High resolution input apparatus, frequency transformer system having the apparatus and processing method for analogue input voltage signal

Abstract

The invention provides a high-resolution input device and a frequency converter system with the high-resolution input device, wherein, the frequency converter system comprises a voltage polarity judgment unit used for judging the polarity of analog input voltages; a precise full-wave rectification unit used for converting the analog input voltage signal into an absolute value signal; a voltage benchmark comparison unit used for receiving the absolute value signal and comparing the absolute value signal with at least a voltage critical value so as to judge the voltage range of the absolute value signal; a DC compensation control unit used for adjusting the DC compensation quantity of the absolute value signal according to the voltage range of the absolute value signal; an in-phase addition unit used for receiving the absolute value signal and the DC compensation quantity and gaining a digital counting result by A / D conversion after DC compensating the absolute value signal and fixedly amplifying the gain; and a micro-controller used for inversely calculating the analog input voltage according to a polarity signal, the voltage range of the absolute value signal and the digital counting result. Meanwhile, the invention discloses a method for processing the analog input voltage signal of the frequency converter system.

Description

technical field [0001] The invention relates to the technical field of frequency converters, in particular to a high-resolution input device, a frequency converter system with the device and a processing method for analog input voltage signals. Background technique [0002] The frequency converter is a power conversion device that converts the AC power supply with fixed frequency and voltage into DC power after rectification, and then converts the DC power into AC power supply with variable voltage and frequency. The inverter can convert DC power into AC power, so the inverter is widely used in applications such as solar power generation systems, electric vehicles and uninterruptible power systems; because the inverter can change the voltage / frequency (V / f) at the same time to change the motor Therefore, inverters are widely used in applications such as refrigeration and air conditioning, high-speed rail, and MRT to achieve variable speed or increase the efficiency of motors...

AI Technical Summary

Problems solved by technology

It can be seen that the calculation error of the MCU itself is amplified due to the fixed proportional gain (P=0.25<1). Considering the maximum measurement error, the measurement error value is 0.07V. When the external analog input voltage is accurate The lower the level, the higher the measurement error rate. In other words, the lower the external analog input voltage level, the lower the accuracy of MCU detection; therefore, it is impossible to achieve precise control when the external analog input voltage level is low.

[0012] Referring to Table 1 below, it can be seen more clearly that due to the maximum measurement error value and fixed proportional gain of A-D conversion, the MCU judgment accuracy will deteriorate with the decrease of the analog input voltage value

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