JPH01270781A - Damping device - Google Patents

Abstract

PURPOSE:To suppress fluctuation of input voltage of a power converter even after a DC power source is disconnected by zero controlling input of the power converter at the time of stop of a flywheel, then turning OFF a chopper, and then connecting a damping resistor. CONSTITUTION:When a stop button 50a is pressed, a changeover relay 43 is turned ON, and a power reference value of the input of a power controller 31 becomes '0'. A changeover relay 48 becomes OFF after a set time of a delay circuit 51, and a chopper 100 is turned OFF. Simultaneously, a switch 3 is released. Further, a switching relay 44 is turned ON, and a slip frequency f is determined according to the variation of an input voltage Vd. Then, after the release of the switch 3 is confirmed, a switch 40 is closed to connect a damping resistor 41. A chopper 100 starts operating, and a frequency command is calculated in response to the output of a ramp generator 47. Thus, the energy of the flywheel 8 is consumed by a damping resistor 41.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a flywheel that stores surplus power of a contact line in a flywheel and releases the stored power when there is a power shortage to compensate for the power shortage. The present invention relates to a braking device for an energy storage device.

[Conventional technology]

FIG. 3 is a circuit diagram showing the configuration of a braking device of a conventional flywheel energy storage device described in, for example, Japanese Patent Application No. 1, 1981-281736, and in the figure, 1 is a DC feeding circuit ( 2 is a grounding wire, 3 is a switch, 4 is a DC reactor, 5 is a capacitor, 6 is the main circuit of a power converter (hereinafter simply referred to as a power converter), 7
is a three-phase induction machine, and 8 is a flywheel connected to this three-phase induction machine.

The power converter 6 is a semiconductor switching element, in this example, a gate turn-off thyristor (hereinafter referred to as GTO) 12.
-17 are connected in a 6-phase bridge, with diodes 18-23 connected to each of GT012-17.
are connected in antiparallel.

A four-quadrant chip 100 is inserted between a smoothing circuit consisting of a DC reactor 4 and a capacitor 5 and a power converter 6.

The four-quadrant chopper 100 includes GTOlol and a diode 111 . GTO102 and a diode 112° connected in anti-parallel to this GTO103 and a diode 113 connected in anti-parallel to this. GTO104
and a diode 114 connected in antiparallel to this. GTOl
It has a smoothing reactor 200 inserted between the connection point of ol and 102 and the connection point of GTO 103 and 104,
The series circuit of Olol and 102 is connected between the terminals of the capacitor 5, and the series circuit of GTO1Q3 and 104 is connected between the DC side terminals of the power converter 6.

121 is a filter capacitor inserted between the DC side terminals of the power converter 6;
A voltage detector 251 that detects the DC input voltage Vd of the power converter 6 is connected in parallel to the power converter 6 .

Reference numeral 241 denotes a current detector that detects the DC current "din (input current of the power converter 6) flowing through the DC circuit of the power converter 6.

A multiplier 26 calculates the input power P by multiplying the DC current Id in and the DC input voltage Vd.

The voltage controller 351 has an input reference voltage vd9 and a voltage detector 2.
51 detects the DC input voltage Vd of the power converter 6, and calculates this DC input voltage Vd as the input reference voltage Vd.
``''A gate control signal is created and supplied to the gate controller 361.

The gate controller 361 sends out a gate pulse with a pulse width corresponding to the magnitude of the gate control signal.

In this example, the storage/release power reference value is created by the overhead contact line 1S style reference generator 321 and the multiplier 261. The overhead line current reference generator 321 compares the voltage detection value Ed of the voltage detector 25 with the overhead line voltage reference value Ed''' to create a current reference value 1d''.

This current reference value Td'' is multiplied by the voltage detection value Ed in a multiplier 261.The output of this multiplier 261 is the stored/discharged power reference value P*, and the power controller 31 multiplies the multiplier 2
6 is compared with the converted power P of the power converter 6, which is the output of the power converter 6.

This power controller 31 has a required slip frequency Δf of the transparent machine 7.
1 and 32 are speed detectors that detect the rotational speed fo of the induction machine 70. , 33 is a frequency controller, to which the outputs of the power controller 31 and speed detector 32 are guided.

An oscillator 34 supplies a frequency signal corresponding to the frequency command signal f sent out by the frequency controller 33 to the gate pulse generator 35.

Next, the operation will be explained. This device uses overhead line voltage Fr.
When l is above a predetermined value, the overhead contact line 1 also takes in DC current Idin to store energy in the flywheel 8, and when l falls below a predetermined value, the current is released to the overhead contact line.

At the time of energy storage, the power converter 6 converts the DC input voltage Vd taken in through the four-quadrant tipper 100 into DC power and supplies it to the induction root, and the induction machine 7 is operated in full.

During this energy storage, the required slip frequency Δf of the induction machine T is calculated by the power controller 31 from the output of the multiplier 261 - and the output P of the multiplier 26 (actual converted power of the power converter 6), and is added. The oscillation frequency of the oscillator 34 changes according to the frequency f=Δf+fo, and the GTO 12~ of the power converter 6 is output from the gate pulse generator 35 according to the oscillation frequency.
A gate pulse is supplied to the gate of 1T, and GT012
17 are subjected to switching control, and the induction machine 7 and flywheel 8 store energy of electric power P'' (storage and release power reference value) from the overhead contact line 1.

Further, when dissipating the energy, the power converter 6 converts the stored energy of the flywheel 8 released through the induction machine 7 into DC power, and sends it to the overhead contact line 1 via the four-quadrant collar 100. Compensate for overhead line voltage drop.

Next, the operation of this four-quadrant chopper 100 will be explained. Assume that the flywheel 8 is now in a storage mode in which it absorbs energy from the overhead contact line 1.

At this time, if Ed>Vd'', the 4th quadrant Chiratsuba 10
0 is GTOlol is chopper driven and diode 11
2 is a step-down chopper that performs flywheel operation, and the DC input voltage Vd of the power converter 6 is the input reference voltage v.
d* The pressure drops dramatically.

Conversely, if Ed<Vd'', GTOl 01 is on,
GTOl 04 is chopper driven and diode 113
performs series diode operation and becomes a 5-power step-up chopper.

Furthermore, when the flywheel 8 is in the release mode in which it releases energy to the overhead contact line 1, if Ed≧Vd, then 4
Quadrant Choppa 100 has GTOI 03 on, GTO1
02 is driven by a chopper, and the diode 111 functions as a regenerative boost chopper that performs a series diode operation.

Conversely, if Ed<Vd, the GTO1Q3 is driven as a chopper, and the diode 114 becomes a regenerative step-down chopper that performs flywheel operation.

[Problem to be solved by the invention]

Since the braking device of the conventional 7-live wheel energy storage device is constructed as described above, the power source of the overhead contact line 1 is not reliable in order to perform constant voltage control using the chopper.

If the overhead contact line 1 is disconnected, the input voltage will not be maintained at a predetermined value, the output voltage of the power converter 6 will change, and the induction motor 7
A large reactive current flows between the power converter 6 and the power converter 6, making it impossible to continue operating the power converter 6.

Therefore, when decelerating the flywheel 8, the train i
! ! 1) Energy must be released, and if there is no power on the overhead contact line at night, etc., there is nothing to absorb the released energy, so the flywheel cannot be slowed down and stopped. There was a point.

This invention was made to solve the above problems, and by decelerating the flywheel without releasing energy to the DC power source, the flywheel can be stopped at will regardless of the state of the DC power source. It is an object of the present invention to provide a braking device for a flywheel energy storage device that can

[Means to solve the problem]

A braking device for a flywheel energy storage device according to the present invention includes a first switch that disconnects a chopper from a DC power source, a braking resistor that consumes regenerative power of the chopper, and a second switch for turning on this braking resistor. A switch, a computing unit that detects changes in the input voltage of the power converter, a frequency controller that adds the output of this computing unit and the frequency command of the power converter to control the switching frequency of the power converter, and a regenerative The system is equipped with a stop sequence generator that controls the frequency controller and controls the opening and closing of the switch during braking.

[For production]

During regenerative braking in this invention, the first switch is opened to disconnect the chopper from the DC power supply, the second switch is closed and the braking resistor is turned on, and during this time the change in the input voltage of the power converter is calculated. The input voltage of the power converter is controlled by the frequency controller based on the addition of the output of this calculator and the frequency command of the power converter, thereby suppressing excessive reactive current between the power converter and the induction machine. At the same time, the chopper restarts and the flywheel is stopped while the chopper's regenerated power is consumed by the braking resistor, eliminating the need for energy absorption by the DC power source.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. 1st
In the figure, 1~8.12~23.25.26.31~
35,100~104,111~114.121,20
0,241,251,261°321.351', 36
The portion indicated by 1 is the same as that in FIG. That is, the parts described below are added to the configuration of FIG. 3 in FIG.

That is, 41 is the braking resistance, and the 4-quadrant chopper is 1000
This is for consuming regenerative power.

Reference numeral 40 denotes a second switch for connecting the braking resistor 41 to the input side of the four-quadrant chopper 100. In addition, in FIG. 1, the switch indicated by 3 will be referred to as a first switch.

42 is the input voltage Vd of the power converter 6 and the input reference voltage vd
43 is a switching relay that switches the stored and discharged power reference P* to O, and this switching relay 43 is connected to the output terminal of the multiplier 261 and the power control unit. 310 input terminal.

Further, 44 is a switching relay that switches the slip frequency Δf added by the frequency controller 33 from the output of the power controller 31 to the output of the calculator 42, and the output terminal of the power controller 31 and the output terminal of the calculator 42 and the frequency controller 330 input terminal.

45 is a switching relay that switches the rotational speed fo, which is the other signal added by the frequency controller 33, to the output of the ramp generator 47; 46 is the rotational speed f, which is the input signal to the ramp generator 470; A switching relay 48 is a switching relay that turns on and off the gate pulse of the four-quadrant chopper 100, and these switching relay contacts are controlled to be turned on and off by a stop sequence generator 50.

By turning on the stop button 50a, the stop sequence generator 50 turns on the switching relay 43, and turns on the delay circuit 51.
through the first switch 3. Switching relay 48 to 0FFL,
The switching relay 44 is turned on and is set to 5, and
When the first switch 3 is closed, the second switch 40 is closed.
N, and accordingly, switching relays 48, 45.4
6 is turned ON. The configuration of other parts is the same as the conventional example shown in FIG.

Next, the operation will be explained. FIG. 2 is a flowchart showing the flow of operation of the embodiment shown in FIG.

First, when the stop button 50a is pressed in step S'TI,
The switching relay 43 is turned on, and the power reference value P*, which is the input of the power controller 31, is set to zero. As a result, in step ST2, the power controller 31 calculates the required slip frequency Δf such that the conversion power P of the power converter 6 becomes 0, and adds the calculation result and the rotational speed fo to the frequency controller 33. The oscillation frequency of the oscillator 34 is controlled.

This oscillation frequency passes through the gate pulse generator 35 to control the tip frequency of the GTO of the power converter 6, and as a result, the slip of the induction machine 7 is controlled.

As a result, only a small amount of loss in the power converter 6 is regenerated from the flywheel 8 via the induction machine 7, and a balanced operation state in which the output current of the four-quadrant chopper 100 is O is created.

At the same time, the timer of the delay circuit 51 is activated in step ST3, and when this timer times out after a predetermined time (step 5T4), the switching relay 48 is turned off, and in step ST5, the GTOs 101 to 10 of the four-quadrant chipper 100
4 is chopper gate 0FFt,, 4 quadrant ChiM Tsuba 100
stops working.

At this point, the output current of the four-quadrant chopper 100 is in a balanced state of O, so no transient fluctuations in the input voltage occur. 1st at the same time as OF'F of 4 quadrant Chiyoppa 100
A command to open the switch 3 is issued. As a result, the overhead contact line 1 is released from the four-quadrant chopper 100 in step ST6.

Furthermore, the switching relay 44 is turned on, and step ST7
Then, the slip frequency Δf becomes the output of the calculator 42, power control is stopped, and the slip frequency Δf is determined instead according to the command value of the input voltage Vd, that is, the deviation from the input reference voltage vdk.

In other words, when Vd>Vd'', the slip frequency △f is made positive and a positive slip is given to the induction machine 7Vc.As a result, the induction machine 7 enters the power running state, and power flows out from the power converter 6. , This power discharges the capacitor 121, and the input voltage Vd of the power converter 6 decreases.

Conversely, when Vd (Vd''), the slip frequency Δf
Since is negative, the induction machine 7 is given a negative slip and enters a regenerative state. As a result, power flows into the power converter 6, the capacitor 121 is charged with this power, and the input voltage V
d rises. In this way, the input voltage Vd is maintained so as not to deviate from the predetermined value Vd.

Next, when it is confirmed in step ST8 that opening of the first switch 3 is completed, a command to close the second switch 400 is issued to close the braking resistor 41. When the second switch 400 is closed (step ST9), the switching relays 48, 45, 46 are turned on (step 5TIO)
.

As a result, step STY 1 has a 4-quadrant chitsupa of 100
The chopper gate is turned on, the chipper 100 starts operating, and constant voltage control becomes possible again by the four-quadrant chipper 100. At the same time, in step 5T12, the frequency command f,
The signal on which the calculation is performed switches from the rotational speed f0 to the output of the ramp generator 47.

The input of the ramp generator 47 is previously the rotational speed f. Therefore, at the time of switching, the lamp output -f.

'', and the switch is switched.

Thereafter, in step STI 2, the lamp input is switched to 0, and the lamp output begins to decrease at a predetermined deceleration rate. As a result, the frequency command f also decreases, fs<f,
In this case, the slip of the induction machine 7 becomes negative and it enters a regenerative state.

The energy of the flywheel 8 is then regenerated to the power converter 6.

This regenerated power charges the capacitor 121, and the input voltage V
d is increased, but it is discharged to the braking resistor 41 by constant voltage control of the four-quadrant chopper 100.

In other words, when vd > Vd”, the gate pulse width of GTO 103 increases and the charge of capacitor 121 is
l 03, reactor 200. Diode 111. Reactor 4. Second switch 40. Discharge is caused through the route of the braking resistor 41. In this way, the energy of the flywheel 8 is consumed by the braking resistor 41 and a stop is effected.

The switching relay 44 is in the ON state during the stopping process, but as long as the constant voltage control of the chopper is working normally as described above, Vd=Vd'', so the output Δf is normally O.
It is.

In the above embodiment, the stop sequence generator 50 was explained as a relay or a gate logic circuit, but
By converting the chart into software and implementing it with a microprocessor, C has the same effect.

Moreover, although the above-mentioned embodiment explained the case where it is connected to the overhead contact line 1, the same effect can be obtained even if a DC power source such as a DC transmission line or a DC bus of a factory power supply is used instead of the overhead contact line 10.

Further, the chopper is not limited to a four-quadrant chopper, but by limiting the operating area, the same effect can be achieved even when a three-quadrant chopper or a two-quadrant chopper is used.

Further, in the above embodiment, the signal compared by the power controller is treated as electric power, but there is no problem if it is treated as electric current. That is, the multiplier 261 is omitted, the command value of the current Id is directly given, and the feedback signal is -CXd=”
Even if d is used, the operation will be exactly the same as d.

〔Effect of the invention〕

As described above, according to the present invention, when the flywheel is stopped, first, the power converter input is controlled to O, and then the chopper is controlled to 0FFu, and at the same time, the slip of the induction machine is controlled by the change in the power converter input voltage, After that, a braking resistor is applied, and the switch is turned on to allow the braking resistor to consume energy and stop the flywheel, so it is possible to suppress fluctuations in the input voltage of the power converter even after the DC power supply is disconnected. In addition, there is an effect that the flywheel can be braked and stopped at any time regardless of the state of the DC power source.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing the configuration of a braking device of a flywheel energy storage device according to an embodiment of the present invention, FIG. 2 is a flowchart showing the flow of operation of the present invention, and FIG. 3 is a circuit diagram showing a conventional flywheel energy storage device. It is a block diagram of the braking device of an energy storage device. 1 is an overhead contact line (DC power supply), 3 is a first switch, 6 is a power converter, 7 is an induction machine, 8 is a flywheel, 33 is a frequency controller, 40 is a second switch, 41 is a brake resistance, 42
50 is a stop sequence generator, and 100 is a chopper. In addition, in the figures, the same reference numerals indicate the same or equivalent parts. Patent Applicant Mitsubishi Electric Co., Ltd. Agent Patent Attorney 1) Hiroshi Sawa:・Ya (2 others)""' Figure 1 Figure 2 Figure 3 Procedural amendment (voluntary)

Claims (1)

[Claims] A chopper that is connected to a DC power supply and performs step-up chopper operation and step-down chopper operation to generate a variable DC voltage; a power converter that is connected to this chopper and converts DC into alternating current with a variable frequency; an induction machine,
a flywheel connected to the induction machine; a frequency controller that controls the input power of the power converter; a first switch that disconnects the chopper from a DC power source; and a brake for the chopper instead of the DC power source. a second switch that turns on a resistor; a calculator that detects a change in the variable DC voltage and calculates a voltage deviation; and a frequency controller that reduces the converted power of the power converter to zero when the flywheel is stopped.
After that, the operation of the chopper is stopped, and after adding the voltage deviation to the output frequency of the power converter, the first switch is opened and the second switch is closed, and at the same time, the chopper starts operating. and a stop sequence generator that performs a sequence operation to restart the frequency controller and reduce the output frequency of the power converter at a predetermined deceleration rate.