TWI777471B - Intelligent battery string monitoring and charge-discharge control device and its measurement method - Google Patents

Abstract

The invention discloses an intelligent battery string monitoring and charge-discharge regulation device and a measurement method thereof. A plurality of batteries of the same type are connected in parallel to form a low-voltage and high-current battery pack by a multifunctional connecting line, and then connected to a dedicated independent battery pack. The charging device, and then connect the signal line of each multi-function cable to the corresponding signal input port of the battery string monitor to form a battery module that can independently charge and measure battery status (including voltage, current, and temperature). A set of (energy storage) battery management system is composed of bidirectional converter PCS; the number of battery module units will be based on the input rated voltage of the bidirectional converter PCS DC terminal used, and several groups of the above The battery module units are connected in series to meet the voltage range, so as to complete the construction of the (energy storage) battery management system.

Description

Intelligent battery string monitoring and charge-discharge control device and its measurement method

The present invention relates to a battery string regulating device and a measuring method, in particular to a battery string connected in parallel by a multi-function connecting line, and through the battery string monitor and the bidirectional converter PCS, it is possible to select collective charging or An intelligent battery string monitoring and charge-discharge control device capable of independent (individual) charging and capable of measuring battery status, and a measuring method thereof.

Today's rechargeable batteries are widely used in uninterruptible power systems, electric vehicles and other fields, so the total capacitance of retired batteries in the future is quite considerable, and many of them still have commercial value. In order to recycle the retired batteries, Chinese Patent Announcement No. M562492 proposes a multi-type battery pack and an energy storage system to which it is applied. It connects a plurality of batteries with different discharge characteristics in series or in parallel with each other through a plurality of battery connectors, and uses a battery management system (BMS) for distribution. Adjust the discharge rate of each battery in the multi-type battery pack 1, and perform voltage measurement, temperature measurement, charge-discharge current monitoring, state of charge (SOC) and state of health (SOH) estimation .

However, at present, if you want to measure the large charging and discharging current of each battery, it is necessary to install a Hall current transformer (CT) or a shunt (Shunt) at the positive or negative end of each battery. Such materials are expensive. , and the volume of the components is relatively large, and the utilization rate of space is relatively low. If you want to monitor each battery in the energy storage system, it will complicate the wiring during the equipment installation process, and also increase the manpower and time during maintenance. The cost is not economical for application in large systems.

The above is only for current measurement evaluation. To achieve simultaneous energy measurement of the temperature of each battery, temperature detection wiring and sensors must be attached to the current measurement, which will increase the cost and complexity of manufacturing and assembly, which will make the storage battery more complicated. It becomes impractical for the energy system to trace the status of each battery. The main purpose of the present invention is to complete the state detection scheme for the current and temperature of each battery in a relatively simple manner.

The main purpose of the present invention is to provide an intelligent battery string monitoring and charge-discharge control device and a measurement method thereof, which has a multi-functional connecting wire for connecting to the battery. In addition to the current wiring requirements, the battery string monitor can also measure the tiny voltage at both ends of the wire, and then convert it into charging or discharging current, so as to understand the storage capacity and remaining power of the monitored battery, so as to accurately grasp the battery management. the goal of.

The secondary purpose of the present invention is to provide an intelligent battery string monitoring and charge/discharge control device and its measurement method. Both ends of the multi-function connecting line are connected with a temperature sensing resistor, and the internal loop of the battery string monitor In addition to measuring the current, it can also measure the temperature sensing resistance value at both ends of the multi-functional connecting line in time-sharing; and then convert the measured resistance value into the current contact of the multi-functional connecting line. point temperature, and then analyze the abnormal temperature of the monitored battery due to old damage or poor contact of the contact point; the temperature data can not only be used as a warning of abnormal state, but also can be used to correct the current temperature compensation for this section. , to improve the accuracy of the above current measurement value.

Another object of the present invention is to provide an intelligent battery string monitoring and charge-discharge control device and its measurement method, which have a mechanism to ensure that each battery is not charged; the energy storage system is equipped with a bidirectional converter in order to increase the supply voltage. (Power Conversion System, PCS) operating voltage, so it is necessary to connect multiple battery packs in series, but if the batteries are connected in series, the batteries will have uneven capacity, and some batteries with small capacity are prone to overcharge. In particular, the difference in capacity of retired or old batteries is more obvious, so it is more prone to local uneven charging and overcharging, and overcharging can easily increase the battery capacity gap and accelerate battery deterioration. In order to solve the situation of battery overcharge, the present invention is equipped with a dedicated independent charging device in each unit battery pack. In other words, the bidirectional converter PCS provides a single current to charge each unit battery collectively during charging. The control of the present invention It monitors the voltage of each unit battery pack, appropriately regulates the dedicated independent charging device corresponding to the battery pack with lower voltage, and applies compensatory charging, that is, through the mechanism of individual charging, to achieve the It can be fully charged, and it is guaranteed that the battery will not be overcharged.

Another object of the present invention is to provide an intelligent battery string monitoring and charge-discharge control device and its measurement method, which have a mechanism to ensure that each battery will not be over-discharged during the discharge process; In the mode, the battery string monitor of the present invention will monitor the voltage of each unit battery pack, and appropriately regulate the battery pack where the lower voltage is located, and the corresponding dedicated independent charging device will perform compensatory charging, that is, by means of compensatory charging. The mechanism of individual compensation is used to achieve the purpose of preventing over-discharge of battery packs with lower capacity during the discharge process, reducing the impact of uneven battery capacity on the overall energy storage system, and improving the discharge efficiency of the energy storage system.

Another object of the present invention is to provide an intelligent battery string monitoring and charge-discharge control device and its measurement method, which can achieve the effects of battery polarity activation and battery life extension, that is, in the charging mode, the battery string monitor can monitor The status information of each battery, adjust the charging current, balance the charging of the battery pack, and slow down the increase of the difference in the power of each battery; when the battery is approaching full charge, the battery string monitor controls the dedicated independent of each battery pack. The charging device uses pulse charging to activate the polarity of the battery, slow down the aging speed of the battery, and achieve the purpose of extending the service life of the battery.

The intelligent battery string monitoring and charge-discharge control device and its measurement method of the present invention can select different charging sources and mechanisms according to the requirements of the operating situation in the charging mode, such as (1) using the bidirectional converter PCS itself The charging mechanism is used to collectively charge all the battery module units at the DC end; or (2) the battery module units can be charged individually by using the independent charging device dedicated to each battery module unit. In the charging mode, the system can perform balanced charging more flexibly, so that each group of batteries can be balanced and fully charged.

In the discharge mode, when the depth of discharge (DOD) reaches a certain level, and the battery module begins to appear unbalanced, you can choose to control each battery module unit by controlling the dedicated independent charging device in each battery module unit. Individual power compensation is performed to achieve balance control before the end of discharge and prevent over-discharge of the battery.

During the above charging and discharging process, the device can grasp the capacity and temperature of each battery, and can accurately indicate the battery with too small capacity or abnormal temperature, which makes battery management more efficient and operation and maintenance easier. In the standby mode (or charging mode), the device can individually control the charging transient frequency of the dedicated independent charging device, and perform pulse charging on the battery, increasing the probability of activating the polarity of the battery to achieve the effect of prolonging the battery life.

The technical features, structures, methods and other functions and purposes of the present invention are described in detail as follows with reference to the accompanying drawings:

Referring to FIG. 2 and FIG. 3 , it is an intelligent battery string monitoring and charge-discharge control device of the present invention, and a preferred specific embodiment thereof includes: a multi-functional connecting cable 1 with special functions, a battery string monitor 2 , Combined with a dedicated independent charging device 3.1 and a bidirectional converter (PCS) 3.2, by connecting a certain number of batteries #1, #2 to #N-1, and #N in series and parallel, an intelligent battery string monitoring and charging system is constructed. A system of discharge control devices.

Referring to FIG. 1A and FIG. 1B , it is a schematic diagram of the power electronic structure and the external structure of the multi-function connection cable 1 in the present invention. FIG. 6A is an exploded schematic diagram of an embodiment of the multi-function connection cable of the present invention, and FIG. 6B is the temperature measurement in FIG. 6A . An exploded schematic view of a structural embodiment; a preferred embodiment of the multifunctional connecting wire 1 has a copper wire 1.3, and the two ends of the copper wire 1.3 are respectively connected to a high-current-resistant terminal 1.1, and the high-current-resistant terminals 1.1 are respectively used for connection. Between the above-mentioned batteries (as shown in FIG. 3 ); in particular, the present invention utilizes both ends of the multifunctional connecting wire 1 to connect a temperature sensing element 1.2 respectively, so that the multifunctional connecting wire 1 is applied in the The control device of the invention has functions such as measuring current signals and temperature signals; as shown in FIG. 6B , a specific embodiment of the temperature sensing element 1.2 includes a sensing wire 1.2.1 and a temperature sensing resistor 1.2. 2. A temperature sensing interface element 1.2.3 and a signal monitoring line 1.2.4, the temperature sensing resistor 1.2.2 is connected to the temperature sensing interface element 1.2.3 through the sensing medium wire 1.2.1 The two ends of the copper wire 1.3 are interfaced and fixed, and then the other ends of the temperature sensing resistors 1.2.2 on both sides are connected to a signal monitoring line 1.2.4 respectively, and the present invention has both the measurement current signal and the temperature signal. Functional multi-function cable 1.

The above-mentioned copper wire 1.3 is preferably a copper wire with a wire diameter of 38 mm², a wire length of 20 cm, and an impedance of about 0.1 mΩ, which is matched with the battery string monitor 2 to form the device of the present invention. Among them, the multi-function connecting line 1 will generate a voltage corresponding to the current when a current flows. Because of its extremely small resistance value, the corresponding voltage generated is also extremely small, so the battery string monitor 2 must have a good Stability and sensitivity can accurately measure the charging or discharging current flowing through the multi-function cable. At the same time, by means of the temperature monitoring structure designed on the multi-function connection cable 1, the same multi-function connection cable 1 can be used to measure the temperature at both ends of the multi-function connection cable 1, so as to know whether the temperature of the battery is abnormal or the connection at the connection is poor. , and perform temperature compensation for current measurement, so that battery management can be accurately traced to the charge and discharge current, power, storage capacity and temperature of each battery. For battery management, especially the management of retired batteries, the present invention The multi-function cable 1 provides better measurement key technology.

Figure 3 shows the installation form of the multi-functional connecting wire 1 of the present invention. One end of the multi-functional connecting wire 1 is connected to the negative electrode of the battery under test, and the other end is connected to the positive electrode of the next battery; if the battery under test is a whole string For the last battery, the multifunctional connecting line 1 connects the negative pole of the last battery with the negative pole of the overall system, so that the overall system forms a complete loop. After completing the series and parallel connection between the batteries through the multi-function connection line 1, the signal monitoring lines 1.2.4 on the multi-function connection line 1 passing through the temperature sensing resistor 1.2.2 are respectively connected to the battery string monitor 2 The corresponding signal measurement terminal completes the connection of the battery state monitoring line. As shown in FIG. 2 , each battery string monitor 2 can monitor the status of multiple batteries at the same time. In the embodiment of the present invention, one battery string monitor 2 is designed to monitor the status of 8 batteries simultaneously.

Referring to FIGS. 2 , 4 and 7 , the following describes the structure of the multifunctional cable 1 of the present invention with the battery string monitor 2 , the battery string monitor 2 mainly has an upper cover 2.1 , a monitoring board 2.2 and A base 2.3. First of all, the above-mentioned multi-function connecting line 1 is connected with the negative electrodes #1~#N of the corresponding batteries, and then the batteries #1~#N are connected in parallel through the copper bars. The positive and negative electrodes of the parallel batteries are independent of the dedicated battery. The charging device 3.1 is connected; after that, connect the two signal monitoring lines 1.2.4 on the multifunctional connecting line 1 of each battery negative pole to the monitoring board 2.2 of the battery string monitor 2 (as shown in Figure 7), The battery string monitor 2 is connected with the communication control line to a dedicated independent charging device 3.1 to form a group of parallel battery packs that can be monitored, and then each group of parallel battery packs (group 1 to group N in Figure 2) are connected in series Until the total DC voltage conforms to the rated voltage of the DC terminal of the bidirectional converter (PCS) 3.2, the complete construction of the entire system of the present invention is completed.

4 and the circuit diagram of FIG. 5A , the structure and operation principle of the multi-function cable 1 and the battery string monitor 2 of the present invention will be described below; P1 inputs 24V DC power to the DC power conversion circuit 4.1; then the components U1 and U3 in the DC power conversion circuit 4.1 and the Q1 element in the reference voltage supply circuit 4.3 are converted into 5V, 12V, 5.3V DC voltages to supply the battery respectively The internal components of the string monitor 2 are used for operation, and the reference voltage supply circuit 4.3 will stabilize a set of reference voltage REF1 through the U6 component, and provide it to the components of the electrical signal measurement circuit 4.5 for use. The following describes the measurement method of the battery string monitor 2 with the multi-function cable 1:

(1) Voltage measurement method: The positive electrode of the battery BAT (or the positive bus bar of the parallel battery pack) is connected to the electrical signal measurement circuit 4.5 of the battery string monitor 2 through the signal monitoring line mentioned above (as shown in Figure 5C) The J10 input connector element in the middle; the reference zero potential point is connected to the other end of the negative electrode of the battery BAT (or the negative bus bar of the parallel battery pack) from the multi-function connecting line 1, and is connected to the telecommunications shown in Figure 5C through the signal monitoring line. The J11 input connector element in the No. measurement circuit 4.5; the battery voltage signal is divided into the voltage ratio range of 0-5V through the R12, R13, R14, R15 high-impedance voltage divider measurement structure, and then passed through Figure 5C The J9 element of the electrical signal measurement circuit 4.5 is interconnected with the microcontroller and the J4 element of the control and display circuit 4.4 shown in FIG. 5A to conduct the divided voltage signal to the U7 and U8A elements of the electrical signal measurement circuit 4.5 in FIG. 5B Perform digital analog conversion, and then input it into the microcontroller and control display circuit 4.4 The microcontroller U11 element performs signal operation processing. After the microcontroller U11 calculates the monitoring signal, the data of the battery voltage monitoring is overwritten and stored in the U12 storage element , the voltage measurement operation is completed.

(2) Current and temperature measurement method: monitor the battery loop current through the multi-function connecting line 1 connected to the negative electrode of the battery BAT (or the negative bus bar of the parallel battery pack); during the charging process, the current flows through the multi-function The connecting line RW (as shown in Figure 1A) will generate a set of corresponding voltages, which are connected to the signal monitoring line 1.2.4 of the battery string monitor 2 to guide the electrical signal generated by the current to the electrical signal measuring circuit 4.5 in Figure 5C. The J1~J8 connector components, and then control the U1, U4, U6, U8 switching components by the U2, U5 control IC in the electrical signal measurement circuit 4.5, and switch to select the current signal source to be measured at the moment, and conduct the electrical signal through U3. Amplify and filter, and then connect to the microcontroller in Figure 5A and the J4 connector of the control display circuit 4.4 through the J9 connector to guide the current signal to the analog-to-digital conversion circuit composed of U10 and U8B in Figure 5B. After conversion The signal is input into the microcontroller in Figure 5B and the U11 microcontroller and the U12 storage element in the control display circuit 4.4 to calculate and store the current signal. After the current measurement is completed, switch to the next group of batteries and perform the current measurement with the above actions .

In the above-mentioned cycle monitoring process, the temperature of the terminals of the multi-function connecting lines with each battery will be switched to measure the temperature of the terminals of the multi-function connecting lines of each battery. By controlling the Q1 element in Figure 5C to drive the RY1 microswitch to switch, it will switch to the cycle measurement of each multi-function cable. The temperature of the functional connection line 1; the measurement method is that after the RY1 is switched, the REF1, R1, R2 of the electrical signal measurement circuit 4.5 will form a voltage divider structure with the Rt1, Rt2 temperature resistors in Figure 1A to generate a voltage signal corresponding to the temperature change, Then, the temperature signal to be measured is switched by the U7 switching element and input to the electrical signal measurement circuit. 4.5 The microcontroller U11 calculates the temperature data and stores it in the U12 storage element to complete the temperature measurement of the multi-function cable 1. After the temperature measurement is completed , and then control RY1 to switch the signal measurement source back to the current signal; through the above method, the signal source of the round-robin monitoring is switched over time to complete the current and temperature monitoring.

(3) Auxiliary control of the dedicated independent charging device 3.1, the control of the dedicated independent charging device 3.1 in the present invention is to perform command operations on the battery string monitor 2 through the external serial communication method, and the battery string tester 2 is matched with a Controllable dedicated independent charging device 3.1 to achieve the control of auxiliary charging and battery life extension; external devices that can carry out RS485 serial communication such as personal computer, industrial computer, server, SCADA, PLC, etc. can be used. The J2 connector elements of the shown DC power conversion circuit 4.1 are connected together to input the action command signal to be executed, and the signal is input to the microcontroller and the control display circuit 4.4 through the U2 serial communication isolation element of the serial communication circuit 4.2. The microprocessor U11 performs signal conversion, and controls the output signal of the microcontroller and the U16 and U17 optical isolation switch elements of the control display circuit 4.4 to control the dedicated independent charging device 3.1 in 3.1 in Figure 4. The signal output by U16 can control the dedicated independent charging device 3.1. When the independent charging device 3.1 is turned on and off, the signal output by U17 can adjust the output power of the dedicated independent charging device 3.1.

To sum up, the present invention has practicability and creativity, and the application of its technical means is undoubtedly novel, and the efficacy and design purpose are indeed consistent, which has been called a reasonable progress. To this end, I have filed an application for an invention patent according to the law, but I implore the Jun Bureau to give me a detailed review and grant the patent for my prayers.

1: Multifunctional cable 1.1: High current resistance terminal 1.2: Temperature sensing element 1.2.1: Sensing dielectric wiring 1.2.2: Temperature Sensing Resistor 1.2.3: Temperature Sensing Interface Components 1.2.4: Signal Monitoring Line 1.3: Copper wire 2: Battery string monitor 2.1: Top cover 2.2: Monitoring Board 2.3: Base 3.1: Dedicated independent charging device 3.2: Bidirectional converter 4.1: DC power conversion circuit 4.2: Serial communication circuit 4.3: Reference voltage supply circuit 4.4: Microcontroller and control display circuit 4.5: Electrical signal measurement circuit #1, #2~#N-1, #N: Battery

[FIG. 1A] is a schematic diagram of the structure of the electronic circuit element of the multifunctional connecting line of the present invention. [FIG. 1B] is a schematic diagram of the external structure of the embodiment of the multifunctional connecting line of the present invention. [FIG. 2] is a system block diagram of the intelligent battery string monitoring and charge-discharge control device system of the present invention. [FIG. 3] is a schematic diagram of the implementation of the multifunctional connecting line and the battery string monitor of the present invention. 4 is a functional block diagram of the battery string monitor of the present invention. [FIG. 5A~FIG. 5C] are circuit diagrams of embodiments of the battery string monitor in the present invention. 6A is an exploded schematic view of an embodiment of the multifunctional connecting line of the present invention. [FIG. 6B] is an exploded schematic view of the embodiment of the temperature measurement structure in FIG. 6A. 7 is an exploded schematic view of the battery string monitor of the present invention.

1: Multifunctional cable

2: Battery string monitor

3.1: Dedicated independent charging device

3.2: Bidirectional converter

#1, #2~#N-1, #N: Battery

Claims (7)

An intelligent battery string monitoring and charge-discharge control device includes a multi-functional connecting wire, the multi-functional connecting wire is used to connect two batteries to conduct current, and measure the current signal and the temperature signal; the multi-functional connection wire The wire has a copper wire, the two ends of the copper wire are respectively connected to a high-current terminal, the high-current terminal is respectively used to connect between the two batteries, the two ends of the copper wire or the high-current terminal are respectively connected to a temperature A sensing element; the temperature sensing element has a temperature sensing resistor, one end of the temperature sensing resistor is connected to the copper wire, the other end of the temperature sensing resistor is connected to a signal monitoring line, and the signal monitoring line is used for connecting a battery pack string monitor. The intelligent battery string monitoring and charge-discharge control device as claimed in claim 1, wherein the temperature sensing element comprises a sensing interface wire, a temperature sensing interface element and a signal monitoring wire; the temperature sensing resistor The sensing medium wire and the temperature sensing medium element are connected and fixed at both ends of the copper wire, and then a signal monitoring wire is respectively connected from the other end of the temperature sensing resistor at both ends of the copper wire. The monitoring line is used to connect the battery string monitor for voltage measurement, high current measurement, temperature measurement, and current temperature compensation. An intelligent battery string monitoring and charge-discharge control device, comprising the intelligent battery string monitoring and charge-discharge control device described in claim 1 or 2, wherein the multi-function connecting line is connected in parallel with a plurality of batteries, and a plurality of batteries The string monitor and a dedicated independent charging device; the multi-function connecting line is connected to the negative electrode of the corresponding battery to be measured, and then each battery is connected in parallel through the copper bar, and the positive and negative electrodes of the parallel battery are connected in parallel. Connect with the dedicated independent charging device; then connect the two signal monitoring lines on the multi-function connection line of each negative pole of the battery to the battery string monitor; the battery string monitor is also connected with a communication control line to the dedicated battery string monitor. Independent charging device, thereby forming a group of parallel battery packs that can be monitored. The intelligent battery string monitoring and charge-discharge regulating device as claimed in claim 3, further comprising a bidirectional converter (PCS) for connecting each of the parallel battery strings in series to a total DC voltage consistent with the bidirectional converter (PCS) DC terminal rated voltage. A measurement method for an intelligent battery string monitoring and charge-discharge control device as claimed in claim 3, comprising a voltage measurement method, which performs the following steps: the positive electrode of the battery or the positive bus bar of the parallel battery group, Connected to the input connector element of the electrical signal measurement circuit of the battery string monitor through a signal monitoring line; the reference zero potential point is connected to the other end of the negative electrode of the battery from the multi-function connecting line or the negative electrode of the parallel battery pack is busted The copper bar is connected to another input connector element of the electrical signal measurement circuit of the battery string monitor through another signal monitoring line; the voltage signal of the battery or the parallel battery group is measured by a high impedance voltage divider. The voltage signal is divided in the voltage ratio range of 0-5V; then the divided voltage signal is conducted to an electric signal measurement circuit through an electric signal measurement circuit, a microcontroller and a control display circuit connected to each other. The digital analog conversion is carried out by the measurement circuit; after that, it is input to the microcontroller and a microcontroller element that controls the display circuit for signal operation processing. After the microcontroller calculates the monitoring signal, the data of the battery voltage monitoring is overwritten and stored. In a storage element, the voltage measurement operation is completed. A measurement method for an intelligent battery string monitoring and charge-discharge control device as claimed in claim 3, comprising a current measurement method, which performs the following steps: during the charging process of the battery or the parallel battery pack, a current flows through the battery The multi-function connecting line generates a set of corresponding voltages, and by connecting to the signal monitoring line of the battery string monitor, the electrical signal generated by the current is guided to the connector element of an electrical signal measuring circuit; and then the electrical signal is used to measure The control IC of the circuit controls the switching element to switch and select the current signal source to be measured in turn, and then amplifies and filters the electrical signal, and then guides the current signal to an analog-to-digital conversion circuit through a microcontroller and a control display circuit. The converted signal is input into the microcontroller and a microcontroller that controls the display circuit and a storage element to calculate and store the current signal; and after the current measurement is completed, switch to the next group of batteries, and perform the above actions Current measurement. The measurement method of the intelligent battery string monitoring and charge-discharge control device as described in claim 6, further includes a temperature measurement method, which is to switch the measurement in accordance with the cycle period of the measurement battery during a cycle of monitoring. The terminal temperature of the multi-function cable with each battery is measured by the micro- Type switch switch, switch to measure the temperature of each multi-function connection line in turn, and perform the following steps: When the micro switch is switched, the electrical signal measurement circuit will form a voltage divider structure with the temperature sensing resistor to generate a corresponding The voltage signal of the temperature change is then switched to the temperature signal to be measured by the switching element in a time-sharing manner, and is input to a microcontroller of the electrical signal measurement circuit to calculate the temperature data, and then stored in a storage element to complete the multi-function connection. After the temperature measurement is completed, the signal measurement source is switched back to the current signal, and the signal source of the polling monitoring is switched over time by the above method to complete the current and temperature measurement.

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