A detection system and method for power electronic converter control board

Abstract

The present invention discloses an automated detection system and method for a power electronic converter controller board. Through the designed detection system and method, it is possible to quickly detect whether each functional circuit (including a control chip, a sampling circuit, a drive circuit, an open-in and open-out circuit, and a communication circuit) inside the controller board is working properly, thereby improving the inspection efficiency of the controller board during large-scale production. The automated detection system includes the designed analog quantity test circuit, the switch quantity test circuit, and the human-computer interaction unit. The test circuit is easy to implement and the devices are all commonly used components. The test items and pass criteria can be set through the human-computer interaction unit, and the test results of each functional unit are automatically displayed. The entire detection system and method have the characteristics of low cost, automatic detection of each function, simple and fast operation, intuitive result display, full test coverage, and high test efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of power electronics, and in particular to a detection system and method applied to a control board of a power electronic converter. Background Art

[0002] In order to improve the safety and reliability of the power supply system, more and more power electronic grid-connected converter products are being applied to various industries (electricity, airports, hospitals, rail transit, etc.), including active power filters, static VAR compensators or three-phase unbalanced compensation devices, etc. The working principle of this type of product is basically the same, that is, the voltage and current values ​​detected in the power grid, system or load are sent to the controller card of the power electronic grid-connected converter. The controller card outputs the required voltage or current instructions through closed-loop control, and after the pulse width is modulated into PWM wave, it passes through the drive unit to control the action of the power device of the main circuit (IGBT / MOSFET and other switching tubes), and finally the high-voltage PWM pulse is output and high-frequency filtered to generate the voltage and current required by the power grid or load.

[0003] For power electronic grid-connected converter devices with smaller capacity, the mainstream in the market is modular products. Modular product design has the advantages of good scalability, easy maintenance, and low cost. Its controller system, power unit, drive unit, etc. are all located in the module, with high power density. In the mass production process, in order to ensure the quality and consistency of the product, the controller board and drive unit need to be tested after the PCBA welding production is completed.

[0004] The design principle of the controller board of the modular power electronic grid-connected converter is generally divided into control chips (DSP or FPGA, etc.), sampling and conditioning circuits, drive circuits, open-in and open-out circuits, communication circuits and other parts according to functions. Among them, the control chip is the core of the controller, which realizes the functions of command output, external control, communication and other functions required by the circuit; the sampling and conditioning circuit realizes the acquisition of grid and load voltage and current, and is used for closed-loop control and protection of the controller; the function of the drive circuit is to send the closed-loop pulse signal output by the control chip to the drive board, and finally control the action of the power device; the function of the open-in circuit is to receive external control signals; the function of the open-out circuit is to issue action instructions for external switches. The communication module realizes the data exchange function with the human-machine interface.

[0005] Therefore, the controller board of the power electronic grid-connected converter has the characteristics of complex functions and many circuit test points. The common AOI test can only detect the quality of welding and cannot determine whether the circuit function is normal. The common FCT test can use an external analog power supply to provide different analog quantities, input quantities, drive signals, etc. for different functional blocks in the circuit to test whether the corresponding output results are consistent with expectations. The general test process is complex, time-consuming and costly. Summary of the invention

[0006] The purpose of this section is to summarize some aspects of embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the specification abstract and the invention title of this application to avoid blurring the purpose of this section, the specification abstract and the invention title, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0007] In view of the above-mentioned detection problems in the existing control board card for power electronic converters, the present invention is proposed.

[0008] Therefore, the purpose of the present invention is to provide a detection system and method for a modular power electronic grid-connected converter controller board. The detection system has the advantages of simple circuit and complete functions, and the test method has the advantages of high test efficiency, full test coverage, and low test cost.

[0009] To solve the above technical problems, the present invention provides the following technical solutions: a detection system applied to a power electronic converter control board, comprising an analog quantity test circuit module, connected to the controller board, including a drive board, an analog quantity circuit input terminal and an analog quantity circuit output terminal; a switch quantity test circuit module, including a switch quantity circuit input terminal and a switch quantity circuit output terminal; and a human-computer interaction unit module, including a computer, a communication interface and a human-computer interaction unit interface.

[0010] As a preferred solution of the detection system applied to the power electronic converter control board of the present invention, the controller board includes a control chip, a drive circuit, a sampling circuit, a communication circuit, an output circuit and an input circuit.

[0011] As a preferred solution of the detection system applied to the power electronic converter control board of the present invention, the drive circuit is provided with a drive circuit output end and a drive circuit input end, and the sampling circuit is provided with a sampling circuit output end and a sampling circuit input end.

[0012] As a preferred solution of the detection system applied to the power electronic converter control board of the present invention, the output end of the drive circuit inside the controller board is connected to the input end of the analog circuit, and the output end of the analog circuit is connected to the input end of the sampling circuit inside the controller board.

[0013] As a preferred solution of the detection method applied to the power electronic converter control board card described in the present invention, wherein: the output of the output circuit of the controller board card is connected to the input end of the switch quantity test circuit of the automatic detection system, and the output end of the switch quantity test circuit is connected to the input end of the switch input circuit of the controller board card.

[0014] As a preferred solution of the detection method applied to the control board of the power electronic converter described in the present invention, the analog test circuit test step includes: after the control chip of the controller board under test receives the test start instruction of the human-computer interaction unit, the specified PWM pulse wave is input to the drive circuit; after the PWM pulse is amplified by the output of the drive circuit, it is converted into a corresponding DC signal through the RC capacitor filtering circuit and level conversion in the analog test circuit; the DC signal is then sent to the sampling circuit of the controller board under test after passing through the level isolation conversion circuit.

[0015] As a preferred scheme of the detection method applied to the control board of the power electronic converter described in the present invention, when the number of sampling circuits is greater than the input signal, one group of DC signals can correspond to multiple sampling and conditioning circuits, and the output signal of the sampling circuit of the controller board under test is sent to the control chip of the controller board under test for data processing such as A / D conversion.

[0016] As a preferred scheme of the detection method applied to the control board of the power electronic converter described in the present invention, wherein: the control chip compares the digital quantity after A / D conversion with the set value, and if the result is within the set deviation range, it is automatically determined that the drive unit, sampling unit and control chip of the controller board under test are normal; if it exceeds the set deviation range, it is automatically determined that the drive unit or sampling unit of the controller board under test is normal or the control chip is abnormal.

[0017] As a preferred scheme of the detection method applied to the control board of the power electronic converter described in the present invention, the switch quantity test circuit includes the following test steps: the output signal of the control chip output circuit of the controller board under test is connected to the switch quantity test circuit, and the output stage of the test circuit is connected to the input circuit part of the controller board; the control chip automatically determines that the input and output circuits are normal by comparing the levels of the output and input signals, otherwise it determines that the input or output circuits are abnormal.

[0018] As a preferred scheme of the detection method applied to the power electronic converter control board card described in the present invention, wherein: the controller board card is connected to the human-computer interaction unit through a communication circuit, and the test data and results are displayed on the human-computer interaction unit interface. If the human-computer interaction unit finds that the communication is abnormal, it determines and displays that the communication circuit of the controller board card under test is abnormal.

[0019] Beneficial effects of the present invention: Through the designed detection system and method, it is possible to quickly detect whether the various functional circuits (including control chips, sampling circuits, drive circuits, input and output circuits, and communication circuits) inside the controller board are working properly, thereby improving the inspection efficiency of the controller board during large-scale production. The automated detection system includes the designed analog quantity test circuit, switch quantity test circuit, and human-computer interaction unit. The test circuit is easy to implement and the devices are all commonly used components. The test items and pass criteria can be set through the human-computer interaction unit, and the test results of each functional unit can be automatically displayed. The entire detection system and method have the characteristics of low cost, automatic detection of various functions, simple and fast operation, intuitive result display, full test coverage, and high test efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. 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 creative labor. Among them:

[0021] Figure 1 The present invention is a test block diagram of a detection system applied to a power electronic converter control board.

[0022] Figure 2 The present invention is a circuit schematic diagram of an analog quantity test circuit for a detection method applied to a power electronic converter control board.

[0023] Figure 3 The present invention is a circuit schematic diagram of a switch quantity test circuit of a detection method applied to a power electronic converter control board.

[0024] Figure 4 The figure is a test effect diagram displayed on the human-machine interaction unit interface of the detection method of the present invention applied to the control board of the power electronic converter. DETAILED DESCRIPTION

[0025] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0026] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0027] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0028] Secondly, the present invention is described in detail with reference to the schematic diagram. When describing the embodiments of the present invention in detail, for the sake of convenience, the cross-sectional diagrams showing the device structure will not be partially enlarged according to the general scale, and the schematic diagrams are only examples, which should not limit the scope of protection of the present invention. In addition, in actual production, the three-dimensional dimensions of length, width and depth should be included.

[0029] Example 1

[0030] Reference Figures 1-2 A detection system for a power electronic converter control board includes an analog quantity test circuit module 100 connected to a controller board 400, including a driver board 101, an analog quantity circuit input terminal 102, and an analog quantity circuit output terminal 103; a switch quantity test circuit module 200, including a switch quantity circuit input terminal 201 and a switch quantity circuit output terminal 202; and a human-computer interaction unit module 300, including a computer 301, a communication interface 302, and a human-computer interaction unit interface 303. The controller board 400 includes a control chip 401, a drive circuit 402, a sampling circuit 403, a communication circuit 404, an output circuit 405, and an input circuit 406.

[0031] The driving circuit 402 is provided with a driving circuit output terminal 402a and a driving circuit input terminal 402b, and the sampling circuit 403 is provided with a sampling circuit output terminal 403a and a sampling circuit input terminal 403b. The driving circuit output terminal 402a inside the controller board 400 is connected to the analog circuit input terminal 102, and the analog circuit output terminal 103 is connected to the sampling circuit input terminal 403b inside the controller board 400. The output of the output circuit 405 of the controller board is connected to the input terminal 202 of the switch quantity test circuit 200 of the automatic detection system, and the output terminal 203 of the switch quantity test circuit 200 is connected to the input of the input circuit 406 of the controller board.

[0032] Specifically, Figure 1 As shown, the controller board 400 includes a control chip 401 (DSP, FPGA, etc.), a sampling circuit 403, a driving circuit 402, an input circuit 406, an output circuit 405, a communication circuit 404, etc. The test system of the controller board 400 under test mainly includes: an analog quantity test circuit 100, a switch quantity test circuit 200, and a human-computer interaction unit 300.

[0033] Furthermore, the controller board design principle of the modular power electronic grid-connected converter generally includes control chip 401 (DSP or FPGA, etc.), sampling and conditioning circuit 403, drive circuit 402, open-in and open-out circuit, communication circuit 404 and other parts according to the function. Among them, the control chip 401 is the core of the controller, realizing the functions of command output, external control, communication and other functions required by the circuit; the sampling and conditioning circuit 403 realizes the acquisition of grid and load voltage and current, and is used for closed-loop control and protection of the controller; the function of the drive circuit 402 is to send the closed-loop pulse signal output by the control chip to the drive board 101, and finally control the action of the power device; the function of the open-in circuit 406 is to receive external control signals; the function of the open-out circuit 405 is to issue action instructions for external switches. The communication module 302 realizes the data exchange function with the human-machine interface.

[0034] Furthermore, during the test, the control chip 401 of the controller board 400 sends a PWM drive pulse signal with a set pulse width. After passing through the drive circuit 402, the signal is sent to the analog test circuit 100. The output of the analog test circuit 100 is connected to the sampling circuit of the controller board, and finally sent to the control chip for sampling. When the control chip detects that the sampling value is consistent with the set value, it is determined that the drive unit is normal, the sampling unit is normal, and the control chip is normal. The output signal of the control chip 401 of the controller board is connected to the switch test circuit 100, and the output stage of the switch test circuit 100 is connected to the input circuit part of the controller board. The control chip 401 automatically determines that the input and output circuits are normal by comparing the level of the output and input signals. The controller is connected to the human-computer interaction unit through the communication circuit (CAN / 485 / 232), and the test data and results are displayed on the interactive interface. The test results are judged to be normal.

[0035] Example 2

[0036] Reference Figures 1 to 3, this embodiment is different from the first embodiment in that: this embodiment discloses a detection method applied to a control board of a power electronic converter, and the test steps of the analog quantity test circuit 500 include: after the control chip 401 of the tested controller board 400 receives the test start instruction of the human-machine interaction unit 300, it inputs a specified PWM pulse wave to the drive circuit 402; after the PWM pulse is output and amplified by the drive circuit 402, it is converted into a corresponding DC signal through the RC capacitor filter circuit and level conversion in the analog quantity test circuit 100; the DC signal is then sent to the sampling circuit 403 of the tested controller board 400 after passing through the level isolation conversion circuit. When the number of sampling circuits is greater than the input signal, one group of DC signals can correspond to multiple sampling and conditioning circuits, and the output signal of the sampling circuit 403 of the tested controller board is sent to the control chip 401 of the tested controller board for data processing such as A / D conversion. The control chip 401 compares the digital quantity after A / D conversion with the set value. If the result is within the set deviation range, it is automatically determined that the drive unit, sampling unit and control chip of the controller board 401 under test are normal; if it exceeds the set deviation range, it is automatically determined that the drive unit or sampling unit of the controller board 401 under test is normal or the control chip is abnormal.

[0037] The switch quantity test circuit 600 includes the following test steps: the control chip 401 of the tested controller board 400 has the output circuit output signal connected to the switch quantity test circuit 200, and the output stage of the test circuit is connected to the input circuit part of the controller board 400; the control chip automatically determines that the input and output circuits are normal by comparing the levels of the output and input signals, otherwise it determines that the input or output circuits are abnormal. The controller board 400 is connected to the human-computer interaction unit 700 through the communication circuit, and the test data and results are displayed on the human-computer interaction unit interface. If the human-computer interaction unit 700 finds that the communication is abnormal, it determines and displays that the communication circuit of the tested controller board 400 is abnormal.

[0038] Specifically, Figure 2 The figure shows the internal circuit of the analog quantity test circuit 500. The circuit principle is as follows: the Vin input terminal is a pulse signal output by the controller driving circuit. The pulse signal has a fixed duty cycle. After passing through the RC filtering circuit, a fixed level value is obtained. (For example, the driving level is 15V for the high level V+, -10V for the low level V-, and 0.6 for the duty cycle. The average value of the output level is 15*0.6-10*0.4=5V). In order to avoid interference between signals, the fixed level output is connected to an isolation circuit (the core is a C87B chip). The isolated voltage value is conditioned by the operational amplifier and sent to the sampling circuit unit of the controller board 400. The level value is used as the input of each sampling circuit, so it can be used to detect whether the function of each sampling circuit is normal.

[0039] Further, such as Figure 3The figure shows the internal circuit of the switch quantity test circuit 600, and the circuit principle is as follows: the control chip opens the circuit output signal KO1 (several signals correspond to several groups of test circuits 2), which is connected to the control coil of the relay J1 after passing through the transistor Q1. One end of the main circuit node of the relay is grounded, and the other end is connected to the input end of the optocoupler U1. The output signal KIN1 of the optocoupler through the resistor is connected to the input signal of the controller. During the test, the controller chip only needs to output a high-level signal to KO1, and the corresponding KIN1 will output the corresponding level jump signal. When the controller detects the corresponding jump of the level, it determines that the circuit function is normal.

[0040] Further, such as Figure 4 The figure shows the test effect diagram displayed by the human-machine interface 303 of the test system. The controller is connected to the test human-machine interaction unit 700 through the communication circuit (CAN / 485 / 232). By testing whether the communication data is sent and received normally, it is determined whether the communication circuit function is normal. At the same time, through the one-key start command, the control system function can be automatically determined by the final result judgment, and the judgment result is displayed in the lower right corner. The entire control system test process is simple and easy to operate, and the test coverage is full.

[0041] Importantly, it should be noted that the construction and arrangement of the present application shown in a plurality of different exemplary embodiments are only exemplary. Although only a few embodiments are described in detail in this disclosure, it should be readily understood by those who refer to this disclosure that many modifications are possible (e.g., the size, scale, structure, shape and proportion of various elements, and parameter values ​​(e.g., temperature, pressure, etc.), installation arrangement, use of materials, color, directional changes, etc.) without substantially departing from the novel teachings and advantages of the subject matter described in the application. For example, the element shown as integrally formed can be composed of multiple parts or elements, the position of the element can be inverted or otherwise changed, and the nature or number or position of the discrete element can be changed or changed. Therefore, all such modifications are intended to be included in the scope of the present invention. The order or sequence of any process or method steps can be changed or reordered according to alternative embodiments. In the claims, any "device plus function" clause is intended to cover the structure of performing the function described herein, and is not only structurally equivalent but also equivalent structure. Without departing from the scope of the present invention, other replacements, modifications, changes and omissions can be made in the design, operating conditions and arrangement of the exemplary embodiments. Therefore, the invention is not limited to a specific embodiment, but extends to numerous modifications still falling within the scope of the appended claims.

[0042] Additionally, in order to provide a concise description of exemplary embodiments, all features of an actual embodiment (ie, those features that are not relevant to the best mode presently contemplated for carrying out the invention or those that are not relevant to implementing the invention) may not be described.

[0043] It will be appreciated that in the development of any actual implementation, as in any engineering or design project, numerous implementation-specific decisions may be made. Such a development effort may be complex and time-consuming, but will be a routine task of design, fabrication, and production for those of ordinary skill having the benefit of this disclosure without undue experimentation.

[0044] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A detection system for a power electronic converter control board, characterized in that: include, An analog quantity test circuit module (100) is connected to the controller board (400), and comprises a drive board (101), an analog quantity circuit input terminal (102), and an analog quantity circuit output terminal (103); A switching quantity test circuit (200) comprising a switching quantity circuit input terminal (201) and a switching quantity circuit output terminal (202); and, A human-computer interaction unit module (300), comprising a computer (301), a communication interface (302) and a human-computer interaction unit interface (303); The controller board (400) comprises a control chip (401), a drive circuit (402), a sampling circuit (403), a communication circuit (404), an output circuit (405) and an input circuit (406); The driving circuit (402) is provided with a driving circuit output end (402a) and a driving circuit input end (402b), and the sampling circuit (403) is provided with a sampling circuit output end (403a) and a sampling circuit input end (403b); The output of the output circuit (405) of the controller card is connected to the input end (203) of the switch quantity test circuit (200) of the automatic detection system, and the output end (204) of the switch quantity test circuit (200) is connected to the input of the input circuit (406) of the controller card; The control chip opens the circuit output signal KO1, which is connected to the control coil of relay J1 after passing through transistor Q1. One end of the main circuit node of the relay is grounded, and the other end is connected to the input end of the optocoupler U1. The output signal KIN1 of the optocoupler through the resistor is connected to the input signal of the controller. During the test, the controller chip only needs to output a high-level signal to KO1, and the corresponding KIN1 will output the corresponding level jump signal. When the controller detects the corresponding level jump, it determines that the circuit function is normal.

2. The detection system for a power electronic converter control board as claimed in claim 1, characterized in that: The drive circuit output end (402a) inside the controller board (400) is connected to the analog circuit input end (102), and the analog circuit output end (103) is connected to the sampling circuit input end (403b) inside the controller board (400).

3. A detection method applied to a power electronic converter control board, characterized in that: The detection system for a power electronic converter control board according to claim 2, and The test steps of the analog quantity test circuit (500) include: After receiving a test start instruction from the human-machine interaction unit (700), the control chip (401) of the controller board (400) inputs a specified PWM pulse wave to the drive circuit (402); After the PWM pulse is output and amplified by the driving circuit (402), it is converted into a corresponding DC signal through an RC capacitor filtering circuit and level conversion in the analog quantity test circuit (500); The DC signal is then sent to the sampling circuit (403) of the controller board (400) after passing through the level isolation conversion circuit.

4. The detection method for a power electronic converter control board as claimed in claim 3, characterized in that: When the number of sampling circuits is greater than the input signal, one set of DC signals may correspond to multiple sampling and conditioning circuits, and the output signal of the sampling circuit (403) of the controller board is sent to the control chip (401) of the controller board for data processing such as A / D conversion.

5. The detection method applied to the control board of the power electronic converter according to claim 4 is characterized in that: The control chip (401) compares the digital value after A / D conversion with the set value. If the result is within the set deviation range, it is automatically determined that the drive unit, sampling unit and control chip of the controller board (400) are normal; If the deviation exceeds the set range, it is automatically determined that the drive unit or sampling unit of the controller board (400) is normal or the control chip is abnormal.

6. The detection method for a power electronic converter control board as claimed in claim 5, characterized in that: The switch quantity test circuit (200) comprises the following test steps: The control chip (401) of the controller card (400) has an output circuit output signal connected to the switch quantity test circuit (200), and the output stage of the test circuit is connected to the input circuit part of the controller card (400); The control chip compares the levels of the output and input signals and if they are consistent, it will automatically determine that the input and output circuits are normal; otherwise, it will determine that the input or output circuits are abnormal.

7. The detection method applied to a power electronic converter control board as claimed in any one of claims 3 to 6, characterized in that: The controller board (400) is connected to the human-machine interaction unit (700) via a communication circuit, and the test data and results are displayed on the human-machine interaction unit interface (303). If the human-machine interaction unit (700) finds a communication anomaly, it determines and displays that the communication circuit of the controller board (400) is abnormal.

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