DPY-1 Frequency and Voltage Stability Control Device

Introduction

Under abnormal system conditions, active power shortage and reactive power shortage may be so great that frequency and voltage drop severely , which in extreme cases can lead to frequency/voltage collapse . Under-frequency/under-voltage load shedding control devices measure power network frequency and voltage in real-time and once they drop to the pre-defined values will automatically conduct load shedding to restore system frequency and voltage. The DPY-1 frequency and voltage emergency control device is such kind of equipment that forms the third defense line for the secure and stable operation of power systems.

Type UFV-2A microcomputer based frequency and voltage emergency control device is mainly applied to centralized frequency/voltage emergency control at a substation due to its relatively large number of load shedding steps (5 steps) and its number of controllable load lines (20 lines). By comparison, DPY-1 is suitable to the control of 2 or 3 lines and in particular to the updating of traditional integrated circuit based frequency relays.

Features

  • DPY-1 is a compact frequency/voltage emergency control device that inherits all the mature techniques of UFV-2 serial products.
  • High measurement accuracy, reliability and dependability. Easy to maintain.
  • Can have 3 frequency/voltage settings and a three-step output by 'or' logic to control 3 lines.
  • Can have df/dt and du/dt settings. When frequency or voltage descends quickly enough, DPY-1 can automatically speed up the second and then the third step load shedding.
  • A friendly MMI with information operation data display.
  • Event recording, system fault process recording and operating parameters recording.
  • Capability of communication with other devices (RS-485) by IEC60870-5-103 protocol.
  • Reliable multi-lockout function to prevent malfunction.
  • Can be easily used for over-frequency/over-voltage generator tripping by changing software.

Engineering Application

DPY-1 has been widely used in substations and power plants.