Permanent magnet driving current-limiting protection circuit based on single Hall current sampling

Abstract

The utility model relates to a permanent magnet driving current-limiting protection circuit based on single Hall current sampling, which comprises a permanent magnet driving module connected with a Hall current output circuit through a bus loop, the Hall current output circuit connected with an overcurrent comparison circuit, and the overcurrent comparison circuit connected with the permanent magnet driving module through an input / output interface. And the over-current threshold reference circuit is connected with the over-current comparison circuit. According to the permanent magnet driving current-limiting protection circuit based on single Hall current sampling, the permanent magnet driving module, the Hall current output circuit, the over-current comparison circuit, the over-current threshold reference circuit and the like are matched; the design is simple and easy to realize, the cost is low, the system stability is high, a complex power supply system is not needed, and the bus loop is not cut off to ensure the stress of the permanent magnet driving module.

Description

Technical Field

[0001] The utility model relates to the technical field of permanent magnet drive, in particular to a permanent magnet drive current limiting protection circuit based on single Hall current sampling. Background Art

[0002] Traditional overcurrent protection requires the combination of Hall current sensors and IGBTs to achieve overcurrent hard shutdown. This combination scheme has complex circuit design and numerous power supply systems. The hard shutdown cuts off the bus loop of the drive circuit, and the increased IGBT stress can easily lead to system instability and IGBT explosion. Utility Model Content

[0003] In view of the deficiencies in the prior art, the utility model provides a permanent magnet drive current limiting protection circuit based on single Hall current sampling, which has a simple design, is easy to implement, has low cost and high system stability.

[0004] The utility model is realized through the following technical solutions:

[0005] A permanent magnet drive current limiting protection circuit based on single Hall current sampling, comprising:

[0006] The permanent magnet drive module is connected to the Hall current output circuit through the bus circuit, and is used to provide a drive circuit for the Hall current output circuit to realize the opening and closing operation;

[0007] The Hall current output circuit is connected to the overcurrent comparison circuit and is used to receive the current signal sent by the permanent magnet drive module and send it to the overcurrent comparison circuit;

[0008] The overcurrent comparison circuit is connected to the permanent magnet drive module through the input and output interface, and transmits the high voltage signal or the low voltage signal to the permanent magnet drive module through the overcurrent comparison;

[0009] The overcurrent threshold reference circuit is connected to the overcurrent comparison circuit and is connected to the permanent magnet drive module through an input and output interface, and is used to output a reference voltage to the overcurrent comparison circuit.

[0010] In a preferred embodiment of the present invention, the permanent magnet drive module adopts a body-type permanent magnet drive device.

[0011] Specifically, the Hall current output circuit includes a Hall current sensor U2 and a capacitor C2, and the Hall current sensor U2 is connected to the capacitor C2.

[0012] Specifically, the overcurrent comparison circuit includes an operational amplifier U1, an input resistor R5, a filter resistor R6, a filter capacitor C4 and a pull-up resistor R4. The filter resistor R6 and the filter capacitor C4 constitute a filter circuit, which is connected to the Hall current sensor U2 and the operational amplifier U1. The operational amplifier U1 is connected to the input and output interface through the pull-up resistor R4, and the operational amplifier U1 is connected to the overcurrent threshold reference circuit through the input resistor R5.

[0013] Specifically, the overcurrent threshold reference circuit includes a reference voltage chip T1, a current limiting resistor R1, a voltage dividing resistor R2, and a voltage dividing resistor R3. The reference voltage chip T1 is connected to the current limiting resistor R1, the voltage dividing resistor R2, the voltage dividing resistor R3, and the input resistor R5 respectively.

[0014] The beneficial effects of the utility model are as follows: the permanent magnet drive current limiting protection circuit based on single Hall current sampling is coordinated through a permanent magnet drive module, a Hall current output circuit, an overcurrent comparison circuit, an overcurrent threshold reference circuit, etc., and has a simple design, is easy to implement, has low cost, high system stability, does not require a complex power supply system, and the bus circuit will not be cut off, thereby ensuring the stress of the permanent magnet drive module. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a structural block diagram of the permanent magnet drive current limiting protection circuit based on single Hall current sampling of the utility model;

[0016] Figure 2 The utility model is a circuit schematic diagram of a permanent magnet drive current limiting protection circuit based on single Hall current sampling. DETAILED DESCRIPTION

[0017] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the protection scope of the present invention.

[0018] like Figure 1 A permanent magnet drive current limiting protection circuit based on single Hall current sampling is shown, comprising a permanent magnet drive module 1, a Hall current output circuit 3, an overcurrent comparison circuit 4 and an overcurrent threshold reference circuit 5, wherein the permanent magnet drive module 1 is connected to the Hall current output circuit 3 through a bus loop 2, the Hall current output circuit 3 is connected to the overcurrent comparison circuit 4, the overcurrent comparison circuit 4 is connected to the permanent magnet drive module 1 through an input-output interface 6, the overcurrent threshold reference circuit 5 is connected to the overcurrent comparison circuit 4, and is connected to the permanent magnet drive module 1 through the input-output interface 6.

[0019] Specifically, combined Figure 2As shown, the bus loop interface J2 of the permanent magnet drive module is connected in series with the Hall current output circuit. The permanent magnet drive module supplies power to the current limiting protection circuit through the bus loop interface J2. The bus loop interface J2 also outputs an overcurrent signal to the permanent magnet drive module. The Hall current sensor U2 and capacitor C2 form a Hall current output circuit. The Hall current sensor U2 statically outputs 2.5V. When the current flowing through the Hall current sensor U2 increases by 1A, the voltage increases by 0.04V. The precision voltage chip T1, current limiting resistor R1, voltage dividing resistor R2, and voltage dividing resistor R3 form an overcurrent threshold reference circuit. The precision voltage chip T1 is a TL431 precision voltage chip, the current limiting resistor R1 is 470Ω, the voltage dividing resistor R2 is 4.7KΩ, and the voltage dividing resistor R3 is 12.4KΩ. The permanent magnet drive module provides a 5V power supply through the bus loop interface J2. The overcurrent threshold reference circuit outputs a VREF (reference) voltage of 3.45V. Every 0.04V is 1A current, and the overcurrent threshold is converted to 24A; the operational amplifier U1, the input resistor R5, and the filter Resistor R6, pull-up resistor R4, and filter capacitor C4 form an overcurrent comparison circuit. Operational amplifier U1 is an LM358 operational amplifier. Input resistor R5 is 1KΩ, filter resistor R6 is 1KΩ, filter capacitor C4 is 100nF, forming a filter circuit. Pull-up resistor R4 is 2KΩ. The negative phase terminal of pin 4 of operational amplifier U1 receives the overcurrent threshold reference voltage, and the positive phase terminal of pin 3 receives the Hall current output voltage. When the voltage of pin 4 is greater than the voltage of pin 3, operational amplifier pin 1 outputs a low voltage. When the voltage of pin 3 is greater than the voltage of pin 4, operational amplifier pin 1 outputs a high voltage through pull-up resistor R4.

[0020] The working principle of the utility model is as follows:

[0021] When the permanent magnet drive module performs opening and closing operations, current flows through the bus circuit interface J2. When the current circuit current is less than 24A, the output voltage of the Hall current sensor U2 is less than 3.45V, and a low voltage is output through overcurrent comparison. The input and output interface J1 transmits the low voltage signal to the permanent magnet drive module, and the permanent magnet drive module performs normal opening and closing operations. When the bus circuit current is greater than 24A, the output voltage of the Hall current sensor U2 is greater than 3.45V, and a high voltage is output through the overcurrent comparison output high-resistance pull-up resistor R4. The input and output interface J1 transmits the high voltage signal to the permanent magnet drive module, and the permanent magnet drive module instantly cuts off the opening and closing operations. When the bus circuit current drops below 24A, the output voltage of the Hall current sensor U2 is less than 3.45V again, and a low voltage signal is output through overcurrent comparison. The bus circuit interface J2 outputs a low voltage signal to the permanent magnet drive module, and the permanent magnet drive module instantly resumes operation and performs dynamic operation until the opening and closing operations are completed, limiting the current to 24A.

[0022] The above-mentioned embodiments only express several implementation methods of the utility model, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the utility model patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the utility model, which all belong to the protection scope of the utility model.

Claims

1. A permanent magnet drive current limiting protection circuit based on single Hall current sampling, characterized in that: It includes a permanent magnet drive module, which is connected to the Hall current output circuit through a bus circuit and is used to provide a drive circuit for the Hall current output circuit to realize opening and closing operations; The Hall current output circuit is connected to the overcurrent comparison circuit and is used to receive the current signal sent by the permanent magnet drive module and send it to the overcurrent comparison circuit; The overcurrent comparison circuit is connected to the permanent magnet drive module through the input and output interface, and transmits the high voltage signal or the low voltage signal to the permanent magnet drive module through the overcurrent comparison; The overcurrent threshold reference circuit is connected to the overcurrent comparison circuit and is connected to the permanent magnet drive module through an input and output interface, and is used to output a reference voltage to the overcurrent comparison circuit.

2. The permanent magnet drive current limiting protection circuit based on single Hall current sampling according to claim 1 is characterized in that: The permanent magnet drive module adopts a body type permanent magnet drive device.

3. The permanent magnet drive current limiting protection circuit based on single Hall current sampling according to claim 2 is characterized in that: The Hall current output circuit includes a Hall current sensor U2 and a capacitor C2, and the Hall current sensor U2 is connected to the capacitor C2.

4. The permanent magnet drive current limiting protection circuit based on single Hall current sampling according to claim 3 is characterized in that: The overcurrent comparison circuit includes an operational amplifier U1, an input resistor R5, a filter resistor R6, a filter capacitor C4 and a pull-up resistor R4. The filter resistor R6 and the filter capacitor C4 constitute a filter circuit, which is connected to the Hall current sensor U2 and the operational amplifier U1. The operational amplifier U1 is connected to the input and output interface through the pull-up resistor R4, and the operational amplifier U1 is connected to the overcurrent threshold reference circuit through the input resistor R5.

5. The permanent magnet drive current limiting protection circuit based on single Hall current sampling according to claim 4 is characterized in that: The overcurrent threshold reference circuit includes a reference voltage chip T1, a current limiting resistor R1, a voltage dividing resistor R2, and a voltage dividing resistor R3. The reference voltage chip T1 is connected to the current limiting resistor R1, the voltage dividing resistor R2, the voltage dividing resistor R3, and the input resistor R5 respectively.

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