Simulation multi-string battery pack monomer output circuit

Abstract

The utility model discloses a simulation multi-string battery pack monomer output circuit, which relates to the technical field of energy storage system detection and comprises a voltage reduction module and a plurality of simulation monomer cell voltage circuits connected in series. The voltage reduction module is used for reducing voltage of an external test power supply to supply power to the simulation single cell voltage circuit; the single cell voltage simulation circuit comprises an isolation power supply module and a reference power supply module; the isolation power supply module supplies power to the reference power supply module. The reference power supply module is used for simulating voltage output of the single cell; the reference power supply modules are connected in series, and the analog cells are connected in series. The circuit is applied to a BMS circuit test, simulates a battery pack to output a group of high-precision battery cell voltages, and compares the voltages acquired by the BMS with an output standard voltage to confirm whether a sampling error meets a standard or not, so that the performance of an AFE chip of the BMS and a related acquisition circuit can be effectively verified before leaving a factory, and the quality of a shipment product is ensured.

Description

TECHNICAL FIELD

[0001] The utility model relates to energy storage system detection technical field especially relates to a simulation multi -string battery package single output circuit. BACKGROUND

[0002] Due to the continuous enhancement of modern people's environmental protection consciousness, the energy storage field has also developed rapidly. The most important thing in the use process of energy storage equipment is safety, and the most fundamental factor for preventing safety risks is the accuracy of battery information. Only the BMS master can accurately read the state information of the battery to take protective measures for the battery in time, and if the error is too large, it will lead to overcharge and overdischarge, and even damage the battery or cause the battery to catch fire or explode.

[0003] The most critical of battery information is the cell voltage reading, because the total voltage data of the battery, SOC data, SOH data, and whether the battery can be charged or discharged depend on the voltage information of each cell in the battery pack. Therefore, the accuracy of the single cell voltage information is crucial, which is also a key indicator to measure the performance and quality of the BMS protection board.

[0004] Since BMS collects cell voltage using AFE chips and related collection circuits, if some AFE chips have reduced performance or the collection circuit is defective, the collection accuracy will be severely reduced. This phenomenon must be detected before shipment to ensure the quality of the shipped products.

[0005] Traditionally, a multi-stage resistance voltage dividing circuit is directly used to provide the voltage output of the cell series, but the voltage output has low precision and cannot effectively verify the performance of the AFE chip. INVENTION CONTENTS

[0006] The utility model discloses a kind of for simulating multi-string battery package single output circuit, which can be applied to the test process of BMS, simulates a group of high-precision cell voltage of battery package output, compares the voltage collected by BMS with output standard voltage to confirm whether sampling error meets standard or not. Technical scheme is as follows:

[0007] A kind of simulating multi-string battery package single output circuit, characterized by comprising: a voltage reduction module and a plurality of analog single cell voltage circuits in series;

[0008] The voltage reduction module is used to step down the external test power supply to power the analog single cell voltage circuit;

[0009] The analog single cell voltage circuit includes an isolated power supply module and a reference power supply module;

[0010] The isolated power supply module powers the reference power supply module;

[0011] The reference power module is used for simulating voltage output of a single cell;

[0012] The reference power modules are connected in series to simulate cell connection: the output negative pole of a previous reference power module is connected with the output positive pole of a next reference power module, and the output negative pole of a last reference power module is connected with the ground.

[0013] Further, the output voltage of the isolation power module is 5V.

[0014] Further, the reference power module comprises a controllable precision voltage stabilizing source chip and a configuration resistor.

[0015] Further, the controllable precision voltage stabilizing source chip is LM4040AIM3-3.0 or a compatible model thereof, and the configuration resistor has a precision not less than 0.01%.

[0016] Further, the reference power module further comprises an overcurrent protection device, and the reference power module outputs through the overcurrent protection device.

[0017] Further, the overcurrent protection device is a fuse type fuse.

[0018] Further, the reference power module further comprises a filter capacitor, and the filter capacitor is connected across the output positive pole and the output negative pole of the reference power module.

[0019] Further, the reference power module further comprises a transient voltage suppression tube, and the transient voltage suppression tube is connected across the output positive pole and the output negative pole of the reference power module.

[0020] Further, the step-down module adopts a BUCK type DC-DC circuit.

[0021] Further, the output voltage of the step-down module is 5V.

[0022] Compared with the prior art, the utility model has the remarkable characteristics that:

[0023] The circuit is applied to BMS circuit test, simulates a group of high-precision cell voltages output by a battery pack, and then compares the voltages with output standard voltages through BMS to confirm whether sampling error conforms to the standard, so that the performance of the AFE chip and the related acquisition circuit of the BMS can be effectively verified before delivery, and the quality of the delivery product is ensured. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 is a connection schematic diagram of a simulated multi-string battery pack single output circuit and a BMS;

[0025] Figure 2is a circuit schematic diagram of a voltage reduction circuit;

[0026] Figure 3 is a circuit schematic diagram of a single analog battery cell output circuit;

[0027] Figure 4 is a circuit schematic diagram of a plurality of battery cell output circuits in series. DETAILED DESCRIPTION

[0028] To further illustrate the embodiments, the utility model provides the drawings. These drawings are part of the utility model disclosure, which mainly serves to illustrate the embodiments, and can be combined with the relevant description of the specification to explain the operating principle of the embodiments. With reference to these contents, those skilled in the art should understand other possible implementations and the advantages of the utility model. The components in the drawings are not drawn to scale, and similar component symbols are usually used to represent similar components.

[0029] The utility model will be further illustrated in combination with the drawings and specific embodiments.

[0030] As Figure 1 shown, the utility model gives a kind of analog multi-string battery pack single output circuit, which is applied to multi-channel battery cell simulation board, and the battery cell simulation board is connected with the battery cell single voltage acquisition circuit of test power supply (switching power supply) and BMS, simulates a group of high-precision battery cell voltage, and then compares the voltage with output standard voltage to confirm whether sampling error meets standard, so that the performance of BMS AFE chip and related acquisition circuit can be effectively verified before factory, so as to guarantee the quality of outgoing product.

[0031] Specifically, the analog multi-string battery pack single output circuit is composed of a voltage reduction circuit and a plurality of analog single battery cell voltage circuits in series.

[0032] As Figure 2 shown, in the embodiment, BUCK type DC-DC circuit is used in voltage reduction circuit, and its input end is connected with test power supply;Voltage reduction circuit reduces the voltage of test power supply (also the power supply voltage of BMS, usually direct current 24V) and outputs to isolated power module for power supply. BUCK type DC-DC circuit has the characteristics of large input voltage range, high power conversion efficiency and low cost. In the embodiment, preferably, the output voltage of voltage reduction circuit is 5V.

[0033] As Figure 3 shown, analog single battery cell voltage circuit is composed of isolated power module, reference power module and the like.

[0034] In the embodiment, the isolation power module MOD2 adopts a 5V isolation power module, and the capacitor C17 is an output filter capacitor.

[0035] In the embodiment, the controllable precision voltage source U26 adopts an LM4040AIM3-3.0, and the configuration resistor R283 adopts a high-precision resistor with an accuracy of 0.01%, so that the output voltage of the U26 can reach an accuracy within 5mV. Since the collection accuracy of the AFE chip is ≤10mV, the output accuracy can be completely used as a test standard.

[0036] It should be noted that the controllable precision voltage source can also adopt a compatible model of LM4040AIM3-3.0.

[0037] In the simulated single cell voltage circuit, a transient voltage suppression tube D57 and a fuse F40 and the like are further included to provide circuit protection such as spike suppression and overcurrent protection.

[0038] In specific implementation, a battery pack is formed by a plurality of cells connected in series, so the simulated cell circuit also needs a plurality of simulated single cell voltage circuits connected in series. In this way, the collection accuracy of the multi-channel collection circuit of the BMS can be tested at the same time. The series circuit of the plurality of simulated single cell voltage circuits is as shown in Figure 4

[0039] It should be noted that the fuse F40 for providing overcurrent protection is preferably a fuse-type fuse with stable resistance and high consistency, which will not affect the voltage output accuracy of the simulated single cell voltage circuit in use.

[0040] In summary, compared with the prior art, the utility model has the following obvious characteristics:

[0041] The circuit is applied to BMS circuit testing, simulates a group of high-precision cell voltages output by a battery pack, and then compares the collected voltage with the output standard voltage to confirm whether the sampling error meets the standard, so that the performance of the AFE chip and the related collection circuit of the BMS can be effectively verified before leaving the factory, thereby ensuring the quality of the shipped products.

[0042] ​Although the present invention has been specifically shown and described in conjunction with preferred embodiments, those skilled in the art should understand that various changes in form and detail may be made to the present invention without departing from the spirit and scope of the present invention as defined in the appended claims, and all such changes shall be within the scope of protection of the present invention.

Claims

1. A circuit simulating the output of a single cell in a multi-cell battery pack, characterized in that, include: Step-down module and series-connected multi-channel analog single cell voltage circuit; The step-down module is used to step down the external test power supply to power the simulated single cell voltage circuit; The simulated single-cell voltage circuit includes an isolation power supply module and a reference power supply module; The isolated power supply module supplies power to the reference power supply module; The reference power module is used to simulate the voltage output of a single battery cell; The reference power modules are connected in series, simulating the series connection of battery cells: the negative output of the previous stage reference power module is connected to the positive output of the next stage reference power module, and the negative output of the last stage reference power module is grounded.

2. The analog multi-cell battery pack single-unit output circuit as described in claim 1, characterized in that, The output voltage of the isolated power supply module is 5V.

3. The analog multi-cell battery pack single-unit output circuit as described in claim 1, characterized in that, The reference power module includes a controllable precision voltage regulator chip and its configured resistors.

4. The analog multi-cell battery pack single-unit output circuit as described in claim 3, characterized in that, The controllable precision voltage regulator chip is LM4040AIM3-3.0 or a compatible model; the accuracy of the configuration resistor is not less than 0.01%.

5. The analog multi-cell battery pack single-unit output circuit as described in claim 1, characterized in that, The reference power module also includes an overcurrent protection device, and the reference power module outputs power after passing through the overcurrent protection device.

6. The analog multi-cell battery pack single-cell output circuit as described in claim 5, characterized in that, The overcurrent protection device is a fusible fuse.

7. The analog multi-cell battery pack single-unit output circuit as described in claim 1, characterized in that, The reference power supply module also includes a filter capacitor, which is connected between the positive and negative output terminals of the reference power supply module.

8. The analog multi-cell battery pack single-unit output circuit as described in claim 1, characterized in that, The reference power supply module also includes a transient voltage suppressor, which is connected between the positive and negative output terminals of the reference power supply module.

9. The analog multi-cell battery pack single-unit output circuit as described in claim 1, characterized in that, The step-down module uses a BUCK-type DC-DC circuit.

10. The analog multi-cell battery pack single-unit output circuit as described in claim 1, characterized in that, The output voltage of the step-down module is 5V.

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