Maxwell’s CONDIS® HV laboratory capacitors can be used as a key component in many applications, including as coupling capacitors for PD measurement, HV dividers for 50Hz voltage measurement, HV RC dividers for impulse voltage measurement, capacitive loads for series resonance installation, capacitive loads for DC installation, coupling capacitors for on-site PD measurement and coupling capacitors for generator circuit breakers.
Maxwell applies CONDOR (CDOR), the company’s latest technological development using aluminium foil capacitors with polypropylene-paper mixed dielectric, impregnated with synthetic oil, to its laboratory capacitors. Within our HV capacitors are over 100 flat windings connected in series. For optimal performance and longevity these elements must be identical, as any variations in one element will place added load on that element, and eventually cause it — and consequently the entire unit — to fail.
Maxwell is the only supplier of HV components in the world to completely automate its winding and assembly process, and thus has the unique ability to manufacture the elements within each unit to be identical. Also, as a result of this fully automated process, the company is the only manufacturer of HV capacitors to perform a quality check on each individual element as it is wound, in addition to testing the fully assembled final product.
The key element of Maxwell’s proprietary CDOR technology is the automated stacking and series connection of the flat windings through welded connections between the individual windings. This allows the suppression of aluminium connections and manual soldering external to the windings, a design still used today as standard technology by competitors. Maxwell applies this cost-intensive technology for the other product families, called CDCT and CDHT.
Fully automated winding and assembly line launched
In order to keep pace with the increasing market demand for HV capacitors and to maintain our market share of more than 60%, Maxwell recently put in operation the fourth so-called BOBDOR line, a new fully automated winding and assembly line with in-line quality controls.
In addition to the additional winding and assembly line Maxwell invested heavily in new processes and manufacturing equipment for drying, tightness test and impregnation. All these investments combined result in a drastic reduction in throughput time.
Lower weight, shorter lead-time, higher quality and reliability, less variation of the electrical performance, high temperature stability, and small size of active parts, resulting in lower capacitor cost as well as superior integration into the designs of the customer, are among the guaranteed advantages of CDOR technology.
Testing of HV capacitors
As part of our quality process, all CONDIS capacitors are individually tested in routine testing for several electrical performance parameters such as capacitance, tan delta, partial discharges and voltage levels. The capacitance measurement ensures no winding element has a breakdown. The partial discharge measurement ensures the capacitor has no defect that potentially could destroy the capacitor later during operation. The different voltage tests eliminate the risk of failure during the first period of service. All tests are performed according to IEC and ANSI standards.