Multiple Choice Questions 51-100

51.When operating under conditions without shadow obstruction, with solar irradiance of( ) or above, and wind speed not exceeding( ), the temperature difference on the surface of the same photovoltaic module (the area directly above the cells) should be less than( ). Photovoltaic power plants with a capacity greater than 50 kWp should be equipped with infrared thermal imaging devices to detect temperature differences on the surface of photovoltaic modules.

(A) 400 W/m², 4 m/s, 20℃

(B) 400 W/m², 2 m/s, 20℃

(C) 500 W/m², 4 m/s, 20℃

(D) 500 W/m², 2 m/s, 20℃

Answer: D

52.The inverter input is( ), output is( )

(A) AC, AC (B) AC, DC

(C) DC, DC (D) DC, AC

Answer: D

53.The standard of the “Technical Specifications for Photovoltaic Power Plant Grid Connection” stipulates that the grid connection point of the photovoltaic power plant should be equipped with an online monitoring device for power quality of Class A that meets the requirements of( ) standards.

(A) GB/T14549

(B) GB/T24337

(C) IEC61000-4-30-2003

(D) GB/T15543

Answer: C

54.The communication between the monitoring system of the photovoltaic power station and the dispatch center should preferably use the( ) communication protocol.

(A) DL/T 634.510 4

(B) DL/T 634.510 1

(C) DL/T 719

(D) DL/T 667

Answer: A

55.After cutting a solar cell into two pieces, the voltage of each piece( ).

(A) increases (B) decreases (C) remains unchanged (D) uncertain

Answer: C

56.According to the “Technical Specifications for Photovoltaic Power Plant Access to Power Systems”, large photovoltaic power plants connected to( ) voltage levels should be equipped with synchronized phasor measurement units (PMUs).

(A) 220kV and above (B) 35kV and above

(C) 10kV and above (D) 110 kV and above

Answer: A

57.Based on the working temperature range, proton exchange membrane fuel cell power generation systems belong to( ) type fuel cells.

(A) ultra-low temperature (B) medium temperature

(C) high temperature (D) low temperature

Answer: D

58.The electrical device used to convert electrical energy into one or more forms suitable for grid use is( ).

(A) rectifier (B) filter (C) inverter (D) converter

Answer: D

59.The standard design working voltage of a battery is 12V, then the disconnection voltage of a fixed lead-acid battery when fully charged is 14.8~15.0V, and its recovery connection voltage value is generally( )

(A) 13.7 V (B) 14.6 V (C) 15 V (D) 12 V

Answer: A

60.Solar cells are generally made of semiconductor materials, among which the following is not a semiconductor material( )

(A) glass (B) gallium arsenide (C) germanium (D) silicon

Answer: A

61.The “Technical Specifications for Photovoltaic Power Plant Grid Connection” requires that when the photovoltaic power plant is designed for irreversible grid connection, when reverse current exceeds the rated output of( ), the photovoltaic power plant should stop supplying power to the grid within 0.5~2s.

(A) 2% (B) 3% (C) 1% (D) 5%

Answer: D

62.In a solar photovoltaic power generation system, if the power generated by the solar cell array is to be used for AC loads, the main device to achieve this function is( )

(A) voltage regulator (B) battery (C) diode (D) inverter

Answer: D

63.The energy generated by solar cells is stored in the battery in the form of( ).

(A) mechanical energy (B) electrical energy (C) thermal energy (D) chemical energy

Answer: D

64.Changing( ) can change the output voltage frequency of the inverter.

(A) carrier frequency (B) modulation wave frequency

(C) modulation wave amplitude (D) modulation ratio

Answer: B

65.In GIS fully enclosed combined electrical appliances, the pressure of SF6 gas is usually used in the range of( ).

(A) <0.2MPa

(B) 0.2～0.6MPa

(C) >0.6MPa.

Answer: B

66.Which of the following substances has the highest reflectivity on its surface( )

(A) yellow sand (B) dry black soil (C) snowfield (D) grassland

Answer: C

67.When the long-term operating capacitor bus voltage exceeds the rated( ) times, it should be taken out of operation.

(A) 1.1 (B) 1.3 (C) 1.2 (D) 1.4

Answer: A

68.The public connection point refers to the connection point of( ) or more users in the power system.

(A) 3 (B) 2 (C) 1 (D) 4

Answer: C

69.The reflectivity of the land surface to solar radiation is about 10%~30%. Among them, dark soil has a lower reflectivity than light soil, and rough soil has a lower reflectivity than smooth soil. The reflectivity of snow surface is approximately( ), and clean white snow can reach( ).

(A) 60%, 90%

(B) 55%, 80%

(C) 50%, 70%

(D) 65%, 100%

Answer: A

70.The operation and maintenance of the DC combiner box should comply with the following regulations( )

(A) The specifications of the fuses in the combiner box should meet the design requirements

(B) There should be no looseness or rust on the terminals inside the DC combiner box

(C) The DC combiner box should not have deformation, rust, leakage, or dust accumulation, the safety warning signs on the outer surface of the box should be intact and undamaged, and the waterproof lock on the box should operate flexibly

(D) All three options above are correct

Answer: D

71.The core device of the solar photovoltaic power generation system is( ).

(A) battery (B) inverter

(C) controller (D) solar cell

Answer: D

72.Before installing the components, each component should be inspected and tested according to the parameters of the photovoltaic components, and the usual testing items on the construction site include( ).

(A) open circuit voltage (B) working voltage

(C) working current (D) short circuit current

Answer: A

73.For a solar power supply used in an unattended color television relay station, with a voltage of 24V, daily transmission time of 15h, power consumption of 20W; the remaining 9 hours for receiving standby time, with a power consumption of 5W, the daily power consumption of the load is( )

(A) 25 Ah (B) 15 Ah (C) 12.5 Ah (D) 14.4 Ah

Answer: D

74.The “Testing Regulations for Photovoltaic Power Plant Grid Connection” applies to newly built or expanded grid-connected photovoltaic power plants connected to( ) and above voltage levels.

(A) 35 kV (B) 380 V (C) 66 kV (D) 10 kV

Answer: B

75.Utilizing concentrators to gather solar energy to heat the working medium, causing it to change from liquid to gas, driving the steam turbine generator to generate electricity is mainly( ).

(A) geothermal power generation (B) photovoltaic power generation

(C) tidal power generation (D) solar thermal power generation

Answer: D

76.The regions with the richest solar energy resources in the world are generally considered to be( ).

(A) Sahara Desert, Australia

(B) Sahara Desert, Tibet, China

(C) Tibet, China, Arabian Peninsula

(D) Sahara Desert, Arabian Peninsula

Answer: D

77.The energy storage component in the intermediate DC link of a current-type inverter is( )

(A) capacitor (B) battery (C) resistor (D) inductor

Answer: D

78.In a PWM chopper, the two input signals of the voltage comparator are triangular wave signals and DC signals, and the output signal is( ).

(A) staircase wave signal (B) sine wave signal

(C) square wave signal (D) trapezoidal wave signal

Answer: C

79.The “Technical Specifications for Photovoltaic Power Plant Grid Connection” standard stipulates that medium and large photovoltaic power plants must be able to operate for at least( ) minutes when the grid frequency is below 49.5Hz.

(A) 10 (B) 5 (C) 3 (D) 2

Answer: A

80.The following is not a basic function of the battery controller( )

(A) to charge the battery quickly, smoothly, and efficiently

(B) to charge the battery using a pulse charging method

(C) to prevent overcharging and over-discharging

(D) to provide the optimal charging current and voltage for the battery

Answer: B

81.In photovoltaic power plant design, the next level after the photovoltaic module is( )

(A) circuit breaker (B) combiner box

(C) step-up transformer (D) inverter

Answer: B

82.Which of the following photovoltaic power plants should have a certain low voltage ride-through capability?( )

(A) small and medium-sized (B) medium and large

(C) small (D) small and medium

Answer: B

83.On a solar cell module, the standard number of solar cells is( )

(A) 25 cells (B) 20 cells (C) 36 cells (D) 30 cells

Answer: C

84.According to the “Testing Regulations for Photovoltaic Power Plant Grid Connection” (Q/GDW618-2011), in the anti-islanding protection characteristic test, the relationship between the active power consumed by the RLC and the active power output by the tested power station should be( )

(A) greater than (B) equal to (C) less than (D) not necessarily

Answer: B

85.Photovoltaic power plants belong to the new energy category, and when operating in grid-connected mode, photovoltaic power plants( ).

(A) must be disconnected from the grid only after receiving instructions from the dispatch department

(B) can be disconnected from the grid by the power plant operating personnel

(C) can reconnect to the grid for power generation after being disconnected according to dispatch instructions

(D) can be disconnected from the grid by the power plant operating personnel and then report to the dispatch department

Answer: A

86.Water vapor absorption reduces solar radiation by about 4%~15%, with the strongest absorption occurring in( ) between 0.93~2.85μm.

(A) far infrared region (B) ultraviolet region

(C) visible light region (D) infrared region

Answer: D

87.According to the “Technical Specifications for Photovoltaic Power Generation System Access to Distribution Networks”, the voltage at the grid connection point of the photovoltaic power plant should be able to operate continuously within the range of( ).

(A) 93%~110% (B) 85%~110%

(C) 90%~110% (D) 80%~120%

Answer: B

88.The correct definition of the solar constant is( )

(A) the solar irradiance received on the surface of the Earth perpendicular to the solar beam at the average distance from the Earth to the Sun

(B) the solar irradiance received outside the Earth’s atmosphere perpendicular to the solar beam at the average distance from the Earth to the Sun

(C) the solar irradiance received on the surface of the Earth parallel to the solar beam at the average distance from the Earth to the Sun

(D) the solar irradiance received outside the Earth’s atmosphere parallel to the solar beam at the average distance from the Earth to the Sun

Answer: B

89.According to the “Technical Specifications for Photovoltaic Power Plant Access to Power Systems”, photovoltaic power plants connected to the grid at voltage levels of 110(66)kV and above should be equipped with( ).

(A) fault recording devices (B) temperature measurement devices

(C) irradiance measurement devices (D) module protection devices

Answer: A

90.The “Technical Specifications for Photovoltaic Power Plant Access to Power Systems” standard stipulates that the maximum limit for active power variation in large photovoltaic power plants is( ) MW within 10 minutes.

(A) installed capacity (B) installed capacity/3

(C) installed capacity/5 (D) installed capacity/10

Answer: B

91.The “Technical Specifications for Photovoltaic Power Plant Access to Power Systems” (Q/GDW617-2011) standard stipulates that photovoltaic power plants can be divided into( ) categories based on the voltage level of grid connection.

(A) 2 (B) 3 (C) 4 (D) 5

Answer: B

92.The “Technical Specifications for Photovoltaic Power Plant Access to Power Systems” (Q/GDW617-2011) standard stipulates that when the voltage at the grid connection point of the photovoltaic power plant drops to 20% of the nominal voltage, the photovoltaic power plant should be able to ensure uninterrupted grid operation for( ) seconds.

(A) 1 (B) 2 (C) 3 (D) 5

Answer: A

93.The “Technical Specifications for Photovoltaic Power Plant Access to Power Systems” (Q/GDW617-2011) standard stipulates that photovoltaic power plants should have a certain overcurrent capacity, and under 120% of the rated current, the photovoltaic power plant should be able to operate continuously and reliably for no less than( ) minutes.

(A) 1 (B) 2 (C) 3 (D) 5

Answer: A

94.The “Technical Specifications for Photovoltaic Power Plant Access to Power Systems” (Q/GDW617-2011) standard stipulates that photovoltaic power plants should provide a test report on the operational characteristics of the photovoltaic power plant to the grid company within( ) months after grid connection to demonstrate compliance with the relevant regulations for grid connection.

(A) 1 (B) 3 (C) 6 (D) 12

Answer: B

95.The “Technical Specifications for Photovoltaic Power Plant Access to Power Systems” (Q/GDW617-2011) standard stipulates that when the output active power of small photovoltaic power plants is between 20%~50%, the power factor should not be less than( ) (leading or lagging).

(A) 0.93 (B) 0.95 (C) 0.98 (D) 1

Answer: B

96.Newly installed, overhauled, or accident-repaired transformers should have a static time of no less than( ) hours before applying voltage.

(A) 12 (B) 24 (C) 48 (D) 72

Answer: B

97.The silica gel in the transformer breather should preferably use the same type of color-changing silica gel. When a large amount of silica gel changes color due to moisture, it needs to be replaced, and for single-color silica gel, the amount of moisture-affected silica gel should not exceed( ).

(A) 1/2

(B) 2/3

(C) 3/4

(D) 4/5

Answer: B

98.The main indicators of power quality management are the( ) of the power grid.

(A) voltage and frequency

(B) voltage and current

(C) frequency and current

(D) current and power factor

Answer: A

99.When a load is connected to the external circuit of the solar cell, the current flowing through the load is called the solar cell’s( ).

(A) short-circuit current (B) open-circuit current

(C) working current (D) maximum current

Answer: C

100.The color of the silica gel in the transformer breather changes to( ) after absorbing moisture.

(A) pink (B) orange (C) light blue

Answer: A

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