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How to operate the generator in parallel working mode?


The generator when operating in parallel mode with a different machine, or multiple machines together into a common power grid connection always requires a number of conditions. One of the conditions is that the machines have to operate in sync with each other.

When starting a generator, the speed of the air, the frequency and the voltage of the machine always starts from 0. After the conditions of the frequency and voltage of the air is equal to the value of the quota, must have the connect the machines together. This movement is called synchronization.

One can draw a synchronous generator with a different machine, a generator with a grid cell, or 2 are the same grid cell are together.
The conditions of synchronization generator
Conditions on the frequency: 2 air must be equal to each other, or frequency frequency machines must be equal to the frequency of the grid.
Voltage requirements: 2 units to the same voltage with each other, or the machine voltage must be equal to the voltage lứoi.
Phase conditions: 2 units to the same phase sequence and phase angle must match.

We see condition 1 and condition 3 may seem to contradict each other. Because if desired for phase angle of 2 overlapping side, then you have to adjust the frequency. That has to adjust the frequency, the frequency can not equal. Also if you want to keep for 2 equal frequency, then everlasting adjustable phase angle ligament. So the actual condition is:
Conditions on the frequency

The frequency of two approximately equal. False distinction between Delta f. df is how much depending on whether certain speed and automatic power draw, relays or relays against the false peace.

Usually, people adjust to the df has value > 0, meaning that the frequency of higher frequency machine a bit. So when the peace on the grid, the player will be Green Grid frequency back, meaning the player will play a capacity be baby out grid point close cutting.

Some relays allow close even lower transmitter frequency the frequency of the grid. But drivers often adjust the frequency higher machine. If your frequency is lower than the grid, then after closing cutting machines, generators, grid frequency will be pulled for running faster, the capacity will be a little negative, work stations in motor mode.

Usually, the speed will certain FSNL speed (full speed no load) by 100.3% of the norm. And this is also the original frequency synchronization systems to put into operation. With a smaller df df to
allowed, then the country’s reconciliation Ministry, power off or on very little, does not affect the system.
Conditions on the voltage

They also allow the voltage differences are wrong a little bit than the grid voltage. And often people also adjust voltage generator for defined by or over a little grid, so that when U close the infinite capacity of the power of the slightly better 0. For the voltage you can adjust to your exact mesh U = U without problems.

Phase conditions

This is mandatory, and is absolutely correct. Mix order, typically only test a first time when installing. From then on, no one will check what to do, except if there is something to work things out and insert it again.

Because of having to adjust the frequency, the frequency does not equal 2. Thus the phase angle will change continuously according to the beat frequency = 2 ‘s frequency. The relays must predict the exact moment zero phase angle, knowing in advance the time of cutting, and must give an output signal sync time MC closed by that time. Usually about 100 ms below to a few hundred ms.

The conditions on the voltage and frequency conditions, can check by direct measurement instruments such as voltmeters, design frequency. But the conditions of phase sequence and phase: phase (phase deviation angle) need to check more stringency.

The phase of the two isotopes grid system

For fractional systems, biodegradation, the grid system of the isotope mix has been determined as soon as the design. However due to the distortions of the voltage on the line, on Christmas day of short circuit of transformer returns, due to the collaboration of the transformers in circuits not good round and by the distribution of the load before closing, so the phase angle between the cutting head can be non-zero. But often is little changed in a short time. In this case, close the cutter will not cause big effects, except a few which have the ability to overload.

For some the region associated with the grid system with 1 single line or multiple lines, but due to the collapse of entire issues, then close again, phase angle will no longer 0. When that angle will change, constantly, for 2 at the frequency will no longer equal. Close the air cut at that are full of conditions of frequency such as synchronization generator. And often difficult, harder than synchronization generator. To change the frequency of one of the two can not impact the spot, which is a remote contact.

To ensure the isotope mix, on the driver circuit-breakers should be installed in a synchronization, relays or relays against false.

For the first case, the relay can be certain about allowing pretty wide: phase angle may be wrong from 5 to 10 degrees, allowing the wrong voltage from 5 to 10%. Can allow or disallow plays in case the live line dead bus, bus live dead line … some longer cutter allows close both in case of dead line dead bus.

As for the second case, the request would probably be more stringency.

The synchronization scheme, according to the book’s simple in theory, using the dark lights, bright lights, rotating lights … or a few more counters.
Synchronization on the generator bars

Diagram of a Republic to stick the picture as below (already filters out most of the surrounding circuits, the circuit would not stick to the synchronization circuit)

In the image above, the bottom connection on the 3 phases of the ABC stations. The top connection on ABC Radio’s the thing. Assuming that bar players and players are measured by a measuring transformer connecting fig. V/v. (this diagram can be confused with triangle openings, but not).

People just need to connect the land phase b of the secondary side, and connects the a1, b1 on one side of the Sync column, a2, b2 on the other side of the column. So of course b1 and b2 are connected.

Can see when Sync generators together:

-a1 voltage equal to a2, (V1 = V2)

-the frequency of a1 with a2 (Hz1 Hz2 =),

-A1 phase Angle coincides with the a2, (SS only 12 hours)

-2 light bulbs on the same column sets off.

Sync relays, there are 2 types, the relay is automatically synchronized and sync control relays (against the peace of false). When the three conditions on the deal, then the relay will export an ordered close cutting.

Synchronization to the generator through transformers

However, in current practice, at least when people connect several transmitters on a bar of the transmitter. The general tendency is to design the generator-transformer. The picture below shows the transmitter connected to the transformer power through cutting the top of the pole.
Transformers star/Delta connections 1 hour

In this case, to save, people will not put the transformers medium voltage measurement in the midst of cutting machines and transformers. That always use the high pressure transducer for comparison.

Similarly, below, also transformers star triangle 1 hour. But the generator is connected directly with the transformers. Cutting power to the high-placed Republic. People also do not put the measurement transformer between your cut and transformers. That always use the measuring transformers of generators to compare.

When such a comparison circuit, the advantage is saving a measurement transformer, which is very expensive, and captured the place. But will arise out 2 the problem is that the amplitude and phase.

About brewing, converters of pressure usually has wire star/triangle 1 hour or 12 hour. That is when, the high-voltage and medium-voltage will deflect one another 30 degrees. So, to get the appropriate signal.

As pictured above, is the high-voltage power grab a2-n and the low-voltage wire voltage signal obtained a1-b1. How to obtain so will compensate pha stars whether primary voltage deviation of 30 degrees each, but the secondary voltage taken into the system also draw phase.

About the magnitude, due to the high voltage phase should take reduced root 3 times. Moreover, the Bhikkhu of measurement transformers are not fully coordinated with the power transformer ratio. So have to use an extra measurement transformers in 1 in 2 sides. Usually placed in the phase voltage, and take that up to the full level of protection relays.

Transformers Star/Delta connections 11 hours

The picture below is similar to 2 pictures above, but connect to transformers star/Delta Force 11 hours.

The high-voltage voltage phase is taken, c2-n2, and the Central world retrieved the voltage line c1-b1

Synchronization low voltage generator by hand

Currently most of the generator has a system of automatic synchronization. The section between like the synchronization operations manually only for reference in order to clarify the principle of synchronization.

Case of need synchronization a diesel generator on the net. This generator and the grid are earthed neutral.

Check the phase sequence

First, to ensure both the correct phase sequence. You can check the phase sequence by the following way:

1/. Phase sequence meter.

2/. check out the orientation of the motor on the bar when the electric grid. Then open the grid out, close your player on, and tallies the phase order.

3/. Use 2 voltmeter to measure and compare before synchronization (using the voltmeter needle). A measure between phase and phase A of A of a grid. The other gauges turn between B and B, then C and C NET. When running, the clock will change from 0 to 2 times the Upha shit. But the mandatory condition is that they must increase and decrease at the same time. Truth is precisely to increase max at the same time, and fell 0. When the two top breaker will correct order mixed together. In case of failure at the same time, you try it again: a clock still measure A and a. remaining clocks measure B and C, or C and B. If in this case it back up and down evenly, then surely is the reverse order of phase two.

After checking the correct phase sequence, can connect the circuit surely for things, and not have to worry about the order of later phases.

Check the voltage

This is simple, It’s just let meter 2 Volt fitted at either end. However you can use a volt meter to measure between phase and phase A of the machine of a mesh. When the voltage down low for the phase deviation angle = 0. If the two equal heads will down to 0V. If the other will have 0V.

Check frequency
Usually the frequency of the machine and the grid all have brass Tiger measured. But to know exactly how much each deviation frequency 2 cannot be based and 2 watches. One can define the frequency deviation in many ways:

1/. Based on the next synchronization, if available. Next sync essentially is a deviation phase angle meter between the two power sources. If two completely equal frequency then the needle will stand still. Because the deviation phase angle will get fixed. If there is deviation of frequency then the needle will move. Depending on how much the frequency deviation, that kim will move fast or slow. Assuming each deviation frequency Hz 2, then the needle will come out round 1 1 seconds. (Beat frequency = 1 Hz) If your speed is high, the frequency of higher frequency machine, the needle will turn clockwise. If the frequency is lower than the machine, the needle will roll back.

2/. Based on the lamp. (Download map lights will draw back, but like diagrams in textbooks).

Look at the speed of light the lamp, that know the frequency deviation. However, this does not indicate any higher than the frequency. You can guess what any higher than the frequency by looking at the response of the lamp under the operation. You manipulate the rise or fall in the frequency of air for light speed, the lower the lights as we put together the frequency. It is best to adjust for beat frequency of about 0.2 to 0.1 Hz, i.e. the flashing speed from 5 to 10 seconds.

3/. Based on its experience. This is when synchronization experience right on your computer. The grid level for neon lights (the old days often have handheld stroboscope lamp). If no, use fluorescent or mercury lamps. When this light shone on a rotating shaft, will feel the shaft which rotates more slowly, or stand, or direction. Depending on the frequency deviation and speed machine. When frequency deviation = 0 then saw seems like the shaft is standing still. The frequency of air lower then it seems the shaft rotating. Air frequency higher then it seems positive axial dimensions. However this is just experience, and is not recommended to use, due to the problems of labor protection.

Check the phase deviation angle

Phase deviation angle can be identified by:

1/. the location of the synchronized. When the needle in the highest position is usually called a 12-hour position, is at zero phase angle. 2/. the brightness of the lamp: when the lights Dim or bright, really, is at the corner of phase 0. However this is not very accurate, because of the thermal inertia of the filament bulbs, and the ability to distinguish the dark glow of the human eye. 3/. value of measuring voltmeter. Value at min is the phase angle = 0.

After checking all of these conditions:
U air is approximately equal to U.
Your frequency is approximately equal to the frequency of the grid, but slightly higher. (Synchronous design rotated the needle clockwise, and spin very slow).
Phase angle towards 0: lights off, synchronize the design on the road from 11 hours to 12 hours the voltmeter on the way about min, then can manipulate the close.

Usually one can allow closed a little early, to compensate for the slow operation of VHV, and compensate for the closing speed of the cutter, breaker. Try not to be late

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