CN101420122A - Protection circuit for protecting groove insulation of motor winding - Google Patents

Protection circuit for protecting groove insulation of motor winding Download PDF

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Publication number
CN101420122A
CN101420122A CNA2008102040277A CN200810204027A CN101420122A CN 101420122 A CN101420122 A CN 101420122A CN A2008102040277 A CNA2008102040277 A CN A2008102040277A CN 200810204027 A CN200810204027 A CN 200810204027A CN 101420122 A CN101420122 A CN 101420122A
Authority
CN
China
Prior art keywords
motor
voltage
protective circuit
piezo
insulation
Prior art date
Application number
CNA2008102040277A
Other languages
Chinese (zh)
Inventor
张良基
Original Assignee
上海电器科学研究所(集团)有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 上海电器科学研究所(集团)有限公司 filed Critical 上海电器科学研究所(集团)有限公司
Priority to CNA2008102040277A priority Critical patent/CN101420122A/en
Publication of CN101420122A publication Critical patent/CN101420122A/en

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Abstract

The invention relates to a protective circuit used for protecting machine winding slot insulation to meet motor insulation protection. The protective circuit is characterized in that three voltage dependent resistors are connected on a binding post of a motor in parallel; when the motor generates high voltage during process of starting and outage, the voltage dependent resistors can 'puncture' if peak value of the high voltage exceeds nominal voltage of the voltage dependent resistors, thereby generating protection effect to the motor winding. The connection method of the protective circuit is as follows: U phase is connected with R1, V phase is connected with R2, and W phase is connected with R3. In the protective circuit, the voltage dependent resistors connected in parallel can be connected with an outlet terminal of control equipment.

Description

A kind of protective circuit of protecting groove insulation of motor winding

Technical field

The present invention relates to a kind of protective circuit of protecting groove insulation of motor winding, belong to technical field of motors.

Technical background

Motor in use slot liner often damages, and especially often breakdown near the slot liner of notch, product both domestic and external is all like this.By analysis, mainly contain following two aspect reasons:

1) because motor is an inductive load, when motor cut off the power supply, its energy can not suddenly change.Energy stored is:

W M = 1 2 L i 2

L is a motor inductance in the formula, the transient current when i is outage.

Especially present contactor breaking capacity improves greatly, when the electric current that flows through motor in the moment that reaches peak value, the contactor disjunction, this moment motor inductance energy reach maximum.

Simultaneously, because motor exists distributed capacitance to the cable between the control device, therefore when motor cut off the power supply, the energy of inductance will be converted to the energy of electric capacity:

W E = 1 2 C U 2 That is: 1 2 L i 2 = 1 2 C U 2

C is the capacitance of distributed capacitance in the formula.

Because distributed capacitance C is very little, therefore can produce higher voltage, this voltage just may make the electrical machine insulation puncture, especially owing to being subjected to following 2) effect of described electromagnetism tension force makes easier puncture of slot liner of the notch that has been damaged.

Certainly, because the motor winding also exists resistance, so the energy of inductance can not all convert the energy of electric capacity to, but the high voltage that produces is very important.The high voltage of analysis to generation arranged, and its peak value can reach more than 7 times of motor rated voltage.

2) for the crane motor of cargo winch motor, building and the boats and ships of the motor, particularly Fraquent start of frequent starting, metallurgical electric machines for roller etc.When starting, motor flows through bigger starting current, produces bigger electromagnetism tension force.This electromagnetism tension force makes motor winding overhang generation radial motion.Under the often lasting effect of electromagnetism tension force, motor is destroyed easily near the insulation of notch, voltage breakdown takes place or burn.Especially the few motor of number of poles, its end is longer, and starting current is bigger, and electromagnetism tension force is also bigger during starting, therefore the easier insulation damages that makes notch.

Summary of the invention

The object of the present invention is to provide a kind of protective circuit of protecting groove insulation of motor winding; destroy winding insulation with the high voltage that prevents from starting and power process, to produce when motor; thereby prolong the useful life of motor, the accident of avoiding motor in use to take place simultaneously because of insulation damages.

For achieving the above object; technical scheme of the present invention is; on the binding post of motor and connect three piezo-resistances; when motor the starting and power process in produce high voltage the time; as long as its peak value surpasses the nominal voltage of piezo-resistance; piezo-resistance promptly can " puncture ", thereby the motor winding is produced protective effect.

Beneficial effect of the present invention: for the motor of frequent starting, the cargo winch motor of Fraquent start particularly, the crane motor of building and boats and ships, metallurgical electric machines for roller are when starting, motor flows through bigger starting current, produces bigger electromagnetism tension force.This electromagnetism tension force makes motor winding overhang generation radial motion.Under the often lasting effect of electromagnetism tension force, motor is destroyed easily near the insulation of notch, voltage breakdown takes place or burn.Especially the few motor of number of poles, its end is longer, and starting current is bigger, and electromagnetism tension force is also bigger during starting, therefore the easier insulation damages that makes notch.

Below in conjunction with drawings and Examples technical scheme of the present invention is made comparisons and to explain.

Description of drawings

Fig. 1 is a protective circuit schematic circuit of the present invention.

Embodiment

With reference to Fig. 1, this is a protective circuit schematic circuit of the present invention.

As shown in the figure, in U, V, W three-phase winding loop, seal in piezo-resistance R1, R2, R3 respectively, form and the access node structure.If the nominal voltage of piezo-resistance is 630V, when motor had high voltage to produce in starting and power process, as long as its peak value surpasses the nominal voltage 630V of piezo-resistance, piezo-resistance promptly can " puncture ", thereby the motor winding is produced protective effect; When high-tension peak value was lower than the nominal voltage of piezo-resistance, piezo-resistance was in " " state, electric motor normal working.

Because motor connecting cartridge is less, therefore, and the piezo-resistance that connects also can be connected on the outlet terminal of control appliance.If motor has several speed levels, as long as each speed level all has operating mode of across-the-line starting and outage, then all need on winding of each speed level and connect piezo-resistance, can both play a protective role with winding to each speed level.

Though the present invention describes with reference to the above embodiments; but those of ordinary skill in the art; will be appreciated that above embodiment is used for illustrating the present invention; should understand and wherein can make variations and modifications and do not break away from the present invention in a broad sense; so be not as limitation of the invention; as long as in connotation scope of the present invention, to the variation of above-described embodiment, the protection range that distortion all will fall into claim of the present invention.

Claims (2)

1, a kind of protective circuit of protecting groove insulation of motor winding, satisfy the motor insulation protection, it is characterized in that: this protective circuit is on the binding post of motor and connect three piezo-resistances: when high voltage that motor produces in starting and power process, as long as its peak value surpasses the nominal voltage of piezo-resistance, piezo-resistance promptly can " puncture ", thereby the motor winding is produced protective effect; Its connection is:
U R1, V R2, the w R3 that joins that joins that joins.
2. the protective circuit of protection groove insulation of motor winding as claimed in claim 1 is characterized in that: described protective circuit, and the piezo-resistance that connects can be connected on the outlet terminal of control appliance.
CNA2008102040277A 2008-12-04 2008-12-04 Protection circuit for protecting groove insulation of motor winding CN101420122A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CNA2008102040277A CN101420122A (en) 2008-12-04 2008-12-04 Protection circuit for protecting groove insulation of motor winding

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CNA2008102040277A CN101420122A (en) 2008-12-04 2008-12-04 Protection circuit for protecting groove insulation of motor winding

Publications (1)

Publication Number Publication Date
CN101420122A true CN101420122A (en) 2009-04-29

Family

ID=40630788

Family Applications (1)

Application Number Title Priority Date Filing Date
CNA2008102040277A CN101420122A (en) 2008-12-04 2008-12-04 Protection circuit for protecting groove insulation of motor winding

Country Status (1)

Country Link
CN (1) CN101420122A (en)

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN2086948U (en) * 1990-07-31 1991-10-16 天津市华通过程控制新技术应用研究所 Starting compensation control cabinet for low-voltage energy-saving cage motor
CN1135112A (en) * 1995-02-08 1996-11-06 西门子公司 Voltage-limiting and attenuation circuit for three-phase net work
US20010021116A1 (en) * 2000-03-09 2001-09-13 Siemens Ag. Converter motor with an energy recovery capability
CN2802829Y (en) * 2005-04-20 2006-08-02 李忠宏 Electronic balance compensation electric saver
CN101267179A (en) * 2008-04-23 2008-09-17 南京航空航天大学 High-speed brushless DC electromotor start/power generation system based on dual-level matrix frequency converter

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN2086948U (en) * 1990-07-31 1991-10-16 天津市华通过程控制新技术应用研究所 Starting compensation control cabinet for low-voltage energy-saving cage motor
CN1135112A (en) * 1995-02-08 1996-11-06 西门子公司 Voltage-limiting and attenuation circuit for three-phase net work
US20010021116A1 (en) * 2000-03-09 2001-09-13 Siemens Ag. Converter motor with an energy recovery capability
CN2802829Y (en) * 2005-04-20 2006-08-02 李忠宏 Electronic balance compensation electric saver
CN101267179A (en) * 2008-04-23 2008-09-17 南京航空航天大学 High-speed brushless DC electromotor start/power generation system based on dual-level matrix frequency converter

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Open date: 20090429

C02 Deemed withdrawal of patent application after publication (patent law 2001)