Three-phase current sensor for motor controller

Abstract

A three-phase current sensor for a motor controller comprises a shell and a circuit board, the shell is provided with three copper bar jacks, each copper bar jack is provided with a U-shaped block used for shielding external magnetic field interference, the lower portion of each U-shaped block is fixed in the shell, an opening of each U-shaped block is upward, two side arms of each U-shaped block extend out of the shell, and the upper end of each U-shaped block is fixed to the circuit board. The copper bar jack is located in an opening of the U-shaped block, the upper end of the copper bar jack is respectively provided with a plurality of welding pins, the welding pins extend upwards to be welded with a circuit of the circuit board, the lower end of the circuit board is welded and fixed with three TMR chips, each TMR chip is located in the opening of the U-shaped block, the lower end of the circuit board is welded and fixed with three wire holders used for grounding, and the wire holders are connected with the circuit board. Each wire holder is in contact with the corresponding U-shaped block, the lower part of the shell is provided with three copper bar fixing arms, the three copper bar fixing arms are respectively located below the three copper bar jacks, and each copper bar fixing arm is provided with a fixing nut.

Description

Technical Field

[0001] The utility model relates to the field of current sensors, in particular to a three-phase current sensor for a motor controller. Background Art

[0002] The voltage platform of the motor controller for new energy vehicles tends to be high voltage, and the three-phase current of the motor also increases accordingly. The accuracy of the detection of the three-phase copper busbar current of the motor determines the stability and safety of driving. At present, the mainstream method for detecting the three-phase copper busbar current is the Hall solution, which has the characteristics of low loss, self-isolation, and low cost. It mainly improves the accuracy of detection by magnetic core magnetic concentration. However, the Hall chip is highly sensitive to temperature, so the numerical difference of the same current detected by the Hall chip under high and low temperature conditions is large. At the same time, the accuracy of the Hall chip for large current detection is relatively low, which is less and less suitable for the motor controller of new energy vehicles with increasing three-phase current. Summary of the invention

[0003] The purpose of the utility model is to provide a three-phase current sensor for a motor controller to address the corresponding deficiencies of the prior art. The three-phase current sensor for a motor controller can improve the accuracy of the motor controller in detecting large currents, the consistency of measurement under high and low temperature conditions, and has good anti-interference ability and superior performance.

[0004] The purpose of the utility model is achieved by adopting the following scheme: a three-phase current sensor for a motor controller, comprising a shell and a circuit board, wherein the shell is provided with three copper bar jacks, and each copper bar jack is respectively provided with a U-shaped block for shielding external magnetic field interference, the lower part of the U-shaped block is fixed in the shell, the U-shaped block opens upward, and two side arms extend out of the shell, and the upper end is fixed to the circuit board, the copper bar jack is located in the opening of the U-shaped block, and a plurality of welding pins are respectively provided at the upper end of the copper bar jack, and the welding pins extend upward and are welded with the circuit of the circuit board, and three TMR chips are welded and fixed at the lower end of the circuit board, and each TMR chip is located in the opening of the U-shaped block, and three wiring seats for grounding are welded and fixed at the lower end of the circuit board, and each wiring seat contacts the corresponding U-shaped block, and three copper bar fixing arms are arranged at the lower part of the shell, and the three copper bar fixing arms are respectively located below the three copper bar jacks, and each copper bar fixing arm is provided with a fixing nut.

[0005] The circuit board is provided with four mounting holes for mounting U-shaped blocks and via holes for soldering pins to pass through.

[0006] The U-shaped block is made by stacking a plurality of Permalloy pieces.

[0007] The U-shaped block and the shell are integrally injection molded.

[0008] The wiring seat is a copper wiring seat, and the wiring seat is contacted and connected with the U-shaped block through a spring sheet.

[0009] The welding pin is a copper welding pin, which is arranged on a welding pin column on the shell, and four welding pins are symmetrically arranged on the shell.

[0010] A positioning column is arranged on the shell in the middle of the welding pin.

[0011] The fixing nut is a copper nut, and the fixing nut and the housing are integrally injection molded.

[0012] The advantages of the utility model are: 1. The three-phase current sensor for the motor controller adopts TMR chip instead of Hall chip as the sensing unit. Due to the high sensitivity and good temperature stability of the TMR chip, the sensor can detect the large current of the motor controller and avoid the problem of low testing accuracy of the Hall current sensor under high temperature conditions.

[0013] 2. The U-shaped block made of Permalloy not only shields the interference of the external magnetic field on the chip, but also gathers the magnetic field generated by large current. The copper terminal block grounds the U-shaped block, which can reduce the eddy current generated by alternating current and improve measurement accuracy.

[0014] 3. The fixing nut, welding pin and terminal block are all made of copper to reduce electromagnetic interference and improve the accuracy of detection.

[0015] The utility model can improve the accuracy of large current detection of the motor controller and the consistency of measurement under high and low temperature conditions, has good anti-interference ability and superior performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the structure of the utility model;

[0017] Figure 2 It is a top view of the utility model;

[0018] Figure 3 This is the front view of the utility model;

[0019] Figure 4 This is a cross-sectional view of the utility model;

[0020] Figure 5 This is a schematic diagram of the wiring socket structure in the utility model. DETAILED DESCRIPTION

[0021] like Figures 1 to 5As shown, a three-phase current sensor for a motor controller includes a housing 3 and a circuit board 2. The housing 3 is provided with three copper bar sockets 8. Each copper bar socket 8 is respectively provided with a U-shaped block 1 for shielding external magnetic field interference. The U-shaped block 1 is made of multiple Permalloy blocks stacked. Multiple Permalloy blocks stacked can reduce the eddy current generated by alternating current. The lower part of the U-shaped block 1 is fixed in the housing 3, and the U-shaped block 1 and the housing 3 are integrally injection molded. The U-shaped block 1 opens upward, and the two side arms extend out of the housing 3, and the upper end is fixed to the circuit board 2. The copper bar socket 8 is located in the opening of the U-shaped block 1. A plurality of welding pins 6 are respectively provided at the upper end of the copper bar socket 8. The welding pins 6 extend upward to be welded with the circuit of the circuit board 2. The circuit board 2 is provided with 4 mounting holes 10 for mounting the U-shaped block 1 and a through hole 11 for the welding pin 6 to pass through. The welding pin 6 is a copper welding pin, and the welding pin 6 is arranged on the welding pin column 3-2 on the housing 3, and 4 welding pins are symmetrically arranged on the housing 3. A positioning column 7 is arranged on the shell 3 in the middle of the welding pin 6. The positioning column 7 positions the circuit board 2. Three TMR chips 9 are welded and fixed at the lower end of the circuit board 2, and each TMR chip 9 is located in the opening of the U-shaped block 1. Three terminal blocks 5 for grounding are welded and fixed at the lower end of the circuit board 2. Each terminal block 5 is in contact with the corresponding U-shaped block 1. The terminal block 5 is a copper terminal block, and the terminal block 5 is closely connected with the U-shaped block 1 through a spring piece 5a. The terminal block 5 can reduce the influence of the eddy current generated by the alternating current on the sensor. Three copper bar fixing arms 3-1 are arranged at the lower part of the shell 3, and the three copper bar fixing arms 3-1 are respectively located below the three copper bar jacks 8, and each copper bar fixing arm 3-1 is provided with a fixing nut 4. The fixing nut 4 is a copper nut, and the fixing nut 4 is integrally injection molded with the shell 3.

[0022] The U-shaped block 1 in the three-phase current sensor for the motor controller can also be replaced with a U-shaped block 1 made of silicon steel sheet or ferrite according to usage, and the TMR chip can be replaced with other chips.

[0023] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modification made to the present invention by those skilled in the art without departing from the spirit of the present invention shall fall within the protection scope of the present invention.

Claims

1. A three-phase current sensor for a motor controller, comprising a housing (3) and a circuit board (2), wherein the housing (3) is provided with three copper busbar jacks (8), characterized in that: A U-shaped block (1) for shielding external magnetic field interference is respectively arranged at each copper busbar socket (8); the lower part of the U-shaped block (1) is fixed in the housing (3); the U-shaped block (1) opens upward; two side arms extend out of the housing (3); the upper end is fixed to the circuit board (2); the copper busbar socket (8) is located in the opening of the U-shaped block (1); a plurality of soldering pins (6) are respectively arranged at the upper end of the copper busbar socket (8); the soldering pins (6) extend upward to be soldered to the circuit of the circuit board (2); the circuit board (2) Three TMR chips (9) are welded and fixed at the lower end, and each TMR chip (9) is located in an opening of the U-shaped block (1). Three wiring sockets (5) for grounding are welded and fixed at the lower end of the circuit board (2), and each wiring socket (5) is in contact with the corresponding U-shaped block (1). Three copper bar fixing arms (3-1) are arranged at the lower part of the shell (3), and the three copper bar fixing arms (3-1) are respectively located below the three copper bar jacks (8), and each copper bar fixing arm (3-1) is provided with a fixing nut (4).

2. The three-phase current sensor for a motor controller according to claim 1, characterized in that: The circuit board (2) is provided with four mounting holes (10) for mounting the U-shaped blocks (1) and through holes (11) for the soldering pins (6) to pass through.

3. The three-phase current sensor for a motor controller according to claim 1 or 2, characterized in that: The U-shaped block (1) is made by stacking a plurality of Permalloy pieces.

4. The three-phase current sensor for a motor controller according to claim 1 or 2, characterized in that: The U-shaped block (1) and the shell (3) are integrally injection molded.

5. The three-phase current sensor for a motor controller according to claim 1, characterized in that: The wiring seat (5) is a copper wiring seat, and the wiring seat (5) is contact-connected with the U-shaped block (1) via a spring sheet (5a).

6. The three-phase current sensor for a motor controller according to claim 1, characterized in that: The welding needle (6) is a copper welding needle, and the welding needle (6) is arranged on a welding needle column (3-2) on the shell (3). Four welding needles are symmetrically arranged on the shell (3).

7. The three-phase current sensor for a motor controller according to claim 1, characterized in that: A positioning column (7) is provided on the housing (3) in the middle of the welding needle (6).

8. The three-phase current sensor for a motor controller according to claim 1, characterized in that: The fixing nut (4) is a copper nut, and the fixing nut (4) and the housing (3) are integrally injection molded.

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