SVPWM (Space Vector Pulse Width Modulation) synchronous modulation/overmodulation method of high-power AC transmission system

An AC drive, synchronous modulation technology, applied in the direction of AC motor control, control system, electrical components, etc., can solve the problems of harmonic distortion, limitation, unsuitable for high-power inverter occasions, etc., to reduce harmonics, the method is simple workable effect
CN106301149AInactive Publication Date: 2017-01-04DALIAN UNIV OF TECH
2 Cites 8 Cited by

Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
DALIAN UNIV OF TECH
Publication Date
2017-01-04
Estimated Expiration
Not applicable · inactive patent

Smart Images

  • Figure 1
    Figure 1
  • Figure 2
    Figure 2
  • Figure 3
    Figure 3
Patent Text Reader

Abstract

The invention provides a SVPWM (Space Vector Pulse Width Modulation) synchronous modulation / overmodulation method of a high-power AC transmission system. The SVPWM synchronous modulation / overmodulation method comprises the following steps of dividing a modulation region to a linear modulation region, an overmodulation region I and an overmodulation region II according to a modulation ratio; calculating a first modulation ratio corresponding to a boundary of the linear modulation region and the overmodulation region I, a second modulation ratio corresponding to a boundary of the overmodulation region I and the overmodulation region II and maximum modulation ratio corresponding to an upper limit of the overmodulation region II by using a basic bus clamping strategy according to number and positions of sampling points in a fan-shaped region; determining a modulation coefficient according to the modulation ratios, determining a weighting coefficient of synthesis compensation voltage vector according to the modulation coefficient, and synthesizing compensation voltage vectors of the overmodulation region I and the overmodulation region II; and calculating action time of two effective voltage vectors and a zero vector required by the synthesis compensation voltage vector for PWM (Pulse Width Modulation) by using a volt-second balance pricinple. By the SVPWM synchronous modulation / overmodulation method, a high-power inverter can be smoothly transitioned to a six-beat wave working state from linear modulation.
Need to check novelty before this filing date? Find Prior Art

Description

technical field

[0001] The invention relates to the field of high-power AC drive control, in particular to a SVPWM synchronous modulation and over-modulation method for a high-power AC drive system. Background technique

[0002] Medium and high voltage high-power inverters based on high-power power electronic switching devices have been widely used in metal rolling, mine hoisting, ship propulsion, locomotive traction and other fields. However, when power electronic switching devices work under high voltage and high current conditions, switching loss and device heat dissipation cannot be ignored, and the highest allowed switching frequency is usually less than 1kHz. At such a low switching frequency, a synchronous modulation strategy is usually used to maintain a high degree of symmetry in the output PWM waveform, thereby effectively reducing harmonics.

[0003] When the bus voltage on the DC side of the inverter decreases or the AC drive system enters the field-weakening re...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More