Generator Synchronization - Theory and Simulation
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- เผยแพร่เมื่อ 4 ส.ค. 2024
- PENG1018 - Power Plant Simulation 2
Week 1 - Synchronization Pre-Job Brief
Theory on synchronization of generators, and simulation using Kongberg Neptune Simulators
Synchronization
Synchroscope
Diesel Generators
Steam Turbines
Governor
Frequency
Voltage Control
Georgian College Power Engineering
I am now 72 years old. For 34 years I worked as an operator in natural gas burning generating stations with steam turbines and generators. So a number of times over my career I synchronized these units to the line. The units I operated were built in the 1950s. The synchroscopes on these units had a circular dial with a pointer that would rotate. There was a mark at the very top of the dial to indicate proper synchronization. There was also an arrow pointing left that was labeled slow and an arrow point right labeled fast. It typically took a few minutes to synchronize a unit to the line. It was easy match the generator voltage to the line voltage. However it took some time using the governor to achieve the synchroscope pointer rotating slowly in the fast direction. This was because the turbine speed tended to drift. Once the machine was just a little faster than the electrical system I would watch the pointer and close the circuit breaker when the pointer was close to the top. This was to have the generator circuit breaker close when the pointer was at the top. Today it common place for electricity generators to be equipped with automatic synchronization that performs all these steps automatically. I also have seen what happens when generator synchronization is done poorly. There was a turbine generator unit where the speed governor did not work. The speed of this unit had to be controlled using the load limiter, which only pulsed open or close the turbine control valves. As a result the synchroscope would rotate very quickly in the fast direction or very quickly in the slow direction. As a result ideal turbine speed could not be achieved. So operators tried to do as best as they could. One time I was at the boiler control board and another operator at the electrical control board synchronizing the unit. I heard a loud bang as the electrical system suddenly snapped the unit into synchronization and the floor of the control room jumped. Amazingly the unit kept running without problems. Synchronizing a unit to the line this way can cause considerable damage to the turbine generator and should be avoided.
Hello sir,
I appreciate that you have shared your valuable experience.
Rahul Chauhan from India 🇮🇳
Very good explanation, the gear analogy and visual aids make it very easy to understand. Also being able to see it at work in a simulation helps apply it making it even more memorable.
the gear analogy comparing them with electrical variables ,makes this very simple to understand
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@Korbin Kylo instablaster ;)
The best explanation i ever attended such topic
Thanks brother for time and effort
Wow. I'm old school, 70's and 80's. I have been in many power stations where the operator matched voltages and everyone in the control room stares at the synchroscope clock and the 2 lights above it. When the turbine generator is goosed up a bit by the Raise/Lower switch so its slightly faster than the grid, the Operator waits until the lights go out as the scope needle hits the 12 o'clock position and he quickly hits the Breaker Close switch. The Operator immediately adds a bit of power by bumping up the Raise switch to prevent the reverse current relays from opening the breaker. Even back then the GE gas turbine generators has auto synchronization available as some peaking plants were unmanned and remotely operated. I was a Field Engineer for General Electric Co. in those days, worked in 17 countries.
"the Operator waits until the lights go out as the scope needle hits the 12 o'clock position and he quickly hits the Breaker Close switch."
The technique is know as the "dark lamp" method.
@@BedsitBob I recall, back in the early 70s, my elec eng lecturer, recounting an incident. Where a young technician, got the sync slightly wrong. It resulted in the grid forcing the generator into sync, and with such a mechanical shock, it sheared all the mounting bolts.
@@rjones6219 As I understand it, the generator should be running at a tiny bit higher (only a fraction of a cycle) than the grid, and the breaker should be closed just a fraction of a second before the generator lines up with the grid.
That allows it to run *into* sync, rather than running *out* of sync, if the breakers close a split second late.
Same method was used when I was in the navy back in the early 2000s
no circuit breakers
Some people are so bless with teaching skills. Thank you sir
One of the best instructed module I have taken. Thank you
Your training content and your presentation is excellent and much simpler for easy understanding.. thanks brother
found an answer...Post by Steven Chauvin: Once a generator is synchronized and placed on line, in parallel with other similar generators, the become “synchronous machines” (which means it will act as a generator (driving the load) or motor (acting as the load) at times). One of the generators in the group is designated to be the “master”. The other generators will synch to its speed and voltage. If one of the set begin to slow down, it will act as a “load” and so the other generators will “push” it. If it speeds up, the other generators will “pull”, becoming a load, pushing or pulling it back into synch.
Great power plant knowledge .. I would like to learn more from your channel
Thank you so much...I've been losing sleep wondering how Electric Vehicle batteries might replenish power to the grid.....
I have/had ZERO idea about electricity/grid/sync so your video was ENLIGHTENMENT....
Very informative sir. Keep making more educational videos
One of the the best videos
A very good Explanation. Thank you 💫
Really an excellent video
God bless this man🎉❤
very good explanation, thank you sir
Great job!
big fan of kongsberg simulator
I want to start by saying thank you for taking the time to make this educational video that was placed into simple terms. I am a power plant operator, 60MW unit and a 26MW unit. I have been trying to understand the reasoning behind the synch scope, I understand the basic principle of matching the grid before "pushing on" to it. Yet, most text is very convoluted and far from clear on understanding. I'm no engineer, I struggle when its written from an engineers or electricians perspective. So thank you for this again, very helpful video by using the "gears" as a visualization tool.
I would also like to ask, if you are still on the TH-cam, where can one find this simulator? Is that something anyone can access or is that a proprietary program?
Thank you for this.
Hi, I like your lecture. Thanks
Here in the UK, in the days before a nationwide grid, some local suppliers ran 25hz, and sometimes even 15hz, which was annoying for people running lighting off it.
Thanks for your sharing
Practically, I had seen rapid frequency variation before synchronising steam generator to the network. In steam turbine frequency variation give you fraction of time to close the breaker, as the governor doesn't give accurate response & control of steam.
superb
Very informative
Again thank you
Power generation source has many AC generators and electricity is transmitted out through the same electric wire not necessarily turned on together, then why the sine wave does not go out of phase with each other?
Thanks
A formality: At the slide at 2:42, you use quantities and unit symbols in the same formula. As in, you write, "Period = 1 / Hz". This is not proper form. It should be, "Period = 1 / Frequency". (Or, if you must, "s = 1 / Hz", but even that should only really be used in actual calculations with figures, not with the symbols standing on their own.)
Please, which simulation software to parallel generator?
Thanks for everything. Can we sync two gensets of different manufacturers. (One with electronic governor and other with mechanical governor) how to control the load share of them
In my sugar mill, I had 2 very different generators to sync. Sometimes they had electronic exciters, sometimes they had mechanical. Depended whether they were on normal or backup exciters. One generator started with a 1916 mechanical governor ( just fine for make lights for horses) but not very good at keeping 60hz. Later in the 90's it was upgraded to a computer governor. It could always be paralleled. The challenge was the balancing. At different load levels, one generator would take more load or less load. Just a bit of baby sitting if the loads change a bit. 1936 1000 KW and 1916 750 KW at 460V both off grid only. Both have been retired for about 8 years although the switchgear and syncro units are still in use.
Very useful information. 👍
What is the link to that software?
Note: in Canada, the electrons reverse direction 120 times a second. There are 60 complete cycles per second.
Very interesting! After the generator is synced and locked what prevents it from going out of phase as you increase the governor power? Inductive reactance or back EMF?
It dependes upon several factors: the impedance between the EMF and the grid (resistance and inductive reactance), the voltage values (of the grid and the EMF) and the load angle (which is the angle between the EMF and the grid voltage, also the angle between two magnetic poles of opposite polarity between the stator and rotor). But lets assume that the impedance and the voltage levels are constant (which is usually the case). Thus when the governor power is increased the load angle increases, meaning that the angle difference between the rotor and the grid increases. Now, if this load angle is between 0º and 90º the operation is stable because the atraction force between the magnetic poles of the rotor and stator is strong enough to drag the rotor along and hold it in place. However, if you keep increasing governor power the load angle will eventually surpass 90º. In this situation the operation is unstable because the magnetic poles are so far away from eachother that the atraction force is so weak that the stator is unable to drag the rotor with it so it happends what is called "pole slip", meaning that the machine loses synchronization with the grid and the generator starts to speed up to very high speeds.
Thank you @adriansolis126
When syncing a generator lets say the line and unit are in phase and the frequency is the same. In regards to the unit compared to the line how far out can the voltage be when syncing? Great Video.
5% voltage difference. It is sais that if its above that there can be damage to the rotor
Thanks for the explanation. I would like to know if power will also be fed to the grid, if frequencies are 100% synced but generator voltage is raised above grid voltage?
what will happen if the voltage values are different?
isn't it if the phase is the same, then whatever the difference in the voltage value won't be a problem?
Thank you sir, for the detail explanation. How could I download the software?
,thank you very much.
bro thank u 🙏
Thank you for the tutorial, it is really helpful. I have two questions. Why is the current zero if there is power output? When we are connecting generator to the grid, how do we take into account resistance of the grid?
Thanks in advance.
Hi, good observation on the 0 current. Just like the voltage where we have to select which phases to measure between before it shows voltage, we also have to select a phase to measure its current. I did not select a phase to monitor in this simulation, so it shows 0 amps by default. But there is amperage on each of the 3 phases which results in power delivered.
@@RyanTangney how can I access the full course lectures and exercises? I am willing pay for the content
sir when you say we need to match our generator's parameter with that of the grid what does it mean? And if there's already a grid why do power plants generate electricity and how do they send it back to the grid?
The grid voltage may vary a bit. MIne roams between 37,500 and 38200v. Your generator will have to be able to match that as well as the frequency, usually 60HZ. Outside of the power company specs, they will require you unit to trip. To send power back you would syn to the grid and stay connected. Any power you make above your own load would go backwards through the meter to push into the grid. This takes a special bi-directional meter as well.
thank you sir for putting this great video and its material together. i am interested learning generator synchronization, would you please tell me any education institute that offers it in Ontario.
I don't live anywhere near your continent, but I recognize his simulator as Kongsberg MC90-V. My suggestion is that you search for schools/universities which are educating marine engineers (engine officers).
At least in Europe "normal" electricians don't learn much about this, and only do so if they study to become some sort of master electrician (more simple, yet quite similar to an electrical engineer)
If you search for MC90-V or M22 there are a lot of tutorials out there.
How to measure generator power when they are perfectly in sync with the grid? I mean how to measure "the pull" If they have same position
Reactive power can be determined by the difference in voltage level between generator and grid. Active power can be determined by the phase shift between generator voltage and grid voltage.
Sir I wanted to clarify something. In the case of steam power plant, when the governor demands an increase in power, the generators respond by opening the control valve to increase steam input. Yet how does the turbine and generator speed does not increase by this higher steam input?
Governor controls speed not power. An increase in load (which will try to slow the generator) will require a higher steam pressure/flow to keep the Governor speed the same.
My GUESS is this has to do more with balancing net torque of the generator
When the generator is NOT synchronized to the grid, the Raise/Lower governor switch controls the speed of the turbine and generator. As soon as you match the speed to the grid in voltage and frequency, and the synchroscope shows that the sine waves match, you close the breaker and lock into the grid. Any further action on the governor ''Raise'' switch starts opening the poppet valves in the steam chest which adds load to the generator. The generator is locked to the grid like meshed gears so the speed will not increase.
The governors on the big base loaded turbine generators can influence the frequency of the grid but for the most part, the grid is usually so large that the addition of another generator has only a minuscule effect on frequency (speed). When you have a small grid system, the problem becomes a bit more complex to maintain frequency and has to do with the droop settings of the governors. You don't want a 600 KW diesel generator taking all of the load while the 2 Megawatt unit is only partially loaded. Each governor's droop settings can be tailored to prevent that.
Can the generator synchronised while the synchronoscope turn to slow direction (CCW)
Yes, it could happened in manual sync mode, done by operator. But be aware that operator immediately need to increase the load of synced generator, manually by increasing of the frequency/revs. In other case, the generator will take grid power and act as electromotor, with triggered generator reverse power protection. Luckily🙂
which is the synchronization simulator?
Hi how are you voltage and frequency, phase angle synchronising settings percentage how much?
You might want to clarify your question a bit? I’m not sure I understand the question itself.
@@marcelastacey890how much phase angle setting in the power generator?
@@marcelastacey890 87 G protection setting
Where can i download the simulation
thank you
Your system is actually for a ship not for power grid. The idea is same though.
The argument for setting the frequency to be slightly faster than the grid's frequency doesn't quite make sense to me. That argument seems more like one for setting the phase to be slightly ahead of the grid phase. Two sinusoidal waves that are even slightly different in frequency will eventually go 180° out of phase, creating a beat pattern.
my (very uninformed) guess would be that it is generally better to dump the excess power from the grid while slowing down instead of pulling power from the grid to speed up
Its better to have it go faster and then go slower when latched because if you are going slower than tha grid then the grid needs to inject power into your system to normlaize to its frecuency. You dont want to inject power into your grid. Normally theres relayprotections for reverse power but its not always the case.
Its easier to slow down the rotor by a bit (having more Hz and then attaching ) than injecting power to make the rotor go at the same speed.
If you are going slower than the grid, you can still sync, but as soon as you do, the grid will speed up your generator to catch up to grid speed and thus becomes a "motor" running off the grid and is a tad unstable. The power runs to the generator instead of to the grid and those units with a reverse power trip will open the breaker. This power trip in is place because if your generator looses power to the turbine and the breaker is still closed, it is a very large motor and will not stop even if you trip the turbine and shut off the steam. Trust me, I'm still cleaning up pieces from one that did exactly that.
@@billk364😮😅
Oo
Lovely simulation very informative, but sooo slow...
Konsberg simulator 😂😂
"When they operate at exactly the same frequency there is never an opportunity for their relative positions to ever change" - please tell this to the Honda engineers who designed the transmission in their 125 cc motorcycle I have. It sometimes jams when shifting gears precisely due to this reason. People, I recommend, don't buy Honda. I think their engineers are incompetent. Their motorbike is unreliable.
@ Working in Nunavut with jayjay explains woodward 2301