Photovoltaic electric appliance and charging control method, device and circuit thereof, and storage medium

Patent metadata

Field	Value
Publication number	US-12021409-B2
Application number	US-201917288027-A
Country	US
Kind code	B2
Filing date	Aug 15, 2019
Priority date	Oct 24, 2018
Publication date	Jun 25, 2024
Grant date	Jun 25, 2024

Abstract

Disclosed are a photovoltaic electric appliance and a charging control method, device and circuit thereof, and a storage medium. The charging control circuit includes: a double-relay circuit and a charging relay circuit, wherein the double-relay circuit is arranged between a grid side circuit and a machine side circuit of the photovoltaic electric appliance; and the charging relay circuit is configured to turn on to realize the gradual charging of a bus capacitor when the double-relay circuit is not turned on. A charging relay circuit is added to an alternating-current power supply side, so that when double relays are not closed, a charging relay can be closed to realize the gradual charging of a bus capacitor.

First claim

What is claimed is:

1. A charging control circuit, comprising:
a dual relay circuit arranged between a grid side circuit and a machine side circuit of a photovoltaic electric appliance;
a charging relay circuit configured to be turned on to realize gradual charging of a bus capacitance in a case where the dual relay circuit is not turned on;
a first voltage detection device configured to detect a grid side voltage at a connection point between the grid side circuit and the dual relay circuit of the photovoltaic electric appliance;
a second voltage detection device configured to detect a machine side voltage at a connection point between the machine side circuit and the dual relay circuit of the photovoltaic electric appliance; and
a charging control device configured to perform at least one of the following steps;
controlling an on state and an off state of the charging relay circuit and the dual relay circuit according to the grid side voltage and the machine side voltage; and
determining a circuit failure type according to the grid side voltage and the machine side voltage.

2. The charging control circuit according to claim 1 , wherein the charging relay circuit comprises a charging relay and a charging resistor.

3. The charging control circuit according to claim 1 , wherein:
the charging relay circuit is connected across a first end and a second end of the dual relay circuit; or
a first end of the charging relay circuit is connected to a connection point between the grid side circuit and the dual relay circuit, and a second end of the charging relay circuit is connected to a direct current bus.

4. The charging control circuit according to claim 1 , wherein the dual relay circuit comprises:
a first relay and a second relay connected in series to a neutral wire; and
a third relay and a fourth relay connected in series to a live wire.

5. The charging control circuit according to claim 4 , wherein the first relay, the second relay, the third relay, and the fourth relay are four separate alternating current relays, and the dual relay circuit comprises:
a first group of dual switch relays comprising the first relay and the third relay; and
a second group of dual switch relays comprising the second relay and the fourth relay.

6. The charging control circuit according to claim 1 , further comprising:
a third voltage detection device configured to detect a direct current bus voltage, wherein the charging control device is configured to perform at least one of the following steps:
controlling the on state and the off state of the charging relay circuit and the dual relay circuit according to the direct current bus voltage, the grid side voltage, and the machine side voltage; and
determining a circuit fault type according to the direct current bus voltage, the grid side voltage, and the machine side voltage.

7. A charging control method, comprising:
determining whether a dual relay circuit in a charging control circuit is turned on, wherein the charging control circuit is arranged between a grid side circuit and a machine side circuit of the photovoltaic electric appliance; and
turning on the charging relay circuit to realize gradual charging of the bus capacitor in the case where the dual relay circuit is not turned on;
wherein the charging control method further comprises:
obtaining a grid side voltage and a machine side voltage;
controlling an on state and an off state of the charging relay circuit and the dual relay circuit according to the grid side voltage and the machine side voltage;
obtaining the grid side voltage and the machine side voltage; and
determining a circuit fault type according to the grid side voltage and the machine side voltage; or
obtaining a grid side voltage and a machine side voltage; and
controlling the on state and the off state of the charging relay circuit and the dual relay circuit according to the grid side voltage and the machine side voltage and determining a circuit fault type according to the grid side voltage and the machine side voltage.

8. The charging control method according to claim 7 , wherein controlling the on state and the off state of the charging relay circuit and the dual relay circuit according to the grid side voltage and the machine side voltage comprises:
obtaining a direct current bus voltage;
controlling the on state and the off state of the charging relay circuit and the dual relay circuit according to a direct current bus voltage, the grid side voltage, and the machine side voltage;
obtaining the direct current bus voltage; and
determining the circuit fault type according to the direct current bus voltage, the grid side voltage, and the machine side voltage; or
obtaining a direct current bus voltage; and
controlling the on state and the off state of the charging relay circuit and the dual relay circuit according to the direct current bus voltage, the grid side voltage, and the machine side voltage, and determining a circuit fault type according to the direct current bus voltage, the grid side voltage, and the machine side voltage.

9. The charging control method according to claim 7 , wherein the charging relay circuit comprises a charging relay, the method further comprising:
controlling the on state and the off state of the charging relay circuit and the dual relay circuit according to a direct current bus voltage, the grid side voltage, and the machine side voltage, and determining the circuit fault type according to the direct current bus voltage, the grid side voltage, and the machine side voltage;
wherein controlling the on state and the off state of the charging relay circuit and the dual relay circuit according to the direct current bus voltage, the grid side voltage, and the machine side voltage, and determining the circuit fault type according to the direct current bus voltage, the grid side voltage, and the machine side voltage comprises:
determining whether an effective value of the grid side voltage and an effective value of the machine side voltage satisfy a first condition that the effective value of the grid side voltage is within a first predetermined range, and the effective value of the machine side voltage is less than a predetermined value;
turning on the charging relay in a case where the effective value of the grid side voltage and the effective value of the machine side voltage satisfy the first condition; and
determining a relay failure, and reporting a message of the relay failure to the outside in a case that the effective value of the grid side voltage and the effective value of the machine side voltage do not satisfy a first condition, wherein the relay failure is that a first relay, a second relay, a third relay, and a fourth relay of the dual relay circuit are all short-circuited.

10. The charging control method according to claim 9 , wherein determining the circuit fault type according to the direct current bus voltage, the grid side voltage, and the machine side voltage further comprises:
determining whether the direct current bus voltage satisfies a second condition within a first predetermined time interval after turning on the charging relay, wherein the second condition is that the direct current bus voltage is greater than a predetermined voltage; and
determining that the direct current bus is short-circuited, and reporting a message of short-circuit of the direct current bus to the outside in a case where the direct current bus voltage does not satisfy the second condition within the first predetermined time interval after turning on the charging relay.

11. The charging control method according to claim 10 , wherein determining the circuit fault type accordi

Assignees

• Gree Electric Appliances Inc Zhuhai

Inventors

• Liu Han
• Chen Ningning
• Zhang Xuefen
• Liu Keqin

Classifications

• H02J7/933

  the cycle being controlled or terminated in response to electric parameters · CPC title

• H02J7/80

  including monitoring or indicating arrangements · CPC title

• H02J7/60

  including safety or protection arrangements · CPC title

• H02J7/90

  Regulation of charging or discharging current or voltage · CPC title

• H02J7/345

  using capacitors as storage or buffering devices · CPC title