A DC power calculation device and method

Abstract

The embodiment of the present invention discloses a direct current power calculation device and method. The direct current power calculation device formed by integrating a voltage detection unit, a data processing unit, a high-voltage isolation unit and a power processing unit is electrically connected to a high-voltage battery pack, and the weak voltage signal generated by the voltage detection unit is processed into a target digital signal by the data processing unit, and the target power calculation of the high-voltage battery pack is completed by current integration, and then the target power is sent to the main control unit of the battery pack management system of the high-voltage battery pack, so that high-speed and high-precision current collection and power calculation functions are realized, so that the main control unit of the battery pack management system can timely grasp the power status of the high-voltage battery pack; and the high-voltage isolation unit isolates the high-voltage side from the low-voltage safety side, and its withstand voltage value can reach AC5000Vrms, which further ensures the safety of equipment and personnel, and can provide a low-cost, highly stable and easy-to-use direct current power calculation device.

Description

Technical Field

[0001] The present invention relates to the field of battery technology, and in particular to a direct current electric quantity calculation device and method. Background Art

[0002] A battery is an energy storage device that can convert chemical energy into electrical energy. With the development of new battery technology, batteries have been applied to all walks of life. At present, shield machines are used in the construction of subway tunnels in my country. The slag generated during the excavation process is transported to the wellhead by the tunnel horizontal transport locomotive, and construction materials such as pipe segments and mortar are transported from the wellhead to the inside of the tunnel by the tunnel horizontal transport locomotive. The battery system provides power to the tunnel horizontal transport locomotive to drive the tunnel horizontal transport locomotive.

[0003] Due to the high voltage and wide output current range of the battery system, current collection and power calculation are difficult. At present, the existing technology uses Hall sensors to collect current. The Hall sensor converts the current signal into a voltage signal through magnetic induction technology and transmits it to the collection module through wires. Due to the limited sampling accuracy of the Hall sensor, the analog signal is easily interfered when transmitted through the wire, resulting in limited current collection accuracy and large deviation in battery system power calculation. Summary of the invention

[0004] The main purpose of the present invention is to provide a direct current power calculation device and method, which can solve the problems of limited current acquisition accuracy and large deviation in battery system power calculation in the prior art.

[0005] To achieve the above-mentioned object, the first aspect of the present invention provides a DC power calculation device, the device comprising: a voltage detection unit, a data processing unit, a high-voltage isolation unit and a power processing unit; wherein the output end of the voltage detection unit is electrically connected to the input end of the data processing unit, the output end of the data processing unit is electrically connected to the high-voltage side input end of the high-voltage isolation unit, the output end of the power processing unit is electrically connected to the low-voltage side input end of the high-voltage isolation unit, and the voltage detection unit, the data processing unit, the high-voltage isolation unit and the power processing unit are integrated into one body to form the device, and the device is connected in series with a high-voltage battery pack;

[0006] The high-voltage battery pack is used to store energy and is a calculation target of the DC power calculation device;

[0007] The voltage detection unit is used to detect a weak voltage signal corresponding to the current at both ends of the high-voltage battery pack;

[0008] The data processing unit is used to perform signal conversion on the weak voltage signal to obtain a target digital signal of the high-voltage battery pack and a target power corresponding to the target digital signal, and transmit the target power to a main control unit of a battery pack management system of the high-voltage battery pack, wherein the target digital signal is a digital signal corresponding to the weak voltage signal;

[0009] The high-voltage isolation unit is used to isolate and protect the high-voltage side from the low-voltage side, the high-voltage side is one side of the high-voltage isolation unit where the high-voltage battery pack is located, and the low-voltage side is the other side relative to the high-voltage side;

[0010] The power processing unit is used to stabilize the voltage input by the external power supply and provide stable power supply to the device.

[0011] A second aspect provides a DC power calculation method, the method being applied to the DC power calculation device according to any one of claims 1 to 6, the method comprising:

[0012] Acquire a weak voltage signal detected by a voltage detection unit;

[0013] Performing signal conversion on the weak voltage signal to obtain a target digital signal, wherein the target digital signal is a digital signal corresponding to the weak voltage signal;

[0014] Obtaining a target power of the high-voltage battery pack according to the target digital signal and a preset power algorithm;

[0015] The target power is transmitted to a main control unit of a battery pack management system of the high-voltage battery pack.

[0016] The embodiments of the present invention have the following beneficial effects:

[0017] The present invention provides a direct current electricity quantity calculation device, which includes: a voltage detection unit, a data processing unit, a high-voltage isolation unit and a power processing unit; wherein the output end of the voltage detection unit is electrically connected to the input end of the data processing unit, the output end of the data processing unit is electrically connected to the high-voltage side input end of the high-voltage isolation unit, the output end of the power processing unit is electrically connected to the low-voltage side input end of the high-voltage isolation unit, and the voltage detection unit, the data processing unit, the high-voltage isolation unit and the power processing unit are integrated into one to form the direct current electricity quantity calculation device, and the direct current electricity quantity calculation device is connected in series with a high-voltage battery pack. A DC power calculation device is formed by integrating a voltage detection unit, a data processing unit, a high-voltage isolation unit and a power processing unit, and electrically connected to a high-voltage battery pack. The weak voltage signal generated by the voltage detection unit is processed into a target digital signal by the data processing unit, and current integration is used to complete the target power calculation of the high-voltage battery pack, and then the target power is sent to the main control unit of the battery pack management system of the high-voltage battery pack, thereby realizing high-speed and high-precision current collection and power calculation functions, so that the main control unit of the battery pack management system can timely grasp the power status of the high-voltage battery pack; and the high-voltage isolation unit isolates the high-voltage side from the low-voltage safety side, and its withstand voltage value can reach AC5000Vrms, further ensuring the safety of equipment and personnel, and realizing a low-cost, highly stable and easy-to-use DC power calculation device. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] in:

[0020] Figure 1 A schematic diagram of an application environment of a DC power calculation device according to an embodiment of the present invention;

[0021] Figure 2 A schematic diagram of a flow chart of a method for calculating direct current electricity quantity in an embodiment of the present invention;

[0022] Figure 3 A schematic diagram of another application environment of a DC power calculation device according to an embodiment of the present invention;

[0023] Figure 4 Another schematic diagram of a flow chart of a method for calculating direct current electricity quantity according to an embodiment of the present invention;

[0024] Figure 5Schematic diagram of a function curve of a linear fitting function of a preset temperature and resistance in an embodiment of the present invention. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] See also Figure 1 , Figure 1 FIG. 1 is a structural block diagram of an application environment of a DC power calculation device according to an embodiment of the present invention. Figure 1 The DC power calculation device 100 shown includes: a voltage detection unit 102, a data processing unit 103, a high-voltage isolation unit 104 and a power processing unit 105; wherein, the output end of the voltage detection unit 102 is electrically connected to the input end of the data processing unit 103, the output end of the data processing unit 103 is electrically connected to the high-voltage side input end of the high-voltage isolation unit 104, the output end of the power processing unit 105 is electrically connected to the low-voltage side input end of the high-voltage isolation unit 104, and the voltage detection unit 102, the data processing unit 103, the high-voltage isolation unit 104 and the power processing unit 105 are integrated into a whole to form the DC power calculation device 100, and the DC power calculation device 100 is connected in series with the high-voltage battery pack 101.

[0027] It should be noted that the high-voltage battery pack 101 is used to store energy and is the calculation target of the DC power calculation device 100. The high-voltage battery pack 101 is an energy storage device composed of one or more battery packs and corresponding accessories, wherein the corresponding accessories include but are not limited to a battery pack management system, a high-voltage circuit, a low-voltage circuit, a thermal management system, and a mechanical assembly, etc. The DC power calculation device 100 is used to calculate the target power of the high-voltage battery pack 101 to better control the power status of the high-voltage battery pack 101.

[0028] Among them, the battery pack management system is used to monitor the battery power, total voltage, single cell voltage, total current, temperature, insulation resistance, charge state, power state and other status information, and provide communication, safety, cell balancing and management control for the battery, and provide a system for communication interface with application equipment.

[0029] The voltage detection unit 102 is used to detect a weak voltage signal corresponding to the current at both ends of the high-voltage battery pack 101 .

[0030] It should be noted that the voltage detection unit 102 includes but is not limited to current sensors such as shunts. The DC power calculation device 100 is connected in series with the high-voltage battery pack 101. When the current in the high-voltage battery pack 101 changes, the current inside the voltage detection unit 102 will change at the same time, thereby generating a voltage. According to Ohm's law, a weak voltage signal can be obtained.

[0031] Exemplarily, the resistance of the shunt is 100 μΩ, and the sampling accuracy is 0.01 A, so the corresponding voltage is 1 μV, so that the current across the high-voltage battery pack 101 detected by the shunt corresponds to a weak voltage signal.

[0032] The data processing unit 103 is used to perform signal conversion on the weak voltage signal to obtain the target digital signal of the high-voltage battery group 101 and the target power corresponding to the target digital signal, and transmit the target power to the main control unit of the battery group management system of the high-voltage battery group 101. The target digital signal is a digital signal corresponding to the weak voltage signal.

[0033] In a feasible implementation, the signal conversion includes but is not limited to signal acquisition, signal filtering, analog-to-digital conversion, and power calculation.

[0034] It is understandable that after obtaining the target power, the target power signal can be transmitted to the main control unit of the battery pack management system of the high-voltage battery pack 101, so that the performance and operating parameters of the high-voltage battery pack 101 can be effectively and real-time managed.

[0035] The high voltage isolation unit 104 is used to isolate and protect the high voltage side and the low voltage side. The high voltage side is one side of the high voltage isolation unit 104 where the high voltage battery pack 101 is located, and the low voltage side is the other side relative to the high voltage side.

[0036] It should be noted that the voltage range of the high-voltage battery pack is as high as 400-750V, and the current output range is as high as ±800A. Since the battery system voltage is high and the output current range is wide, the total voltage of the battery system is as high as 750V, which is harmful to operators and low-voltage equipment. Therefore, a high-voltage isolation unit 104 is set to achieve isolation protection between the high-voltage dangerous side and the low-voltage safe side to ensure power safety.

[0037] Exemplarily, the high-voltage isolation unit 104 includes but is not limited to using an electromagnetic isolation method for isolation protection, wherein the insulation resistance can be greater than 20 MΩ and the leakage current can be less than 2 mA to protect the safety of personnel and equipment.

[0038] The power processing unit 105 is used to stabilize the voltage input by the external power supply and provide stable power supply to the DC power calculation device 100 .

[0039] Exemplarily, the external power supply uses a 32V wide voltage, and the power processing unit 105 is used to step down the input wide voltage to a stable 5V to power the DC computing device, ensuring safe and stable power use.

[0040] The present invention provides a direct current electricity quantity calculation device, which includes: a voltage detection unit, a data processing unit, a high-voltage isolation unit and a power processing unit; wherein the output end of the voltage detection unit is electrically connected to the input end of the data processing unit, the output end of the data processing unit is electrically connected to the high-voltage side input end of the high-voltage isolation unit, the output end of the power processing unit is electrically connected to the low-voltage side input end of the high-voltage isolation unit, and the voltage detection unit, the data processing unit, the high-voltage isolation unit and the power processing unit are integrated into one to form the direct current electricity quantity calculation device, and the direct current electricity quantity calculation device is connected in series with a high-voltage battery pack. A DC power calculation device is formed by integrating a voltage detection unit, a data processing unit, a high-voltage isolation unit and a power processing unit, and electrically connected to a high-voltage battery pack. The weak voltage signal generated by the voltage detection unit is processed into a target digital signal by the data processing unit, and current integration is used to complete the target power calculation of the high-voltage battery pack, and then the target power is sent to the main control unit of the battery pack management system of the high-voltage battery pack, thereby realizing high-speed and high-precision current collection and power calculation functions, so that the main control unit of the battery pack management system can timely grasp the power status of the high-voltage battery pack; and the high-voltage isolation unit isolates the high-voltage side from the low-voltage safety side, and its withstand voltage value can reach AC5000Vrms, further ensuring the safety of the DC power calculation device and personnel, and realizing a low-cost, highly stable and easy-to-use DC power calculation device.

[0041] See also Figure 2 , Figure 2 A DC power calculation method according to an embodiment of the present invention is provided. Figure 2 The method shown is applied to Figure 1 The DC power calculation device shown, the method includes:

[0042] 201. Acquire a weak voltage signal detected by a voltage detection unit;

[0043] The weak voltage signal is a weak voltage signal corresponding to the current at both ends of the high-voltage battery pack 101 .

[0044] It is understandable that the voltage detection unit 102 is connected in series with the high-voltage battery pack 101. Changes in the current in the high-voltage battery pack 101 will cause the current inside the voltage detection unit 102 to change at the same time. According to Ohm's law, the current can be converted into a weak voltage signal.

[0045] 202. Perform signal conversion on the weak voltage signal to obtain a target digital signal, where the target digital signal is a digital signal corresponding to the weak voltage signal;

[0046] It should be noted that signal conversion includes but is not limited to signal acquisition, signal filtering, analog-to-digital conversion, and power calculation.

[0047] 203. Obtain a target power of the high-voltage battery pack according to the target digital signal and a preset power algorithm;

[0048] In one feasible implementation, the preset power algorithm can use Ohm's law to solve the target current corresponding to the target digital signal, and then perform current integral calculation on the target current and the time corresponding to the current, so as to solve the target power of the high-voltage battery pack.

[0049] 204. Transmit the target power to a main control unit of a battery pack management system of the high-voltage battery pack.

[0050] In a feasible implementation, the integrated target power is transmitted to the main control unit of the battery pack management system of the high-voltage battery pack to indicate the working status of the high-voltage battery pack, so that the main control unit can manage the high-voltage battery pack according to the indication.

[0051] The present invention provides a direct current power calculation method, which is applied to a direct current power calculation device, and the method includes: obtaining a weak voltage signal detected by a voltage detection unit; performing signal conversion on the weak voltage signal to obtain a target digital signal, wherein the target digital signal is a digital signal corresponding to the weak voltage signal; obtaining a target power of a high-voltage battery pack according to the target digital signal and a preset power algorithm; and transmitting the target power to a main control unit of a battery pack management system of the high-voltage battery pack. By processing the weak voltage signal generated by the voltage detection unit into a target digital signal, and using a preset power algorithm to complete the target power calculation of the high-voltage battery pack, and then sending the target power to the main control unit of the battery pack management system of the high-voltage battery pack, high-speed and high-precision current acquisition and power calculation functions are realized, so that the main control unit of the battery pack management system can timely grasp the power status of the high-voltage battery pack.

[0052] Exemplarily, a DC power calculation device in an embodiment of the present invention is described by taking a high-voltage battery pack suitable for use in a shield machine excavation system as an example. The shield machine excavation system is often used for tunnel excavation, such as underground transportation, underground shopping malls and other underground construction. The shield machine excavation system also includes a tunnel horizontal transport electric locomotive, which is used to transport construction materials such as pipe segments and mortar from the wellhead to the inside of the tunnel. The battery system provides power to the tunnel horizontal transport electric locomotive to drive the tunnel horizontal transport electric locomotive to move.

[0053] Please continue reading Figure 3 , Figure 3 FIG. 1 is another schematic diagram of an application environment of a DC power calculation device according to an embodiment of the present invention. Figure 3 The DC power calculation device 300 shown includes: a voltage detection unit 302, a data processing unit 303, a high-voltage isolation unit 304, a power processing unit 305 and a communication unit 306; wherein the output end of the voltage detection unit 302 is electrically connected to the input end of the data processing unit 303, the output end of the data processing unit 303 is electrically connected to the high-voltage side input end of the high-voltage isolation unit 304, the output end of the power processing unit 305 is electrically connected to the low-voltage side input end of the high-voltage isolation unit 304, the communication unit 306 is connected to the low-voltage side of the high-voltage isolation unit 304, and the voltage detection unit 302, the data processing unit 303, the high-voltage isolation unit 304, the power processing unit 305 and the communication unit 306 are integrated into one to form the DC power calculation device 300, and the DC power calculation device 300 is connected in series with the high-voltage battery pack 301.

[0054] Understandably, Figure 3 The high-voltage battery pack 301 and the voltage detection unit 302, the data processing unit 303, the high-voltage isolation unit 304, and the power processing unit 305 in the DC power calculation device 300 are partially similar to the Figure 1 The descriptions of the high-voltage battery pack 101 and the voltage detection unit 102, the data processing unit 103, the high-voltage isolation unit 104 and the power processing unit 105 in the DC power calculation device 100 are similar and will not be repeated here to avoid repetition.

[0055] In a feasible implementation, the data processing unit 303 includes: a microcontroller module and a differential filter circuit; the input end of the differential filter circuit is electrically connected to the output end of the voltage detection unit 302, and the output end of the differential filter circuit is electrically connected to the input end of the microcontroller module;

[0056] The differential filter circuit is used to filter the weak voltage signal to obtain a filtered voltage signal;

[0057] In one feasible implementation, a differential filter circuit is used to perform signal conversion processing on a weak voltage signal, wherein the differential filter circuit can be an RC low-pass filter circuit, and the RC low-pass filter circuit is used to filter the weak voltage signal detected by the voltage detection unit 302 to obtain a filtered voltage signal, and the filtered voltage signal is transmitted to the micro-control module to continue signal conversion.

[0058] The microcontrol module is used to collect the filtered voltage signal using a preset collection mechanism to obtain the target digital signal and the target electrical quantity corresponding to the target digital signal.

[0059] It should be noted that the microcontroller module further performs signal conversion on the obtained filtered voltage signal, obtains the target power through signal acquisition, analog-to-digital conversion and power calculation, and transmits the target power to the main control unit of the battery pack management system.

[0060] In a feasible implementation, the microcontrol module includes a microcontroller chip, a fully differential analog-to-digital conversion circuit, and a preset number of thermistors; the input end of the fully differential analog-to-digital conversion circuit is electrically connected to the output end of the differential filter circuit, the output end of the fully differential analog-to-digital conversion circuit is electrically connected to the microcontroller chip, and the thermistor is electrically connected to the microcontroller chip;

[0061] The thermistor is used to detect the ambient temperature and transmit the ambient temperature to the microcontroller chip.

[0062] It should be noted that the ambient temperature detected by the thermistor is used to instruct the microcontroller chip to obtain the resistance value of the voltage detection unit 302 for calculating the target power.

[0063] Exemplarily, the thermistor may be an NTC (Negative Temperature Coefficient), which refers to a thermistor phenomenon and material having a negative temperature coefficient and whose resistance decreases exponentially with increasing temperature. The number of NTCs includes but is not limited to 4, and all are electrically connected to the microcontroller chip.

[0064] The fully differential analog-to-digital conversion circuit is used to collect the filtered voltage signal using a preset collection mechanism to obtain the target digital signal, and transmit the target digital signal to the microcontroller chip.

[0065] The fully differential analog-to-digital conversion circuit collects the target voltage signal, ie, the filtered voltage signal, inputted through the differential filtering circuit and converts it into a target digital signal.

[0066] The preset collection mechanism includes the collection frequency, the number of collections in each collection cycle and the number of cycle cycles. The collection frequency can be T, the number of collections in each collection cycle is N, and the number of cycle cycles is M.

[0067] Exemplarily, the acquisition frequency T may be 1 ms / time, the number of acquisitions N in each acquisition cycle is 10, and the number of cycles of the cycle is 10.

[0068] Moreover, each time an acquisition cycle is executed, 10 filtered voltage signals are trapezoidally filtered to obtain 10 filtered digital signals, and each filtered digital signal is cached; when the acquisition cycle reaches the cycle number 10, the 10*10 filtered digital signals are secondary filtered to smooth the data and obtain the target digital signal.

[0069] The microcontroller chip is used to receive the ambient temperature and the target digital signal, and obtain the target power according to the ambient temperature, the target digital signal and a preset power algorithm, and transmit the target power to the main control unit of the battery pack management system of the high-voltage battery pack 301.

[0070] In a feasible implementation, the preset electric quantity algorithm includes but is not limited to Ohm's law, a linear fitting function of temperature and resistance, and current integration.

[0071] In the embodiment of the present invention, the high-voltage isolation unit 304 is selected as an isolated DC-DC converter of model Adum6201 and integrated with model IsoPower. When the power processing unit 305 inputs a 5.0V power supply, it can provide 400mW of regulated isolation power to power the data processing circuit. Adum6201 also integrates two digital isolators to provide a channel for digital signal transmission. The isolation voltage of Adum6201 is 5000Vrms, which meets the reinforced insulation requirements under the voltage level of electric locomotives (according to standard GB / T18384.3-2015 7.3.3.3.2).

[0072] In an embodiment of the present invention, the power processing unit 305 includes: an anti-reverse connection circuit, a transient suppression circuit, a filter circuit, an ultra-low electromagnetic interference circuit and a switching regulator; the wide voltage input by the external power supply is input to the switching regulator via the anti-reverse connection circuit, the transient suppression circuit, the filter circuit, and the ultra-low electromagnetic interference circuit; the switching regulator is used to step down the wide voltage input by the external power supply and supply power to the DC power calculation device 300.

[0073] Exemplarily, the switching regulator selected is LT8619, which is a compact, high-efficiency, high-speed, synchronous, monolithic, step-down switching regulator with an output ripple less than 10mVp-p, and can well power other circuits.

[0074] The communication unit 306 includes but is not limited to a Controller Area Network (CAN) data bus, which uses a data communication protocol to provide a data transmission channel between the DC computing device and the corresponding terminal for establishing communication.

[0075] In a feasible implementation, the communication unit 306 includes a CAN transceiver with a filter circuit and a transient suppression circuit, and the target power is transmitted to the CAN bus through the filter circuit and the transient suppression circuit. The CAN transceiver model can be NXP's TJA1042, which is a high-speed CAN transceiver that complies with the ISO11898 standard and can provide differential transmission drive capability and differential drive acceptance capability for bus signals; the filter circuit uses a TDK dedicated common mode filter, and the transient suppression circuit uses a Littelfuse dedicated TVS, which has small parasitic capacitance, fast response, and large power peak, so that data transmission is stable and undistorted.

[0076] In the embodiment of the present invention, the DC power calculation device 300 further includes: a host computer management unit.

[0077] The upper computer management unit is used to debug, calibrate and analyze the performance parameters of the high-voltage battery pack 301, as well as debug, calibrate and analyze the performance parameters of the DC computing equipment.

[0078] The present invention provides a direct current electricity quantity calculation device, which comprises: a voltage detection unit, a data processing unit, a high-voltage isolation unit, a power processing unit and a communication unit; wherein the output end of the voltage detection unit is electrically connected to the input end of the data processing unit, the output end of the data processing unit is electrically connected to the high-voltage side input end of the high-voltage isolation unit, the output end of the power processing unit is electrically connected to the low-voltage side input end of the high-voltage isolation unit, the communication unit is connected to the low-voltage side of the high-voltage isolation unit, and the voltage detection unit, the data processing unit, the high-voltage isolation unit, the power processing unit and the communication unit are integrated into one to form the device, and the direct current electricity quantity calculation device is connected in series with a high-voltage battery pack. A DC power calculation device is formed by integrating a voltage detection unit, a data processing unit, a high-voltage isolation unit, a power processing unit and a communication unit, and electrically connected to a high-voltage battery pack. The weak voltage signal generated by the voltage detection unit is processed into a target digital signal by the data processing unit, and the target power calculation of the high-voltage battery pack is completed by current integration, and then the target power is sent to the main control unit of the battery pack management system of the high-voltage battery pack, thereby realizing high-speed and high-precision current acquisition and power calculation functions, so that the main control unit of the battery pack management system can timely grasp the power status of the high-voltage battery pack; and the high-voltage isolation unit isolates the high-voltage side from the low-voltage safety side, and its withstand voltage value can reach AC5000Vrms, further ensuring the safety of equipment and personnel, and realizing a low-cost, highly stable and easy-to-use DC power calculation device, and the communication unit and the host computer management unit can also exchange data to realize the debugging, calibration and analysis of the performance parameters of the high-voltage battery pack.

[0079] Please continue reading Figure 4 , Figure 4 FIG. 1 is another flow chart of a method for calculating direct current electricity in an embodiment of the present invention. Figure 4 The methods shown include:

[0080] 401. Acquire a weak voltage signal detected by the voltage detection unit 302;

[0081] 402. Filter the weak voltage signal using a differential filter circuit to obtain a filtered voltage signal;

[0082] 403. Using a fully differential analog-to-digital conversion circuit, the filtered voltage signal is sampled for a preset number of cycles M at a preset sampling frequency T and a preset number of sampling times N, to obtain M groups of sampled signals, wherein the M groups of sampled signals include N filtered voltage signals;

[0083] 404. Perform trapezoidal filtering on each group of the collected signals to obtain N*M filtered digital signals;

[0084] 405. Perform secondary filtering on the N*M filtered digital signals to obtain a target digital signal;

[0085] Exemplarily, the acquisition frequency T can be 1ms / time, the number of acquisitions N in each acquisition cycle is 10, the number of cycles of the cycle is 10, and each acquisition cycle is performed with 10 filtered voltage signals trapezoidal filtering to obtain 10 filtered digital signals, and each filtered digital signal is cached; when the acquisition cycle reaches the number of cycle cycles of 10, the 10*10 filtered digital signals are secondary filtered, wherein the secondary filtering can be pipeline filtering to smooth the data and obtain the target digital signal.

[0086] 406. Obtain a target power of the high-voltage battery pack 301 according to the target digital signal and a preset power algorithm;

[0087] In the embodiment of the present invention, step 406 specifically includes:

[0088] i. Obtaining the resistance value of the voltage detection unit 302;

[0089] Wherein, before step i, the method further includes: obtaining the ambient temperature detected by the thermistor; and determining the resistance value of the voltage detection unit 302 using the ambient temperature and a linear fitting function of a preset temperature and resistance.

[0090] See also Figure 5 , Figure 5 Schematic diagram of a function curve of a linear fitting function of a preset temperature and resistance in an embodiment of the present invention, wherein the resistance of the shunt is 100 μΩ, and the linear fitting function of the preset temperature and resistance is as follows:

[0091] y=1×10- 6 x 3 +8×10- 6 x 2 +0.002x+0.9879

[0092] Where y represents the shunt resistance and x represents the ambient temperature detected by the thermistor.

[0093] ii. determining a target current using the target digital signal, the resistance value of the voltage detection unit 302 and Ohm's law;

[0094] iii. Integrate the target current and time to obtain the target power of the high-voltage battery pack 301.

[0095] It can be understood that the electric quantity Q=I x t, where I is the target current and t is the time.

[0096] Exemplarily, the integral calculation adopts trapezoidal integration with a period of 10 ms, and the target power is obtained by performing trapezoidal integration on the current and time.

[0097] 407 . Transmit the target power to a main control unit of a battery pack management system of the high-voltage battery pack 301 .

[0098] In a feasible implementation, the target power is transmitted to the main control terminal of the battery pack management system through the data communication protocol of the Controller Area Network (CAN).

[0099] The present invention provides a direct current power calculation method, which is applied to a direct current power calculation device, and the method includes: obtaining a weak voltage signal detected by a voltage detection unit; performing signal conversion on the weak voltage signal to obtain a target digital signal, wherein the target digital signal is a digital signal corresponding to the weak voltage signal; obtaining a target power of a high-voltage battery pack according to the target digital signal and a preset power algorithm; and transmitting the target power to a main control unit of a battery pack management system of the high-voltage battery pack. By processing the weak voltage signal generated by the voltage detection unit into a target digital signal, and using a preset power algorithm to complete the target power calculation of the high-voltage battery pack, and then sending the target power to the main control unit of the battery pack management system of the high-voltage battery pack, high-speed and high-precision current acquisition and power calculation functions are realized, so that the main control unit of the battery pack management system can timely grasp the power status of the high-voltage battery pack.

[0100] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the program can be stored in a non-volatile computer-readable storage medium. When the program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory may include random access memory (RAM) or external cache memory. As an illustration and not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).

[0101] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0102] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A DC power calculation device, characterized in that: The device comprises: a voltage detection unit, a data processing unit, a high-voltage isolation unit and a power processing unit; wherein the output end of the voltage detection unit is electrically connected to the input end of the data processing unit, the output end of the data processing unit is electrically connected to the high-voltage side input end of the high-voltage isolation unit, the output end of the power processing unit is electrically connected to the low-voltage side input end of the high-voltage isolation unit, and the voltage detection unit, the data processing unit, the high-voltage isolation unit and the power processing unit are integrated into one body to form the device, and the device is connected in series with the high-voltage battery pack; The high-voltage battery pack is used to store energy and is a calculation target of the DC power calculation device; The voltage detection unit is used to detect a weak voltage signal corresponding to the current at both ends of the high-voltage battery pack; The data processing unit is used to perform signal conversion on the weak voltage signal to obtain a target digital signal of the high-voltage battery pack and a target power corresponding to the target digital signal, and transmit the target power to a main control unit of a battery pack management system of the high-voltage battery pack, wherein the target digital signal is a digital signal corresponding to the weak voltage signal; The high-voltage isolation unit is used to isolate and protect the high-voltage side from the low-voltage side, the high-voltage side is one side of the high-voltage isolation unit where the high-voltage battery pack is located, and the low-voltage side is the other side relative to the high-voltage side; The power processing unit is used to stabilize the voltage input by the external power supply and provide stable power supply to the device; Wherein, the data processing unit includes: a microcontroller module and a differential filter circuit; the input end of the differential filter circuit is electrically connected to the output end of the voltage detection unit, and the output end of the differential filter circuit is electrically connected to the input end of the microcontroller module; The differential filter circuit is used to filter the weak voltage signal to obtain a filtered voltage signal; The microcontroller module is used to collect the filtered voltage signal using a preset collection mechanism to obtain the target digital signal and the target power corresponding to the target digital signal; Wherein, the microcontrol module further includes a microcontroller chip, a fully differential analog-to-digital conversion circuit and a preset number of thermistors; the input end of the fully differential analog-to-digital conversion circuit is electrically connected to the output end of the differential filter circuit, the output end of the fully differential analog-to-digital conversion circuit is electrically connected to the microcontroller chip, and the thermistor is electrically connected to the microcontroller chip; The thermistor is used to detect the ambient temperature and transmit the ambient temperature to the microcontroller chip; The fully differential digital-to-analog conversion circuit is used to collect the filtered voltage signal using a preset collection mechanism to obtain the target digital signal, and transmit the target digital signal to the microcontroller chip; The microcontroller chip is used to receive the ambient temperature and the target digital signal, obtain the target power according to the ambient temperature, the target digital signal and a preset power algorithm, and transmit the target power to the main control unit of the battery pack management system of the high-voltage battery pack; Wherein, the power processing unit includes: an anti-reverse connection circuit, a transient suppression circuit, a filter circuit, an ultra-low electromagnetic interference circuit and a switching regulator; The wide voltage input by the external power supply is input to the switching regulator via the anti-reverse connection circuit, the transient suppression circuit, the filter circuit, and the ultra-low electromagnetic interference circuit; The switching regulator is used to step down the wide voltage input by the external power supply and to supply power to the DC power calculation device.

2. The DC power calculation device according to claim 1, characterized in that: The device further comprises: a communication unit connected to the low voltage side of the high voltage isolation unit; The communication unit is used to provide a transmission channel for data exchange between the data processing unit and the main control unit of the battery pack management system of the high-voltage battery pack.

3. The DC power calculation device according to claim 1, characterized in that: The device also includes: a host computer management unit; The host computer management unit is used to debug, calibrate and analyze the performance parameters of the high-voltage battery pack.

4. A method for calculating direct current electricity, characterized in that: The method is applied to the DC power calculation device according to any one of claims 1 to 3, and the method comprises: Acquire a weak voltage signal detected by a voltage detection unit; Performing signal conversion on the weak voltage signal to obtain a target digital signal, wherein the target digital signal is a digital signal corresponding to the weak voltage signal; Obtaining a target power of the high-voltage battery pack according to the target digital signal and a preset power algorithm; The target power is transmitted to a main control unit of a battery pack management system of the high-voltage battery pack.

5. The method according to claim 4, characterized in that: The step of performing signal conversion on the weak voltage signal to obtain a target digital signal includes: Filtering the weak voltage signal using a differential filter circuit to obtain a filtered voltage signal; Using a fully differential analog-to-digital conversion circuit to perform signal acquisition of a preset cycle number M of the filtered voltage signal at a preset acquisition frequency T and an acquisition period with a preset acquisition number N, to obtain M groups of acquisition signals, wherein the M groups of acquisition signals include N filtered voltage signals; Performing trapezoidal filtering on each group of the collected signals to obtain N*M filtered digital signals; The N*M filtered digital signals are filtered twice to obtain a target digital signal.

6. The method according to claim 4, characterized in that: The step of obtaining the target power of the high-voltage battery pack according to the target digital signal and a preset power algorithm includes: Obtaining a resistance value of the voltage detection unit; Determining a target current using the target digital signal, the resistance value of the voltage detection unit and Ohm's law; The target current and time are integrated and calculated to obtain the target power of the high-voltage battery pack.

7. The method according to claim 6, characterized in that: The step of obtaining the resistance value of the voltage detection unit also includes: Obtaining the ambient temperature detected by the thermistor; The resistance value of the voltage detection unit is determined by using the ambient temperature, the preset temperature and the resistance linear fitting function.

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