Figure 1.

Main circuit of thirteen-level inverter"

Figure 2.

The working state of the inverter at different output levels in the positive half cycle (a)0+(b)0- (c)Vdc(d)2Vdc (e)3Vdc(f)4Vdc (g)5Vdc(h)6Vdc"

Table 1.

Charging and dischargings tate of capacitor in different switching modes"

Figure 3.

Topological expansion of inverter topology"

Figure 4.

The modulation principle diagram of inverter (a)Carrier and modulation waveform (b)Original PWM waveform (c)The control signal waveform of each switch (d)Target output waveform"

Table 2.

Equivalent parameters in the six working modes"

Table 3.

Comparison of seven thirteen-level switched capacitor inverters"

Figure 5.

The structure of inverter closed-loopcontrol system"

Figure 6.

Output voltage and current waveform of inverter"

Figure 7.

The simulated voltage and current waveforms when the power changes after filtering"

Table 4.

Component parameters of experimental prototype"

Figure 8.

Experimental waveform of switch tubedriving signal (a)S1,S2,S3,S4 (b)S5,S6,S7,S8 (c)S9,S10,S11,S12 (d)S13,S14"

Figure 9.

Thirteen-level voltage and current waveforms ofinverter output"

Figure 10.

Dynamic waveform of output frequencychange experiment (a)Output frequency changes from 50 Hz to 100 Hz (b)Output frequency changes from 100 Hz to 50 Hz"

Figure 11.

Output voltage waveform of inverter after filtering"

Figure 12.

The physical voltage and current waveforms when the power changes after filtering"

Figure 13.

Efficiency at different power"