Power-on self-test detection circuit and method

Abstract

The present invention discloses a power-on self-test detection circuit and method, including: a first voltage source, a voltage conversion device, a processor, and a bus that can supply power to a power circuit, the power circuit includes at least two power electronic devices; the first voltage source is connected to the bus through a voltage conversion device, the voltage conversion device is used to convert the first voltage output by the first voltage source into a pre-charge voltage to supply power to the bus, the pre-charge voltage is not lower than a preset ratio of the second voltage, and the second voltage is the working voltage of the power circuit; the power circuit is connected to the first voltage source through a processor, the processor is used to control the opening and closing of the power electronic device, and detect the output voltage value of the first voltage source; when a short-circuit fault occurs in the power circuit, the output voltage value is less than or equal to the preset voltage threshold, and the short-circuit current value flowing through the power circuit is less than or equal to the preset current threshold. The present application can effectively improve the reliability of circuit self-test on the basis of realizing high-voltage capacitor pre-charging.

Description

Technical Field

[0001] The invention relates to the field of fuel cells, and in particular to a power-on self-test detection circuit and a power-on self-test detection method used for the power-on self-test detection circuit. Background Art

[0002] With the continuous development of the fuel cell field, hydrogen fuel cell systems have been widely used in modern electric vehicles due to their high energy conversion rate, stable operation and low noise. As a key component in the hydrogen fuel cell system, the air compressor plays an important role in the stable operation of the hydrogen fuel cell system.

[0003] The existing air compressor controller will inevitably encounter abnormal conditions during operation, which may lead to system failure. Therefore, it is necessary to detect whether there is a fault in the circuit before applying high voltage, especially to detect whether there is a short circuit in the insulated gate bipolar transistor (IGBT) in the controller. The existing fault detection method is usually based on a diode detection method, such as the patent with application number 201920815804.5, which proposes to detect the controller circuit by setting a diode between the high-voltage circuit and the low-voltage circuit and utilizing its forward conduction and reverse cutoff function. However, this detection method still has the following shortcomings:

[0004] 1. The diode has no isolation function. When the diode breaks down or short-circuits, it is very likely to cause the high-voltage circuit to be connected to the low-voltage circuit, causing the control chip and control board to malfunction;

[0005] 2. When the circuit self-test starts, the current of the power supply charging the capacitor is large, which is likely to lower the battery voltage, thus causing the microcontroller to falsely alarm;

[0006] 3. After the circuit self-test is completed, the high-voltage bus needs to be pre-charged, which takes a long time. Summary of the invention

[0007] In view of the deficiencies in the prior art, the present application provides a power-on self-test detection circuit and method to improve the reliability of circuit self-test.

[0008] In a first aspect, the present application provides a power-on self-test detection circuit, the circuit comprising: a first voltage source (1), a voltage conversion device (2), a processor (3), and a bus (8) capable of supplying power to a power circuit (7), wherein the power circuit (7) comprises at least two power electronic devices;

[0009] The first voltage source (1) is connected to the bus (8) via the voltage conversion device (2), the voltage conversion device (2) being used to convert a first voltage output by the first voltage source (1) into a pre-charging voltage to supply power to the bus (8), the pre-charging voltage being not less than a preset ratio of a second voltage, the second voltage being an operating voltage of the power circuit (7);

[0010] The power circuit (7) is connected to the first voltage source (1) via the processor (3), and the processor (3) is used to control the on and off of the power electronic device and detect the output voltage value of the first voltage source (1); when a short-circuit fault occurs in the power circuit (7), the output voltage value is less than or equal to a preset voltage threshold, and the short-circuit current value flowing through the power circuit (7) is less than or equal to a preset current threshold.

[0011] In some embodiments, the circuit further includes a pre-charging circuit, the first voltage source (1) is connected to the bus (8) via the pre-charging circuit, and the pre-charging circuit includes a first circuit formed by connecting a first switching element (41) and an impedance element (5) in series.

[0012] In some embodiments, the pre-charging loop further includes a second circuit connected in parallel with the first circuit, the second circuit including a second switching element (42).

[0013] In some embodiments, the voltage conversion device (2) is an isolated boost device.

[0014] In some embodiments, the first switching element (41) and / or the second switching element (42) are configured as controllable switching elements or uncontrollable switching elements.

[0015] In a second aspect, the present application further provides an air compressor controller, which includes a power-on self-test detection circuit as described above.

[0016] In a third aspect, the present application also provides a hydrogen fuel cell system, which includes the air compressor controller as described above.

[0017] In a fourth aspect, the present application further provides a power-on self-test detection method, which is used for a power-on self-test detection circuit, wherein the power-on self-test detection circuit is the power-on self-test detection circuit described above, and the power-on self-test detection circuit:

[0018] Obtaining the bus voltage of the power-on self-test detection circuit;

[0019] If the bus voltage reaches the pre-charge voltage, the power electronic device in the power circuit is controlled to be turned on, and the pre-charge voltage is obtained by converting the first voltage output by the first voltage source by the voltage conversion device;

[0020] Based on the turned-on power electronic device, detecting the output voltage value of the first voltage source;

[0021] If the output voltage value is less than or equal to a preset voltage threshold within a first preset time, it is determined that the power circuit is faulty.

[0022] In some embodiments, before obtaining the bus voltage of the bus, the method also includes: determining whether the power-on self-test detection circuit satisfies a preset charging trigger condition; generating a charging instruction when the power-on self-test detection circuit satisfies the charging trigger condition; sending the charging instruction to a controllable switching element in the power-on self-test detection circuit, the pre-charging instruction being used to instruct the controllable switching element to close or open so that the first voltage source can supply power to the bus through the voltage conversion device until the bus voltage of the bus reaches the pre-charging voltage.

[0023] In some embodiments, the controllable switching element includes a first contact switch and / or a second contact switch, and the charging instruction is a first charging instruction or a second charging instruction. The first charging instruction is used to instruct the first contact switch to close, and the second charging instruction is used to instruct the first contact switch to close and the second contact switch to open, and after the bus voltage reaches a limited charging voltage, the second contact switch is instructed to close and the first contact switch to open.

[0024] In some embodiments, if the bus voltage reaches the pre-charge voltage, a fault detection instruction is generated; the fault detection instruction is sent to the drive unit, and the fault detection instruction is used to instruct the drive unit to turn on the power electronic devices in the power circuit in sequence.

[0025] In some embodiments, the power-on self-test detection circuit includes a second voltage source and an active switching element. After the output voltage value of the first voltage source is detected based on the turned-on power electronic device, the method further includes: if the output voltage value is greater than the preset voltage threshold within a first preset time, generating a control instruction; sending the control instruction to the active switching element, the first control instruction is used to instruct the active switching element to close, so that the second voltage source can supply power to the bus when the active switching element is closed.

[0026] The power-on self-test detection circuit provided in the present application can realize circuit self-test after controlling the on and off of power electronic devices in the power circuit by converting the first voltage output by the first voltage source into bus power supply, thereby effectively improving the reliability of circuit self-test. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0028] Figure 1 A schematic diagram of the structure of a power-on self-test detection circuit provided in an embodiment of the present application;

[0029] Figure 2 A schematic diagram of the structure of another power-on self-test detection circuit provided in an embodiment of the present application;

[0030] Figure 3 A flowchart of a power-on self-test method provided in an embodiment of the present application. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0032] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0033] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or mutual communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0034] The disclosure below provides many different embodiments or examples to realize the different structures of the present application. In order to simplify the disclosure of the present application, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present application. In addition, the present application can repeat reference numbers and / or reference letters in different examples, and this repetition is for the purpose of simplification and clarity, which itself does not indicate the relationship between the various embodiments and / or settings discussed. In addition, the various specific processes and material examples provided by the present application, but those of ordinary skill in the art can appreciate the application of other processes and / or the use of other materials.

[0035] like Figure 1 As shown, in one embodiment, the present application provides a power-on self-test detection circuit, comprising: a first voltage source (1), a voltage conversion device (2), a processor (3), and a bus (8) capable of supplying power to a power circuit (7), wherein the power circuit (7) comprises at least two power electronic devices;

[0036] The first voltage source (1) is connected to the bus (8) via a voltage conversion device (2), the voltage conversion device (2) is used to convert a first voltage output by the first voltage source (1) into a pre-charge voltage to supply power to the bus (8), the pre-charge voltage is not lower than a preset ratio of a second voltage, and the second voltage is the working voltage of the power circuit (7); the power circuit (7) is connected to the first voltage source (1) via a processor (3), the processor (3) is used to control the on and off of the power electronic device and detect the output voltage value of the first voltage source (1); when a short-circuit fault occurs in the power circuit (7), the output voltage value is less than or equal to a preset voltage threshold, and the short-circuit current value flowing through the power circuit (7) is less than or equal to a preset current threshold.

[0037] Specifically, the power electronic device is an IGBT transistor, Figure 1The power electronic device shown includes 6 IGBT transistors Q1, Q2, Q3, Q4, Q5 and Q6. IGBT transistors are composite fully controlled voltage-driven power semiconductor devices composed of bipolar junction transistors (BJT) and metal-oxide-semiconductor field-effect transistors (MOS). They have the advantages of high input impedance of metal-oxide-semiconductor field-effect transistors (MOSFET) and low on-state voltage drop of giant transistors (GTR). They are very suitable for use in converter systems with a DC voltage of 600V or above, such as AC motors, permanent magnet synchronous motors, frequency converters, switching power supplies, lighting circuits, traction drives, and other fields. The three-phase inverter circuit composed of IGBT insulated gate bipolar transistors can reduce current fluctuations and torque ripples. The power module (7) is a three-phase inverter circuit, which integrates at least two power electronic devices. After the integration of multiple power electronic devices, the power module (7) has three connection ends. Among them, the first connection end of the power module (7) is connected to the bus (8), the second connection end of the power module (7) is connected to the processor (3) through the drive unit (6), and the third connection end of the power module (7) is grounded.

[0038] More specifically, the processor (3) includes at least one of a central processing unit (CPU), an electronic control unit (ECU), a microcontroller unit (MCU), a memory protection unit (MPU) and an integrated circuit chip (System-on-a-Chip, SOC). It is understandable that in other embodiments, the processor (3) can also be other processors that meet the circuit requirements, and the present application does not impose specific restrictions on the processor (3). The drive unit (6) is a unit module for driving the power electronics in the power module (7), and the drive unit (6) can also be at least one of a central processing unit, an electronic control unit, a microcontroller unit, a memory protection unit and an integrated circuit chip. The bus (8) refers to a common path to which multiple devices are connected in the form of parallel branches. The voltage conversion device (2) is a boost device, and the first voltage output by the first voltage source (1) is 12V to 32V.

[0039] Further, the second voltage is the working voltage of the power circuit (7), and the working voltage in the embodiment of the present application can be 500V (in other embodiments, it can be 400V to 750V). When the preset ratio is 70%, the pre-charge voltage is 350V-500V. If the actual pre-charge voltage also has an upper limit pre-threshold value, such as the pre-charge voltage is not lower than the first preset ratio of the second voltage, and is not higher than the second preset ratio of the second voltage, then when the first preset ratio is 10% and the second preset ratio is 80%, the pre-charge voltage is 100V-400V, and the pre-charge voltage lower than the working voltage is used to power the bus, so that the high-voltage capacitor pre-charging function can be realized while completing the circuit self-check, thereby omitting the pre-charging circuit of the high-voltage bus in the original circuit. It can be understood that the preset ratio can be set according to the actual application requirements. If the bus (8) needs to be powered by more than 70% of the actual required power, the preset ratio can be set to 70%.

[0040] Furthermore, the circuit can also realize its self-checking function, that is, the processor (3) can control the opening and closing of the power electronic devices in the power module (7), and detect the output voltage value of the first voltage source (1) in real time to realize the fault detection of its three-phase inverter circuit. The principle is that as the power electronic devices are controlled by the processor (3) to be turned on one by one, if one of the power electronic devices has a fault, turning on its opposite tube device will cause the bridge arm to be instantly connected, that is, it will trigger the first voltage source (1) to provide a larger current. However, since the power of the first voltage source (1) is relatively small and the power supply capacity is limited, the output voltage of the first voltage source (1) will be pulled to the undervoltage threshold at this time, that is, the output voltage value of the first voltage source (1) is less than or equal to the preset voltage threshold, and the short-circuit current value flowing through the power circuit (7) is less than or equal to the preset current threshold. At this time, the processor (3) can not only realize circuit self-checking by detecting the output voltage of the first voltage source (1), but also detect and locate the specific faulty power electronic device.

[0041] It should be noted that, in the embodiment of the present application, the fault signal of the power circuit (7) (undervoltage signal of the first voltage source) can be detected by the processor (3), so as to determine the specific faulty power electronic device in the power circuit (7); on the contrary, if the voltage output by the first voltage source (1) remains stable after the drive unit (6) is instructed by the processor (3) to turn on the power electronic devices in sequence, then it can be determined that the power circuit (7) has no fault for the time being, and the processor (3) can continue to perform subsequent operations according to business requirements.

[0042] The power-on self-test detection circuit provided in this embodiment can realize circuit self-test after controlling the on and off of power electronic devices in the power circuit by converting the first voltage output by the first voltage source into bus power supply, thereby effectively improving the reliability of circuit self-test.

[0043] In one embodiment, the power-on self-test detection circuit further includes a pre-charging circuit, and the first voltage source (1) can be connected to the bus (8) via the pre-charging circuit, and the pre-charging circuit includes a first circuit formed by a first switch element (41) and an impedance element (5) connected in series.

[0044] The first switch element (41) is a switch element at the control end of the relay (4), and the impedance element (5) is a current-limiting resistor in the pre-charging circuit, which is used to achieve electrical isolation between strong and weak electricity.

[0045] For details, see Figure 1 The control end of the relay (4) is respectively connected to the processor (3) and the ground end of the first voltage source (1); the output end of the relay (4), namely the first switch element (41), is respectively connected to the current limiting resistor (5) and the boost end of the voltage conversion device (2); the first voltage source (1) is sequentially connected to the bus (8) through the voltage conversion device (2), the first switch element (41) and the current limiting resistor (5) to supply power to the bus (8).

[0046] More specifically, since the relay (4) is actually an "automatic switch" that uses a smaller current to control a larger current, by adding the relay (4) to the power-on self-test detection circuit, after the processor (3) controls it to close, the current in the pre-charging circuit can be limited under the action of the current limiting resistor (4), that is, there will be no excessive charging current to lower the output voltage of the first voltage source (1), thereby preventing the processor (3) from erroneously determining that the power circuit (7) is short-circuited (voltage drops) and issuing a fault alarm.

[0047] The power-on self-test detection circuit provided in this embodiment can avoid the processor from misjudging the power circuit fault by setting a pre-charging circuit.

[0048] In one embodiment, the pre-charging circuit mentioned in the above embodiment further includes a second circuit connected in parallel with the first circuit, and the second circuit includes a second switch element (42).

[0049] The second switch element (42) is a switch element at the control end of the relay (4).

[0050] For details, see Figure 2 The output end of the relay (4) includes a first switch element (41) and a second switch element (42). A second switch element (42) is connected in parallel to the first circuit, so that: when the pre-charging voltage controlled by the first switch element (41) reaches a certain level (reaches a preset voltage threshold), the first switch element (41) is disconnected and only the second circuit is used to charge the bus (8), thereby increasing the pre-charging speed of the power-on self-test detection circuit, thereby shortening the circuit self-test and pre-charging time.

[0051] It should be noted that the power-on self-test detection circuit provided in the present application has circuit pre-charging and power-on self-test functions. Without the pre-charging function, the active switch element (10) on the busbar (8) is closed at a moment sufficient to cause the circuit capacitor to generate an instantaneous high voltage and damage other components; without the self-test function, the power electronic device and other components will be damaged secondary when the high voltage is powered on.

[0052] The power-on self-test detection circuit provided in this embodiment can shorten the circuit self-test and pre-charge time and improve the reliability and safety of the circuit self-test by setting a pre-charge circuit with dual parallel circuits while avoiding the processor from misjudging the power circuit fault.

[0053] In one embodiment, the voltage conversion device (2) is an isolation boost device.

[0054] Specifically, the voltage conversion device (2) can be a 24V (or 12V to 32V) low voltage to high voltage isolation boost device, and the low voltage to high voltage isolation boost device is used to isolate and convert the first voltage output by the first voltage source (1) into a preset high voltage. It can be understood that in other embodiments, the voltage conversion device (2) can also be a 15V low voltage to high voltage isolation boost device among 12V to 32V, that is, the low voltage value at this time is determined by the first voltage source (1). If the output voltage of the first voltage source (1) is 15V, the voltage conversion device (2) must be a 15V to high voltage isolation boost device; if the output voltage of the first voltage source (1) is 24V (or 12V to 32V), the voltage conversion device (2) must be a 24V low voltage to high voltage isolation boost device. Therefore, the present application does not impose specific restrictions on the value of the low voltage required in the circuit.

[0055] The power-on self-test detection circuit provided in this embodiment converts the voltage output by the first voltage source into a pre-charge voltage by providing an isolation boost device, thereby improving the reliability and safety of the circuit self-test while ensuring the safety of pre-charge.

[0056] In one embodiment, the first switch element (41) and / or the second switch element (42) are configured as controllable switch elements or uncontrollable switch elements.

[0057] Specifically, the uncontrollable switch element may be a diode, and the controllable switch element may be a Figure 1-2 The switch element shown, the controllable switch element can be controlled by a processor (3).

[0058] The power-on self-test detection circuit provided in this embodiment can control the voltage not to be reversed by setting the switch element as a controllable switch element or an uncontrollable switch element, thereby improving the reliability of the circuit self-test.

[0059] In one of the embodiments, the present application also provides an air compressor controller, which includes the power-on self-test detection circuit described in any of the above embodiments.

[0060] In one embodiment, the present application also provides a hydrogen fuel cell system, which includes an air compressor controller as described in the above embodiment. The hydrogen fuel cell system also includes a fuel cell controller and a hydrogen return pump controller connected to the air compressor controller. It can be understood that the fuel cell controller is the control "brain" of the fuel cell engine system, which mainly realizes online detection, real-time control and fault diagnosis of the fuel cell system to ensure stable and reliable operation of the system.

[0061] like Figure 3 As shown, in one embodiment, the present application embodiment provides a power-on self-test detection method. This embodiment mainly applies this method to the above Figure 1 Take the processor (3) in as an example. Figure 3 The power-on self-test method specifically includes steps S301 to S303, which are as follows:

[0062] S301, obtaining the bus voltage of the power-on self-test detection circuit;

[0063] S302, if the bus voltage reaches a pre-charge voltage, controlling the power electronic device in the power circuit to turn on, wherein the pre-charge voltage is obtained by converting the first voltage output by the first voltage source by the voltage conversion device;

[0064] S303, detecting an output voltage value of the first voltage source based on the turned-on power electronic device;

[0065] S304: If the output voltage value is less than or equal to a preset voltage threshold within a first preset time, it is determined that the power circuit is faulty.

[0066] For details, see Figure 1The power-on sequence of the power-on self-test detection circuit is to first turn on the low voltage and then the high voltage. Before the active switch element (10) is closed, the first voltage source (1) first supplies power to the bus (8). After the processor (3) determines that the logic function is normal, it can send a signal to control the first switch element (41) to close. At this time, the circuit starts to be powered on and pre-charged through the impedance element (5). The pre-charging can be ended when the bus voltage reaches the pre-charging voltage. After the pre-charging is completed, the processor (3) controls the drive unit (6) to turn on the power electronic devices in the power circuit (7) in sequence. If a power electronic device has a fault, turning on its pair of tubes will cause the bridge arm to be instantly connected. That is, at this time, the first voltage source (1) needs to provide a large current, but due to its limited power supply capacity, the voltage of the first voltage source (1) will be pulled down to a preset undervoltage threshold, resulting in its output voltage value being less than or equal to the preset voltage threshold within a first preset time. The undervoltage signal is detected by the drive unit (6) and sent to the processor (3), thereby determining which power electronic device has a short circuit.

[0067] For example, the counterpart of the power electronic device Q1 is Q4. If Q1 fails, Q4 will be instantly turned on due to its short circuit. At this time, the first voltage source (1) needs to provide a larger current than before. However, the power provided by the first voltage source (1) is limited, and an increase in current will inevitably lead to a decrease in voltage. Therefore, the processor (3) can control each power electronic device to start up in turn, and analyze the changes in the output voltage of the first voltage source (1), so as to detect the specific faulty power electronic device.

[0068] In one embodiment, before step S301, the following steps are specifically included:

[0069] S401, determining whether the power-on self-test detection circuit meets a preset charging trigger condition;

[0070] S402, generating a charging instruction when the power-on self-test detection circuit meets the charging trigger condition;

[0071] S403, sending the charging instruction to the controllable switch element in the power-on self-test detection circuit, the pre-charging instruction is used to instruct the controllable switch element to close or open, so that the first voltage source can supply power to the bus through the voltage conversion device until the bus voltage of the bus reaches the pre-charging voltage.

[0072] The charging instruction is an instruction for instructing the switch to close to charge the bus.

[0073] For details, see Figure 1Before executing the circuit pre-charging operation, it is first necessary to determine whether the logic function of the circuit or the controller in which the circuit is located is normal. When the first voltage source (1) starts to supply power and the processor (3) determines that the logic function is normal, a charging instruction can be generated. The charging instruction will be sent by the processor (3) to the controllable switch element in the circuit, such as Figure 2 The first switch element (41) and / or the second switch element (42) shown are used to instruct the controllable switch element to close or open to supply power to the bus (8) until the bus voltage reaches the pre-charge voltage.

[0074] In one embodiment, the controllable switch element includes a first contact switch and / or a second contact switch, the charging instruction is a first charging instruction or a second charging instruction, the first charging instruction is used to instruct the first contact switch to close, the second charging instruction is used to instruct the first contact switch to close and the second contact switch to open, and after the bus voltage reaches a limited charging voltage, the second contact switch is instructed to close and the first contact switch to open.

[0075] For details, see Figure 2 When the controllable switch element only includes the first contact switch, the charging instruction is a first charging instruction, which can be used to instruct the first contact switch to close, so that the first voltage source (1) can sequentially supply power to the bus (8) through the voltage conversion device (2) and the impedance element (5); when the controllable switch element only includes the first contact switch and the second contact switch, the charging instruction is a second charging instruction, which can be used to instruct the first contact switch to close and the second contact switch to open, so that after the first voltage source (1) supplies power to the bus (8) so that its bus voltage reaches the limited charging voltage, the first contact switch is opened and the second contact switch is closed, so that the first voltage source (1) continues to supply the remaining voltage to the bus (8) until the bus voltage reaches the pre-charging voltage.

[0076] In one embodiment, the power-on self-test detection circuit includes a driving unit, and step S302 specifically includes the following steps:

[0077] S501, if the bus voltage reaches the pre-charging voltage, a fault detection instruction is generated;

[0078] S502: Send the fault detection instruction to the drive unit, where the fault detection instruction is used to instruct the drive unit to turn on power electronic devices in the power circuit in sequence.

[0079] For details, see Figure 1After detecting that the bus voltage reaches the pre-charging voltage, the processor (3) can generate a fault detection instruction and send the instruction to the drive unit (6), so that the drive unit (6) turns on the power electronic devices in the power circuit (7) one by one to achieve circuit fault detection.

[0080] In one embodiment, the power-on self-test detection circuit includes a second voltage source and an active switch element, and specifically includes the following steps after step S303:

[0081] S601, if the output voltage value is greater than the preset voltage threshold within a first preset time, generating a control instruction;

[0082] S602: Send the control instruction to the active switch element, where the first control instruction is used to instruct the active switch element to close, so that the second voltage source supplies power to the bus when the active switch element is closed.

[0083] For details, see Figure 1 After the processor (3) instructs the drive unit (6) to turn on the power electronic devices one by one, it is also necessary to detect the output voltage value of the first voltage source in real time. If the output voltage value is greater than a preset voltage threshold within a first preset time, a control instruction is generated and sent to the active switch element (10) to control its closing, so that after the active switch element (10) is closed, the second voltage source (9) supplies power to the bus (8), and at this time the circuit and the load added to the circuit can operate normally.

[0084] The above-mentioned power-on self-test detection method sets the charging trigger condition so that the circuit generates a charging instruction when the condition is met, and then uses the charging instruction to control the closing or opening of the controllable switching element to power the bus. On the basis of realizing the pre-charging of the high-voltage capacitor, it can effectively improve the reliability of the circuit self-test.

[0085] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0086] The above is a detailed introduction to a power-on self-test detection circuit and method provided in an embodiment of the present application. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the technical solution and core idea of ​​the present application. Ordinary technicians in this field should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some of the technical features therein with equivalents; and these modifications or replacements do not cause the essence of the corresponding technical solution to deviate from the scope of the technical solution of the embodiments of the present application.

Claims

1. A power-on self-test detection circuit, characterized in that: The circuit comprises: A first voltage source (1), a voltage conversion device (2), a processor (3), and a bus (8) capable of supplying power to a power circuit (7), wherein the power circuit (7) comprises at least two power electronic devices, wherein the power electronic devices comprise insulated gate bipolar transistors; The first voltage source (1) is connected to the bus (8) via the voltage conversion device (2), the voltage conversion device (2) being used to convert a first voltage output by the first voltage source (1) into a pre-charging voltage to supply power to the bus (8), the pre-charging voltage being not less than a preset ratio of a second voltage, the second voltage being an operating voltage of the power circuit (7); The power circuit (7) is connected to the first voltage source (1) via the processor (3), and the processor (3) is used to control the on and off of the power electronic device and detect the output voltage value of the first voltage source (1); when a short-circuit fault occurs in the power circuit (7), the output voltage value is less than or equal to a preset voltage threshold, and the short-circuit current value flowing through the power circuit (7) is less than or equal to a preset current threshold; A pre-charging circuit, wherein the first voltage source (1) is connected to the busbar (8) via the pre-charging circuit, and the pre-charging circuit comprises a first circuit formed by a first switching element (41) and an impedance element (5) connected in series.

2. The power-on self-test detection circuit according to claim 1, characterized in that: The pre-charging loop further comprises a second circuit connected in parallel with the first circuit, the second circuit comprising a second switching element (42).

3. The power-on self-test detection circuit according to claim 1, characterized in that: The voltage conversion device (2) is an isolation boosting device.

4. The power-on self-test detection circuit according to any one of claims 1 or 2, characterized in that: The first switching element (41) and / or the second switching element (42) are configured as controllable switching elements or uncontrollable switching elements.

5. A power-on self-test detection method, used for a power-on self-test detection circuit, characterized in that: The power-on self-test detection circuit is the power-on self-test detection circuit according to any one of claims 1 to 4, and the method comprises: Obtaining the bus voltage of the power-on self-test detection circuit; If the bus voltage reaches the pre-charge voltage, the power electronic device in the power circuit is controlled to be turned on, and the pre-charge voltage is obtained by converting the first voltage output by the first voltage source by the voltage conversion device; Based on the turned-on power electronic device, detecting the output voltage value of the first voltage source; If the output voltage value is less than or equal to a preset voltage threshold within a first preset time, it is determined that the power circuit is faulty.

6. The power-on self-test method according to claim 5, characterized in that: Before obtaining the bus voltage of the bus, the method further includes: Determining whether the power-on self-test detection circuit meets a preset charging trigger condition; When the power-on self-test detection circuit meets the charging trigger condition, generating a charging instruction; The charging instruction is sent to the controllable switch element in the power-on self-test detection circuit, and the pre-charging instruction is used to instruct the controllable switch element to close or open so that the first voltage source can supply power to the bus through the voltage conversion device until the bus voltage of the bus reaches the pre-charging voltage.

7. The power-on self-test method according to claim 6, characterized in that: When the controllable switch element includes a first contact switch, the charging instruction is a first charging instruction; When the controllable switch element includes a first contact switch and a second contact switch, the charging instruction is a second charging instruction; Among them, the first charging instruction is used to instruct the first contact switch to close, and the second charging instruction is used to instruct the first contact switch to close and the second contact switch to open, and after the bus voltage reaches the limited charging voltage, the second contact switch is instructed to close and the first contact switch to open.

8. The power-on self-test method according to claim 5, characterized in that: The power-on self-test detection circuit includes a driving unit, and if the bus voltage reaches the pre-charge voltage, the power electronic device in the power circuit is controlled to be turned on, including: If the bus voltage reaches the pre-charge voltage, a fault detection instruction is generated; The fault detection instruction is sent to the drive unit, where the fault detection instruction is used to instruct the drive unit to turn on the power electronic devices in the power circuit in sequence.

9. The power-on self-test method according to claim 5, characterized in that: The power-on self-test detection circuit includes a second voltage source and an active switch element. After the output voltage value of the first voltage source is detected based on the turned-on power electronic device, the method further includes: If the output voltage value is greater than the preset voltage threshold within the first preset time, generating a control instruction; The control instruction is sent to the active switch element, where the control instruction is used to instruct the active switch element to close, so that the second voltage source supplies power to the bus when the active switch element is closed.

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