SU1107011A1 - Method of determination of winding temperature of electrical machine under load - Google Patents

Abstract

METHOD FOR DETERMINING TEMPERATURE OF WINDING OF ELECTRIC MACHINE UNDER LOADING by using a winding as a resistance thermometer, applying DC current to the operating current of the winding and measuring it, characterized in that, in order to improve accuracy, an auxiliary resistor of an auxiliary resistor is connected to the operating current of the auxiliary winding, in order to improve accuracy. DC current is passed, the difference between the DC voltage drops on the winding and the reference resistor is measured and, at a zero value of the voltage drop difference, to ) t current magnitude in both the winding circuit and the reference resistor circuit, find the winding resistance RQ according to the formula D Oo - y ovm -: g (L JOB / M where JP is the direct current value in the auxiliary circuit; 5, ., the resistance of the reference resistor;; 1s5km is the magnitude of the direct current, i.v.m, in the winding circuit of the machine, by which the desired temperature is determined.

Description

obmogspeck magpin ipph ;; : i5-gkh g: h - MlMeirr HGMepOffvm PPD -laif ytkgC; petk r-imi p then k l.

Itoosten state method onpe, ru: jifH and - the temperature of the winding of electric machines under load, so..pr1P1i ;; with imposition; and working G1bk (direct current and orci measuring

However, the known method possesses the required accuracy due to the error due to the low current and low load values; hh loli znachnyh noise interference.

The most: close to ILXi-mch; .chko1 support for the proposed iinjuiciTCH method 1) the determination of rcMntparvpbi the wounds of electric equipment 1 1 iio; i FiarpvTic, consisting of isp (eh ,. current

windings of 10-STANDING current and t: r (t 3meren AI. 2.

One; 1К (1 and this method did not possess the required accuracy due to the significant magnitude of the measuring current flowing through the winding: che.

The purpose of the invention is measuring accuracy.

PotaEle in i p i

what do you agree

the winding of the p-p tor aft t f 1 and Hf 1 pass LT TT I I1

inii i difference

i i i i j j and the resistor and nii11 t i

naiL i i inri differences

in € the first term to ih

so in jen 1 b hr and find matt IP and inr

formula

about om

where, is the magnitude and og rtj / HH-ii-c- current

on PS l omo g; ggs1b1Oi ltpp ;, R, - c) lrotinlo pp- o6pa4iKi; ioi.i

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Ojr ,. - Ilyich1Ia -: (KH) YNK) WG1 tg.lnn value about; fv | ki maPI 1b :, p: KO-opi) (L1, (1I |) TI; m;: om1o

The method is reasonably consistent; I turn on 1 D m oOMOTKv: Mashgl, GG1S: Nichite, an uy) h-i-shtstl 2. peiHcv; 3, measure -: - could: m pgkmo Gok, 1and

hochpik S POSTO n.chogo current, about: Mzzistor 6, variable resistor 7, hichpermetr 8, capacitor 9, source 1;) y; rrg, rnn {) voltage, measure i-j - 1 pan but weight.

Determination of the temperature of the previous one ;; r-ü; mm is carried out in the following way: l: l. in a way.

| U1r-: e; W; s Winding resistance I PS pre / UK :; Hmomu way osnonano to measure; . DC current in the circuit of the winding 1 and from the city of .k of the fall of the NPN POST-KYANNAYA current through the winding by means of the direct current; (H-o with H3-iieCTHiJM nagr11 :: - m on the yarn is almost completely absent, since the potential difference across the direct current at the terminals of the AC source 10 is zero. Thus, the proposed method of measuring the resistance of an electric machine winding but under load it is based on measuring the direct current from the direct current source in the winding circuit 1, measuring the DC voltage drop across the winding 1 using the zero method using the equilibrium indicator 1, determining the DC voltage drop on the reference resistor 6 according to the value of the direct current in the auxiliary circuit with a known resistance value of the resistor 6. The auxiliary circuit parameters (resistance value) are chosen in raKHNf mode, there is practically no variable component of the load current. current in the auxiliary circuit is produced with high accuracy. Under the condition of equilibrium, the voltage drops (conditionally - the equilibrium of the circuit), the resistance value of the fouling 1 is determined by the formula D Do RO - - where Jn is the value of hundred direct current in the auxiliary circuit; RO is the resistance value of the reference resistor; JORM DC current in the winding circuit 1. Thus, the proposed method of measuring the resistance of the winding of an electric machine is implemented by a balancing circuit with one or two DC sources. In this case, the balancing circuit must be additionally equipped with current meters both in the main circuit and in the cell. auxiliary branch x. The proposed method for measuring the temperature of the winding of an AC electric machine directly under load is changed. This resistance has the following advantages: high measurement accuracy, since the error due to the non-stability of the parameters of the measuring circuit elements is completely eliminated, the error caused by the flow through the winding decreases by more than 10 times electric machine direct current. In addition, when making a measurement, the useful signal greatly exceeds the level of interference. A device that implements the method is simplified, its weight and dimensions are reduced, since there is no need for circuit breakers in the separation capacitors, and because of the decrease in measuring direct current, the dimensions of the limiting inductance decrease. The determination of the winding resistance with respect to the currents in the main and auxiliary circuits provides a wide range of use for relationship meters and other means of automatic measurement, especially contactless measuring transducers, for example, direct current transformers of magnetic amplifiers and magnetic modulation sensors. The proposed method of determining the temperature provides a measurement of the resistance of the windings in a wide range of currents (up to 5 kA) and voltages (up to 1 1 kV) regardless of the connection circuit of the windings, i.e. It has a multi-functional capability that provides high unification, allowing the development of a universal measuring complex for measuring the temperature of the windings. Chesky entire range of electric cars. The method also provides a measurement of resistance in the presence of two:, g or more parallel windings connected in delta (induction pumps for pumping liquid metals). In addition, the method provides a measurement of the resistance of the windings of low frequency AC electric machines (1-10 Hz) and stepper motors.

Claims (1)

A METHOD FOR DETERMINING THE TEMPERATURE OF A WINDING OF AN ELECTRIC MACHINE UNDER LOAD, which consists in using the winding as a resistance thermometer, applying a constant current to the operating current of the winding and measuring it, characterized in that, in order to increase accuracy, a reference resistor of the auxiliary circuit is connected in series, by which pass a direct current, measure the difference in the voltage drop of the DC voltage on the winding and the reference resistor, and when the value of the difference in voltage drop is zero, measure Inu current in the winding circuit, and a resistor in a circuit model, the resistance are obmotkipo formula R Jo '' ОВм - —z ---- JoBim where J _D is the direct current in the auxiliary circuit; - resistance of a reference resistor; ? ov _m - the value of direct current in the winding circuit of the machine, which determine the desired_ temperature.