JPS6316300Y2 - - Google Patents

Description

[Detailed explanation of the idea]

The present invention relates to an improvement in a rotating electrical machine in which windings having two or more pole numbers are mounted on the same core. Conventionally, for example, when windings with 4 poles and 6 poles are applied to an armature core with 18 grooves, one pole and one phase of the 4 pole winding is 18/(3×4)=1.5, This is what is called fractional groove winding. In this case, two types of power supply voltages are often used; for example, when 200V/400V are shared, 2×
Double the number of parallel circuits of the winding and 1, such as Y/1×Y.
It is common to have a configuration that allows the connection to be changed twice. Therefore, if the induced voltage in the non-excited pole winding differs between circuits or between phases, a circulating current may flow between the same phases due to the potential difference, or between the phase windings. As a result, heat generation and loss increase. In addition to the above, the number of parallel circuits may be increased to increase the degree of design freedom, but similar problems can occur depending on the number of turns of the winding and the connection method, so especially when it comes to excitation poles and In the case of fractional groove winding in a rotating machine with excitation pole windings, the number of parallel circuits was usually selected to be one. The purpose of the present invention is to eliminate these drawbacks, to provide a three-phase pole number conversion rotating electric machine that allows selection of two or more parallel circuits even in a four-pole winding, and eliminates heat generation due to circulating current. . An embodiment of the present invention will be described below with reference to FIGS. 1 to 3. Figure 1 shows the case where 4-pole and 6-pole windings are applied to an armature core with 18 grooves. It is a connection development diagram of a 4-pole winding. In the figure, 1, 2, 3...18 represent slot numbers, and the solid lines indicate u1, u1', u2, u3, u.
3', u4 are the windings of the U-phase winding, v shown by the dashed line
1, v1', v2, v3, v3', v4 are the windings of the V-phase winding, w1, w1', w2, w3, shown by dotted lines
w3' and w4 are W-phase windings. The method of storing and connecting each phase winding to the slot is described below.
A phase winding will be described as an example. Coil pitch is #1
to #5, winding u1 has slot number 1.
It is formed by the lower coil housed in slot number 5 and the upper coil housed in slot number 5, and these are indicated by M1-M5. Then, the winding u1' is M2-M6, and the winding u2 is M2-M6.
6-M10, u3 is formed of M10-M14, u3 is formed of M11-M15, and u4 is formed of M15-M1, respectively. Similar tests were conducted for the V and W phases, and the results are summarized in Table 1.

[Table] Next, the end of winding u1, the beginning of winding u1', and u
The end of the winding 1' and the end of the winding u2 are connected to form the first winding group of the U phase, and the end of the winding u3 and the end of the winding u2 are connected.
The beginning of winding 3', the end of winding u3', and the end of winding u4 are connected to form a U-phase second winding group. Similarly, for the V phase, the windings v3, v3', and v4 form a first winding group, and the windings v1, v1', and v2 form a second winding group. The same applies to the W phase. Then, the respective winding ends of windings u1 and u3, v3 and v1, and w1 and w3 are connected to serve as the power supply side terminals of the U phase, V phase, and W phase, and each winding beginning of windings u2, v4, and w2 and the winding The beginnings of each winding of u4, v2, and w4 are connected to form a neutral point to form a 2×Y connection of a 4-pole winding as shown in FIG. Next, the connection method in the six-pole winding will be explained with reference to the connection development diagram in FIG. Note that the symbols are the same as those for the four poles described above. That is, the U-phase winding will be described as an example in which the number of coils q per one pole of the overlapped winding method is 1, which is an integer number of windings. Coil pitch is #1 to #4
Therefore, the winding u1 is M1-M4, and the winding u2 is M
4-M7, u3 is M7-M10, u4 is M1
0-M13, u5 is M13-M16, u6 is M
16-M1 respectively. Similar tests were conducted for the V and W phases, and the results are summarized in Table 1. Next, the end of winding u1 and the end of winding u2, the beginning of winding u2 and the beginning of winding u3, the end of winding u3 and the end of winding u4,
The beginning of winding u4 and the beginning of winding u5, the end of winding u5 and the end of winding u6 are connected, respectively. Thereafter, the V phase and W phase are also connected using the same connection method. Then, the beginnings of windings u1, v1, w1 are set to U phase, V phase,
W-phase power supply connection terminal, windings u6, v6, w6
The beginnings of each winding are connected to form a neutral point, forming a 1×Y connection of a six-pole winding as shown in FIG. Here, in the connection development diagram of Fig. 3a, Fig. 3b shows the three-phase magnetomotive force waveform at the moment when the current of the U phase is +1.0, and the V and W phases are -0.5. ,
It can be seen that six poles are formed. The induced voltage of the conductor housed in each groove of the stator in the above-mentioned state, that is, the state in which the six poles are excited, will be determined. Based on the induced voltage of any conductor, the zero point (third
Electrical angle = 0 with No. 1 groove in Figures a and b as a reference
Assume that The induced voltage Ee generated in the 4-pole winding housed in the No. 1 groove is N: Number of turns kω: Winding coefficient Em: 2πfφm (maximum value) φm: Expressed as maximum magnetic flux density, but in this formula

Since [Formula] is a common symbol for each groove, it will be omitted hereafter to simplify the explanation. In Figure 1, if the right conductor of the conductor stored in the No. 1 groove is the lower conductor and the left conductor is the upper conductor, then the No. 1
The lower conductor of the groove belongs to the U-phase winding and extends from its pitch to the upper conductor of the No. 5 groove. Therefore, the induced voltage Eu generated in this winding u1
1 is expressed as below. Eu1=Ecosωt +Ecos(ωt+240°) Here, the electrical angle per groove is 3× because it is 6 pole excitation.
360/18 = 60 degrees, and since there are 4 grooves in No. 5, the distance between No. 1 grooves is 4 x 60 = 240 degrees, and the above formula can be derived. Similarly, for winding u1' (M2-M6), Eu1' = Ecos (ωt+60) +Ecos (ωt+300) For u2 (M10-M6), Eu2 = Ecos (ωt+540) -Ecos (ωt+300) =Ecos (ωt+180) -Ecos (ωt+300) Similarly, the voltages induced in the four-pole winding shown in FIG. 1 are expressed by the following equations. Eu1=Ecosωt−Ecos(ωt+240) Eu1′=Ecos(ωt+60) −Ecos(ωt+300) Ew4=Ecosωt−Ecos(ωt+120) Ev1=Ecos(ωt+180) −Ecos(ωt+60) Ev1′=Ecos(ωt+240) −Ecos(ωt+120 ) Eu2=Ecos(ωt+300) +Ecos(ωt+180) Ew1=Ecosωt−Ecos(ωt+240) Ew1′=Ecos(ωt+60) −Ecos(ωt+300) Ev2=−Ecos(ωt+120) +Ecosωt Eu3=Ecos(ωt+180) −Ecos(ωt+60 ) Eu3′=Ecos(ωt+240) −Ecos(ωt+120) Ew2=−Ecos(ωt+300) +Ecos(ωt+180) Ev3=Ecosωt−Ecos(ωt+240) Ev3′=Ecos(ωt+60) −Ecos(ωt+300) Eu4=−Ecos(ωt+120) +Ecosωt Ew3=Ecos(ωt+180) −Ecos(ωt+60) Ew3′=Ecos(ωt+240) −Ecos(ωt+120) Ev4=−Ecos(ωt+300) −Ecos(ωt+180) Therefore, if the connection is made as shown in Figure 2 , 4
The potential difference between O1 and U1 of the pole winding is Eu1+Eu1′+Eu2=Ecosωt +Ecos(ωt+60) +Ecos(ωt+180) −Ecos(ωt+240) −2Ecos(ωt+300) Similarly, the potential difference between O1 and V1 is Ev3+Ev3′+Ev4=Ecosωt+Ecos( ωt+60) +Ecos(ωt+180) −Ecos(ωt+240) −2Ecos(ωt+300) Also, between O1 and W1, Ew1+Ew1′+Ew2=Ecosωt +Ecos(ωt+60) +Ecos(ωt+180) −Ecos(ωt+240) −2Ecos(ωt+300) Immediately Neutral point O1 -U1 and O1-V1 and O1-W
1. Each potential difference has the same magnitude (amplitude) and phase. Similarly, the voltage between the neutral point O2 and each terminal in the other circuit is: The potential difference between O2 and U2 is Eu3 + Eu3' + Eu4 = Ecosωt - Ecos (ωt + 60) -2Ecos (ωt + 120) + Ecos (ωt + 180) + Ecos (ωt + 240) ) Between O2 and V2, Ev2+Ev1′+Ev1=Ecosωt −Ecos(ωt+60) −2Ecos(ωt+120) +Ecos(ωt+180) +Ecos(ωt+240) Between O2 and W2, Ew4+Ew3′+Ew3=Ecosωt −Ecos(ωt+60) −2Ecos(ωt+ 120）＋Ecos (ωt+180) +Ecos (ωt+240) That is, neutral point O2-U2, O2-V2, O2-W
2. The potential differences of each of them are the same in size (amplitude) and phase. Therefore, unless the two neutral points O1 and O2 are connected, a so-called circulating current will not flow and no extra heat generation or loss will occur. However, since the phase is different from the voltage generated in the above-mentioned circuit, when the two circuits are connected in parallel, the neutral points must be left open. Here, the advantages of adopting fractional groove winding are roughly the following three. (a) Since the phases of each pole winding belonging to the same winding are not the same but slightly different, by connecting them in series, harmonics can be achieved without changing the winding coefficient for the fundamental wave much. Since the winding coefficient for waves can be made considerably small, a voltage close to a sine wave can be obtained with a relatively small number of slots, which has many advantages in terms of construction. (b) When using a conventional iron plate type, that is, when the same number of slots is to be shared with different numbers of poles, the number of slots for each pole is equal to one of the number of poles. There are cases where a number is not an integer. Therefore, it is economically advantageous to use fractional groove windings in this case. (c) In order to increase the space ratio of the grooves by reducing the number of grooves especially for high voltage machines, it is necessary to keep the number of slots per pole and phase to one or less.
In this case, a fractional groove winding can be used to make this possible and at the same time provide a good voltage waveform. Generally, fractional groove windings become a problem when the winding is multi-pole and multi-phase. In this case, slots in which no windings are inserted, so-called idle slots, may be used, but this is not good in terms of material utilization, so we will only deal with the case where windings are inserted into all slots. shall be. First, what conditions are necessary for the voltages (fundamental waves) of each phase to be balanced? If m = number of phases, N = total number of slots, p = number of pole pairs, and t = greatest common divisor of p and N. The electrical phase difference α between adjacent coils is α=360°×p/N…(3) However, since t is the greatest common divisor of p and N, p=p ₀ t, N=N ₀ t Then, there is no divisor between p ₀ and N ₀ . Therefore, equation (3) becomes as follows: α=360°×p ₀ /N ₀ ∴N ₀ α=360°×p ₀ …(4) Therefore, the electrical relationship of the slots is the same for every N ₀ slots. Repeating this, the 2p ₀ pole corresponds to the 2 poles of a normal integer groove winding. Consider N ₀ slots with 2p ₀ poles leaning against each other. In order to insert a symmetrical m-phase winding into such a slot, the following relationship needs to hold between N ₀ and the total number m. N ₀ /m = integer...(5) Since this is a symmetrical winding, for any slot related to the first phase, there is a slot in the second phase that is in electrical phase (2π/m) with respect to this, and (4π/m)
There is a slot in the third phase with a phase of (γ-1)2π/m, and it is generally required that a slot with a phase of (γ-1)2π/m exists in a slot related to the γ-phase. From this (5)
Naturally, the relationship in the equation must hold true. Although the equilibrium conditions for the polyphase winding have been given above, in actual cases it is convenient to give the judgment conditions from the number of slots q for each pole and each phase. For fractional groove windings, q can generally be expressed as: q=a+c/b...(6) where a, b, c=positive integers, c/b is an irreducible fraction In that case, the number of slots for two poles n ₀ is n ₀ = 2mq = 2ma + (2mc/b ) However, since c/b is an irreducible fraction, if there is a divisor between 2mc and b, it is a divisor between 2m and b. That is, if the greatest common divisor is r, then 2m=rm ₀ b=rb ₀ …(7) ∴n ₀ =2ma+m ₀ c/b ₀ …(8) Therefore, b is an integer number for ₀ pole pairs. This will include slots. The above p ₀ should be equal to this b ₀ . Therefore, since the total number of poles is 2p, the following conditions are required. p/b ₀ = integer...(9) Since the number of slots n ₀ b ₀ of this b ₀ pole number is equal to the above N ₀ , from equation (8), N ₀ = 2mab ₀ + m ₀ c However, this Equilibrium m for N0 slots
In order for phase winding to be possible, equation (5) must hold, so N ₀ /m=2ab ₀ +m ₀ c/m=2ab ₀ +2c/r = integer...(10) needs to hold. However, since r is a divisor of b and there is no divisor between c and b, there is no divisor between r and c. Therefore, in order for 2c/r in equation (10) to be an integer, the value of r can only be in the following two cases. (i) r=1 (ii) r=2 (11) That is, from equation (7), if there is a divisor of 3 or more between 2m and b, balanced m-phase winding can be implemented. do not have. Now, if we take a closer look at the cases in which equation (11) holds, we find the following: (i) When r=1 In this case, there is no divisor other than 1 between b and 2m, so b is an odd number. . Therefore, from equation (10), N ₀ /m = 2ab ₀ + 2c = even number. Therefore, from equation (5), a balanced m-phase winding can be implemented. (ii) When r=2 In this case, b=2b ₀ . Therefore, b is an even number and c is an odd number (because there is no divisor between b and c), so the following fact holds true. N ₀ /m=2ab ₀ +2c/γ=2ab ₀ +c = even+odd=odd Therefore, a two-layer winding is possible. Summarizing the above, we get the following. Now assume that the number of slots for each pole and each phase is q=c/b. If there is no divisor between 2m and b, or 2m
Balanced m-phase winding can be implemented whenever the greatest common divisor between and b is 2. Next, expressing the above-mentioned induced voltage relationship in a general formula, the induced voltage generated in the conductor of any one phase (U phase) winding of the non-excited pole is Eu1=Ecosωt...(12) All conductors are of the same pitch. Therefore, the upper conductor is separated from the lower conductor by (pitch x - groove electrical angle), and since this applies to all conductors, only the lower conductor is shown for ease of explanation. Then, the voltage induced in the conductor of the V-phase winding (located 2/3π electrical angle away from the U-phase winding) at a pole electrically k1 poles away from the u1 conductor (k1π in electrical angle) is as follows: It is expressed as Ev (k1) = Ecos {ωt + (k1π + 2/3π)} × Pf / Pe ... (13) [Here, Pe is the non-excited pole and Pf is the excited pole] Here, multiplying Pf / Pe is (k1π + 2 /3π) is expressed in terms of poles and electrical angles in the non-excited winding, so it is used to convert to the magnetic field in the excitation winding (6 poles in the example). Similarly, the conductor of the W-phase winding, which is separated by k2 poles, is separated by k2π poles and 4/3π in electrical angle from the U phase, so equation (14) is obtained. EW (k2) = Ecos {ωt + (k2π + 4/3π)} × Pf / Pe … (14) [Here, k1 and k2 are positive integers] In other words, each phase in equations (12) to (14) induced voltage of
The condition that Eu1, Ev (k1), and Ew (K2) have the same magnitude (amplitude) and phase can be found from equation (13): (k1π+2/3π)×Pf/Pe=2nπ...(15) That is, the left side ( ) This holds if the inside is an electrical angle of zero or a multiple of 360°, and as a result, Ev (k1) = Ecos (ωt + 2nπ) = Ecosωt, which is the same value and phase as Eu1 in equation (12). . Similarly, when formula (14) is calculated for the W phase, it becomes (k2π+4/3π)Pf/Pe=2n′π (16). k1 and (16) obtained from equation (15) above
k2 obtained from the formula is the magnitude of the induced voltage in each phase conductor,
The phase joint condition is one condition. As an example, when calculating k1 and k2, Pe = 4 (pole) Pf = 6 (pole) From formula (15) (k1 + 2/3) = 6/4 = 2n k1 = 2n × 4/6 - 2/3 = 2 (n=2) From equation (16), (k2 + 4/3) 6/4 = 2n' k2 = 2n' x 4/6 - 4/3 = 0 (n' = 1) However, K2 = 0 means W This means that the phase winding is 0 poles apart in electrical angle from the U phase, which cannot be true, so by further changing n', we can find K2 where the U phase pole and the W phase pole are true. If you ask, n′=
4, we obtain the integer 4, K2=2n'×4/6-4/3=4. Pe=8 (pole) Pf=6 (pole) From equation (15) (k1+2/3)6/8=2n k1=2n×8/6-2/3=2(n=1) From equation (16) (k2+4/3)6/8=2n'(k2=2n'×8/6-4/3=4(n'=2) Pe=4 (pole) Pf=12 (pole) (K1+2/3)12 /4=2n K1=2n×4/12-2/3=2(n=2) (K2+4/3)12/4=2n'K2=2n'×4/12-4/3=4(n' = 4) Pe = 8 (pole) Pf = 12 (pole) (K1 + 2/3) 12/8 = 2n K1 = 2n x 8/12 - 2/3 = 2 (n = 2) (K2 + 4/3) 12/ 8=2n'K2=2n'×8/12-4/3=4(n'=4) Table 2 summarizes k1 and k2 at the pole number ratio in this relationship, and K1=2, K2=4.

[Table] In other words, if one circuit of a parallel circuit is formed using the conductors of each phase obtained from equations (15) and (16), the potential differences between the neutral point and each phase terminal are all the same size, and the phase is the same. Therefore, all three phases are balanced and the potential difference between the terminals is zero. In the example, the U phase is made up of U1 winding, U1' winding, and U1 winding, the V phase is made up of V3 winding, V3' winding, and V4 winding, and the W phase is made up of W1 winding, W1' winding, and W2 winding, forming one circuit. (Fig. 2, 4-pole U1,
V1, W1 output circuit) is formed. Similarly, the other circuit is formed as follows. The U phase is U2 winding, U2' winding, and U4 winding. The V phase is V1 winding, V1' winding, and V2 winding. The W phase is W2 winding, W2' winding, and W4 winding. Both circuits have a neutral point. The potential difference between the terminals is the same, and the potential between the terminals is zero. That is, the two circuits formed in this way are connected to each other (U1 and U in Fig. 2).
2, V1 and V2, and W1 and W2), no potential difference is generated in both circuits, so no circulating current flows and no excessive heat generation or increase in loss occurs. Also, to find the conditions for Pf, we can use formula (15) as a representative: (k1π+2/3π)Pf/Pe=2nπ If we divide both sides by π, we get the formula (k1π+2/3π)Pf/Pe=2n, Here, k1 is a positive integer and n is also an integer, so in order for this equation to hold, Pf must be a multiple pole of 3, that is, a multiple pole of 6. The developed winding diagrams when Pe/Pf=8/6 are shown in FIGS. 4a and 4c, and the connection circuit diagrams are shown in FIGS. 4b and d. Table 3 shows the relationship between the windings and the slot arrangement. When Pe/Pf=8/6, the number of slots becomes 36.
This is double the 18 pieces when Pe/Pf=4/6,
The number of coils per -pole in 6 poles is Pe/Pf=
Although the number of wires is changed from one in the case of 4/6 to two, the winding configuration and operation and effect are the same. Next, when Pe/Pf=4/12 and Pe/Pf=8/12
The winding development diagrams in the case of are shown in Fig. 5 a, c and Fig. 6 a, c, respectively, and the connection circuit diagrams are shown in Fig. 5 b, d and Fig. 6.
They are shown in Figures b and d, respectively. Tables 4 and 5 show the relationship between the windings and the slot arrangement. In this case as well, the winding configuration and effect are the same as in the case where Pe/Pf=4/6.

【table】

【table】

【table】

【table】 [Brief explanation of the drawing]

Fig. 1 is a winding development diagram of a four-pole winding showing an example of the present invention, Fig. 2 is a connection circuit diagram, Fig. 3 is a winding development diagram and magnetomotive force waveform diagram of a six-pole winding, and Fig. 3 is a winding development diagram of a six-pole winding. Figure 4 is Pe/
When Pf is 8/6, Figure 4 a and c show the developed winding diagrams of 6-pole and 8-pole windings, and Figure 4 b and d are connection circuit diagrams, respectively.
Figure 5 is when Pe/Pf is 4/12, and Figure 5 a and c are
The winding diagrams of 12 poles and 4 poles are shown, b and d are the connection circuit diagrams respectively, Figure 6 is when Pe/Pf is 8/12, and Figure 6 a and c are the winding diagrams of 12 poles and 8 poles. The winding development diagram is shown, and b and d in the figure are connection circuit diagrams, respectively. Pf...Number of excitation poles, Pe...Number of idle winding poles, n,
n'...Integer, 1, 2, 3...18...Slot number.

Claims (1)

[Scope of utility model registration request] In the armature winding with the number of poles Pf which is an integral multiple of 6, and the armature winding with the number of poles Pe with fractional groove winding connected by adjacent poles installed on the same armature core, any U-phase winding And from this arbitrary winding (2+2/
3) A V-phase winding separated by an electrical angle of 2π that satisfies Pf/Pe=2n (where n is a positive integer) and (4+4/3) Pf/Pe=2n' (where n' is a positive integer) W-phase windings separated by an electrical angle of 4π are connected at one neutral point to form two or more parallel circuits.