Three-phase power supply open-phase detection circuit
By using a circuit design with bidirectional optocouplers and a DC power supply, the phase loss detection of three-phase power supply is simplified, solving the problems of circuit complexity and misjudgment in the existing technology, and realizing high reliability and high accuracy phase loss detection.
Patent Information
- Application Number
- CN202423062216.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-12
- Publication Date
- 2026-02-10
- Estimated Expiration
- 2034-12-12
AI Technical Summary
Existing three-phase power supply detection circuits are complex, have many components, and low reliability. They are also prone to misjudgment at low voltages and cannot effectively detect phase loss problems.
The circuit design employs three bidirectional optocouplers and a DC power supply. By connecting the corresponding phase lines of the three-phase power supply, the external three-phase rectifier diodes are eliminated, and the three-phase power supply phase loss detection is achieved using bidirectional optocouplers.
The circuit structure was simplified, the number of components was reduced, the reliability and accuracy of detection were improved, and false judgments at low voltage were avoided.
Smart Images
Figure CN223897549U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of power supply technology, specifically relating to a three-phase power supply phase loss detection circuit. Background Technology
[0002] In equipment or appliances such as power meters, automatic control systems, and household appliances, it is often necessary to detect the problem of phase loss in three-phase power supply. This is because many loads are powered by three-phase power. If a phase is lost, the equipment or appliance will not be able to work properly, and may even be damaged after prolonged operation.
[0003] See Figure 1 Currently, the three-phase power supply detection circuits used in the market are quite complex. Most of them use the method of resistor voltage division and then rectification for detection, which has the disadvantages of many components, low reliability, and complex detection circuits. Moreover, the circuit components are easy to damage, and the detection accuracy is not high, especially at low voltage, where false judgments are prone to occur. Utility Model Content
[0004] The purpose of this invention is to provide a three-phase power supply phase loss detection circuit to solve the above-mentioned technical problems.
[0005] This application provides a three-phase power supply phase loss detection circuit for connecting a three-phase power supply and a processing module. The three-phase power supply phase loss detection circuit includes: three bidirectional optocouplers and a DC power supply; wherein...
[0006] The anode of each bidirectional optocoupler is connected to the corresponding phase line of the three-phase power supply through a corresponding first resistor;
[0007] The negative terminals of each bidirectional optocoupler are all connected;
[0008] The collector of each bidirectional optocoupler is connected to the phase signal output terminal and is connected to the positive terminal of the DC power supply through a second resistor;
[0009] The emitter of each bidirectional optocoupler is connected to the negative terminal of a DC power supply.
[0010] In one embodiment of this application, the bidirectional optocoupler is model LTV-354T.
[0011] In one embodiment of this application, the first resistor is of type 75K / 1% / 1206.
[0012] In one embodiment of this application, the second resistor is of type 1K / 1% / 0603.
[0013] In one embodiment of this application, the voltage of the DC power supply is 3.3V.
[0014] The advantages of this invention are: fewer components, easier wiring, and higher testing reliability.
[0015] Unlike existing technologies, this application provides a three-phase power supply phase loss detection circuit for connecting a three-phase power supply and a processing module. The circuit includes: three bidirectional optocouplers and a DC power supply; the anodes of each bidirectional optocoupler are connected to the corresponding phase lines of the three-phase power supply via corresponding first resistors; the cathodes of each bidirectional optocoupler are interconnected; the collectors of each bidirectional optocoupler are connected to the phase signal output terminal and connected to the positive terminal of the DC power supply via second resistors; and the emitters of each bidirectional optocoupler are connected to the negative terminal of the DC power supply. This three-phase power supply phase loss detection circuit eliminates the need for external three-phase rectifier diodes, achieving the same effect using only bidirectional optocouplers. It requires very few components to detect three-phase power supply phase loss; and only one phase signal output terminal needs to be connected to the processing module to detect the phase loss.
[0016] Other features and advantages of this invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objectives and other advantages of this invention are realized and obtained through the structures particularly pointed out in the description and the accompanying drawings.
[0017] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description
[0018] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.
[0019] Figure 1 It is a detection circuit based on existing technology;
[0020] Figure 2 This is a schematic diagram of a preferred embodiment of the three-phase power supply phase loss detection circuit of this utility model;
[0021] Figure 3 This is a schematic diagram of the waveform and phase signal output when a three-phase power supply is operating normally;
[0022] Figure 4 This is a schematic diagram of the waveform and phase signal output when a phase of a three-phase power supply is missing. Detailed Implementation
[0023] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.
[0024] This application provides a three-phase power supply phase loss detection circuit, which will be described in detail below. It should be noted that the order of description of the following embodiments is not intended to limit the preferred order of the embodiments of this application. Furthermore, the descriptions of each embodiment have their own emphasis; parts not described in detail in a certain embodiment can be referred to in the relevant descriptions of other embodiments.
[0025] To address the existing technical problems, one embodiment of this application provides a three-phase power supply phase loss detection circuit for connecting a three-phase power supply and a processing module. The circuit is characterized by comprising: three bidirectional optocouplers and a DC power supply; wherein the anode of each bidirectional optocoupler is connected to the corresponding phase line of the three-phase power supply via a corresponding first resistor; the cathodes of each bidirectional optocoupler are all connected to each other; the collector of each bidirectional optocoupler is connected to the phase signal output terminal and is connected to the positive terminal of the DC power supply via a second resistor; and the emitter of each bidirectional optocoupler is connected to the negative terminal of the DC power supply.
[0026] For details, see Figure 2 The three phase lines of the three-phase power supply are L1, L2, and L3; the three bidirectional optocouplers are U1, U2, and U3, with terminals 1 to 4 being the anode, cathode, emitter, and collector, respectively; the three first resistors are R2, R3, and R4; and the second resistor is R1. When the three-phase voltage is operating normally, the AC_phase signal is pulled low. When any phase of the three-phase voltage (L1, L2, or L3) is missing, the corresponding optocoupler will not conduct, and the AC_phase signal will be pulled high.
[0027] Optionally, the bidirectional optocoupler can be of the model LTV-354T.
[0028] Optionally, the first resistor can be of the following type: 75K / 1% / 1206.
[0029] Optionally, the second resistor can be of the following type: 1K / 1% / 0603.
[0030] Optionally, the processing module can be model number MM32SPIN06.
[0031] Optionally, the voltage of the DC power supply is 3.3V.
[0032] In one application scenario, see Figure 3 When the three-phase power supply is normal, the AC_phase signal output is low, and the low level is lower than 0.1 times the VCC voltage; see [link / reference]. Figure 4 When any one phase of a three-phase power supply is missing, the optocoupler of the corresponding phase will not conduct, causing the AC_ phase signal to be periodically pulled high. At this time, it can be determined that a phase is missing.
[0033] In summary, the three-phase power supply phase loss detection circuit of this application eliminates the need for external three-phase rectifier diodes. It can achieve the same effect as external three-phase rectifier diodes using only bidirectional optocouplers, requiring only a few components to realize three-phase power supply phase loss detection. Only one phase signal output terminal needs to be connected to the processing module to detect the phase loss.
[0034] It should be noted that all the devices (parts whose specific structures are not specified) selected in this application are general standard parts or parts known to those skilled in the art, and their structures and principles can be known to those skilled in the art through technical manuals or conventional experimental methods.
[0035] In the description of the embodiments of this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.
[0036] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.
[0037] Based on the above-described preferred embodiments of this utility model, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the technical concept of this utility model. The technical scope of this utility model is not limited to the contents of the specification, but must be determined according to the scope of the claims.
Claims
1. A three-phase power supply phase loss detection circuit, used to connect a three-phase power supply and a processing module, characterized in that, include: Three bidirectional optocouplers and a DC power supply; in The anode of each bidirectional optocoupler is connected to the corresponding phase line of the three-phase power supply through a corresponding first resistor; The negative terminals of each bidirectional optocoupler are all connected; The collector of each bidirectional optocoupler is connected to the phase signal output terminal and is connected to the positive terminal of the DC power supply through a second resistor; The emitter of each bidirectional optocoupler is connected to the negative terminal of a DC power supply.
2. The three-phase power supply phase loss detection circuit according to claim 1, characterized in that, The model of the bidirectional optocoupler is LTV-354T.
3. The three-phase power supply phase loss detection circuit according to claim 1, characterized in that, The first resistor is of type 75K / 1% / 1206.
4. The three-phase power supply phase loss detection circuit according to claim 1, characterized in that, The second resistor is of model number 1K / 1% / 0603.
5. The three-phase power supply phase loss detection circuit according to claim 1, characterized in that, The voltage of the DC power supply is 3.3V.