JPS592600A - Controller for flywheel - Google Patents

Abstract

PURPOSE:To perform the control of constant electric power without extreme field weakening control by employing an armature coil switching control together with an armature current control or field control. CONSTITUTION:Contacts 2u, 2v, 2w are closed at the starting time, armature coils Wu and Wx, Wv and Wy, Ww and Wz of the respective phases are connected in series with each other, the armature current ia is maintained constantly, and a flywheel is accelerated with a constant torque. After the rotating speed becomes N1, it is accelerated in the constant power control mode. When the rotating speed becomes N3, contacts 1u and 3u, 1v and 3v, 1w and 3w are closed and 2u, 2v, 2w are opened upon reception of the output signal of a pulse generator PG. Accordingly, the armature coils are connected in parallel with each other. As a result, each of the currents becomes twice that before switching, the constant power state is maintained, and the flywheel is accelerated to the maximum rotating speed N2.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an efficient flywheel control device that uses a synchronous motor as a drive motor-generator in a flywheel device intended for storage of force.

[Technical background of the invention]

The use of flywheels is being considered as a power storage device that stores surplus power during the night and returns power to the grid during heavy loads during the day. The concept of temporarily storing electrical energy as rotational energy and converting it back into energy when needed is characterized by its very simple principle, non-polluting nature, and suitability for distributed deployment. However, since a large amount of power is transferred from the power grid, it is required to minimize the fluctuation of reactive power accompanying energy charging and discharging or the generation of 1.1: disturbance harmonics. If the ineffective frost, force, and harmonics are small, the overall size of the device is also small, and the loss of the device is also reduced, which contributes to system efficiency and cost reduction.

FIG. 1 shows an example of the interior of a conventionally proposed flywheel drive device. A transformer R: ÷ Tr is connected to the single chicken system S, and a converter C0NV is connected to the secondary winding.
l is connected and threaded. The output circuit of the converter C0NV1 is connected to the inverter INV through the axle Lgk,
Synchronization: Motive SM is connected and drives the flywheel F/W. Ps//i is a rotor position detector and provides a dirt signal to the inverter INV via the control device c2. The control system of FIG. 1 has two 1h control loops: a field control loop and a power control loop. The rotational speed of the flywheel F/W is detected by a pulse generator PG. The field current/turn generator receives the signal from the pulse generator PG and gives a field current command to the converter C0NV, so that the current of the field F is controlled. The power command is usually given a constant value, and the converter C0 is compared with the detected power.
Controls the control delay angle of NV l. Therefore, charging or discharging is controlled with constant power between the lower limit value and the upper limit value of the rotation speed.

FIG. 2 shows voltage and current characteristics for explaining the system of the conventional embodiment. At the time of starting, the field current if is kept constant. The speed electromotive force ec increases in proportion to the rotation speed. Keep the armature current constant. When the number of rotations reaches N1, the field current if is made smaller in inverse proportion to the number of rotations. N2
is the maximum rotational speed, and between N1 and N20, the speed electromotive force ec is constant and the armature current iF is constant, that is, the electric current is constant and acceleration is performed.

The same is true when returning to the energy 't1M flow, and the rotation speed is N.
From 2 to Nl, the field current 11 is increased in inverse proportion to the number of rotations, and the electric power is regenerated in a constant state. The rotational speed range between N and -N is usually used. The flywheel drive device shown in Fig. 1 controls the input power Mi of the system by field control, and the voltage of the DC circuit,
F, J, l'1. is controlled to be constant, the control lag angle of converter C0NV is also t'! is constant. Therefore, fluctuations in reactive power due to power transfer are small, and ideally it is possible to operate at a power factor close to 100%. It also has the advantage of having small harmonic voltages and low harmonic currents, which have little negative impact on the grid.

[Problems with background technology]

However, in the self-controlled non-commutator type 5 motor consisting of an inverter INV, a synchronous motor SM, and a position detector ps, the commutation advance angle decreases greatly due to field weakening control. When controlling over a wide range, there is a drawback that it is necessary to sacrifice the dimensions of the synchronous motor SM and the impeller INV to adopt larger ones.

[Purpose of the invention]

The purpose of the present invention is to solve the above-mentioned drawbacks. By using plate winding switching control and 1L current control or field control in combination, constant power control is performed without extreme field weakening control. Flywheel control & tz:

[Summary of the invention]

To achieve this objective f: the present invention provides a synchronous motor with
The armature winding is divided as appropriate and switched in series or parallel depending on the speed of the synchronous motor, and the armature current control or field current control is used in combination to control the electric power. It is characterized by the fact that

[Embodiments of the invention]

FIG. 3 is a configuration diagram showing an embodiment of the present invention. In the figure, S represents a power system, Tr represents a transformer, CONV represents a converter, INV represents an inverter, and L8 represents a DC reactor. Synchronous power supply connected to two inverters! The identifier winding of the JXII machine is W for each phase. and Wx v Wv and Wy9w
It is divided into two parts (turn ratio l:1) like w and W2,
Series and ascending connections can be made by operating switches cu, cv, and cw. In addition, switch C
u, Cv.

The Cw switching command is issued by signals from a rotor and flywheel rotational speed detector PG (not shown). The field of the synchronous motor SM can be controlled to be weakened if necessary, but this is omitted in the configuration diagram of FIG. Ps is a rotor position detector, and C2 is a 1tjlJ control circuit that provides a dirt signal to the inverter. Furthermore, the comparator C3 calculates the deviation between the frost force command and the detected %1 force, and the converter C0NVi is opened to the output of the shifter C1.

FIG. 4 shows one method of operating the embodiment of FIG. 3, in which the field current if is held constant and armature switching control and armature 'F@ and C control are used together. At startup, contacts 2u, 2v, 2 are connected to switches Cu, Cv, and Cw.
w is turned on, the raw plate windings are connected in series, and the armature current ia is kept constant to accelerate with constant torque. After the rotational speed reaches N, it is accelerated in constant power control @l mode. Therefore, the armature current ia decreases approximately in inverse proportion to the rotation speed. When the rotation speed reaches 1818 g, a switching command is given to the switch Cu+ Cy rCw in response to the output signal of the pulse generator PG, and the contacts 1u and 3u + 1v and 3v, 1w and 3w
turns on and 2u + 2V + 2w turns off, so the armature windings are connected in parallel. This result induces 11]1
The pressure becomes 1/2 the magnitude before switching, the current and current become twice the magnitude before switching, and the constant power state is maintained and the flywheel is accelerated to the maximum rotational speed N2. . If you follow the control method shown in Figure 4, field weakening control will not be performed, so the electric power
The J machine's electric current is less affected by the effects of qI, and the decrease in the inverter's commutation angle is relatively small.

Therefore, since the overload resistance μ is large, the size of the inverter and electric motor can be small. Armature current i8 with constant power control
and armature box, the pressure fluctuates, but the range of fluctuation is small because armature winding switching is also used. Naturally, the variation in the control delay angle of the converter C0NV, which directly affects the system, is also small, so constant power control is performed without significantly deteriorating the power factor. When the energy stored in the flywheel is returned to the power grid, INV operates as a converter and C0Nv operates as an inverter, but the armature winding rotates at a preset rotation speed of 1. &
The ability to switch from parallel to column 11 in Ns (afterwards) is consistent with acceleration mode, and regenerative operation by constant force is OJ function.

FIG. 5 shows another method of operation that can be controlled in the embodiment of FIG. In other words, it is a combination of child winding switching control and field weakening ll+ control, and the induced voltage and 'lij
The state of machine intelligence is constantly controlled n11. During the starting rotational speed of 0 to N·'+, the armature winding is connected in series, the field current is constant, the armature current is also constant, and acceleration is performed at a constant torque. The rotational speed is set to N, and thereafter the motor enters the power mode at constant fh, and field weakening control is performed.

When the rotation speed reaches N3, the raw plate winding is switched to the switch Cut.
It can be switched from series to parallel by operating Cy + CWk. At this time, in order to maintain the induced kEok constant,
Field current 'f6: strong whistle voltage, armature current constant (
In other words, it accelerates in a state of constant power). Since energy is not recovered from dust at the highest rotational speed, if one short axis is used for one fixed control side, the opposite of acceleration can be considered. That is, as the rotational speed decreases, the field current if is increased and strengthened, and when the speed reaches N3, the armature windings are switched from parallel to series.

At this time, the field current is reduced to 1/2 in order to maintain the induced voltage constant, and is gradually strengthened as the rotation speed further decreases. According to the operating system shown in Figure 5, the armature voltage, armature fingers, and flow are both accelerated or decelerated while remaining constant, so fluctuations in reactive power due to energy transfer are small, and the power factor is almost constant. Since it is used in a state close to 100%,
The negative impact on the power system will be very small.

Fig. 6 shows another implementation ++1, which differs from the embodiment shown in Fig. 3 in that the armature winding 1 is connected in series or parallel 'ItC on the input side of the inverter instead of being switched in parallel. This is to obtain the effect of The armature winding Wl and the output of the inverter ItJV, , are connected, while the armature winding W2 and the output of the inverter INV* are connected. The DC inputs of inverters INV and INV2 are contacts 1d,
One DC reactor is connected to the negative terminal of the converter through a switch Cdi having terminals 2d and 3d. Depending on the rotational speed, the switch c'd is shifted across the entire range, and when the rotational speed is below N3, contacts 2d and 1dt3d are turned on, and inverters INVB and INV2 (i7 in series) are connected, and when N3 and above, contacts 2dt and 1dt3dffi are turned on. 1.If used in conjunction with the control of the state current ia or the field current 61, it goes without saying that the control shown in Figs. 4 and 5 is possible; Compared to the embodiment shown in the figure, the number of switches is reduced, making the rod construction easier.
Since this is a parallel connection in a DC circuit, the armature winding W.

Although the phases of and Wz are the same, there is no necessity. If the phase difference θ between the armature windings W and Wz is appropriately set, the armature magnetomotive force becomes close to a sine wave, and the harmonic loss of the motor is reduced, contributing to higher efficiency.

When performing constant power control in a flywheel drive device that receives power from a syrisk converter and incorporates an inverter, a four-cycle controller, and a motive power, the rotational speed At the same time, the armature voltage increases, so the control delay angle of the converter fluctuates significantly, causing a change in the power factor, which inevitably affects the power system.In addition, the actual voltage rating of thyristor converters and inverters This results in a large space expansion and an increase in dimensions.As shown in Figure 1, when used in conjunction with field current control, the rust electromotive voltage becomes constant and the armature current also becomes almost constant, making it ideal for constant power. Control is theoretically possible, but in reality, synchronized i!
When self-restraint control of fI1 aircraft is performed only by natural commutation, the commutation margin angle decreases significantly. I had no choice but to use a motor with a larger capacity than necessary and use it in a light load area.

〔Effect of the invention〕

Constant force control f:' is carried out on the cross-current side or direct-current side of the series/parallel switching gold inverter with 5 windings for non-inventive purposes 1 and ', and is used in combination with root current control or field current control. l
It is a J-noh, and has features similar to those of 组.

(1) The range of constant torque control is wide, and the energy efficiency of the flywheel system is high.

(2) Equipment capacity such as transformers, thyrisk converters, thyrisk imparks, synchronous frosts, shaft rears, etc.; (1 or less is enough.

(3) Chopsticks are effective, the magnitude and fluctuation of force are small, and they do not cast a spoonful shadow on the power grid.

[Brief explanation of drawings]

Figure 1 is a configuration diagram of a conventional flywheel drive device, Figure 2
The figure is a voltage and current characteristic diagram with respect to rotational speed to explain the operation of the drive device in Figure 1, Figure 3 is a configuration diagram showing an embodiment of the present invention, and Figures 4 and 5 are as shown in Figure 3. FIG. 6 is a block diagram showing another embodiment of the present invention. S...? +1, Power system, Tr...Transformer, C0NV
1...Converter, ■Nv...Inverter, L8.
...DC reactor, SM...synchronous motive, F...
Field winding, F/W... flywheel, PS... rotor position 1u detector, PG... pulse generator, C0Nv
2...Converter, C3...Comparator, C,...Phase control circuit, C2...Inverter control circuit, C4...
・World im fti control circuit, coNv...converter, Wut Wy + WW + WX + Wy
e Wz...armature winding, Cu, Cv, Cw, cd
...Switch, wl, w・2...electrodepositor winding. Applicant Substituted Haiku Poet Patent Attorney Suzue Takeshi Mutsu Chito's Wisdom History - 19 α Chioki's Set Screw - - Only 0

Claims (2)

[Claims] (1) A flywheel control system comprising a synchronous motor coupled to a flywheel, a power converter for controlling input power and regenerative power of the synchronous motor, and a rotational speed detector of the synchronous motor, The synchronization tI
The armature winding of the II1 machine is divided as appropriate, and a switch is provided to connect the armature windings in series or in a row, and switching is performed according to the magnitude of the detected speed, and armature current control or A flywheel control device characterized by performing power control in combination with field current control. (2) In a flywheel control device comprising a synchronous motor coupled to a flywheel, a power converter for controlling input power and regenerative power of the synchronous motor, and a rotational speed detector using the synchronous 1 as a motive, The armature winding of the synchronous W motor is divided as appropriate, and the power converter is provided correspondingly, and the divided armature winding is connected to each power converter and converter, and the input of the power converter is open to the side,
A closure is provided and switching is performed according to the magnitude of the detection speed.
A flywheel control device characterized in that the power converters are connected in series or parallel, and power and control are performed using armature current control or field current control 1 in combination.