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DDS-02F Smart Detector for Earth Faults

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Product Description:
1. Grounding line selection
Such detector can achieve the single-phase grounding line selection of the 3 kV - 66 kV isolated neutral system or the neutral grounding system of resistance and arc suppression coils. Its operation mode is free from the system operation mode and ground overcurrent resistance.
2. Display
It has the data displayed in Chinese, including real-time clock (RTC), detector operation state, system configuration parameters, busbar or line sequence numbers of earth or resonance faults, and time of faults.
3. Setting
Its Chinese menu is helpful for users to set or change line identifiers and RTC, and enable or disable any line selected.
4. Fault memory
It can retrieve the event logs of 84 earth faults, including busbar voltage, line selection result, and current and directions of different lines.
5. Online self-check of the detector
This detector can realize online self-check during normal operation to detect any fault, send a timely alarm and display the fault type.
Technological Advantages:
Compared with products of other domestic manufacturers, this system features:
1. The high-speed digital signal processor (DSP) chip is used as its core arithmetic and control unit. Such chip is manufactured with the static CMOS integrated circuit processing technique. There is an advanced modified Harvard architecture in it. The program memory and data storage unit have separate busbars. A multistage pipelined architecture is also available. With high processing speed, 50ns instruction cycle and multiply-accumulate instructions in its instruction set, such chip is very suitable for applications such as fast Fourier transform and harmonic analysis. Compared with 80C196 single chip microcomputer (SCM), it features high integration level, reliability and arithmetic speed (40 times the arithmetic speed of 80C196).
2. Such detector can operate with a KD-XH arc suppression system. Based on the electric characteristics of lines before and after arc suppression coils are used for compensation, it can rapidly and correctly select a grounding line according to the comprehensive data on break variables of zero sequence voltage and current, and the power direction. Even if such arc suppression coils exit or there is no such coil, it can also operate independently and rapidly and correctly select a grounding line according to the relative value of the zero sequence current and the power direction.
3. With a relative current comparator, this detector features flexible and convenient operation, as well as excellent capabilities of error correction, identification and interference suppression, without current setting.
4. The application of multiple 14-bit A/D multiplexed conversion chips ensures the high sampling frequency, rate, and calculation accuracy and results in the simultaneous sampling of busbar voltage and zero sequence current of the outgoing line. The number of current and voltage channels is respectively 38 (36) and 2 (4).
5. Such detector shows optimal hardware design. Its CPU system has a structure with the busbar on the motherboard. The detector communicates with any external electrical device via the optoelectronic isolator to effectively prevent external interference. With the advanced surface mounted technology (SMT) and excellent interference immunity, its CPU can achieve fast self-recovery in case of an unstable mains voltage or strong out-of-control interference. Such system features simple debugging and convenient maintenance.
6. The DC/AC power supply is available to protect it from any impact of the power supply.
7. This detector is complete with a large LCP and Chinese menu. All information on various operations, actions and faults is displayed in Chinese. Its HMI is user-friendly and easy to operate.
8. For variations of the zero sequence current in the automatic tracking system, there is no need to adjust or set the amplification factor. Thus, such detector is suitable for any field system with a primary zero sequence current between 0.5 A - 200 A. Specifically, it will have no dead zone in case of low primary ground current; and it will be unsaturated in case of high primary ground current.
9. Such detector features self-check, fault alarm, self-debugging, simple debugging and minimum maintenance.
10. It provides the alarm contact output for system grounding, remote communication contact output for encoding of line selection results, as well as serial communication interfaces (SCI) for optional RS422 or RS485. It can communicate with the remote terminal unit (RTU) or the substation automation system.
11. This product can operate with a KD-XH intelligent quick arc suppression system to achieve quick arc suppression for single-phase grounding in the low resistance grounding system and thus avoid any secondary transient earth fault. It also provides accurate line selection for the permanent grounding system.
12. This detector can store the information on line selection related to 84 earth faults with power-off protection to facilitate subsequent accident analysis.


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