An Orthogonal Signal Generator System Based on Adaptive Least Mean Square Algorithm

Abstract

The invention relates to a quadrature signal generator system based on a self-adaptive least mean square algorithm. The system is technically characterized by comprising a self-adaptive band-pass filter and a quadrature signal generator, the self-adaptive band-pass filter and the quadrature signal generator are connected with each other, and the quadrature signal generator comprises a multiplier, an integrator and an amplifier which are connected with each other; a closed-loop transfer function of the self-adaptive system of the self-adaptive band-pass filter is as shown in the description, wherein s=j<omega>, k=<mu> / Ts; a closed-loop transfer function of the quadrature signal generator is as shown in the description. The system can generate the required quadrature signal and also can eliminate the influence from DC bias component to phase-locked loop performance, and the composition is easy to realize discretization.

Description

technical field [0001] The invention relates to the technical field of network voltage phase information extraction based on a phase-locked loop method of a synchronous reference coordinate system, in particular to an orthogonal signal generator system based on an adaptive least mean square algorithm. Background technique [0002] The grid synchronization of single-phase grid-connected inverters depends on the accurate detection of grid voltage phase information, and the accuracy of phase information has an important impact on the power quality, stability and reliability of single-phase grid-connected systems. Synchronous reference frame phase-locked loop method is widely used in the extraction of grid voltage phase information. The structure of a general synchronous reference frame-PLL (synchronous reference frame-PLL) includes three basic modules: a phase angle detector, a loop filter and a voltage-controlled oscillator. In practical applications, it is often necessary fo...

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Problems solved by technology

The measurement and sampling of grid voltage needs to go through three links: voltage sensor, low-pass filter, and A / D converter. The nonlinearity of the voltage sensor, the temperature drift of analog components and the nonlinearity of the A / D converter will bias the DC The component is introduced into the grid voltage input signal. After the static / rotating coordinate transformation, the corresponding fundamental frequency AC component will be generated in the q-axis, which will affect the steady-state accuracy of the PLL. If it is eliminated by reducing the bandwidth, it will affect the dynamic performance of the PLL.

However, there are few studies on the influence of the DC bias component in the grid voltage input signal on the phase observation.

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