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1.
Introduction
¡¡¡¡As the development of power electronics
(PE), high-power PE equipment such as HVDC, FACTS and DFACTS controller
are widely used in electricity and industry applications. The PE
devices at work will produce great amount of heat, which has a major
impact on the full utilization of high power semiconductors, hence
a suitable cooling system is necessary. However the continuous increase
of current handling capability of power electronic devices originates
further problems for thermal control and performance of the cooling
system. The high thermal efficiency (up to 250% performances increases)
of the water cooling technology assures low cost, high reliability
level and a compact design of the power converter, and makes it
the optimal option for many applications, e.g. for high voltage
and high power equipment, such as HVDC and TCSC applications, only
liquid cooling is applicable.
¡¡¡¡The water-cooling system is normally
furnished with interconnecting piping, ductwork, circulating pumps,
blowers, heaters, make-up reservoirs, heat exchangers, filters,
water treatment plant, instrumentation, automatic controls, alarms,
control power systems, and other necessary equipment. The purpose
of such a system is to remove the considerable amount of heat generated
by the PE devices and other components, and to restrict the semiconductor
junction temperature to a safe steady-state value. The liquid coolant
is distributed within the valve via insulating hose links which
have high reliability terminations, it takes the heat and then transfer
it trough the closed recirculating system to the ambient air, which
take place in a water-to-air or water-to-water heat exchanger. Because
water is used in cooling high voltage electrical equipment, in order
to keep the electric insulation capability, a treatment loop to
maintain the high purity (high resistivity) of the water in the
closed system should be provided. A few percent of the main water
flow pass through the water treatment circuit with deoxygenizer
and ion exchanger vessels, it keeps the content of oxygen low, and
captures any charged particles and ions that may contaminate the
system to maintain the resistivity of the water above 1M/cm at 20oC.
¡¡¡¡The PLC based control equipment comprises
a programmable control, protective and a monitoring system. Although
the water-cooling system is usually remotely controlled from a central
control room, it can also be operated locally via PLC. The graphic
language software provides a high quality user friendly operation.
The programmable control system enables well defined transfer functions,
easily adjustable parameters, and tolerates partial or modified
system operation. The Man Machine Interfaces (MMI) utilizes the
latest technologies to provide the possible environment for the
operator, as regards security, efficiency and ergonomics.
2. Specification
number |
Name |
Specification |
1 |
heat dissipating capacity |
100-1500kW |
2 |
Rating coolant flow (main loop) |
20-80T/h |
3 |
Rating coolant flow (treatment loop) |
10-200 l/min |
4 |
Resistivity of coolant (main loop) |
>2MW*cm |
5 |
Resistivity of coolant (treatment loop) |
>5MW*cm |
6 |
Liquid inlet temperature |
30~40oC |
7 |
Liquid outlet temperature |
40~50oC |
8 |
Maximum liquid pressure |
6 bar |
9 |
pH |
7 |
3. Application
¡´ Static Var compensator (SVC)
¡´ Static Synchronous Compensator ( STATCOM)
¡´ Thyristor Controlled Series Capacitor (TCSC)
¡´ High Voltage DC Transmission ( HVDC)
4. List of water-cooling projects
¡´ Sunten Electric corporation 10Mvar 10kV SVC
ICR (Intelligent Closed-Recirculating ) pure-water cooling system
¡´ Tangshan Iron & Steel Ltd. 20MVar 35kV SVC
ICR pure-water cooling system
¡´ Laiwu Steel Mill 50MVar 35kV SVC ICR pure-water
cooling system
¡´ National Engineering Research Center for T&D,
Power Electronics laboratory
ICR pure-water cooling system
¡´ Dalian steel Mill 20MVar 35kV SVC ICR pure-water
cooling system ( 2 sets)
¡´ Shandong Molong Special Steel Mill 50MVar 35kV
SVC ICR pure-water cooling system
¡´ Jilin Tonghua Iron & Steel Ltd. 20MVar 35kV
SVC ICR pure-water cooling system
¡´ Shandong Quanxin 20MVar 35kV SVC ICR pure-water
cooling system ( 2 sets)
¡´ Ningbo Steel Mill 20MVar 35kV SVC ICR pure-water
cooling system
¡´ Jinan Lilute Steel Mill 20MVar 35kV SVC ICR
pure-water cooling system
¡´ State Grid Corporation, Lingbao 220kV Back-to-Back
HVDC Project, ICR pure-water cooling system
¡´ Shanghai Municipal Electric Power Company 50Mvar
STATCOM ICR pure-water cooling system
¡´ Bicheng power transmission line(Gansu Province)
120Mvar 220kV TCSC ICR pure-water cooling system
¡´ Anshan Substation 120Mvar 35kV SVC ICR pure-water
cooling system
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