JPH0277340A - Control circuit of regeneration power absorbing device - Google Patents

Abstract

PURPOSE:To absorb only the regeneration energy from a D/C electric car securely by providing a device to generate a pattern approximate to the D/C output voltage wave form of a rectifier, and a device to set the generated pattern as an absorption starting voltage at the upper side of the rectifier D/C output voltage. CONSTITUTION:A three-phase A/C voltage is picked up by providing a synchronous converter 21 at the A/C side of a rectifier 4, input to a synchronous shaping circuit 22, and the wave form is shaped from a sine wave to a square wave there. After correcting the phase of the square wave in a synchronous signal circuit 23, a pattern approximate to the D/C output voltage wave form of the rectifier 4 is generated in a pattern generating circuit 24 as an absorption starting voltage of the regeneration energy. On the other hand, since the D/C output voltage of the rectifier 4 is detected by a voltage detecting circuit 11, the detected voltage and the absorption starting voltage from the pattern generating circuit 24 are compared in a comparison circuit 13, the result is given to a chopper device 8 through a phase-shifting circuit 14, and when it is detected that the voltage is raised up to the absorption starting voltage or higher by the regeneration energy from the D/C electric car 7, the chopper device 8 is operated to absorb the energy to a resistor 9.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a control circuit for absorbing regenerative power generated during regenerative operation of a DC electric vehicle by a regenerative power absorption device installed in a substation. .

[Conventional technology]

FIG. 5 is a circuit diagram showing a conventional example of absorbing regenerative power from a DC electric vehicle.

In FIG. 5, three-phase AC power from a commercial power source 2 is input to a rectifier 4 via a transformer 3 that also serves as insulation and transforms to a desired voltage, and is converted into DC power by the rectifier 4. This DC power is supplied to the DC electric car 7 via the overhead wire 5, and serves as an energy source for the DC electric car 7 to drive.

When decelerating the DC electric vehicle 7 while it is running, an electrical braking method is often used. That is, if the kinetic energy of the running DC electric car 7 is converted into electrical energy and this electric energy is consumed by the resistor 9 installed in the substation via the overhead wire 5, the DC electric car 7 This results in braking operation in which kinetic energy decreases.

In order for the resistor 9 to absorb the electric power regenerated from the DC electric car 7 in this way, it is important to appropriately operate the chipper device 8 connected in series with the resistor 9.

That is, the voltage setting device 12 sets the absorption start voltage of the regenerated power, and this absorption start voltage is set to a value higher than the DC output voltage of the rectifier 4.

When the DC electric car 7 is decelerated (when regenerative power is generated, the voltage of the overhead wire 5 increases. Therefore, the voltage detector 11 installed on the DC side of the rectifier 4 detects this voltage increase, and this value is as described above. When the regulator 13 detects that the voltage exceeds the absorption start voltage of The resistor 9 absorbs the regenerated power, but when the DC electric car 7 decelerates to a desired speed, the generation of the regenerated power is stopped, the overhead line voltage decreases, and the chipper device 8 also stops its operation.

As mentioned above, when the DC electric car 7 regenerates electric power, the voltage of the overhead wire 5 increases, and if this voltage increase value is large, the equipment installed on the DC electric car 7 will ,
In particular, it does not threaten the insulation of semiconductor elements. Therefore, when this overhead line voltage exceeds a predetermined value, power regeneration is stopped to prevent equipment damage, and the voltage at which this power regeneration is stopped is called the regeneration expiration voltage.

FIG. 6 is a voltage waveform diagram when the difference between the DC output voltage of the rectifier and the regeneration expiration voltage is large.

In this FIG. 6, the symbol A is the waveform of the DC output voltage of the rectifier 4, and the rectifier 4 is
In the case of a phase full-wave rectifier, there are six pulsations during one cycle. Symbol B is the above-mentioned regeneration expiration voltage, and symbol C is the regeneration power absorption start voltage set by the voltage setting device 12, and this absorption start voltage C is naturally equal to the rectifier DC output voltage A and the regeneration expiration voltage. It is located between B and B.

In FIG. 5, a rectifier 4, a chopper device 8, a resistor 9
and the voltage detection circuit 11 is installed in the substation.
An overhead line impedance 6 exists between the DC electric car 7 and this substation, and the magnitude of this overhead line impedance 6 changes with the distance jl[D between the two. Therefore, if power regeneration is started when the DC electric car 7 is far from the substation, a large voltage drop will occur due to the overhead line impedance 6. Therefore, unless the voltage difference between the absorption start voltage C and the regeneration expiration voltage B shown in FIG. The value becomes higher than the regeneration expiration voltage B, and power regeneration operation becomes impossible.

[Problem to be solved by the invention]

In order to avoid the above-mentioned inconvenience, the value of the regeneration expiration voltage B can be set high, but in order to do so, the withstand voltage value of the equipment mounted on the DC electric car 7 must be increased, which increases the cost of the equipment. turn into. Therefore, the set value of the regeneration expiration voltage B is not set high, and the absorption start voltage C is set low, so that the voltage difference between the two is set to a value that can cover the voltage drop caused by the overhead wire impedance 6.

FIG. 7 is a voltage waveform diagram when the difference between the DC output voltage of the rectifier and the regeneration expiration voltage is small. Similarly to FIG. 6, symbol A is the vehicle output voltage waveform of the rectifier 4, and symbol B is the regeneration The expiry voltage, symbol C, is the absorption start voltage.

In this Fig. 7, the regeneration expiry voltage B is lower than that in Fig. 6 in order not to increase the withstand voltage value of the onboard equipment, but the difference between the regeneration expiration voltage B and the absorption start voltage C is secured to the same value as in the case of FIG. 6 so as to cover the voltage drop of the overhead wire impedance 6. Therefore, there is a time (T in Fig. 7) when this absorption start voltage B approaches the rectifier DC output voltage A and becomes higher than the absorption start voltage C near the pulsating peak value of the rectifier DC output voltage A. This causes a problem that the DC power outputted by the rectifier 4 is absorbed into the resistor 9, resulting in wasteful consumption of energy.

Therefore, the problem of this invention is to avoid increasing the regenerative expiration voltage (
In other words, the aim is to ensure that only the regenerated energy from the DC electric vehicle can be absorbed without increasing the withstand voltage value of the equipment.

[Means to solve the problem]

The above-mentioned problem can be solved according to the first solution of the present invention by means of generating a pattern that approximates the DC output voltage waveform of the rectifier, and by setting this generation pattern as an absorption start voltage above the rectifier DC output voltage. The problem is solved by providing a means to do this.

According to the second solution of the present invention, an auxiliary rectifier rectifies the commercial power supply voltage detected via an isolation transformer, and a DC output voltage is compared with a preset reference voltage, and the DC output voltage is A difference voltage detection means outputs a difference voltage between the DC output voltage and the reference voltage when the voltage exceeds the reference voltage, and absorption starts by adding the difference voltage to a preset absorption start voltage. and absorption start voltage correcting means for correcting the voltage.

[Effect]

The first solution of the present invention is that the DC power obtained by rectifying AC power includes pulsations, but the rectification method (
For example, the details of this pulsation can be determined by whether it is single-phase or tri-sum, half-wave rectification or full-wave rectification, so the waveform of the absorption start voltage set above the rectifier DC output voltage can be approximated to this pulsation waveform. In this way, even if this absorption start voltage approaches the rectifier DC output voltage, wasteful situations such as the regenerative energy absorbing device absorbing the DC power that is the output of the rectifier are eliminated.

In addition, the second solution of the present invention is that when the voltage on the rectifier DC side increases due to voltage fluctuations in the commercial power supply, the increase in the commercial power supply voltage from the reference voltage is detected and the absorption of this increased voltage is started. By adding it to the voltage, the voltage at which the power absorption means starts operating is increased in conjunction with the commercial power supply voltage to prevent unnecessary power consumption by the power absorption means, but the electric vehicle regenerates power. In this case, the absorption start voltage remains unchanged and the power absorption means is operated as before.

〔Example〕

FIG. 1 is a circuit diagram showing an embodiment corresponding to the first solving means of the present invention.

In FIG. 1, three-phase AC power from commercial power R2 is input to a rectifier 4 via a transformer 3,
DC power obtained by phase full-wave rectification is supplied to the DC electric car 7 via the overhead wire 5, and a regenerative energy absorption means consisting of a chipper device 8 and a resistor 9 is provided on the DC output side of the rectifier 4, as well as a voltage The detection circuit 11 is installed in the same manner as in the conventional circuit described in FIG. Also, the reference numeral 6 is the overhead line impedance.

In the present invention, a synchronous transformer 21 is provided on the AC side of the rectifier 4.
is installed to take out the three-phase AC voltage, which is sent to the synchronous shaping circuit 2.
2, the sine wave is shaped into a rectangular wave. After the phase of this rectangular wave is corrected in the synchronization signal circuit 23, the pattern generation circuit 24 generates a pattern that approximates the DC output voltage waveform of the rectifier 4. is generated as the regenerative energy absorption start voltage.

On the other hand, since the DC output voltage of the rectifier 4 is detected by the voltage detection circuit 11, this detected voltage and the pattern generation circuit 2
The comparator circuit 13 compares the absorption start voltage outputted by the DC electric car 7 with the absorption start voltage, and the result is sent to the chipper device 8 via the phase shift circuit 14. If detected, the chipper device 8 is operated to cause the resistor 9 to absorb energy.

The embodiment circuit shown in FIG. 1 is a circuit diagram for illustrating the gist of the present invention. Therefore, the circuit diagram shown in FIG. (e.g., countermeasures for

FIG. 2 is a voltage waveform diagram obtained in the embodiment circuit shown in FIG. 1, in which symbol A indicates the DC output voltage waveform of the rectifier 4, symbol B indicates the regeneration expiration voltage waveform, and symbol C indicates the absorption start voltage waveform. There is a hailstorm.

As shown in FIG. 2, due to the action of the pattern generation circuit 24, the waveform of the absorption start voltage C is a sine waveform similar to the waveform of the rectifier DC output voltage A, and since both are synchronized, the latter There is no risk that the chopper device 8 will be inadvertently activated due to the pulsation of the voltage, and the difference between the absorption start voltage C and the regeneration expiration voltage B can be set to a sufficiently large value.

FIG. 3 is another voltage waveform diagram obtained with the embodiment circuit shown in FIG. 1, but this diagram differs from FIG. 2 in that the waveform of the absorption starting voltage C is a triangular wave. It's different.

As shown in Fig. 3, it is easier to make the waveform of the absorption start voltage C into a triangular wave than to generate a sine waveform, and it is also possible to approximate the sine waveform and obtain almost the same effect. Because you can.

4th rf! J is a circuit diagram showing an embodiment corresponding to the second solving means of the present invention.

In FIG. 4, three-phase AC power from a commercial amount of
The DC power converted by is supplied to the DC electric car 7 via the overhead wire 5, and the DC output side of the rectifier 4 is equipped with a power absorption means consisting of a chopper device 8 and a resistor 59, as well as voltage detection. The arrangement of the circuit 11 is the same as in the conventional circuit described above in FIG. Also code 6
is also the overhead line impedance.

In this embodiment, a series circuit of an isolation transformer 121 and an auxiliary rectifier 122 is connected to the AC input side of the rectifier 4,
The voltage of the commercial power supply 2 is converted into direct current and detected.

On the other hand, the reference voltage setter 124 sets a reference voltage (for example, a voltage corresponding to the rated voltage) of the commercial power supply 2, and the differential voltage detector 123 detects the reference voltage set by the reference voltage setter 124. and the commercial power supply voltage from the auxiliary rectifier 122 are input, and the difference voltage between the two is detected. However, when the commercial power supply voltage is higher than the reference voltage, the differential voltage detector 123 outputs the differential voltage between the two,
When the commercial power supply voltage is lower than the reference voltage, zero is output.

The difference voltage thus obtained is added to the absorption start voltage set by the absorption start voltage setter 12 in the adder 125, and the result of this addition operation and the rectifier DC side voltage detected by the voltage detection circuit 11 are combined. , and if the rectifier DC side voltage is higher, the phase shift circuit 1
Since the operation signal is sent to the chopper device 8 through 4,
Resistor 9 starts absorbing power.

That is, based on the voltage output by the adder 125,
If the rectifier DC side voltage is lower, the chopper device 8 will not operate, and will only operate if it is higher. But lever adder 1
Is the output voltage of 25 based on the commercial power supply voltage? l! When the voltage is lower than the voltage, the voltage set by the absorption start voltage setter 12 is output as is (because the output of the differential voltage detector 23 is zero), so the voltage at which power and absorption starts is a relatively low value. However, when the commercial power supply voltage rises, the absorption start voltage is corrected to a correspondingly high value.

〔Effect of the invention〕

According to the first solution of the invention, the voltage waveform that sets the start of absorption of energy regenerated from the DC electric car is approximated by the same waveform as the rectifier DC output voltage waveform, or by a triangular wave. As a result, the regenerative energy absorption device can be reliably operated only during energy regeneration without increasing the regenerative expiry voltage, so there is no risk of absorbing excess energy other than regenerative energy, and there is no need to waste energy. It is effective in eliminating

Furthermore, according to the second solution of the present invention, when commercial AC power is rectified to obtain power for driving a DC electric vehicle,
When this DC electric car performs regenerative operation, the voltage increase in the overhead wires is absorbed by the power absorption means installed on the DC output side of the rectifier, but even when the voltage of the commercial power source increases, the voltage on the rectifier DC side increases, The operation of this power absorption means can be distinguished between fluctuations in the commercial power supply voltage and voltage rises due to regenerated power, and when the commercial power supply voltage rises, the operation start voltage of the power absorption means is increased. Since this power absorbing means can be prevented from wasting energy such as consuming unnecessary power, the power absorbing means can be miniaturized as a result.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing the first embodiment of the present invention, FIG. 2 is a voltage waveform diagram obtained by the embodiment circuit shown in FIG. 1,
FIG. 3 is another voltage waveform diagram obtained with the embodiment circuit shown in FIG. 1, FIG. 4 is a circuit diagram of the second embodiment of the present invention, and FIG. A circuit diagram showing a conventional example of absorbing regenerative energy. Figure 6 is a voltage waveform diagram when the difference between the DC output voltage of the rectifier and the regeneration expiration voltage is large. Figure 7 is the DC output voltage of the rectifier and the regeneration expiration voltage. FIG. 7 is a voltage waveform diagram when the difference with the voltage is small. 2... Commercial power supply, 3... Transformer, 4... Rectifier,
5... Overhead line, 6... Overhead line impedance, 7...
DC electric car, 8... Chimper device, 9... Resistor,
DESCRIPTION OF SYMBOLS 11... Voltage detection circuit, 12... Absorption start voltage setter, 13... Comparison circuit, 14... Phase shift circuit, 21...
...Synchronous transformer, 22...Synchronous shaping circuit, 23...
Synchronous signal circuit, 24... Pattern generation circuit, 121.
...Isolation transformer, 122...Auxiliary rectifier, 123...
・Differential voltage detector, 124...Reference voltage setter, 125
...adder. 152 Diagram A:, element six, Shichiriki Denkyu 0□ ′! 53 Figure 8h 156 Solid 7 Figure

Claims (1)

[Claims] 1) A means for absorbing regenerative power generated when the electric car performs regenerative operation is connected to the DC side of a rectifier that converts AC power from a commercial power source into DC power for driving the electric car. However, if the DC side voltage of this rectifier exceeds the absorption start voltage set above this voltage, in the device configured to activate the regenerative power absorption means, a pattern approximating the DC output voltage waveform of the rectifier is generated. What is claimed is: 1. A control circuit for a regenerative power absorbing device, comprising: means for generating the generated power; and means for setting the generated pattern as an absorption start voltage above a rectifier DC output voltage. 2) A means for absorbing regenerative power generated when the electric car performs regenerative operation is connected to the DC side of a rectifier that converts AC power from a commercial power source into DC power for driving the electric car, and the DC power of this rectifier is According to the second solution of the present invention, in a device configured to operate the regenerative power absorption means when the side voltage exceeds an absorption start voltage set above this voltage, An auxiliary rectifier rectifies the detected commercial power supply voltage, and the DC output voltage of this auxiliary rectifier is compared with a preset reference voltage, and when the DC output voltage exceeds the reference voltage, the DC output voltage and the reference voltage are and an absorption start voltage correcting means that corrects the absorption start voltage by adding the difference voltage to a preset absorption start voltage. A control circuit for a regenerative power absorption device.