Device for detecting effective value of alternating voltage at high speed
By designing a high-speed detection device including a full-wave rectifier bridge and a linear optocoupler, the problem of excessively long response time of traditional voltage detection is solved, and rapid detection and accurate calculation of the effective value of the AC voltage is achieved.
Patent Information
- Application Number
- CN202420510673.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-03-16
- Publication Date
- 2025-03-04
- Estimated Expiration
- 2034-03-16
AI Technical Summary
Traditional voltage transmitters have a long response time when detecting the valid AC voltage value and cannot meet the needs of some application scenarios.
A high-speed detection device including a full-wave rectifier bridge and a linear optocoupler is designed. It reduces the current through the current limiting resistor and is rectified into a pulsating DC current, and isolates it by a linear optocoupler and converts it into a voltage quantity. The instantaneous value of every 1 millisecond is accumulated and averaged by PLC to obtain the effective value of the AC voltage.
The corresponding speed of voltage detection is significantly improved, and instantaneous values can be detected and accumulated within 1 millisecond, ensuring that accurate AC voltage effective values are obtained within 20 milliseconds.
Smart Images
Figure CN222561683U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of voltage detection, in particular to a device for high-speed detection of effective value of alternating current voltage. Background Art
[0002] The effective value detection response time of traditional voltage transmitters is generally around 200ms, which cannot meet application requirements in some application scenarios. Utility Model Content
[0003] In view of the above technical problems, the utility model provides a device for high-speed detection of the effective value of an AC voltage, which is used to solve the problem that the voltage detection response speed of a traditional voltage detection device is slow.
[0004] In order to achieve the above purpose, the technical solution of the utility model is as follows:
[0005] A device for high-speed detection of the effective value of an alternating current voltage comprises a full-wave rectifier bridge and a linear optocoupler, wherein the input end of the full-wave rectifier bridge is connected to the L end of the alternating current voltage to be measured through a current limiting resistor, the other input end of the full-wave rectifier bridge circuit is connected to the N end of the alternating current voltage to be measured, the + pole of the DC output end of the full-wave rectifier bridge is connected to the anode of the light-emitting diode at the input end of the linear optocoupler, the - pole of the DC output end of the full-wave rectifier bridge is connected to the cathode of the light-emitting diode at the input end of the linear optocoupler, a current-to-voltage resistor is connected to two output ends of the linear optocoupler, and both ends of the current-to-voltage resistor are connected to the analog input end of a programmable controller.
[0006] Compared with the prior art, the beneficial effect of the utility model is that the device rectifies the AC voltage into a pulsating DC current after reducing the voltage through a resistor and limiting the current, and then isolates the DC current through a linear optocoupler, and converts the current into a voltage in a linear proportion, and detects it through a PLC, and accumulates the instantaneous value every 1 millisecond, accumulates the AC quantity for one cycle, and then calculates the average value of the accumulated value of one cycle, that is, the effective value of the AC voltage is obtained, which greatly improves the detection response speed of the voltage. BRIEF DESCRIPTION OF THE DRAWINGS
[0007] Figure 1 It is the circuit principle diagram of the utility model; Description of the drawings:
[0009] 1. Current limiting resistor; 2. Full-wave rectifier bridge; 3. Linear optocoupler; 4. Current-to-voltage resistor; 5. Programmable controller. DETAILED DESCRIPTION
[0010] In order to make the purpose, technical solution and advantages of the utility model clearer, the utility model is further described in detail below in combination with specific implementation methods and with reference to the accompanying drawings. It should be understood that these descriptions are only exemplary and are not intended to limit the scope of the utility model. In addition, in the following description, the description of well-known structures and technologies is omitted to avoid unnecessary confusion of the concept of the utility model.
[0011] A device for high-speed detection of the effective value of an AC voltage comprises a full-wave rectifier bridge 2 and a linear optocoupler 3, wherein the input end of the full-wave rectifier bridge 2 is connected to the L end of the AC voltage to be measured through a current limiting resistor 1, and the other input end of the full-wave rectifier bridge 2 circuit is connected to the N end of the AC voltage to be measured, the + pole of the DC output end of the full-wave rectifier bridge 2 is connected to the anode of the light-emitting diode at the input end of the linear optocoupler 3, the - pole of the DC output end of the full-wave rectifier bridge 2 is connected to the cathode of the light-emitting diode at the input end of the linear optocoupler 3, and the current-to-voltage resistor 4 is connected to the two output ends of the linear optocoupler 3, and the current is converted into a voltage at the same time. The two ends of the measuring resistor 4 are connected to the analog input end of the programmable controller 5. The device reduces the voltage of the AC voltage through the resistor and limits the current, and at the same time rectifies it into a pulsating DC current. The DC current is then isolated through the linear optocoupler 3 and converted into a current in a linear proportion, which is converted into a voltage at both ends of the parallel resistor. The voltage varying between 0-5V is detected by the PLC analog detection, and then the PLC accumulates the instantaneous value of each 1 millisecond, accumulates the detected AC quantity for one cycle, and then averages the accumulated value of one cycle to obtain the effective value of the AC voltage.
[0012] Working principle:
[0013] At the L and N ends of the device being measured, when the amplitude of the alternating voltage changes, the loop current also changes in linear proportion due to the series current limiting resistor 1, and is simultaneously converted into a pulsating DC current through the full-wave rectifier bridge 2 and flows into the input end of the linear optocoupler 3, so that an equal amount of DC current is output at the output end of the linear optocoupler 3 and applied to both ends of the current-to-voltage resistor 4. The voltage across the current-to-voltage resistor 4 is connected to the analog input end of the programmable controller 5; the programmable controller 5 detects and accumulates this analog quantity once every 1ms through a logic control program. Assuming that the detected voltage analog quantity is known to be an industrial frequency of 50HZ, its change cycle is 20ms, then the program will accumulate and calculate the analog value detected 20 times, and divide this value by 20 to obtain the average value, and at the same time, the current analog quantity ratio coefficient is obtained according to the series-parallel resistance of the circuit, and the average value obtained is multiplied by the analog quantity ratio coefficient, that is, the effective value of the measured industrial frequency voltage is obtained within 20ms.
[0014] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.
Claims
1. A device for high-speed detection of effective value of AC voltage, characterized in that: The invention comprises a full-wave rectifier bridge (2) and a linear optocoupler (3), wherein the input end of the full-wave rectifier bridge (2) is connected to the L end of the AC voltage to be measured through a current limiting resistor (1), and the other input end of the full-wave rectifier bridge (2) circuit is connected to the N end of the AC voltage to be measured, the + pole of the DC output end of the full-wave rectifier bridge (2) is connected to the anode of the light-emitting diode at the input end of the linear optocoupler (3), and the - pole of the DC output end of the full-wave rectifier bridge (2) is connected to the cathode of the light-emitting diode at the input end of the linear optocoupler (3), and a current-to-voltage resistor (4) is connected to both output ends of the linear optocoupler (3), and at the same time, the two ends of the current-to-voltage resistor (4) are connected to the analog input end of a programmable controller (5).