JPS5929447B2 - How to distinguish between power running and regenerative operation - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for determining whether a power running operation is a regenerative operation.

Conventionally, a method for regenerating regenerative power generated from a regenerative car of an electric railway to the alternating current side uses one forward converter and one inverse converter, or a plurality of each converter.

A method is being considered in which one or more thyristor converters are used to provide forward/reverse performance for power regeneration.
In this case, in order to switch from the forward converter state to the inverse converter state, it is necessary to detect that the feeding system is in the regenerative state, and generally the substation bus voltage is detected. However, this method of detecting the substation bus voltage to determine whether it is during power running or regeneration has the following problems in voltage detection.

(1) Since the substation bus voltage includes rectification ripples from the forward converter, it is necessary to find an average value using a filter.

This causes a time delay in detection by the filter. (2
) The set value of the detection voltage must be set high enough to avoid the influence of DC voltage fluctuations due to power fluctuations and load fluctuations of the forward converter, or a compensation circuit is required.

The former leads to detection time delays, and the latter is complicated and expensive. The present invention was made in order to solve these problems. Specifically, the present invention converts commercial frequency AC power into DC power and supplies it to the feeder line as power running power, and converts the regenerative power from the regenerative vehicle into AC power. A converting device is installed in a substation that reversely converts the power and regenerates it to the commercial frequency power supply side, and the converting device determines whether to perform power running operation or regenerative operation based on the voltage of the feeder line. The converter detects the DC output voltage of the converter, extracts the maximum value and minimum value of the pulsating current level of the detected voltage, and converts the converter based on these maximum value signals and minimum value signals. The present invention aims to provide a method for determining whether power running or regenerative operation is performed, which is characterized by discriminating between power running and regenerative operation, and will be described below using examples.

Before explaining this embodiment, the following can be said by focusing on the waveform of the DC output (DC feeding circuit voltage) of the converter that converts AC from the busbar of a substation into DC.

Figures 1a-d are voltage waveforms of the DC output of the converter,
FIG. 1A shows a waveform when a power running load is supplied, and the part A shows a drop in the waveform due to phase control and commutation overlap.

In addition, Figure 1b shows the waveform during no-load power running, and Figure 1c shows the waveform at the start of regeneration. Become.
When the waveform becomes d in FIG. 1, the ripples are masked by the regenerative voltage, resulting in a smooth waveform c. Therefore, by paying attention to the pulsating flow waveforms as shown in FIGS. 1C and 2d, it is possible to determine whether or not the system is in a regenerative state. The present invention has been made in view of this point, and will be described in detail below based on the embodiment shown in FIG.

FIG. 2 shows an embodiment of the method for determining power running and regenerative operation according to the present invention. In the figure, 1 is a converter installed in a substation, and this converter 1 3
Converts phase AC input (commercial frequency AC power) to DC power and supplies it to feeder lines as power running power, and converts the regenerative power from the regenerative vehicle back to AC power on the commercial frequency power supply side (substation side) It is something that can be regenerated. The output voltage (feeder line voltage) of the converter 1 is divided by a voltage divider 4 consisting of resistors 2 and 3,
The voltage divided by the voltage divider 4 (divided voltage of the resistor 3) is converted into a digital value by an analog-to-digital converter (hereinafter referred to as an A/D converter) 5, and this output is converted to an isolation transformer. is led to a storage device 7 via a device 6. This storage device 7 stores, for example, the DC output voltage waveform of the converter 1 at a maximum value VMA as shown in FIG. 1 according to the phase control angle α.
Since Xα and the minimum value MINa are respectively displayed, in order to incorporate these quantities, digital values obtained by analog-to-digital conversion for one cycle of the DC output voltage, that is, the cycle of the minimum frequency of the rectification ripple, are stored. 8 is a phase control unit for controlling firing of each thyristor element group of the converter 1, and 9 is a digital representation of analog information indicating at what phase control angle α the gate signal group output from the phase control unit 8 is emitted. An A/D converter for converting into a signal, 10 is a discrimination circuit, and this discrimination circuit 10 determines the maximum peak value VMAX and the minimum peak value in a period of one cycle from the digital information of the rectified ripple taken in from the storage device 7. VMIN and are respectively taken out, and each of these pieces of information is stored in the storage circuits 11 and 12, respectively.

13 is the instantaneous maximum value VMAX in the range of phase control angle α
This first arithmetic circuit 13 calculates the maximum peak value signal V derived from the memory circuit 11.
MAX and phase control angle signal α derived from A/D converter 9
Based on, VMAXa=VMAXsin (α1000 animals) (
However, P is the number of rectification phases of the converter 1, which is P-6 in this embodiment.

) to obtain VMAXa. 14 is a second arithmetic circuit, and this second arithmetic circuit 14 receives the maximum peak value signal VMAX and A/A derived from the memory circuit 11.
Based on the phase control angle signal α derived from the D converter 9, V
MlNa=VMAXOO5 (α10) (where P is the number of rectification phases of the converter 1, and in this example, P=6.

) to find the instantaneous minimum value VMINa in the range of the phase control angle α. 15 is a third arithmetic circuit for determining the first jump voltage Vα, and this third arithmetic circuit 15 is connected to each of the first and second arithmetic circuits 13, 1.
Based on the instantaneous maximum value signal VMAXa and the instantaneous minimum value signal VMlNa derived from 4, Vα-VMAXa-VMina
The desired Vα is obtained by performing the following calculation.

16 is a fourth arithmetic circuit for determining the second jump voltage Va5, and this fourth arithmetic circuit 16 is derived from the instantaneous maximum value signal VMAXa derived from the first arithmetic circuit 13 and the memory circuit 12. With the minimum peak value signal VMIN (MA
A desired Va7 is obtained by performing the calculation (Xa-VMIN).

Reference numeral 17 denotes a determination circuit, which determines Va'/Vα<K (where K is a constant In order to prevent detection malfunction, 0.95 K<1.
According to the judgment formula (prescribed in advance to be in the range of 0), if the ratio of Va'/Vα is larger than K, power running is performed, and on the other hand, if it is smaller than K, regenerative operation is performed. Based on the determined output of 0, phase control of the converter 1 for regenerative operation or power running is performed.

Here, the phase control of the regenerative operation is control to advance the phase of the converter 1 toward the inverse conversion region. The operation of this embodiment configured as above will be described below.

Output voltage of converter 1 installed in the substation (feeder line voltage)
The waveform is shown in FIG.

The output voltage of the converter 1 is divided by a voltage divider 4, and the divided voltage of a resistor 3 is A/D converted by an A/D converter 5, and is led to a storage device 7 via an isolation transformer 6. The device 7 stores the A/D converted digital value for one cycle of the DC output voltage, ie, the cycle of the minimum frequency of the rectification ripple. The discrimination circuit 10 takes out the maximum wave height value VMAX and the minimum wave height value VMIN as shown in FIG. is the maximum wave height value VMAX,
The minimum peak value MIN is stored in the storage circuit 12. 1st
The arithmetic circuit 13 A/D converts the maximum peak value signal derived from the memory circuit 11 and the phase control angle α (analog information) of the gate signal group output from the phase control unit 8 to the converter 1.
Based on the phase control angle signal α converted into a digital signal by the converter 9, the calculation MAX3ln (α1001) is performed to obtain the instantaneous maximum value VMAX in the range of the phase control angle α.
Find a.

The second arithmetic circuit 14 performs an operation VMAXOO5 (α 10th order) based on the maximum peak value signal VMAX derived from the memory circuit 11 (and the phase control angle signal α derived from the 5A/D converter 9). , find the instantaneous minimum value VMINa in the range of phase control angle α.These VMAXO, VMINa
is a calculated value and corresponds to the values shown in Fig. 1 a to c, and during power running (Fig. 1 A, b), VMINa = VMIN,
During regeneration (Fig. 1c), VMIN'S. Becomes VMINa. The third arithmetic circuit 15 is connected to each of the first and second arithmetic circuits 13.
, 14, based on the instantaneous maximum value signal VMAXa and the instantaneous minimum value signal VMINct (MAXct - VMIN
a) Perform the following calculation to find α as shown in FIG. 1 a-c.

Further, the fourth arithmetic circuit 16 uses the instantaneous maximum value signal VMAXa derived from the first arithmetic circuit 13 and the minimum peak value signal VMlN derived from the memory circuit 12 (VMAXa-VMI
Va5 as shown in Fig. 1 a-c by performing the calculation N)
seek. During power running, Vα=Va7 in 0η figures (A, b), and Vct'S, α5 during regeneration (FIG. 1c).
The determination circuit 17 determines Va'/V based on the jump voltage signals Vα and Va5 derived from the third and fourth arithmetic circuits 15 and 16.
It is determined whether the determination formula α<K holds true or not, and the corresponding determination output 0 is sent out.
Vα=Vct' in Figure a) and during no-load power running (Figure 1 b)
Therefore, Va5/Vα=1(>K) and power running (
It is determined that the vehicle is running (powering state). Furthermore, when regeneration is started, the feeder line voltage on the output side of converter 1 becomes as shown in Figure 1c, and V
a+Va5 and Va5<Vα, the above determination formula is established, and it is determined that the regeneration state is present. Therefore, when the above-mentioned judgment formula is established during power running at first, a judgment output for detecting the regeneration state is sent as the output of the judgment circuit 17, and based on this judgment output, the phase control section 8 immediately reverses the phase of the converter 1. Control is performed to advance to the conversion region side, and the transition from power running operation to regenerative operation is performed. Therefore, the regenerated power from the vehicle is reversely converted into alternating current power by the converter 1 and regenerated to the commercial frequency power source. Note that in the determination circuit 17, when the determination formula is not established, the phase control unit 8
causes the converter 1 to continue powering operation. On the other hand, when regenerative operation is being performed and a judgment output of power running state detection is sent as the output of the judgment circuit 17, the phase control unit 8 immediately changes the phase of the converter 1 to the forward conversion region side based on this judgment output. Performs control to advance the vehicle and transitions to power running. Therefore, AC power at a commercial frequency is converted to DC power by the converter 1, and is supplied to the feeder line as running power. Power running is continued as long as the judgment output of the judgment circuit 17 does not change. When the present invention described above is used, there is no effect of an increase in the power supply voltage of the converter, and therefore there is no delay in detection time caused by this.

Furthermore, according to the present invention, even if the output of the converter includes rectification ripples, there is no need to use a filter to obtain an average value, so there is no delay in detection time caused by the filter. Furthermore, according to the present invention, regarding the speed of detection of regeneration or power generation, whereas in the conventional voltage detection method there is a time delay of at least 1 radian due to the filter, Only one judgment operation is required based on the data for each cycle, so the time delay is 1/3 of the conventional voltage detection method.
, i.e., equal to 2π - radians, and the present invention can be applied to the conventional voltage P ~
Compared to other detection methods, this method has various effects such as being faster in detection time.

[Brief explanation of the drawing]

1A to 1D are waveform diagrams for explaining the present invention, and FIG. 2 is a configuration diagram showing one embodiment of the present invention, in which 1 is a converter, 2 and 3 are resistors, and 4 is a Voltage divider, 5 is A/D converter,
6 is an isolation transformer, 7 is a memory device, 8 is a phase control section, 9 is an A/D converter, 10 is a discrimination circuit, 11 and 12 are memory circuits, 13 is a first arithmetic circuit, and 14 is a second arithmetic circuit. Arithmetic circuit, 15
16 is a third arithmetic circuit, 16 is a fourth arithmetic circuit, and 17 is a determination circuit.

Claims (1)

[Claims] 1 Install a conversion device in the substation that converts commercial frequency AC power to DC power and supplies it to the feeder line as running power, and converts the regenerative power from the regenerative vehicle back to AC power and regenerates it to the commercial frequency power source. installed to determine whether the converter performs power running or regenerative operation based on the voltage of the feeder line, the detection is performed by detecting the DC output voltage of the converter. The maximum value and the minimum value of the voltage pulsating current level are respectively taken out, the phase control angle of the thyristor element group of the conversion device is detected, and the phase is determined based on this phase control angle and the maximum value of the pulsating current level. Determine the instantaneous maximum value and instantaneous minimum value in the range of the control angle, subtract the instantaneous minimum value from the instantaneous maximum value to determine the first jump voltage, and subtract the minimum value of the pulsating flow level from the instantaneous maximum value. A method for determining whether a power running or regenerative operation is performed, the method comprising determining a second jump voltage and determining whether the operation is a power running or a regenerative operation based on the ratio of the first jump voltage and the second jump voltage.