Do you really need that RP ?!

The horror that is happening now (and has been happening before) when obtaining Technical Conditions for connection, or already during their implementation, has pushed us to this publication.

Especially striking was the case when to connect 400 kW at 35 kV, the power distribution company demanded the consumer to install a transformer with RP in their networks, because that's what is written in the signed Technical Conditions))

Let's delve into this issue a bit.

It's no secret that the current state of electrical networks, especially after the damage caused by our "friendly neighbors," is far from ideal. And in this situation, distribution system operators (DSOs) often try to protect themselves from potential further complaints from subscribers regarding non-standard voltage levels. To do this, DSOs include a requirement in the Technical Conditions for connection regarding the installation of transformers with RP in the consumer's networks. Although neither existing regulatory and technical documentation nor common sense requires this.

At first glance, what could be wrong if there's a device in your internal networks that automatically regulates and maintains voltage?!

Let's first go over the technology:

Voltage regulation on power transformers can be of two types:

1. No-load tap changing ( NLTC )
2. On-load tap changing 

In the first case, the transformer needs to be disconnected from the network to switch, while in the second case, switching is done with the transformer running without disconnecting consumers.

Additionally, remote control of OLTC is usually provided, or even automatic operation mode.

However, the advantages of transformers with RP end here, and there are many significant drawbacks:

1. Such transformers are significantly more expensive than those with NLTC. The cost difference can amount to tens of thousands of dollars (depending on the parameters), and this doesn't even include control automation.
2. They reduce reliability since RP switches are one of the main causes of transformer failures.
3. They require regular inspection and qualified technical maintenance, which in turn increases operating costs.

Consumers often hope that transformers with RP are a panacea for voltage fluctuations in their networks. But it's worth remembering that this is not a stabilizer, and the RP switch has a limited number of switching cycles.

In our practice, when designing and implementing Automatic Voltage Regulation systems in DSO networks, operational staff often switch the automation to manual control in most cases, fearing that such operation will quickly wear out the switch and render the transformer inoperable.

Our friendly recommendation for businesses connecting to electrical networks or increasing their capacity:

❗️ Don't rush to sign the Technical Conditions issued to you! Carefully read each requirement.

❗️ Check whether these requirements correspond to your technological needs and the peculiarities of your facility.

❗️ Even better - involve qualified specialists who can advise on the correct technical and economically justified solutions. This will save you from unnecessary expenses and further problems during implementation and operation.