As an integrated and modular power supply equipment, the high-voltage container unit is widely used in industrial production, emergency power supply, power supply in remote areas and other scenarios due to its advantages of convenient installation, strong protection and wide adaptability. Among them, the 10.5kV model is a typical configuration in current engineering applications, and it can also flexibly adapt to different voltage level requirements such as 6.3kV, 6kV and 11kV. This article will elaborate on the complete electrical configuration of the high-voltage container unit, including the core system, auxiliary facilities, safety guarantees and implementation standards, providing comprehensive technical reference for the selection, installation and operation and maintenance of the unit.
The electrical configuration of the high-voltage container unit is based on the rated parameters, which defines the applicable scope and operation benchmark of the unit. The rated voltage of the unit is 10.5kV (line voltage), adopting a three-phase 50Hz power supply mode, the common rated power covers 800kW～3000kW, and the rated speed is stably maintained at 1500rpm to ensure the continuity and stability of power supply. The generator adopts a three-phase Y-connection mode, and the neutral point is grounded through an NGR resistor, which effectively limits the ground fault current and ensures system safety; the insulation class reaches Class H, and the temperature rise is assessed according to Class F, which can adapt to the operation requirements under complex working conditions; in terms of protection class, the generator is IP23, and the main body of the container is IP54/IP55, which can effectively resist the intrusion of external dust, rainwater and other impurities, and is suitable for outdoor and harsh environment installation and use.
The main generator system is the core of the unit's power supply, and its configuration directly determines the power supply quality and operation reliability. The core component of this system is a brushless synchronous generator, which can be selected as a single-bearing or double-bearing type according to requirements. The brand is preferably internationally renowned brands such as Stamford, Leroy Somer and Meccalte, or domestic high-voltage series products with equivalent performance. The excitation method adopts PMG permanent magnet excitation combined with digital AVR. This configuration not only has excellent anti-distortion ability, but also can realize precise voltage regulation, among which the steady-state voltage regulation rate is ≤±0.25%, and the strong excitation capacity can reach 10s 300% overload, ensuring that the unit can still maintain voltage stability when the load fluctuates. At the same time, the generator voltage waveform distortion rate is ≤3% (no-load and half-load conditions), the cold insulation resistance (15–35℃) is ≥2MΩ, and the power frequency withstand voltage can bear 1min 42kV (to ground), which fully meets the insulation and withstand voltage requirements of high-voltage equipment. To further ensure system safety, the unit is equipped with a neutral point grounding cabinet (NGR), which contains grounding resistors, current transformers, ground fault protection devices, isolating switches, indicator lights and other components. Its main function is to limit the ground fault current, suppress overvoltage, and facilitate the selective tripping of the relay protection system to reduce the risk of fault expansion.
The high-voltage switch and power distribution system is a key link in the transmission and distribution of electrical energy of the unit, mainly including high-voltage switchgear, PT cabinet and parallel cabinet (configured when multiple units are paralleled). Among them, the high-voltage switchgear, as the generator outlet cabinet, has a vacuum circuit breaker (VCB) as its core component, with a rated voltage of 12kV and a breaking capacity of ≥25kA, which can reliably cut off the fault current and ensure system safety. The cabinet is equipped with measuring and protection class (5P20) CT/PT, among which the PT specification is 10.5kV/0.1kV, which is mainly used for voltage measurement, synchronization control and overvoltage/undervoltage protection; at the same time, it is equipped with a 10kV zinc oxide arrester to effectively protect the generator and main transformer from overvoltage impact. In addition, the switchgear also has short-circuit, overload and ground fault protection functions, supports manual and electric opening and closing operations, and is equipped with position indication and electrical interlocking devices to prevent misoperation. The PT cabinet is an optional configuration, whose main function is to provide voltage signals, synchronization signals, instrument power supply and protection voltage sources for the system, ensuring the normal operation of the control and protection system. When multiple units need to be paralleled, a parallel cabinet is required. The cabinet integrates automatic synchronization and manual synchronization devices, has frequency difference, voltage difference and phase angle difference interlocking functions, and can realize automatic reactive power and active power sharing between units, ensuring the stability and economy of parallel operation.
The control and protection system is the "brain" for the safe and efficient operation of the unit, covering three modules: unit controller, high-voltage relay protection and local/remote monitoring. The unit controller preferably selects well-known brands such as Deepsea DSE7320 and ComAp or domestic products with equivalent performance. It has automatic start/stop and AMF (automatic transfer when mains power fails) functions, and can real-time monitor key operating parameters such as water temperature, oil pressure, speed, voltage, current, frequency and power. At the same time, it integrates multiple protection functions such as overvoltage/undervoltage, overfrequency/underfrequency, overcurrent, short circuit, overspeed, high water temperature and low oil pressure. It can automatically record fault information and historical events, and support RS485/Ethernet remote communication, providing convenience for operation and maintenance management. The high-voltage relay protection adopts a microcomputer protection device, which is equipped with complete protection functions, including generator differential protection, overcurrent/instantaneous trip protection, ground fault protection (NGR side zero-sequence CT), overvoltage/undervoltage protection, overfrequency/underfrequency protection and reverse power protection (when grid-connected). It can quickly respond to faults, cut off the fault circuit in time, and minimize the risk of equipment damage. In terms of monitoring, a combination of local and remote methods is adopted. Locally, the high-voltage control panel and low-voltage control panel are centrally arranged on one side of the container, facilitating on-site operation and monitoring; remotely, it supports MODBUS TCP/4G/5G communication protocols, and can be connected to the SCADA system or cloud platform to realize real-time remote monitoring of the unit's operation status, parameter adjustment and fault early warning, improving operation and maintenance efficiency.
The low-voltage auxiliary electrical system provides guarantee for the normal operation of the unit, mainly including AC400V low-voltage power distribution cabinet and DC24V DC system. The low-voltage power distribution cabinet mainly supplies power to various auxiliary equipment, including anti-freezing and moisture-proof equipment such as water jacket heaters, space heaters and moisture removal heaters, environmental control and auxiliary electrical equipment such as container lighting, sockets, exhaust fans and electric shutters, as well as safety and control equipment such as chargers, control power supplies and fire/smoke detectors; the cabinet is equipped with MCCB, miniature circuit breakers, leakage protection devices, indicator lights, voltmeters/ammeters, etc., to ensure the safety and stability of auxiliary power supply. The DC24V DC system, as the emergency and control power supply of the unit, adopts 24V maintenance-free lead-acid or low-temperature storage batteries with a capacity of 150–200Ah, and is equipped with an intelligent floating/equalizing charger with an input voltage of AC400V, which can realize automatic charging and discharging management of the storage batteries; at the same time, it is equipped with a battery isolating switch (lockable), fuse and insulation monitoring device to ensure the reliability and safety of the DC system, and avoid the impact of DC power supply failure on the normal start-up and operation of the unit.
The excitation and AVR system is the core auxiliary system to ensure the stability of the generator voltage, working in coordination with the main generator system. The unit adopts PMG permanent magnet brushless excitation mode (standard configuration). Compared with the traditional excitation mode, it has the advantages of strong anti-distortion ability, reliable starting performance and convenient maintenance, and can adapt to the needs of different load conditions. As the control core of the excitation system, the digital automatic voltage regulator (AVR) can not only realize automatic voltage regulation to ensure the stability of the generator output voltage, but also support reactive power/power factor control and reactive power sharing during parallel operation, further improving the power supply quality and operation economy of the unit.
The cable, busbar and grounding system is the "blood vessel" of the electrical configuration, which directly affects the safety and reliability of electrical energy transmission. The high-voltage cable selects YJV22-8.7/10kV flame-retardant copper core cable, which is mainly used for electrical energy transmission between the generator, high-voltage cabinet and NGR cabinet, and has the characteristics of flame retardancy, temperature resistance and corrosion resistance; the low-voltage cable selects ZR-YJV 0.6/1kV specification, and the control cable selects ZR-KVV/KYJVP shielded cable, which has oil resistance, heat resistance and anti-interference ability, ensuring the stable transmission of control signals and low-voltage electrical energy. The high-voltage cabinet adopts copper busbar (TMY) with insulation heat shrinkage treatment to improve insulation performance and prevent short-circuit faults. In terms of the grounding system, the container shell must be reliably grounded (no less than 2 places), and all electrical equipment such as the generator neutral point, high-voltage cabinet, NGR cabinet and low-voltage cabinet are connected to a unified grounding grid. The grounding resistance is required to be ≤4Ω, which effectively releases the fault current and ensures the safety of equipment and personnel.
The safety and interlocking system is an important guarantee for the operation of the unit, which eliminates potential safety hazards through multiple protective measures. The high-voltage door interlocking device can realize the function of power-off or locking when the door is opened, preventing personnel from entering the high-voltage area by mistake and causing electric shock accidents; the electrical interlocking device can effectively prevent misoperations such as closing with ground and closing ground knife with electricity, ensuring equipment safety; the emergency stop device adopts a three-way control mode of on-machine, control panel and remote, which can quickly stop the machine in case of sudden faults, minimizing fault losses; at the same time, safety signs such as high-voltage danger, no closing, grounding signs and warning lights are posted on the container and electrical equipment to remind personnel to pay attention to safety.
To meet the personalized needs of different scenarios, the unit also provides a variety of optional configurations. If it is necessary to use a low-voltage unit for step-up power supply, a 400V→10.5kV box-type transformer can be configured; if it is necessary to realize automatic switching between mains power and the unit, an ATS/dual power switching device can be matched; if it is necessary to improve remote operation and maintenance capabilities, a remote monitoring box can be configured, integrating 4G/5G, GPS and cloud platform functions; to strengthen fire safety, a heptafluoropropane/aerosol fire protection system can be configured, matched with smoke and temperature detectors; for noise and thermal insulation needs, double-layer rock wool insulation, air intake and exhaust noise elimination and electric shutters can be adopted to reduce the unit's operating noise and adapt to low-temperature environments.
The electrical configuration of the high-voltage container unit strictly follows relevant national and international standards to ensure equipment quality and operation safety. Common implementation standards include GB/T 2820 "Reciprocating Internal Combustion Engine Driven Alternating Current Generating Sets", GB/T 1029 "Test Methods for Three-Phase Synchronous Machines", GB 50149 "Code for Construction and Acceptance of Busbar Installation in Electrical Installation Engineering", GB 50217 "Code for Design of Power Engineering Cables" and IEC 60034 "Rotating Electrical Machines". All configurations meet the standard requirements and can meet the power supply needs of various engineering scenarios.
Post time: May-15-2026
