Dynamic braking circuit of servo driver

Abstract

A dynamic braking circuit of a servo driver is characterized in that the input end of a triode control module is connected with a power supply and used for responding to a dynamic instruction, the input end of an output circuit is connected with the triode control module, and the output end of the output circuit is connected with a three-phase terminal of a servo motor; the dynamic braking circuit is connected between the triode control circuit and the output circuit, a silicon controlled rectifier control circuit, a braking resistor and a rectifier bridge circuit are arranged in the dynamic braking circuit, when a dynamic braking instruction is received, a triode is switched on, the primary side of a silicon controlled rectifier optocoupler PC1 is switched on, a signal is transmitted to the secondary side, a silicon controlled rectifier built in the secondary side is switched on, and the braking resistor is switched on. At the moment, a trigger electrode signal of the silicon controlled rectifier SCR1 is in a high level so as to be conducted, reverse electromotive force generated by rotation of the motor is rectified by the rectifier bridge and loaded at two ends of the brake resistor R1, and the brake resistor consumes energy through heating so as to achieve a dynamic brake effect.

Description

Technical Field

[0001] The utility model relates to a dynamic braking circuit of a servo driver, belonging to the field of servo drivers. Background Art

[0002] Servo drives are key devices widely used in the field of industrial automation. They are responsible for accurately controlling the speed and position of the motor. During the operation of the servo drive, in order to achieve rapid stopping or emergency braking, a mechanism that can quickly consume the kinetic energy of the motor is required. Existing braking methods usually rely on relays or inverters to achieve rapid braking, but both have certain problems.

[0003] For example, using a relay to short-circuit the UVW phases of the motor, thereby utilizing the reverse electromotive force generated by the motor's own rotation to quickly stop the motor, during the braking process, excessive current may cause arcing of the relay contacts, thus shortening the life of the relay; energy release is achieved by opening the lower bridge arm of the inverter, which may cause current to flow through the power semiconductors of the inverter during braking, thereby damaging the components. Utility Model Content

[0004] In view of the deficiencies in the prior art, the utility model aims to provide a servo drive dynamic braking circuit to solve the problems of excessive current, device damage and unstable braking control in the braking process in the prior art.

[0005] In order to achieve the above object, the utility model is implemented through the following technical solution: a servo drive dynamic braking circuit, the circuit comprising:

[0006] A transistor control circuit, wherein an input end of the transistor control circuit is connected to a power supply and is used to respond to dynamic instructions;

[0007] An output circuit, wherein an input end of the output circuit is connected to the transistor control circuit, and an output end of the output circuit is connected to a three-phase terminal of a servo motor;

[0008] A dynamic braking circuit is connected between the transistor control circuit and the output circuit, and the dynamic braking circuit internally comprises a thyristor control circuit, a braking resistor and a rectifier bridge circuit.

[0009] Furthermore, the transistor control circuit includes a plurality of transistors, and the transistors are divided into an upper bridge arm and a lower bridge arm in groups of two. The transistors are used to be turned on when a dynamic braking instruction is received, thereby triggering the thyristor control circuit.

[0010] Furthermore, the thyristor control circuit includes at least one thyristor optocoupler PC1 and at least one thyristor SCR1. When the primary side of the thyristor optocoupler PC1 is turned on, a signal is transmitted to the secondary side of the thyristor optocoupler PC1, thereby triggering the thyristor control circuit to turn on.

[0011] Furthermore, the conduction condition of the thyristor SCR1 is that the trigger pole signal is at a high level, and the signal is provided by the transistor control circuit.

[0012] Furthermore, a resistor R3 is provided between the gate and cathode of the thyristor SCR1, the anode of the thyristor SCR1 is connected to the resistor R2, the resistor R2 is a trigger current limiting resistor, the resistor R3 is a gate resistor, and the resistor R2 and the resistor R3 are used to prevent triggering and improve the anti-interference ability of the thyristor control circuit.

[0013] Furthermore, the rectifier bridge circuit is used to rectify the reverse electromotive force generated by the rotation of the motor and load it on both ends of the braking resistor. The reverse electromotive force is converted into electrical energy after passing through the rectifier bridge.

[0014] Furthermore, the braking resistor is connected between the thyristor control circuit and the rectifier bridge circuit, and the braking resistor converts electrical energy into thermal energy for consumption by generating heat.

[0015] Furthermore, the thyristor control circuit controls the thyristor SCR1 to be turned on through a weak current isolation signal, so as to consume the energy of the motor rotation on the resistor.

[0016] The beneficial effects of the utility model are:

[0017] When an operator uses a dynamic braking circuit of a servo drive, the dynamic braking circuit needs to be integrated between the existing transistor control circuit and the output circuit to ensure that all circuits are connected correctly. Then, relevant parameters and environment are configured in the control system of the servo drive before the operation can begin. When the circuit receives the dynamic braking command provided by the operator, the transistor in the transistor control circuit is turned on, which in turn causes the primary side of the thyristor optocoupler PC1 to be turned on, and the signal is transmitted to the secondary side. The built-in thyristor on the secondary side is turned on. At this time, the trigger pole signal of the thyristor SCR1 becomes a high level to turn on, allowing current to flow to the braking resistor. The reverse electromotive force generated by the rotation of the motor is converted into DC power through the rectifier bridge. The rectified power is loaded on both ends of the braking resistor. The braking resistor consumes energy by generating heat, rapidly reducing the speed of the motor, thereby realizing dynamic braking of the motor and achieving the purpose of rapid stopping. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Other features, objects and advantages of the present invention will become more apparent by reading the detailed description of non-limiting embodiments with reference to the following drawings:

[0019] Figure 1 This is a structural schematic diagram of a servo driver dynamic braking circuit of the utility model;

[0020] Figure 2 It is a circuit diagram of the dynamic braking circuit of the utility model.

[0021] The reference numerals are: 1, transistor control circuit; 2, output circuit; 3, dynamic braking circuit; 301, thyristor control circuit; 302, braking resistor; 303, rectifier bridge circuit. DETAILED DESCRIPTION

[0022] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further described below in conjunction with specific implementation methods.

[0023] Figure 1 This is a structural diagram of a servo driver dynamic braking circuit of the utility model. Figure 2 FIG. 1 is a circuit diagram of the dynamic braking circuit of the utility model. Figure 1 , Figure 2 As shown, the utility model provides a technical solution for a servo drive dynamic braking circuit, the circuit comprising:

[0024] A transistor control circuit 1, wherein the input end of the transistor control circuit 1 is connected to a power supply and is used to respond to dynamic instructions;

[0025] An output circuit 2, wherein the input end of the output circuit 2 is connected to the transistor control circuit 1, and the output end of the output circuit 2 is connected to the three-phase terminal of the servo motor;

[0026] The dynamic braking circuit 3 is connected between the transistor control circuit 1 and the output circuit 2 , and includes a thyristor control circuit 301 , a braking resistor 302 and a rectifier bridge circuit 303 .

[0027] In order to meet the requirement of rapid braking, the transistor control circuit 1 includes multiple transistors, which are divided into upper bridge arms and lower bridge arms in groups of two. The transistors are used to turn on when receiving a dynamic braking command, thereby triggering the thyristor control circuit 301.

[0028] In order to reduce electromagnetic interference, the thyristor control circuit 301 includes at least one thyristor optocoupler PC1 and at least one thyristor SCR1. When the primary side of the thyristor optocoupler PC1 is turned on, a signal is transmitted to the secondary side of the thyristor optocoupler PC1, thereby triggering the thyristor control circuit 301 to turn on.

[0029] In order to accurately control the braking process, the conduction condition of the thyristor SCR1 is that the trigger pole signal is at a high level, and the signal is provided by the transistor control circuit 1.

[0030] In order to improve the accuracy of the circuit, a resistor R3 is provided between the gate and cathode of the thyristor SCR1, the anode of the thyristor SCR1 is connected to the resistor R2, the resistor R2 is a trigger current limiting resistor, and the resistor R3 is a gate resistor. The resistor R2 and the resistor R3 are used to prevent triggering, thereby improving the anti-interference ability of the thyristor control circuit 301.

[0031] In order to realize energy conversion and consumption, the rectifier bridge circuit 303 is used to rectify the reverse electromotive force generated by the rotation of the motor and load it on both ends of the braking resistor 302. The reverse electromotive force is converted into electrical energy after passing through the rectifier bridge.

[0032] In order to achieve rapid braking, the braking resistor 302 is connected between the thyristor control circuit 301 and the rectifier bridge circuit 303 , and the braking resistor 302 converts electrical energy into heat energy for consumption by generating heat.

[0033] In order to achieve signal isolation, the thyristor control circuit 301 controls the thyristor SCR1 to turn on through a weak current isolation signal, so as to consume the energy of the motor rotation on the resistor.

[0034] When an operator uses a dynamic braking circuit of a servo drive, the dynamic braking circuit needs to be integrated between the existing transistor control circuit and the output circuit to ensure that all circuits are connected correctly. Then, relevant parameters and environment are configured in the control system of the servo drive before the operation can begin. When the circuit receives the dynamic braking command provided by the operator, the transistor in the transistor control circuit is turned on, which in turn causes the primary side of the thyristor optocoupler PC1 to be turned on, and the signal is transmitted to the secondary side. The built-in thyristor on the secondary side is turned on. At this time, the trigger pole signal of the thyristor SCR1 becomes a high level to turn on, allowing current to flow to the braking resistor. The reverse electromotive force generated by the rotation of the motor is converted into DC power through the rectifier bridge. The rectified power is loaded on both ends of the braking resistor. The braking resistor consumes energy by generating heat, rapidly reducing the speed of the motor, thereby realizing dynamic braking of the motor and achieving the purpose of rapid stopping.

[0035] The dynamic braking process of the present application is isolated by the thyristor optocoupler PC1, so that the weak point isolation signal is used to control the conduction of the thyristor SCR1, thereby realizing the consumption of the energy of the motor rotation on the braking resistor, avoiding the arc damage to the relay contacts caused by the instantaneous closure of the relay in the conventional device, and also avoiding the damage to the inverter module by the loop current generated by the inverter module to form a loop.

[0036] The above shows and describes the basic principles and main features of the utility model and the advantages of the utility model. For those skilled in the art, it is obvious that the utility model is not limited to the details of the above exemplary embodiments, and can be implemented in other specific forms without departing from the spirit or basic features of the utility model. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the utility model is limited by the attached claims rather than the above description, and it is intended to include all changes within the meaning and scope of the equivalent elements of the claims. Any figure mark in the claims should not be regarded as limiting the claims involved.

[0037] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A servo drive dynamic braking circuit, characterized in that: The circuit comprises: A transistor control circuit (1), wherein an input end of the transistor control circuit (1) is connected to a power supply and is used to respond to dynamic instructions; An output circuit (2), wherein an input end of the output circuit (2) is connected to the transistor control circuit (1), and an output end of the output circuit (2) is connected to a three-phase terminal of a servo motor; A dynamic braking circuit (3), the dynamic braking circuit (3) being connected between the triode control circuit (1) and the output circuit (2), the dynamic braking circuit (3) comprising a thyristor control circuit (301), a braking resistor (302) and a rectifier bridge circuit (303).

2. A servo drive dynamic braking circuit according to claim 1, characterized in that: The transistor control circuit (1) comprises a plurality of transistors, wherein the transistors are divided into an upper bridge arm and a lower bridge arm in groups of two, and the transistors are used to be turned on when a dynamic braking instruction is received, thereby triggering a thyristor control circuit (301).

3. A servo drive dynamic braking circuit according to claim 1, characterized in that: The thyristor control circuit (301) comprises at least one thyristor optocoupler PC1 and at least one thyristor SCR1. When the primary side of the thyristor optocoupler PC1 is turned on, a signal is transmitted to the secondary side of the thyristor optocoupler PC1, thereby triggering the thyristor control circuit (301) to turn on.

4. A servo drive dynamic braking circuit according to claim 3, characterized in that: The conduction condition of the thyristor SCR1 is that the trigger pole signal is at a high level, and the signal is provided by the transistor control circuit (1).

5. A servo drive dynamic braking circuit according to claim 4, characterized in that: A resistor R3 is provided between the gate and cathode of the thyristor SCR1, the anode of the thyristor SCR1 is connected to the resistor R2, the resistor R2 is a trigger current limiting resistor, the resistor R3 is a gate resistor, and the resistor R2 and the resistor R3 are used to prevent triggering, thereby improving the anti-interference capability of the thyristor control circuit (301).

6. A servo drive dynamic braking circuit according to claim 1, characterized in that: The rectifier bridge circuit (303) is used to rectify the reverse electromotive force generated by the rotation of the motor and load it onto the two ends of the brake resistor (302); the reverse electromotive force is converted into electric energy after passing through the rectifier bridge.

7. The servo drive dynamic braking circuit according to claim 1, characterized in that: The braking resistor (302) is connected between the thyristor control circuit (301) and the rectifier bridge circuit (303), and the braking resistor (302) converts electrical energy into thermal energy for consumption by generating heat.

8. The servo drive dynamic braking circuit according to claim 3, characterized in that: The thyristor control circuit (301) controls the thyristor SCR1 to conduct through a weak current isolation signal, so as to realize that the energy of the motor rotation is consumed on the resistor.

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