One-stop high voltage power quality solutions
Even in modern electrical systems, power generation enterprises cannot completely control their power quality. Some power quality variation is caused by the power consumer, or physical and environmental factors. However, voltage sag and short supply interruption can severely impact power quality, an extremely common problem that needs urgent solutions quite often. Sinopak high voltage static var generators are designed to solve issues with power quality in high-voltage lines. A set of STATCOM on the high-voltage line can effectively solve the problems of voltage deviation, harmonics, voltage fluctuation, and flicker. This effectively increases the voltage quality, minimizes line losses, and ensures the operation of the system is economical.
On the basis of the experience in recent years, Sinopak TSVG successfully realized the high voltage active harmonic filtering function from 3kv to 35kv, which can completely eliminate harmonics from 2 to 13. Compared with the traditional SVC, SVG adopts active elements. As the TSVG, it can not only be used in reactive compensation equipment, but also used in high voltage active harmonic filtering equipment.
（1）Full-enclosing designed for power units
The control panels of power units adopt a totally-enclosed structure design to ensure the operational stability of SVG under wet, windy, and dusty environments.The controlling and driving board of power units is made of silicone, which has good potting properties. The silicone maintains its elasticity and stability in the temperature range of 55 °C to 180 °C. It has outstanding thermal conductivity and insulation properties, making sure that the SVG can operate stably in salt spray conditions.
（2）Fully enclosing designed for control cabinet
The controller can also adopt the totally-enclosed structure design to prevent external dust or fumes from entering the controller, ensuring reliability in dusty or wet conditions.
Since heat dissipation is needed after the controller is closed, to make sure that the inner temperature is in a reasonable range, a blower is set into the top and the bottom parts of the control cabinet to realize the internal air circulation to lower the temperature.
The whole control system units are comprehensively screened, which has lower power consumption and high reliability, which improves the stability of the entire system. The simulating thermal process performed by the FlOWTHREM controls the inner temperature at an average of 67 °C at an outside temperature of 45 °C to satisfy the parts temperature in the service environment.
（3）Power module detector
SVG is mainly made up of a group of power modules. To help clients find module faults in time, Sinopak designed a power module detector which can find module faults quickly and easily.
What’s more, Sinopak installs the GPS modules in the SVG control room to help clients analyze issues.
The SVG power electronic equipment has certain demands for operating conditions. When used outdoors, the SVG can only be installed in containers. There are still some differences between the containers and houses in the protective performance such as constant temperature, warmth, and heat insulation, making the SVG more easily affected by the external environment. Therefore, installing SVG indoors is more beneficial to long-term working stability.
In the meantime, the initial investment cost of the air-cooling SVG system is lower than the water-cooling system. Therefore, if the SVG is operated in a relatively stable indoor condition, without considering bad conditions such as high salt spray, high humidity, and windy and dusty environments, the air-cooling SVG will be a more cost-effective choice.
2. Suitable for water-cooling SVG indoors
（Closed-loop water cooling system, no need water supply at site）
Sinopak takes full account of security and reliability when designing water-cooling SVGs. Thus, to avoid the short circuit problems caused by water leakage in the cases of various failure conditions, the circuit connection and water connection of the modules are separated.
The water-cooling line is designed as a layered symmetrical structure to reach the current sharing control, and the non-current sharing mobility is below 5%.
The water among modules adopts a paralleled method, and are independent of one another, which prevents problems of overheating of the back module caused by the water line in series, allowing the water line to radiate heat evenly.
3. Suitable for air-cooling SVG outdoors(-45℃~45℃)
For air-cooling SVG outdoors, the biggest challenge is to accommodate for any adverse conditions. For example, coastal salty and foggy conditions, humid environments, and dusty environments.
Sinopak designed a totally-enclosed power unit controlling drive board for the containerized air-cooling SVG, which is sealed by an infusion of silicone material to protect it from salt-fog environments.
We use a variable speed system with real-time calculation of the required air volume of the equipment by detection of the module temperature, and adjust the air speed as needed, which can not only effectively prevent the sand and salt spray from entering the equipment, but also significantly reduce the fan power and the daily operating cost.
4. Suitable for water-cooling SVG outdoors
The water-cooling SVG outdoors unit features IP54, the power valve trays are all set in an enclosed space, and heat dissipation can be finished through a water-cooling system. The whole process will operate without interaction with the outside environment. More importantly, there is no need to clean dust periodically and change the filter screen, so the maintenance cost is lower.
More significantly, in tough conditions, the air-cooling SVG needs to use solutions of dehumidification or air conditioning to fill the gaps. Not only will the investment of the initial equipment increase, but also it needs to increase the floor space of the whole equipment, and the effect is not as good as water-cooling SVG .
Therefore, water-cooling SVG is a lower-cost and more stable choice than air-cooling SVG in sandy, ashy, high salt spray and high humidity environments.
1. Power Grids
The power consumption of power plants is an important component of energy consumption for power generation in power plants. How to improve economic benefits is the main problems that the power plants focus on.
There are many electrical equipment in power plants, such as air blowers, circulating water pumps, electric water pumps, crushers, air compressors, coal conveyors, and so on, most of which are induction-motor type loads. It will consume a lot of active power and reactive power when working, so that the natural power factor is low. In consideration of the need for reducing resource consumption, a variable speed system will be installed generally, which will produce a large amount of harmonic currents. The injection of harmonic currents will lead to complications of safe operation of the motors, transformers, transmission lines and other equipment in the system. SVGs can effectively solve this problem. It can compensate reactive power and eliminate some of the harmonics at the same time. When a fault occurs in a power system or the load suddenly increases, the SVG system can also dynamically provide voltage support to avoid large-scale blackouts caused by transient voltage breakdown.
2. Wind Farm
Wind power has developed fast in China. The characteristics of wind power are environmental friendliness and mature technologies. However, because of the uncertainty operation characteristics of the wind resources, it will cause the instability of the output power of the wind generating set, which can cause a series of problems such as voltage fluctuation and flicker from grid interconnection of wind farms.
These problems can all be solved by a dynamic reactive compensation system, which can not only satisfy the requirements of power factor, voltage fluctuation and flicker of wind farm integration system, but also reduce the effect of the system disturbance on the fan. If on the basis of using SVG, the capacitors and reactors can be used together to form an integrative compensation system, the cost can be further reduced and the performance will be better.
The mobility and scalability of SVG also make the entire reactive power compensation system extend simultaneously according to the construction of the wind farm.
3. Electric Traction
Large-scale transportation systems utilizing electric traction such as high-speed rail and subways feature a single-phase nonlinear load. While running, they may generate harmonic currents, causing voltage waveform distortion, three-phase voltage asymmetry, and voltage fluctuations, which may lead to equipment flaws.
The SVG is available for compensating the locomotive traction power supply system, and increase the power factor dynamically, suppress the voltage fluctuation, flicker, and impact which are caused by the reactive power, and eliminate the harmonics produced by the electric locomotive while running in the meantime.
The SVG system produced by Sinopak has been widely used in electric power, railways, urban underground and railway traffic.
4. Metallurgical Industry
The metallurgical industry usually uses a lot of high-power devices, for example, arc furnaces used to melt steel. However, most of these power devices are non-linear loads. When connected to the power grid, there will be a series of negative impact on it, such as generating complex higher harmonics, serious voltage flicker, and decrease of the power factor, which will not only imperil the safety of electricity, but also reduce the efficiency of production.
The only method to thoroughly solve the above problem is to install an SVG which has rapid response speed to provide reactive current to the power devices quickly, meanwhile stabilizing the grid voltage and increasing electrical active power output, which will not only enhance productivities greatly, but also minimizes the influences of flicker, which can eliminate higher harmonics, and increases power factors by suppling capacitive reactive power to the system.
5. Heavy Industrial Loads (such as rolling mills, hoists, etc)
The auxiliary power system of heavy industry such as rolling mill and winches is made up of higher power facilities such as frequency converters and motors, which will inevitably leads to some problems such as lower power factor, frequently fluctuate of the voltage, and abundant harmonic current, which causes a great deal of distribution losses.
The driving device which is installed inside the load can generate dangerous higher harmonics which makes major distortions of supply voltage, it will not only reduce the power quality, but also influence the normal operation of the power grid and electrical devices. In that case, the electrical devices are difficult to work normally and reduces production efficiency directly.
The SVG system can help industries which own heavy industrial loads stabilize voltage, increase power factor, and lower energy consumption, thereby bringing dramatic economic benefits to major industrial companies such as metallurgical industry, petrochemical, mining, and seaports.