Inverter output control system

Abstract

The application discloses an inverter output control system, a voltage effective value loop of which comprises: a first loop branch for obtaining a first branch output value according to a feedback voltage effective value and a voltage effective value reference; a second loop branch for obtaining a second branch output value according to a difference between the voltage effective value and a sum of the voltage effective value reference and a voltage bias value, the second branch output value being negative when the voltage effective value is greater than the sum of the voltage effective value reference and the voltage bias value; and a third loop branch for obtaining a third branch output value according to a difference between the voltage effective value and a difference between the voltage effective value reference and the voltage bias value, the third branch output value being positive when the voltage effective value is less than the difference between the voltage effective value reference and the voltage bias value. An output value of the voltage effective value loop is obtained according to a sum of the first branch output value, the second branch output value and the third branch output value. The system can improve a voltage effective value recovery rate of a real-time inverter voltage value at the time of instantaneous full load.

Description

Technical Field

[0001] The present technology relates to the field of inverter output control, and in particular to an inverter output control system. Background Art

[0002] The existing control schemes for inline or T-type inverters take too long to recover the effective value of the real-time inverter voltage when the inverter is fully loaded (instantly making the inverter output power reach the rated power), and have poor dynamics, and may even fail to meet the standards. Summary of the Invention

[0003] The present application aims to provide an inverter output control system that can solve the technical problems in the above-mentioned background technology of long recovery time of effective value of real-time inverter voltage and poor dynamics when instantaneously fully loaded.

[0004] To achieve the above objectives, the present application provides an inverter output control system, comprising a phase-locked module, a voltage RMS loop, and a real-time inversion loop; the phase-locked module is configured to generate a trigonometric function value corresponding to a phase-locked angle based on a given voltage RMS value; the real-time inversion loop is configured to output a regulation signal to the inverter based on the inverter's real-time inverter voltage value, positive and negative bus voltage feedforward values, and a voltage real-time value reference; the voltage real-time value reference is obtained by multiplying the output value of the voltage RMS loop, the voltage RMS reference obtained based on the given voltage RMS value, and the inverter voltage phase; the inverter voltage phase is obtained by the trigonometric function value and a DC current regulation value obtained based on the real-time inverter current value output by the inverter; the voltage RMS loop comprises:

[0005] a first loop branch, the first loop branch being configured to obtain a first branch output value according to a feedback voltage effective value and the voltage effective value reference, the voltage effective value being obtained according to the real-time inverter voltage value;

[0006] a second loop branch, the second loop branch being configured to obtain a second branch output value according to a difference between the voltage effective value and the voltage effective value, wherein when the voltage effective value is greater than the sum of the voltage effective value reference and the voltage offset value, the second branch output value is a negative number, otherwise it is 0;

[0007] a third loop branch, the third loop branch being configured to obtain a third branch output value according to a difference between the voltage effective value reference, the voltage effective value, and the voltage offset value, wherein when the voltage effective value is less than the difference between the voltage effective value reference and the voltage offset value, the third branch output value is a positive number, otherwise it is 0;

[0008] The output value of the voltage effective value loop is obtained according to the sum of the first branch output value, the second branch output value and the third branch output value.

[0009] The voltage RMS loop of the present application includes a first loop branch, a second loop branch, and a third loop branch. The first loop branch is used to obtain a first branch output value based on the feedback voltage RMS and the voltage RMS reference, and the voltage RMS is obtained based on the real-time inversion voltage value. The second loop branch is used to obtain a second branch output value based on the difference between the sum of the voltage RMS reference and the voltage bias value and the voltage RMS. When the voltage RMS is greater than the sum of the voltage RMS reference and the voltage bias value, the second branch output value is a negative number, otherwise it is 0. The third loop branch is used to obtain a third branch output value based on the difference between the voltage RMS reference and the voltage RMS and the voltage bias value. When the voltage RMS is less than the difference between the voltage RMS reference and the voltage bias value, the third branch output value is a positive number, otherwise it is 0. The output value of the voltage RMS loop is obtained based on the sum of the first branch output value, the second branch output value, and the third branch output value. When the effective voltage value of the real-time inverter voltage value drops rapidly to a value less than the difference between the effective voltage value reference and the voltage bias value, the third loop branch can respond quickly to increase the effective voltage value of the real-time inverter voltage value, and when the effective voltage value of the real-time inverter voltage value rises rapidly to a value greater than the effective voltage value reference plus the voltage bias value, the second loop branch can respond quickly to reduce the effective voltage value of the real-time inverter voltage value, thereby improving the response rate of the effective voltage value loop and having better dynamics.

[0010] Optionally, the second loop branch includes a first negative feedback regulator and a first limiter, and the third loop branch includes a second negative feedback regulator and a second limiter;

[0011] The input value of the first negative feedback regulator is the sum of the voltage effective value reference and the voltage bias value minus the voltage effective value, and the input value of the second negative feedback regulator is the voltage effective value reference minus the voltage effective value and the voltage bias value;

[0012] The input value of the first limiter is the output value of the first negative feedback regulator, and the output value of the first limiter is the output value of the second branch; the input value of the second limiter is the output value of the second negative feedback regulator, and the output value of the second limiter is the output value of the third branch;

[0013] The limiting range of the first limiter is less than or equal to 0, and the limiting range of the second limiter is greater than or equal to 0.

[0014] Optionally, the first loop branch includes a third negative feedback regulator and a third limiter;

[0015] The input value of the third negative feedback regulator is the difference between the voltage effective value and the voltage effective value reference;

[0016] The input value of the third limiter is the output value of the third negative feedback regulator, and the output value of the third limiter is the first branch output value;

[0017] The lower limit value of the limiting range of the third limiter is greater than the upper limit value of the second limiter.

[0018] Optionally, the first negative feedback regulator, the second negative feedback regulator and the third negative feedback regulator are PI regulators, and the parameters of the first negative feedback regulator and the second negative feedback regulator are greater than the parameters of the third negative feedback regulator.

[0019] Optionally, the voltage effective value loop further includes a fourth limiter;

[0020] The fourth limiter limits the sum of the first branch output value, the second branch output value and the third branch output value, and the output value of the fourth limiter is the output value of the voltage effective value loop;

[0021] The limiting range of the fourth limiter is the same as the limiting range of the third limiter.

[0022] Optionally, the real-time inversion loop includes a duty cycle calculation branch and a voltage real-time value feedback branch;

[0023] The regulating signal is obtained according to the output value of the duty cycle calculation branch, the output value of the duty cycle calculation branch is obtained based on the positive and negative bus voltage feedforward values, the voltage real-time value reference and the output value of the voltage real-time value feedback branch, and the output value of the voltage real-time value feedback branch is obtained based on the real-time inverter voltage value;

[0024] Optionally, the calculation formula of the voltage real-time value reference is:

[0025] Vinvref=(sinθ-IdcLoopOut)·Vrms_Ref·VrmsLoopOut;

[0026] Among them, Vinvref is the voltage real-time value reference, IdcLoopOut is the current DC component adjustment value, sinθ is the trigonometric function value, Vrms_Ref is the voltage effective value reference, VrmsLoopOut is the output value of the voltage effective value loop, and (sinθ-IdcLoopOut) is the inverter voltage phase.

[0027] Optionally, the duty cycle calculation branch includes a fourth negative feedback regulator, and an input value of the fourth negative feedback regulator is a difference between the voltage real-time value reference and the output value of the voltage real-time value feedback branch;

[0028] The formula for calculating the output value of the duty cycle calculation branch is:

[0029] P=(V+Vinref)·BusFeedBack;

[0030] Wherein, V is the output value of the fourth negative feedback regulator, Vinref is the voltage real-time value reference, BusFeedBack is the positive and negative bus voltage feedforward value, and P is the output value of the duty cycle calculation branch;

[0031] The real-time inverter loop further includes a PWM module, which is configured to generate the regulating signal according to the output value P of the duty cycle calculation branch.

[0032] Optionally, the real-time inversion loop further includes a first filter and a fifth negative feedback regulator;

[0033] The first filter is used to filter the real-time inverter current value to obtain a current DC component;

[0034] The fifth negative feedback regulator is used to obtain the current DC component adjustment value according to the current DC component.

[0035] Optionally, the voltage real-time value feedback branch includes a second filter and a sixth negative feedback regulator;

[0036] The second filter is used to obtain a voltage DC component from the real-time inverter voltage value;

[0037] The sixth negative feedback regulator is used to obtain a voltage DC component adjustment value according to the voltage DC component;

[0038] The output value of the voltage real-time value feedback branch is the sum of the real-time inverter voltage value and the voltage DC component adjustment value. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 This is a schematic diagram of the topological structure of the inverter according to an embodiment of the present application.

[0040] Figure 2 This is a schematic diagram of the topological structure of the inverter output control system according to an embodiment of the present application. DETAILED DESCRIPTION

[0041] In order to explain the technical content, structural features, achieved objectives and effects of this application in detail, the following is a detailed description in conjunction with the implementation methods and the accompanying drawings.

[0042] The inverter 4 involved in this application can be implemented using an IGBT (Insulate-Gate Bipolar Transistor) module. Optionally, an IGBT module with a damping diode can be used. Of course, this is not limited to this.

[0043] In some embodiments, the inverter 4 may be a three-level in-line topology.

[0044] See also Figure 1 Specifically, the inverter 4 includes three parallel switch branches, each of which includes a first diode V11 / V21 / V31, a second diode V12 / V22 / V32, and a first switch Q11 / Q21 / Q31, a second switch Q12 / Q22 / Q32, a third switch Q13 / Q23 / Q33, and a fourth switch Q14 / Q24 / Q34 connected in series. The first switch Q11 / Q21 / Q31 is connected to the DC positive pole, the fourth switch Q14 / Q24 / Q34 is connected to the DC negative pole, the anode of the first diode V11 / V21 / V31 is connected to the electrical neutral pole N, and the cathode is connected between the first switch Q11 / Q21 / Q31 and the second switch Q12 / Q22 / Q32. The cathode of the second diode V12 / V22 / V32 is connected to the electrical neutral pole N, and the anode is connected between the third switch Q13 / Q23 / Q33 and the fourth switch Q14 / Q24 / Q34. One end of the inductor L1 / L2 / L3 is connected between the second switch Q12 / Q22 / Q32 and the corresponding third switch Q13 / Q23 / Q33. The other end of the inductor L1 / L2 / L3 is connected to one end of the third capacitor C31 / C32 / C33. The other end of the third capacitor C31 / C32 / C33 is connected to the electrical neutral pole N. Specifically, a first capacitor C1 is connected between the DC positive electrode and the electrically neutral electrode N, and a second capacitor C2 is connected between the electrically neutral electrode N and the DC negative electrode.

[0045] The negative poles of the inductors L1 / L2 / L3 of the three circuit branches are connected to the signal lines corresponding to the R, S and T signals respectively, and the output signal of the inverter 4 is output by these three signal lines. The third capacitors C31 / C32 / C33 respectively output the real-time inverter voltage value of the inverter 4, and the inductors L1 / L2 / L3 respectively output the real-time inverter current value of the inverter 4.

[0046] More specifically, the first switch Q11 / Q21 / Q31, the second switch Q12 / Q22 / Q32, the third switch Q13 / Q23 / Q33 and the fourth switch Q14 / Q24 / Q34 can be IGBT modules. The opening and closing of the above switches can be controlled by PWM (Pulse-Width Modulation) signals to convert the circuit DC signal into a real-time inverter voltage value (AC signal) output.

[0047] The following example takes the control of one switch branch of the inverter 4 to output a real-time inverter voltage value as an example. The same applies to other switch branches and will not be described in detail.

[0048] See also Figure 1 and Figure 2 The embodiment of the present application discloses an inverter output control system, including a phase-locked module 2, a voltage effective value loop 1, and a real-time inverter loop 3; the phase-locked module 2 is used to generate a trigonometric function value corresponding to a phase-locked angle according to a given voltage effective value; the real-time inverter loop 3 is used to output a regulation signal to the inverter 4 according to the real-time inverter voltage value of the inverter 4, the positive and negative bus voltage feedforward values, and the real-time voltage reference; the real-time voltage reference is obtained by multiplying the output value of the voltage effective value loop 1, the voltage effective value reference obtained based on the given voltage effective value, and the inverter voltage phase; the inverter voltage phase is obtained according to the trigonometric function value and a DC current regulation value obtained based on the real-time inverter current value output by the inverter 4; the voltage effective value loop 1 includes:

[0049] A first loop branch 11 is used to obtain a first branch output value according to a feedback voltage effective value and a voltage effective value reference, wherein the voltage effective value is obtained according to a real-time inverter voltage value;

[0050] The second loop branch 12 is used to obtain a second branch output value according to the difference between the sum of the voltage RMS reference value and the voltage offset value and the voltage RMS value. When the voltage RMS value is greater than the sum of the voltage RMS reference value and the voltage offset value, the second branch output value is a negative number, otherwise it is 0;

[0051] The third loop branch 13 is used to obtain a third branch output value according to the difference between the voltage RMS reference, the voltage RMS value, and the voltage offset value. When the voltage RMS value is less than the difference between the voltage RMS reference and the voltage offset value, the third branch output value is a positive number, otherwise it is 0;

[0052] The output value of the voltage effective value loop 1 is obtained according to the sum of the first branch output value, the second branch output value and the third branch output value.

[0053] The voltage RMS loop 1 of the existing inverter output control system uses the first branch output value as the output value of the voltage RMS loop 1, which makes the recovery time of the voltage RMS of the real-time inverter voltage value too long when the voltage is instantaneously fully loaded, and the dynamic performance is poor. However, the voltage RMS loop 1 of the present application obtains the output value of the voltage RMS loop 1 by the sum of the first branch output value, the second branch output value, and the third branch output value. When the voltage RMS is greater than the sum of the voltage RMS reference and the voltage bias value, the output value of the second branch is negative, otherwise it is 0. When the voltage RMS is less than the difference between the voltage RMS reference and the voltage bias value, the output value of the third branch is positive, otherwise it is 0. When the effective voltage value of the real-time inverter voltage value rapidly drops to a value less than the difference between the effective voltage value reference and the voltage bias value, the third loop branch 13 can quickly respond to increase the effective voltage value of the real-time inverter voltage value. When the effective voltage value of the real-time inverter voltage value rapidly rises to a value greater than the effective voltage value reference plus the voltage bias value, the second loop branch 12 can quickly respond to reduce the effective voltage value of the real-time inverter voltage value, thereby improving the response rate of the effective voltage value loop 1 and having better dynamics. In addition, the system adds the second loop branch 12 and the third loop branch 13 to the original effective voltage value loop 1 without changing the branches of the original inverter output control system, and does not destroy the stability of the original inverter output control system.

[0054] See also Figure 2 In some embodiments, the second loop branch 12 includes a first negative feedback regulator 121 and a first limiter 122, and the third loop branch 13 includes a second negative feedback regulator 131 and a second limiter 132. The input value of the first negative feedback regulator 121 is the sum of the voltage RMS reference and the voltage offset value minus the voltage RMS value, and the input value of the second negative feedback regulator 131 is the voltage RMS reference minus the voltage RMS value and the voltage offset value. The input value of the first limiter 122 is the output value of the first negative feedback regulator 121, and the output value of the first limiter 122 is the second branch output value. The input value of the second limiter 132 is the output value of the second negative feedback regulator 131, and the output value of the second limiter 132 is the third branch output value. The limiting range of the first limiter 122 is less than or equal to 0, and the limiting range of the second limiter 132 is greater than or equal to 0.

[0055] Specifically, the first loop branch 11 includes a third negative feedback regulator 111 and a third limiter 112. The input value of the third negative feedback regulator 111 is the difference between the voltage RMS value and the voltage RMS value reference. The input value of the third limiter 112 is the output value of the third negative feedback regulator 111, and the output value of the third limiter 112 is the output value of the first branch. The lower limit value of the limiting range of the third limiter 112 is greater than the upper limit value of the second limiter 132.

[0056] More specifically, the first negative feedback regulator 121, the second negative feedback regulator 131 and the third negative feedback regulator 111 are PI regulators, and the parameters of the first negative feedback regulator 121 and the second negative feedback regulator 131 are greater than the parameters of the third negative feedback regulator 111, so that the first negative feedback regulator 121 and the second negative feedback regulator 131 can respond to circuit changes more quickly.

[0057] More specifically, the voltage RMS loop 1 further includes a fourth limiter 14. The fourth limiter 14 limits the sum of the first branch output value, the second branch output value, and the third branch output value. The output value of the fourth limiter 14 is the output value of the voltage RMS loop, making the second branch output value more stable.

[0058] Optionally, the limiting range of the fourth limiter 14 is the same as the limiting range of the third limiter 112 .

[0059] Optionally, the limiting range of the first limiter 122 is [-0.5, 0], the limiting range of the second limiter 132 is [0, 0.5], and the limiting range of the third limiter 112 and the fourth limiter 14 is [0.85, 1.35].

[0060] In some embodiments, the voltage effective value reference may be obtained by a voltage effective value reference (RMS_REF) module 5 , and the voltage effective value may be obtained by a voltage effective value feedback calculation (RMS) module 6 and an effective value calculator 7 .

[0061] Specifically, the input value of the voltage RMS reference module 5 is the voltage RMS given value, and the output value is the voltage RMS reference. The voltage RMS feedback calculation module 6 obtains the voltage RMS according to the output value of the RMS calculator 7, and the input value of the RMS calculator 7 is the real-time inverter voltage value.

[0062] The real-time inverter loop 3 is used to control the real-time inverter voltage value to be closer to the target value.

[0063] See also Figure 2 In some embodiments, the real-time inverter loop 3 includes a duty cycle calculation branch 31 and a real-time voltage value feedback branch 32. The regulation signal is obtained based on the output value of the duty cycle calculation branch 31. The output value of the duty cycle calculation branch 31 is obtained based on the positive and negative bus voltage feedforward values, the real-time voltage value reference, and the output value of the real-time voltage value feedback branch 32 (the real-time voltage value feedback amount). The output value of the real-time voltage value feedback branch 32 is obtained based on the real-time inverter voltage value.

[0064] Specifically, the calculation formula of the voltage real-time value reference is:

[0065] Vinvref=(sinθ-IdcLoopOut)·Vrms_Ref·VrmsLoopOut;

[0066] Wherein, vienvref is the voltage real-time value reference, IdcLoopOut is the current DC component adjustment value, sinθ is the trigonometric function value, Vrms_Ref is the voltage RMS value reference, VrmsLoopOut is the output value of voltage RMS loop 1, and (sinθ-IdcLoopOut) is the inverter voltage phase.

[0067] More specifically, the phase-locked module 2 includes a phase-locked loop (PLL) 21 and a trigonometric function calculator 22. The phase-locked loop 21 obtains a phase-locked angle θ according to a given voltage effective value, and the trigonometric function calculator 22 obtains a trigonometric function value sinθ according to the phase-locked angle θ.

[0068] Specifically, the duty cycle calculation branch 31 includes a fourth negative feedback regulator 311 , and an input value of the fourth negative feedback regulator 311 is a difference between a voltage real-time value reference and an output value of the voltage real-time value feedback branch 32 .

[0069] The formula for calculating the output value of the duty cycle calculation branch 31 is:

[0070] P=(V+Vinref)·BueFeedBack;

[0071] Wherein, V is the output value of the fourth negative feedback regulator 311 , Vinref is the voltage real-time value reference, BueFeedBack is the positive and negative bus voltage feedforward value, and P is the output value (duty cycle) of the duty cycle calculation branch 31 .

[0072] Optionally, the fourth negative feedback regulator 311 is a KP negative feedback regulator.

[0073] The real-time inverter loop 3 further includes a PWM module 33 , which is configured to generate a regulating signal (PWM signal) according to the output value P of the duty cycle calculation branch 31 .

[0074] See also Figure 1 and Figure 2 Specifically, the regulation signal controls the opening and closing of the first switch Q11 / Q21 / Q31, the second switch Q12 / Q22 / Q32, the third switch Q13 / Q23 / Q33, and the fourth switch Q14 / Q24 / Q34, thereby controlling the real-time inverter voltage value. This is a technical means well known to those skilled in the art and will not be elaborated on herein.

[0075] See also Figure 1 and Figure 2The output signal of inverter 4 includes a real-time inverter voltage value and a real-time inverter current value. The voltage of the third capacitors C31 / C32 / C33 is the real-time inverter voltage value, which includes a DC component. This DC component can be obtained by filtering the real-time inverter voltage value using a filter. The current of inductors L1 / L2 / L3 can be measured to obtain a real-time inverter current value. This real-time inverter current value includes a DC component. This DC component can be obtained by filtering the real-time inverter current value using a filter.

[0076] The real-time inverter loop 3 is also used to control the DC component of the current and the DC component of the voltage to be closer to zero.

[0077] Specifically, the real-time inverter loop 31 further includes a first filter 34 and a fifth negative feedback regulator 35. The first filter 34 is used to filter the real-time inverter current value to obtain a current DC component, and the fifth negative feedback regulator 35 is used to obtain a current DC component adjustment value based on the current DC component.

[0078] Specifically, the real-time voltage value feedback branch 32 includes a second filter 321 and a sixth negative feedback regulator 322. The second filter 321 is used to obtain a voltage DC component from the real-time inverter voltage value, and the sixth negative feedback regulator 322 is used to obtain a voltage DC component adjustment value based on the voltage DC component. The output value of the real-time voltage value feedback branch 32 is the sum of the real-time inverter voltage value and the voltage DC component adjustment value.

[0079] Optionally, the fifth negative feedback regulator 35 and the sixth negative feedback regulator 322 are PI negative feedback regulators.

[0080] The above disclosure is only a preferred example of the present application and cannot be used to limit the scope of rights of the present application. Therefore, equivalent changes made according to the claims of the present application are all within the scope covered by the present application.

Claims

1. An inverter output control system, comprising a phase-locked module, a voltage RMS loop, and a real-time inversion loop; the phase-locked module is used to generate a trigonometric function value corresponding to a phase-locked angle according to a given voltage RMS value; the real-time inversion loop is used to output a regulation signal to the inverter according to the real-time inverter voltage value of the inverter, positive and negative bus voltage feedforward values, and a voltage real-time value reference; the voltage real-time value reference is obtained according to the product of the output value of the voltage RMS loop, the voltage RMS reference, and the inverter voltage phase; the voltage RMS reference is obtained based on the given voltage RMS value; the inverter voltage phase is obtained according to the trigonometric function value and a DC current regulation value obtained based on the real-time inverter current value output by the inverter; and characterized in that: The voltage effective value loop includes: a first loop branch, the first loop branch being configured to obtain a first branch output value according to a feedback voltage effective value and the voltage effective value reference, the voltage effective value being obtained according to the real-time inverter voltage value; a second loop branch, the second loop branch being configured to obtain a second branch output value according to a difference between the voltage effective value and the voltage effective value, wherein when the voltage effective value is greater than the sum of the voltage effective value reference and the voltage offset value, the second branch output value is a negative number, otherwise it is 0; a third loop branch, the third loop branch being configured to obtain a third branch output value according to a difference between the voltage effective value reference, the voltage effective value, and the voltage offset value, wherein when the voltage effective value is less than the difference between the voltage effective value reference and the voltage offset value, the third branch output value is a positive number, otherwise it is 0; The output value of the voltage effective value loop is obtained according to the sum of the first branch output value, the second branch output value and the third branch output value.

2. The inverter output control system according to claim 1, wherein: The second loop branch includes a first negative feedback regulator and a first limiter, and the third loop branch includes a second negative feedback regulator and a second limiter; The input value of the first negative feedback regulator is the sum of the voltage effective value reference and the voltage bias value minus the voltage effective value, and the input value of the second negative feedback regulator is the voltage effective value reference minus the voltage effective value and the voltage bias value; The input value of the first limiter is the output value of the first negative feedback regulator, and the output value of the first limiter is the output value of the second branch; The input value of the second limiter is the output value of the second negative feedback regulator, and the output value of the second limiter is the output value of the third branch; The limiting range of the first limiter is less than or equal to 0, and the limiting range of the second limiter is greater than or equal to 0.

3. The inverter output control system according to claim 2, wherein: The first loop branch includes a third negative feedback regulator and a third limiter; The input value of the third negative feedback regulator is the difference between the voltage effective value and the voltage effective value reference; The input value of the third limiter is the output value of the third negative feedback regulator, and the output value of the third limiter is the first branch output value; The lower limit value of the limiting range of the third limiter is greater than the upper limit value of the second limiter.

4. The inverter output control system according to claim 3, wherein: The first negative feedback regulator, the second negative feedback regulator and the third negative feedback regulator are PI regulators, and the parameters of the first negative feedback regulator and the second negative feedback regulator are greater than the parameters of the third negative feedback regulator.

5. The inverter output control system according to claim 3, wherein: The voltage effective value loop further includes a fourth limiter; The fourth limiter limits the sum of the first branch output value, the second branch output value and the third branch output value, and the output value of the fourth limiter is the output value of the voltage effective value loop; The limiting range of the fourth limiter is the same as the limiting range of the third limiter.

6. The inverter output control system according to claim 1, wherein: The real-time inversion loop includes a duty cycle calculation branch and a voltage real-time value feedback branch; The regulating signal is obtained according to the output value of the duty cycle calculation branch, the output value of the duty cycle calculation branch is obtained based on the positive and negative bus voltage feedforward values, the voltage real-time value reference and the output value of the voltage real-time value feedback branch, and the output value of the voltage real-time value feedback branch is obtained based on the real-time inverter voltage value.

7. The inverter output control system according to claim 6, wherein: The calculation formula of the voltage real-time value reference is: Vinvref=(sinθ-IdcLoopOut)·Vrms_Ref·VrmsLoopOut; Among them, Vinvref is the voltage real-time value reference, IdcLoopOut is the DC current adjustment value, sinθ is the trigonometric function value, Vrms_Ref is the voltage RMS reference, VrmsLoopOut is the output value of the voltage RMS loop, and (sinθ-IdcLoopOut) is the inverter voltage phase.

8. The inverter output control system according to claim 6, wherein: The duty cycle calculation branch includes a fourth negative feedback regulator, and the input value of the fourth negative feedback regulator is the difference between the voltage real-time value reference and the output value of the voltage real-time value feedback branch; The formula for calculating the output value of the duty cycle calculation branch is: P=(V+Vinref)·BusFeedBack; Wherein, V is the output value of the fourth negative feedback regulator, Vinref is the voltage real-time value reference, BusFeedBack is the positive and negative bus voltage feedforward value, and P is the output value of the duty cycle calculation branch; The real-time inverter loop further includes a PWM module, which is configured to generate the regulating signal according to the output value P of the duty cycle calculation branch.

9. The inverter output control system according to claim 6, wherein: The real-time inversion loop further includes a first filter and a fifth negative feedback regulator; The first filter is used to filter the real-time inverter current value to obtain a current DC component; The fifth negative feedback regulator is used to obtain the DC current adjustment value according to the DC current component.

10. The inverter output control system according to claim 6, wherein: The voltage real-time value feedback branch includes a second filter and a sixth negative feedback regulator; The second filter is used to obtain a voltage DC component from the real-time inverter voltage value; The sixth negative feedback regulator is used to obtain a voltage DC component adjustment value according to the voltage DC component; The output value of the voltage real-time value feedback branch is the sum of the real-time inverter voltage value and the voltage DC component adjustment value.

Images