1. Overview of solid state switch SSTS
Power quality problems, such as voltage swell, voltage sag and momentary interruptions, tend to bring about severe consequences and great economic loss to medium and large sized enterprises including, metallurgy, semiconductor manufacturing, hospitals and banks, etc. For example, they may lead to such problems as equipment shutdown, interruption of work flow, equipment damage and so on. For this reason, multiple power supplies are installed so that electric equipment with sensitive load can be swiftly shifted to other backup power supplies when there is something wrong with the main power supply. Therefore, the solid state switch can effectively enhance reliability of power supply and protect the sensitive electrical equipment.
Due to the limitations of physical structure and working mode, traditional spare power automatic switching tends to have the following disadvantages.
1) Low switch speed over 1s, which is unable to deal with important and sensitive load.
2)Short service life
3) Line breaking of voltage transformer and malfunction of spare power automatic switching.
4)Spare power automatic switching is prone to failure of operation and error locking.
Rongxin has independently developed its own medium, low voltage solid state switch SSTS which is below 35kV. The solid state switch is able to solve the problems existent in traditional mechanical switches and completely replace current spare power automatic switching devices. That is because it has greatly increased the switch speed and service life, which ensure that the sensitive load is free from abnormal power supply. In this way, the solid state switch is capable of ensuring normal operation of equipment, extending life time of equipment, increasing working efficiency, and thus infectively brings down the economical loss caused by power quality problems.
The solid state transfer switch SSTS is suitable for circuit with duplicate supply. When there is sudden interruption with the main power supply or any other abnormalities, it can automatically shift important load to back-up power sources, which ensures reliable power supply and protects sensitive electrical equipment.
Compared with products like DVR and UPS, Rongxin solid state switch has the merits of simple structure and high performance cost ratio. Besides, it is free of extra energy storing device and maintenance.
2. Field of application
Rongxin solid state switch SSTS can be applied in petrochemical industry, metallurgy industry, semiconductor manufacturing industry and hospitals, etc.
The Rongxin SSTS serial products are the best solutions to problems encountered in the aforementioned industries and other industries which have high demand for duplicate supply.
3. Featured functions of the solid state switch
1) Zero delay
2) Users can conduct the following setting.
a) Users can select preferred power supply.
b) Overvoltage and undervoltage threshold value can be adjusted.
c) Users can set the phase jump threshold value.
d) Switching can be prevented when something goes wrong with the load of the power system.
3) The solid state switch SSTS is enabled to monitor field apparatus through communication with the fieldbus or network by transmitting various operating parameters and working status of field equipment to the host computer or the remote control center, and by receiving data and orders from the host computer in return.
4) Human computer interaction is achieved by keyboard and liquid crystal display. You can input the parameters and function setups into controllers by keyboards, and then the controllers work according to the input information, displaying the operating parameters and working modes.
4. Technical features of the solid state switch SSTS
1) Swift switching, with the switching time within 5ms.
2) The With a high-capacitance high speed switch, which functions to cut off any short circuit current between 20-50kA within 12ms when there is ground fault of the load.
3) Integrated design of relaying and switch.
4) Single phase working mode.
5) Telemonitoring and remote control.
6) Both manual and automatic switching
7) 485 communication
8) Fault waveform recording
9) Man machine interface
10) Free of maintenance
5. Technical parameters
|Low voltage||Medium voltage||High voltage|
|Rated current can be adjusted to customers’ needs.|
|Voltage drop of steady state operation||Approximately 0 (<0.1%)|
|Turn off current||20-50kA|
|Switching time||MBB（closing before opening）mode <5ms,BBM（opening before closing）mode <12ms|
|Recovery time||Approximately 0, suitable for power system with high speed reclosure and multiple faults.|
|Cooling method||Natural cooling|
|Note||SSTS products of 35kV/ >1000Aare custom-tailored.|