Solving Maintenance Issues for High-Voltage Photovoltaic (PV) Systems

During maintenance and inspection, different measuring instruments are used for different purposes to check photovoltaic panels. For example, the voltage measurement function of a digital multimeter or clamp meter can be used to measure the open-circuit voltage of a PV string. If the measured value is significantly lower than the standard value, it may indicate an open circuit in the string or a defect in a PV module.

As system voltages continue to increase, relevant safety standards have been revised. Measurements on grid-connected photovoltaic power generation equipment are now classified as Measurement Category III. The P2010 DC High Voltage Probe, which supports CAT III 2000V measurements, can be used together with the CM4375-50 AC/DC Clamp Meter to measure increasingly high-voltage PV systems more safely.

Reasons for the Increasing Voltage of Photovoltaic (PV) Systems

Challenge 1: Reducing Energy Loss During Power Transmission

Upgrading a power generation system from 1000V to 1500V can improve power generation efficiency. When the current is high, energy losses during power transmission are also higher. Increasing the voltage while reducing the current helps reduce these energy losses. Therefore, PV systems are being upgraded to higher voltages in order to minimize losses and maximize the utilization of generated electrical energy.

Challenge 2: Revisions to Safety-Related Standards

The IEC 61010 international safety standard established by the International Electrotechnical Commission defines measurement categories to ensure that measuring instruments can be used safely, while protecting personnel from electric shock and preventing equipment damage. According to the international safety qualification standard for photovoltaic modules, IEC 61730-1, PV modules fall under overvoltage category CAT III, requiring measuring instruments capable of CAT III measurements.

Challenge 3: Low Efficiency Due to a Large Number of Measurement Points

When inspecting large-scale photovoltaic facilities, inspectors must check thousands of PV modules one by one. If the measuring instruments they carry are also heavy, the workload is further increased. Therefore, maintenance and inspection of PV systems must not only be safe, but also require compact, portable, and efficient measuring instruments.

Solution

CAT III 2000V Test Probe Used with a Clamp Meter

The HIOKI P2010 DC High Voltage Probe combines a compact design with a high level of safety. Without interrupting the power system, it enables safe measurements on megawatt-class photovoltaic power generation equipment. When used together with a HIOKI clamp meter or digital multimeter, it supports high-voltage measurements up to CAT III 2000V.

The P2010 DC High Voltage Probe is compact and lightweight and can be operated with one hand, overcoming the bulky size and poor portability of conventional products. In addition, its safety design is capable of withstanding 2000V DC, helping prevent electric shock and equipment damage. The P2010 also features a long probe tip that can reach metal terminals located deep inside junction boxes, thereby improving work efficiency.

The CM4375-50 AC/DC Clamp Meter features slim jaws that can easily access cables in confined spaces and automatically detects AC or DC. It can measure currents up to 1000A and AC voltages up to 1000V. When used with the P2010 DC High Voltage Probe, it can safely measure DC voltages up to CAT III 2000V.