ZDFVR Intelligent Flexible Voltage Regulating Device

The intelligent voltage quality optimization device is designed to address voltage quality issues in the three-phase distribution network such as grid voltage fluctuation and low grid power factor.

The entire device is serially connected to the outlet of the distribution transformer on the system side via a coupling transformer, featuring fully automatic control. It real-timely detects grid voltage data, compares it with the set output voltage, and flexibly controls the voltage to be compensated through the converter part with bidirectional regulation and flexible output voltage setting within a wide adjustment range. The inverted output voltage is coupled to the system side through the coupling transformer and superimposed with the system voltage to achieve the purpose of voltage compensation; that is, only the difference part needs to be compensated to minimize the compensation power. The device has two operating modes: main circuit operation and bypass operation. When the device detects normal grid voltage, it automatically switches to bypass operation, the converter stops running and enters the standby state. At this time, the grid voltage is directly supplied to the subsequent load through the coupling transformer, minimizing the overall operating loss of the device. The basic principle of the device is shown in Figure 4.1. The two operating modes of the device can be freely switched with adaptive control judgment, providing a safe and stable operating environment for the subsequent sensitive loads.

The main features of the intelligent voltage quality optimization device are as follows:

High system efficiency and fast response speed: Three-phase voltage continuous compensation, response time ≤ 5ms;

High reliability: Multi-level protection, simple circuit, high reliability and low maintenance work;

Modular design of power part: Easy maintenance, effectively reducing the workload of operation and maintenance personnel, lowering operation and maintenance costs and improving work efficiency;

Independent design: The device adopts outdoor single-pole independent installation for convenient on-site construction;

Multi-functional design: It can reduce operation and maintenance workload (no need to adjust the transformer again), solve high and low voltage quality problems, and realize reactive power compensation, etc.

(a) Grid voltage US (b) Compensated voltage uc(c) Load voltage uL

Figure 3.1 Schematic diagram of application and governance effect of the intelligent voltage quality optimization device

The main circuit topology of the device is shown in Figure 3.2, which mainly consists of a PWM rectifier side (ACDC module), a PWM inverter side (DCAC module), a coupling transformer, a bypass unit, a power distribution unit and other components.

Figure 3.2 Main circuit topology of the intelligent voltage quality optimization device

On-site Installation

3.1 Installation Materials

The intelligent voltage quality optimization device is installed in the low-voltage power supply and distribution line and shall be fixedly installed in strict accordance with the installation schematic diagram. The installation materials include the intelligent voltage quality optimization device, mounting bracket, hoop, fixing bolt, cable and other materials.

3.2 Mechanical Installation

The entire device is installed on a single pole. Professional personnel shall install the hoop at the specified height, then install the base, and check for loose or slipped bolts after installation; Use a crane to move the base of the entire device to the height of the bracket position, align the mounting holes on the outside of the device with those on the bracket, and insert bolts for fixation; Refer to the installation schematic diagram 4.1 for installation.

Figure 4.1 Mechanical Installation Schematic Diagram

(M16 screw, nut, flat and spring washer; Hoop; New power electronic voltage regulator; Base)

3.3 Electrical Installation

Open the side cabinet door of the entire device with the key attached to the cabinet, and the input and output marks can be clearly seen. Make wiring cables of appropriate length, crimp the two sides of the cables with wiring terminals, and check for falling off or loosening of the crimping;

Connect the A/B/C/N on the input side of the device to the outlet side of the transformer, connect the A/B/C on the output side to the subsequent line, short-circuit the grid N line with the device N line, and reliably ground the PE busbar; Fix the antenna of the communication module on the top of the cabinet to ensure reliable installation;

After the completion of electrical installation, check for loose or missing wiring. The electrical installation can be connected in accordance with the schematic diagram.

Figure 4.2 Electrical Installation Schematic Diagram of the Entire Device

(PE; Outlet; Inlet)

3.4 Installation Notes

Mechanical and electrical installation shall be operated by professional certified personnel;

After the entire device is installed, check the lines for abnormalities;

Construction personnel shall be equipped with safety helmets and safety ropes before operation;

Unauthorized personnel are prohibited from entering the construction site;

The entire construction process shall be monitored and recorded at the construction site.

4. Maintenance

The intelligent voltage quality optimization device is maintenance-free during on-site operation. On-site maintenance of the device can only be performed by after-sales personnel and is limited to the cleaning and inspection of the device and its components. All service and maintenance work shall be carried out by our company.

4.1 Daily Maintenance

The device shall be cleaned and inspected every six months or more frequently. Perform cleaning and inspection in the following steps:

1. Disconnect the incoming line circuit breaker at the front stage of the device;

2. Check for loose control connections;

3. Check the firmness of electrical and mechanical connections;

4. Check all wires for damage;

5. Check if the fan is working normally;

6. Check if there is dust accumulation at the air inlet and outlet;

7. Turn on the power after the inspection is completed