A static var generator anti-interference controller and its design method

Abstract

The invention discloses a static var generator anti-interference controller and a design method thereof. The controller includes an input unit, a coordinate transformation unit, a DC voltage adjustment module, a disturbance observation unit 1, a disturbance observation unit 2, a power factor Regulating module, disturbance observation unit 3 and SVPWM unit. The disturbance observer used in the present invention regards the difference between the actual object and the ideal model caused by external disturbance and system parameter changes as equivalent control input, observes the equivalent disturbance, and adds an equal amount of compensation to the control to realize suppression of interference. The invention regards all parameters except state variables as uncertain items, and estimates them with a disturbance observer. The structural model is simplified, the design idea of ​​the controller is clear, the control method is simplified, and it is easy to implement. The present invention adopts the idea of ​​backstepping, designs the control scheme step by step, and structures the design process of the controller.

Description

technical field [0001] The invention relates to a direct current control method for a static var generator, in particular to a static var generator anti-interference controller and a design method thereof. Background technique [0002] The static var generator is a new type of reactive power compensation device based on a self-commutated converter circuit. The static var generator based on a rectifier (PWM rectifier) ​​topology combined with pulse width modulation technology is connected to the grid through a reactor. The rectifier A capacitor is added on the DC side to stabilize the DC side voltage and exchange energy with the grid. Adopt appropriate control strategies to control the amplitude and phase of the AC side voltage of the rectifier by controlling the on-off of the switch tube, or use direct current control to control the output current of the rectifier so that the static var generator emits or absorbs the grid current. The reactive component realizes the purpose...

AI Technical Summary

Problems solved by technology

However, this method requires a higher switching frequency, so it has higher requirements for switching elements; the hysteresis PWM control method can improve the response speed of the current, and the dynamic tracking effect is good, but it has higher requirements for the grid-side inductance, and the switching loss is also obvious. increase

[0004] In summary, in the research on the control of static var generators, in terms of controller design and control effects, the existing technology has the following deficiencies: First, the existing static var generator control methods are dependent on system parameters Strong, the control effect is obviously affected by the parameters

Second, some existing control methods have high requirements on the switching elements of the static var generator, which greatly increases the cost of reactive power compensation

Third, in order to achieve the ideal control effect, more than two control algorithms are used for composite control, and the designed controller is more complicated, which increases the difficulty of implementation

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