A switchgear is a combination of devices designed to control, regulate, meter and protect electric generation, transmission and distribution equipment, and electric motor control systems. Siemens also nicely defines from the power generation point of view: “a switchgear is the equipment used in substations to control the distribution of power in high, medium and low-voltage networks.” However, today switchgears are being used even in industrial works & projects, domestic and commercial buildings. Nowadays, switchgear is the common term used to mean a circuit breaker or a switch disconnector or an isolator.
Depending on the voltage of the power line for which they are designed, the equipment are called high, medium or low voltage switchgears.
Fig. 1: A switch disconnector from Siemens targeted to protect PV and wind turbine systems…
Also, there are other types of classifications based on their constructions, e.g., Gas Insulated Switchgear (GIS) system, Air Insulated Switchgear (AIS) system, Oil Insulated Switchgear (OIS) system and so on. Yet another type of classification in their naming is based on the phases of the power system for which they are designed, e.g., 1-phase switchgear or 3-phase switchgear.
Besides stopping flow of current in a circuit manually, as very ordinary switches do, technically advanced switchgears automatically do the thing whenever there is an over current in the circuit or any other abnormal situation arises. Thus, it protects the valuable machinery, gadgets, equipment, circuitry or even human lives. Whether it is a domestic environment or a commercial establishment or an industrial set up, nowadays use of switchgears are prevalent everywhere.
Fig. 2: Eaton’s arc-resistant low voltage (LV)switchgear…
As purpose of this small article is to look at a few of the recent developments in the switchgear segment and gauge the overall market potential, let us now focus on those areas. Contextually, globally many innovations are happening in this field; however, as everything cannot be included in this small article, I am focusing just on a few of them…
A newly launched technology
Power management company Eaton has recently introduced a Low Voltage (LV) switchgear technology designed to extend type 2B arc-resistant ratings with the instrument and breaker secondary door open. According to Eaton, this is the industry’s first LV switchgear of this type.
The company informs that providing centralised control and protection for low-voltage power distribution equipment, the new switchgear is engineered to improve uptime for data centre, oil and gas, mining, utility and other mission critical industrial applications.
Bisrat Girma, Product Manager, Eaton, informs, “With an innovational two-part design, Eaton’s latest switchgear helps protect personnel around the perimeter of the switchgear from dangerous arcing faults.”
As per the manufacturer, the new switchgear design allows access to the control switch and indicator lights – located on the breaker’s secondary doors – without opening the main breaker door. This design has been made available for both front and rear access arc-resistant low voltage switchgears to help customers minimise the footprint of electrical distribution equipment while maintaining high safety standards.
The innovational two-part design also allows the circuit breaker door to remain closed while accessing control wire, and retains the C37.20.7 arc-resistant rating during routine maintenance to simplify access to circuit breaker secondary terminals and reduce unplanned downtime.
An installation using great skill
Alstom has recently installed three HYpact-modules in Gänserndorf substation, located in Lower Austria and owned by Netz Niederösterreich. The HYpact-modules are an extension of the existing substation and were connected to the grid in February. This is the first installation of HYpact switchgear in Austria.
The need: As a result of the increasing wind energy infeed from the wine growing area in the east of Lower Austria, the extension of Gänserndorf substation became necessary to ensure grid security in the future. However, there the availability of space was very limited.
The specialty of the equipment: The HYpact module is Alstom’s latest innovative and compact hybrid switchgear. Its flexible design allows for a large variety of layout configurations, and is suitable for both cost and space savings.
Due to the limited space in Gänserndorf substation, Netz Niederösterreich decided to use the hybrid technology HYpact, which is suitable for outdoor use. The compact HYpact allows a space saving of over 50%, compared to the conventional air insulated substation. In addition, all switching units are integrated in the module, and due to the full encapsulation of the SF6 gas, the maintenance cost during the lifetime is significantly decreased.
In the words of Carsten Kramer, Area Sales Manager of ALSTOM Grid, Kassel, “The compact switchgear HYpact constitutes the first delivery of its kind for the Austrian market, taking into account country-specific requirements such as the legal regulations for pressure vessels. At the same time, it is the world’s first HYpact switchgear delivered with a make-proof earthing switch that allows direct switching to an impending short circuit.”
The hybrid switchgear was developed, produced and tested in the Alstom Grid competence centre for live tank circuit breakers and compact switchgear assemblies at the Kassel site.
Fig. 4: SENSeOR’s Energy S1 system enables real-time load management and prevention of avoidable problems through remote surveillance…
An innovative diagnostic method
Switchgears protect the devices connected to the power system but how to protect the switchgear’s health? Well, there are companies to address this area too. SENSeOR from France has recently launched its new optimised wireless batteryless system for real-time temperature monitoring of electrical equipment. According to the company, this is the first and only multi-point system approved by an accredited laboratory for worldwide license-free use in Medium Voltage switchgears.
The company also informs that ‘remote continuous monitoring of critical equipment of the power grid’ is one of the key solutions helping utilities, OEMs and panel builders coping with the new challenges that they are facing. Contextually, most of their challenges are now coming from increased power demand and renewable energies integration. SENSeOR’s Energy S1 system enables real-time load management and preventive problem avoidance through remote surveillance of the most critical points inside Medium Voltage AIS switchgears, with flexible configuration (multi- ystems, multi-sensors: up to 18 sensors per system).
As per the manufacturer, some other important features of Energy S1 are:
- The temperature sensors, based on SAW (Surface Acoustic Wave) resonators, are totally passive
- They are maintenance-free
- Their form-factor and design are optimised for robust and safe operation under high voltage and current
- The installation of the system is quick and easy, even in retrofit, and doesn’t impact the thermal, dielectric and mechanical properties of the switchgear
- Equipment integrity is preserved
- The sensors have passed successfully all dielectric tests as per IEC 62271 norm, they survive short-circuit and lightning, and operate up to 545kV and 5kA
Besides those features, Energy S1 include some innovative, patented interrogation methods; and its hardware provide a robust, reliable, self-tested, self-healing communication in the metallic cavity of the switchgear cabinet. For load management, six sensors can be easily fitted on the circuit breaker arms.
Global market trend
According to the recent report published by the Taiyou Research, the global market for switchgears is anticipated to do well in the coming times as demand is likely to be driven by medium and high voltage types of switchgears. Revenues in the switchgears market are closely tied with the demand for transformers, therefore, any increase in demand for transformers will lead to a rise in demand for switchgears and vice versa.
The report also states that the global Gas Insulated Switchgear (GIS) market is expected to show impressive growth in the future. The market for switchgears will continue to evolve globally, being led mainly by escalating demand for renewable sources of energy, growth in construction and industrial sectors – especially in developing countries, and government efforts to upgrade and modernise electricity transmission and distribution systems. Although environmental regulations offer scope for expansion, volatile oil prices, rising raw material prices, and restricted flow of investments in the electricity sector act as immediate stumbling blocks.
The Taiyou Research team further predicts that rising investment in alternative sources of energy is expected to contribute to the growth of Medium Voltage (MV) and Low Voltage (LV) switchgears used for switching and general protection. Moreover, this application area will also trigger demand for Miniature Circuit Breakers (MCBs) and Moulded Case Circuit Breakers (MCCBs).
They feel, “Against a backdrop of tough economic climate, corporate success will critically hinge upon the ability to research and develop new innovative products at competitive prices and validate new applications for existing products to distinguish themselves from that of competitors. Several technological developments such as arc-resistant technology and magnetic actuation have been undertaken by various Original Equipment Manufacturers (OEMs) focusing on enhancing the reliability and efficiency of switchgear equipment.
Growth in switchgears will also be sustained by government directives to replace older redundant systems to achieve operational safety, and security in industrial establishments.
Although global economic crisis and falling oil price have created a great uncertainty in the global economy, the focus of the power industry is shifting towards renewable energy everywhere. Most of the renewable installations, whether small or large, are getting connected to the grid, where installation of switchgears is absolutely essential. Thus, demand for switchgears will definitely go high in the coming years.