JPH01311892A - System of operating rotary machine - Google Patents

Abstract

PURPOSE:To suppress the pulsation of a reactive current the side of the input of a cycloconverter by operating a rotary machine at a variable speed while a circulating current flows from the cycloconverter without providing a current limiting reactor. CONSTITUTION:A group rectifiers 13A, 14A, 15A of a cycloconverter 12 are connected to B group rectifiers 13B, 14B, 15B through the double master windings 13C, 14C, 15C of a rotary electric machine. Thus, if the phases of the output currents of the A group rectifiers from those of the B group are suitably displaced, the fact that the A group rectifiers and the B group rectifiers simultaneously generate a '0' current zone can be eliminated. Since a circulating current can flow between the A group rectifiers and the B group rectifiers, the quantity of the circulating current is suitably controlled to suppress the pulsation of a reactive current at the side of the input of the cycloconverter 12 can be suppressed to a small value.

Description

[Detailed Description of the Invention] [Objective of the Invention] (Industrial Application Field) The present invention provides a cycloconverter (hereinafter referred to as C, C) without providing a circulating current suppressing reactor (hereinafter referred to as current limiting reactor). This invention relates to a rotating machine operating system that variably operates a rotating machine while flowing a circulating current.

(Conventional technology) As a rotating machine operating system that operates a rotating machine at variable speed,
Circulating current type C, C, and non-circulating current type C, C.

It has been known. (For example, Electric Power Technology Research Group Material No. PE-87-141).

FIG. 8 is an example of the connection of the circulating current types C, C, and shows the connection of the converter per -phase.

Positive group rectifier circuit (P) (hereinafter referred to as positive group) and negative group rectifier y
Pt(N) (hereinafter referred to as negative group) is constantly operating,
In order to reduce the circulation of ripple current due to the difference in instantaneous voltage between the positive group (P) and the negative group (N), a current limiting reactor (2) is provided. In addition, in order to prevent the positive group (P) and negative group (N) from being short-circuited via C, C, and the power transformer (A),
A positive group (P) transformer winding (4a) and a negative group (N) transformer winding (4b) are provided separately.

Figure 9 is an example of the connection of non-circulating current types C and C.

- Shows the converter connections per phase.

Only one of the positive group (P) and negative group (N) rectifiers is operated alternately depending on the current of the load (2).

Therefore, since no circulating current flows, there is no need to provide a current limiting reactor, and there is no need to separate the transformer windings (A) for the positive group (P) and the negative group (N).

The reactive power (hereinafter referred to as VAR) on the input side of C, C, is:
It pulsates at a frequency six times the output frequency of C, C, but if the pulsation of this VAR is large, it also causes the VAR of the power supply system to pulsate, which has an adverse effect on the power supply system.

Circulating current type C, C, has no zero current section and can control the circulating current to reduce VAR pulsation, so compared to non-circulating current type C, C, it has less effect on the power supply system. This has the advantage of having a small impact.

However, the circulating current type C,C requires a current-limiting reactor (2), and also the circulating current type C,C for the positive group (P) and the negative group (N).

It was necessary to separate the windings of the power transformer, which had the disadvantage of increasing the size of the device.

On the other hand, in the non-circulating type C, C, there is no need to provide a current limiting reactor, and it is necessary to separate the windings of the power transformer (A) for the positive group and the negative group. This has the advantage that the device is small and the circuit configuration is simple.

However, the acyclic form C,C, has a positive group (P) and a negative group (N)
When switching, a current O section occurs.

In addition, since a circulating current cannot flow, the VAR on the input side of C, C, pulsates depending on the output current of C, C, which in turn causes the VAR of power system 0 to pulsate. Ta.

(Problems to be Solved by the Invention) As described above, the conventional circulating current type C, C has the disadvantage that the device becomes large, and the conventional non-circulating current type C, C
, had the disadvantage that the VAR consumed pulsated and had an adverse effect on the power supply system, and was extremely unsatisfactory.

In the present invention, the equipment configuration of C, C, is a non-circulating current type C, C,
is the same as , but eliminates the current 0 section, allows circulating current to flow, controls the amount of circulating current, and VAR on the input side of C, C,
An object of the present invention is to provide a rotating machine operating system that can control pulsation to a small level.

[Structure of the invention]

(Means for Solving the Problem) In order to achieve the above-mentioned object, the present invention provides a rotating machine (
11) and C, C, (12) and C, C, power transformer (1
6), C, C, U phase A group rectifier circuit (13A)
and U phase B group rectifier circuit (13B), V phase A group rectifier circuit (13B),
4A) and V-phase B group rectifier circuit (14B), and W-phase A group rectifier circuit (15A) and W-phase Bl rectifier circuit (15B)
teeth.

U-phase winding (13G) and V-phase winding (14G) of the rotor, respectively.
G) and W phase winding (isc).

(Function) With this configuration, the A group rectifier circuit and the B group rectifier circuit are connected through the windings of the rotating machine, so the phases of the output currents of the A group rectifier circuit and the B group rectifier circuit can be adjusted appropriately. By shifting the current to 0, it is possible to prevent the A group rectifier circuit and the B group rectifier circuit from simultaneously generating the current O section. Also, circulating current can flow between the A group rectifier circuit and the BW rectifier circuit.

Appropriately control the amount of circulating current and set the VAR on the input side of C6C0.
Pulsation can be suppressed to a small level.

(Example) Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 2 is a wiring diagram of an operation system for variable speed operation of a wound induction machine by secondary excitation control.
) is connected to the power supply system (0) via the main transformer (31).The secondary winding (21) of the induction machine (20)
2) is double star connected, and the secondary winding (22) includes U finger whistle 1 winding (23A), U finger whistle 2 winding (23B), V finger whistle 1 winding (24A), and V finger whistle 2. Winding wire (24B), W finger whistle 1
The winding (25A) and the W finger whistle 2 winding (25B) are connected to the U phase A group rectifier circuit (13A) of C, C, (12), U
Phase B group rectifier circuit (13B), V phase A group rectifier circuit (14
A), V phase B group rectifier circuit (14B), W phase AW! ! It is connected to the current circuit (15A) and the W-phase B group rectifier circuit (Is B ), and is subjected to secondary excitation control.

The magnetic flux generated in the U-phase secondary winding (23) of the induction machine (20) is generated by the U-finger 1 winding (23A) and the U-finger 2 winding (23B).
) is determined by the current flowing through the Therefore, by controlling the output currents of the U-phase An rectifier circuit (13A) and the U-phase B group rectifier circuit (13B), a desired magnetic flux of the U-phase secondary winding can be obtained. Similarly, V phase A group rectifier circuit (14
A ) and V-phase B group rectifier circuit (14B), and W
Phase A group rectifier circuit (15A) and W phase B group rectifier circuit (
15B), the desired magnetic flux of the V-phase secondary winding (24) and the W-phase secondary winding (25) are controlled.
magnetic flux can be obtained. In this way, the secondary winding (22
), the induction machine (20) can be operated at variable speed.

■The current in the sum circuit leads the current in the U sum circuit (13) by 120° in phase, and the current in the W sum circuit has a waveform in which the phase leads the current in the U sum circuit (13) by 240°, so the waveform is as follows. ,
The flow of current will be explained by taking the current of the U sum circuit (13) as an example. Figure 3 is a diagram showing the flow of current in the U phase. The U phase A group output current (Iua) of the rectifier circuit (13A) is:
From the U-phase An11 flow circuit to the neutral point of the induction machine secondary winding (40
), the group load current (I uaQ) to the U phase flowing to the sum circuit (14) and the W sum circuit (15) and the U phase ring current (I uc) flowing to the U phase B group rectifier circuit (13B). It becomes peace.

Similarly, the U phase B group output current (I ub) of the U phase B group rectifier circuit (13B) is the U phase B group load current (I ulJ)
and the U-phase ring current (I uc).

As shown in Figure 4, the U-phase A group load current (I uaQ) and the U-phase B group load current (I ubQ) are controlled to produce a certain phase difference.For convenience, this phase difference is set to 30@. do. U
In the SA group negative back load current flow 0 section (41a), the U phase B group load current (I ubl) does not become the O section, and conversely, the U
In the current 0 section (41b) of the phase B group load current, the U phase A group load current (Iual) does not become the O section.

Therefore, no current O section occurs in the U sum circuit (13).

Figure 5 shows the changes in VAR (Qu) on the U-phase input side, VAR (QuI2) generated according to the tJ' phase load current, and VAR (Quc) controlled by the U-phase ring current. In the figure, VAR (Qu) on the U phase input side is the sum of V A R (Qu phantom) generated by the U phase ring current and V A R (Quc) controlled by the U phase ring current. The vAR (Quc) controlled by the ring current is
By controlling the U phase ring current (I uc), it is possible to change it arbitrarily, so VAR (Quc) controlled by the U phase ring current can be changed to V A R (Quj+) generated according to the U phase ring current. ), it is possible to suppress the pulsation of VAR (Qu) on the U-phase input side.

The U sum circuit (13) has been explained above, but the sum circuit (14) and the W sum circuit (15) are also similar to the U sum circuit (13) by eliminating the zero current section and It becomes possible to suppress pulsation of VAR.

In the above embodiment, without providing a current limiting reactor,
Further, it is possible to eliminate the current O section and to flow a circulating current without separating the windings of the C, C, and power transformers into positive group (P) and negative group (N). Therefore, C,
It becomes possible to suppress the VAR pulsation on the input side of C, and it becomes possible to eliminate the adverse effect on the power supply system.

The present invention is not limited to the embodiments described above, but can also be applied to the device configurations shown in FIGS. 6 and 7.

FIG. 6 is a wiring diagram of an operation system for variable speed operation of an induction machine by primary frequency control, and the primary winding (51) of the induction machine (50) is double star connected.

U finger whistle 1 winding (53A) of primary winding (51), U finger whistle 2
winding (53B), V finger whistle 1 winding (54A), V finger whistle 2 winding (54B), W finger whistle 1 winding (55A), and W finger whistle 2
The windings (55B) are C, C, (12) U phase A group rectifier circuit (13A), U$lBi rectifier circuit (13B),
Group rectifier circuit (14A) to V phase, V phase B group rectifier circuit (14A)
B) is connected to the W-phase A group rectifier circuit (15A) and the W-phase B group rectifier circuit (15B). By changing the output frequency of C, C, (12), the primary winding (51) of the induction machine (50)
) The induction machine (50) can be operated at a variable speed by changing the rotational speed of the rotating magnetic field. In the embodiment shown in FIG. 6, C, C, (12) is added to the above embodiment.
By controlling the load current and circulating current of C, C, (12)
It is possible to eliminate the zero current section and suppress VAR pulsations on the input side.

FIG. 7 is a wiring diagram of an operation system that controls the frequency of armature current to operate a synchronous machine at variable speed.
The armature winding (61) of 0) is double star connected,
U-finger 1 winding (63A) of armature winding (61).

U finger whistle 2 winding (63B), V finger whistle 1 winding (64A), V
Finger whistle 2 windings (64B), W finger whistle 1 winding, 11 (65A
) and the W-phase second winding (65B) are C, C,
(12) U phase A group rectifier circuit (13A), U phase B group rectifier circuit (13B), V phase A group rectifier circuit (14A), V phase B
e1l flow circuit (14B).

W-phase A-group rectifier circuit (15A) and W-phase B-group rectifier circuit (
15B). C: By changing the output frequency of C, (12), the armature winding (61) of the synchronous machine (60)
By changing the rotational speed of the rotating magnetic field, the synchronous machine (60) can be operated at variable speed. In the embodiment shown in FIG. 9, C and C are used similarly to the above-mentioned embodiment.

If the load current and circulating current in (12) are controlled, C, C.

By eliminating the current 0 section in (12), it is possible to suppress VAR pulsations on the input side.

〔Effect of the invention〕

According to the present invention, the rotating machine is operated at variable speed while flowing a circulating current from the cycloconverter without providing a current limiting reactor, so that the following effects can be obtained.

(2) Since the zero current section of the cycloconverter can be eliminated and a circulating current can be caused to flow, it is possible to suppress the pulsation of the reactive power on the input side of the cycloconverter.

■ The current limiting reactor can be omitted, and the number of windings in the cycloconverter power supply transformer can be reduced, which greatly simplifies the circuit configuration and reduces equipment installation space.

[Brief explanation of the drawing]

FIG. 1 is a wiring diagram showing the configuration of a rotating machine operating system according to the present invention, and FIG. 2 is a wiring diagram of an embodiment in which the present invention is applied to a system that operates an inductor at variable speed by secondary excitation control.
Figure 3 is an explanatory diagram showing the flow of current in the U sum circuit in Figure 2;
FIG. 4 is an explanatory diagram showing the current waveform of the U sum circuit in FIG.
Fig. 5 is an explanatory diagram showing the fluctuation of the reactive power on the input side of the U-sum circuit in Fig. 3, Figs. 6 and 7 are connection diagrams showing other embodiments, and Fig. 8 is the circulating current of the conventional example. FIG. 9 is a wiring diagram showing the configuration of one phase of a conventional non-circulating current type cycloconverter. 3... Current limiting reactor 4... Transformer winding 4a...
・Positive group transformer winding 4b...Negative group transformer winding 5...Load 6...
Power supply system 11...Rotating machine 12...Cyclo converter 13...U sum circuit 13A...U$l
A group rectifier circuit 13B...U phase B group rectifier circuit 13G...U phase winding of rotating machine 14...V sum circuit 14A...VNA group rectifier circuit 14B...V phase B group rectifier circuit 14G...V phase winding M of the rotating machine 15...V sum circuit 15A...W phase A group rectifier circuit 15B...W phase B8# rectifier circuit 15G...W phase winding 16 of the rotating machine ...Cycloconverter power supply transformer 20...
Induction machine 21...Primary winding 22...Secondary winding 23...U phase secondary winding 23A...U finger whistle 1 winding 23B...U finger whistle 2 winding 24...・V phase secondary winding 24A...V whistle 1 winding 24B...V finger whistle 2 turns, iiR25...W phase secondary winding 25A...W finger whistle 1 winding 25B...・W finger whistle 2 winding 31...Main transformer 40...Neutral point of induction machine secondary winding 41a...U
Current O section 41b of phase A group load current...Current O section 50 of U phase B group load current...Induction machine 51...
・Primary winding 52...Secondary winding 53A...U
Finger whistle 1 winding 53B...U Finger whistle 2 winding 54A...V
Finger whistle 1 winding 54B...V Finger whistle 2 winding 55A...W
Finger whistle 1 winding 55B...W finger temperature 2 winding 60...Synchronous machine 61...Armature winding 62...Rotor 62A
...Field winding 63A...U group 1 winding 63B
...U finger whistle 2 winding 64A...V finger whistle 1 winding 64B
...V finger whistle 2 winding 65A...W finger whistle 1 winding 65B
...W finger temperature 2 winding I uaQ...U phase A group load current I ub12- U HB back load current Iuc...U phase circulating current Qu...Reactive power QuQ on the U phase input side...・Reactive power Qu generated according to U member charging current
c... Reactive power P controlled by U-phase circulating current...
・Positive group rectifier circuit N...Negative group rectifier circuit Figure 3 Figure 4 Figure 7 Figure 8

Claims (1)

[Claims] In a rotating machine drive system consisting of a rotating machine in which the primary or secondary windings are double-star connected, and a cycloconverter for controlling the current of these windings,
A rotating machine operating system characterized in that a circulating current of a cycloconverter is caused to flow through a neutral point of the primary or secondary winding.