The history of medium voltage switchgear

Medium voltage circuit breaker

In 1895, GE developed the first oil circuit breaker, and in 1915, GE installed the first metal armored medium voltage switchgear. In 1926, GE developed the world's first handcart type circuit breaker switchgear, and in 1928, GE also developed the first vertical lift oil circuit breaker switchgear in the United States. In 1962, GE developed the first vacuum circuit breaker. In 1966, GE developed a 34.5kV withdrawable circuit breaker switchgear...

Vertical lifting switchgear circuit breakers were later replaced by air circuit breakers and vacuum circuit breakers, but with the same structural form. Many manufacturers around the world have this product, ABB、 Siemens and others have circuit breaker products that are suitable for this switchgear renovation.

Later on, horizontal withdrawal appeared. GE developed the world's first 15kV, 2-layer layout, horizontal withdrawal vacuum circuit breaker switchgear PowerVac in 1976. The circuit breaker compartment highly integrates all measurement, control, protection and other functions.

Europeans do not like such highly integrated products, as they are not very convenient to operate. The upper layer is particularly high and the lower layer is particularly short, without a separate instrument room, so the floor standing design was born. It is easy to pull out and push, with a moderate height, and can be separated once and twice. The instrument room is easy to inspect and maintain.

In this way, the beautiful country continues to use double-layer circuit breaker switchgear (IEEE standard), while Europe and other regions use single-layer circuit breaker layout (IEC standard).

The Belledone produced by Schneider Electric in 1958 is a floor standing circuit breaker, and later in 1980, a 36kV Fluair air insulated switchgear was developed. These switch cabinets are still mainstream products in Southeast Asia and other places, sturdy and durable, and in line with the operating habits of local people such as height.

With the miniaturization and vacuumization of circuit breakers, as well as the need for more compact switchgear in primary systems, the mid mounted circuit breaker switchgear adopts wall mounted guide rails to reduce the impact of ground level, and can be easily repaired and maintained by transferring handcarts.

The lower part of the switchgear circuit breaker can be equipped with voltage transformers and other functional handcarts, reducing the number of switchgear.

The German production time of ABBZS1 switchgear (UniGearZS1) can be traced back to 1993. At that time, Xiamen ABB Switchgear Co., Ltd. imported UniGearZS1 switchgear technology from ABB Germany and began production in China.

Subsequently, Schneider mid mounted circuit breaker switchgear was born in 1996.

In the 1990s, foreign brands of switchgear entered China one after another, including ABB's VD4 and ZS1, 3AH, and 8BK20, which were introduced to China. Later, foreign brands such as Schneider MCSET, MVNEX, Evolis vacuum circuit breakers, Eaton W-VAC circuit breakers and switchgear, and Malaysia's Tiggo VH series with VK circuit breakers entered China.

The VS1 circuit breaker jointly developed by domestic companies such as Changzhou Senyuan (S stands for Senyuan) and the KYN28 switchgear were born, ushering in the era of mid mounted domestic medium voltage air insulated switchgear.

With the advancement of technology and the rise of solid-state switches, transformers, etc., medium voltage switchgear will also undergo a qualitative change. In the future, it should be highly integrated, and switchgear should have more system control and protection devices for circuits.