Hybrid switchgear

HYpact performs well in highly polluted environments and is an excellent choice in regions prone to seismic activity. Its compact design with a low center of gravity is ideal for withstanding seismic accelerations, as confirmed by shake table tests and finite element simulations. HYpact customers also benefit from long maintenance-free intervals thanks to reduced exposure to environmental influences and fewer bushings and moving contacts.

Why compact switchgear?

While looking for new solutions for power stations, power grid managers take actions to reduce the space requirements of devices and reduce their costs. GE, as a leader in SF₆ and air-insulated device technologies, offers an innovative compact switchgear: HYpact.

HYpact is a series of compact switchboards compliant with the IEC 62271-205 standard, containing circuit breakers, disconnectors and earthing switches. They can also be used to install current and voltage transformers and cable heads. The modular structure of the switchboard allows a wide selection of hardware configurations.

HYpact offers more than just space savings. There are also important economic benefits that must be taken into account: the reduced installation space requirement is achieved by combining all switching and disconnection functions in one device, thus reducing the costs of construction works. The device is also easy to transport and install, which helps reduce construction costs to a minimum.

By completely enclosing the elements in SF₆ insulation, maintenance becomes simpler and required at longer intervals compared to switchboards and other structures.
The closed design also increases operational reliability and safety in very demanding environmental conditions.

HYpact switchgear is particularly useful in highly polluted environments and extreme climatic conditions.

The modules of the HYpact switchgear produced by GE have all the advantages of the most modern switchboards: easy operation and maintenance, high reliability – and at the same time lower cost.

GE has been manufacturing air-insulated high-voltage switchgear for over 100 years. Over 120,000 devices manufactured by us are installed and used around the world.

We invest large amounts of money in research and development, thanks to which users of our products can benefit from the latest technologies and innovations.

Components

HYpact is a hybrid compact switchgear containing the following components:

• switches;
• disconnectors;
• earthing switches;
• transformers;
• other elements.

This device has been designed to meet the future needs of power grids.

Switch

The basic element of each HYpact switchgear is a single-phase closed dead tank. The monolithic cast aluminum housing requires a minimum number of seals, which ensures minimal gas leakage.
The bi-directional extinguishing chamber, also used in life tank and dead tank types, requires at least 65% less energy compared to traditional thermal self-blast switches, which significantly reduces the mechanical stress all elements of the HYpact switchgear are tested. The circuit breakers are controlled three-pole (combined) or single-pole.

Protected control cables

The phase-to-phase ties and the ties between the driving mechanisms and the switchgear may, if necessary, be completely enclosed for protection against environmental influences or for reasons of safety.

Culverts

The bushings can be supplied in porcelain or composite materials. The current leakage path has been designed for use in highly polluted environments.

Disconnector/earthing switches

HYpact switchboards can be equipped with various disconnectors and earthing switches made using gas-insulated technology. Gas insulation ensures protection of the contacts against environmental influences such as precipitation or sediment, contamination and icing, and the compact and closed design ensures that there is no need to adjust the contacts due to aging or lack of synchronization of short-circuit currents.

It is recommended to select a system with a combination of disconnector and earthing switch, in which the circuit breaker completes the earthing operation. The electrical load on the earthing switch (sometimes referred to as induced currents) is transferred to the much stronger circuit breaker, freeing the earthing switch from stresses that cause accelerated wear and damage and reducing maintenance requirements. The grounding principle is referred to as integral grounding and is common his not used in medium voltage technology, and now increasingly also in high voltage devices.

The three positions of the switching device are as follows: closed disconnector with open earthing switch, open disconnector with open earthing switch, and open disconnector with closed earthing switch. The disconnector and earthing switches are internally mechanically dependent on each other.

In situations where the station design and maintenance requirements do not allow for integrated earthing, a direct disconnect/earthing switch is used. In this arrangement, the earthing switch operates independently of the circuit breaker. Induced currents can be combined according to IEC 62271-102, Annex C, class B.

If necessary, the disconnector included in the integrated disconnector/earthing switch can be reinforced by the use of opal contacts, which allows the commutation of bus transfer currents that occur in large air-insulated stations (1600 A -100 V according to IEC 62271-102, annex B, class B [for large air-insulated busbars]).

As an additional option, short-circuit-resistant earthing switches (so-called quick earthing switch) are provided, which can be connected to live phase lines.

Current transformer

Epoxy resin insulated current transformers (with or without metal casings) are placed next to disconnectors/earthing switches in such a way that they do not require additional space. If located under a bushing, in most situations they can be slid over the bushing so that if the current transformer needs to be replaced, there is no need to work on gas-filled components.

Each current transformer can consist of up to seven cores. Since the number of cores depends on the current transformer’s ratio, number of taps, accuracy and power, current transformers are always selected for specific requirements.

The outputs of the current transformers are connected to specially designed terminal strips located in the central box for connecting measurement transformers or in the central control cabinet.

Voltage transformers

Inductive voltage transformers can be integrated. Such gas-insulated voltage transformers are equipped with gas barriers creating separate gas zones. Capacitive voltage sensors are also available.

Cable heads and surge arresters

Integrated cable heads are optionally available for several header types from their major manufacturers. Air-insulated surge arresters can be mounted on steel extension stands.

Central control

The switchgear control functions in each bay are integrated with the drive mechanisms or provided as a separate central control cabinet. The field is controlled using conventional relays and contactors, although alternatively programmable logic controllers and control electronics are also available. If bay control is integrated into the substation’s protection and control scheme, switchgear control at bay level can be avoided.

Optionally, the HYpact switchgear can be extended with an intelligent circuit breaker monitoring system (CBWatch).

Drive mechanism

The switches have a spring drive mechanism from GE FK 3-1 series devices. This mechanism uses the most reliable spiral compression springs installed in over one hundred thousand “life tank” and “dead tank” circuit breakers, gas-insulated switchboards and compact switchboards around the world.

The disconnector/earthing switches are controlled by a three-position drive mechanism with an electric motor, which also enables emergency manual operation.

The actuators of the circuit breaker and disconnector/earthing switches are mounted on steel supports and are therefore not only easy to adjust before shipment to the customer, but also conveniently accessible for inspection or emergency operation.

Type tests

The IEC standard for compact switchboards, IEC 62271-205 2008, in addition to carrying out type testing for each individual component, also requires the presentation of the characteristics of the device as a whole. Since the complete HYpact switchgear consists of a circuit breaker, disconnector, earthing switch and current transformer, it is subjected to extensive type testing, which includes, among others: power tests, insulation tests, mechanical and environmental tests.

Supplementary devices and functions, e.g. cable terminations or voltage transformers, are tested in accordance with the individual standards that apply to them, and also as components of the HYpact switchgear, to demonstrate that the interactions between the components and the HYpact switchgear do not constitute a limitation for their individual ratings or those of the device as a whole.

Research Testing of HYpact switchboards is carried out in accredited and certified testing laboratories.

Quality

We want to satisfy our customers by making improvements in all the processes we perform, including quality, costs and order fulfillment times. This applies to projects and administrative procedures throughout the entire business process, from submitting an offer to the final delivery of finished products, systems and services.

The ISO 9001-certified quality management system and the ISO 140001 environmental management system, as well as the OHSAS 18001-certified occupational health and safety systems are used throughout the entire development and manufacturing process of our high-voltage equipment and ensure the achievement of the highest quality standards of all our products and services.