CN202004713U

CN202004713U - DC motor excitation monitoring device for DC motor

Info

Publication number: CN202004713U
Application number: CN2011201339679U
Authority: CN
Inventors: 他崇芬; 赵姜坤; 田东芳; 李建民
Original assignee: QUJING QIANKUN PAPER CO Ltd
Current assignee: QUJING QIANKUN PAPER CO Ltd
Priority date: 2011-04-29
Filing date: 2011-04-29
Publication date: 2011-10-05
Anticipated expiration: 2021-04-29

Abstract

The utility model discloses a DC motor excitation monitoring device. In the DC motor excitation monitoring device, a DC intermediate relay ZJ (9) is connected in parallel to the two ends of a DC motor excitation winding F (8), and a freewheel diode D (10) is inversely connected in parallel to the DC intermediate relay ZJ (9). In a control circuit, a pair of normally open contacts of the DC intermediate relay ZJ (9) and a coil of a time relay SJ (11) are connected in series to the two ends of a power supply. A pair of delayed-closed contacts of the time relay SJ (11) and the coil of an armature power control contactor KM1 (2) are connected in series to the two ends of the power supply. The DC motor excitation monitoring device can effectively prevent a DC motor from being galloped by loss of excitation, and fully ensures the safety of production equipment and personal safety.

Description

The excitation of direct current generator monitoring arrangement

Technical field

The utility model belongs to the excitation monitoring arrangement that prevents direct current machine " driving ", especially utilize the switching of exciting current to control that armature gets, dead electricity (is that excitation winding gets, armature just powers on, if the excitation winding dead electricity, armature is with regard to dead electricity) prevent that direct current machine from the excitation monitoring arrangement technical field of structures of " driving " taking place because of loss of excitation.

Background technology

Direct current machine has good speed adjusting performance, speed-regulating range width, precision height, flatness are good and easy to adjust, also have higher overload capacity and good starting, braking ability, so direct current machine is extensively applied to require the electric drive of width speed adjustable range and the automatic control system that property requires.Direct current machine has two kinds of separate excitation and self-excitations by excitation mode classification, and self-excitation is applied to low-power machine more, and separate excitation be used for more in, heavy-duty motor.Separately excited DC machine is used more, and its speed regulating method has three kinds: change the speed governing of armature supply voltage, the speed governing of armature circuit series resistor, weak-magnetic speed-regulating.In these three kinds of methods, the speed governing of change armature voltage mode is level and smooth, hardness is higher, speed good stability during load variations, and no matter underloading is still heavily loaded, and speed adjustable range is identical, thereby adopts more.The direction of rotation of direct current machine is by the sense of current of armature winding and the decision of the excitation winding sense of current, as long as change one of them sense of current, the direction of rotation of motor just changes, therefore two kinds of methods that change motor steering are arranged: 1. the sense of current changes in the armature winding, the electric power polarity that just is applied on the armature winding changes, the exciting current direction is constant, and the excitation field direction remains unchanged.2. the sense of current changes in the excitation winding, the excitation field direction is changed and the armature supply direction is constant, easily produces excitation power supply extinction tests when this method is in operation the switched energization sense of current.Yet in practice, in, high power DC electric machine is commonly used changes the speed governing of armature supply voltage, adopts separate excitation for magnetic, the turning to by changing the sense of current change in the excitation winding of motor.This governing system adopts the current double closed-loop speed governing, be equipped with the smoothing reactor of enough inductance values, be actually by current source supply, this makes motor characteristic that change take place, special its loss of excitation, " driving " phenomenon promptly can appear in loss of excitation, and it is according to being: n=(U-IaRa)/(Ce φ), the supply power voltage of U in the formula---motor; Ia---armature supply; Ra---armature resistance; φ---motor gas-gap magnetic flux, loss of excitation φ just drops sharply to 2% of rated value---and 4%, rotation speed n will be increased sharply, i.e. " driving ".The direct current machine loss of excitation is that the serious accident in the dc trailing system must be taken precautions against.

Summary of the invention

The purpose of this utility model in order to overcome defective that above-mentioned prior art exists and not enough in preventing that the direct current machine loss of excitation from causing that the serious accident in the dc trailing system provides a kind of energy automatic monitoring motor excitation, can be cut off the excitation of direct current generator monitoring arrangement that the armature power supply prevents that " driving " takes place just immediately when excitation is lost.

The purpose of this utility model is achieved by the following technical solution.

The excitation of direct current generator monitoring arrangement, the utility model comprises armature power supply control contactor KM1, direct current intermediate relay ZJ, sustained diode, time relay sj, the direct current intermediate relay ZJ is connected in parallel on excitation of direct current generator winding F two ends, and sustained diode is connected in reverse parallel on the direct current intermediate relay ZJ; In control loop, a pair of normally opened contact of direct current intermediate relay ZJ and the coil series connection of time relay sj are at both ends of power, and the coil series connection of a pair of timing closing contact of time relay sj and armature power supply control contactor KM1 is at both ends of power.

Armature just may get when whenever no matter the utility model had only excitation to exist; If there is not the excitation armature just not have electric current to pass through, thereby controlled " driving " that direct current machine produces because of loss of excitation.

The beneficial effects of the utility model are to prevent effectively that direct current machine from because of " driving " phenomenon that loss of excitation produces, fully ensureing production equipment and personal safety.

The utility model technology is described further as embodiment below in conjunction with Fig. 1, Fig. 2.

Description of drawings

Fig. 1 is the utility model main circuit structure schematic diagram;

Fig. 2 is a control loop device syndeton schematic diagram.

The utility model is made up of 11 devices, and its label is:

1, insurance; 2, armature power supply control contactor; 3, reactor; 4, armature rectifier; 5, armature insurance; 6, direct current machine armature; 7, field rectifier; 8, magnet exciting coil; 9, direct current auxiliary relay; 10, fly-wheel diode; 11, the time relay.

Embodiment

As Fig. 1, Fig. 2, the excitation of direct current generator monitoring arrangement, the utility model comprises armature power supply control contactor KM1 (2), direct current intermediate relay ZJ (9), sustained diode (10), time relay sj (11), direct current intermediate relay ZJ (9) is connected in parallel on excitation of direct current generator winding F (8) two ends, and sustained diode (10) is connected in reverse parallel on the direct current intermediate relay ZJ (9); In control loop, the coil series connection of a pair of normally opened contact of direct current intermediate relay ZJ (9) and time relay sj (11) is at both ends of power, and a pair of timing closing contact of time relay sj (11) and the coil series connection of armature power supply control contactor KM1 (2) are at both ends of power.

Each component function of the utility model and occupation mode are:

Insurance 1 is used for the protection of major loop;

Armature power supply control contactor 2 control armature rectifier power sources, coil voltage AC220V;

Reactor 3 is used to reduce the pulsation of rectifier power source;

Armature rectifier 4 adopts silicon controlled rectifier to provide DC power supply for armature.

Armature insurance 5 protection armatures;

The power source of armature 6 motors (electric energy is converted into the output point of mechanical energy);

Field rectifier 7 provides DC power supply for magnet exciting coil;

Generate an electromagnetic field after magnet exciting coil 8 energisings;

The electric pressure that direct current auxiliary relay 9 these relay coils are adopted should equate with exciting voltage, its effect be monitor excitation have or not model: DZ-31B DC220v;

Fly-wheel diode 10 fly-wheel diodes are connected in reverse parallel in auxiliary relay coil two ends, and its effect is that the auxiliary relay coil is frequently opened, stopped damaging to protection because of motor.Specification: 1N4007;

The time relay 11 coil voltages are AC220V.

The concrete Connection Step of the utility model:

(1) direct current auxiliary relay coils from parallel connection of coils is connected on the two ends of motor excitation; (2) fly-wheel diode oppositely is attempted by auxiliary relay coil two ends; (3) in control loop, a pair of normally opened contact of direct current auxiliary relay and the coil series connection of the time relay are at both ends of power, and a pair of timing closing contact of the time relay and the series connection of armature power supply control contactor coil are at both ends of power.Monitor excitation by the direct current auxiliary relay in the utilization process, if there is not excitation, armature must not be electric, thereby avoid the generation of " driving ".

Claims

1. excitation of direct current generator monitoring arrangement, it is characterized in that, comprise armature power supply control contactor KM1 (2), direct current intermediate relay ZJ (9), sustained diode (10), time relay sj (11), direct current intermediate relay ZJ (9) is connected in parallel on excitation of direct current generator winding F (8) two ends, and sustained diode (10) is connected in reverse parallel on the direct current intermediate relay ZJ (9); In control loop, the coil series connection of a pair of normally opened contact of direct current intermediate relay ZJ (9) and time relay sj (11) is at both ends of power, and a pair of timing closing contact of time relay sj (11) and the coil series connection of armature power supply control contactor KM1 (2) are at both ends of power.