Excitation driving protection circuit of rotary transformer

Abstract

The invention discloses an excitation driving protection circuit of a rotary transformer. According to the scheme, the excitation driving protection circuit comprises a first operational amplifier U1A, a second operational amplifier U1B, a filter, a first capacitor C1, a second capacitor C2, a third capacitor C3, a fourth capacitor C4 and a fifth capacitor C5. The circuit comprises a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9 and a tenth resistor R10. Wherein the first operational amplifier U1A and the second operational amplifier U1B are used for carrying out reverse-phase amplification on an input excitation signal, and when an excitation signal output end is short-circuited to the ground or short-circuited to a power supply, the second capacitor C2 and the fourth capacitor C4 can be used for isolating a direct-current component in a corresponding loop, so that the loop current is effectively reduced; and the current of the output end is controlled within a safe range, so that the port protection of the excitation output of the vehicle-mounted motor controller is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of motor controllers, and in particular to an excitation drive protection circuit of a rotary transformer. Background Art

[0002] In the process of controlling the motor by the on-board motor controller, the current position of the motor rotor needs to be precisely calculated. At present, the rotor position is mainly detected by a rotary transformer, and the feedback signal is sent to the chip for hardware decoding, so that the main control CPU chip can obtain the motor speed and electronic rotor position. The rotary transformer has a total of 6 signals, two groups of two, forming three groups of differential signals, two groups of output signals are fed back to the decoding chip, and one group is the input excitation signal. The output signal has the characteristics of small current and high impedance of the entire loop; the input signal is the rotary transformer excitation signal, which has the characteristics of large current (200MA) and small loop impedance.

[0003] The input excitation signal of the rotary transformer is provided by the on-board motor controller. Since the input excitation signal has the characteristic of small loop impedance, when the excitation signal port of the on-board controller is short-circuited to the ground or short-circuited to the power supply, the main control board of the controller will be at risk of large current burning the excitation circuit. In the related art, a Chinese patent with application number 202222711549.4 provides a rotary transformer excitation drive protection circuit. This scheme utilizes the conduction characteristics of the transistor to achieve short power supply and short ground protection of the excitation output port of the on-board controller. However, the protection circuit provided by this scheme uses a large number of electronic devices such as diodes or transistors, which is costly and the circuit connection relationship is also complex. In order to reduce the complexity of the protection circuit, it is necessary to study a new type of rotary transformer excitation drive protection circuit. Summary of the invention

[0004] The present invention provides an excitation drive protection circuit of a rotary transformer, which is used to overcome at least one technical problem existing in the prior art.

[0005] An embodiment of the present invention provides an excitation drive protection circuit for a rotary transformer, comprising:

[0006] A first operational amplifier U1A, a second operational amplifier U1B, a filter, a first capacitor C1, a second capacitor C2, a third capacitor C3, a fourth capacitor C4, and a fifth capacitor C5; a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, and a tenth resistor R10; wherein,

[0007] The non-inverting input terminal of the first operational amplifier U1A is connected to a reference voltage source of a first amplitude, the inverting input terminal of the first operational amplifier U1A is respectively connected to one end of the first resistor R1, one end of the second resistor R2 and one end of the third capacitor C3, the other end of the first resistor R1 is connected to an excitation signal input terminal of a second amplitude, the positive power supply terminal of the first operational amplifier U1A is connected to a voltage source of a third amplitude, the negative power supply terminal of the first operational amplifier U1A is grounded, the output terminal of the first operational amplifier U1A is respectively connected to one end of the third resistor R3 and one end of the fourth resistor R4; the other end of the fourth resistor R4 is respectively connected to the other end of the resistor R2 and the other end of the third capacitor C3;

[0008] One end of the first capacitor C1 is connected between the positive power supply terminal of the first operational amplifier U1A and the voltage source of the third amplitude, and the other end of the first capacitor C1 is grounded;

[0009] The non-inverting input terminal of the second operational amplifier U1B is connected to a reference voltage source of the first amplitude, and the inverting input terminal of the second operational amplifier U1B is respectively connected to one end of the fifth resistor R5, one end of the seventh resistor R7 and one end of the fifth capacitor C5; the output terminal of the second operational amplifier U1B is respectively connected to one end of the sixth resistor R6 and one end of the eighth resistor R8, and the other end of the sixth resistor R6 is respectively connected to the other end of the fifth resistor R5 and one end of the seventh resistor R7;

[0010] The positive power supply terminal of the second operational amplifier U1B is connected to a positive voltage source of a fourth amplitude, the negative power supply terminal of the second operational amplifier U1B is grounded, and the output terminal of the second operational amplifier U1B is connected to a negative voltage source of a fifth amplitude;

[0011] The other end of the third resistor R3 is connected to the first input port of the filter, the other end of the eighth resistor R8 is connected to the second input port of the filter, the first output port of the filter is connected to one end of the second capacitor C2, and the second output port of the filter is connected to one end of the fourth capacitor C4; the other end of the second capacitor C2 serves as a first excitation signal output end; the other end of the fourth capacitor C4 serves as a second excitation signal output end; the other end of the second capacitor C2 is connected to one end of the tenth resistor R10, the other end of the fourth capacitor C4 is connected to one end of the ninth resistor R9, and the other end of the ninth resistor R9 is connected to the other end of the tenth resistor R10 and then grounded.

[0012] Preferably, the third resistor R3 is a first equivalent resistor obtained by connecting the eleventh resistor R11 and the thirteenth resistor R13 in parallel, and a second equivalent resistor obtained by connecting the twelfth resistor R12 and the fourteenth resistor R14 in parallel in series.

[0013] Preferably, the eighth resistor R8 is a third equivalent resistor obtained by connecting a fifteenth resistor R15 and a seventeenth resistor R17 in parallel, and a fourth equivalent resistor obtained by connecting a sixteenth resistor R16 and an eighteenth resistor R18 in parallel in series.

[0014] Preferably, the other end of the second capacitor C2 is connected to one end of the first inductor L1 , and the other end of the first inductor L1 is used as the first excitation signal output end.

[0015] Preferably, the other end of the fourth capacitor C4 is connected to one end of the second inductor L2, and the other end of the second inductor L2 is used as the second excitation signal output end.

[0016] Preferably, the second amplitude is smaller than the first amplitude; and the first amplitude is smaller than the third amplitude.

[0017] The technical effects of the embodiments of the present invention may include: in the protection circuit provided by the present invention, after the excitation signal is amplified and transformed by the operational amplifier circuit, a sine wave with a phase difference of 180 degrees from the original excitation signal is obtained, which serves as the input excitation signal of the resolver transformer. When EXC+ or EXC- is short-circuited to the ground, due to the characteristics of the capacitor that blocks direct current and passes alternating current, the DC component of the loop is isolated by the corresponding capacitor, thereby reducing the loop current, thereby achieving the protective effect of limiting the current size when the port is short-circuited to the ground. Similarly, when EXC+ or EXC- is short-circuited to the power supply, the DC component of the corresponding loop current is isolated by the corresponding capacitor, which also achieves the protective effect of limiting the current size when the port is short-circuited. The technical solution of the present invention makes full use of the conduction characteristics of the capacitor that blocks direct current and passes alternating current. When two capacitors and a small amount of resistors are used, the short power supply and short ground protection of the excitation output port of the vehicle controller is realized, and the reliability of the vehicle motor controller is increased at a relatively low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1A schematic diagram of the circuit structure of an excitation drive protection circuit of a rotary transformer provided by the present invention;

[0020] Figure 2 A schematic diagram of the circuit structure of the excitation drive protection circuit of the rotary transformer of the first variation provided by the present invention;

[0021] Figure 3 A schematic diagram of the circuit structure of the excitation drive protection circuit of the rotary transformer of the second variation provided by the present invention;

[0022] Figure 4 A schematic diagram of the circuit structure of an excitation drive protection circuit of a rotary transformer according to a third variation provided by the present invention.

[0023] Among them, 1 represents a filter, 2 represents a first input port, 3 represents a first output port, 4 represents a second input port, and 5 represents a second output port. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] It should be noted that the terms "including" and "having" and any variations thereof in the embodiments of the present invention and the accompanying drawings are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device including a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products or devices.

[0026] The embodiments of this specification disclose a rotary transformer excitation drive protection circuit, which is described in detail below.

[0027] The following is combined with Figure 1 To Attachment Figure 4 The circuit structure of an excitation drive protection circuit of a rotary transformer provided by the present invention is described in detail. Figure 1 A circuit structure diagram of an excitation drive protection circuit of a rotary transformer provided by the present invention is shown in FIG. Figure 1As shown, the excitation drive protection circuit of the rotary transformer provided by the present invention may first include two operational amplifiers, namely a first operational amplifier U1A and a second operational amplifier U1B, which are used to amplify the excitation signal emitted by the decoding chip. The protection circuit also includes a filter 1, a first capacitor C1, a second capacitor C2, a third capacitor C3, a fourth capacitor C4, and a fifth capacitor C5; a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, and a tenth resistor R10.

[0028] The specific circuit connection relationship between the components is described below. Figure 1 As shown, in the protection circuit, the non-inverting input terminal of the first operational amplifier U1A is connected to a reference voltage source of the first amplitude, the inverting input terminal of the first operational amplifier U1A is respectively connected to one end of the first resistor R1, one end of the second resistor R2 and one end of the third capacitor C3, the other end of the first resistor R1 is connected to an excitation signal input terminal of the second amplitude, the positive power supply terminal of the first operational amplifier U1A is connected to a voltage source of the third amplitude, the negative power supply terminal of the first operational amplifier U1A is grounded, and the output terminal of the first operational amplifier U1A is respectively connected to one end of the third resistor R3 and one end of the fourth resistor R4; the other end of the fourth resistor R4 is respectively connected to the other end of the resistor R2 and the other end of the third capacitor C3.

[0029] In the present invention, the excitation signal input terminal EXC and It can be an excitation signal sent by a decoding chip. In a specific embodiment, the reference voltage source of the first amplitude can be a voltage source of 4.28V, and the third amplitude voltage source can be a voltage source of +15V.

[0030] like Figure 1 As shown, one end of the first capacitor C1 is connected between the positive power supply terminal of the first operational amplifier U1A and the voltage source of the third amplitude, and the other end of the first capacitor C1 is grounded; the non-inverting input terminal of the second operational amplifier U1B is connected to the reference voltage source of the first amplitude, and the inverting input terminal of the second operational amplifier U1B is respectively connected to one end of the fifth resistor R5, one end of the seventh resistor R7 and one end of the fifth capacitor C5; the output terminal of the second operational amplifier U1B is respectively connected to one end of the sixth resistor R6 and one end of the eighth resistor R8, and the other end of the sixth resistor R6 is respectively connected to the other end of the fifth resistor R5 and one end of the seventh resistor R7.

[0031] The positive power supply terminal of the second operational amplifier U1B is connected to a positive voltage source of a fourth amplitude, the negative power supply terminal of the second operational amplifier U1B is grounded, and the output terminal of the second operational amplifier U1B is connected to a negative voltage source of a fifth amplitude;

[0032] The other end of the third resistor R3 is connected to the first input port 2 of the filter 1, the other end of the eighth resistor R8 is connected to the second input port 4 of the filter 1, the first output port 3 of the filter 1 is connected to one end of the second capacitor C2, and the second output port 5 of the filter 1 is connected to one end of the fourth capacitor C4; the other end of the second capacitor C2 is used as the first excitation signal output end; the other end of the fourth capacitor C4 is used as the second excitation signal output end; the other end of the second capacitor C2 is connected to one end of the tenth resistor R10, the other end of the fourth capacitor C4 is connected to one end of the ninth resistor R9, and the other end of the ninth resistor R9 is connected to the other end of the tenth resistor R10 and then grounded. In this protection circuit, in terms of numerical value, the second amplitude is smaller than the first amplitude, and the first amplitude is smaller than the third amplitude.

[0033] In the protection circuit provided by the present invention, after the excitation signal is amplified and transformed by the operational amplifier circuit, a sine wave with a phase difference of 180 degrees from the original excitation signal is obtained, which serves as the input excitation signal of the resolver transformer. Figure 1 The capacitors C2 and C4 in the circuit block direct current and pass alternating current. The DC component of the loop is isolated by the corresponding capacitors, thereby reducing the loop current and achieving the protective effect of limiting the current when the port is short-circuited to the ground. Similarly, when EXC+ or EXC- is short-circuited to the power supply, the DC component of the corresponding loop current is isolated by the corresponding capacitors, which also achieves the protective effect of limiting the current when the port is short-circuited. At the same time, it should be noted that Figure 1 In the figure, resistor R3 and resistor R8 can be used as current limiting resistors, connected in series in the corresponding branch circuit to limit the current size of the branch. In practical applications, the resistance of resistor R3 or resistor R8 cannot be too large, otherwise it may affect the excitation current of the rotary transformer. The specific resistance value can be set according to the actual use scenario, and the present invention does not limit the specific resistance value. The technical solution of the present invention makes full use of the conduction characteristics of capacitors that block direct current and pass alternating current. When two capacitors and a small amount of resistors are used, short power supply and short ground protection of the excitation output port of the vehicle controller are realized, and the reliability of the vehicle motor controller is increased at a relatively low cost.

[0034] based on Figure 1 The circuit structure of this specification also provides several technical solutions for variations of the circuit, which are described below.

[0035] As mentioned above, the third resistor R3 and the eighth resistor R8 can be used as current limiting resistors. Figure 2 As shown, Figure 2 The circuit structure diagram of the excitation drive protection circuit of the rotary transformer of the first variant provided by the present invention is shown in FIG. Figure 2In the embodiment, the third resistor R3 is a first equivalent resistor obtained by connecting the eleventh resistor R11 and the thirteenth resistor R13 in parallel, and a second equivalent resistor obtained by connecting the twelfth resistor R12 and the fourteenth resistor R14 in parallel in series. That is, in this embodiment, the third resistor R3 is replaced by four resistors R11, R12, R13 and R14, which facilitates flexible adjustment of the resistance value. Similarly, Figure 2 As shown, the eighth resistor R8 is obtained by connecting the fifteenth resistor R15 and the seventeenth resistor R17 in parallel to form a third equivalent resistor, and the fourth equivalent resistor R8 is obtained by connecting the sixteenth resistor R16 and the eighteenth resistor R18 in parallel to form a fourth equivalent resistor in series. In this solution, by reasonably adjusting the resistance values ​​of R11, R12, R13, R14, R15, R16, R17, and R18, when the excitation output is short-circuited to the ground or short-circuited to the power supply, the output current can be controlled within a certain range, thereby realizing the port protection of the excitation output of the vehicle motor controller.

[0036] In an optional embodiment, Figure 3 or Figure 4 As shown, the other end of the second capacitor C2 is connected to one end of the first inductor L1, and the other end of the first inductor L1 is used as the first excitation signal output end. In an optional embodiment, the other end of the fourth capacitor C4 is connected to one end of the second inductor L2, and the other end of the second inductor L2 is used as the second excitation signal output end.

[0037] Those skilled in the art can understand that the accompanying drawings are only schematic diagrams of an embodiment, and the modules or processes in the accompanying drawings are not necessarily required to implement the present invention.

[0038] Those skilled in the art can understand that the modules in the device in the embodiment can be distributed in the device in the embodiment according to the description of the embodiment, or can be changed accordingly and located in one or more devices different from the embodiment. The modules in the above embodiment can be combined into one module, or can be further divided into multiple sub-modules.

[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An excitation drive protection circuit for a rotary transformer, characterized in that: include: A first operational amplifier U1A, a second operational amplifier U1B, a filter (1), a first capacitor C1, a second capacitor C2, a third capacitor C3, a fourth capacitor C4, and a fifth capacitor C5; a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, and a tenth resistor R10; wherein: The non-inverting input terminal of the first operational amplifier U1A is connected to a reference voltage source of a first amplitude, the inverting input terminal of the first operational amplifier U1A is respectively connected to one end of the first resistor R1, one end of the second resistor R2 and one end of the third capacitor C3, the other end of the first resistor R1 is connected to an excitation signal input terminal of a second amplitude, the positive power supply terminal of the first operational amplifier U1A is connected to a voltage source of a third amplitude, the negative power supply terminal of the first operational amplifier U1A is grounded, the output terminal of the first operational amplifier U1A is respectively connected to one end of the third resistor R3 and one end of the fourth resistor R4; the other end of the fourth resistor R4 is respectively connected to the other end of the resistor R2 and the other end of the third capacitor C3; One end of the first capacitor C1 is connected between the positive power supply terminal of the first operational amplifier U1A and the voltage source of the third amplitude, and the other end of the first capacitor C1 is grounded; The non-inverting input terminal of the second operational amplifier U1B is connected to a reference voltage source of the first amplitude, and the inverting input terminal of the second operational amplifier U1B is respectively connected to one end of the fifth resistor R5, one end of the seventh resistor R7 and one end of the fifth capacitor C5; the output terminal of the second operational amplifier U1B is respectively connected to one end of the sixth resistor R6 and one end of the eighth resistor R8, and the other end of the sixth resistor R6 is respectively connected to the other end of the fifth resistor R5 and one end of the seventh resistor R7; The positive power supply terminal of the second operational amplifier U1B is connected to a positive voltage source of a fourth amplitude, the negative power supply terminal of the second operational amplifier U1B is grounded, and the output terminal of the second operational amplifier U1B is connected to a negative voltage source of a fifth amplitude; The other end of the third resistor R3 is connected to the first input port (2) of the filter (1), the other end of the eighth resistor R8 is connected to the second input port (4) of the filter (1), the first output port (3) of the filter (1) is connected to one end of the second capacitor C2, and the second output port (5) of the filter (1) is connected to one end of the fourth capacitor C4; the other end of the second capacitor C2 serves as a first excitation signal output end; the other end of the fourth capacitor C4 serves as a second excitation signal output end; the other end of the second capacitor C2 is connected to one end of the tenth resistor R10, the other end of the fourth capacitor C4 is connected to one end of the ninth resistor R9, and the other end of the ninth resistor R9 is connected to the other end of the tenth resistor R10 and then grounded.

2. The excitation drive protection circuit of the rotary transformer according to claim 1, characterized in that: The third resistor R3 is a first equivalent resistor obtained by connecting the eleventh resistor R11 and the thirteenth resistor R13 in parallel, and a second equivalent resistor obtained by connecting the twelfth resistor R12 and the fourteenth resistor R14 in parallel in series.

3. The excitation drive protection circuit of the rotary transformer according to claim 1, characterized in that: The eighth resistor R8 is a third equivalent resistor obtained by connecting the fifteenth resistor R15 and the seventeenth resistor R17 in parallel, and a fourth equivalent resistor obtained by connecting the sixteenth resistor R16 and the eighteenth resistor R18 in parallel in series.

4. The excitation drive protection circuit of the rotary transformer according to claim 1, characterized in that: The other end of the second capacitor C2 is connected to one end of the first inductor L1 , and the other end of the first inductor L1 is used as the first excitation signal output end.

5. The excitation drive protection circuit of the rotary transformer according to claim 1, characterized in that: The other end of the fourth capacitor C4 is connected to one end of the second inductor L2 , and the other end of the second inductor L2 is used as the second excitation signal output end.

6. The excitation drive protection circuit of the rotary transformer according to claim 1, characterized in that: The second amplitude is smaller than the first amplitude; and the first amplitude is smaller than the third amplitude.

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