CN201758354U - A motor protection device - Google Patents

Abstract

The utility model discloses a motor protection device, which comprises an input terminal group, an output terminal group, a front-stage reactor composition, a rear-stage reactor composition and a three-phase supercapacitor. The composition of the front-stage reactor and the composition of the rear-stage reactor respectively have a horizontal axis, and the composition of the front-stage reactor and the composition of the rear-stage reactor are arranged at the vertical lower position of a three-phase supercapacitor, and the three-phase supercapacitor also has The axis in the horizontal direction. The utility model has the characteristics of eliminating power harmonics, reducing motor noise, vibration and calorific value, suppressing electromagnetic interference, accurately outputting sine wave voltage, eliminating torque jitter, and prolonging the life of the motor.

Description

A motor protection device

technical field

The utility model relates to the technical field of AC voltage stabilization and frequency conversion, in particular to a motor protection device. the

Background technique

At present, the most common equipment used in motor control is variable frequency drives. Frequency converters are used in almost all industrial occasions. Typical applications include: various pumps, air conditioning systems, elevators, elevators, conveyors, machine tools, and various new energy equipment. The working principle of the frequency converter is to control the speed of the motor by outputting the voltage of the pulse width modulation waveform to generate sinusoidal currents of different frequencies. the

The specific working principle of the frequency converter leads to the following three problems: power harmonic problem, shortened motor life problem, and electromagnetic interference problem. The hazards of three problems:

The power harmonic problem is generated by the rectifier at the front end of the frequency converter. Any AC-DC rectifier with a DC smoothing capacitor will generate different degrees of harmonic current problems when it is working. The harm of harmonic ground current is that when it flows into the public grid, it will generate harmonic voltage (Ohm's law) under the action of grid impedance, which will cause grid voltage waveform distortion, thereby disturbing other equipment on the grid. In addition, high-frequency harmonics As current travels through cables and transformers, it results in increased electrical energy losses. Due to various problems caused by harmonics, the power supply department has put forward restrictions on the harmonic current generated by users. The international standard is IEEE519, and the domestic standard is GB14549. the

The problem of shortening the life of the motor is caused by the PWM waveform voltage output by the variable frequency. The PWM waveform has a high frequency. These high-frequency voltage components lead to increased motor loss (causing the motor to overheat), excessive bearing leakage current (burning the bearing), Problems such as overshoot voltage at the motor end (breakdown of the insulation layer of the motor winding), these problems seriously shorten the life of the motor. Especially when the driver is far away from the motor (for example, more than 100M), the overshoot voltage will reach more than twice the normal voltage, which poses a serious threat to the winding insulation of the motor. the

The problem of electromagnetic interference includes two aspects. One is that the frequency converter injects electromagnetic interference into the power grid. This interference is different from harmonic current. It has a higher frequency and is generally called radio frequency interference. This interference will interfere with other equipment on the grid, and at the same time, it will generate radiation that interferes with nearby electronic equipment. Another kind of interference is generated by the PWM waveform voltage output by the inverter. When the PWM voltage is transmitted on the drive cable connecting the inverter and the motor, it will generate extremely strong electromagnetic interference radiation. This electromagnetic interference radiation will affect other nearby electronic equipment. form interference. the

Utility model content

The purpose of this utility model is to provide a motor protection device to solve defects such as power harmonics, shortened motor life, and electromagnetic interference caused by the application of traditional frequency converters in the prior art. the

The technical problem solved by the utility model can be realized by adopting the following technical solutions:

A motor protection device, comprising an input terminal group, an output terminal group, a front-stage reactor, a rear-stage reactor and a three-phase supercapacitor, characterized in that:

The rear-stage reactor is connected to the front-stage reactor, the three-phase supercapacitor is connected to the rear-stage reactor, the input terminal group is connected to the front-stage reactor, the output terminal group is connected to the rear-stage reactor, and the A three-phase supercapacitor has a horizontal axis, and the front-stage reactor composition and the rear-stage reactor composition also have horizontal axial directions, and the front-stage reactor composition and the rear-stage reactor composition are set in a three-phase supercapacitor The vertical lower position of the capacitor. the

The motor protection device of the utility model includes input terminal group, output terminal group, front-stage reactor composition, rear-stage reactor composition and a three-phase supercapacitor, which can eliminate electric power harmonics, reduce motor noise, vibration and calorific value , can suppress electromagnetic interference, accurately output sine wave voltage, eliminate torque jitter, and prolong the life of the motor. the

Description of drawings

Readers will have a clearer understanding of various aspects of the utility model after reading the specific implementation of the utility model with reference to the accompanying drawings. in:

Fig. 1 is a three-dimensional schematic diagram of the main structure of the motor protection device of the present invention;

Fig. 2 is a three-dimensional schematic diagram of the composition of the front-stage reactor and the composition of the rear-stage reactor of the utility model. the

Explanation of main component symbols in the drawings

Input terminal group 11 Input terminals 111, 112, 113

Output terminal group 12 Output terminals 121, 122, 123

Front-stage reactor composition 13 First reactor 131

The second reactor 132 The third reactor 133

Post-stage reactor composition 14 fourth reactor 141

Fifth reactor 142 Sixth reactor 143

Three-phase supercapacitor 15 Iron core 161, 162, 163, 164, 165, 166

Silicon steel sheet 167

Resin board 17 Locking element 18

The first wire 21 The second wire 22

The first wire winding core length H

The second wire winding core length h

Detailed ways

The specific implementation manners of the present invention will be described in further detail below with reference to the accompanying drawings. the

As shown in FIG. 1 , the utility model includes an input terminal group 11 , an output terminal group 12 , a front-stage reactor composition 13 , a rear-stage reactor composition 14 and a three-phase supercapacitor 15 . The rear-stage reactor composition 14 is connected to the front-stage reactor composition 13, a three-phase supercapacitor 15 is connected to the rear-stage reactor composition 14, the input terminal group 11 is connected to the front-stage reactor composition 13, and the output terminal group 12 is connected to the rear-stage reactor. The first-stage reactor composition 14, the three-phase supercapacitor 15 has an axial direction in the horizontal direction, the front-stage reactor composition 13 and the rear-stage reactor composition 14 also have a horizontal axial direction, and the front-stage reactor composition 13 Composition 14 with a post-stage reactor is arranged vertically below a three-phase supercapacitor 15 . Through the above configuration, a better space saving effect can be achieved. the

In order to adapt to three-phase alternating current, as shown in Figure 1, the front-stage reactor composition 13 described in the utility model includes a first reactor 131, a second reactor 132 and a third reactor 133; the rear-stage reactor composition 14 Including a fourth reactor 141, a fifth reactor 142 and a sixth reactor 143; wherein, the first reactor 131, the second reactor 132, the third reactor 133, the fourth reactor 141, and the fifth reactor 142 Each of the sixth reactor 143 has an iron core. The first reactor 131, the second reactor 132 and the third reactor 133 all use wires of the same material and the same cross-sectional area to wind the iron core to achieve the same specification; the fourth reactor 141, the fifth reactor 142 and the sixth reactor The reactor 143 uses wire rods of the same material and the same cross-sectional area to wind the iron core to achieve the same specifications; wherein, the wire rods used by the first reactor 131, the second reactor 132 and the third reactor 133 are the same as the wire rods used by the fourth reactor 141, The wires used in the fifth reactor 142 and the sixth reactor 143 have the same material but different cross-sectional areas. Furthermore, in order to achieve a better effect, the iron core 161 of the first reactor 131, the iron core 162 of the second reactor 132 and the iron core 163 of the third reactor 133 have the same length; the fourth reactor 141 The iron core 164 of the fifth reactor 142 and the iron core 166 of the sixth reactor 143 have the same length; the lengths of the iron cores 161, 162, and 163 are greater than the lengths of the iron cores 164, 165, and 166; The aforementioned iron cores 161, 162, 163, 164, 165, 166 have the same material and the same cross-sectional area. In this embodiment, the input terminal set 11 further includes three input terminals 111 , 112 , 113 respectively connected to the first reactor 131 , the second reactor 132 and the third reactor 133 of the front-stage reactor composition 13 . The output terminal group 12 includes three output terminals 121 , 122 , and 123 , which are respectively connected to the fourth reactor 141 , the fifth reactor 142 and the sixth reactor 143 of the subsequent reactor assembly 14 . the

As shown in Figure 2, each iron core 161 (162, 163, 164, 165 or 166) is formed by stacking and combining a plurality of silicon steel sheets 167. The motor protection device of the present invention further includes a resin plate 17. In this embodiment, each reactor is provided with a pair of resin plates 17, so there are six pairs of resin plates 17, and each pair of resin plates 17 connects an iron core 161 (162, 163, 164, 165 or 166) are sandwiched therein, or other non-magnetic materials can also be utilized, for example replacing the aforementioned resin plate 17 with a stainless steel sheet, each pair of resin plates 17 (or stainless steel sheet) The iron core 161 ( 162 , 163 , 164 , 165 or 166 ) can be closely combined with the locking element 18 . the

As shown in FIG. 2 , the front-stage reactor composition 13 and the rear-stage reactor composition 14 respectively use the first wire 21 and the second wire 22 to wind the iron core 161 ( 162 , 163 , 164 , 165 or 166 ). In order to form different reactances, the cross-sectional area of the first wire 21 can be designed to be different from the cross-sectional area of the second wire 22. For example, the first wire 21 uses a round enameled wire, and the second wire 22 uses a flat enameled wire. limit. Moreover, in order to form reactances of different sizes, it is also possible to design the length H of the iron core wound with the first wire 21 in the front-stage reactor composition 13 to be greater than the length H of the iron core wound with the second wire 22 in the rear-stage reactor composition 14. h. In addition, the surface of each reactor is covered with insulation coating to protect the wires composed of each reactor from abrasion, moisture and oxidation. the

The above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of rights of the present invention; at the same time, the above description should be clear and implementable for those skilled in the art, so others without departing from the spirit disclosed by the present invention The completed equivalent changes or modifications shall be included in the scope of the claims of the application. the

Claims (10)

1. an electric motor protective device consists predominantly of input terminal group, lead-out terminal group, prime reactor composition, back level reactor composition and a three-phase electrochemical capacitance, it is characterized in that:

This back level reactor composition is connected to this prime reactor and forms;

This three-phase electrochemical capacitance is connected to this back level reactor and forms;

This input terminal group is connected to this prime reactor and forms;

This lead-out terminal group is connected to this back level reactor and forms; And

This prime reactor composition, back level reactor form and the three-phase electrochemical capacitance has the axial of horizontal direction all respectively, and this prime reactor is formed the vertical lower position that all is arranged on this three-phase electrochemical capacitance with back grade reactor composition.

2. according to the described electric motor protective device of claim 1, it is characterized in that: this prime reactor is formed and is comprised first reactor, second reactor and the 3rd reactor; This back level reactor is formed and is comprised the 4th reactor, the 5th reactor and the 6th reactor; And this first, second, third, fourth, the 5th and the 6th reactor has an iron core separately.

3. according to the described electric motor protective device of claim 2, it is characterized in that: each iron core is repeatedly to put be combined into by a plurality of silicon steel sheets.

4. according to the described electric motor protective device of claim 2, it is characterized in that: this electric motor protective device further comprises six pairs of resin plates, and each is folded in an iron core wherein resin plate.

5. according to the described electric motor protective device of claim 2, it is characterized in that: this electric motor protective device further comprises six pairs of stainless sheet steels, and each is folded in an iron core wherein stainless sheet steel.

6. according to the described electric motor protective device of claim 2, it is characterized in that: this prime reactor is formed use first wire rod and is twined iron core, and this back level reactor is formed use second wire rod and twined iron core.

7. according to the described electric motor protective device of claim 6, it is characterized in that: this first wire rod is identical wire rod with second wire rod.

8. according to the described electric motor protective device of claim 6, it is characterized in that: the wherein a kind of of this first wire rod and second wire rod is flat enamelled wire.

9. according to the described electric motor protective device of claim 6, it is characterized in that: the wherein a kind of of this first wire rod and second wire rod is circular enamelled wire.

10. according to the described electric motor protective device of claim 6, it is characterized in that: first wire rod twined the length of the length of iron core greater than second wire rod winding iron core in this back level reactor composition during this prime reactor was formed.

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