Dead zone compensation method for H-bridge topology

Abstract

The invention discloses a dead zone compensation method for H-bridge topology. With the method adopted, the influence of odd-order harmonics brought by dead zone control can be decreased when the deadzone control is carried out, and output quality is improved. The method includes the following steps that: A, all working modes of an H-bridge topology circuit in corresponding modulation modes are analyzed; B, the average error voltage of the H-bridge topology circuit in each working mode is calculated; C, the current working mode of the H-bridge topology circuit is judged; D, an average error voltage corresponding to the current working mode of the H-bridge topology circuit which is judged in the step C is selected from the average error voltages calculated in the step B; and E, the averageerror voltage selected in the step D is converted to a PWM duty cycle compensation amount, and the PWM duty cycle compensation amount is superimposed on the original PWM duty cycle reference of the current H-bridge topology circuit.

Description

technical field [0001] The invention relates to the field of grid-connected inverters, and in particular relates to a dead-zone compensation method of an H-bridge topology. Background technique [0002] In the current power conversion and power drive industries, the H-bridge topology grid-connected inverter is widely used as a classic topology. Among them, the H-bridge topology includes classic H4 bridge, H5 bridge, multi-level H bridge and so on. For example, H5 bridge topology grid-connected inverter, such as figure 1 As shown, the main circuit is driven by unipolar SPWM, figure 1 in, V bus is the DC bus voltage; T 1 to T 5 It is the switching tube of H5 topology; VD 1 to VD 5 Respectively are the parasitic diode of the switching tube; V ab The output voltage of the main circuit. To allow the exchange of reactive components, figure 1 The drive waveform of the H5 bridge topology grid-connected inverter is shown as figure 2 As shown, the following three principle...

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Problems solved by technology

[0012] In addition to the fundamental wave error of the output voltage, this error voltage also generates odd harmonics. Therefore, when the PWM control is used, the dead zone control is added. Although the problem of direct damage to the power switch tube of the same bridge arm is solved, it is also Bring in the fundamental wave error of the output voltage, generate odd harmonics of the current, and affect the output quality of the circuit

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