隨著光伏發電系統快速發展,以及電動汽車充電樁的普及,傳統的剩余電流保護器無法滿足實際需求。介紹了一款B型剩余電流保護器,采用磁調制剩余電流互感器和零序電流互感器采集剩余電流。根據GB/T 22794—2017標準要求,可識別1 kHz及以下的正弦交流、帶和不帶直流分量的脈動直流、平滑直流等剩余電流信號。經信號調理電路將電壓信號送到單片機進行采集和判斷。通過試驗測試,該樣機在測試精度和速度上均符合國家標準的相關要求。The rapid development of photovoltaic power generation systems and the popularity of electric vehicle charging piles make the traditional residual current protective devices unable to meet the actual demand.This paper proposed a type B residual current protective device,which uses the magnetically modulated residual current transformer and the zero sequence current transformer to acquire the residual current.According to the requirements of GB/T 22794—2017,the type B residual current protective device can detect sinusoidal AC residual current of 1kHz and below 1kHz,pulsating DC residual current with and without DC component,smooth DC residual current and so on.The signal processing circuit sends the voltage signal to the MCU for acquisition and judgment.Through experimental tests,the device meets the relevant requirements of national standards in terms of test accuracy and speed.
標簽： 電流保護器
上傳時間： 2022-03-27
上傳用戶：
電學中的測量技術涉及范圍非常廣,電流測量在電學計量中占有非常重要的位置。如何精確地進行電流測量是精密測量的一大難題。傳統的電流檢測電路多采用運算放大芯片與片外電流檢測電路相結合的方式,電路集成度很低,需要較多的接口和資源才能完成對電路的檢測。本文把所有電路部分都集成在一塊芯片上,包括檢測電阻,運算放大器電路及模擬轉數字轉換電路,從而在電路內部可以進行電流檢測,使電路更好的集成化。前置電路使用二級共源共柵結構的運算放大器,減小溝道長度調制效應造成的電流誤差。10位SAR ADC中采用電容驅動能力強的傳輸門保證了模數轉化器的有效精度。比較器模塊采用再生鎖存器與遲滯比較器作為基礎單元組合解決精密測量的問題。本設計可以作為嵌入芯片內的一小部分而檢測芯片中的微小電流1mA~100mA,工作電壓在1.8v左右,電流檢測精度預期達到10uA的需求。The measurement technology in electricity involves a wide range,and current measurement plays a very important position in electrical measurement.How to accurately measure current is a big problem in precision measurement. The traditional current detecting circuit adopts the combination of the operational amplifier chip and theoff-chip current detecting circuit, The circuit integration is very low, and more interfaces and resources are needed tocomplete the circuit detection.This topic integrates all the circuit parts into one chip, including detection resistance, operational amplifier circuit andanalog to digital conversion circuit. Highly integrated circuit makes the external resources on the chip more intensive,so that current detection can be carried out inside the circuit, so that the circuit can be better integrated. Thefront-end circuit of this project uses two-stage cascade operational amplifier and cascade tube to reduce the currenterror caused by channel length modulation effect. In 10-bit SAR ADC, the transmission gate with strong capacitivedriving ability ensures the effective accuracy of the analog-to-digital converter. Comparator module uses regenerativelatch and hysteresis comparator as basic unit to solve the difficult problem of precision measurement. This topic can beused as a small part of the embedded chip to detect the micro-current in the chip 1 mA~100 mA, the working voltageis about 1.8v, and the current detection accuracy is expected to reach the requirement of 10 uA.
上傳時間： 2022-04-03
上傳用戶：
系統簡介:1.單片機+LCD1602液晶顯示器+三極管放大電路+蜂鳴器+按鍵+DS18B20+GSM遠程報警等設計。2. 3個按鍵對應3個不同的功能，設定值加1、設定值減1和蜂鳴器檢測。3. 5V可使用USB供電。4. DS18B20溫度傳感器模塊實現對溫度的檢測。測量范圍-50~120攝氏度，常溫LCD1602顯示25.0攝氏度左右，溫度精度在0.1℃；誤差±0.2℃以內.溫度變化時，顯示值將變化。蜂鳴器就會報警。啟動GSM短信報警功能。默認設定值31攝氏度（方便用人體模擬）。5.采用三極管進行輸出放大,驅動能力強、蜂鳴器顯示效果更好!6. 特點：穩定、操作起來非常方便，上電就可以使用。7.佩戴引出I/O接口(40個排針)，用于連接下載器下載程序, 方便進行升級調試.操作說明:S0:復位鍵 S1:設定值加1 S2：設定值減1 S3：蜂鳴器檢測 1、 上電/S0復位：液晶顯示“detect System” “Temp=25.0 32.0” ，對應檢測溫度和設定報警溫度。檢測傳感器表面溫度，顯示值變化。2、按S1、S2鍵：可以實現設定溫度的加減操作。3、按S3鍵：檢測蜂鳴器響聲。4、可以用手抓住溫度傳感器，模擬溫度檢測。檢測到溫度變化后、液晶顯示值變化，當檢測溫度大于設定溫度時，蜂鳴器就會報警。并發送“DS18B20 Warning!”信息到指定手機。5、發送短信時，第一行顯示將發送變化：“message sending” “the sending ok” 6、手機卡記得插到卡槽里噢
上傳時間： 2022-06-09
上傳用戶：
