Isolation PWM signal processing circuit for motor driving

Abstract

The utility model relates to an isolation PWM signal processing circuit used for motor driving, and the circuit comprises a signal isolation circuit which is used for carrying out ground isolation processing on a PWM signal; the signal blocking circuit is used for carrying out 0% duty ratio shielding and 100% duty ratio shielding on the PWM signals subjected to ground isolation processing; and the signal shaping circuit is used for shaping the PWM square waves passing through the signal blocking circuit to obtain standard PWM square waves, so that signal isolation is realized, and pure analog circuits with 0% and 100% duty ratios are shielded at the same time.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of signal processing, in particular to an isolated PWM signal processing circuit for motor driving. BACKGROUND

[0002] In the existing market motor driving, mainly in digital control, analog control, analog-digital hybrid control three types, in the military field, the requirement of duty cycle (pulse width modulation, referred to as PWM) control motor and control signal and power signal isolation, and no duty cycle loss problem, while shielding 0% and 100% duty cycle. The existing PWM open-loop motor control can realize signal isolation but generally cannot shield 0% and 100% duty cycle at the same time; in order to realize shielding 0% and 100% duty cycle at the same time, a small part of digital circuit is added, which cannot meet the pure analog requirement. CONTENT OF THE UTILITY MODEL

[0003] In order to overcome the problems in the related art, the utility model provides an isolated PWM signal processing circuit for motor driving which can realize signal isolation and shield 0% and 100% duty cycle at the same time.

[0004] In order to achieve the above purpose, the utility model provides an isolated PWM signal processing circuit for motor driving, which comprises:

[0005] A signal isolation circuit is used for ground isolation processing of the PWM signal.

[0006] A signal isolation circuit is used for ground isolation processing of the PWM signal.

[0007] A signal shaping circuit is used for shaping the PWM square wave after the signal isolation circuit to obtain a standard PWM square wave.

[0008] Preferably, the signal isolation circuit comprises a resistor R1 and a circuit U1, the resistor R1 is connected with the input pin 1 of the circuit U1, the signal isolation circuit is connected with the output pin 5 of the circuit U1, and the PWM signal is isolated and processed in the circuit U1 and then enters the signal isolation circuit through the output pin 5 of the circuit U1.

[0009] Preferably, the signal isolation circuit comprises a capacitor C2 and a resistor R2, one end of the capacitor C2 is connected with the signal isolation circuit, the other end is connected with the signal shaping circuit, the resistor R2 is connected with the resistor R2 in series and grounded, and is connected with the signal shaping circuit in parallel.

[0010] Preferably, the signal shaping circuit comprises a resistor R3, a circuit U2 and a resistor R5, one end of the resistor R3 is connected with the signal isolation circuit, the other end is connected with the circuit U2 and the resistor R5 which are connected in parallel with each other.

[0011] Preferably, the circuit U2 is an amplification circuit, the V+ end of the amplification circuit is connected with the resistor R4, the V- end of the amplification circuit is grounded, the V S+ end of the amplification circuit is connected with VCC, and the V S- end of the amplification circuit is connected with the ground end.

[0012] The technical scheme provided by the embodiment of the disclosure can include the following beneficial effects:

[0013] The PWM signal is subjected to isolation processing through the isolation circuit, and then subjected to shielding of 0% duty ratio and 100% duty ratio through the signal isolation direct current circuit, the PWM signal subjected to shielding is subjected to shaping by the signal shaping circuit, and is outputted as a standard PWM square wave, so that signal isolation is realized, and a pure analog circuit shielding 0% and 100% duty ratio is realized.

[0014] Other features and advantages of the present application will be described in detail in the following specific embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0015] The accompanying drawings are included to provide a further understanding of the present disclosure and constitute a part of the specification, and are used together with the following detailed description to explain the present disclosure, but do not constitute a limitation on the present disclosure. In the drawings:

[0016] Figure 1 is a structural schematic diagram of an isolation PWM signal processing circuit for motor driving;

[0017] Figure 2 is a circuit diagram of an isolation PWM signal processing circuit for motor driving. DETAILED DESCRIPTION

[0018] The exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present disclosure. Instead, they are merely examples of apparatuses and methods consistent with some aspects of the present disclosure as detailed in the appended claims.

[0019] It can be understood that "multiple" in the present disclosure means two or more, and other quantifiers are similar. The association relationship of "and / or" describing the associated objects means that there can be three relationships, for example, A and / or B can mean that there are three cases of A alone, A and B together, and B alone. The character " / " generally represents an "or" relationship between the associated objects before and after it. The singular forms "a", "said" and "the" are also intended to include the plural forms, unless the context clearly indicates otherwise.

[0020] It is further understood that the terms "first", "second", etc. are used to describe various information, but the information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other, and do not indicate a specific order or importance. In fact, the expressions "first", "second", etc. can be used interchangeably. For example, the first flag position set can also be referred to as the second flag position set, and similarly, the second flag position set can also be referred to as the first flag position set without departing from the scope of the present disclosure.

[0021] As shown in Figure 1 An isolation PWM signal processing circuit for motor driving, comprising:

[0022] A signal isolation circuit for ground isolation processing of the PWM signal; when the PWM signal for motor driving enters the signal isolation circuit for ground isolation processing, the noise is reduced;

[0023] As shown in Figure 2 The signal isolation circuit includes resistor R1 and circuit U1, the resistor R1 is connected with the input pin 1 of the circuit U1, the signal isolation circuit is connected with the output pin 5 of the circuit U1, the PWM signal enters the circuit U1 for isolation processing through the resistor R1, and then enters the signal isolation circuit through the output pin 5 of the circuit U1, the output pin 6 in the circuit U1 is connected with VCC, the output pin 4 is grounded, and the C pin is grounded; the PWM signal can be effectively processed, and the noise is reduced.

[0024] A signal isolation circuit for shielding 0% duty cycle and 100% duty cycle of the PWM signal processed by ground isolation; ensuring that 0% duty cycle and 100% duty cycle in the PWM signal cannot pass through the signal isolation circuit, completing the shielding of 0% duty cycle and 100% duty cycle;

[0025] The signal isolation circuit includes capacitor C2 and resistor R2, one end of the capacitor C2 is connected with the signal isolation circuit, the other end is connected with the signal shaping circuit, and the resistor R2 is connected in series with the resistor R2 and grounded and connected in parallel with the signal shaping circuit. After the PWM signal processed by the signal isolation circuit passes through C2 and R2, a PWM alternating signal with an equal duty cycle and an uncertain offset is generated on R2 by using the direct and alternating function of the capacitor, ensuring that 0% and 100% duty cycle cannot pass through, and completing the shielding of 0% and 100% duty cycle signals.

[0026] A signal shaping circuit for shaping the PWM square wave passing through the signal isolation circuit to obtain a standard PWM square wave.

[0027] The signal shaping circuit comprises a resistor R3, a circuit U2 and a resistor R5, one end of the resistor R3 is connected to a signal isolation circuit, and the other end is connected to the circuit U2 and the resistor R5 in parallel with each other. The PWM AC signal with an uncertain offset is shaped by the U2 into a standard PWM signal same as the input PWM, the signal shaping is completed, the signal isolation can be realized, and the 0% and 100% duty cycle pure analog circuits are shielded.

[0028] In another embodiment, the circuit U2 is an amplification circuit, a V+ end of the amplification circuit is connected to the resistor R4, a V- end of the amplification circuit is grounded, a V S+ end of the amplification circuit is connected to the VCC, and a V S- end of the amplification circuit is connected to the ground.

[0029] In addition, it should be noted that various specific technical features described in the above specific embodiments can be combined in any appropriate way without contradiction. In order to avoid unnecessary repetition, various possible combinations are not described again in the present disclosure.

[0030] Furthermore, various different embodiments of the present disclosure can also be combined in any appropriate way, as long as it does not deviate from the idea of the present disclosure, it should also be considered as disclosed in the present disclosure.

Claims

1. An isolated PWM signal processing circuit for driving an electric machine, characterized by The application relates to a PWM signal processing circuit. The PWM signal processing circuit comprises a signal isolation circuit, a signal direct-current elimination circuit and a signal shaping circuit which are sequentially connected. The signal isolation circuit is used for carrying out isolation treatment on a PWM signal. The signal direct-current elimination circuit is used for shielding 0% duty ratio and 100% duty ratio of the PWM signal which has been subjected to the isolation treatment of the signal isolation circuit. The signal shaping circuit is used for shaping the PWM square wave which has been subjected to the treatment of the signal direct-current elimination circuit to obtain a standard PWM square wave.

2. The isolated PWM signal processing circuit for motor drive according to claim 1, wherein The signal isolation circuit comprises a resistor R1 and a circuit U1, the resistor R1 is connected with an input pin 1 of the circuit U1, the signal direct-current elimination circuit is connected with an output pin 5 of the circuit U1, and the PWM signal enters the circuit U1 to be subjected to isolation treatment through the resistor R1 and then enters the direct-current elimination circuit through the output pin 5 of the circuit U1.

3. An isolated PWM signal processing circuit for driving an electric motor according to claim 1 or 2, characterized in that The signal direct-current elimination circuit comprises a capacitor C2 and a resistor R2, one end of the capacitor C2 is connected with the signal isolation circuit, the other end of the capacitor C2 is connected with the signal shaping circuit, the resistor R2 is connected with the resistor R2 in series and then grounded and is connected with the signal shaping circuit in parallel.

4. The isolated PWM signal processing circuit for motor drive according to claim 1 or 2, wherein The signal shaping circuit comprises a resistor R3, a circuit U2 and a resistor R5, one end of the resistor R3 is connected with the signal direct-current elimination circuit, the other end of the resistor R3 is connected with the circuit U2 and the resistor R5 which are connected in parallel with each other.

5. An isolated PWM signal processing circuit for driving an electric motor according to claim 4, wherein, The circuit U2 is an amplification circuit, a V+ end of the amplification circuit is connected with a resistor R4, a V- end of the amplification circuit is grounded, a VS+ end of the amplification circuit is connected with VCC, and a VS- end of the amplification circuit is connected with a grounding end.

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