Signal acquisition circuit and power electronic equipment

Abstract

The utility model discloses a signal acquisition circuit and power electronic equipment, and relates to the technical field of signal acquisition. According to the signal acquisition circuit, each conditioning branch in a signal conditioning circuit directly receives a corresponding path of signal in a signal to be acquired and conditions the corresponding path of signal to obtain a conditioned corresponding path of analog signal; a conversion branch in the analog-to-digital conversion circuit performs analog-to-digital conversion on the conditioned analog signal of the corresponding path to obtain a converted digital quantity of the corresponding path; and finally, the digital quantity of the corresponding path is isolated through each channel in the digital isolation circuit, so that acquisition and output are realized. Namely, safe isolation is achieved in a digital isolation mode, the influence of input resistance of an isolation operational amplifier in an analog isolation scheme is avoided, and the sampling precision of the system can be improved. In addition, a comparison circuit can be additionally arranged, a fault monitoring result can be directly uploaded in a digital signal mode, the influence of time delay caused by acquisition, conversion and data transmission of the analog-to-digital conversion circuit is avoided, and the real-time performance is better.

Description

Technical Field

[0001] The present application relates to the field of signal acquisition technology, and in particular to a signal acquisition circuit and a power electronic device. Background Art

[0002] In power electronic equipment, since signals such as voltage and current are directly involved in the system's control and abnormal protection processes, how to safely collect these signals and then identify whether the system currently has abnormal conditions such as overvoltage and overcurrent is crucial to the safe operation of the system.

[0003] Currently, to safely acquire signals such as voltage and current, especially high-voltage signals, devices such as isolation amplifiers are generally required. However, while isolation amplifiers achieve safe signal isolation between the high-voltage and low-voltage sides, they also have internal input resistance, which can affect sampling accuracy. Utility Model Content

[0004] In view of the above problems, this application provides a signal acquisition circuit and power electronic equipment to avoid the problem of low sampling accuracy caused by using an isolation operational amplifier for safety isolation. The specific solution is as follows:

[0005] The first aspect of the present application provides a signal acquisition circuit, comprising: a signal conditioning circuit, an analog-to-digital conversion circuit, and a digital isolation circuit; wherein,

[0006] The input end of the signal conditioning circuit serves as the input end of the signal acquisition circuit to receive the signal to be acquired;

[0007] The output end of the signal conditioning circuit is connected to the analog side of the analog-to-digital conversion circuit;

[0008] The digital side of the analog-to-digital conversion circuit is connected to the first side of the digital isolation circuit;

[0009] The second side of the digital isolation circuit serves as an acquisition output end of the signal acquisition circuit;

[0010] The signal conditioning circuit includes multiple conditioning branches, the analog-to-digital conversion circuit includes multiple conversion branches, and the digital isolation circuit is a multi-channel isolation circuit; each of the conditioning branches is connected to a corresponding channel in the digital isolation circuit through a corresponding conversion branch; the input end of each of the conditioning branches receives a corresponding channel signal in the signal to be collected.

[0011] In one possible implementation, the signal between the digital side of the analog-to-digital conversion circuit and the first side of the digital isolation circuit is: a serial or parallel communication signal;

[0012] The digital side of the conversion branch is connected to the corresponding communication interface of the first side of the digital isolation circuit;

[0013] The communication interfaces on the second side of the digital isolation circuit serve as interfaces corresponding to the acquisition output ends of the signal acquisition circuit.

[0014] In one possible implementation, the digital isolation circuit is a multi-channel isolation circuit;

[0015] The signal acquisition circuit further includes: at least one more signal conditioning circuit, and at least one more analog-to-digital conversion circuit;

[0016] The input end of each signal conditioning circuit receives the corresponding signal to be collected;

[0017] The output end of each of the signal conditioning circuits is connected to the analog side of the corresponding analog-to-digital conversion circuit;

[0018] The digital side of each analog-to-digital conversion circuit is connected to the corresponding path interface on the first side of the digital isolation circuit.

[0019] In a possible implementation, the signal acquisition circuit further includes: a plurality of comparison circuits;

[0020] An input terminal of the comparison circuit is connected to an output terminal of the corresponding conditioning branch;

[0021] Another input terminal of the comparison circuit receives a reference voltage;

[0022] The output end of the comparison circuit is connected to the corresponding digital interface on the first side of the digital isolation circuit;

[0023] The digital interfaces on the second side of the digital isolation circuit serve as interfaces corresponding to the comparison output terminals of the signal acquisition circuit.

[0024] In a possible implementation, the number of the comparison circuits is the same as the number of the conditioning branches.

[0025] In a possible implementation, the first side of the digital isolation circuit is a high-voltage side, and the second side of the digital isolation circuit is a low-voltage side.

[0026] In a possible implementation, the digital isolation circuit is a digital isolation chip.

[0027] In a possible implementation, the analog-to-digital conversion circuit is an analog-to-digital conversion sampling chip.

[0028] A second aspect of the present application provides a power electronic device, comprising: a main circuit, a processor, and at least one signal acquisition circuit as described in the first aspect or any implementation form of the first aspect; wherein,

[0029] The input end of the signal acquisition circuit receives the signal to be collected from the main circuit;

[0030] The output end of the signal acquisition circuit is connected to the processor;

[0031] The main circuit is controlled by the processor.

[0032] In a possible implementation, the number of the signal acquisition circuits is greater than one, or the number of the signal conditioning circuits in the signal acquisition circuits is greater than one.

[0033] By means of the above technical solution, the signal acquisition circuit provided by the present application first directly receives the corresponding signal in the signal to be collected by each conditioning branch in the signal conditioning circuit and conditions it to obtain the conditioned corresponding analog signal; then the conversion branch in the analog-to-digital conversion circuit performs analog-to-digital conversion on the conditioned corresponding analog signal to obtain the converted corresponding digital quantity; finally, the corresponding digital quantity is isolated by each channel in the digital isolation circuit to realize acquisition and output; that is, different from the analog isolation solution in the prior art, the present application realizes safe isolation in the form of digital isolation, avoids the influence of the input resistance of the isolation operational amplifier in the analog isolation solution, and can improve the sampling accuracy of the system; and, it can also realize simultaneous acquisition of multiple signals, with high acquisition efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The above and other features, advantages, and aspects of the various embodiments of the present disclosure will become more apparent with reference to the following detailed description in conjunction with the accompanying drawings. Throughout the drawings, the same or similar reference numerals represent the same or similar elements. It should be understood that the drawings are schematic and that the originals and elements are not necessarily drawn to scale.

[0035] Figure 1 A schematic diagram of the structure of the signal acquisition circuit provided in an embodiment of the present application;

[0036] Figure 2 Another structural diagram of the signal acquisition circuit provided in an embodiment of the present application;

[0037] Figure 3 A schematic diagram of a structure of a signal acquisition circuit provided in an embodiment of the present application when implementing a multi-channel acquisition solution;

[0038] Figure 4 A schematic diagram of the structure of a multi-channel acquisition solution provided by the prior art;

[0039] Figure 5 Another structural diagram of the signal acquisition circuit provided in the embodiment of the present application when implementing a multi-channel acquisition solution;

[0040] Figure 6 Another structural diagram of the signal acquisition circuit provided in an embodiment of the present application;

[0041] Figure 7 Another structural diagram of the signal acquisition circuit provided in the embodiment of the present application when implementing a multi-channel acquisition solution;

[0042] Figure 8 A schematic diagram of the structure of a power electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0043] The following describes the embodiments of the present application in conjunction with the accompanying drawings. The terms used in the implementation methods of the present application are only used to explain the specific embodiments of the present application and are not intended to limit the present application.

[0044] The embodiments of the present application are described below in conjunction with the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application. It is known to those of ordinary skill in the art that with the development of technology and the emergence of new scenarios, the technical solutions provided in the embodiments of this application are also applicable to similar technical problems.

[0045] The terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequential order. It should be understood that the terms used in this way can be interchangeable under appropriate circumstances, and this is merely a way of distinguishing the objects of the same attributes when describing them in the embodiments of the present application. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, so that the process, method, system, product or equipment comprising a series of units need not be limited to those units, but may include other units that are not clearly listed or inherent to these processes, methods, products or equipment.

[0046] The present invention provides a signal acquisition circuit to avoid the problem of low sampling accuracy caused by using an isolation operational amplifier for safety isolation. The specific solution is as follows:

[0047] See also Figure 1 The signal acquisition circuit 10 includes: a signal conditioning circuit 101, an analog-to-digital conversion circuit 102 and a digital isolation circuit 103; wherein:

[0048] The input end of the signal conditioning circuit 101 serves as the input end of the signal acquisition circuit 10 to receive the signal to be collected. The signal to be collected can be any voltage or current signal that needs to be collected in any power electronic device. This is not limited here and depends on the specific application environment.

[0049] The output end of the signal conditioning circuit 101 is connected to the analog side of the analog-to-digital conversion circuit 102; the digital side of the analog-to-digital conversion circuit 102 is connected to the first side of the digital isolation circuit 103; the second side of the digital isolation circuit 103 serves as the acquisition output end of the signal acquisition circuit 10.

[0050] In practical applications, such as Figure 2 As shown in , the acquisition output end of the signal acquisition circuit 10 can be connected to the processor 20 in the corresponding power electronic device. Since the signal to be collected in the power electronic device is usually a high-voltage signal, and the signal input and output of the processor 20 is generally a low-voltage signal, the first side of the digital isolation circuit 103 can be a high-voltage side, and the second side of the digital isolation circuit 103 can be a low-voltage side. At this time, the digital isolation circuit 103 can achieve voltage reduction and isolation at the same time.

[0051] In practical applications, the signal to be collected may include multiple signals. For example, the power electronic device may have multiple voltage or current signals that need to be collected, or the power electronic device may have at least one voltage signal and at least one current signal that need to be collected. Therefore, Figure 3 As shown in , it can be set up that: the signal conditioning circuit 101 includes multiple conditioning branches 111, the analog-to-digital conversion circuit 102 includes multiple conversion branches 121, and the digital isolation circuit 103 is a multi-channel isolation circuit; wherein, each conditioning branch 111 is connected to the corresponding channel in the digital isolation circuit 103 through a corresponding conversion branch 121, and the input end of each conditioning branch 111 respectively receives the corresponding path signal in the signal to be collected, that is, the output end of each conditioning branch 111 is respectively connected to the analog side of the corresponding conversion branch 121, and the digital side of each conversion branch 121 is respectively connected to the corresponding path interface of the first side of the digital isolation circuit 103.

[0052] The specific working principle is:

[0053] The conditioning branch 111 conditions the corresponding signal in the signal to be collected to obtain a conditioned analog signal. For example, the conditioning branch 111 can adjust the amplitude of the corresponding signal in the signal to be collected from a current higher voltage value to a range of -5V to +5V or -10 to +10V. The conditioning branch 111 then transmits the conditioned analog signal to the corresponding conversion branch 121 in the subsequent analog-to-digital conversion circuit 102.

[0054] The conversion branch 121 performs analog-to-digital conversion on the conditioned analog signal, converting it into a digital quantity and outputting it to the corresponding interface on the first side of the digital isolation circuit 103. The digital isolation circuit 103 isolates the digital quantity it receives and outputs it to the processor 20 through its second side. In this case, the digital isolation circuit 103 is a multi-channel isolation circuit, with at least one interface on its first side and at least one interface on its second side. The corresponding interfaces on both sides are isolated through corresponding channels; that is, the digital quantity received by any interface on the first side will be isolated through the corresponding channel and output to the processor 20 through the corresponding interface on the second side.

[0055] Assuming that there are 4 voltage signals that need to be collected in the power electronic device, the signals to be collected include these 4 voltage signals. Each conditioning branch 111 receives and conditions one voltage signal respectively, and then passes through the corresponding conversion branch 121 and the corresponding channel in the digital isolation circuit 103 in sequence, so that the processor 20 can obtain the corresponding isolated digital quantity.

[0056] The number of signal paths included in the signal to be collected can be other values ​​and is not limited here; in addition, the various signals in the signal to be collected can be voltage signals, current signals, or signals of different types; it depends on the specific application environment and is within the protection scope of this application.

[0057] When the first side of the digital isolation circuit 103 is a high-voltage side and the second side is a low-voltage side, safety isolation between the high-voltage side and the low-voltage side can be achieved.

[0058] After receiving the isolated digital quantity, the processor 20 can control the operation of the power electronic device based on the isolated digital quantity. In one example, the processor 20 can compare the isolated digital quantity with a preset threshold value through its own software fault monitoring function; if the isolated digital quantity is greater than the threshold value, it can be determined that the corresponding power electronic device has a fault; for example, when the signal to be collected is a voltage signal, it can be determined that the power electronic device has an overvoltage fault; when the signal to be collected is a current signal, it can be determined that the power electronic device has an overcurrent fault; and then, the processor 20 can issue corresponding instructions to perform fault protection on the power electronic device.

[0059] In the signal acquisition circuit 10 provided in this embodiment, each conditioning branch 111 in the signal conditioning circuit 101 first directly receives the corresponding signal in the signal to be collected and conditions it to obtain the conditioned analog signal of the corresponding path; then the conversion branch 121 in the analog-to-digital conversion circuit 102 performs analog-to-digital conversion on the conditioned analog signal of the corresponding path to obtain the converted digital quantity of the corresponding path; finally, the digital quantity of the corresponding path is isolated by each channel in the digital isolation circuit 103 to realize acquisition and output; that is, different from the analog isolation scheme in the prior art, this embodiment realizes safe isolation in the form of digital isolation, avoids the influence of the input resistance of the isolation operational amplifier in the analog isolation scheme, can improve the sampling accuracy of the system, and makes the circuit design more flexible.

[0060] Furthermore, the signal acquisition circuit 10 provided in this embodiment can realize multi-channel acquisition. Figure 4 When existing technologies use isolation operational amplifiers to achieve multi-channel acquisition, they need to use multiple isolation operational amplifiers to perform analog isolation on the corresponding signals to be acquired, and transmit the isolated analog signals to the signal conditioning circuits to which they are connected. After being conditioned by the corresponding signal conditioning circuits, the analog signals can be transmitted to the AD sampling module of the processor. This solution requires the use of multiple isolation operational amplifiers, which is very expensive given the high unit price of isolation operational amplifiers. However, in this embodiment, multi-channel acquisition can be achieved through a multi-channel isolation circuit, which can significantly reduce the cost of multi-channel acquisition and has obvious advantages. Moreover, this embodiment can achieve simultaneous acquisition of multiple signals, with high acquisition efficiency.

[0061] Furthermore, the digital isolation solution provided by this embodiment not only has a simple design structure but also easily addresses safety issues associated with medium- and high-voltage sampling, thereby increasing the system voltage level of power electronic equipment applications. Furthermore, compared to the high cost of isolation operational amplifiers in the prior art, the digital isolation circuit 103 used in this embodiment is low-cost. Therefore, the digital isolation solution offers a cost advantage over analog isolation solutions.

[0062] In practical applications, the digital isolation circuit 103 can be implemented using an integrated chip, that is, the digital isolation circuit 103 can be a digital isolation chip. There are many types of chips available, and their cost is relatively low. The specific choice of chip is not limited here. Any chip that can achieve the corresponding isolation function is within the scope of protection of this application. Furthermore, the digital isolation circuit 103 can also be implemented using discrete components, depending on the specific application environment, and is also within the scope of protection of this application.

[0063] Similarly, the analog-to-digital conversion circuit 102 can be constructed using discrete devices or implemented using an integrated chip, that is, the analog-to-digital conversion circuit 102 can be an analog-to-digital conversion sampling chip, such as Figure 2 The AD (Analog-Digital) sampling chip shown in the figure is not limited to its specific implementation form, and any chip that can realize the above-mentioned analog-to-digital conversion and sampling functions is within the scope of protection of this application.

[0064] Based on the previous embodiment, this embodiment provides another example of the signal acquisition circuit 10 implementing multi-channel acquisition, such as Figure 5 As shown in , it can also be set that the signal acquisition circuit 10 further includes: at least one other signal conditioning circuit 101, and at least one other analog-to-digital conversion circuit 102. Specifically:

[0065] The input end of each signal conditioning circuit 101 receives a corresponding signal to be collected; that is, the input end of each signal conditioning circuit 101 can respectively receive a corresponding signal to be collected; in addition, each signal to be collected can include multiple signals, and the number of each signal to be collected can be the same or different, depending on the specific application environment, and all are within the protection scope of this application.

[0066] The output end of each signal conditioning circuit 101 is connected to the analog side of the corresponding analog-to-digital conversion circuit 102 ; the digital side of each analog-to-digital conversion circuit 102 is connected to the corresponding path interface of the first side of the digital isolation circuit 103 .

[0067] At this time, the digital isolation circuit 103 is a multi-channel isolation circuit, with at least one interface on its first side and at least one interface on its second side, and the corresponding interfaces on both sides are isolated through corresponding channels; that is, the digital quantity received by any interface on its first side will be isolated through the corresponding channel and then output to the processor 20 by the corresponding interface on its second side.

[0068] Assume that there are 8 voltage signals to be collected in the power electronic equipment. At this time, they can be divided into two to-be-collected signals, each of which includes 4 voltage signals. At this time, Figure 5 The signal conditioning circuit 101 and the analog-to-digital conversion circuit 102 in the Figure 3 In practical applications, the total number of conversion branches 121 in each analog-to-digital conversion circuit 102 may be equal to or less than the number of channels in the digital isolation circuit 103; this may depend on the specific application environment and is within the scope of protection of this application.

[0069] Similarly, the number of signal paths included in the signal to be collected can be other values, which is not limited here; in addition, the various signals in the signal to be collected can be voltage signals, current signals, or signals of different types; it depends on the specific application environment and is within the scope of protection of this application.

[0070] In actual applications, in the signal acquisition circuit 10, the signal between the digital side of the analog-to-digital conversion circuit 102 and the first side of the digital isolation circuit 103 is: a serial or parallel communication signal; that is, the digital side of the conversion branch 121 in the analog-to-digital conversion circuit 102 is connected to the corresponding communication interface on the first side of the digital isolation circuit 103; each communication interface on the second side of the digital isolation circuit 103 serves as the corresponding interface of the acquisition output end of the signal acquisition circuit 10.

[0071] for Figure 2 In the structure shown, the analog-to-digital conversion circuit 102 performs analog-to-digital conversion on each analog signal conditioned by the signal conditioning circuit 101 to obtain each converted digital quantity; and the analog-to-digital conversion circuit 102 also transmits each converted digital quantity through its own digital side to the digital isolation circuit 103 in a serial or parallel communication manner; and then the digital isolation circuit 103 isolates each digital quantity and outputs it to the processor 20.

[0072] for Figure 5 In the structure shown, each analog-to-digital conversion circuit 102 performs analog-to-digital conversion on each analog signal conditioned by the connected signal conditioning circuit 101 to obtain each corresponding converted digital quantity; and each analog-to-digital conversion circuit 102 also transmits each corresponding converted digital quantity to the digital isolation circuit 103 through its own digital side in a serial or parallel communication manner; and then the digital isolation circuit 103 isolates each digital quantity output by each analog-to-digital conversion circuit 102 and outputs it to the processor 20.

[0073] To address the impact of the input resistance of the isolation operational amplifier (OPA) on circuit sampling accuracy in the prior art, this embodiment eliminates the isolation operational amplifier, ensuring analog signal accuracy. Analog-to-digital conversion circuit 102 is used to convert the analog signal into a digital quantity before uploading it via communication. Furthermore, digital isolation circuit 103 can be used to digitally isolate the communication signal. This entire process does not affect signal accuracy and achieves safety isolation between the high-voltage and low-voltage side signals.

[0074] On the basis of the above embodiment, this embodiment provides another signal acquisition circuit 10, see Figure 6 (In Figure 3 The structure shown is shown as an example) or Figure 7 (In Figure 5 (The structure shown is used as an example for demonstration) In addition to the circuits described in the above embodiments, the signal acquisition circuit 10 further includes: multiple comparison circuits 104; wherein: one input end of the comparison circuit 104 is connected to the output end of the corresponding conditioning branch 111, and receives the conditioned analog signal output by the corresponding conditioning branch 111; the other input end of the comparison circuit 104 receives the reference voltage; the output end of the comparison circuit 104 is connected to the corresponding digital interface on the first side of the digital isolation circuit 103; and the digital interfaces on the second side of the digital isolation circuit 103 serve as the corresponding interfaces of the comparison output end of the signal acquisition circuit 10.

[0075] for Figure 6 In the structure shown, each signal in the signal to be collected passes through the corresponding conditioning branch 111 to obtain a conditioned analog signal; the conditioned analog signal is not only transmitted to the processor 20 via the digital isolation circuit 103 in a communication manner after conversion by the conversion branch 121, but also compared with the reference voltage by the comparison circuit 104, and the comparison result is output in the form of a digital signal; the digital signal is used to indicate whether an overcurrent or overvoltage fault occurs at the position of the corresponding signal in the signal to be collected in the power electronic device; the comparison circuit 104 outputs the digital signal to the corresponding digital interface on the first side of the digital isolation circuit 103; the corresponding digital interface on the second side of the digital isolation circuit 103, as the corresponding interface at the comparison output end of the signal acquisition circuit 10, outputs the isolated digital signal to the processor 20, so that the processor 20 can obtain the fault monitoring result of whether an overcurrent or overvoltage fault occurs at the corresponding position.

[0076] for Figure 7 In the structure shown in FIG. 1 , the number of the comparison circuits 104 is the same as the number of the conditioning branches 111; that is, each signal to be collected corresponds to a group of signal conditioning circuits 101, analog-to-digital conversion circuits 102 and multiple ( Figure 7 Only one of them is exemplarily shown in the figure) the comparison circuit 104, and then the processor 20 can obtain the corresponding isolated digital quantity and digital signal through the corresponding above processes.

[0077] In this embodiment, the comparison circuit 104 directly uploads the fault monitoring results in the form of digital signals, and is not affected by the delay caused by the acquisition, conversion and data transmission of the analog-to-digital conversion circuit 102. Therefore, compared with the software fault monitoring method described in the above embodiment, the hardware comparison method used in this embodiment to achieve better real-time performance of the fault monitoring function.

[0078] In actual applications, the fault monitoring function can be implemented using either hardware or software, depending on the application environment. Of course, the presence of the comparison circuit 104 does not affect the retention of the software fault monitoring function in the processor 20. That is, both hardware and software fault monitoring functions can exist simultaneously to improve the reliability of the fault monitoring results. This depends on the specific application environment and is within the scope of protection of this application.

[0079] Another embodiment of the present application further provides a power electronic device, such as Figure 8 As shown in FIG, the power electronic device includes: a main circuit 30, a processor 20 and at least one ( Figure 8 The signal acquisition circuit 10 is shown as an example in FIG; wherein the specific structure and working principle of the signal acquisition circuit 10 can be found in the above embodiment and will not be described in detail here. In addition:

[0080] The input end of the signal acquisition circuit 10 receives the signal to be collected from the main circuit 30; as described in the above embodiment, the signal to be collected may include a voltage or current signal at any position in the power electronic device, such as any voltage or current signal at the input side, output side or inside the main circuit 30, that is, the signal to be collected may specifically include a voltage collection signal or a current collection signal to be detected; this is not limited here, and it depends on the specific application environment, and all are within the protection scope of this application.

[0081] The output end of the signal acquisition circuit 10 is connected to the processor 20 to provide the above-mentioned isolated digital quantity, or provide the above-mentioned isolated digital quantity and digital signal simultaneously to the processor 20.

[0082] In actual applications, the processor 20 can have multiple options, such as DSP (Digital Signal Processor), ARM (Advanced RISC Machine, reduced instruction set computer microprocessor), FPGA (Field-Programmable Gate Array, field programmable gate array), CPU (Central Processing Unit, central processing unit), MCU (Microcontroller Unit, micro control unit), CPLD (Complex Programmable Logic Device, complex programmable logic device) and ASIC (Application Specific Integrated Circuits, application specific integrated circuit) chip. It depends on the specific application environment and is not specifically limited here. All of them are within the scope of protection of this application.

[0083] The main circuit 30 is controlled by the processor 20. The main circuit 30 has a variety of optional structures, such as a DC / DC conversion circuit, a DC / AC conversion circuit, an AC / DC conversion circuit, or an AC / AC conversion circuit, and can even be a transmission circuit with only controllable switches or fuses. The processor 20 controls the operation of the main circuit 30 by controlling the power switches, controllable switches, and other components in the circuit. Furthermore, this embodiment does not limit the type, number, or level of circuits used in the main circuit 30. For example, the main circuit 30 may include a DC / AC conversion circuit and at least one DC / DC conversion circuit connected to its DC side. The specific structural configuration of the main circuit 30 can be determined based on its actual application environment and is within the scope of protection of this application.

[0084] Depending on the structure of the main circuit 30, the power electronic device can be applied to different scenarios and realize different functions; for example, the power electronic device can be used as a medium- and high-voltage converter, transmission equipment, photovoltaic inverter, energy storage converter, etc. As long as it uses at least one signal acquisition circuit 10 as described in the above embodiment, it is within the scope of protection of this application and no further examples are given here.

[0085] In actual applications, there may be at least two signals to be collected in the main circuit 30. For example, when the main circuit 30 includes a DC / AC conversion circuit and multiple DC / DC conversion circuits, the input side voltage and input side current of each DC / DC conversion circuit, and the DC side voltage, AC side voltage, AC side current, etc. of the DC / AC conversion circuit can be used as corresponding signals to be collected respectively; and each signal to be collected can include multiple signals, for example, it can include the same signal of multiple DC / DC conversion circuits; for different structures of the main circuit 30 and the scenarios in which it is used, the signal to be collected can be determined according to the requirements of the actual application environment and is not limited here.

[0086] In the case where there are n signals to be collected in the main circuit 30, n is an integer greater than 1, and these signals can be regarded as n signals in a signal to be collected. Figure 3 or Figure 6 The signal acquisition circuit 10 shown in FIG. 1 is a circuit in which the digital isolation circuit 103 is an n-channel isolation circuit; alternatively, these signals can be used as individual signals in a plurality of signals to be collected, using Figure 5 or Figure 7 signal acquisition circuit 10; in practical applications, different types of signal acquisition circuits 10 can also be used at the same time, and the number of various signal acquisition circuits 10 is not limited, as long as the acquisition requirements of n-way signals can be met, they are all within the scope of protection of this application.

[0087] The power electronic device provided in this embodiment, by employing the signal acquisition circuit 10 described in the above embodiment, can address the impact of the input resistance of the isolation operational amplifier on circuit sampling accuracy in the prior art, while also achieving safety isolation between high-voltage and low-voltage signals, and increasing the system voltage level in the power electronic device's application scenarios. The design structure is simple and low-cost. Furthermore, in multi-channel acquisition applications, the multi-channel isolation circuit can further reduce costs and improve acquisition efficiency, offering significant advantages.

[0088] The same or similar parts between the various embodiments in this specification can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the system or system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment. The system and system embodiments described above are merely schematic, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment. Ordinary technicians in this field can understand and implement it without making any creative efforts.

[0089] Professionals may further appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the above description has generally described the components and steps of each example according to their functions. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians may use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0090] With respect to the above description of the disclosed embodiments, the features described in the various embodiments in this specification may be interchanged or combined to enable those skilled in the art to implement or use the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application is not limited to the embodiments shown herein, but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A signal acquisition circuit, characterized in that: include: Signal conditioning circuit, analog-to-digital conversion circuit and digital isolation circuit; among them, The input end of the signal conditioning circuit serves as the input end of the signal acquisition circuit to receive the signal to be acquired; The output end of the signal conditioning circuit is connected to the analog side of the analog-to-digital conversion circuit; The digital side of the analog-to-digital conversion circuit is connected to the first side of the digital isolation circuit; The second side of the digital isolation circuit serves as an acquisition output end of the signal acquisition circuit; The signal conditioning circuit includes a plurality of conditioning branches, the analog-to-digital conversion circuit includes a plurality of conversion branches, and the digital isolation circuit is a multi-channel isolation circuit; each of the conditioning branches is connected to a corresponding channel in the digital isolation circuit through a corresponding conversion branch; The input end of each conditioning branch receives a corresponding signal in the signal to be collected.

2. The signal acquisition circuit according to claim 1, characterized in that: The signal between the digital side of the analog-to-digital conversion circuit and the first side of the digital isolation circuit is: a serial or parallel communication signal; The digital side of the conversion branch is connected to the corresponding communication interface of the first side of the digital isolation circuit; The communication interfaces on the second side of the digital isolation circuit serve as interfaces corresponding to the acquisition output ends of the signal acquisition circuit.

3. The signal acquisition circuit according to claim 1, characterized in that: Also includes: at least one additional said signal conditioning circuit, and at least one additional said analog-to-digital conversion circuit; The input end of each signal conditioning circuit receives the corresponding signal to be collected; The output end of each of the signal conditioning circuits is connected to the analog side of the corresponding analog-to-digital conversion circuit; The digital side of each analog-to-digital conversion circuit is connected to the corresponding path interface on the first side of the digital isolation circuit.

4. The signal acquisition circuit according to any one of claims 1 to 3, characterized in that: Also includes: Multiple comparison circuits; An input terminal of the comparison circuit is connected to an output terminal of the corresponding conditioning branch; Another input terminal of the comparison circuit receives a reference voltage; The output end of the comparison circuit is connected to the corresponding digital interface on the first side of the digital isolation circuit; The digital interfaces on the second side of the digital isolation circuit serve as interfaces corresponding to the comparison output terminals of the signal acquisition circuit.

5. The signal acquisition circuit according to claim 4, characterized in that: The number of the comparison circuits is the same as the number of the conditioning branches.

6. The signal acquisition circuit according to any one of claims 1 to 3, characterized in that: The first side of the digital isolation circuit is a high-voltage side, and the second side of the digital isolation circuit is a low-voltage side.

7. The signal acquisition circuit according to any one of claims 1 to 3, characterized in that: The digital isolation circuit is a digital isolation chip.

8. The signal acquisition circuit according to any one of claims 1 to 3, characterized in that: The analog-to-digital conversion circuit is an analog-to-digital conversion sampling chip.

9. A power electronic device, characterized in that: include: A main circuit, a processor and at least one signal acquisition circuit according to any one of claims 1 to 8; wherein, The input end of the signal acquisition circuit receives the signal to be collected from the main circuit; The output end of the signal acquisition circuit is connected to the processor; The main circuit is controlled by the processor.

10. The power electronic device according to claim 9, characterized in that The number of the signal acquisition circuits is greater than 1, or the number of the signal conditioning circuits in the signal acquisition circuits is greater than 1.

Images