namely a pin 3) of a normally open contact I (namely a pin 3) of J3 and a common end I (namely a pin 5) of J4 are connected with a positive electrode IN3 of an input end of the bidirectional power module, and a common end I (namely a pin 3) of a normally open contact I (namely a pin 3) of J2 and a common end I (namely a pin 5) of J1 are connected with a positive electrode OUT1 of an output end of the bidirectional power module and a positive electrode OUT1 of an output end of the auxiliary power module;

as shown IN fig. 3, IN1 at the input end of the bidirectional power module and IN1 at the input end of the auxiliary power module both protect the ground PE, IN3, IN4, and IN5 at the input end of the auxiliary power module are connected to the three-phase alternating current of the power grid, and the negative electrodes IN5 at the input end of the bidirectional power module, OUT4 at the output end of the bidirectional power module, OUT4 at the output end of the auxiliary power module, PACK (master _ battery PACK) being the negative electrode of PACK11, and PACK (slave _ battery PACK) being the negative electrode of PACK21 are connected, that is, high voltage is common negative; the OUT6 and the OUT7 at the output end of the bidirectional power module are connected with a PLC control panel CAN1 for communication through CAN communication, and transmit the input and output voltage/current, the running state information and the like of the bidirectional power module, the OUT6 and the OUT7 at the output end of the auxiliary power module are connected with BSMU _ CAN3 for communication through CAN communication, and transmit the input and output voltage/current, the running state information and the like of the auxiliary power module; the positive pole OUT1 and the negative pole OUT4 of the output end of the bidirectional power module are respectively connected with the HV + and the HV-ends of the PLC control panel and used for sampling charging voltage, the positive pole OUT1 and the negative pole OUT4 of the output end of the auxiliary power module are respectively connected with the HV + and the HV-ends of the BSMU and used for sampling voltage at the output end of the auxiliary power module, an auxiliary _ current sampling module E3, namely LEM-900S, is arranged at the positive pole OUT1 of the output end of the auxiliary power module and used for sampling current at the output end of the auxiliary power module, and a power _ current sampling module E4, namely CS400ET, is arranged between the positive pole of the output end of the bidirectional power module and a charging and discharging loop and used for sampling charging current.

The PLC control board and the relay K5 are shown in fig. 4, CAN1H and CAN1L of the PLC control board are connected with OUT6 and OUT7 of the output end of the bidirectional power module through CAN1 communication, and transmit input/output voltage/current, operation state information and the like of the bidirectional power module, CAN2H and CAN2L of the PLC control board are connected with a first common end (i.e. pin 5) and a second common end (i.e. pin 6) of the relay K5 through CAN2 communication, a negative coil (i.e. pin 8) of the relay K5 is grounded, a positive coil signal is connected with AIR of BSMU, a first normally closed contact (i.e. pin 1) and a second normally closed contact (i.e. pin 2) are connected with 2H and 2L of the master BECU through CAN communication, a first normally open contact (i.e. pin 3) and a second normally open contact (i.e. pin 4) are connected with 2H and 2L of the slave BECU through CAN communication, and K5 is switched, so that the PLC control board is connected with 2H and 2L, transmitting a handshake protocol established by the master/slave _ BECU module and the charger at the initial stage, and transmitting requested voltage/current, battery monomer information and the like to the PLC; the PLC control panel is in communication connection with a charger display screen through an RS232 interface and is used for transmitting charging state information; the HALL _ IN, DGAN and HALL _5V ends of the PLC control board are connected with E4 for current sampling and used for monitoring the charging and discharging capacity of the battery PCAK group, and the 0-750V/HV + and AGND/HV-ends of the PLC control board are respectively connected with the anode and the cathode of the output end of the bidirectional power module for voltage sampling; the M/IO end of the PLC is connected with a normally open contact switch K6A of a relay K6 and then grounded, a ground charger starting signal is pulled, the CC1 end of the PLC is connected with the OUT3 end of the BSMU through R4 ═ 500 Ω, and a charger connection confirmation signal is transmitted; the Temperature detection end Temperature and the DGND end of the PLC control board are connected with the thermistor NTC4 in parallel to detect the Temperature, the output end of the K _ OUT3 is connected with the charging display lamp and then grounded, and the input power end adopts 24V ACC for power supply.

As shown in fig. 5, the slave _ BECU, that is, BECU2, 1H and 1L of the slave _ BECU are in communication connection with CANH and CANL of PACK21 and 2H and 2L of BMSU through CAN1 to transmit the voltage, temperature and voltage/current on the dc bus of each cell of the slave _ battery PACK group and to transmit the slave _ battery PACK and the working state of the charger, the

slave _ BECU

2H and 2L are in communication connection with the PLC control board CAN2 through the normally closed contact one (that is, pin 1) and the normally closed contact two (that is, pin 2) of the relay K5, and the

slave _ BECU

3H and 3L are in communication connection with the slave _ battery PACK _ screen through CAN3 and then to RS232 for transmitting the state information of the slave _ battery PCAK; connecting the CC2 end of the _ BECU with the OC1 end of the BSMU through R2 ═ 1K Ω, transmitting a charging connection confirmation signal of the slave _ battery PACK, connecting the positive electrode and the negative electrode of the slave _ battery PACK, namely BAT + of PACK28 and BAT-of PACK21 respectively from the HV + and HV-ends of the _ BECU, and sampling the voltage of the slave _ battery PACK from CT, GND and E2 from the CT and GND of the _ BECU and the E2 of the +5V connection; the TEMP1 and TEMP2 of the slave _ BECU are connected in parallel with the thermistor NTC2 to detect temperature, and the input power supply end adopts 24V ACC power supply.

As shown in fig. 6, 1H and 1L of the main _ BECU are in communication connection with CANH and CANL of PACK11, and 1H and 1L of BMSU are in communication connection with CAN1, and are used for transmitting the voltage, temperature and voltage/current on a direct current bus of each cell of the main _ battery PACK group, and transmitting the main _ battery PACK and the working state of a charger, 2H and 2L of the main _ BECU are in communication connection with a PLC control board CAN2 through a normally closed contact one (i.e. a pin 3) and a normally closed contact two (i.e. a pin 4) of a relay K5, and 3H and 3L of the main _ BECU are in communication connection with a main _ battery PACK _ screen through CAN3 and then are communicated to RS232 for transmitting the state information of the main _ battery PCAK; the CC2 end of the main _ BECU is connected with the OC2 end of the BSMU through R1-1K omega to transmit a main _ battery PACK charging connection confirmation signal, the HV + and HV-ends of the main _ BECU are respectively connected with the positive pole and the negative pole of the main _ battery PACK, namely BAT + of PACK18 and BAT-of PACK11 are used for voltage sampling of the main _ battery PACK, and CT, GND and +5V of the main _ BECU are connected with E1 for current sampling of the main _ battery PACK; the temperature detection ends TEMP1 and TEMP2 of the main _ BECU are connected with the thermistor NTC3 in parallel to detect the temperature, and the input power end adopts an ACC (adaptive control center) of 24V for power supply.

As shown in fig. 7, 1H and 1L of the BSMU are communicatively connected with CANH and CANL of 1H and 1L, PACK11 of the master _ battery PACK through CAN1, 2H and 2L of the BSMU are communicatively connected with CANH and CANL of 1H and 1L, PACK21 of the slave _ battery PACK through CAN1, and 3H and 3L of the BSMU are communicatively connected with OUT6 and OUT7 of the output end of the auxiliary power module through CAN; an OC2 end signal of the BSMU is connected with a CC2 end of a master _ BECU through a R1-1K omega, an OE2 end is grounded, a CAN2 communication signal confirmed by main _ battery PACK charging connection is transmitted, an OC1 end signal of the BSMU is connected with a CC2 end of a slave _ BECU through a R2-1K omega, an OE1 end is grounded, and a CAN2 communication signal confirmed by slave _ battery PACK charging connection is transmitted; the OE3 end of the BSMU is connected with a coil K6B of a relay K6 and then grounded, a charging starting signal is obtained, after charging is started, the K6B is attracted, and the M/IO end of the PLC module is pulled to the ground by the K6A; the OUT3 end of the BSMU is connected with the CC1 end of the PLC control panel through a resistor R4 which is 500 omega, a charger connection confirmation signal is transmitted, the low level of the signal is effective, and the BSMU can enter the next link only after the charger connection confirmation signal and the master/slave _ battery PACK charging connection confirmation signal are detected and confirmed; the CC2 end of the BSMU is grounded through a resistor R3 which is 1K omega and an emergency stop button which is a normally closed switch, and is used as a battery cycle test confirmation signal, and the battery cycle test is emergently stopped by pressing; the AIR end of BSMU is connected with the coil anode (namely pin 7) of relay K5 to control the switch of relay K5; the CTRL, CH, HVDC and AP ends of the BSMU are respectively connected with a first normally closed contact (namely a pin 1) of the relay K1, a first common end (namely a pin 5) of the K2, a first normally closed contact (namely a pin 1) of the K3 and a first common end (namely a pin 5) of the K4, so that the suction of the vacuum relays J1, J2, J3 and J4 is respectively controlled; the ends of IN1, IN2, IN3 and IN4 of the BSMU are respectively connected with the second common end (namely a pin 6) of the vacuum relays J1, J2, J3 and J4, and the feedback J1, J2, J3 and J4 are attracted and grounded; HV + and HV-ends of the BSMU are respectively connected with the anode and the cathode of the output end of the auxiliary power module to sample the voltage of the output end of the auxiliary power module, and CT, GND and +5V ends of the BSMU are connected with E3 to sample the current of the output end of the auxiliary power module; the temperature detection ends TEMP1 and TEMP2 of the BSMU are connected with the thermistor NTC1 in parallel to detect the temperature, an input power supply end adopts an ACC of 24V to supply power, and the BSMU is in communication connection with the battery cycle test screen through an RS232 interface.

As shown in fig. 8, the master _ battery PACK and the slave _ battery PACK are provided with a master _ current sampling module E1, namely LEM-900S, at the position BAT + of PACK18, which is the positive electrode of the master _ battery PACK, for sampling the current of the master _ battery PACK, and a slave _ current sampling module E2, namely LEM-900S, at the position BAT + of PACK28, which is the positive electrode of the slave _ battery PACK, for sampling the current of the slave _ battery PACK;

the testing method of the battery cycle tester comprises the following steps that a master-battery PACK charges a slave-battery PACK, and the slave-battery PACK charges the master-battery PACK:

the slave _ battery PACK charges the master _ battery PACK: clicking the number button on the battery cycle test display screen for even times, selecting the slave _ battery PACK to charge the master _ battery PACK, and then clicking the start button, wherein the AIR end of the BSMU outputs high level to the coil anode (pin 7) of the K5, the coil cathode (pin 8) is grounded, the K5 is clicked to close the common end I (pin 5) and the normally open contact I (pin 3), the common end II (pin 6) and the normally open contact II (pin 4), the CAN2 of the PLC control panel is in handshake communication with the slave _ BECU, the slave _ BECU sends a request voltage/current to the BMSU through CAN1 communication, the HVDC end of the BMSU outputs high level, the K3 is not clicked, the normally closed contact I (pin 1) is communicated with the common end I (pin 5), the coil anode (pin 7) of the J4 inputs high level, the coil cathode (pin 8) is grounded, the normally open of the J4 is controlled, and the contact II (pin 84) of the J4 is grounded, the common terminal two (pin 6) of J4 is connected to BSMU _ IN4 input test (i.e. pull ground for J4 pull-IN); the positive pole of the main _ battery PACK is connected to the positive pole of the input end of the bidirectional power module through J4, the negative pole of the input end of the bidirectional power module is connected with the negative pole of the main _ battery PACK, the slave _ BECU sends a request voltage/current to the BMSU _ CAN1 through CAN2 communication, the CH end of the BMSU outputs high level, K2 is not attracted, a normally closed contact I (namely pin 1) is communicated with a public end I (namely pin 5), the coil positive pole (namely pin 7) of J2 inputs high level, the coil negative pole (namely pin 8) is grounded, J2 is controlled to be attracted, a normally open contact II (namely pin 4) of J2 is grounded, and the public end II (namely pin 6) of J2 is connected to BSMU _ IN2 input detection (namely pulled to be attracted by J2); the PLC control board sends a request voltage/current to the bidirectional power module through CAN1 communication, the positive pole of the output end of the bidirectional power module returns to the positive pole of the slave _ battery PACK through J2, and the negative pole of the output end of the bidirectional power module is connected with the negative pole of the slave _ battery PACK, so that the master _ battery PACK charges the slave _ battery PACK;

the slave _ battery PACK charges the master _ battery PACK: clicking the number button odd times on the battery cycle test display screen, selecting the master _ battery PACK to charge the slave _ battery PACK, clicking the start button, outputting a high level from the AIR end of the BSMU to the coil anode (namely pin 7) of the K5, grounding the coil cathode (namely pin 8), not attracting the K5, closing the public end I (namely pin 5) and the normally closed contact I (namely pin 1), closing the public end II and the normally closed contact II (namely pin 2), performing CAN handshake communication between the PLC control board and the master _ BECU, sending a request voltage/current to the BMSU through CAN communication by the master _ BECU, outputting a high level from the AP end of the BMSU, not attracting the K4, communicating the normally closed contact I (namely pin 1) and the public end I (namely pin 5), inputting a high level from the coil anode (namely pin 7) of the J3, grounding the coil cathode (namely pin 8), controlling the J3 to attract, and controlling the normally open contact II (namely pin 4) of the J3 to ground, the common terminal two (pin 6) of J3 is connected to BSMU _ IN3 input test (i.e. pull ground for J3 pull-IN); the positive pole of the slave _ battery PACK is connected to the positive pole of the input end of the bidirectional power module through J3, the negative pole of the input end of the bidirectional power module is connected with the negative pole of the slave _ battery PACK, the master _ BECU sends a request voltage/current to the BMSU through CAN communication, the CTRL end of the BMSU outputs high level, K1 is not attracted, a normally closed contact I (namely pin 1) is communicated with a public end I (namely pin 5), the coil positive pole (namely pin 7) of J1 inputs high level, the coil negative pole (namely pin 8) is grounded, J1 is controlled to be attracted, a normally open contact II (namely pin 4) of J1 is grounded, and the public end II (namely pin 6) of J1 is connected to BSMU _ IN1 input detection (namely, the ground is pulled to attract for J1); the PLC control board sends a request voltage/current to the bidirectional power module through CAN communication, the anode of the output end of the bidirectional power module returns to the anode of the main _ battery PACK through J1, and the cathode of the output end of the bidirectional power module is connected with the cathode of the main _ battery PACK, so that the auxiliary _ battery PACK charges the main _ battery PACK;

the BMSU controls the charging and discharging loop only after detecting a charger connection confirmation signal, a master-battery PACK charging connection confirmation signal or a slave-battery PACK charging connection confirmation signal.

The test method also comprises hardware high-voltage interlocking: when the master-battery PACK charges the slave-battery PACK, because the HVDC end of the BMSU outputs a high level to control the J4 to attract, the IN4 inputs a low level to perform attraction feedback detection of J4, the second public end (namely the pin 6) of the J4 is grounded IN a closed mode, the negative coil (namely the pin 8) of the connected K4 is grounded, the positive coil (namely the pin 7) of the K4 is connected with 24V, the relay K4 attracts, the first public end (namely the pin 5) of the K4 is disconnected with the first normally-closed contact (namely the pin 1), the vacuum relay J3 is disconnected, and the vacuum relay J3 cannot be attracted by a BSMU given signal; because the CH end of the BMSU outputs high level to control J2 to be attracted, the IN2 inputs low level to be J2 attraction feedback detection, the second public end (namely a pin 6) of the J2 is grounded IN a closed mode, the negative pole (namely a pin 8) of the coil of the K1 which is connected with the second public end is grounded, the positive pole (namely a pin 7) of the coil of the K1 is connected with 24V, the relay K1 is attracted, the first public end (namely a pin 5) of the K1 is disconnected with the first normally closed contact (namely a pin 1), the vacuum relay J1 is disconnected, and the vacuum relay J1 cannot be attracted by a BSMU given signal;

when the main-battery PACK is charged from the _ battery PACK, the AP end of the BMSU outputs high level to control J3 to attract, the IN3 inputs low level to perform attraction feedback detection of J1, the second public end (namely a pin 6) of the J3 is grounded IN a closed mode, the negative coil (namely a pin 8) of the connected K3 is grounded, the positive coil (namely a pin 7) of the K3 is connected with 24V, the relay K3 attracts, the first public end (namely a pin 5) of the K3 is disconnected with the first normally-closed contact (namely a pin 1), the vacuum relay J4 is disconnected, and the vacuum relay J4 cannot be attracted by a BSMU given signal; because the CTRL end of the BMSU outputs a high level to control J1 to be attracted, the IN1 inputs a low level to be J1 attraction feedback detection, the second common end (namely a pin 6) of the J1 is grounded IN a closed mode, the negative pole (namely a pin 8) of the coil of the K2 connected with the ground is connected, the positive pole (namely a pin 7) of the coil of the K2 is connected with 24V, the relay K2 is attracted, the first common end (namely a pin 5) of the K2 is disconnected with the first normally closed contact (namely a pin 1), the vacuum relay J1 is disconnected, and the vacuum relay J1 cannot be attracted through a BSMU given signal;

therefore, when the master _ battery PACK charges the slave _ battery PACK or the slave _ battery PACK charges the master _ battery PACK, hardware high-voltage interlocking of J3 and J4 and hardware high-voltage interlocking of J1 and J2 can be realized, and the master _ battery PACK and the slave _ battery PACK cannot be discharged or charged at the same time, so that the safety of the battery cycle tester is guaranteed.

The battery cycle tester also has overcharge and overdischarge protection of a battery PACK monomer, BMUs are arranged in a master-battery PACK and a slave-battery PACK and are used for monitoring the voltage of the battery monomer in the battery PACK, the temperature, the SOC, the charge-discharge bidirectional balance and the like in real time, the service life of the battery is influenced by overhigh voltage of the battery monomer, and the upper limit voltage and the lower limit voltage are set by an upper computer.

When the slave _ battery PACK charges the master _ battery PACK, if the voltage of a certain battery cell of the slave _ battery PACK is too low and reaches the set lower limit voltage, the slave _ battery PACK is sent to the master _ BECU and the BSMU through the CAN communication (data information between the slave _ BECU and the master _ BECU is transferred and held by the CAN1 and the CAN2 of the BSMU), the AP end of the BSMU is at a low level, the vacuum relay J3 is disconnected, so that the bidirectional power module does not supply power and input, meanwhile, the BSMU sends a request voltage/current to the auxiliary power module through the CAN communication, and the auxiliary power module outputs the requested voltage/current from the power grid to continue to charge the master _ battery PACK through the J1; similarly, when the master-battery PACK charges the slave-battery PACK, if the voltage of a certain battery cell of the master-battery PACK is too low and reaches the set lower limit voltage, the J4 is disconnected, and the auxiliary power module outputs the requested voltage/current from the power grid to continue to charge the slave-battery PACK through the J2; the over-discharge protection of the battery PACK monomer is realized;

when the slave _ battery PACK charges the master _ battery PACK, if the voltage of a certain battery cell of the master _ battery PACK is too high and reaches the set upper limit voltage, the master _ battery PACK is sent to the slave _ BECU and the BSMU through the CAN communication (data information between the slave _ BECU and the master _ BECU is transferred and embraced through the CAN1 and the CAN2 of the BSMU), the CTRL end of the BSMU is at a low level, and the vacuum relay J1 is disconnected to cause the master _ battery PACK to stop charging; similarly, when the master _ battery PACK charges the slave _ battery PACK, if the voltage of a certain battery cell of the slave _ battery PACK is too high and reaches the set upper limit voltage, the J2 is disconnected, so that the slave _ battery PACK stops charging; and the overcharge protection of the battery PACK monomer is realized.

Charging directions can be switched on the upper computer and the battery cycle test screen, and the bidirectional power module and the auxiliary power module are provided with voltage/current through the upper computer, so that battery PACK cycle tests with different voltage and current requirements are met.

In summary, the battery cycle tester and the testing method thereof have the following advantages:

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations fall within the scope defined by the appended claims.

Claims

1. A battery cycle tester is characterized by comprising a master-battery PACK, a slave-battery PACK, a charging and discharging loop and a bidirectional power module, wherein the slave-battery PACK is a tested battery PACK, the charging and discharging loop comprises relays J1, J2, J3, J4, relays K1, K2, K3 and K4, the positive electrode of the slave-battery PACK is connected with a first common end of J3 and a first common end of J2 through a high-voltage switch, the positive electrode of the master-battery PACK is connected with a first normally-open contact of J4 and a first normally-open contact of J1, the first normally-open contact of J3 and the first common end of J4 are connected with the positive electrode of an input end of the bidirectional power module, and the first normally-open contact of J2 and the common end of J1 are connected with the positive electrode of an output end of the bidirectional power module; a second common end of the J3 is connected with a first normally closed contact of the K4, a second common end of the J3 is connected with a negative coil of the K3, a positive coil of the J3 is connected with a first normally closed contact of the K4, and a negative coil of the J3 and a second normally open contact of the J89are; a second common end of the J2 is connected with a first normally closed contact of the K2, a second common end of the J2 is connected with a negative coil of the K1, a positive coil of the J2 is connected with a first normally closed contact of the K2, and a negative coil of the J2 and a second normally open contact of the J89are; a second common end of the J4 is connected with a first common end of the K4, a positive electrode of the coil is connected with a first common end of the K3, and a negative electrode of the coil is grounded with a second normally-open contact; a second common end of the J1 is connected with a first common end of the K2, a positive electrode of the coil is connected with a first common end of the K1, and a negative electrode of the coil is grounded with a second normally-open contact; the positive poles of the coils of K1, K2, K3 and K4 are all connected with ACC, the normally closed contact of K1 is connected with the CTRL end of BSMU, the common end of K2 is connected with the CH end of BSMU, the normally closed contact of K3 is connected with the HVDC end of BSMU, and the common end of K4 is connected with the AP end of BSMU; the negative pole of the input end of the bidirectional power module, the negative pole of the output end of the bidirectional power module, the negative pole of the master-battery PACK and the negative pole of the slave-battery PACK are all connected, and the BSMU is a battery management unit and is in communication connection with the battery cycle test screen through an RS232 interface.

2. The battery cycle tester as claimed in claim 1, wherein the battery cycle tester further comprises a slave _ BECU, a master _ BECU, a PLC control board, and a relay K5, wherein the first common terminal and the second common terminal of the relay K5 are in CAN communication connection with the PLC control board, the negative electrode of the coil is grounded, the positive electrode of the coil is connected with the AIR terminal of the BSMU, the first normally closed contact and the second normally closed contact are in CAN communication connection with the master _ BECU, and the first normally open contact and the second normally open contact are in CAN communication connection with the slave _ BECU; the master _ BECU is in communication connection with the master _ battery PACK and the BMSU through a CAN, and the slave _ BECU is in communication connection with the slave _ battery PACK and the BMSU through the CAN; the PLC control board is in communication connection with the output end of the bidirectional power module through a CAN;

3. The battery cycling tester according to claim 2, further comprising an auxiliary power module having inputs IN3, IN4, IN5 connected to three-phase ac power of the grid, an input IN1 connected to a protection ground PE, an output having a positive terminal connected to a positive terminal of an output of the bi-directional power module, an output having a negative terminal connected to a negative terminal of an output of the bi-directional power module, and an output connected to the BSMU via CAN communication.

4. The battery cycling tester of claim 1, wherein the terminals IN1, IN2, IN3 and IN4 of the BSMU are respectively connected to the common terminals two of the relays J1, J2, J3 and J4 for pull-IN feedback detection of the corresponding relays.

5. The battery cycle tester of claim 3, wherein the positive pole and the negative pole of the output end of the bidirectional power module are respectively connected with the HV + and the HV-ends of the PLC control board; the positive pole OUT1 and the negative pole OUT4 of the output end of the auxiliary power module are respectively connected with the HV + and the HV-ends of the BSMU; the HV + and HV-ends of the main _ BECU are respectively connected with the positive electrode and the negative electrode of the main _ battery PACK; HV + and HV-terminals of the slave _ BECU are respectively connected with the positive electrode and the negative electrode of the slave _ battery PACK; for voltage sampling.

6. The battery cycle tester as claimed in claim 3, wherein the current sampling terminal of the master _ BECU is connected to a master _ current sampling module E1 located at the positive electrode of the master _ battery PACK, the current sampling terminal of the slave _ BECU is connected to a slave _ current sampling module E2 located at the positive electrode of the slave _ battery PACK, the current sampling terminal of the BSMU is connected to an auxiliary _ current sampling module E3 located at the positive electrode of the output terminal of the auxiliary power module, the current sampling terminal of the PLC control board is connected to a power module _ current sampling module E4 located between the positive electrode of the output terminal of the bidirectional power module and the charge-discharge loop, the master _ current sampling module, the slave _ current sampling module and the auxiliary _ current sampling module are all LEM-900S, and the power module _ current sampling module is CS400 ET.

7. The battery cycling tester of claim 3, wherein the bi-directional power module comprises parallel bi-directionally switched AC/DC modules REG75035, and the auxiliary power module comprises 1 bi-directionally switched AC/DC module REG 75035.

8. A method of testing a battery cycling tester according to any of claims 1-7, comprising the master _ cell PACK charging the slave _ cell PACK and the slave _ cell PACK charging the master _ cell PACK;

when the master _ battery PACK charges the slave _ battery PACK: selecting a master-battery PACK to charge a slave-battery PACK on a battery cycle test screen, controlling J4 attracting by BMSU through K3, controlling J4 the positive pole of the master-battery PACK to the positive pole of the input end of a bidirectional power module, connecting the negative pole of the input end of the bidirectional power module with the negative pole of the master-battery PACK, controlling J2 attracting by the BMSU through K2, returning the positive pole of the output end of the bidirectional power module to the positive pole of the slave-battery PACK through J2, and connecting the negative pole of the output end of the bidirectional power module with the negative pole of the slave-battery PACK to realize that the master-battery PACK charges the slave-battery PACK;

the slave _ battery PACK charges the master _ battery PACK: the method comprises the steps that a slave-battery PACK is selected to charge a master-battery PACK on a battery cycle test screen, a BMSU controls J3 to attract through K4, the positive pole of the slave-battery PACK is connected to the positive pole of the input end of a bidirectional power module through J3, the negative pole of the input end of the bidirectional power module is connected with the negative pole of the slave-battery PACK, the BMSU controls J1 to attract through K1, the positive pole of the output end of the bidirectional power module returns to the positive pole of the master-battery PACK through J1, the negative pole of the output end of the bidirectional power module is connected with the negative pole of the master-battery PACK, and the slave-battery PACK charges the master-battery PACK.

9. The method of claim 8, further comprising a hardware high voltage interlock, the hardware high voltage interlock comprising:

10. The method of claim 8, further comprising overcharge and overdischarge protection of the battery PACK cells: