Narrow pulse control method and device of inverter

Abstract

The invention provides a narrow pulse control method and device for an inverter, and relates to the field of inverter control, and the method comprises the steps: obtaining a narrow pulse threshold upper limit and a narrow pulse threshold lower limit, and calculating a target compensation range; obtaining a three-phase modulation signal, and performing switch tube voltage drop compensation and residual compensation on the three-phase modulation signal to obtain an intermediate modulation signal; when the intermediate modulation signal is out of the target compensation range, outputting a predetermined target modulation signal; and when the intermediate modulation signal falls into the target compensation range, performing dead zone compensation on the intermediate modulation signal, calculating an equivalent modulation signal after a dead zone is inserted, performing modulation signal clamping processing according to the narrow pulse threshold upper limit, the narrow pulse threshold lower limit and the target compensation range, and removing the dead zone to output a target modulation signal. The problem of high safety risk caused by narrow pulse in the existing inverter control is solved.

Description

Technical Field

[0001] The present invention relates to the field of inverter control, and in particular to a narrow pulse control method and device for an inverter. Background Art

[0002] In modern power electronics, inverters are key devices for converting DC to AC power, and their performance plays a decisive role in numerous application systems. Inverter control technology is a key element in improving its performance, with narrow pulse control being closely linked to the inverter's operational stability, efficiency, and reliability.

[0003] During inverter operation, narrow pulses are a key factor affecting inverter performance. When using PWM (Pulse Width Modulation) modulation technology, narrow pulses can occur if the calculated pulse width is too small. For example, in space vector pulse width modulation (SVPWM), higher motor output efficiency, higher bus voltage utilization, and larger modulation ratios increase the likelihood of narrow pulses. Specifically, when near full modulation, the output voltage is high, the modulation wave amplitude is correspondingly large, and the resulting PWM signal duty cycle, when compared with the carrier wave, approaches 0 or 100%, making narrow pulses highly likely to occur.

[0004] Because the narrow pulse width is too short to fully turn on the power module, it can cause the power module to shut down again before it is fully turned on, generating a surge voltage significantly higher than normal. Repeated exposure to this surge voltage can cause the power module to experience large on- or off-voltage oscillations, significantly reducing the triggering reliability of the switching device and seriously affecting the normal operation of power electronic equipment. Summary of the Invention

[0005] In order to overcome the above technical defects, the purpose of the present invention is to provide a narrow pulse control method and device for an inverter, which is used to solve the problem of high safety risks caused by narrow pulses in existing inverter control.

[0006] The present invention discloses a narrow pulse control method for an inverter, comprising: Obtain the upper and lower limits of the narrow pulse threshold and calculate the target compensation range; Acquire a three-phase modulation signal, perform switch tube voltage drop compensation and residual compensation on the three-phase modulation signal, and obtain an intermediate modulation signal; When the intermediate modulation signal is outside the target compensation range, outputting a predetermined target modulation signal; When the intermediate modulation signal falls within the target compensation range, dead zone compensation is performed on the intermediate modulation signal, and an equivalent modulation signal after inserting the dead zone is calculated. Then, the modulation signal is clamped according to the narrow pulse threshold upper limit, the narrow pulse threshold lower limit, and the target compensation range, and the dead zone is removed to output the target modulation signal.

[0007] Preferably, performing dead zone compensation on the intermediate modulation signal and calculating the equivalent modulation signal after inserting the dead zone includes: Obtaining a dead zone compensation amount to perform dead zone compensation on the intermediate modulated signal; The current direction is determined according to the dead zone compensation amount, so that the intermediate modulation signal after the dead zone compensation is inserted into the dead zone according to the current direction to obtain an equivalent modulation signal.

[0008] Preferably, a first pulse width modulation wave having a periodic low level to high level to low level change and a second pulse width modulation ratio complementary to the first pulse width modulation wave are preset; wherein the high level duration is shortened when the first pulse width modulation wave is inserted into the dead zone, and the low level duration is prolonged when the second pulse width modulation wave is inserted into the dead zone; When the current direction is positive, the intermediate modulation signal after the dead zone compensation is inserted into the dead zone with reference to the first pulse width modulation wave to obtain an equivalent modulation signal; When the current direction is negative, the intermediate modulation signal after the dead zone compensation is inserted into the dead zone with reference to the second pulse width modulation wave to obtain an equivalent modulation signal.

[0009] Preferably, the clamping process of the modulation signal according to the narrow pulse threshold upper limit, the narrow pulse threshold lower limit, and the target compensation range includes: Obtaining an equivalent modulation signal; The target compensation range is formed by a compensation range lower limit and a compensation range upper limit; When the equivalent modulation signal exceeds the narrow pulse threshold upper limit, if it is between the narrow pulse threshold upper limit and the compensation range upper limit, the narrow pulse threshold upper limit is output; if it exceeds the compensation range upper limit, a predetermined first duty cycle is output; When the equivalent modulation signal does not reach the narrow pulse threshold lower limit, if it is between the narrow pulse threshold lower limit and the compensation range lower limit, then the narrow pulse threshold lower limit is output; if it does not reach the compensation range lower limit, then a predetermined second duty cycle is output; When the equivalent modulation signal is between the narrow pulse threshold upper limit and the narrow pulse threshold lower limit, the equivalent modulation signal is output.

[0010] Preferably, the residual compensation amount of the previous switching cycle is obtained to perform residual compensation on the three-phase modulation signal; After the target modulation signal is output, a residual compensation amount for a subsequent switching cycle is generated according to the target modulation signal and the three-phase modulation signal.

[0011] Preferably, after the target modulation signal is output, a dead zone is inserted based on the target modulation signal, and duty cycle correction is performed.

[0012] Preferably, the performing duty cycle correction includes: When the target modulation signal does not reach the narrow pulse lower limit after being inserted into the dead zone, a predetermined second duty cycle is output.

[0013] Preferably, when the intermediate modulated signal is outside the target compensation range: If the intermediate modulation signal exceeds an upper limit of a compensation range of a target compensation range, outputting a predetermined first duty cycle; If the intermediate modulation signal does not reach the compensation range lower limit of the target compensation range, a predetermined second duty cycle is output.

[0014] The present invention also provides a narrow pulse control device for an inverter, comprising: A control module is used to obtain an upper limit and a lower limit of a narrow pulse threshold and calculate a target compensation range; obtain a three-phase modulation signal, perform switch tube voltage drop compensation and residual compensation on the three-phase modulation signal, and obtain an intermediate modulation signal; when the intermediate modulation signal is outside the target compensation range, output a predetermined target modulation signal; when the intermediate modulation signal falls within the target compensation range, perform dead zone compensation on the intermediate modulation signal, calculate an equivalent modulation signal after inserting the dead zone, and then perform modulation signal clamping processing according to the upper limit and lower limit of the narrow pulse threshold and the target compensation range, and then remove the dead zone to output the target modulation signal.

[0015] Preferably, a dead zone insertion module and / or a duty cycle correction module are further included to connect the control module to the inverter drive circuit.

[0016] Compared with the existing technology, the above technical solution has the following beneficial effects: 1. Calculate the equivalent modulation signal after inserting the dead zone, then perform clamping processing based on the threshold, remove the inserted dead zone time margin, and output the target modulation signal. Consider the PWM change after the dead zone insertion and perform narrow pulse clamping. Reserve the dead zone time margin to suppress the occurrence of narrow pulses in the output PWM, solving the high safety risk problem caused by narrow pulses in existing inverter control. 2. The main clamping switch tube is selected according to the current direction, and the second duty cycle is adjusted at the same time to improve the control accuracy. The dead zone time will not be affected by the narrow pulse clamping of the PWM after the dead zone insertion, which effectively maintains the dead zone time length and improves the safety of use. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1This is a method flow chart of embodiments 1 and 2 of a narrow pulse control method and device for an inverter according to the present invention; Figure 2 Another flow chart of the methods of Embodiments 1 and 2 of the narrow pulse control method and device for an inverter according to the present invention; Figure 3 This is a flow chart using a 2μs narrow pulse as an example in the methods of Embodiments 1 and 2 of a narrow pulse control method and device for an inverter according to the present invention; Figure 4 A modulation wave reference diagram showing the equivalent modulation signal after inserting a dead zone in the methods of embodiments 1 and 2 of a narrow pulse control method and apparatus for an inverter according to the present invention; Figure 5 This is a module diagram of a second embodiment of a narrow pulse control method and device for an inverter according to the present invention.

[0018] Reference numerals: 5- narrow pulse control of the inverter; 51- control module; 52- dead zone insertion module; 53- duty cycle correction module. DETAILED DESCRIPTION

[0019] The advantages of the present invention are further described below with reference to the accompanying drawings and specific embodiments.

[0020] Exemplary embodiments will be described in detail herein, with examples illustrated in the accompanying drawings. In the following description, when referring to the drawings, identical numerals in different figures represent identical or similar elements, unless otherwise indicated. The embodiments described in the following exemplary embodiments are not intended to represent all possible embodiments consistent with the present disclosure. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present disclosure, as detailed in the appended claims.

[0021] The terms used in this disclosure are for the purpose of describing specific embodiments only and are not intended to limit the disclosure. As used in this disclosure and the appended claims, the singular forms "a," "an," "the," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that the term "and / or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.

[0022] It should be understood that although the terms first, second, third, etc. may be used in this disclosure to describe various information, such information should not be limited to these terms. These terms are only used to distinguish information of the same type from each other. For example, without departing from the scope of this disclosure, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the word "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining."

[0023] In the description of the present invention, unless otherwise specified and limited, it should be noted that the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a mechanical connection or an electrical connection, or it can be the internal communication between two components. It can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to the specific circumstances.

[0024] In the following description, the suffixes such as "module", "component" or "unit" used to represent elements are only used to facilitate the description of the present invention and have no specific meaning. Therefore, "module" and "component" can be used interchangeably.

[0025] Example: This embodiment discloses a narrow pulse control method for an inverter, which aims to suppress narrow pulses generated during the inverter control process to improve operational safety while providing higher control accuracy. Dead band refers to the control signal time interval set to avoid direct short circuit of power switching devices. In this embodiment, dead band is used to suppress narrow pulses. For details, see Figure 1 and Figure 2 , the control method includes: S10: Obtain the upper limit maxMPV and the lower limit minMPV of the narrow pulse threshold, and calculate the target compensation range; It can be understood that the control of the inverter during the inverter control process is achieved by adjusting the duty cycle, which determines the average value and waveform characteristics of the inverter output voltage. Therefore, in this embodiment, the control is achieved by adjusting the duty cycle. Therefore, the upper limit, lower limit, target compensation range, and modulation signal (such as three-phase modulation signal, intermediate modulation signal, equivalent modulation signal, target modulation signal light) in this embodiment are all expressed as duty cycle.

[0026] Specifically, maxMPV+minMPV=1; the upper and lower limits of the narrow pulse threshold are preset, which are related to the length of the narrow pulse generated. For example, in this embodiment, the maximum narrow pulse of 2 μs is limited (e.g. Figure 2 and Figure 3), the corresponding duty cycle is calculated to be 2μs / 100μs=0.02. Therefore, the portion exceeding 0.02 is likely to generate narrow pulses, which need to be suppressed in this embodiment.

[0027] To this end, a target compensation range is set, which can be calculated based on the narrow pulse threshold upper limit and the narrow pulse threshold lower limit, as shown in the following example: Wherein, minZero is the lower limit of the target compensation range, and maxOne is the upper limit of the target compensation range. The target compensation range is formed between minZero and maxOne. It is understood that other existing threshold setting methods can also be used to implement this method in different scenarios. In this embodiment, minZero = 0.01; maxOne = 0.99.

[0028] Based on this, it can be understood that the part exceeding 0.02 is not allowed, that is, duty cycles of <0.02 and >0.98 are not allowed, while 0.02~0.98 is feasible. This application defines the range of 0.01~0.99, and the part exceeding 0.02~0.98 in 0.01~0.99 is processed to suppress the generation of narrow pulses, while the others directly output the predetermined duty cycle as described below.

[0029] S20: Acquire a three-phase modulation signal, perform switch tube voltage drop compensation and residual compensation on the three-phase modulation signal, and obtain an intermediate modulation signal; Specifically, the aforementioned compensations all reduce or eliminate the impact of the voltage drop when the switch is turned on on the control process. The aforementioned voltage drop compensation for the switch can be provided by setting up an independent module to provide the voltage drop compensation amount. Specifically, the independent module can run existing common methods for calculating the voltage drop of the switch, such as a hardware compensation circuit or an onboard compensation algorithm. The aforementioned residual compensation is the voltage drop compensation formed during the previous switching cycle, and the corresponding residual compensation amount can be directly obtained. In this embodiment, the residual compensation amount of the previous switching cycle is obtained to perform residual compensation on the three-phase modulated signal. The aforementioned residual compensation amount can also be provided in an independent module. Optionally, in this embodiment, after outputting the target modulated signal, a residual compensation amount for the subsequent switching cycle is generated based on the target modulated signal and the three-phase modulated signal. That is, the residual compensation amount is generated by subtracting the output from the input of the control method of this application and stored for use in the subsequent switching cycle, without the need for additional control circuitry or control modules.

[0030] Assume three-phase modulation signal The switch tube voltage drop compensation is preset to ΔD; the residual compensation of the previous switching cycle is delx; then the intermediate modulation signal is ; in is the target modulation signal, and the calculated delx is used for the next switching cycle.

[0031] S30: When the intermediate modulation signal is outside the target compensation range, outputting a predetermined target modulation signal; Specifically, according to the above compensation Compared with the target compensation range formed between minZero and maxOne, when the intermediate modulation signal is outside the target compensation range: S30-1: if the intermediate modulation signal exceeds the upper limit of the compensation range of the target compensation range, output a predetermined first duty cycle, that is, if , the output is saturated value (First duty cycle). S30-2: If the intermediate modulation signal does not reach the lower limit of the compensation range of the target compensation range, output a predetermined second duty cycle, that is, if , the output is saturated value (Second duty cycle); In these two cases, directly output the first duty cycle / second duty cycle, directly output the saturation value, and then there is no need to consider the dead zone (dead time) insertion and dead zone compensation, as shown in the above example. or Directly output the aforementioned saturation value.

[0032] S40: When the intermediate modulated signal falls within the target compensation range, dead zone compensation is performed on the intermediate modulated signal, an equivalent modulated signal after the dead zone is inserted is calculated, and the modulated signal is clamped according to the narrow pulse threshold upper limit, the narrow pulse threshold lower limit, and the target compensation range, and the dead zone is removed to output the target modulated signal. As mentioned above, this embodiment specifically utilizes a dead zone insertion for clamping processing and then removes the dead zone to control the occurrence of narrow pulses. Specifically, the dead zone compensation of the intermediate modulation signal and the calculation of the equivalent modulation signal after the dead zone insertion include: S41: Obtaining a dead zone compensation amount to perform dead zone compensation on the intermediate modulated signal; Specifically, the dead zone compensation amount deadcomp can be obtained in advance and is related to the motor parameters and current. It can also be generated by establishing an independent module / model and can be obtained using existing general calculation methods. In this embodiment, it is used for feedforward compensation to achieve better subsequent clamping processing effects. The intermediate modulation signal after dead zone compensation is expressed as: .

[0033] S42: determining a current direction according to the dead zone compensation amount, so as to insert the intermediate modulation signal after the dead zone compensation into the dead zone according to the current direction to obtain an equivalent modulation signal.

[0034] As an illustration, different dead zone insertion operations based on different current directions result in different equivalent modulation waveforms. The positive and negative signs of the dead zone compensation (whether the dead zone compensation is positive or negative) are consistent with the positive and negative signs of the current, so the current direction can be derived based on this.

[0035] Specifically, a first pulse width modulation wave ( Figure 4 middle The waveform shown, without dead zone), is a second pulse width modulation ratio complementary to the first pulse width modulation wave ( Figure 4 middle The waveform shown, no dead zone is inserted), specifically the second pulse width modulation ratio as shown in the figure forms a periodic change from high level to low level to high level, wherein the second pulse width modulation ratio, wherein the high level duration is shortened when the dead zone is inserted into the first pulse width modulation wave ( Figure 4 middle The pink portion of the waveform shown For the inserted dead zone), the low level time is extended when the second PWM wave is inserted into the dead zone ( Figure 4 middle The pink portion of the waveform shown for inserted dead zone).

[0036] See Figure 4 As illustrated, in this embodiment, the applicant has found that when the current direction is positive, the waveform of the equivalent modulation signal obtained after inserting the dead zone is the same as Figure 4 middle The waveform shown is similar to that shown in the figure. When the current direction is negative, the waveform of the equivalent modulation signal obtained after inserting the dead zone is the same as that shown in the figure. Figure 4 middle The waveforms shown are similar, so when the current direction is positive, according to Figure 4 middle The first pulse width modulation wave is inserted into the dead zone (people in this field can generally understand that the pulse width modulation wave corresponds to the duty cycle of the upper tube, that is, the dead zone is inserted according to the duty cycle of the upper tube), and the Figure 4 middle The modulation wave shown in the figure, when the current direction is negative, according to Figure 4 middle The second pulse width modulation wave is inserted into the dead zone (people in this field can generally understand that the pulse width modulation wave corresponds to the duty cycle of the lower tube, that is, the dead zone is inserted according to the duty cycle of the lower tube), and the Figure 4 middle The modulated wave shown.

[0037] Therefore, in this embodiment, S42-1: when the current direction is positive, the intermediate modulation signal after the dead zone compensation is inserted into the dead zone with reference to the first pulse width modulation wave to obtain an equivalent modulation signal , The equivalent duty cycle of the dead time, so the waveform formed after the above tube duty cycle is inserted into the dead zone can be referred to Figure 4 middle S42-2: When the current direction is negative, the intermediate modulation signal after the dead zone compensation is inserted into the dead zone with reference to the second pulse width modulation wave to obtain an equivalent modulation signal ; Due to the symmetry of the narrow pulse clamping and in order to correspond to the first duty cycle, the equivalent modulation signal Therefore, the following tube duty cycle is inserted into the dead zone to form a waveform for reference Figure 4 middle The waveform shown.

[0038] However, after inserting the dead zone, the maximum MPV may be exceeded or less than the minimum MPV, that is, outside the range of 0.02~0.98, which will produce a narrow pulse. Therefore, it is necessary to clamp it. The purpose of the clamping process is to limit the modulated signal to within the preset range. In this embodiment, the Limit it to be between maxMPV and minMPV, that is, Limited between 0.02 and 0.98.

[0039] Specifically, S43: performing the modulation signal clamping process according to the narrow pulse threshold upper limit, the narrow pulse threshold lower limit, and the target compensation range includes: Get the equivalent modulation signal ; The target compensation range is formed by the lower limit of the compensation range minZero and the upper limit of the compensation range maxOne; First of all, as an explanation, it can be understood that based on the above example: minZero(0.01)<minMPV(0.02)<maxMPV(0.98)<maxOne(0.99); Therefore, situations that may need to be handled include <minZero, minZero~minMPV; maxMPV~maxOne; >maxOne.

[0040] Therefore, specifically: S43-1: When the equivalent modulation signal exceeds the narrow pulse threshold upper limit, if it is between the narrow pulse threshold upper limit and the compensation range upper limit, output the narrow pulse threshold upper limit (S43-11); if it exceeds the compensation range upper limit, output a predetermined first duty cycle (S43-12); That is, when ;like ; then output ,like , then the output duty cycle is .

[0041] S43-2: When the equivalent modulation signal does not reach the narrow pulse threshold lower limit, if it is between the narrow pulse threshold lower limit and the compensation range lower limit, then output the narrow pulse threshold lower limit (S43-21); if it does not reach the compensation range lower limit, then output a predetermined second duty cycle (S43-22); That is, when ;like , then the output ;like , then the output duty cycle is .

[0042] Based on the above, the example in this embodiment determines Is it greater than 0.98? If it is greater than 0.98, then determine again whether it exceeds 0.99. If it does not exceed 0.99, output 0.98. If it exceeds 0.99, output 1. If it is less than 0.98, then determine again whether it is less than 0.02. If so, then determine again whether it is less than 0.01. If it is less than 0.01, output 0. If it is not less than 0.01, output 0.02.

[0043] In addition to the above cases, the equivalent modulation signal is not processed, that is, when the equivalent modulation signal is between the upper limit of the narrow pulse threshold and the lower limit of the narrow pulse threshold, the equivalent modulation signal is directly output. (S43-3). In other words, the modulation signal within this range is usable and does not require compensation or compensation.

[0044] Based on the above, the equivalent modulation signal after clamping processing is obtained , remove the dead zone margin (i.e. the above ) to output the target modulation signal , , before finally outputting the target modulated signal, it is necessary to remove this influence (remove the dead time margin inserted in the previous step) (S44).

[0045] In this embodiment, the target compensation range is calculated by the upper limit and lower limit of the dead zone narrow pulse threshold, and compensation is performed for the possible occurrence of narrow pulses within the target compensation range to suppress the occurrence of narrow pulses. The specific compensation is achieved by inserting the dead zone, correcting it, and then removing the dead zone. That is, the impact of the dead zone on the output is considered in advance, which can be regarded as a simulated dead zone insertion for control, thereby suppressing the occurrence of narrow pulses during the PWM signal output process and improving safety and control accuracy.

[0046] In a preferred embodiment, when outputting the target modulation signal Afterwards, the dead zone is inserted based on the target modulation signal. As mentioned above, the formation process of the above-mentioned target modulation signal is just similar to the insertion of the analog duty cycle. Its purpose is to consider the influence of the dead zone on the occurrence of narrow pulses. Its purpose is to calculate the target modulation signal that will not affect the dead zone time due to the narrow pulse clamping of the PWM after the dead zone insertion. Therefore, the dead zone can be inserted after the target modulation signal is output. The specific implementation can call the preset dead zone insertion module.

[0047] However, during actual operation, the applicant found that some situations may still need to be corrected after calling the dead zone insertion module. Specifically, after the narrow pulse is clamped and the dead zone time is inserted, the duty cycle may be 0 to 0.02. However, when i>0 (positive), the actual phase voltage duty cycle is determined by the upper tube duty cycle (used to form Figure 4 middle The duty cycle of the lower tube of 0 to 0.02 has no effect on the actual phase voltage duty cycle, so the narrow pulse is clamped directly (that is, the above After inserting the corresponding dead zone, the duty cycle of 0 to 0.02 that still exists is directly clamped to 0 to reduce the risk of narrow pulses.

[0048] Therefore, based on the above, the duty cycle correction includes: when the target modulation signal does not reach the narrow pulse lower limit after being inserted into the dead zone, outputting a predetermined second duty cycle, ie 0. The above correction process can be set to a separate module for processing.

[0049] Based on the above, the control method provided in this embodiment uses a duty cycle adding and then removing method to clamp the duty cycle. Different from the common control process in the prior art, this method considers the influence of different currents, selects the main clamping switch tube according to the current direction, and adjusts the duty cycle of the upper and lower tubes simultaneously. Specifically, the upper and lower tubes are controlled simultaneously according to the target modulation signal. A dead time margin is also reserved to ensure that the output PWM does not have narrow pulses. The dead time is not affected by the narrow pulse clamping of the PWM after the dead time is inserted, and the dead time length is guaranteed to improve control safety and control accuracy.

[0050] To further illustrate that the control method provided by this embodiment is effective, the following table provides simulation values ​​of the duty cycle output by the control method implemented according to this embodiment:

[0051] Based on the above table, it can be seen that the duty cycle output by the control method provided by this application (the last column of the above table) is close to the ideal output, has a good effect, and can effectively suppress the occurrence of narrow pulses.

[0052] As a supplement, the output 0 portion of the duty cycle of the upper tube and the lower tube in the above table reflects the correction after the dead zone insertion.

[0053] Example 2: This embodiment also provides a narrow pulse control device 5 for an inverter to execute the control method of the above-mentioned Example 1. For details, see Figure 5 ,include: The control module 51 is used to obtain the upper and lower limits of the narrow pulse threshold and calculate the target compensation range; obtain a three-phase modulation signal, perform switch tube voltage drop compensation and residual compensation on the three-phase modulation signal, and obtain an intermediate modulation signal; when the intermediate modulation signal is outside the target compensation range, output a predetermined target modulation signal; when the intermediate modulation signal falls within the target compensation range, perform dead zone compensation on the intermediate modulation signal, calculate the equivalent modulation signal after inserting the dead zone, and then perform modulation signal clamping processing according to the upper and lower limits of the narrow pulse threshold and the target compensation range, and then remove the dead zone to output the target modulation signal.

[0054] The execution of the specific control method can refer to the above-mentioned embodiment 1, which will not be repeated here.

[0055] Specifically, it also includes a dead zone insertion module 52 and / or a duty cycle correction module 53 to connect the control module to the inverter drive circuit. The dead zone insertion module is based on the target modulation signal The dead zone is inserted, and the duty cycle correction module executes the target modulation signal. If the target modulation signal does not reach the lower limit of the narrow pulse after the dead zone is inserted, the predetermined second duty cycle, i.e., 0, is output.

[0056] As a supplement, the duty cycle obtained by the duty cycle correction module 53 for PWM control can be further adjusted according to the actual application scenario during actual control. For example, parameters such as the switch on-time can be adjusted according to the actual location of the narrow pulse to adjust the PWM waveform, thereby eliminating the occurrence of other abnormal narrow pulses caused by periodic changes in the PWM waveform. This makes the duty cycle control achieved by suppressing narrow pulses using the above method more effective and safer. It is understood that other common adjustments can also be selected according to the actual application.

[0057] Based on the above, the program is run in the control module to execute the above method to output the target modulation signal By simulating the insertion of dead zone compensation, the narrow pulse generation situation is clamped, and then the dead zone insertion module and the duty cycle correction module are connected to the inverter drive circuit in sequence to control the output of the inverter.

[0058] It is understandable that the device of this embodiment can also be integrated with other common control modules / devices to be used for the operation of power equipment in different scenarios.

[0059] It should be noted that the embodiments of the present invention have better practicability and do not impose any form of limitation on the present invention. Any technician familiar with the field may use the technical content disclosed above to change or modify it into an equivalent effective embodiment. However, any modification or equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A narrow pulse control method for an inverter, characterized in that: include: Obtain the upper and lower limits of the narrow pulse threshold and calculate the target compensation range; Acquire a three-phase modulation signal, perform switch tube voltage drop compensation and residual compensation on the three-phase modulation signal, and obtain an intermediate modulation signal; When the intermediate modulation signal is outside the target compensation range, outputting a predetermined target modulation signal; When the intermediate modulation signal falls within the target compensation range, dead zone compensation is performed on the intermediate modulation signal, and an equivalent modulation signal after inserting the dead zone is calculated. Then, the modulation signal is clamped according to the narrow pulse threshold upper limit, the narrow pulse threshold lower limit, and the target compensation range, and the dead zone is removed to output the target modulation signal.

2. The narrow pulse control method for an inverter according to claim 1, characterized in that: The dead zone compensation is performed on the intermediate modulation signal, and the equivalent modulation signal after the dead zone is inserted is calculated according to the current direction, including: Obtaining a dead zone compensation amount to perform dead zone compensation on the intermediate modulated signal; The current direction is determined according to the dead zone compensation amount, so that the intermediate modulation signal after the dead zone compensation is inserted into the dead zone according to the current direction to obtain an equivalent modulation signal.

3. The narrow pulse control method for an inverter according to claim 2, wherein: A first pulse width modulation wave having a periodic low-level to high-level to low-level change and a second pulse width modulation ratio complementary to the first pulse width modulation wave are preset; wherein the high-level duration is shortened when the first pulse width modulation wave is inserted into the dead zone, and the low-level duration is prolonged when the second pulse width modulation wave is inserted into the dead zone; When the current direction is positive, the intermediate modulation signal after the dead zone compensation is inserted into the dead zone with reference to the first pulse width modulation wave to obtain an equivalent modulation signal; When the current direction is negative, the intermediate modulation signal after the dead zone compensation is inserted into the dead zone with reference to the second pulse width modulation wave to obtain an equivalent modulation signal.

4. The narrow pulse control method for an inverter according to claim 1, wherein: The clamping process of the modulation signal according to the narrow pulse threshold upper limit, the narrow pulse threshold lower limit, and the target compensation range includes: Obtaining an equivalent modulation signal; The target compensation range is formed by a compensation range lower limit and a compensation range upper limit; When the equivalent modulation signal exceeds the narrow pulse threshold upper limit, if it is between the narrow pulse threshold upper limit and the compensation range upper limit, the narrow pulse threshold upper limit is output; if it exceeds the compensation range upper limit, a predetermined first duty cycle is output; When the equivalent modulation signal does not reach the narrow pulse threshold lower limit, if it is between the narrow pulse threshold lower limit and the compensation range lower limit, then the narrow pulse threshold lower limit is output; if it does not reach the compensation range lower limit, then a predetermined second duty cycle is output; When the equivalent modulation signal is between the narrow pulse threshold upper limit and the narrow pulse threshold lower limit, the equivalent modulation signal is output.

5. The narrow pulse control method for an inverter according to claim 1, wherein: Obtaining a residual compensation amount of a previous switching cycle to perform residual compensation on the three-phase modulation signal; After the target modulation signal is output, a residual compensation amount for a subsequent switching cycle is generated according to the target modulation signal and the three-phase modulation signal.

6. The narrow pulse control method for an inverter according to claim 1, characterized in that: Also includes: After the target modulation signal is output, a dead zone is inserted based on the target modulation signal and duty cycle correction is performed.

7. The narrow pulse control method for an inverter according to claim 6, characterized in that: The duty cycle correction comprises: When the target modulation signal does not reach the narrow pulse lower limit after being inserted into the dead zone, a predetermined second duty cycle is output.

8. The narrow pulse control method for an inverter according to claim 1, wherein: When the intermediate modulation signal is outside the target compensation range: If the intermediate modulation signal exceeds an upper limit of a compensation range of a target compensation range, outputting a predetermined first duty cycle; If the intermediate modulation signal does not reach the compensation range lower limit of the target compensation range, a predetermined second duty cycle is output.

9. A narrow pulse control device for an inverter, characterized in that: include: A control module is used to obtain an upper limit and a lower limit of a narrow pulse threshold and calculate a target compensation range; obtain a three-phase modulation signal, perform switch tube voltage drop compensation and residual compensation on the three-phase modulation signal, and obtain an intermediate modulation signal; when the intermediate modulation signal is outside the target compensation range, output a predetermined target modulation signal; when the intermediate modulation signal falls within the target compensation range, perform dead zone compensation on the intermediate modulation signal, calculate an equivalent modulation signal after inserting the dead zone, and then perform modulation signal clamping processing according to the upper limit and lower limit of the narrow pulse threshold and the target compensation range, and then remove the dead zone to output the target modulation signal.

10. The narrow pulse control device for an inverter according to claim 9, characterized in that: It also includes a dead zone insertion module and / or a duty cycle correction module to connect the control module to the inverter drive circuit.

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