Solar power generation system

• US 10,454,417 B2
• Filed: 04/08/2016
• Issued: 10/22/2019
• Est. Priority Date: 04/08/2016
• Status: Active Grant

• Current Assignee: Tmeic Corporation (Toshiba Corporation)
• Original Assignee: Mitsubishi Electric Corporation
• Inventors: Matsuoka, Yuji, Ikawa, Eiichi
• Primary Examiner(s): Torres-Rivera, Alex
• Application Number:
  US16/091,594
• Publication Number:
  US 20190089300A1
• Time in Patent Office: 1,292 Days
• Field of Search: 323906, 363 95, 363 96, 363 97, 363 98, 363131, 363132, 363133, 363134, 363135, 363136, 363137
• CPC Class Codes: H02J 2300/26 involving maximum power point tracking control for photovoltaic sources
• CPC Class Codes: H02J 3/381 Dispersed generators
• CPC Class Codes: H02M 7/48 using discharge tubes with control electrode or semiconductor devices with control electrode
• CPC Class Codes: H02M 7/537 using semiconductor devices only, e.g. single switched pulse inverters
• CPC Class Codes: H02M 7/53871 with automatic control of output voltage or current
• CPC Class Codes: H02S 40/32 comprising DC/AC inverter means associated with the PV module itself, e.g. AC modules
• CPC Class Codes: H02S 50/00 Monitoring or testing of PV systems, e.g. load balancing or fault identification
• CPC Class Codes: Y02E 10/56 Power conversion systems, e.g. maximum power point trackers

Abstract

A solar power generation system includes an inverter configured to convert DC power inputted from a solar battery to AC power, a MPPT control section configured to perform maximum power point tracking control on the inverter, an input power measurement section configured to measure the DC power inputted to the inverter at a time of avoiding a transient state due to variation in DC voltage of the inverter by the maximum power point tracking control, an output power measurement section configured to measure the AC power outputted from the inverter at the time of avoiding the transient state, and a conversion efficiency computation section configured to compute conversion efficiency of the inverter based on the DC power measured by the input power measurement section and the AC power measured by the output power measurement section.

Claims

1. A solar power generation system comprising:

an inverter configured to convert DC power inputted from a solar battery to AC power;

a maximum power point tracking control section configured to perform maximum power point tracking control on the inverter;

an input power measurement section configured to measure the DC power inputted to the inverter at a time of avoiding a transient state due to variation in DC voltage of the inverter by the maximum power point tracking control;

an output power measurement section configured to measure the AC power outputted from the inverter at the time of avoiding the transient state;

a conversion efficiency computation section configured to compute conversion efficiency of the inverter based on the DC power measured by the input power measurement section and the AC power measured by the output power measurement section; and

a transient state avoidance signal output section configured to output a transient state avoidance signal for performing measurement at a time of avoiding the transient state each time the transient state avoidance signal output section outputs an instruction for varying the DC voltage of the inverter by the maximum power point tracking control, wherein

the input power measurement section measures the DC power based on the transient state avoidance signal outputted from the transient state avoidance signal output section, and

the output power measurement section measures the AC power based on the transient state avoidance signal outputted from the transient state avoidance signal output section.

2. The system according to claim 1, further comprising:

a measurement synchronization section configured to perform control for synchronization so that measurement by the input power measurement section and measurement by the output power measurement section are made simultaneous.

3. The system according to claim 1, further comprising:

a measurement synchronization section configured to perform control for synchronization so that measurement by the input power measurement section and measurement by the output power measurement section are made simultaneous.

4. A control device for a solar power generation system including an inverter configured to convert DC power inputted from a solar battery to AC power, the device comprising:

a maximum power point tracking control section configured to perform maximum power point tracking control on the inverter;

an input power measurement section configured to measure the DC power inputted to the inverter at a time of avoiding a transient state due to variation in DC voltage of the inverter by the maximum power point tracking control;

an output power measurement section configured to measure the AC power outputted from the inverter at the time of avoiding the transient state;

a conversion efficiency computation section configured to compute conversion efficiency of the inverter based on the DC power measured by the input power measurement section and the AC power measured by the output power measurement section; and

a transient state avoidance signal output section configured to output a transient state avoidance signal for performing measurement at a time of avoiding the transient state each time the transient state avoidance signal output section outputs an instruction for varying the DC voltage of the inverter by the maximum power point tracking control, wherein

the input power measurement section measures the DC power based on the transient state avoidance signal outputted from the transient state avoidance signal output section, and

the output power measurement section measures the AC power based on the transient state avoidance signal outputted from the transient state avoidance signal output section.

5. The device according to claim 4, further comprising:

a measurement synchronization section configured to perform control for synchronization so that measurement by the input power measurement section and measurement by the output power measurement section are made simultaneous.

6. The device according to claim 4, further comprising:

a measurement synchronization section configured to perform control for synchronization so that measurement by the input power measurement section and measurement by the output power measurement section are made simultaneous.

7. A control method for a solar power generation system including an inverter configured to convert DC power inputted from a solar battery to AC power, the control method comprising:

performing maximum power point tracking control on the inverter;

measuring the DC power inputted to the inverter at a time of avoiding a transient state due to variation in DC voltage of the inverter by the maximum power point tracking control;

measuring the AC power outputted from the inverter at the time of avoiding the transient state;

computing conversion efficiency of the inverter based on the measured DC power and the measured AC power; and

outputting a transient state avoidance signal for performing measurement at a time of avoiding the transient state each time an instruction for varying the DC voltage of the inverter by the maximum power point tracking control is outputted, wherein

measurement of the DC power is performed based on the transient state avoidance signal, and

measurement of the AC power is performed based on the transient state avoidance signal.

8. The method according to claim 7, further comprising:

performing control for synchronization so that measurement of the DC power and measurement of the AC power are made simultaneous.

9. The method according to claim 7, further comprising:

performing control for synchronization so that measurement of the DC power and measurement of the AC power are made simultaneous.