Development And Improvement Of Intelligent Capacitance Measurement Device Based On MSP430

Reactive power compensation equipment play an important role in power system. Because of long-term switched, the electrical capacitor is bound to aging. In view of this situation, a Intelligent capacitor measuring device, can check it periodically In this paper, Intelligent capacitor measuring device is composed of two parts: the handheld device and power source. My work is mainly research and development of the power source, so this paper is based on the main line power source as main line to start. In this paper, the power source can output maximum power at 100W, the maximum voltage can reach 90V, the maximum output frequency can reach 200Hz. In my paper,advanced direct digital synthesizer chip (DDS) AD9851 systems is the chip signal generator,it's filter circuit is using the form of a second-order low-pass filter circuit and the first-order high-pass filter circuit in series, it can filter High-frequency noise and DC component effectively. Regardless of the signal output being 3V or 9V the 20Hz signal's Amplitude can reach accuracy of 0.02%, the difficulty of the system is that the 200Hz output signal's can't reach accuracy of 0.1%. and that there is a serious problem of attenuation.In view of this problem, this paper introduces the voltage loop control strategy, the control strategy can solve the serious attenuation problem of signal's amplitude at 200Hz. 16-bit DA-chip can control the gain of output voltage. Through the analog multiplier of the sine wave can be modulated, we can achieve the control of amplitude of sine wave. In order to achieve the characteristics of voltage source, the use of closed-loop control of voltage link the idea of closed-loop control by the MCU and analog circuits to achieve. In this paper, most of the work is under 200Hz in order to ensure stable output signal amplitude. 200Hz in order to ensure the stability of the output voltage of the system voltage control in the hardware aspects of experimental design and spent a great deal of time and effort. Voltage loop is extremely difficult to choose the hardware, because, taking into account the accuracy of the output signal power to achieve 0.1% accuracy, the accuracy of all aspects of the hardware have to be better than 0.1%, or less than the power signal on the requirements of Specifications...