SPWM (sinusoidal pulse width modulation) circuit with compensation function

Abstract

The utility model provides an SPWM modulation circuit with a compensation function. The SPWM modulation circuit comprises a modulation wave generation unit, a carrier wave generation unit, a comparison unit, a driving unit, an inversion unit and an output unit. A modulated wave signal generated by the modulated wave generation unit and a carrier signal generated by the carrier generation unit are compared through the comparison unit and then sequentially pass through the driving unit, the inversion unit and the output unit, and an output signal is generated through the output unit; the SPWM modulation line also comprises a regulation and control unit which is electrically connected with the input end of the modulation wave generation unit and is used for outputting a regulation and control signal to the modulation wave generation unit so as to regulate and control the modulation wave signal; one end of the compensation unit is electrically connected with the output end of the output unit, and the other end is electrically connected with the modulation wave generation unit; and the compensation unit generates a corresponding compensation signal according to the output signal and feeds back the compensation signal to the output end of the modulated wave generation unit in real time to be superposed with the modulated wave signal, so that the modulated wave signal is correspondingly compensated.

Description

Technical Field

[0001] The utility model relates to the technical field, in particular to an SPWM modulation circuit with a compensation function. Background Art

[0002] SPWM (Sinusoidal PWM) modulation is a technology that generates a sinusoidal voltage output equivalently by changing the pulse width. SPWM modulation technology is widely used in the field of power electronics, such as AC frequency conversion speed increase, inverter output, etc. It has the advantages of being simple and easy to implement, high reliability, and a wide range of applications. However, in actual applications, it is easy to be unregulated or over-modulated. At this time, the output signal will be distorted or even oscillate, and the total harmonic distortion of the output signal will also increase, thereby affecting the normal use of the back-end load. Utility Model Content

[0003] In view of this, the present application provides an SPWM modulation circuit with a compensation function to maintain the stability of the output signal.

[0004] The present application provides an SPWM modulation circuit with a compensation function, comprising a modulation wave generating unit, a carrier generating unit, a comparison unit, a driving unit, an inverter unit, and an output unit; the input end of the comparison unit is electrically connected to the modulation wave generating unit and the carrier generating unit respectively, and the output end is electrically connected to the driving unit; the input end of the inverter unit is electrically connected to the driving unit, and the output end is electrically connected to the output unit; the modulation wave signal generated by the modulation wave generating unit and the carrier signal generated by the carrier generating unit are compared by the comparison unit and then sequentially pass through the driving unit, the inverter unit, and the output unit to generate an output signal by the output unit; the SPWM modulation circuit also includes:

[0005] a control unit, electrically connected to an input end of the modulation wave generating unit, and configured to output a control signal to the modulation wave generating unit to control the modulation wave signal; and

[0006] A compensation unit, one end of which is electrically connected to the output end of the output unit, and the other end of which is electrically connected to the modulation wave generating unit; the compensation unit generates a corresponding compensation signal according to the output signal and feeds it back to the output end of the modulation wave generating unit in real time, and the compensation signal is superimposed on the modulation wave signal, thereby performing corresponding compensation on the modulation wave signal.

[0007] Furthermore, the modulated wave signal and the carrier signal are respectively input into the comparison unit for comparison, and then input into the driving unit to generate a driving signal, and the driving signal is used to drive the inverter unit to invert, and the inverter unit outputs an inversion signal to the output unit under the drive of the driving signal, so that the output unit generates an output signal.

[0008] Further, the modulation wave generating unit includes a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, and a first comparator; the negative input terminal of the first comparator is grounded through the fourth resistor and the second resistor in sequence; the positive input terminal of the first comparator is grounded through the third capacitor, and is electrically connected to the fifth resistor and the third resistor in sequence, and the end of the third resistor away from the fifth resistor is electrically connected to the first pin through the first capacitor, and is grounded through the first resistor; the output terminal of the first comparator is electrically connected to the second pin through the fourth capacitor and the seventh resistor in sequence, and is electrically connected to the negative input terminal of the first comparator through the sixth resistor, and is electrically connected to between the third resistor and the fifth resistor through the second capacitor; wherein the modulation wave generating unit is electrically connected to the control unit through the first pin, and is electrically connected to the compensation unit through the second pin.

[0009] Further, the carrier generating unit includes a fifth capacitor, a sixth capacitor, an eighth resistor, a ninth resistor, a tenth resistor, and a second comparator; the negative input terminal of the second comparator is electrically connected to the third pin through the ninth resistor and the fifth capacitor in sequence; the positive input terminal of the second comparator is grounded through the tenth resistor; the output terminal of the second comparator is electrically connected to the input terminal of the comparison unit, and is electrically connected to the negative input terminal of the second comparator through the eighth resistor and the sixth capacitor, respectively.

[0010] Furthermore, the compensation unit comprises:

[0011] a sampling unit, electrically connected to the output end of the output unit, and sampling the output signal to obtain an output parameter; and

[0012] A calculation unit, one end of which is electrically connected to the sampling unit, and the other end of which is electrically connected to the modulation wave generating unit; the calculation unit receives the output parameters, calculates according to the output parameters to generate a corresponding compensation signal, and outputs the compensation signal to the output end of the modulation wave generating unit; wherein the output parameters include the amplitude and frequency of the output signal.

[0013] Further, the compensation unit is a circuit with a sampling function, and the compensation unit includes a seventh capacitor, an eighth capacitor, a ninth capacitor, a tenth capacitor, an eleventh resistor, a twelfth resistor, a thirteenth resistor, a fourteenth resistor, a fifteenth resistor, a sixteenth resistor, a seventeenth resistor, and a third comparator; the two ends of the eleventh resistor are grounded through the seventh capacitor and the fifteenth resistor, respectively, and the end of the eleventh resistor close to the fifteenth resistor is electrically connected to the second pin through the fourteenth resistor, and is electrically connected to the second pin through the eighth capacitor and the thirteenth resistor in sequence; the second pin is electrically connected to the negative input terminal of the third comparator, and the compensation unit is electrically connected to the modulation wave generating unit through the second pin; the positive input terminal of the third comparator is grounded through the twelfth resistor; the output terminal of the third comparator is electrically connected to the negative input terminal of the third comparator through the ninth capacitor, the seventeenth resistor, and in sequence through the sixteenth resistor and the tenth capacitor.

[0014] Further, the compensation unit transmits the output parameter to the modulation wave generating unit, the modulation wave generating unit receives the output parameter and transmits the output parameter to the control unit, and the control unit adjusts the control signal according to the output parameter.

[0015] Furthermore, the control unit outputs a control signal to the modulation wave generating unit to control the modulation wave signal, thereby controlling the modulation ratio; wherein the modulation ratio is the ratio of the modulation wave signal to the carrier signal.

[0016] Furthermore, the modulation ratio is less than 1.

[0017] Further, the control unit is electrically connected to a first pin, the control unit is electrically connected to the modulation wave generating unit via the first pin, and the control unit outputs a control signal with a variable duty cycle for controlling the modulation wave generating unit.

[0018] The above-mentioned SPWM modulation circuit with compensation function generates a corresponding compensation signal according to the output signal through the compensation unit, and feeds back the compensation signal to the output end of the modulation wave generating unit to compensate the modulation wave signal, thereby generating a closed-loop feedback control, thereby maintaining the stability of the output signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0020] Figure 1It is a structural schematic diagram of an SPWM modulation circuit with compensation function provided by the present application.

[0021] Figure 2 This is a circuit schematic diagram of the modulation wave generating unit provided in this application.

[0022] Figure 3 This is a circuit diagram of the carrier generation unit provided in this application.

[0023] Figure 4 It is a circuit schematic diagram of the feedback unit provided in this application.

[0024] Figure 5 It is a circuit schematic diagram of the control unit provided in this application.

[0025] Description of the accompanying drawings:

[0026] SPWM modulation circuit 100 drive unit 4

[0027] Modulation wave generating unit 1 Inverter unit 5

[0028] First capacitor C222 Output unit 6

[0029] Second capacitor C223 Compensation unit 7

[0030] The third capacitor C224 sampling unit 71

[0031] Fourth capacitor C225 Calculation unit 72

[0032] First resistor R258 Seventh capacitor C226

[0033] The second resistor R259 and the eighth capacitor C227

[0034] The third resistor R260 and the ninth capacitor C232

[0035] Fourth resistor R261 Tenth capacitor C233

[0036] Fifth resistor R262 Eleventh resistor R265

[0037] Sixth resistor R263 Twelfth resistor R266

[0038] Seventh resistor R264 Thirteenth resistor R267

[0039] The first comparator U1 The fourteenth resistor R268

[0040] Carrier generating unit 2 Fifteenth resistor R269

[0041] The fifth capacitor C234 and the sixteenth resistor R272

[0042] Sixth capacitor C235 Seventeenth resistor R273

[0043] The eighth resistor R274 The third comparator U3

[0044] The ninth resistor R275 control unit 8

[0045] The tenth resistor R276 The first pin SINE.PWM

[0046] The second comparator U2 second pin SINE

[0047] Comparison unit 3 The third pin CLOCK

[0048] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0049] In order to make the purpose, technical solutions and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present application.

[0050] The terms "first", "second", "third", "fourth", etc. (if any) in the specification and claims of this application and the above-mentioned drawings are used to distinguish similar planning objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate. In other words, the described embodiments are implemented according to a sequence other than that illustrated or described herein. In addition, the terms "including" and "having" and any of their variations may also include other content. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to only those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0051] It should be noted that the descriptions of "first", "second", etc. in this application are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in this field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0052] Please see Figure 1 , Figure 1 1 is a schematic diagram of the structure of an SPWM modulation circuit with compensation function provided by the present application. The present application provides an SPWM modulation circuit 100 with compensation function, including a modulation wave generating unit 1, a carrier generating unit 2, a comparison unit 3, a drive unit 4, an inverter unit 5, an output unit 6, a compensation unit 7, and a control unit 8. The control unit 8 is electrically connected to the modulation wave generating unit 1. The modulation wave generating unit 1 and the carrier generating unit 2 are electrically connected to the comparison unit 3 respectively. The comparison unit 3, the drive unit 4, the inverter unit 5, and the output unit 6 are electrically connected in sequence. The output unit 6 is electrically connected to the load. One end of the compensation unit 7 is electrically connected to the output end of the output unit 6, and the other end is electrically connected to the modulation wave generating unit 1. The control unit 8 is used to control the modulation wave generating unit 1. The modulation wave signal generated by the modulation wave generating unit 1 and the carrier signal generated by the carrier generating unit 2 are compared by the comparison unit 3 and then sequentially pass through the drive unit 4, the inverter unit 5, and the output unit 6 to generate a corresponding output signal. The compensation unit 7 compensates the SPWM modulation circuit 100 according to the output signal.

[0053] The control unit 8 is used to control the modulation wave generating unit 1. Specifically, the control unit 8 outputs a control signal to the modulation wave generating unit 1 to control the modulation wave signal, and the control signal is an SPWM signal with a variable duty cycle. The control unit 8 controls the modulation ratio by controlling the modulation wave signal. Among them, the modulation ratio is the ratio of the modulation wave signal to the carrier signal. In the present application, the modulation ratio is less than 1, and the modulation ratio is related to the size of the load connected to the output unit 6. When the load is small, the modulation ratio is controlled to be less than 1. When the load is large, the modulation ratio is controlled to be infinitely close to but not greater than 1 to avoid over-modulation, so as to maintain the stability of the output signal while effectively reducing the harmonic components and preventing the output signal waveform from oscillating.

[0054] The input end of the modulation wave generating unit 1 is electrically connected to the control unit 8, and the output end is electrically connected to the comparison unit 3. The modulation wave generating unit 1 receives the control signal and outputs the corresponding modulation wave signal to the control signal. In the present application, the modulation wave signal is a sine wave signal with a fixed frequency and amplitude, which is used to compare with the carrier signal to generate an SPWM signal (sinusoidal pulse width modulation signal).

[0055] The output end of the carrier generating unit 2 is electrically connected to the comparison unit 3, and the carrier generating unit 2 is used to output a carrier signal. In the present application, the carrier signal is a triangular wave with a fixed frequency and amplitude, which has a higher frequency and is used to compare with the modulation wave signal to generate an SPWM signal. Among them, the frequency of the carrier signal determines the on-off frequency of the switch tube in the inverter unit 5.

[0056] The input end of the comparison unit 3 is electrically connected to the modulation wave generating unit 1 and the carrier generating unit 2 respectively, and the output end is electrically connected to the driving unit 4. The comparison unit 3 is used to compare the modulation wave signal with the carrier signal, generate an SPWM signal and output it to the driving unit 4. Specifically, when the amplitude of the modulation wave signal is greater than the amplitude of the carrier signal, a high level is output, and when the amplitude of the modulation wave signal is less than the amplitude of the carrier signal, a low level is output, thereby obtaining an SPWM signal with a shape similar to the modulation wave signal, and the SPWM signal is used to control the on and off of the switch tube in the inverter unit 5.

[0057] The input end of the driving unit 4 is electrically connected to the comparison unit 3, and the output end is electrically connected to the inverter unit 5. The driving unit 4 receives the SPWM signal output by the comparison unit 3, and converts the SPWM signal into a driving signal capable of driving the switch tube in the inverter unit 5 to work. The driving unit 4 generally includes a power amplifier circuit and an isolation circuit to ensure that the driving signal can accurately drive the switch tube in the inverter unit 5 to turn on and off.

[0058] The input end of the inverter unit 5 is electrically connected to the drive unit 4, and the output end is electrically connected to the output unit 6. The inverter unit 5 receives the drive signal output by the drive unit 4, and under the control of the drive signal, the switch tube inside the inverter unit 5 is turned on and off at a certain frequency, so as to generate a corresponding AC inverter signal at the output end and transmit it to the output unit 6.

[0059] The input end of the output unit 6 is electrically connected to the inverter unit 5, and the output end is electrically connected to the load (not shown) and the compensation unit 7. The output unit 6 is used to filter and adjust the AC inverter signal output by the inverter unit 5, obtain the final output signal and output it to the load to provide the power required for the load to work, and output it to the compensation unit 7 so that the compensation unit 7 generates a corresponding compensation signal. In the present application, the output unit 6 includes a filter circuit, a transformer, etc. to improve the waveform quality and stability of the output signal.

[0060] One end of the compensation unit 7 is electrically connected to the output end of the output unit 6, and the other end is electrically connected to the modulation wave generating unit 1. The compensation unit 7 includes a sampling unit 71 and a calculation unit 72. The sampling unit 71 is electrically connected to the output end of the output unit 6, and samples the output signal to obtain an output parameter. One end of the calculation unit 72 is electrically connected to the sampling unit 71, and the other end is electrically connected to the modulation wave generating unit 1. The calculation unit 72 receives the output parameter obtained by the sampling unit 71 and calculates and generates a corresponding compensation signal according to the output parameter. The output parameter includes the amplitude and frequency of the output signal. The calculation unit 72 outputs the compensation signal to the output end of the modulation wave generating unit 1 to be superimposed with the modulation wave signal, thereby compensating the modulation wave signal, and then compensating for the error or distortion generated during the SPWM modulation process, so as to improve the accuracy and stability of the output signal. In the present application, the compensation unit 7 transmits the output parameter to the modulation wave generating unit 1, and the modulation wave generating unit 1 receives the output parameter and transmits the output parameter to the control unit 8, and the control unit 8 adjusts the control signal according to the output parameter, thereby adjusting the modulation wave signal.

[0061] Furthermore, the working principle of the SPWM modulation circuit 100 with compensation function is as follows: during initial operation, the control unit 8 first sends a control signal with a variable duty cycle to the modulation wave generating unit 1, so that the modulation wave generating unit 1 generates a corresponding modulation wave signal, and at the same time, the carrier generating unit 2 generates a carrier signal, and the modulation wave signal and the carrier signal are respectively input to the comparison unit 3 for comparison to output the SPWM signal, and the driving unit 4 receives the SPWM signal and converts the SPWM signal into a driving signal to drive the operation of the switch tube in the inverter unit 5, so that the inverter unit 5 outputs an alternating inverter signal under the drive of the driving signal, and the output unit 6 receives the inverter signal and filters and adjusts the inverter signal to obtain an output signal. The compensation unit 7 samples the output signal and obtains an output parameter, and generates a corresponding compensation signal according to the output signal and feeds it back to the output end of the modulation wave generating unit 1 in real time. At the same time, the control unit 8 adjusts the control signal according to the output parameter and sends the control signal to the modulation wave generating unit 1 again to generate a corresponding modulation wave signal, and the modulation wave signal is superimposed with the compensation signal, so as to compensate the modulation wave signal accordingly. The entire modulation process is repeated, thus generating a closed-loop feedback control to maintain the stability of the output signal.

[0062] The specific circuit structure of the modulation wave generating unit 1, the carrier generating unit 2, the compensation unit 7, and the control unit 8 will be introduced in detail below. The specific circuit structure of the comparison unit 3, the driving unit 4, the inverter unit 5, and the output unit 6 will not be discussed in detail here.

[0063] Please refer to Figure 2 , Figure 2: This is a circuit schematic diagram of the modulation wave generating unit 1 provided by the present application. The modulation wave generating unit 1 includes a first capacitor C222, a second capacitor C223, a third capacitor C224, a fourth capacitor C225, a first resistor R258, a second resistor R259, a third resistor R260, a fourth resistor R261, a fifth resistor R262, a sixth resistor R263, a seventh resistor R264, and a first comparator U1. The negative input terminal of the first comparator U1 is grounded through the fourth resistor R261 and the second resistor R259 in sequence. The positive input terminal of the first comparator U1 is grounded through the third capacitor C224, and the positive input terminal of the first comparator U1 is electrically connected to the fifth resistor R262 and the third resistor R260 in sequence. The end of the third resistor R260 away from the fifth resistor R262 is electrically connected to the first pin SINE.PWM through the first capacitor C222, and the end of the third resistor R260 away from the fifth resistor R262 is grounded through the first resistor R258. The output end of the first comparator U1 is electrically connected to the second pin SINE through the fourth capacitor C225 and the seventh resistor R264 in sequence, and the output end of the first comparator U1 is electrically connected to the negative input end of the first comparator U1 through the sixth resistor R263, and the output end of the first comparator U1 is electrically connected between the third resistor R260 and the fifth resistor R262 through the second capacitor C223. Among them, the modulation wave generating unit 1 is electrically connected to the control unit 8 through the first pin SINE.PWM, and the modulation wave generating unit 1 is electrically connected to the compensation unit 7 through the second pin SINE.

[0064] Please refer to Figure 3 , Figure 3 : It is a circuit diagram of the carrier generating unit 2 provided by the present application. The carrier generating unit 2 includes a fifth capacitor C234, a sixth capacitor C235, an eighth resistor R274, a ninth resistor R275, a tenth resistor R276, and a second comparator U. The negative input terminal of the second comparator U2 is electrically connected to the third pin CLOCK through the ninth resistor R275 and the fifth capacitor C234 in sequence. The third pin CLOCK is electrically connected to a clock source for providing a clock signal required by the carrier generating unit 2. The positive input terminal of the second comparator U2 is grounded through the tenth resistor R276. The output terminal of the second comparator U2 is electrically connected to the input terminal of the comparison unit 3, and the output terminal of the second comparator U2 is electrically connected to the negative input terminal of the second comparator U2 through the eighth resistor R274 and the sixth capacitor C235, respectively.

[0065] Please refer to Figure 4 , Figure 4: is a circuit schematic diagram of the compensation unit 7 provided in the present application. The compensation unit 7 is a circuit with a sampling function, and the compensation unit 7 includes a seventh capacitor C226, an eighth capacitor C227, a ninth capacitor C232, a tenth capacitor C233, an eleventh resistor R265, a twelfth resistor R266, a thirteenth resistor R267, a fourteenth resistor R268, a fifteenth resistor R269, a sixteenth resistor R272, a seventeenth resistor R273, and a third comparator U3. Both ends of the eleventh resistor R265 are grounded through the seventh capacitor C226 and the fifteenth resistor R269, respectively, and one end of the eleventh resistor R265 close to the fifteenth resistor R269 is electrically connected to the second pin SINE through the fourteenth resistor R268, and one end of the eleventh resistor R265 close to the fifteenth resistor R269 is electrically connected to the second pin SINE through the eighth capacitor C227 and the thirteenth resistor R267 in sequence. The second pin SINE is electrically connected to the negative input terminal of the third comparator U3. The compensation unit 7 is electrically connected to the modulation wave generating unit 1 through the second pin SINE. The positive input terminal of the third comparator U3 is grounded through the twelfth resistor R266. The output terminal of the third comparator U3 is electrically connected to the negative input terminal of the third comparator U3 through the ninth capacitor C232, the seventeenth resistor R273, and the sixteenth resistor R272 and the tenth capacitor C233 in sequence.

[0066] Please refer to Figure 5 , Figure 5 : is a circuit schematic diagram of the control unit 8 provided in the present application. The control unit 8 is electrically connected to the first pin SINE.PWM, and the control unit 8 is electrically connected to the modulation wave generating unit 1 through the first pin SINE.PWM. The control unit 8 outputs a control signal with a variable duty cycle, which is used to control the modulation wave generating unit 1. In this embodiment, the control unit 8 is a chip of the LQFP100SM model, including a microprocessor, a DSP (digital signal processor) and other control devices, and adjusts the control signal in real time according to external instructions or system requirements.

[0067] In the above embodiment, the compensation unit generates a corresponding compensation signal according to the output signal, and feeds the compensation signal back to the output end of the modulation wave generating unit to compensate the modulation wave signal, thereby generating a closed-loop feedback control to maintain the stability of the output signal.

[0068] The above are only preferred embodiments of the utility model, but do not limit the patent scope of the utility model. Although the utility model is described in detail with reference to the above embodiments, for those skilled in the art, they can still modify the technical solutions recorded in the above specific implementations, or replace some of the technical features with equivalents. Any equivalent structure made by using the contents of the utility model specification and drawings, directly or indirectly used in other related technical fields, is also within the scope of protection of the utility model patent.

Claims

1. A SPWM modulation circuit with compensation function, characterized in that: The invention comprises a modulation wave generating unit, a carrier generating unit, a comparison unit, a driving unit, an inverter unit, and an output unit; the input end of the comparison unit is electrically connected to the modulation wave generating unit and the carrier generating unit respectively, and the output end is electrically connected to the driving unit; the input end of the inverter unit is electrically connected to the driving unit, and the output end is electrically connected to the output unit; the modulation wave signal generated by the modulation wave generating unit and the carrier signal generated by the carrier generating unit are compared by the comparison unit and then sequentially pass through the driving unit, the inverter unit, and the output unit and generate an output signal by the output unit; The SPWM modulation circuit also includes: a control unit, electrically connected to an input end of the modulation wave generating unit, and configured to output a control signal to the modulation wave generating unit to control the modulation wave signal; and A compensation unit, one end of which is electrically connected to the output end of the output unit, and the other end of which is electrically connected to the modulation wave generating unit; the compensation unit generates a corresponding compensation signal according to the output signal and feeds it back to the output end of the modulation wave generating unit in real time, and the compensation signal is superimposed on the modulation wave signal, thereby performing corresponding compensation on the modulation wave signal.

2. The SPWM modulation circuit with compensation function according to claim 1, characterized in that: The modulated wave signal and the carrier signal are respectively input into the comparison unit for comparison, and then input into the driving unit to generate a driving signal, wherein the driving signal is used to drive the inverter unit to perform inversion, and the inverter unit outputs an inversion signal to the output unit under the drive of the driving signal, so that the output unit generates an output signal.

3. The SPWM modulation circuit with compensation function according to claim 1, characterized in that: The modulation wave generating unit includes a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, and a first comparator; the negative input terminal of the first comparator is grounded through the fourth resistor and the second resistor in sequence; the positive input terminal of the first comparator is grounded through the third capacitor, and is electrically connected to the fifth resistor and the third resistor in sequence, and the end of the third resistor away from the fifth resistor is electrically connected to the first pin through the first capacitor, and is grounded through the first resistor; the output terminal of the first comparator is electrically connected to the second pin through the fourth capacitor and the seventh resistor in sequence, and is electrically connected to the negative input terminal of the first comparator through the sixth resistor, and is electrically connected to between the third resistor and the fifth resistor through the second capacitor; wherein the modulation wave generating unit is electrically connected to the control unit through the first pin, and is electrically connected to the compensation unit through the second pin.

4. The SPWM modulation circuit with compensation function according to claim 1, characterized in that: The carrier generating unit includes a fifth capacitor, a sixth capacitor, an eighth resistor, a ninth resistor, a tenth resistor, and a second comparator; the negative input terminal of the second comparator is electrically connected to the third pin through the ninth resistor and the fifth capacitor in sequence; the positive input terminal of the second comparator is grounded through the tenth resistor; the output terminal of the second comparator is electrically connected to the input terminal of the comparison unit, and is electrically connected to the negative input terminal of the second comparator through the eighth resistor and the sixth capacitor respectively.

5. The SPWM modulation circuit with compensation function according to claim 1, characterized in that: The compensation unit comprises: a sampling unit, electrically connected to the output end of the output unit, and sampling the output signal to obtain an output parameter; and A calculation unit, one end of which is electrically connected to the sampling unit, and the other end of which is electrically connected to the modulation wave generating unit; the calculation unit receives the output parameters, calculates according to the output parameters to generate a corresponding compensation signal, and outputs the compensation signal to the output end of the modulation wave generating unit; wherein the output parameters include the amplitude and frequency of the output signal.

6. The SPWM modulation circuit with compensation function according to claim 5, characterized in that: The compensation unit is a circuit with a sampling function, and the compensation unit includes a seventh capacitor, an eighth capacitor, a ninth capacitor, a tenth capacitor, an eleventh resistor, a twelfth resistor, a thirteenth resistor, a fourteenth resistor, a fifteenth resistor, a sixteenth resistor, a seventeenth resistor, and a third comparator; both ends of the eleventh resistor are grounded through the seventh capacitor and the fifteenth resistor, respectively, and an end of the eleventh resistor close to the fifteenth resistor is electrically connected to the second pin through the fourteenth resistor, and is electrically connected to the second pin through the eighth capacitor and the thirteenth resistor in sequence; the second pin is electrically connected to the negative input terminal of the third comparator, and the compensation unit is electrically connected to the modulation wave generating unit through the second pin; the positive input terminal of the third comparator is grounded through the twelfth resistor; the output terminal of the third comparator is electrically connected to the negative input terminal of the third comparator through the ninth capacitor, the seventeenth resistor, and in sequence through the sixteenth resistor and the tenth capacitor.

7. The SPWM modulation circuit with compensation function according to claim 5, characterized in that: The compensation unit transmits the output parameter to the modulation wave generating unit, the modulation wave generating unit receives the output parameter and transmits the output parameter to the control unit, and the control unit adjusts the control signal according to the output parameter.

8. The SPWM modulation circuit with compensation function according to claim 7, characterized in that: The control unit outputs a control signal to the modulation wave generating unit to control the modulation wave signal, thereby controlling the modulation ratio; wherein the modulation ratio is the ratio of the modulation wave signal to the carrier signal.

9. The SPWM modulation circuit with compensation function according to claim 8, characterized in that: The modulation ratio is less than 1.

10. The SPWM modulation circuit with compensation function according to claim 7, characterized in that: The control unit is electrically connected to the first pin, and the control unit is electrically connected to the modulation wave generating unit through the first pin. The control unit outputs a control signal with a variable duty cycle for controlling the modulation wave generating unit.

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