Sakshi Diman

Grid Synchronization and it’s unique Challenges in India

What is Grid Synchronization?

Synchronization is the process of matching the voltage and frequency of a generator or other source to a running network. An AC generator cannot deliver power to an electrical grid unless it is running at the same frequency as the network. If two segments of a grid are disconnected, they cannot exchange AC power again until they are brought back into exact synchronization.

A direct current (DC) generator can be connected to a power network by adjusting its open-circuit terminal voltage to match the network voltage, by either adjusting its speed or its field excitation. The exact engine speed is not critical. However, an AC generator must match both the amplitude and the timing of the network voltage, which requires both speed and excitation to be systematically controlled for synchronization.

In modern grids, synchronization of generators is carried out by automatic systems.

 

Problems in India?

In India, the need for a good grid synchronization is even more than countries like the US because of the following reasons –

  1. Varying voltage – The voltage in India is one of the most unstable in the world which is ranging from 110V to 270V. This variance adversely affects the inverter and can cause damage to its internal components.
  2. Frequency – Frequency variance(40-60Hz) is as extreme as voltage variance and can also affect the inverter performance adversely.
  3. Power Cuts  – In India the power cut problems are not new. The power cuts can vary from 2 to many times a day depending upon the area one is living and can again hinder the performance of the inverter.

 

Why is Grid Synchronization necessary is necessary and which scheme to choose?

Now, this is where Grid synchronization come into the picture. The purpose of synchronization is to monitor, access, enable, and automatically take the control action to prevent the abnormalities of voltage and frequency by the minimization of difference in voltage, frequency, and phase angle between the corresponding phases of the generator output and grid supply.

India has unstable grid. It keeps varying in different regions and states of India. The voltage varies from 110 to 270V(already stated),  because of that grid feed is affected by unstable voltage which directly affects the inverters.

A good synchronization scheme must:

  1. Proficiently detect the phase angle of the utility signal
  2. Track the phase and frequency variations smoothly
  3. Forcefully reject disturbances and harmonics.

These factors, together with the implementation simplicity and the cost are all important when examining the credibility of a synchronization scheme.

 

Six Reasons why Remote Monitoring Solution is essential for your roof top Solar Installations!

In the era of fast development, we are consuming a lot of energy in our homes. With the advent of Roof-top Solar Installations, now everyone has access to the generation of electricity. As the popular saying goes, what can be measured, can be managed. Homeowners often tend to ignore the importance of remote monitoring system when they Opt-in for Solar Installations. Monitoring is empowerment. This empowerment in electricity generation is known as Remote Monitoring System or RMS in short. So let us dive deep and see how we can utilize this power –

1) Tracking power system – Remote Monitoring System regularly monitors, collects and transmits the whole data related to the power produced by the Solar PV System. It displays the key performance data such as each system/equipment performance, each parameter like solar panel voltage(input voltage), solar panel current(input current), grid voltage(output voltage), grid current(output current).

2) Maintenance and Servicing – RMS gives you the power to have less to nill downtime. Downtime “refers to a period of time that a system fails to provide or perform its primary function”. What RMS does is predicts when your power system can break or have some malfunctioning or just start underperforming. It gives you a warning so that you can accordingly call the service department. The best part is that RMS is also available at remote locations that will let your system provider know when there is going to be a problem and they will call you for servicing. That right there is peace of mind guaranteed so you don’t have to worry about the breakdown, ever!

3) Predictive Forecasting – RMS lets you see how much energy will be produced in near future like in two days or a week. You can see the forecasting each and every day and can plan your usage accordingly.

4) Report Generation –  Remote Monitoring System can generate various types of mission-critical reports. You can even make customizable reports as you see fit. You can also make it from comprehensible to complicated with a lot of parameters in place.

5) Integrating Sensors – RMS can easily integrate external sensors such as a pyrometer, temperature sensors etc which helps you to analyze the performance of various different components. A must for any techie lover or anyone who wants to have deep down analysis.

6) Controlling the system remotely – Probably one of the best features of a Remote Monitoring system is that you can control the whole power system of your house or workplace just through an app. Through this app, you can switch ON or OFF any equipment remotely! Adding on, you can also be notified if you are using more than your average power consumption. Not only this but you can also get notifications on your mobile if any equipment is not performing according to the standards.

Why ThingsWiFi is the best choice for Remote Monitoring System

ThingsWiFi is a WiFi-based RMS system for Solar Grid Inverters and Solar Grid Interactive or Hybrid Inverters. It will keep on updating each pulse of your solar system promptly. Also, it helps you with the predictive maintenance of your system and the forecasting of the generation. It is a smart monitoring system that will provide you with –                                   

1) WiFi-based communication – Generally normal RMS use sim based communication that costs you an extra charge every month. But Things WiFi lets you use your home or office wifi for all the communications between you and the system, saving you from the extra bill and giving you a smooth service.

2) Integrate external sensors – With Things WiFi, you can easily integrate any and all sensors External Sensors are pyranometer, temperature sensors, wind meter, battery management systems etc and get all their reports and analysis.

3) Multi inverter compatibility – You will be able to integrate any type of inverter with ThingsWifi such as ThingsHifi, Delta, SMA, ABB etc. This gives you the power to choose over time any inverter that you like, without changing the whole system.

4) Dashboard availability – You don’t need to worry to get an extra device or a new operating system to see the dashboard of Things WiFi. Be it Web or mobile, Android or IOS, you can easily access the dashboard from the device you are already having.

Things WiFi makes it easy for you so that you can monitor different inverters connected to your system from a single platform. It allows you to connect and monitor up to 28 inverters at a time!

5) Analyzing Data – Analysing data becomes just so easy and fun with ThingsWiFi. Things WiFi gives you the complete freedom to choose different types of graphs with respect to different sensors, style, comprehensibility etc. 

Fig: Web Dash Board

Fig: Mobile Dash Board

7 Things to ensure before buying a solar inverter

So you have already decided to opt for the clean solar power system at your home or office. But before implementing the solar installation make sure that that you are going for the right solar inverter which is considered to be the heart of your solar power system. It is said so because a solar panel can convert the direct current into alternating current only with the help of an inverter. Not only this but a solar inverter reduces the user’s overall electricity consumption and the money spent on paying the monthly utility bill. So keeping up in mind its immense importance, we have aligned some important aspects to look for in a solar inverter.

 

1) Calculate your power requirements

Before buying a solar inverter you should know what are your power requirements. When there is a power cut determine what are the equipments that are necessary for you at such time. Then look for the power ratings of these equipments. For eg: you would want to use three ceiling fans(90W each), three tubelights(30W each), one CFL(15W), one laptop(70W) and one desktop(120W). Then your power requirement will be the sum of the watts of all the equipments i.e 565 W.

 

2) Determine VA rating of the inverter

Often VA rating and Watt rating are confused to be the same but they are actually not. Watt is the power drawn or supplied by an equipment. VA is the apparent power which is obtained by multiplying the Voltage and Current supplied by an equipment. The relation between VA and Watt is as follows –  Power rating of the inverter (VA) = Total power requirement (Watt)/Power Factor (PF) of the inverter.

Check the PF of the inverter, generally, it lies between 0.6 to 0.8.

So applying the above, you would need an inverter whose VA rating lies between 706 VA to 940 VA (Approx).

If the amount of VA rating is less than your power requirement then your inverter will get tripped because of overload and nobody wants that to happen at their hour of need.

 

3) Check the certifications of the inverter

Certifications ensure that your solar inverter is not only safe but also at par with the standards set by the leading solar power generating organizations. There are some standards that are mandatory to have in the solar inverter while other standards are used to verify the various power ratings as promised by the manufacturer. All in all make sure your inverter is certified for the respective standards. Typically Solar Inverters should comply to several of the IEC standards and a few required certifications are stated here.

  • IEC 62116- Anti-islanding
  • IEC 62109- Safety
  • IEC 61683- Efficiency
  • IEC 60068- Environmental
  • EN 61000- EMC
  • IEC 60529- Ingress Protection

 

4) Servicing and maintenance 

Generally, the lifespan of a good solar inverter is in many years, even when it is subjected to very harsh conditions. But to make sure that the inverter is working with its full efficiency, yearly servicing is required. This includes qualified technicians to check the proper connections between the cables and the removal of the worn out parts of the inverter.

Make sure that the company is always available for you when the time comes and always show support.

 

5) Support during Voltage variation  

There are times when there are sudden variations in voltage such as low grid voltage. So at those times, it is important for the inverter to maintain giving continuous power supply to the household/workplace. For a good solar inverter, the voltage variation support should range from 120V to 280V.

 

6) Load Surge Capacity

Most equipments like AC, washing machine and pumps need inrush currents that can range from 3 to 10 times their steady-state currents. For eg – A 1KVA inverter with 3x surge rating can smoothly handle an AC or a washing machine than a 2KVA inverter with 1x surge rating. So it is very important for the solar inverter to have the surge capacity to handle such kind of sudden loads that is necessary for starting above stated electrical equipments.

 

7) Protections

Apart from all the above features that a solar inverter must have, you should always go for the one that has protections like – short circuit protection, battery protection, IP protection(for eg- If you are placing your inverter outside, please make sure you have at least IP 54 rating,though IP65 is the best option) and earth leakage protection. With these savior features put all your worries to rest and enjoy the clean solar power energy at your home.