PDU three-phase imbalance detection circuit

Abstract

The utility model discloses a PDU three-phase imbalance detection circuit comprising a current transformer P1, a first electrolytic capacitor CE1, a second electrolytic capacitor CE2, a bridge rectifier DB1, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a voltage stabilizing diode Z1, a first capacitor C1, a second capacitor C2, a third capacitor C3, a micro-control unit U1 and a first light indication unit. The current transformer P1 is connected with the alternating current input end of the bridge rectifier DB1, the second electrolytic capacitor CE2 is connected to the direct current output end of the bridge rectifier DB1, the third resistor R3 and the fourth resistor R4 are connected in series between the positive electrode of the second electrolytic capacitor CE2 and the VSS end of the micro-control unit U1, the first light indication unit comprises a first indicator light LED1 and a fifth resistor R5, and the fifth resistor R5 is connected with the second indicator light LED1. An external power supply is not needed, the cost is low, the corresponding indicator lamp is driven according to the level of the unbalanced current, and a user can conveniently identify the unbalanced level according to the indicator lamp and adjust load access.

Description

Technical Field

[0001] This utility model relates to the field of PDUs, and in particular to a three-phase imbalance detection circuit for PDUs. Background Technology

[0002] In the actual use of three-phase PDUs, multiple loads need to be connected. Due to the imbalance of load connection, it is easy to cause problems such as increased power loss of the line, increased power loss of the distribution transformer, reduced output of the distribution transformer, and zero-sequence current generated by the distribution transformer, which affect the safe operation of electrical equipment.

[0003] To address the load imbalance issue in three-phase PDUs, the three-phase operating current of the PDU can be detected and compared. Based on predetermined imbalance indicators, a judgment can be made, prompting the user to adjust the load connection, thereby achieving balanced three-phase power consumption. However, this requires an external power supply, and how to prompt the user to adjust the load connection is also a challenge that needs improvement. Utility Model Content

[0004] The main technical problem solved by this utility model is to provide a PDU three-phase imbalance detection circuit to realize the detection of PDU three-phase imbalance and indicate the imbalance status.

[0005] To solve the above-mentioned technical problems, the present invention provides a three-phase unbalance detection circuit for a PDU, comprising: a current transformer P1, a first electrolytic capacitor CE1, a second electrolytic capacitor CE2, a bridge rectifier DB1, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a Zener diode Z1, a first capacitor C1, a second capacitor C2, a third capacitor C3, a microcontroller unit U1, and a first indicator light unit. The current transformer P1 is connected to the AC input terminal of the bridge rectifier DB1, the second electrolytic capacitor CE2 is connected to the DC output terminal of the bridge rectifier DB1, the first resistor R1 and the Zener diode Z1 are connected in series across the second electrolytic capacitor CE2, and the second resistor R2 and the first resistor R1 are connected in series across the first resistor R2. Resistor R1 is connected in parallel. The first capacitor C1, the second capacitor C2, and the first electrolytic capacitor CE1 are connected in parallel across the Zener diode Z1. One end of the first electrolytic capacitor CE1 is connected to the VDD terminal of the microcontroller unit U1 for power supply. The third resistor R3 and the fourth resistor R4 are connected in series between the positive terminal of the second electrolytic capacitor CE2 and the VSS terminal of the microcontroller unit U1 to form a voltage divider circuit. The third capacitor C3 and the fourth resistor R4 are connected in parallel. An OVP overvoltage protection circuit is provided between the input terminal of the fourth resistor R4 and the P00 terminal of the microcontroller unit U1. The first light indicator unit includes a first indicator LED1 and a fifth resistor R5. The first indicator LED1 is connected in series between the P04 terminal of the microcontroller unit U1 and one end of the fifth resistor R5.

[0006] In a preferred embodiment of this utility model, the other end of the fifth resistor R5 is grounded.

[0007] In a preferred embodiment of the present invention, a second light indicator unit is further included. The second light indicator unit includes a second indicator LED2 and a sixth resistor R6. The second indicator LED2 is connected in series between the P17 terminal of the microcontroller U1 and one end of the sixth resistor R6.

[0008] In a preferred embodiment of this invention, the other end of the sixth resistor R6 is grounded.

[0009] In a preferred embodiment of the present invention, a third light indicator unit is further included. The third light indicator unit includes a third indicator LED3 and a seventh resistor R7. The third indicator LED3 is connected in series between the P15 terminal of the microcontroller U1 and one end of the seventh resistor R7, and the other end of the seventh resistor R7 is grounded.

[0010] In a preferred embodiment of the present invention, a fourth light indicator unit is further included. The fourth light indicator unit includes a fourth indicator LED4 and an eighth resistor R8. The eighth resistor R8 and the fourth indicator LED4 are connected in series between the VDD terminal and the P16 terminal of the microcontroller U1.

[0011] In a preferred embodiment of this utility model, the Zener diode Z1 regulates the DC voltage signal to 3.3V, providing the operating voltage for the microcontroller unit U1.

[0012] The beneficial effects of this utility model are as follows: The three-phase unbalance detection circuit for PDU disclosed in this utility model uses a current transformer P1 fitted onto the three-phase circuit of the PDU to detect unbalanced current. It does not require an external power supply, has low cost, and uses a bridge rectifier DB1 to rectify the unbalanced current into a DC voltage signal. The microcontroller U1 determines the overcurrent level by detecting the voltage value of the OVP overvoltage protection circuit and drives the corresponding indicator light according to the level of unbalanced current. This allows users to easily identify the unbalance level by the indicator light and adjust the load connection, making it simple and clear. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort, wherein:

[0014] Figure 1This is a schematic diagram of a preferred embodiment of a PDU three-phase unbalance detection circuit according to the present invention. Detailed Implementation

[0015] The technical solutions in the embodiments of this utility model will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. 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.

[0016] Please see Figure 1 The embodiments of this utility model include:

[0017] like Figure 1 The PDU three-phase unbalance detection circuit shown includes: a current transformer P1, a first electrolytic capacitor CE1, a second electrolytic capacitor CE2, a bridge rectifier DB1, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a Zener diode Z1, a first capacitor C1, a second capacitor C2, a third capacitor C3, a microcontroller unit U1, a first light indicator unit, a second light indicator unit, a third light indicator unit, and a fourth light indicator unit. In this embodiment, the current transformer P1 is used to detect the unbalanced current in the three-phase circuit of the PDU, eliminating the need for an external power supply and reducing detection costs.

[0018] Connect the current transformer P1 to the AC input terminal of the bridge rectifier DB1. The unbalanced current is rectified into a DC voltage signal by the bridge rectifier DB1. Connect the second electrolytic capacitor CE2 to the DC output terminal of the bridge rectifier DB1. The DC fluctuating voltage is filtered by the second electrolytic capacitor CE2 and converted into a stable DC voltage signal.

[0019] The first resistor R1 and the Zener diode Z1 are connected in series across the second electrolytic capacitor CE2, and the second resistor R2 is connected in parallel with the first resistor R1. In this embodiment, the DC voltage signal is regulated to 3.3V by the Zener diode Z1, which facilitates the provision of operating voltage for the microcontroller U1.

[0020] like Figure 1 As shown, the first capacitor C1, the second capacitor C2, and the first electrolytic capacitor CE1 are connected in parallel across the Zener diode Z1. One end of the first electrolytic capacitor CE1 is connected to the VDD terminal of the microcontroller U1 for power supply. The 3.3V voltage is filtered through the first electrolytic capacitor CE1 to provide a stable and clean voltage for the microcontroller U1.

[0021] The third resistor R3 and the fourth resistor R4 are connected in series between the positive terminal of the second electrolytic capacitor CE2 and the VSS terminal of the microcontroller unit U1 to form a voltage divider circuit. The third capacitor C3 and the fourth resistor R4 are connected in parallel. The voltage divided by the voltage divider circuit divides the voltage sensed by the current transformer P1 to a voltage that the microcontroller unit U1 can detect, which is used to determine the level of unbalanced current in the system.

[0022] In this embodiment, an OVP overvoltage protection circuit is provided between the input terminal of the fourth resistor R4 and the P00 terminal of the microcontroller unit U1. The microcontroller unit U1 (MCU) determines the overcurrent level by detecting the voltage value of the OVP overvoltage protection circuit, and drives the corresponding light indicator unit according to different unbalanced current levels so that the user can quickly identify the unbalance level.

[0023] like Figure 1 As shown, four light indicator units are used, including:

[0024] The first light indicator unit includes a first indicator LED1 and a fifth resistor R5. The first indicator LED1 is connected in series between the P04 terminal of the microcontroller U1 and one end of the fifth resistor R5. In this embodiment, the other end of the fifth resistor R5 is grounded. When the unbalanced current is at the 10A level, the microcontroller U1 controls the lighting of the first indicator LED1.

[0025] The second light indicator unit includes a second indicator LED2 and a sixth resistor R6. The second indicator LED2 is connected in series between the P17 terminal of the microcontroller U1 and one end of the sixth resistor R6. The other end of the sixth resistor R6 is grounded. When the unbalanced current is at the 30A level, the microcontroller U1 controls the second indicator LED2 to be lit.

[0026] The third light indicator unit includes a third indicator LED3 and a seventh resistor R7. The third indicator LED3 is connected in series between the P15 terminal of the microcontroller U1 and one end of the seventh resistor R7. The other end of the seventh resistor R7 is grounded. When the unbalanced current is at the 55A level, the microcontroller U1 controls the lighting of the third indicator LED3.

[0027] The fourth light indicator unit includes a fourth indicator LED4 and an eighth resistor R8. The eighth resistor R8 and the fourth indicator LED4 are connected in series between the VDD terminal and the P16 terminal of the microcontroller U1. In this embodiment, when the unbalanced current is at the level of 80A, the microcontroller U1 controls the lighting of the fourth indicator LED4.

[0028] In summary, the PDU three-phase unbalance detection circuit disclosed in this utility model can detect the three-phase unbalanced current of the PDU and illuminate the corresponding indicator light according to the level of unbalanced current, so as to facilitate users to adjust the load connection in a timely manner.

[0029] The above are merely embodiments of this utility model and do not limit the patent scope of this utility model. Any equivalent structural or procedural transformations made based on the content of this utility model specification, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this utility model.

Claims

1. A three-phase imbalance detection circuit for a PDU, characterized in that, include: The system includes a current transformer P1, a first electrolytic capacitor CE1, a second electrolytic capacitor CE2, a bridge rectifier DB1, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a Zener diode Z1, a first capacitor C1, a second capacitor C2, a third capacitor C3, a microcontroller U1, and a first indicator light unit. The current transformer P1 is connected to the AC input terminal of the bridge rectifier DB1. The second electrolytic capacitor CE2 is connected to the DC output terminal of the bridge rectifier DB1. The first resistor R1 and the Zener diode Z1 are connected in series across the second electrolytic capacitor CE2. The second resistor R2 is connected in parallel with the first resistor R1. The first capacitor C1, the second capacitor C2, and the third capacitor Z1 are connected in series across the second electrolytic capacitor CE2. An electrolytic capacitor CE1 is connected in parallel across the Zener diode Z1. One end of the first electrolytic capacitor CE1 is connected to the VDD terminal of the microcontroller U1 for power supply. The third resistor R3 and the fourth resistor R4 are connected in series between the positive terminal of the second electrolytic capacitor CE2 and the VSS terminal of the microcontroller U1 to form a voltage divider circuit. The third capacitor C3 and the fourth resistor R4 are connected in parallel. An OVP overvoltage protection circuit is provided between the input terminal of the fourth resistor R4 and the P00 terminal of the microcontroller U1. The first light indicator unit includes a first indicator LED1 and a fifth resistor R5. The first indicator LED1 is connected in series between the P04 terminal of the microcontroller U1 and one end of the fifth resistor R5.

2. The PDU three-phase imbalance detection circuit according to claim 1, characterized in that, The other end of the fifth resistor R5 is grounded.

3. The PDU three-phase imbalance detection circuit according to claim 1, characterized in that, It also includes a second light indicator unit, which includes a second indicator LED2 and a sixth resistor R6. The second indicator LED2 is connected in series between the P17 terminal of the microcontroller U1 and one end of the sixth resistor R6.

4. The PDU three-phase imbalance detection circuit according to claim 3, characterized in that, The other end of the sixth resistor R6 is grounded.

5. The PDU three-phase imbalance detection circuit according to claim 1, characterized in that, It also includes a third light indicator unit, which includes a third indicator LED3 and a seventh resistor R7. The third indicator LED3 is connected in series between the P15 terminal of the microcontroller U1 and one end of the seventh resistor R7, and the other end of the seventh resistor R7 is grounded.

6. The PDU three-phase imbalance detection circuit according to claim 1, characterized in that, It also includes a fourth light indicator unit, which includes a fourth indicator LED4 and an eighth resistor R8. The eighth resistor R8 and the fourth indicator LED4 are connected in series between the VDD terminal and the P16 terminal of the microcontroller U1.

7. The PDU three-phase imbalance detection circuit according to claim 1, characterized in that, The Zener diode Z1 regulates the DC voltage signal to 3.3V, providing the operating voltage for the microcontroller unit U1.

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