低頻數字式相位測量儀

測控論文編號:CK137   論文字數:11601,頁數:31 附外文翻譯

目錄
摘要
Abstract 
目錄
1  前 言…...  1
2  總體方案設計 2
2.1設計要求 2
2.2方案比較 3
2.2.1相位測量方案 3
2.2.2 移相網絡方案 4
2.2.3顯示界面方案 5
2.2.4 總體設計方案 5
3 系統設計 6
3.1總體框圖 6
3.2相位測量部分 6
3.2.1波形轉換、整形放大 8
3.2.2鎖相環倍頻 9
3.2.3閘門電路 11
3.2.4控制門 11
3.2.5計數器 11
3.2.6鎖存器 11
3.2.7  顯示譯碼器與數碼管 12
3.3頻率測量部分 12
3.3.1數字頻率計的基本原理 12
3.3.2系統框圖 12
3.4 移相網絡 14
4 系統設計細節化 16
4.1  LM324運放電路 16
4.2相位鎖定環路 PLL 17
4.3放大整形電路 18
4.4  1秒的時基信號發生器 18
4.5計數、譯碼、顯示部分 19
4.6電源電路的設計 19
5 系統措施分析 21
5.1改善穩壓器工作穩定性和瞬變響應的措施 21
5.2 確保不毀壞器件的措施 21
5.3穩壓器輸入電壓值的確定 22
6  總 結 23
致 謝 24
參考文獻 25
附件 26

摘  要

 本設計實現了一個低頻相位測量系統，包括相位測量儀、數字式移相信號發生器和移相網絡三部分。
 移相網絡主要是由RC移相電路和LM324運放電路組成，將被測信號送入移相網絡，經RC移相、LM324隔離放大，產生兩路信號，一路為基準信號經過波形轉換，另一路為移相后的信號。分別經過波形轉換、整形、二分頻送給相位測量模塊及頻率測量模塊。
 相位差測量儀主要是由鎖相環PLL（Phase Lock Loop）產生360倍頻基準信號和移相網絡的基準信號與待測信號進行異或后的信號作為顯示器的閘門電路和控制信號。
 頻率測量模塊主要是用計數法測量頻率的，它是有某個已知標準時間間隔Ts內，測出被測信號重復出現的次數N，然后計算出頻率f=N/Ts。
 顯示電路模塊主要是由計數器、鎖存器、譯碼器和數碼管組成。
 對于低頻相位的測量，用傳統的模擬指針式儀表顯然不能夠滿足所需的精度要求，隨著電子技術以及微機技術的發展，數字式儀表因其高精度的測量分辨率以及高度的智能化、直觀化的特點得到越來越廣泛的應用。同頻率正弦信號間的相位差測量在電工技術、工業自動化、智能控制及通訊、電子等許多領域都有著廣泛的應用，如電工領域中的電機功角測試，介質材料損耗角的確定等。因此，相位差測量技術有著廣泛的實用價值。

關鍵詞：相位測量；頻率測量；低頻；PLL

Abstract

 This design has realized a low-frequency phase measuring system, including three parts: phase measuring apparatus, digital phase excursion signal generator and phase excursion network.
 Phase-shifting network mainly by the RC phase shifter circuit and LM324 op amp circuit, will the measured signal into the phase-shifting network, by the RC phase shifter, LM324 enlarge isolation, resulting in two signals, all the way through wave-based signal conversion, another way for the phase-shifted signal. Waveform, respectively, after conversion, shaping ,second sub-frequency to the phase measurement and frequency measurement module.
 Phase difference measurement is the main phase-locked loop PLL (Phase Lock Loop) frequency reference signal 360 generated and phase-shifting network of reference signal varies with the test signal or after the display of the signal as the gate circuit and control signals.
 Frequency measurement module is measured by counting the frequency, which is a known time interval Ts, the measured signal to detect the number of repeated N, and then calculated the frequency of f = N / Ts.
 Display circuit modules mainly by the counter, latch, decoder and digital tubes.
 For low-frequency phase measurements, using traditional analog pointer instrument is clearly not able to meet the required accuracy, with the electronic technology and computer technology, digital high-precision measurement instrumentation for its resolution and a high degree of intelligence, visual characteristics of a wide range of applications has been increasing. Sinusoidal signal with frequency between the phase difference measurement in electrical technology, industrial automation, intelligent control and communications, electronics and many other fields have a wide range of applications, such as electricians in the field of electric power angle test, dielectric materials, such as the determination of loss angle. Therefore, the phase measurement techniques have a wide range of practical value. 
Keywords：Phase Measurement；Frequency Measurement；Low- Frequency ；PLL