JPS5812586A - Defect detecting method for brushless circuit of synchronous motor - Google Patents

Abstract

PURPOSE:To discriminate whether a DC component current flows through a field coil or not by analyzing the frequency of an armature current at the time of starting a synchronous motor. CONSTITUTION:When a synchronous motor A is started, the armature current at the normal time becomes synthesized waveform modulated in amplitude with the power source frequency f Hz component I11 of the armature current with (1-2s)f Hz component I12, where (s) represents a slip. When an exciting thyristor 7 is conducted due to a certain reason, the armature current becomes synthesized waveform superposed of synthesized waveform modulated in amplitude with (1-2s)f Hz component I12 from the power frequency f Hz component I11 of the armature current with (1-s)f Hz component I21 flowing when the DC current flows through the field coil 2. Accordingly, the DC excitation can be detected by analyzing the frequency at the initial starting.

Description

[Detailed description of the invention] Abnormality detection 7j of the 2-cress circuit of the synchronous electric m-ridge in the main f11
modulus Vcya−rφ.

The plackless circuit of the synchronous electric wJ11A is 4 in the dark blue 1 diagram.
In figure 1 where 0 is used, synchronized to (1) 'fIL
Motion 4111 K) O111, Hatoko = li1 listening, (2)
rlkai@g, <s>a ascending atom (&) ni parallel uK-
Voltage t"ll induced in the field (1) when the stone is started
There is a discharge resistance to limit the length of the sword (4).9. fi
The field deception of excitation 愼儂), (6) and the current excitation bond (B) electric Yokozi heat-1 (6) is electric hot sauce! l Three-phase Hime flow bridge that converts the three-phase current @:tit flow that occurs in L5), (7
) This three-phase 1i flow bridge (6) is set to the output circuit of the three-phase 1i flow bridge (6), and the 1 lister (8) is synchronized.
lI When the machine power is overflowing and it is almost 100 seconds, give thyristor (7) K firing g1-I11c and 5'L m II
& (, 4 is the 1st output of the Washimoto Bridge (6) ``1 waterfall and the control module that performs synchronous pull-in 64
゜11g1 In the 11th period when the IIIE source was introduced,
When the sea bream 1c starts to appear in the sea bream (tortoise engine body), at that time, the −δ1″L voltage generated in the field winding layer (2) is suppressed to the voltage generated by the discharge resistor (8), and the ayu sea bream a II Wjl
A circuit using t, 1 and a discharge resistor ($) is a closed loop, and '111trlL' of 8fHg (here, a is 1, and f is 4 source frequency ridges) flows as shown by a broken line. Incidentally, under normal conditions, the thyristor (γ) is not conductive.

However, in this case, 1aJ et wh OA wealth causes the Siris flow to flow, but on the other hand, 410III is positive, which is the cow tIiL.
a discharge resistance 1g) Without t fi, the field a1m (2), as shown by one point arc, the three-phase luxury bridge (68 thyristors (7) are closed loops w6t-magnetization'#L flow It will flow as an engineering.

Here, when the iris resistor (7) is conducting, the field current is 1. When the iris resistor (7) is conducting, the field current is 1. (Fig. 2) The variable current consists of ! Flow branch engineering. A current flows in a biased form.
This DC Che. Kaiden number of a-transformation excitation fly machine 俤 (4)
DC j17I from just before the start of 11b until the synchronous operation
This occurs when N is given, and it also exists when there are four thyristors (7). Therefore, if such a KIf-style branching chain exists.

There is a risk that a large power generation torque will be generated at the moment of starting of the synchronous electric IIb machine (4)), making it impossible for the synchronous electric wJ aircraft (4) to rotate. In this case, a starting jam is detected and the synchronous electric S aircraft is protected by +3f.

- If the motor torque is larger than the Sa electric torque, the motor will somehow start at the beginning, but in addition to the 28 fHw O pulsating torque normally generated by the synchronous motor (4), a large pulsating torque of 5 fHz will be generated. However, when starting a load with a relatively large GD, such as a blower turbo compressor, there is a synchronous electric motor OGD in the shaft system.
GD" and the spring constant of the shaft. There are nine natural torsional vibration cycles (usually 10 to 20 Hz once).

Follow me! When a pulsating torque with the same frequency as the d*gi9shitaigang wave ridge is applied to the axoneme.

There is a risk of common loss in the @ system, generating large torque and causing temporary damage to the shaft.

Therefore, as mentioned above, the pulsating torque 2 of the synchronous motor (4)
128fHm Toh I JIS 8fHg K?
Between the start of the K shift and the completion of PMM light, the J of both ministries! This means that there are 211al rotational speeds at which the 1ltlL number matches. For example, in a 4-pole machine, the number of revolutions f't is 50Hm and the synchronous speed is 11000rp.

Firstly, 2
8f" 20 Hss, 9 B = 0.2, that is, the rotation speed of 80 rpm matches, and 8f W 2 to @2
0 Htx Yo49B! 0.4° or 4QOrp
They match at the rotation speed of m, thus 21 as the station tiL description.
− It will resonate at some point.

Since the pulsating torque for medium Te% stmz is larger than that for 2Sf, the influence on the axoneme is also greater.

Therefore, field winding - (2) VC DC component is generated and τ BfH
In the event of an abnormality in which pulsating torque of H occurs, the remaining rotation speed (601 rpm in the above-mentioned dog) is reached and the synchronization is 11!
Sea bream - (4) τ trip zazeru must buy.

By the way, this case where the era name 11° is pronounced is the case where the ignition number 1M is output from the control module (47Jjima et al. thyristor (7)) due to some reason such as noise. It is conceivable that the thyristor (7) may fail and become short-circuited.

The non-invention was made in consideration of the above points lc'4 and is 7c%.

By analyzing the frequency of the electric current at the time of starting the synchronous electric current, the direct current component can be calculated. The sword is flowing - or not, and based on this judgment result, an attempt is made to apply the abnormality detection power method of the branless circuit that makes the synchronized turtle #AO privately excited axis thread safe. .

The following is a non-inventive statement regarding the drawings.

When the synchronous 11t motion ridge (mu) started (1.0 to 0.9 @ Arashi on the 9th) during normal conditions,
□ is the power frequency f of the electric current, as shown in Figure 5AK)
I11 component work, 1 (Figure 5B) k (1-28) f
Hg ingredient engineering 2. (FIG. 5C) cvh has a composite waveform t similar to that obtained by modulating the image width by K.

If the thyristor (7) becomes conductive for some reason, the synchronous motor (4) O1 precurrent I. μ As shown in Fig. 4, the armature current power source JIIIt1 number f ■ Two-component work 2, (Fan 4 Fig. B) t (1-28) fig g min”zs ( tlA
A composite waveform similar to the amplitude modulated by C),
1. Electricity generated and flowing in (2) (1-s)
ram H minute I8゜t-weighted composite waveform t-4chi,
It is molded with ridges.

Furthermore, it can be seen that the above waveforms can be drawn over time using an IIE machine electronic current conversion t-osci-graph.

As can be seen by comparing the OR shape in Figures 5 and 4, it is clear that the flow of the KKfillE flow causes the formation of
t-a) tH*component Iso (A) is 〃0
As the speed increases, it changes from OHz to 5[In2 VC.

- (1-28) KHz component, which is the component when the sword is normal.Up to 950% speed, it is reduced to OH2 from 50Hz sword, and from 50% speed to 100% speed, it is OH21Zl- It changes from 50Hz fc. The fez component I. Only rI 5011z remains unchanged. Therefore, among the frequency components of Shinko-style, the chest wave frequency at the start of startup is t (1-s).
Only fez component processing check Ruri, other fHz K check 1
1 and (1-2s) rHz TFC branch che is the beginning 441
A sufficient distinction can be made by performing frequency analysis at the early stage of I.

For loads such as blocks and turbo compressors where fI9 vibration of the axle thread is sometimes a problem, since the GD of the axle thread is large, the startup time is relatively long, and therefore (1-8) fH two-component machining is easier to detect. This identification depends on what is done before reaching the resonance speed.

In addition, in the above-mentioned actual 4911, we investigated the problem that would occur if the thyristor (7) is connected to the temple, and the trap is that the 111N10,000 type is different 9 For example, if the thyristor is installed in a three-phase rectifier bridge without using the thyristor (7) and control module (8). When starting, it is used to block the induced current from flowing through the DI!! Since a similar phenomenon occurs in ρ, in this case, 4 !A light can be used. t *, In the static excitation method, the same is true when starting with direct VL excitation M gag flow ta dark blue.

As described above, according to the present invention, abnormality k[
* By outputting Nfikm for (1-s) fHgg of the child current, it was found that 5, 8fHg o is the brother of pulsating torque t @ thread O until the rotational speed is reached. ,'*@愼【can be tripped, so the shaft system O
By ensuring safety, we can obtain a high quality synchronous electric excitation drive system.

[Brief explanation of the drawing]

Figure 1 is an integrated diagram showing the μ synchronization'# & excitation brushless circuit, Figure 2 is rxtl! Figure 1d shows the instantaneous waveform of the electric current flowing through the field A winding magnet at the time of Im, and Figure M6 shows the electronic accent of the synchronous electric exciter in the royal palace of the Pussy 1 Fuss circuit. Figure 4 shows the different times of the brushless circuit.
Boshi Arashi-ryu T2 Bacho number technique diagram. (1) Two synchronizations' and agitating (Magano Den Shinko Street Deception (2): Kai a@
Su (8): Radiation turtle resistance (4): Variable current excitation 4 ort - 龜联网(6): Father m excitation 翿愼tB) electric shingle winding edge (6): Three-phase current bridge (7 ): Thyristor (8): Control module agent S Nosu - 1J Fig. 2

Claims (1)

[Claims] In the magnetic type synchronous electric current IIjJ, the electric current of the above-mentioned synchronous electric current can be detected by capturing a relatively low frequency component. At times, DC current may flow through the edge of the field, so please be careful when using a synchronous motor with a 1f'' value.
Constant detection power.