Four insulation monitoring device circuit Solutions

Insulation monitoring device circuit solutions are essential for ensuring electrical safety by detecting insulation faults in ungrounded (IT) systems. The insulation monitoring device connects the live conductor and the earth and superimposes a measuring voltage Um. In the event of an insulation fault, the insulation fault RF closes the measuring circuit between the system and the earth, generating a measuring current that is proportional to the insulation fault. This measuring current generates a corresponding voltage drop at the measuring resistor Rm, which the electronics evaluate. If this voltage drop exceeds a certain value corresponding to a certain insulation resistance below, a signal is output

Different circuit designs cater to various applications, such as industrial power systems, energy storage systems, photovoltaic systems, medical environments, and transportation networks. This article presents four common insulation monitoring device circuit solutions.

Insulation monitoring device circuit solution for DC power supply

Application: DC panels such as power plants and substations, UPS power supply systems

The DC panel is connected to an AC 380V power supply, and the battery module is charged normally. When the AC380V power supply fails, the DC bus is powered by a backup battery. The insulation monitor can monitor the insulation of the DC bus and branches. When insulation damage or single-phase grounding occurs at any position in the DC system, the instrument sends an alarm signal to prompt the staff to troubleshoot the fault.

Blue Jay ZJJ Series DC Insulation Monitoring Device

DC insulation monitoring applications continue to emerge as more renewable energy and microgrid projects are implemented. DC insulation monitoring devices (IMD) such as the ZJJ series can provide a versatile and accurate solution for a variety of DC panels.

Insulation monitoring device circuit solution for DC charging pile

Application: DC charging pile

The following figure shows a dual-gun 120kW DC charging pile. The insulation monitor measures voltage, resistance and current by the controller. When the charging pile is used, when the A gun or B gun is used alone, the controller controls the corresponding IMD1 or IMD2 insulation monitor to perform insulation monitoring first; when the two guns are used at the same time, the controller controls the IMD1 insulation monitor to perform insulation monitoring first.

Blue Jay JY Series DC Insulation Monitoring Device

Monitor the insulation resistance value of the positive and negative poles of the 100~1000Vd.c. DC floating system to the ground.
Resistance measurement range 0KΩ～10MΩ.
Suitable for EV charging stations, espcially Dual ev charger.

Insulation monitoring device circuit solution for Energy storage system

Application: Energy storage system

As shown in the figure below, multiple insulation monitors are set up in the energy storage system, but only one insulation monitor is allowed to work in the same system at the same time, so a control module is required for control. A time-sharing control strategy is adopted, and a communication trigger method is adopted to ensure that only one insulation monitor is working at the same time.

Blue Jay BIM-CH1 Series DC Insulation Monitoring Device

It is avaible for AC systems and DC system.
multi-functional LCD display
Automatic self-test
Selectable N/C or N/O relay operation

Insulation monitoring device circuit solution for Photovoltaic system

Application: Photovoltaic system

As shown in the figure below, in the photovoltaic system, the photovoltaic components generate electricity and merge into the grid through the inverter. The inverter has its own isolation transformer, and the front end of each junction box is divided into an independent system. For independent ungrounded DC systems, insulation monitors should be installed to detect the insulation of the DC bus and branches to the ground. When insulation damage or single-pole grounding occurs, the instrument can promptly alarm and prompt the staff to inspect and troubleshoot the circuit to prevent the expansion of the fault and cause a short circuit.