Development Of CZ0-40A DC Permanent Magnet Non-arc Contactor

Arc will be initiated during the process of pulling and breaking in traditional DC contactor and the coil of contactor has to be charged with electricity to keep it on pull-in status. So disadvantages like large consumption of power in coil, noise production when works, and strong arc on the main contact exists in traditional contactor which means a great waste of electric energy, pollution to the surrounding environment, and greatly reduction of the lifetime of contactor too.By the research of transformation including permanent and non-arc technology was applied with original CZ0-40A DC contactor, DC permanent magnet non-arc contactor was developed. NdFe permanent magnet material combining with and high power electronic device were adopted in the electromagnetic system of contactor. The contactor can be maintained in pull-in status with the magnetic flow generated by permanent magnet and the coil only needed to be charged when the moment it was pulled in, which brings with the correspondence of solution with power consumption in coil fundamentally. The problem of release when brake and voltage loss of power supply in permant magnet contactor was solved with special measures, which contributes to the features of strong electromagnetic pull-in, energy conservation by permanent magnet self-maintain, and noiseless. Meanwhile bidirectional triode thyristor was assembled in parallel on the original contactor and special electrical control device with isolation of strong and weak current function was equiped to control the contacts and the sequence of operation. By open the bidirectional triode thyristor first when connect the circuit and close it lag behind the seperation of contacts when disconnect the circuit, the breaking of circuit could be achieved by the cut-off of SCR with no-arc-off in contactor. Moreover, the weakness of high loss in breakover and poor overload capacity was conquerred with the host of circuit conduction by mechanical contact.NdFe permanent magnet material, power electronic devices and mechanical contacts was first time applied on CZ0-40A DC permanent magnet non-arc contactor based on traditional contactor with the advantage of conservation in power and material, noiseless and no-arc-off. And the project is simple and easy to apply with good performance of reliability. Only coil has to be replaced and arcing chamber to be changed into bidirectional triode thyristor together with its control device while with no need of change with the overall dimension and external characteristics of original contactor. So the market prospect of this technology is vast.