JPH06290967A - Protective device for forced ventilation type reactor - Google Patents

Abstract

PURPOSE:To provide a protective device quickly determining the absolute value of the allowable temperature of the temperature of a reactor coil, emitting a command to a protective circuit, interrupting a unit circuit and positively protecting a forced ventilation type reactor when a ventilating fan is stopped by trouble in the forced ventilation type reactor. CONSTITUTION:In a protective device for a forced ventilation type reactor composed of principal parts such as a temperature sensing element 10, a temperature sensor, a set temperature comparator, a circuit breaker, etc., the temperature sensing element 10 is fixed onto the surface of an insulating coating reactor coil on the intake port side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an induction motor as a VVVF.
The present invention relates to a protective device for a forced ventilation type reactor of a reactor or a chopper reactor used in a main circuit driven by a control device.

[0002]

2. Description of the Related Art In a forced-ventilation reactor protection device composed of main components such as a temperature detection element, a temperature detector, a comparator, and a circuit breaker, a forced-ventilation blower has conventionally failed or a blower power supply. When there is no cooling air due to a failure in the vehicle, or when there are multiple VVVF control unit units in the same formation as in the case of running operation of a vehicle, the other one unit must be cut before traveling. Occurs, the effective current of its own unit increases and the temperature of the reactor also rises. In such a case, a temperature detecting device is provided to prevent the reactor coil from being overheated and burned. Then, a temperature detecting element for the temperature detecting device is provided in the reactor coil on the exhaust side where the temperature of the normal reactor is highest, and when the temperature of the coil exceeds a predetermined set value, the temperature is detected and the regenerative brake is cut. Therefore, the overload is adjusted, or the circuit of the controller having the reactor is cut off to prevent the reactor from being burned.

[0003]

However, when the temperature detecting element is provided in the reactor coil on the exhaust side of the conventional reactor, there are the following drawbacks. Figure 3 below
Will be described with reference to. FIG. 3 is a curve diagram showing the relationship between the temperature rises on the intake side and exhaust side of the reactor coil and the operating time of the reactor. In the case of the aforementioned vehicle, the reactor coil uses a coil covered with an insulating material in order to protect it from dust and rainwater in the atmosphere. The allowable temperature of the coil is determined by the heat resistance of its insulation. (B) The temperature rise of the reactor coil is saturated when the cooling air is normal for 0 to t ₁ hour. At ₁ is the temperature of the reactor coil measured on the exhaust side. Bt ₁ is the temperature of the reactor coil measured on the inlet side. Ct ₁ is the temperature of the reactor coil measured by the resistance method. A At ₁ Bt ₁ = measured temperature difference.

(B) The time from t _{1 to} t _{2 is} the time to reach the average coil temperature allowable limit value measured by the resistance method. ΔAt ₂ is the temperature rise measured on the exhaust side at that time. ΔBt ₂ is the temperature rise measured on the inlet side at that time. Ct ₁ + ΔCt ₂ = Allowable coil temperature limit value by resistance method measurement. In this case At ₁ + ΔAt ₂ ,
Bt ₁ + ΔBt ₂ should have the same value as Ct ₁ + ΔCt ₂ , but since the temperature detecting element is attached to the surface of the insulator of the coil, a certain time lag occurs and the value finally becomes the same. (C) This indicates that ΔAt ₂ <ΔBt ₂ , and there is a drawback that the reaction of the protective device becomes slow when the temperature detection element is attached to the exhaust side to determine the set temperature.

[0005]

A temperature detecting element, which has been provided in a conventional exhaust side reactor coil, is provided in an intake side reactor coil. The set value of the predetermined temperature at that time is set to a predetermined value in consideration of the temperature difference between the intake side and the exhaust side. This is because the temperature rise per unit time when the blower is stopped due to a failure is larger than the temperature rise of the reactor coil on the intake side on the intake side.

[0006]

As described above, in the protective device for the forced draft type reactor which is constructed by providing the temperature detecting element on the inlet side surface of the insulated reactor coil as described above, as shown in FIG. The output of the air-side temperature detection element is detected as an absolute temperature by the temperature detector, and the temperature is compared by the set temperature comparator, and the protection circuit is activated by issuing a command at a temperature that does not lead to insulation damage of the reactor coil. That is, the reaction is quicker when the temperature detecting element is attached to the intake side than when it is attached to the exhaust side, so that the reactor can be reliably protected.

[0007]

EXAMPLES Examples will be described with reference to the drawings. FIG. 1 is an external view of a forced draft reactor. Reference numeral 1 is a reactor body, 2 is a blower, and 3 is a mounting foot. Figure 2 (a)
[Fig. 3] is a cross-sectional view of the reactor main body 1, and (b) is a right side view seen from the intake side. 4, 4a, 4b, 4c, 4d and 4e are reactor coils, and a ventilation gap 5 is provided between the coils of each layer. Reference numeral 6 is an insulating bolt for supporting the coil, 7 is an insulating supporter thereof, and 6a is a nut. Reference numeral 8 is an insulating inner cylinder for coil support, and 9 is an outer cylinder for coil protection. The reactor main body 1 has the above-described structure, and the temperature detecting element 10 is adhered and fixed to the surface of the insulated coil on the air intake side of the main body.

The cooling air flows in the direction of the arrow from the intake side and is discharged to the opposite side through the ventilation gap 5. Coils 4, 4a,
4b, 4c, 4d, 4e, etc. are insulated with polyamide tape, etc., and are strongly protected against the intrusion of dust and water. The temperature detecting element is detected as an absolute temperature by an external temperature detector 16 using a thermistor, a thermocouple or the like.

FIG. 4 shows an embodiment of a main circuit of one of a plurality of units of a vehicle driven by a VVVF inverter control device. 11 is a pantograph, 12 is a circuit breaker,
13 is a filter reactor, 14 is a VVVF inverter,
Reference numeral 15 is an induction motor, 16 is a temperature detector, 17 is a set temperature comparator, and 18 is a filter condenser. In the above circuit configuration, when the blower fails and ventilation is lost, the output of the temperature detection element 10 is guided to the temperature detector 16, the temperature is compared with the temperature of the set temperature comparator 17, and if it becomes higher than a predetermined temperature. The circuit breaker 12 is actuated to shut off the circuit and protect the filter reactor 13 from burning.

Further, in the case of a vehicle operating with a plurality of VVVF control devices in the same formation, if one other unit is cut in an accident and the vehicle runs, the effective current of the own unit increases and the temperature of the reactor coil increases. To rise. Even in such a case, it is easier to adjust the overload protection circuit by catching the temperature on the intake side, and the reactor can be surely protected from overheating and burning. Although the embodiment has been described for a vehicle, the same applies to an industrial one.

[0011]

When the temperature detecting element is attached to the surface of the insulating clothing reactor coil on the air intake side, ΔAt ₂ <ΔBt ₂ is satisfied when ventilation is lost due to a blower failure, so the output of the temperature detecting element is the temperature detector. Since the reaction speed displayed as an absolute temperature is fast, it is compared with the set temperature comparator in a speedy manner, and a protection command is issued to the protection circuit to reliably protect the reactor coil from burnout. Since the output of the temperature detecting element attached to the intake side can be set small by setting the output difference from the exhaust side by a predetermined value, the assumed absolute permissible temperature can be set with a margin, which is easy to adjust. Moreover, even if the ventilation direction is reversed, it can be protected.

[Brief description of drawings]

FIG. 1 is an outline view in which a blower is attached to a reactor body.

FIG. 2 (a) is a cross-sectional map of the reactor body of the embodiment of the present invention, and FIG. 2 (b) is a right side view seen from the intake side.

FIG. 3 is a relationship curve diagram between a reactor coil operating temperature rise on the intake side and an exhaust side of the reactor coil.

FIG. 4 is an example of a main circuit of one unit of a plurality of units of a vehicle driven by a VVVF inverter control device.

[Explanation of symbols]

 1 Reactor body 2 Blower 3 Mounting foot 4 Reactor coil 5 Gap for ventilation 6 Insulation bolt 6a Nut 7 Insulation support base 8 Insulation inner cylinder for coil support 9 Coil protection outer cylinder 10 Temperature sensing element 11 Pantograph 12 Circuit breaker 13 Filter reactor 14 VVVF inverter 15 Induction motor 16 Temperature detector 17 Set temperature comparator 18 Filter condenser 19 Inlet port 20 Exhaust port

Claims (1)

[Claims] 1. A temperature detecting element (10), a temperature detector (1
6), a set temperature comparator (17), a circuit breaker (12), and other forced parts that protect the forced ventilation type reactor from the temperature detection element (10) to the inlet (19) side of the reactor. Forced ventilation type reactor protection device, which is provided on the surface of the coil.