ECOTAP VPD - The new compact class for distribution transformers
In 2012, Maschinenfabrik Reinhausen (MR) launched the world's first tap-changer solution for voltage regulation distribution transformers ready for mass production. The new ECOTAP VPD combines the know-how that MR has accumulated over the decades in vacuum on-load tap-changers with the experience in voltage regulation distribution transformers gained through working with transformer manufacturers and operators. The ECOTAP VPD provides superior vacuum technology at a price that makes use of voltage regulation distribution transformers even more attractive and further expands the range of application.
Technologically superior – economically convincing
The compact dimensions of the ECOTAP VPD on-load tap-changer permit installation in virtually any power-rating class of distribution transformer without any major changes to the footprint. What's more, the electro-mechanical operating principle of the proven MR vacuum technology with 500,000 maintenance-free tap-change operations ensures stable and reliable operation for decades without the need to service the primary equipment. The direct drive with up to 20 tap-change operations per minute enables quick responses to changing grid conditions. Nine tap-changer positions with a mid-position which the operator is free to choose ensure a large regulating range with fine steps between the tap changes. Thanks to its IP54 degree of protection, the ECOTAP VPD can be used outdoors and can be used in selected synthetic and natural esters. Operation in applications with stringent environmental compatibility and thermal demand requirements is therefore also possible.
The compact controller, another new feature, certainly lives up to its name as it is just 10 cm wide and 35 cm tall. Using an adapter, it can be installed on the busbar to the width of one single fuse panel to save space. All parameters can be set with ease on the controller, so no laptop is needed.
Wide range of possible applications in public grids
Voltage regulation distribution transformers are real all-rounders – they maintain a constant voltage in public, industrial, and private distribution grids by compensating for fluctuations in the medium and, if necessary, high-voltage levels and responding dynamically to changes in the feed-in and demand. Selective use, focusing on one specific task in the low-voltage grid, is now a very common application. Nowadays, voltage regulation distribution transformers are also used to optimize the cost-effectiveness of the grid topology and to decouple voltage at medium- and low-voltage levels.
A voltage regulation distribution transformer with the new ECOTAP VPD solves the crux of the problem – compliance with the voltage band through dynamic adaptation. The low voltage is decoupled from the medium and the voltage band can be re-distributed and therefore used more effectively. The grid's ability to absorb power can be increased by up to a factor of 4.
In most cases, expensive grid reinforcement can be completely avoided and grid equipment put to more economical use. In this regard, reference is generally made to selective use, where individual secondary substations are equipped with a voltage regulation distribution transformer.
When voltage regulation distribution transformers are used on a feeder basis or in all parts of the grid, the focus is on the medium-voltage grid. Feeder-based use is always recommended if there is a risk of the voltage band limits being infringed in a larger interconnected area at the medium-voltage level starting at a certain distance from the primary substation. This may be the case at the end of feeders or due to large fluctuating or constant feed-in and/or consumers. Decoupling the underlying low-voltage grids from the voltage of the affected medium-voltage feeder or ring permits much greater changes in voltage band than would otherwise be possible. This results in greater potential for feed-in and demand to be integrated into the medium-voltage grid and the underlying low-voltage grids.
If voltage regulation distribution transformers are used in all parts of the grid, all secondary substations not located in the direct vicinity of the primary substation are fitted with new technology. This is a good idea if there is a risk of the voltage band being infringed in the entire medium-voltage grid. The desired voltage value on the HV/MV transformer can also be reduced in order to allow an even higher voltage rise in the medium-voltage grid. In this way, the voltage regulation distribution transformers can prevent or postpone major grid reinforcement measures in the medium-voltage grid.
Optimization of the grid topology
An efficient distribution grid has as little equipment as possible. Voltage regulation distribution transformers with ECOTAP VPD increase the efficiency of grid sections and reduce the total number of secondary substations, thereby cutting investment and maintenance costs. The number of secondary substations needed for a grid area is determined firstly by the maximum possible distance between the secondary substation and grid connection points from a voltage standpoint and secondly by the maximum demand to be covered and/or the maximum feed-in to be transported.
Voltage regulation distribution transformers dynamically adapt the voltage and thereby permit a larger electrical supply radius around each secondary substation. In this way, even consumers or feed-ins a long distance from the secondary substation can be connected. The grid operator can combine two secondary substations or can be spared from having to build a new secondary substation. This results in savings for rent, maintenance and servicing of the stations, as well as for investments in replacement or new equipment. The only requirement is that one transformer is configured such that its performance is sufficient for the enlarged grid area.
Stabilizing industrial processes in volatile grids
Industrial processes are extremely dependent on a stable voltage, which isn't always provided. In grids with limited generator power, long distances or volatile consumers and producers, the supplying medium voltage may be subjected to large fluctuations in voltage. As a result, production processes may be interrupted, motors may not start or control systems may crash. This can cause serious damage, especially in sensitive industrial processes. In addition to direct impacts on processes, frequent changes in voltage may also have a negative impact on the life of equipment.
A voltage regulation distribution transformer with ECOTAP VPD in the industrial distribution grid ensures that consumers have a stable supply of voltage regardless of the volatility of the medium voltage. Due to the large regulating range, even large fluctuations in the medium voltage can be reliably regulated for many years and without any maintenance. The compact dimensions help to keep costs down because the voltage regulation distribution transformer can be installed in place of the conventional one.
Energy costs can also be significantly reduced by optimized voltage. Energy consumption for conventional loads is affected by factors such as the voltage with which the equipment is supplied. If equipment is supplied with a higher voltage than needed, the equipment consumes more energy than needed.
Using a voltage regulation distribution transformer with ECOTAP VPD in the industrial distribution grid allows equipment to be supplied with a voltage actively optimized for it. This reduces energy consumption without limiting the equipment's function. The voltage regulation distributions transformer's controller balances the voltage between what is available and what is ideal for consumption. Before the voltage falls to a level where equipment operation is at risk, the voltage regulation distribution transformer intervenes and restores the voltage to a level which is ideal for consumption. This enables energy costs to be reduced by up to fifteen percent.
Dispersed generation plants – economically complying with grid connection conditions
For integration into the grid, dispersed generation plants based on renewable energies (photovoltaics, wind, biogas) must meet the relevant requirements of the grid operator in the form of grid codes. The provision of reactive power, which depends on grid voltage, is particularly criti-cal. In cases where the requirements placed on providing reactive power are particularly demand-ing, making the required reactive power available can often only be accomplished either by oversizing the inverters or by requiring the generation plant to operate such that it reduces the amount of active power fed into the grid to suit the situation. Neither approach is particularly attractive; the former because it increases the system costs of the generation plant and the latter because it restricts the system's output. The operator's profits suffer in both cases.
The voltage decoupling made possible by the voltage regulation transformer means there is no need to oversize the inverters or reduce the amount of active power fed to the grid, which ultimately makes the generation plant more cost-effective. Alternatively, the additional space obtained by using the voltage regulation transformer can be used to operate an existing generation plant with a higher power rating. Voltage regulation transformers can be integrated in all dispersed generation plants. Typical examples include photovoltaic parks and wind turbines.
In the case of wind turbines, voltage regulation transformers can be combined with all drive-train concepts, such as asynchronous generators or full-scale inverters. The voltage regulation transformer can either run on its own or be integrated in the generation unit's regulation system. Given the very limited amount of space available, particularly in wind turbines, the compact dimensions of the ECOTAP VPD are as important as the large regulating range and the maintenance-free operation in alternative insulating fluids.
ECOTAP VPD – more power, more value
The new ECOTAP VPD is the world's most compact on-load tap-changer for distribution transformers offering the largest range of services. It achieves maximum cost-effectiveness for the entire transformer/on-load tap-changer system, is maintenance-free, already satisfies the requirements of the EU Ecodesign Directive for 2021, and can be operated with synthetic and natural esters as insulating fluids. The ECOTAP VPD is perfectly tailored to the processes of transformer manufacturers and is highly versatile – be it in public distribution grids, industrial applications or dispersed generation units.