An inverter control method, device and equipment

Abstract

The application discloses an inverter control method, device and equipment, to solve the problem that the switching device in the inverter may be damaged due to the existence of delay. The method comprises the following steps: in the first switching period, determining the current change duration according to the time when the inductor current is equal to the first current threshold and the time when the inductor current is equal to the second current threshold, determining the current change rate according to the current change duration, the first current threshold and the second current threshold, if the current change rate is greater than a preset threshold, then reducing and adjusting the first current threshold and the second current threshold, and in the second switching period, using the reduced current threshold to control the switching tube. Since the current threshold is reduced and adjusted when the current rises rapidly, and the reduced current threshold is used to control the switching tube in the next switching period, compared with using the current threshold before the reduction and adjustment, the risk of damaging the switching tube can be reduced, and the reliability of the inverter is improved.

Description

Technical Field

[0001] This invention relates to the field of inverter technology, and in particular to an inverter control method, apparatus and equipment. Background Technology

[0002] Current limiting technology is a very important protection technology for inverters. This technology can limit the output current when there is a large overload, sudden load or output short circuit, thereby effectively protecting the switching devices and improving the reliability and safety of the inverter.

[0003] Currently, the common method for limiting output current is to set a current threshold as the current limiting point. When the inductor current exceeds the current threshold, the switching devices are blocked in a certain order. When the inductor current drops below the current threshold, the switching devices are released to allow them to work normally.

[0004] Since the blocking and releasing of switching devices require a certain timing sequence, taking a typical type I three-level circuit as an example, when blocking, the outer tube needs to be blocked first, and the inner tube needs to be blocked after the outer tube is reliably blocked. This requires setting two current thresholds as the current limiting points of the outer tube and the inner tube respectively, and the current threshold of the outer tube current limiting point is lower than the current threshold of the inner tube current limiting point.

[0005] When blocking a switching device, due to delays in hardware processing, software processing, the action of the switching device, and the waiting time for the inner tube to reliably block the outer tube, the actual current when the switching device is blocked after the delay will exceed the theoretical current threshold to varying degrees, which may pose a risk of damaging the switching device. Summary of the Invention

[0006] This invention provides an inverter control method, apparatus, and device to solve the problem that switching devices in inverters may be damaged due to time delays in the prior art.

[0007] In a first aspect, embodiments of the present invention provide an inverter control method, the method comprising:

[0008] In the first switching cycle, the duration of current change is determined based on the moment when the inductor current in the inverter equals the first current threshold and the moment when the inductor current equals the second current threshold.

[0009] The rate of change of current is determined based on the duration of the current change, the first current threshold, and the second current threshold.

[0010] If the rate of change of current is greater than a preset threshold, then the first current threshold is reduced to obtain a third current threshold, and the second current threshold is reduced to obtain a fourth current threshold.

[0011] In the second switching cycle, the switching transistors in the inverter are controlled using the third current threshold and the fourth current threshold;

[0012] Wherein, the first current threshold is less than the second current threshold, and the first switching cycle is earlier than the second switching cycle.

[0013] In one possible implementation, during the first switching cycle, the method further includes:

[0014] When the inductor current is equal to the first current threshold, the first switch corresponding to the first current threshold is turned off.

[0015] When the inductor current is equal to the second current threshold, the second switch corresponding to the second current threshold is turned off.

[0016] In one possible implementation, during the second switching cycle, the switching transistors in the inverter are controlled using the third current threshold and the fourth current threshold, including:

[0017] When the inductor current is equal to the third current threshold, the first switch corresponding to the first current threshold is turned off.

[0018] When the inductor current is equal to the fourth current threshold, the second switch corresponding to the second current threshold is turned off.

[0019] In one possible implementation, after controlling the switching transistors in the inverter using the third and fourth current thresholds during the second switching cycle, the method further includes:

[0020] In the third switching cycle, if the rate of change of current is less than or equal to the preset threshold, the third current threshold is increased to obtain the fifth current threshold, and the fourth current threshold is increased to obtain the sixth current threshold.

[0021] In the fourth switching cycle, the switching transistors in the inverter are controlled using the fifth current threshold and the sixth current threshold;

[0022] Wherein, the second switching cycle is earlier than the third switching cycle, the third switching cycle is earlier than the fourth switching cycle, and the fifth current threshold is less than the sixth current threshold.

[0023] In one possible implementation, the step of increasing the third current threshold to obtain a fifth current threshold and increasing the fourth current threshold to obtain a sixth current threshold during the third switching cycle includes:

[0024] In the third switching cycle, if the current change rate is less than or equal to the preset threshold, the third current threshold is increased after a preset time to obtain the fifth current threshold, and the fourth current threshold is increased after the preset time to obtain the sixth current threshold.

[0025] In one possible implementation, during the third switching cycle, the method further includes:

[0026] When the inductor current is equal to the third current threshold, the first switch corresponding to the first current threshold is turned off.

[0027] When the inductor current is equal to the fourth current threshold, the second switch corresponding to the second current threshold is turned off.

[0028] In one possible implementation, the second current threshold is less than the inductor current of the inverter when the inverter is short-circuited.

[0029] In a second aspect, embodiments of the present invention provide an inverter control device, the device comprising:

[0030] The first determining module is used to determine the duration of current change in the first switching cycle based on the time when the inductor current in the inverter is equal to a first current threshold and the time when the inductor current is equal to a second current threshold.

[0031] The second determining module is used to determine the rate of change of current based on the duration of the current change, the first current threshold, and the second current threshold.

[0032] An adjustment module is used to reduce the first current threshold to obtain a third current threshold and reduce the second current threshold to obtain a fourth current threshold if the rate of change of the current is greater than a preset threshold.

[0033] A control module is configured to control the switching transistors in the inverter using the third current threshold and the fourth current threshold during a second switching cycle.

[0034] Wherein, the first current threshold is less than the second current threshold, and the first switching cycle is earlier than the second switching cycle.

[0035] In one possible implementation, during the first switching cycle, the control module is further configured to:

[0036] When the inductor current is equal to the first current threshold, the first switch corresponding to the first current threshold is turned off.

[0037] When the inductor current is equal to the second current threshold, the second switch corresponding to the second current threshold is turned off.

[0038] In one possible implementation, the control module is specifically used for:

[0039] When the inductor current is equal to the third current threshold, the first switch corresponding to the first current threshold is turned off.

[0040] When the inductor current is equal to the fourth current threshold, the second switch corresponding to the second current threshold is turned off.

[0041] In one possible implementation, after controlling the switching transistors in the inverter using the third and fourth current thresholds during the second switching cycle, the adjustment module is further configured to:

[0042] In the third switching cycle, if the rate of change of current is less than or equal to the preset threshold, the third current threshold is increased to obtain the fifth current threshold, and the fourth current threshold is increased to obtain the sixth current threshold.

[0043] In the fourth switching cycle, the switching transistors in the inverter are controlled using the fifth current threshold and the sixth current threshold;

[0044] Wherein, the second switching cycle is earlier than the third switching cycle, the third switching cycle is earlier than the fourth switching cycle, and the fifth current threshold is less than the sixth current threshold.

[0045] In one possible implementation, the adjustment module is specifically used for:

[0046] In the third switching cycle, if the rate of change of current is less than or equal to the preset threshold, the third current threshold is increased after a preset time to obtain the fifth current threshold, and the fourth current threshold is increased after the preset time to obtain the sixth current threshold.

[0047] In one possible implementation, during the third switching cycle, the control module is further configured to:

[0048] When the inductor current is equal to the third current threshold, the first switch corresponding to the first current threshold is turned off.

[0049] When the inductor current is equal to the fourth current threshold, the second switch corresponding to the second current threshold is turned off.

[0050] In one possible implementation, the second current threshold is less than the inductor current of the inverter when the inverter is short-circuited.

[0051] Thirdly, embodiments of the present invention provide an inverter control device, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps of the inverter control method described in any one of the first aspects.

[0052] Fourthly, embodiments of the present invention provide a computer storage medium storing computer instructions that, when executed on a computer, cause the computer to perform the steps of the inverter control method as described in any one of the first aspects.

[0053] The beneficial effects of this invention are as follows:

[0054] The inverter control method, apparatus, and device provided by this invention, in the first switching cycle, determine the current change duration based on the times when the inductor current in the inverter equals a first current threshold and the times when the inductor current equals a second current threshold. Based on the current change duration, the first current threshold, and the second current threshold, determine the current change rate. If the current change rate is greater than a preset threshold, both the first and second current thresholds are reduced. In the second switching cycle, the reduced two current thresholds are used to control the corresponding switching transistors in the inverter. The first current threshold is less than the second current threshold, and the first switching cycle is earlier than the second switching cycle. A current change rate greater than the preset threshold indicates a rapid current increase. To protect the switching transistors and the inverter, the current thresholds are reduced, and the reduced two current thresholds are used to control the switching transistors in the inverter in the next switching cycle. Compared to using a smaller current threshold to control the switching transistors when the current increases rapidly, this reduces the risk of damage to the switching transistors, thereby reducing the risk of inverter damage and improving inverter reliability. Attached Figure Description

[0055] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0056] Figure 1 A schematic diagram of a type I three-level inverter structure is provided for related technologies;

[0057] Figure 2 A schematic diagram of the inverter control process provided for related technologies;

[0058] Figure 3 A flowchart illustrating an inverter control method provided in an embodiment of the present invention;

[0059] Figure 4 A waveform diagram illustrating current rise is provided for an embodiment of the present invention;

[0060] Figure 5 A flowchart illustrating a control system dynamically adjusting a current threshold, provided as an embodiment of the present invention;

[0061] Figure 6 This is a schematic diagram of the overall process of an inverter control method provided in an embodiment of the present invention;

[0062] Figure 7 This is a schematic diagram of the structure of an inverter control device provided in an embodiment of the present invention;

[0063] Figure 8 This is a schematic diagram of the structure of an inverter control device provided in an embodiment of the present invention;

[0064] Figure 9 This is a schematic diagram of a program product for inverter control provided in an embodiment of the present invention. Detailed Implementation

[0065] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0066] like Figure 1 The diagram shown illustrates a type I three-level inverter structure provided by related technologies. When performing current limiting protection on this inverter, the outer transistors (Q1 and Q4) are typically blocked first. After the outer transistors are reliably blocked, the inner transistors (Q2 and Q3) are then blocked. This requires setting two current thresholds as the current limiting points for the inner and outer transistors, respectively. The current threshold for the outer transistor current limiting point is lower than the current threshold for the inner transistor current limiting point.

[0067] like Figure 1 The current limiting function of the type I three-level inverter shown is usually implemented by the software of the control system, such as... Figure 2As shown, the control system outputs the external transistor current threshold and the internal transistor current threshold, respectively, which are compared with the inductor current sampling value by an external comparator or the control chip. If the inductor current sampling value exceeds or falls below the current threshold, it will feed back different signals to the control system. The control system will then block (turn off) or unlock (turn on) the internal or external transistor of the Type I three-level inverter according to the programmed logic. The current threshold is controlled by the control system software. In addition, the control system will output drive signals to drive the three-level circuit to work.

[0068] The inductor current output by the inverter rises or falls approximately linearly within a switching cycle. When the current rises rapidly, due to delays in the blocking of switching devices (such as hardware delays, software delays, switching transistor operation delays, and the delay of the inner transistor waiting for the outer transistor to reliably block), the inductor current will continuously exceed the current thresholds of both the outer and inner transistors before the switching devices are finally blocked. Therefore, the actual blocked inductor current may exceed the current threshold, posing a risk of damage to the switching transistors and the equipment.

[0069] Furthermore, the current rise rate varies for different types of overloads. After a delay, the actual current when the switch is blocked will exceed the current threshold to varying degrees. In particular, the current rise rate is the fastest under short-circuit conditions, and the actual current when the switch is blocked will be even greater. Therefore, the risk of damage to the switching devices and equipment is greater.

[0070] To address the above problems, embodiments of the present invention provide an inverter control method, such as... Figure 3 As shown, the method includes:

[0071] S301. In the first switching cycle, the duration of current change is determined based on the moment when the inductor current in the inverter is equal to the first current threshold and the moment when the inductor current is equal to the second current threshold.

[0072] S302. Determine the rate of change of current based on the duration of current change, the first current threshold, and the second current threshold;

[0073] S303. If the rate of change of current is greater than a preset threshold, the first current threshold is reduced to obtain a third current threshold, and the second current threshold is reduced to obtain a fourth current threshold.

[0074] S304. In the second switching cycle, the switching transistors in the inverter are controlled using the third current threshold and the fourth current threshold.

[0075] Wherein, the first current threshold is less than the second current threshold, and the first switching cycle is earlier than the second switching cycle.

[0076] In this embodiment of the invention, during the first switching cycle, the duration of current change is determined based on the times when the inductor current in the inverter equals a first current threshold and the times when the inductor current equals a second current threshold. Based on the duration of current change, the first current threshold, and the second current threshold, the rate of change of current is determined. If the rate of change of current is greater than a preset threshold, both the first and second current thresholds are reduced. During the second switching cycle, the reduced two current thresholds are used to control the corresponding switching transistors in the inverter. The first current threshold is less than the second current threshold, and the first switching cycle is earlier than the second switching cycle. A current rate of change greater than the preset threshold indicates a rapid current increase. To protect the switching transistors and the inverter, the current thresholds are reduced, and the reduced two current thresholds are used to control the switching transistors in the inverter during the next switching cycle. Compared to using a smaller current threshold to control the switching transistors when the current is rising rapidly, this reduces the risk of damage to the switching transistors, thereby reducing the risk of damage to the inverter and improving its reliability.

[0077] The inverter control method disclosed in this invention is applicable to any inverter with two or more different current thresholds, such as the type I three-level inverter mentioned above, or the type T three-level inverter.

[0078] In specific implementation, a first current threshold and a second current threshold can be preset first. In order to ensure that the switching transistor is not damaged, the maximum allowable inductance current of the switching transistor can be determined under short-circuit conditions. This current can be used as the second current threshold, and then a current less than the second current threshold can be selected as the first current threshold. The difference between the second current threshold and the first current threshold can be determined according to the actual situation. This embodiment of the invention does not impose any limitations.

[0079] In the first switching cycle, after the switching transistor in the inverter turns on, the inductor current rises rapidly. The duration for which the inductor current equals the first current threshold and the duration for which the inductor current equals the second current threshold is taken as the current change duration. Specifically, the current change duration can be determined in the following way:

[0080] Method 1: In the first switching cycle, when the inductor current equals the first current threshold, the control system software starts timing, and when the inductor current equals the second current threshold, the control system software stops timing, and the timing duration is used as the current change duration.

[0081] For example, such as Figure 4 As shown, the timer starts counting at time t1 and stops counting at time t2, and the timing duration is taken as the duration of current change.

[0082] Method 2: In the first switching cycle, determine the first moment when the inductor current in the inverter is equal to the first current threshold, and the second moment when the inductor current is equal to the second current threshold. Use the time between the second moment and the first moment as the current change duration.

[0083] For example, such as Figure 4 As shown, at time t1, the inductor current is equal to the first current threshold, and at time t2, the inductor current is equal to the second current threshold. The duration between time t1 and time t2 is the duration of current change.

[0084] After obtaining the duration of current change, the rate of change of current is determined based on the duration of current change, the first current threshold, and the second current threshold.

[0085] Specifically, the difference between the first current threshold and the second current threshold is divided by the current change time to obtain the current change rate.

[0086] For example, such as Figure 4 As shown, the rate of change of current is equal to (i2-i1) / (t2-t1).

[0087] In this embodiment of the invention, the current change rate is used to characterize the current rise speed. The calculated current change rate is compared with a preset threshold. If the current change rate is greater than the preset threshold, it indicates that the current rise speed is fast, and a short circuit has been determined in the inverter. After determining that a short circuit has occurred in the inverter, in order to better protect the switching transistors, both the first and second current thresholds are reduced to obtain a third and a fourth current threshold.

[0088] In practical implementation, the preset threshold can be determined by first identifying the current rise rate under normal operating conditions and the current rise rate under short-circuit conditions, and then selecting a value from those values ​​that are higher than the current rise rate under normal operating conditions but lower than the current rise rate under short-circuit conditions as the preset threshold. The current rise rate under normal operating conditions and the current rise rate under short-circuit conditions can be determined based on actual measurements.

[0089] If the operating condition is determined to be a short-circuit condition, it can be determined using the following formula:

[0090]

[0091] Among them, U dc U is the DC bus voltage. out Let t2 be the output voltage, L be the inductance of the inductor, i2 be the second current threshold, i1 be the first current threshold, t2 be the moment when the inductor current equals the second current threshold, and t1 be the moment when the inductor current equals the first current threshold.

[0092] U dcL, i2, i1, t2, and t1 are all known quantities. U can be calculated using the above formula. out If the calculated U out If the value approaches zero, it indicates that the inverter has short-circuited.

[0093] In the second switching cycle, which is the next switching cycle after the inverter short circuit, the third and fourth current thresholds are used to control the switching transistors in the inverter.

[0094] Specifically, in the second switching cycle, when the inductor current equals the third current threshold, the first switch corresponding to the first current threshold is turned off; when the inductor current equals the fourth current threshold, the second switch corresponding to the second current threshold is turned off, and the fourth current threshold is greater than the third current threshold.

[0095] by Figure 1 Taking the inverter in the example, after a short circuit is detected in the inverter, in the next switching cycle after the short circuit occurs, when the inductor current is equal to the third current threshold, the external transistors Q1 and Q4 are turned off, and when the inductor current is equal to the fourth current threshold, the internal transistors Q2 and Q3 are turned off.

[0096] This invention reduces two current thresholds and uses these reduced current thresholds to control the switching transistors in the inverter. This reduces the risk of damage to the switching transistors due to excessively rapid current rise during short-circuit conditions, thereby better protecting the inverter and improving its reliability.

[0097] If the rate of change of current is less than or equal to the preset threshold, it indicates that the inverter has not experienced a short circuit, and the first current threshold and the second current threshold are used to control the switching transistors in the inverter.

[0098] As one embodiment, the second current threshold may be less than the maximum inductance current allowed by the switching transistor under short-circuit conditions, while the first current threshold may also be relatively small.

[0099] For example, if the maximum allowable inductance current of the switching transistor under short-circuit conditions is 100A, then 100A can be used as the second current threshold and 80A as the first current threshold. Alternatively, a current value less than 100A can be used as the second current threshold, such as 90A as the second current threshold and 70A as the first current threshold.

[0100] By using two smaller current thresholds, short-circuit conditions can be detected before the current reaches the short-circuit current, thus providing better protection for the switching transistors and equipment.

[0101] It should be noted that in this embodiment of the invention, the switch corresponding to the first current threshold is the switch that is turned off first, such as the outer switch in a type I three-level inverter, and the switch corresponding to the second current threshold is the switch that is turned off later, such as the inner switch in a type I three-level inverter. For a two-level inverter, although there is actually only one current limiting point, that is, one current threshold, the current rise rate can be calculated by adding an additional reference current limiting point (current threshold) to determine whether a short circuit has occurred.

[0102] For a two-level inverter, since there is no distinction between internal and external transistors, it only includes one current threshold, such as the seventh current threshold. If a short circuit is detected, the duration of the current change is determined based on the times when the inductor current in the two-level inverter equals the preset current threshold and the times when the inductor current equals the seventh current threshold. The rate of change of the current is then determined based on this duration, the preset current threshold, and the seventh current threshold. If the rate of change of the current is greater than the preset threshold, both the preset and seventh current thresholds are reduced. In the next switching cycle, the current threshold adjusted by reducing the seventh current threshold is used to control the switching transistors in the two-level inverter, where the preset current threshold is less than the seventh current threshold. The above steps are repeated in other switching cycles.

[0103] The concept of the control method for two-level inverters is the same as that for three-level inverters. The specific control can be referred to the control method for three-level inverters described above. Repeated points will not be repeated.

[0104] The switching transistors in the embodiments of the present invention can be semiconductor switching devices such as IGBTs, MOSFETs, SiC MOSFETs, and gallium nitride transistors.

[0105] As one embodiment, in the first switching cycle, when the inductor current is equal to a first current threshold, the first switch corresponding to the first current threshold is turned off, and when the inductor current is equal to a second current threshold, the second switch corresponding to the second current threshold is turned off.

[0106] by Figure 1 Taking the Type I three-level inverter shown as an example, in the first switching cycle, when the inductor current is equal to the first current threshold, the external transistors Q1 and Q4 are turned off, and when the inductor current is equal to the second current threshold, the internal transistors Q2 and Q3 are turned off.

[0107] In this embodiment of the invention, after the first switch is turned off, the second switch is controlled to turn off, which can protect both the first and second switches. It should be noted that the first switch here corresponds to the external switch of the three-level inverter, and the second switch corresponds to the internal switch of the three-level inverter.

[0108] The first switching cycle, which is the switching cycle in which the inverter short circuit is determined, means that after the inverter short circuit is determined in the first switching cycle, the corresponding switching transistors in the inverter are controlled using the first current threshold and the second current threshold, and the first current threshold and the second current threshold are adjusted to decrease. In the next switching cycle, that is, the second switching cycle, the reduced current threshold is used to control the switching transistors in the inverter.

[0109] In the second switching cycle, after controlling the switching transistors in the inverter using the third and fourth current thresholds, in the third switching cycle, if the rate of change of current is less than or equal to a preset threshold, the third current threshold is adjusted to the first current threshold, and the fourth current threshold is adjusted to the second current threshold. In the fourth switching cycle, the first and second current thresholds are used to control the switching transistors in the inverter. The second switching cycle is earlier than the third switching cycle, and the third switching cycle is earlier than the fourth switching cycle.

[0110] Meanwhile, in the third switching cycle, when the inductor current equals the third current threshold, the first switch corresponding to the first current threshold is turned off, and when the inductor current equals the fourth current threshold, the second switch corresponding to the second current threshold is turned off.

[0111] In this embodiment of the invention, during the second switching cycle, when the inductor current equals the third current threshold, the switch corresponding to the first current threshold is turned off; when the inductor current equals the fourth current threshold, the switch corresponding to the second current threshold is turned off. In the next cycle, the third switching cycle, the third and fourth current thresholds are used to control the switches in the inverter. That is, when the inductor current equals the third current threshold, the switch corresponding to the first current threshold is turned off; when the inductor current equals the fourth current threshold, the switch corresponding to the second current threshold is turned off. Simultaneously, during the third switching cycle, at the third moment when the inductor current equals the third current threshold, the inductor current is determined to equal the fourth current threshold. At the fourth moment, the duration between the third and fourth moments is taken as the second current change duration. The difference between the fourth current threshold and the third current threshold is calculated, and the quotient of the difference and the second current change duration is taken as the second current change rate. The second current change rate is compared with a preset threshold. If it is greater than the preset threshold, the third and fourth current thresholds are used to control the switching transistor in the next switching cycle. If it is less than or equal to the preset threshold, it indicates that there is no short circuit. The third current threshold is increased to obtain the fifth current threshold, and the fourth current threshold is increased to obtain the sixth current threshold. In the next switching cycle after the third switching cycle, i.e., the fourth switching cycle, the fifth and sixth current thresholds are used to control the switching transistor.

[0112] It should be noted that, in the embodiments of the present invention, the fifth current threshold may be equal to, less than, or greater than the first current threshold, and the sixth current threshold may be equal to, less than, or greater than the second current threshold.

[0113] For example, some products have higher reliability requirements but lower output capability requirements. If a short circuit occurs and then disappears, for safety reasons, the current will not return to the original threshold values ​​(i.e., the first and second current thresholds) before shutdown for maintenance. If the current is not precisely restored to the first and second current thresholds, but slightly higher or lower, a essentially equivalent effect can be achieved.

[0114] As one embodiment, in the third switching cycle, if the rate of change of current is less than or equal to a preset threshold, the third current threshold is reduced to obtain a fifth current threshold, and the fourth current threshold is reduced to obtain a sixth current threshold. After a preset time, the third current threshold is adjusted to the fifth current threshold, and after a preset time, the fourth current threshold is adjusted to the sixth current threshold.

[0115] When a short circuit occurs, it may not be due to direct contact, but rather insufficient insulation distance leading to arcing and causing intermittent short circuits. Delaying the recovery current threshold by a preset time can prevent frequent adjustments to the current threshold when short circuits recur, thus avoiding the inability to provide continuous and effective protection for the device.

[0116] Because the software processes very quickly, it can complete the calculation, judgment and adjustment within one switching cycle. Therefore, when a short circuit occurs, the switching transistor will be blocked according to the original current threshold (first current threshold and second current threshold) in the first switching cycle (the switching cycle in which the short circuit occurs). In subsequent switching cycles (the second switching cycle), it will be blocked according to the reduced current threshold (third current threshold and fourth current threshold), which greatly reduces the risk of damage to the switching transistor.

[0117] If the short-circuit condition disappears and the inductor current rises at a rate lower than or equal to the preset threshold, the software can restore the original current threshold immediately or after a certain period of time (from the third current threshold to the first current threshold, or from the fourth current threshold to the second current threshold) to ensure the maximum output capacity of the device.

[0118] It should be noted that the first switching cycle in the embodiments of the present invention does not refer to the first switching cycle. Similarly, the second, third and fourth switching cycles are not related to which switching cycle. The embodiments of the present invention only limit the first switching cycle to be earlier than the second switching cycle, the second switching cycle to be earlier than the third switching cycle, and the third switching cycle to be earlier than the fourth switching cycle.

[0119] For example, if a short circuit occurs in the first switching cycle and the short circuit lasts for multiple switching cycles, the second switching cycle is the next switching cycle after the first switching cycle. At the beginning of the second switching cycle, the current change rate must be judged in each switching cycle. If the current change rate is less than a preset threshold, the current threshold will be increased in the next cycle or after a delay of several cycles (a preset delay time). The switching cycle in which the current threshold is increased is the third switching cycle, and the next switching cycle after the third switching cycle is the fourth switching cycle.

[0120] like Figure 5 The diagram shown is a flowchart illustrating a control system for dynamically adjusting the current threshold according to an embodiment of the present invention.

[0121] based on Figure 1 The Type I three-level inverter shown first receives an overcurrent signal from either the inner or outer transistor. When the inductor current exceeds the outer transistor's current threshold, a timer starts counting; when the inductor current exceeds the inner transistor's current threshold, the timer stops counting. Based on the timer data, the rate of change of the inductor current is calculated. If the rate of change is greater than a preset threshold, both the first and second current thresholds are decreased to obtain a third and a fourth current threshold. These third and fourth current thresholds are used to control the switching transistor. If the rate of change is less than or equal to a preset threshold when using the third and fourth current thresholds, both the third and fourth current thresholds are increased to obtain a fifth and a sixth current threshold. These fifth and sixth current thresholds are used to control the switching transistor. If the rate of change is still greater than the preset threshold, the third and fourth current thresholds are continued to be used. Similarly, if the rate of change is less than a preset threshold when using the first and second current thresholds to control the switching transistor, these first and second current thresholds are continued to be used. The timer is reset when the inductor current is lower than the internal tube current threshold.

[0122] It should be noted that in this embodiment of the invention, the outer tube current threshold is the first current threshold, and the inner tube current threshold is the second current threshold.

[0123] like Figure 6 The diagram shown is a schematic overall flow chart of an inverter control method provided in an embodiment of the present invention.

[0124] S601. In the first switching cycle, determine the duration of the first current change based on the time when the inductor current in the inverter is equal to the first current threshold and the time when the inductor current is equal to the second current threshold.

[0125] It should be noted that the first current threshold and the second current threshold are preset and are reference values ​​for the current limiting point before adjustment.

[0126] S602. Determine the first current change rate based on the current change duration, the first current threshold, and the second current threshold.

[0127] S603. Determine whether the rate of change of the first current is greater than the preset threshold. If yes, execute S604; otherwise, execute S609.

[0128] S604. The first current threshold is reduced to obtain the third current threshold, and the second current threshold is reduced to obtain the fourth current threshold.

[0129] The third and fourth current thresholds are the adjusted current limiting point reference values. The specific adjustment method can be to reduce the first current threshold to a first preset value and reduce the second current threshold to a second preset value. The first preset value and the second preset value can be the same or different.

[0130] Meanwhile, during the first switching cycle, when the inductor current equals the first current threshold, the outer transistors Q1 and Q4 are turned off, and when the inductor current equals the second current threshold, the inner transistors Q2 and Q3 are turned off.

[0131] S605. In the second switching cycle, when the inductor current equals the third current threshold, control the outer transistors Q1 and Q4 to turn off, and when the inductor current equals the fourth current threshold, control the inner transistors Q2 and Q3 to turn off. At the same time, calculate the second current change rate.

[0132] The method for calculating the second current change rate is the same as described above, and will not be repeated here.

[0133] S606. Determine whether the rate of change of the second current is greater than the preset threshold. If yes, execute S610; otherwise, execute S607.

[0134] S607. In the third switching cycle, when the inductor current is equal to the third current threshold, control the external transistors Q1 and Q4 to turn off. When the inductor current is equal to the fourth current threshold, control the internal transistors Q2 and Q3 to turn off. At the same time, increase the third current threshold to obtain the fifth current threshold, and increase the fourth current threshold to obtain the sixth current threshold.

[0135] It should be noted that in S607, the third current threshold can also be adjusted to the first current threshold, and the fourth current threshold can be adjusted to the second current threshold. In specific implementation, this can be determined according to the actual situation.

[0136] S608. In the fourth switching cycle, when the inductor current equals the fifth current threshold, control the external transistors Q1 and Q4 to turn off, and when the inductor current equals the sixth current threshold, control the internal transistors Q2 and Q3 to turn off.

[0137] S609. In the second switching cycle, when the inductor current is equal to the first current threshold, control the outer transistors Q1 and Q4 to turn off, and when the inductor current is equal to the second current threshold, control the inner transistors Q2 and Q3 to turn off. At the same time, calculate the second current change rate and execute S606.

[0138] S610. In the third switching cycle, when the inductor current is equal to the third current threshold, control the external transistors Q1 and Q4 to turn off. When the inductor current is equal to the fourth current threshold, control the internal transistors Q2 and Q3 to turn off. At the same time, the third current threshold is reduced to obtain the seventh current threshold, and the fourth current threshold is reduced to obtain the eighth current threshold.

[0139] S611. In the fourth switching cycle, when the inductor current equals the seventh current threshold, control the external transistors Q1 and Q4 to turn off, and when the inductor current equals the eighth current threshold, control the internal transistors Q2 and Q3 to turn off.

[0140] Based on the same concept, this embodiment of the invention also provides an inverter control device. Since this device is the same as the device in the method of this embodiment of the invention, and the principle of the device in solving the problem is similar to that of the method, the implementation of the device can refer to the implementation of the method, and the repeated parts will not be described again.

[0141] like Figure 7 The diagram shown is a structural schematic of an inverter control device provided in an embodiment of the present invention. The device includes:

[0142] The first determining module 701 is used to determine the current change duration in the first switching cycle based on the time when the inductor current in the inverter is equal to a first current threshold and the time when the inductor current is equal to a second current threshold.

[0143] The second determining module 702 is used to determine the current change rate based on the current change duration, the first current threshold, and the second current threshold.

[0144] The adjustment module 703 is used to reduce the first current threshold to obtain a third current threshold and reduce the second current threshold to obtain a fourth current threshold if the rate of change of the current is greater than a preset threshold.

[0145] Control module 704 is used to control the switching transistors in the inverter using the third current threshold and the fourth current threshold during the second switching cycle.

[0146] Wherein, the first current threshold is less than the second current threshold, and the first switching cycle is earlier than the second switching cycle.

[0147] Optionally, in the first switching cycle, the control module 704 is further configured to:

[0148] When the inductor current is equal to the first current threshold, the first switch corresponding to the first current threshold is turned off.

[0149] When the inductor current is equal to the second current threshold, the second switch corresponding to the second current threshold is turned off.

[0150] Optionally, the control module 704 is specifically used for:

[0151] When the inductor current is equal to the third current threshold, the first switch corresponding to the first current threshold is turned off.

[0152] When the inductor current is equal to the fourth current threshold, the second switch corresponding to the second current threshold is turned off.

[0153] Optionally, in the second switching cycle, after controlling the switching transistors in the inverter using the third current threshold and the fourth current threshold, the adjustment module 703 is further configured to:

[0154] In the third switching cycle, if the rate of change of current is less than or equal to the preset threshold, the third current threshold is increased to obtain the fifth current threshold, and the fourth current threshold is increased to obtain the sixth current threshold.

[0155] In the fourth switching cycle, the switching transistors in the inverter are controlled using the fifth current threshold and the sixth current threshold;

[0156] Wherein, the second switching cycle is earlier than the third switching cycle, the third switching cycle is earlier than the fourth switching cycle, and the fifth current threshold is less than the sixth current threshold.

[0157] Optionally, the adjustment module 703 is specifically used for:

[0158] In the third switching cycle, if the rate of change of current is less than or equal to the preset threshold, the third current threshold is increased after a preset time to obtain the fifth current threshold, and the fourth current threshold is increased after the preset time to obtain the sixth current threshold.

[0159] Optionally, during the third switching cycle, the control module 704 is further configured to:

[0160] When the inductor current is equal to the third current threshold, the first switch corresponding to the first current threshold is turned off.

[0161] When the inductor current is equal to the fourth current threshold, the second switch corresponding to the second current threshold is turned off.

[0162] Optionally, the second current threshold is less than the inductor current of the inverter when the inverter is short-circuited.

[0163] Based on the same concept, this embodiment of the invention also provides an inverter control device. Since the inverter control device is the same device in the method of this embodiment of the invention, and the principle of the device in solving the problem is similar to that of the method, the implementation of the device can refer to the implementation of the method, and the repeated parts will not be described again.

[0164] The following reference Figure 8 To describe an inverter control device 80 according to this embodiment of the invention. Figure 8 The inverter control device 80 shown is merely an example and should not impose any limitations on the functionality and scope of use of the embodiments of the present invention.

[0165] like Figure 8 As shown, the inverter control device 80 can be represented in the form of a general-purpose computing device, such as a terminal device. The components of the inverter control device 80 may include, but are not limited to: at least one processor 81, at least one memory 82 storing instructions executable by the processor 81, and a bus 83 connecting different system components (including the memory 82 and the processor 81), wherein the processor 81 is a processor of a smart device.

[0166] Processor 81 performs the following steps by executing executable instructions:

[0167] In the first switching cycle, the duration of current change is determined based on the time when the inductor current in the inverter is equal to the first current threshold and the time when the inductor current is equal to the second current threshold.

[0168] The rate of change of current is determined based on the duration of the current change, the first current threshold, and the second current threshold.

[0169] If the rate of change of current is greater than a preset threshold, then the first current threshold is reduced to obtain a third current threshold, and the second current threshold is reduced to obtain a fourth current threshold.

[0170] In the second switching cycle, the switching transistors in the inverter are controlled using the third current threshold and the fourth current threshold;

[0171] Wherein, the first current threshold is less than the second current threshold, and the first switching cycle is earlier than the second switching cycle.

[0172] In one embodiment, during the first switching cycle, the processor 81 is further configured to:

[0173] When the inductor current is equal to the first current threshold, the first switch corresponding to the first current threshold is turned off.

[0174] When the inductor current is equal to the second current threshold, the second switch corresponding to the second current threshold is turned off.

[0175] In one embodiment, during the second switching cycle, the processor 81 is specifically configured to:

[0176] When the inductor current is equal to the third current threshold, the first switch corresponding to the first current threshold is turned off.

[0177] When the inductor current is equal to the fourth current threshold, the second switch corresponding to the second current threshold is turned off.

[0178] In one embodiment, after controlling the switching transistors in the inverter using the third current threshold and the fourth current threshold during the second switching cycle, the processor 81 is further configured to:

[0179] In the third switching cycle, if the rate of change of current is less than or equal to the preset threshold, the third current threshold is increased to obtain the fifth current threshold, and the fourth current threshold is increased to obtain the sixth current threshold.

[0180] In the fourth switching cycle, the switching transistors in the inverter are controlled using the fifth current threshold and the sixth current threshold;

[0181] Wherein, the second switching cycle is earlier than the third switching cycle, the third switching cycle is earlier than the fourth switching cycle, and the fifth current threshold is less than the sixth current threshold.

[0182] In one embodiment, processor 81 is specifically used for:

[0183] In the third switching cycle, if the rate of change of current is less than or equal to the preset threshold, the third current threshold is increased after a preset time to obtain the fifth current threshold, and the fourth current threshold is increased after the preset time to obtain the sixth current threshold.

[0184] In one embodiment, during the third switching cycle, the processor 81 is further configured to:

[0185] When the inductor current is equal to the third current threshold, the first switch corresponding to the first current threshold is turned off.

[0186] When the inductor current is equal to the fourth current threshold, the second switch corresponding to the second current threshold is turned off.

[0187] In one embodiment, the second current threshold is less than the inductor current of the inverter when the inverter is short-circuited.

[0188] Bus 83 represents one or more of several bus structures, including a memory bus or memory controller, peripheral bus, processor, or local bus using any of the various bus structures.

[0189] The memory 82 may include a readable medium in the form of volatile memory, such as random access memory (RAM) 821 and / or cache memory 822, and may further include read-only memory (ROM) 823.

[0190] The memory 82 may also include a program / utility 825 having a set (at least one) of program modules 824, including but not limited to: an operating system, one or more application programs, other program modules, and program data, each or some combination of these examples may include an implementation of a network environment.

[0191] The inverter control device 80 can also communicate with one or more external devices 84 (e.g., keyboard, pointing device, etc.), one or more devices that enable users to interact with the inverter control device 80, and / or any device that enables the inverter control device 80 to communicate with one or more other computing devices (e.g., router, modem, etc.). This communication can be performed via input / output (I / O) interface 85. Furthermore, the inverter control device 80 can also communicate with one or more networks (e.g., local area network (LAN), wide area network (WAN), and / or public networks, such as the Internet) via network adapter 86. As shown, network adapter 86 communicates with other modules of the inverter control device 80 via bus 83. It should be understood that, although not shown in the figures, other hardware and / or software modules can be used in conjunction with the inverter control device 80, including but not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data backup storage systems.

[0192] It should be noted that the processor in this embodiment of the invention includes not only processors such as CPUs, MCUs, and DSPs, but also programmable logic devices such as CPLDs and FPGAs. The CPU, MCU, and DSP processors, along with the programmable logic devices, jointly perform the above method. For example, the CPU, MCU, and DSP processors are responsible for adjusting the threshold and controlling the switching transistors, while the programmable logic devices are responsible for receiving overcurrent signals from peripheral circuits and calculating and determining the rate of change of current. The programmable logic devices can be located between the CPU, MCU, and DSP processors and the peripherals.

[0193] It should be noted that the division of labor between processors such as CPU, MCU, and DSP and programmable logic devices is not limited to the division of labor described above. Other divisions of labor that can implement the method of the present invention are also applicable to the embodiments of the present invention. Alternatively, programmable logic devices can be used without the need for programmable logic devices, and any method disclosed in the above embodiments can be implemented.

[0194] In some possible implementations, embodiments of the present invention also provide a computer storage medium storing computer instructions that, when executed on a computer, cause the computer to perform the steps of the inverter control method as described in any of the above descriptions.

[0195] In some possible implementations, various aspects of the present invention can also be implemented as a program product comprising program code. When the program product is run on a terminal device, the program code causes the terminal device to execute the steps of the modules in the inverter control apparatus according to various exemplary embodiments of the present disclosure as described in the "Exemplary Methods" section above. For example, the terminal may be used to determine the current change duration in a first switching cycle based on the time when the inductor current in the inverter equals a first current threshold and the time when the inductor current equals a second current threshold; determine the current change rate based on the current change duration, the first current threshold, and the second current threshold; if the current change rate is greater than a preset threshold, reduce the first current threshold to obtain a third current threshold and reduce the second current threshold to obtain a fourth current threshold; and in a second switching cycle, control the switching transistors in the inverter using the third current threshold and the fourth current threshold; wherein the first current threshold is less than the second current threshold, and the first switching cycle is earlier than the second switching cycle.

[0196] The program product may employ any combination of one or more readable media. A readable medium may be a readable signal medium or a readable storage medium. A readable storage medium may be, for example—but not limited to—an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples (a non-exhaustive list) of readable storage media include: electrical connections having one or more wires, portable disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0197] like Figure 9 As shown, a program product 90 for inverter control according to an embodiment of the present invention is described, which may employ a portable compact disc read-only memory (CD-ROM) and include program code, and may run on a terminal device, such as a personal computer. However, the program product of the present invention is not limited thereto. In this document, the readable storage medium may be any tangible medium containing or storing a program that may be used by or in conjunction with an instruction execution system, apparatus, or device.

[0198] A readable signal medium may include a data signal propagated in baseband or as part of a carrier wave, carrying readable program code. This propagated data signal may take many forms, including—but not limited to—electromagnetic signals, optical signals, or any suitable combination thereof. A readable signal medium may also be any readable medium other than a readable storage medium, capable of sending, propagating, or transmitting a program for use by or in conjunction with an instruction execution system, apparatus, or device.

[0199] The program code contained on the readable medium may be transmitted using any suitable medium, including—but not limited to—wireless, wired, optical fiber, RF, or any suitable combination thereof.

[0200] Program code for performing the operations of this invention can be written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Java and C++, and conventional procedural programming languages ​​such as C or similar languages. The program code can execute entirely on the user's computing device, partially on the user's device, as a standalone software package, partially on the user's computing device and partially on a remote computing device, or entirely on a remote computing device or server. In cases involving remote computing devices, the remote computing device can be connected to the user's computing device via any type of network—including a local area network (LAN) or a wide area network (WAN)—or can be connected to an external computing device (e.g., via the Internet using an Internet service provider).

[0201] It should be noted that although several modules or sub-modules of the system have been mentioned in the detailed description above, this division is merely exemplary and not mandatory. In fact, according to embodiments of the present invention, the features and functions of two or more modules described above can be embodied in one module. Conversely, the features and functions of one module described above can be further divided and embodied by multiple modules.

[0202] The present application has been described above with reference to block diagrams and / or flowcharts illustrating methods, apparatus (systems), and / or computer program products according to embodiments of the present application. It should be understood that a block of a block diagram and / or flowchart, as well as combinations of blocks of block diagrams and / or flowcharts, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, and / or other programmable data processing means to produce a machine, such that the instructions, executable via the computer processor and / or other programmable data processing means, create methods for implementing the functions / actions specified in the blocks of the block diagrams and / or flowcharts.

[0203] Accordingly, this application can also be implemented using hardware and / or software (including firmware, resident software, microcode, etc.). Furthermore, this application can take the form of a computer program product on a computer-usable or computer-readable storage medium, having computer-usable or computer-readable program code implemented in the medium for use by or in conjunction with an instruction execution system. In the context of this application, a computer-usable or computer-readable medium can be any medium that can contain, store, communicate, transmit, or deliver a program for use by or in conjunction with an instruction execution system, apparatus, or device.

[0204] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. An inverter control method, characterized in that, The method includes: In the first switching cycle, the duration of current change is determined based on the moment when the inductor current in the inverter equals the first current threshold and the moment when the inductor current equals the second current threshold. The rate of change of current is determined based on the duration of the current change, the first current threshold, and the second current threshold. If the rate of change of current is greater than a preset threshold, then the first current threshold is reduced to obtain a third current threshold, and the second current threshold is reduced to obtain a fourth current threshold. In the second switching cycle, the switching transistors in the inverter are controlled using the third current threshold and the fourth current threshold; Wherein, the first current threshold is less than the second current threshold, and the first switching cycle is earlier than the second switching cycle.

2. The method as described in claim 1, characterized in that, In the first switching cycle, the method further includes: When the inductor current is equal to the first current threshold, the first switch corresponding to the first current threshold is turned off. When the inductor current is equal to the second current threshold, the second switch corresponding to the second current threshold is turned off.

3. The method as described in claim 1, characterized in that, During the second switching cycle, the switching transistors in the inverter are controlled using the third current threshold and the fourth current threshold, including: When the inductor current is equal to the third current threshold, the first switch corresponding to the first current threshold is turned off. When the inductor current is equal to the fourth current threshold, the second switch corresponding to the second current threshold is turned off.

4. The method as described in claim 1, characterized in that, In the second switching cycle, after controlling the switching transistors in the inverter using the third current threshold and the fourth current threshold, the method further includes: In the third switching cycle, if the rate of change of current is less than or equal to the preset threshold, the third current threshold is increased to obtain the fifth current threshold, and the fourth current threshold is increased to obtain the sixth current threshold. In the fourth switching cycle, the switching transistors in the inverter are controlled using the fifth current threshold and the sixth current threshold; Wherein, the second switching cycle is earlier than the third switching cycle, the third switching cycle is earlier than the fourth switching cycle, and the fifth current threshold is less than the sixth current threshold.

5. The method as described in claim 4, characterized in that, In the third switching cycle, if the rate of change of current is less than or equal to the preset threshold, the third current threshold is increased to obtain a fifth current threshold, and the fourth current threshold is increased to obtain a sixth current threshold, including: In the third switching cycle, if the current change rate is less than or equal to the preset threshold, the third current threshold is increased after a preset time to obtain the fifth current threshold, and the fourth current threshold is increased after the preset time to obtain the sixth current threshold.

6. The method as described in claim 4, characterized in that, In the third switching cycle, the method further includes: When the inductor current is equal to the third current threshold, the first switch corresponding to the first current threshold is turned off. When the inductor current is equal to the fourth current threshold, the second switch corresponding to the second current threshold is turned off.

7. The method according to any one of claims 1 to 6, characterized in that, The second current threshold is less than the inductor current of the inverter when the inverter is short-circuited.

8. An inverter control device, characterized in that, The device includes: The first determining module is used to determine the duration of current change in the first switching cycle based on the time when the inductor current in the inverter is equal to a first current threshold and the time when the inductor current is equal to a second current threshold. The second determining module is used to determine the rate of change of current based on the duration of the current change, the first current threshold, and the second current threshold. An adjustment module is used to reduce the first current threshold to obtain a third current threshold and reduce the second current threshold to obtain a fourth current threshold if the rate of change of the current is greater than a preset threshold. A control module is configured to control the switching transistors in the inverter using the third current threshold and the fourth current threshold during a second switching cycle. Wherein, the first current threshold is less than the second current threshold, and the first switching cycle is earlier than the second switching cycle.

9. The apparatus as claimed in claim 8, characterized in that, During the first switching cycle, the control module is further configured to: When the inductor current is equal to the first current threshold, the first switch corresponding to the first current threshold is turned off. When the inductor current is equal to the second current threshold, the second switch corresponding to the second current threshold is turned off.

10. The apparatus as claimed in claim 8, characterized in that, The control module is specifically used for: When the inductor current is equal to the third current threshold, the first switch corresponding to the first current threshold is turned off. When the inductor current is equal to the fourth current threshold, the second switch corresponding to the second current threshold is turned off.

11. The apparatus as claimed in claim 8, characterized in that, In the second switching cycle, after controlling the switching transistors in the inverter using the third current threshold and the fourth current threshold, the adjustment module is further configured to: In the third switching cycle, if the rate of change of current is less than or equal to the preset threshold, the third current threshold is increased to obtain the fifth current threshold, and the fourth current threshold is adjusted to obtain the sixth current threshold. In the fourth switching cycle, the switching transistors in the inverter are controlled using the fifth current threshold and the sixth current threshold; Wherein, the second switching cycle is earlier than the third switching cycle, the third switching cycle is earlier than the fourth switching cycle, and the fifth current threshold is less than the sixth current threshold.

12. The apparatus as claimed in claim 11, characterized in that, The adjustment module is specifically used for: In the third switching cycle, if the current change rate is less than or equal to the preset threshold, the third current threshold is increased after a preset time to obtain the fifth current threshold, and the fourth current threshold is increased after the preset time to obtain the sixth current threshold.

13. The apparatus as claimed in claim 11, characterized in that, In the third switching cycle, the control module is further configured to: When the inductor current is equal to the third current threshold, the first switch corresponding to the first current threshold is turned off. When the inductor current is equal to the fourth current threshold, the second switch corresponding to the second current threshold is turned off.

14. The apparatus as described in any one of claims 8 to 13, characterized in that, The second current threshold is less than the inductor current of the inverter when the inverter is short-circuited.

15. An inverter control device, characterized in that, The device includes a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps of the inverter control method according to any one of claims 1 to 7.

16. A computer storage medium, characterized in that, The computer storage medium stores computer instructions that, when executed on the computer, cause the computer to perform the steps of the inverter control method as described in any one of claims 1 to 7.

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