Three-phase two-level inverter current ripple minimum effective value PWM method and system
A current ripple and inverter technology, applied in the field of three-phase two-level inverter current ripple minimum effective value PWM method and system, can solve the problem of low harmonic distortion rate, increase current ripple, torque Low pulsation and other issues to achieve the effect of reducing loss and improving current quality
Image
Examples
Embodiment 1
[0077] In order to describe the technical solution of this application in more detail, the current ripple RMS prediction model is described in the actual three-phase two-level inverter system, specifically:
[0078] The topology of the three-phase two-level inverter is as follows figure 1 shown. There are 6 semiconductor switches in the three-phase bridge arms. Each phase bridge arm can only be turned up and down or down and turned on and off. The switching pulses corresponding to this phase are high level (1) and low level (0). When the upper bridge arm is turned on and the lower bridge arm is turned off, the bridge arm ends (points a, b, and c) are connected to the positive pole of the DC bus voltage Vdc / 2, otherwise they are connected to the negative pole -Vdc / 2. The load terminal is replaced by a three-phase symmetrical voltage source, and the current ripple is generated due to the instantaneous voltage difference between the two ends of the inductor.
[0079] Its curren...
Embodiment 2
[0104] More specifically, on the basis of Example 1, such as image 3 As shown, the present invention proposes a three-phase two-level inverter current ripple minimum effective value PWM method, comprising the following steps:
[0105]S1: Perform scaling calculation and coordinate transformation processing on the voltage vector and electrical angle of the modulated given amount to obtain the three-phase desired phase voltage;
[0106] S2: Calculate the zero vector distribution factor according to the three-phase expected phase voltage;
[0107] S3: Calculate the three-phase modulation signal according to the zero vector distribution factor;
[0108] S4: Obtain the switching period, and generate the final output pulse on the basis of the three-phase modulation signal.
[0109] In the specific implementation process, the calculation method in step S2 is based on the current ripple RMS prediction model, which establishes a given voltage vector relationship between the current r...
Embodiment 3
[0138] More specifically, on the basis of Example 2, as Figure 4 As shown, a three-phase two-level inverter current ripple minimum effective value PWM system is provided, including a coordinate transformation module, a zero-vector distribution calculation module, a modulation signal calculation module and a pulse generation module; wherein:
[0139] The coordinate transformation module performs scaling calculation and coordinate transformation processing for the input voltage vector and electrical angle, and generates a three-phase desired phase voltage;
[0140] The zero vector distribution calculation module is based on the current ripple RMS prediction model; with the minimum current ripple RMS as the goal, the zero vector distribution factor is calculated and obtained;
[0141] The modulated signal calculation module is used to calculate the three-phase modulated signal according to the zero vector distribution factor;
[0142] The pulse generating module is used for gen...
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Description
Claims
Application Information
- IPC
- H02M7/5395; H02M7/483; H02M1/12; H02M1/14
- Inventors
- 谈启伦