阅读说明：本技术 保护装置 (Protective device ) 是由 古仲雄大 河合健司 于 2020-04-10 设计创作，主要内容包括：本发明提供一种保护装置,其是设置在具有多个绕组的同步电动机(12)和驱动同步电动机(12)的电动机驱动装置(10a)之间的保护装置(10b),具备：开闭装置(28),其切换电动机驱动装置(10a)与同步电动机(12)的连接和切断；动态制动电路(26),其具备电阻(Ru、Rv、Rw)、在开闭装置(28)和同步电动机(12)之间经由电阻(Ru、Rv、Rw)将多个绕组短路的开关(26u、26v、26w)；控制装置(30),其控制开闭装置(28)和动态制动电路(26)。控制装置(30)在控制动态制动电路(26)的开关(26u、26v、26w)来使多个绕组短路后,控制开闭装置(28)来将电动机驱动装置(10a)与同步电动机(12)的连接切换为切断。(The present invention provides a protection device (10b) provided between a synchronous motor (12) having a plurality of windings and a motor drive device (10a) that drives the synchronous motor (12), the protection device including: an opening/closing device (28) that switches between connection and disconnection of the motor drive device (10a) and the synchronous motor (12); a dynamic braking circuit (26) provided with resistors (Ru, Rv, Rw), and switches (26u, 26v, 26w) that short-circuit the plurality of windings between the switching device (28) and the synchronous motor (12) via the resistors (Ru, Rv, Rw); and a control device (30) for controlling the opening/closing device (28) and the dynamic braking circuit (26). The control device (30) controls the switches (26u, 26v, 26w) of the dynamic braking circuit (26) to short-circuit the plurality of windings, and then controls the switching device (28) to switch the connection between the motor drive device (10a) and the synchronous motor (12) to the disconnection.)

1. A protector provided between a synchronous motor having a plurality of windings and a motor drive device for driving the synchronous motor, the protector comprising:

an opening/closing device for switching connection and disconnection between the motor drive device and the synchronous motor;

a dynamic braking circuit including a resistor and a switch for short-circuiting the plurality of windings between the switching device and the synchronous motor via the resistor; and

a control device for controlling the opening/closing device and the dynamic braking circuit,

the control device controls the switch of the dynamic braking circuit to short-circuit the plurality of windings, and then controls the opening/closing device to switch the connection between the motor drive device and the synchronous motor to be disconnected.

2. The protection device of claim 1,

the dynamic braking circuit includes one or more resistors and one or more switches for each phase,

the control device controls the plurality of switches to short-circuit the plurality of windings via the plurality of resistors.

3. The protection device according to claim 1 or 2,

the dynamic braking circuit includes: a detector for detecting a voltage of the resistor or a current flowing through the resistor,

the control device determines whether or not the plurality of windings are short-circuited based on a detection signal of the detector, and controls the switching device to switch the connection between the motor drive device and the synchronous motor to be disconnected after determining that the plurality of windings are short-circuited.

4. A protection device according to any one of claims 1 to 3,

when an abnormality of the synchronous motor or the motor drive device is detected, the control device causes the dynamic braking circuit to short-circuit the winding.

Technical Field

The present invention relates to a protection device for protecting a synchronous motor and a motor drive device for driving the synchronous motor.

Background

As described in japanese patent No. 6285477, a dynamic braking circuit is widely used to bring a motor driven by a motor driving device into an emergency stop. The dynamic braking circuit is a circuit that converts rotational energy into joule heat by short-circuiting a plurality of windings of the motor via a resistor, thereby braking the rotation of the motor.

The resistance value of the resistor used in the dynamic braking circuit has a correlation with the braking force applied to the motor. If the resistance value is increased, the potential difference between the power lines of each phase at the time of short-circuit becomes large, and the potential difference may exceed the withstand voltage of the driving device including the inverter. Therefore, there is a problem that a resistance value suitable for protecting the motor cannot be selected.

Disclosure of Invention

The object of the invention is therefore: provided is a protection device capable of appropriately selecting the resistance value of a resistor used in a dynamic braking circuit while protecting a synchronous motor and a motor drive device.

An aspect of the present invention is a protection device provided between a synchronous motor having a plurality of windings and a motor drive device that drives the synchronous motor, the protection device including: an opening/closing device for switching connection and disconnection between the motor drive device and the synchronous motor; a dynamic braking circuit having a resistor and a switch for short-circuiting the plurality of windings between the switching device and the synchronous motor via the resistor; and a control device for controlling the opening/closing device and the dynamic braking circuit. The control device controls the switch of the dynamic braking circuit to short-circuit the plurality of windings, and then controls the opening/closing device to switch the connection between the motor drive device and the synchronous motor to be disconnected.

According to the present invention, it is possible to appropriately select the resistance value of the resistor used in the dynamic braking circuit while protecting the synchronous motor and the motor drive device.

The above objects, features, and advantages will be readily apparent from the following description of the embodiments with reference to the accompanying drawings.

Drawings

Fig. 1 is a diagram showing an example of the configuration of a motor drive system according to an embodiment.

Fig. 2 is a flowchart illustrating an operation of the protection device according to the embodiment.

Fig. 3 is a diagram showing another example of the configuration of the motor drive system according to the embodiment.

Fig. 4 is a diagram showing a configuration of a motor drive system according to modification 1.

Detailed Description

Hereinafter, the protection device of the present invention will be described in detail with reference to the accompanying drawings by referring to preferred embodiments.